Database: MEDLINE <: biomedical, nursing & dental literature, 1966 - Oct 2000.> Search Strategy (You Saved Citations 1-300 From Set 60): ----------------------------------------------------------------------------- 1 Actinomycetaceae/ 441 2 exp Actinomyces/ 2796 3 actinomyce:.mp. 9374 4 odontomyces.mp. 5 5 Actinomycetales/ 2287 6 or/1-5 9375 7 viscosus.mp. 661 8 naeslundi$.mp. 340 9 or/7-8 824 10 6 and 9 793 11 or/1-4 9375 12 10 or 11 9375 13 exp Tooth demineralization/ 22628 14 demineralization.mp. 1620 15 caries.mp. 15295 16 caires.mp. 1 17 craies.mp. 0 18 careis.mp. 4 19 carise.mp. 0 20 (teeth adj3 cavit:).mp. 422 21 (tooth adj3 cavit:).mp. 217 22 (dental adj3 cavit:).mp. 276 23 (dentin adj3 cavit:).mp. 254 24 (enamel adj3 cavit:).mp. 182 25 (teeth adj3 decay:).mp. 374 26 (tooth adj3 decay:).mp. 321 27 (dental adj3 decay:).mp. 250 28 (dentin adj3 decay:).mp. 12 29 (enamel adj3 decay:).mp. 20 30 (active adj decay).mp. 9 31 (rampant adj3 decay:).mp. 14 32 (recurrent adj3 decay:).mp. 30 33 (white adj spot:).mp. 509 34 carious.mp. 2077 35 cariology.ti,ab. 56 36 (non-cavitated adj3 lesion:).mp. 15 37 (noncavitated adj3 lesion:).mp. 2 38 Tooth remineralization/ 478 39 (dental adj3 fissure:).mp. 99 40 (tooth adj3 fissure:).mp. 50 41 (teeth adj3 fissure:).mp. 98 42 caries-free.mp. 603 43 cariesfree.mp. 17 44 Cariogenic agents/ 728 45 precavit:.mp. 8 46 (filled adj3 teeth).mp. 510 47 (filled adj3 tooth).mp. 117 48 (oral adj fissure:).mp. 6 49 (tooth adj3 remineraliz:).mp. 28 50 (teeth adj3 remineraliz:).mp. 24 51 dft.mp. 413 52 dfs.mp. 1258 53 dmf:.mp. 6397 54 cariogeni:.mp. 1787 55 or/13-54 32256 56 Dental plaque/ 10264 57 ((tooth or teeth or dent:) adj3 (placque or plaque)).mp. 3494 58 or/55-57 40621 59 12 and 58 977 60 limit 59 to (human and english language) 700 61 from 60 keep 1-300 300 *************************** <1> UI - 20265399 AU - Shiloah J AU - Patters MR AU - Waring MB IN - Department of Periodontology, College of Dentistry, The University of Tennessee, Memphis 38163, USA. jshiloah@utmem.edu TI - The prevalence of pathogenic periodontal microflora in healthy young adult smokers. SO - Journal of Periodontology 2000 Apr;71(4):562-7 AB - BACKGROUND: Smoking is a major risk factor in periodontitis, although the mechanisms of its effects are not well understood. The overall goal of this clinical study was to determine if smoking enhances the colonization of the oral cavity by pathogenic bacteria in a periodontitis-free population. The prevalence of Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, Fusobacterium nucleatum, Campylobacter rectus, Eikenella corrodens, Bacteroides forsythus, and Treponema denticola was investigated in 25 smokers and 25 non-smokers by using DNA probes. METHODS: The subjects were 21 to 35 years of age with a healthy periodontium or slight gingivitis and were systemically healthy. The test group included subjects who had a minimum of a 1.5 pack-year history of smoking, while the control subjects never smoked. Subgingival plaque samples were taken by paper point following the assessment of multiple clinical parameters. RESULTS: This investigation showed: 1) no statistically significant differences were noted in any clinical parameter measured between the groups; 2) of the 8 subjects who were infected by at least 1 tested pathogen, seven were smokers (P= 0.02); 3) infected smokers had a 15.7+/-3.5 pack-year history and smoked a mean of 27+/-5 cigarettes/day versus 4.4+/-0.8 pack years and 15+/-1 cigarettes/day for the non-infected smokers (P = 0.0001 and P = 0.004); and 4) smokers were 18 times more likely to exhibit the presence of pathogens than non-smokers. CONCLUSIONS: These data indicate that the prevalence of colonization of the sulcus by pathogenic bacterial species in periodontitis-free individuals is related to the quantity and duration of cigarette smoking. <2> UI - 20331205 AU - Nakou M AU - Mikx FH AU - Oosterwaal PJ AU - Kruijsen JC IN - Department of Conservative Dentistry (Periodontology), University of Athens, Greece. TI - Early microbial colonization of permucosal implants in edentulous patients. SO - Journal of Dental Research 1987 Nov;66(11):1654-7 AB - In edentulous patients, the microbial colonization of permucosal implants of sintered hydroxyapatite was studied. Samples were taken from mucosa and dentures before insertion of implants and from supra- and subgingival sites two to 10 weeks after insertion. In total, five patients and 10 implants with clinically healthy peri-implant tissues were studied. The samples were investigated by dark-field microscopy and anaerobic culture. The supragingival plaque of the implants was dominated by Gram-positive cocci and rods, the subgingival plaque by Haemophilus spp. and Veillonella parvula. A group of bacteria was found specifically related to the implants: Actinomyces odontolyticus, Peptostreptococcus micros, Haemophilus actinomycetemcomitans, Eikenella corrodens, Capnocytophaga sputigena, and Leptotrichia buccalis. Black-pigmented Bacteroides was not found in any of the examined samples. Spirochetes were observed in denture plaque samples and in supragingival plaque of the implants. It is concluded that bacteria known as potential periodontal pathogens colonize the permucosal implants in the first weeks after insertion. The presence of these species seems to be dependent on the ecological factors provided by the artificial gingival crevice of the permucosal implants in the edentulous mouth. <3> UI - 20328541 AU - Levine M AU - Movafagh BF AU - Schwartzott DL IN - Department of Biochemistry and Molecular Biology, University of Oklahoma at Oklahoma City 73190, USA. TI - Characterization and cross-reactivity of rabbit antisera to plaque toxins. SO - Oral Microbiology & Immunology 1987 Jun;2(2):88-91 AB - The effects of heat labile, high molecular weight water-soluble toxins from bacterial plaque on HL60 promyelocytic cells were examined. On gel filtration, four inhibitors of HL60 cell growth and two inhibitors of HeLa cell growth (PT1, PT2) were detected. The first and third HL60 cell inhibitors corresponded to the two HeLa cell inhibitors. The last eluted HL60 cell inhibitor (plaque leukotoxin, PL) did not inhibit HeLa cell growth. Anti-PT2 antibodies reduced the activity of enriched PT2 by 20-50%, but all other antisera tested exhibited no effect. Anti-PL antibodies detected antigens from Actinobacillus actinomycetemcomitans, although anti-A. actinomycetemcomitans and anti-Capnocytophaga sputigena antibodies did not react with plaque extract. These findings suggest that the plaque toxins examined in this study were probably not derived from these two bacteria. <4> UI - 20328538 AU - Delaney JE AU - Kornman KS IN - Department of Pediatric Dentistry, University of Texas Health Science Center at San Antonio 78284, USA. TI - Microbiology of subgingival plaque from children with localized prepubertal periodontitis. SO - Oral Microbiology & Immunology 1987 Jun;2(2):71-6 AB - Localized prepubertal periodontitis has been described as a host-defect mediated form of bacterially induced periodontitis, with an early onset and rapid progression around a few teeth in children prior to puberty. To further our understanding of the etiology of this disease, we have examined the microbiological components of subgingival dental plaque in 9 children with localized prepubertal periodontitis to determine if patterns of putative pathogens existed, and have compared these results with those obtained from 4 children with no periodontitis. Subgingival plaque samples were plated onto a selective medium for Actinobacillus actinomycetemcomitans and onto a non-selective medium for anaerobes, and the predominant cultivable microbiota of 2 sites per child was determined. The subgingival microbiota of children with localized prepubertal periodontitis clearly differs from non-diseased children in the detection of high levels of several suspected pathogens, including A. actinomycetemcomitans, Bacteroides intermedius, Eikenella corrodens, and Capnocytophaga sputigena. These putative pathogens were found in various combinations. These findings suggest that localized prepubertal periodontitis is associated with specific subgingival bacteria which are generally not found in children without periodontitis. <5> UI - 20328536 AU - Frisken KW AU - Tagg JR AU - Laws AJ AU - Orr MB IN - Department of Periodontology, School of Dentistry, University of Otago, Dunedin, New Zealand. TI - Suspected periodontopathic microorganisms and their oral habitats in young children. SO - Oral Microbiology & Immunology 1987 Jun;2(2):60-4 AB - Samples of subgingival plaque from 67 children, 5-7 years of age, were examined for the presence of certain suspected periodontal pathogenic species using the conventional technique of anaerobic sonification, dilution and spiral plating. When this technique was compared with a direct plating procedure which involved no preliminary dispersion and dilution of plaque specimens, it was found that the direct method resulted in double the frequency of children in whom black-pigmented Bacteroides (BPB) were detected and a 10-times increase in the number of subjects harbouring Actinobacillus actinomycetemcomitans. Samples from the tongue, tonsils and saliva were also plated using the direct technique. BPB were detected less commonly in the plaque specimens (61.3% of children) than in saliva (89.5%), or on the tongue (86.6%) and tonsils (97.1%). Expressed as percentages of a pooled sample of the total BPB population, the most frequently detected species in plaque were Bacteroides intermedius (44.4%) and Bacteroides melaninogenicus (48.0%). The most prevalent isolate in all other oral sites was B. melaninogenicus. Expressed as percentages of children in whom BPB were detected, the most frequently isolated species from plaque using the conventional dilution technique was B. intermedius (21.3%), whereas other BPB species were present in fewer than 5% of children. Fusobacterium nucleatum and Capnocytophaga species were isolated most frequently from plaque but were also commonly detected in the various other oral sites. <6> UI - 20328535 AU - Ebersole JL AU - Taubman MA AU - Smith DJ AU - Frey DE AU - Haffajee AD AU - Socransky SS IN - Department of Periodontics, University of Texas Health Science Center at San Antonio 78284, USA. TI - Human serum antibody responses to oral microorganisms. IV. Correlation with homologous infection. SO - Oral Microbiology & Immunology 1987 Jun;2(2):53-9 AB - Recent microbiological studies of periodontal disease in humans have supported the concept of a specific bacterial etiology. While individual agents have not been unequivocally identified, numerous Gram-negative members of the subgingival microflora have been implicated. In addition, elevations in systemic antibody responses have been consistent with certain oral microorganisms being involved in an infectious process associated with the disease. This report delineates the relationship between elevated systemic antibody levels and oral colonization with the homologous microorganism at active disease sites. Thirty-four patients with various types of periodontal disease were examined. Using ELISA, each patient was shown to have an elevated antibody response to at least one organism from a battery of 18 oral microorganisms that were tested. Subsequently, subgingival plaque was cultured from disease-active and -inactive sites of each subject. The results demonstrated that the same microorganism to which the individual exhibited elevated serum antibody responses was detected in nearly 55% of the disease-active sites, while only 18% of the inactive sites showed the microorganism. Certain microorganisms including Actinobacillus actinomycetemcomitans, Bacteroides gingivalis, Eikenella corrodens and Wolinella recta were primarily or exclusively correlated with active disease lesions. These findings support the hypothesis that elevated systemic antibodies to periodontopathic bacteria are reflective of subgingival colonization and exist as a response to a bacterial infection at disease-active sites. <7> UI - 20236685 AU - Morinushi T AU - Lopatin DE AU - Van Poperin N AU - Ueda Y IN - Department of Pediatric Dentistry, Kagoshima University Dental School, Japan. TI - The relationship between gingivitis and colonization by Porphyromonas gingivalis and Actinobacillus actinomycetemcomitans in children. SO - Journal of Periodontology 2000 Mar;71(3):403-9 AB - BACKGROUND: Porphyromonas gingivalis and Actinobacillus actinomycetemcomitans are closely associated with the onset and severity of adult periodontal disease. However, little is known regarding the colonization by, and host antibody response to, these microorganisms in children. METHODS: Plaque and sera were obtained from 40 healthy children, 2 to 18 years old. Gingival health was assessed by the periodontal disease index (PDI), papillary bleeding score (BS) and the modified total papillary margin attachment index (M-PMA). P. gingivalis and A. actinomycetemcomitans in plaque samples were detected by slot immunoblotting (SIB). Serum antibody levels against these microorganisms were evaluated using ELISA. RESULTS: More than 60% of the children had detectable levels of P. gingivalis in their plaque. Those having detectable levels had more gingival inflammation than those having none; however, these differences were significant only in children over the age of 12 years (PDI, BS). In contrast, while 75% of the children had detectable A. actinomycetemcomitans, there were significant differences in gingival inflammation associated with colonization in children from 3 to 7 years of age (PDI) and over 12 years of age (M-PMA). Serum antibody levels to P. gingivalis were inversely correlated with gingival inflammation in all age groups, while A. actinomycetemcomitans titers were positively correlated with gingival inflammation only in the children over 12 years. No significant relationship between the presence of either A. actinomycetemcomitans or P. gingivalis and antibodies to them was found. CONCLUSIONS: Our findings show that P. gingivalis and A. actinomycetemcomitans are readily detected as early as 3 years of age and that their presence is associated with the onset and severity of gingivitis. <8> UI - 20236684 AU - Pattni R AU - Walsh LJ AU - Marshall RI AU - Cullinan MP AU - Seymour GJ AU - Bartold PM IN - University of Queensland, Department of Dentistry, Brisbane, Australia. TI - Changes in the periodontal status of patients undergoing bone marrow transplantation. SO - Journal of Periodontology 2000 Mar;71(3):394-402 AB - BACKGROUND: Patients receiving an HLA-matched bone marrow transplant (BMT) from a relative or unrelated donor undergo a permanent alteration of their immune system, followed by a prolonged period of immunodeficiency. This study aimed to examine alterations in the periodontal status of patients over 6 months post-bone marrow transplantation. METHODS: Thirty-seven patients scheduled for bone marrow transplantation participated in this study. One calibrated examiner carried out periodontal examinations (clinical and radiographic) immediately prior to and at 3 and 6 months after transplantation. All patients followed an intense oral care program. Subgingival plaque samples were analyzed by enzyme-linked immunosorbent assay (ELISA) for the presence of Porphyromonas gingivalis, Actinobacillus actinomycetemcomitans, and Prevotella intermedia. Data were subjected to statistical analyses to determine the relationships between the frequency distribution of the radiographic and clinical variables over time. RESULTS: Gains in clinical attachment level (CAL) of > or =2 mm at 4 or more sites from baseline to 6 months post-BMT were noted in 9/16 patients (56%), while 6/16 (38%) patients experienced a loss of CAL > or =2 mm at 4 or more sites in the same period. At a site level, 4.8% of sites exhibited a gain in CAL > or =2 mm between baseline and 3 months post-BMT while 2.3% of sites showed a loss of CAL > or =2 mm in the same period. From baseline to 6 months, a gain in CAL of > or =2 mm was recorded at 3.1% of sites, and 2.4% of sites experienced a loss of > or =2 mm. A significant improvement in the gingival index occurred between all sequential time periods when assessed at a site level. At a patient level, 11/18 (61%) patients showed a significant change in gingival index between baseline and 3 months and 10/16 (63%) between baseline and 6 months. There was no significant relationship between clinical changes and the prevalence of the periodontal pathogens at the various time periods. CONCLUSIONS: An improvement in periodontal health was recorded between baseline and 6 months post-transplantation. Most of the improvement in periodontal status was noted in the first 3 months after BMT, with a slight decline in periodontal health between 3 and 6 months post-transplant. No significant alteration was noted in the prevalence of periodontal pathogens during the study period. <9> UI - 20250369 AU - Kamma JJ AU - Diamanti-Kipioti A AU - Nakou M AU - Mitsis FJ IN - Department of Periodontology, School of Dental Medicine, University of Athens, Greece. kvich@tee.gr TI - Profile of subgingival microbiota in children with primary dentition. SO - Journal of Periodontal Research 2000 Feb;35(1):33-41 AB - Eruption of primary teeth has a great influence on the oral environment by providing suitable niches for bacterial colonization. The aim of the study was to investigate the composition of the subgingival microbiota of primary incisors, canines and molars in 40 systemically healthy children aged 4-5 yr, chosen randomly. Subgingival plaque samples were taken from the mesiobuccal sites of primary incisors (61, 81), canines (53, 73) and molars (64, 84). The samples were cultured for bacterial isolation anaerobically and in 10% CO2 plus air using selective and non-selective media. Forty-one different microbial species were isolated. Gemella morbillorum and Peptostreptococcus magnus were statistically significantly more frequently detected in incisors while P. micros, Streptococcus intermedius, Bacteroides forsythus, Fusobacterium nucleatum, Prevotella loeschei, P. melaninogenica and Selenomonas sputigena were more frequently detected in molars. The bacterial species S. constellatus, G. morbillorum and P. magnus were isolated in greater numbers in incisors and P. micros, S. intermedius, Campylobacter concisus, Bacteroides egertheii, B. forsythus, P. oralis and S. sputigena were isolated in greater numbers in molars, respectively. Cluster analysis revealed 4 clusters in which 6-7 bacterial species were elevated above mean levels. Cluster I was predominated by S. constellatus, S. mitis, S. sanguis, G. morbillorum, P. melaninogenica and P. oralis; cluster II was predominated by S. sanguis, Actinomyces naeslundii, Capnocytophaga gingivalis, C. ochracea and P. intermedia; cluster III was predominated by S. mitis, C. ochracea, F. nucleatum, P. loeschei, P. melaninogenica and P. oralis; and finally cluster IV was predominated by S. sanguis, C. gingivalis, Veillonella parvula, Campylobacter gracilis, F. nucleatum and P. intermedia. The bacterial species S. constellatus, P. micros, Pseudoramibacter alactolyticus, Eikenella corrodens and F. nucleatum were associated with non-bleeding sites while S. intermedius, C. concisus, P. intermedia and P. loescheii were found more frequently in bleeding sites. <10> UI - 20250367 AU - Ting M AU - Contreras A AU - Slots J IN - Department of Periodontology, University of Southern California, School of Dentistry, Los Angeles, 90089-0641, USA. TI - Herpesvirus in localized juvenile periodontitis. SO - Journal of Periodontal Research 2000 Feb;35(1):17-25 AB - Herpesvirus genomic sequences can be detected in gingival crevicular fluid of adult periodontitis lesions. Herpesviruses are immunosuppressive and may facilitate establishment of subgingival pathogens. Electron microscopic studies have identified nuclear and cytoplasmic virus-like inclusions in gingival inflammatory cells from localized juvenile periodontitis (LJP). The present study aimed to determine if herpesviruses occur in LJP lesions and if human cytomegalovirus (HCMV) activation is associated with elevated levels of subgingival Actinobacillus actinomycetemcomitans, the putative bacterial pathogen of LJP. Eleven systemically healthy patients exhibiting LJP (10-23 yr) were studied. In each patient, subgingival samples were pooled from 3 periodontitis lesions around first molar and incisor teeth (5-11 mm periodontal pocket depth) and from 3 gingivitis/healthy sites around canines (2-3 mm periodontal pocket depth). Polymerase chain reaction (PCR) was used to detect herpesvirus DNA and HCMV cDNA of major capsid protein transcripts, indicative of viral activation. Selective culture and 16S rRNA PCR were used to identify A. actinomycetemcomitans. Of 11 deep periodontal samples, 8 showed HCMV, 7 showed Epstein-Barr virus type 1 (EBV-1), 1 showed EBV type 2, 6 showed herpes simplex virus (HSV) and 8 showed viral co-infection. Of 11 shallow periodontal samples, 2 showed HCMV, 2 showed EBV-1, 1 showed HSV and 2 showed viral co-infection. The difference in occurrence of HCMV and viral co-infection between deep and shallow periodontal sites was statistically significant (p =0.031). HCMV activation was detected in deep pockets of all 5 virally positive patients with early LJP (aged 10-14 years) but only in 1 of 3 virally positive LJP patients older than 14 years, and not in any shallow pocket tested. HCMV activation appeared related to absence of radiographic crestal alveolar lamina dura, a possible indication of periodontal disease progression. A. actinomycetemcomitans tended to be more prevalent in samples showing active than latent HCMV infection. The present findings are consistent with the notion that periodontal herpesvirus infection and possibly HCMV activation constitute important features of the etiopathogenesis of LJP. <11> UI - 20274738 AU - Levy RM AU - Giannobile WV AU - Feres M AU - Haffajee AD AU - Smith C AU - Socransky SS IN - Department of Periodontology, Forsyth Institute, Boston, Massachusetts 02115, USA. TI - The short-term effect of apically repositioned flap surgery on the composition of the subgingival microbiota. SO - International Journal of Periodontics & Restorative Dentistry 1999 Dec;19(6):555-67 AB - The purpose of this investigation was to examine the short-term effect of apically repositioned flap surgery on clinical and microbiologic parameters in patients with adult periodontitis. A total of 11 patients with moderate to advanced periodontitis received apically repositioned flap surgery. Subjects were monitored during a 3-month pretreatment phase, the baseline surgical phase, and for 3 months post-surgery. Clinical assessments including plaque accumulation, gingival redness, suppuration, bleeding on probing, pocket depth, and attachment level were made at 6 sites per tooth. Subgingival plaque samples were taken from the mesial aspect of each tooth and the presence and levels of 29 subgingival taxa were determined using whole genomic DNA probes and checkerboard DNA-DNA hybridization. The mean levels and percentage of sites colonized by each species (prevalence) were computed for each subject at each visit. After surgery, there was a significant decrease in mean pocket depth and percentage of sites exhibiting gingival redness. Significant decreases were seen in the percentage of sites that had attachment levels < 4 mm, with a significant increase in the percentage of sites with attachment levels of 4 to 6 mm after therapy. The mean total DNA probe count for all bacterial species was significantly decreased by both scaling and root planing and surgical therapy. P gingivalis and B forsythus, 2 bacteria previously shown to be susceptible to mechanical therapy, exhibited statistically significant decreases in mean total DNA probe count. Because surgical therapy decreased levels of the suspected periodontal pathogens C rectus, P nigrescens, and C gracilis, it may be speculated that there was a potential added beneficial effect of surgery on the periodontal microbiota. <12> UI - 20221171 AU - Yeung MK IN - Department of Pediatric Dentistry, University of Texas Health Science Center at San Antonio, 78284, USA. TI - Molecular and genetic analyses of Actinomyces spp. [Review] [132 refs] SO - Critical Reviews in Oral Biology & Medicine 1999;10(2):120-38 AB - Members of the genus Actinomyces are predominant primary colonizers of the oral cavity and play an important role in initiating plaque development. These bacteria have evolved unique mechanisms that favor colonization and persistence in this micro-environment. The expression of cell-surface fimbriae is correlated with the ability of these bacteria to adhere to specific receptors on the tooth and mucosal surfaces, and to interact with other plaque bacteria. The elaboration of sialidase is thought to enhance fimbriae-mediated adherence by unmasking the fimbrial receptors on mammalian cells. The presence of certain cell-associated or extracellular enzymes, including those involved in sucrose or urea metabolism, may provide the means for these bacteria to thrive under conditions when other growth nutrients are not available. Moreover, these enzyme activities may influence the distribution of other plaque bacteria and promote selection for Actinomyces spp. in certain ecological niches. The recent development of a genetic transfer system for Actinomyces spp. has allowed for studies the results of which demonstrate the existence of multiple genes involved in fimbriae synthesis and function, and facilitated the construction of allelic replacement mutants at each gene locus. Analyses of these mutants have revealed a direct correlation between the synthesis of assembled fimbriae and the observed adherence properties. Further genetic analysis of the various enzyme activities detected from strains of Actinomyces should allow for an assessment of the role of these components in microbial ecology, and their contribution to the overall success of Actinomyces spp. as a primary colonizer and a key player in oral health and disease. [References: 132] <13> UI - 20174757 AU - Amano A AU - Kishima T AU - Kimura S AU - Takiguchi M AU - Ooshima T AU - Hamada S AU - Morisaki I IN - Division of Special Care Dentistry, Osaka University Faculty of Dentistry, Suita-Osaka, Japan. amanoa@dent.osaka-u.ac.jp TI - Periodontopathic bacteria in children with Down syndrome. SO - Journal of Periodontology 2000 Feb;71(2):249-55 AB - BACKGROUND: It is widely known that individuals with Down syndrome (DS) often develop severe early-onset periodontal diseases. In this study, we examined the prevalence of periodontopathic bacteria in DS children to determine if specific pathogens are acquired in their childhood. METHODS: The subjects were 60 DS children (2 to 13 years old, 5 in each age bracket) and 60 age-matched controls. Ten pathogens, Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Bacteroides forsythus, Treponema denticola, Prevotella intermedia, P nigrescens, Capnocytophaga ochracea, C. sputigena, Campyrobacter rectus, and Eikenella corrodens were surveyed in subgingival plaque samples using a polymerase chain reaction. Periodontal status was evaluated by probing depth, bleeding on probing, and gingival index. RESULTS: No significant difference in periodontal status was observed between the DS and control groups, however, all of the pathogens were detected with greater frequency in the DS children. B. forsythus, T. denticola, P. nigrescens, and C. rectus were significantly prevalent throughout all age brackets of the DS children (P <0.01 or 0.05). The occurrence of P. gingivalis was also significant in the DS subjects over 5 years old. A cluster analysis of the microbial profiles of the DS subjects showed that gingivitis severity was associated with increased varieties of the harboring pathogens and the distribution of P. gingivalis. CONCLUSIONS: These results suggest that various periodontopathogens can colonize in the very early childhood of DS patients and maturation of subgingival components, including P. gingivalis, plays an important role in the initiation of gingival inflammation. <14> UI - 20174752 AU - Kleinfelder JW AU - Mueller RF AU - Lange DE IN - Section of Periodontology, College of Dentistry, The Ohio State University, Columbus, USA. TI - Fluoroquinolones in the treatment of Actinobacillus actinomycetemcomitans-associated periodontitis. SO - Journal of Periodontology 2000 Feb;71(2):202-8 AB - BACKGROUND: Periodontitis patients harboring Actinobacillus actinmycetemcomitans (Aa) are prime candidates for systemic antibiotic therapy. Besides tetracycline and the combination of metronidazole and amoxicillin the fluoroquinolones are also believed to have antibacterial activity against Aa. The aim of the present study was to evaluate systemic ofloxacin therapy as adjunct to flap surgery. METHODS: Twenty-five adult periodontitis patients with subgingival detection of Aa were treated with 2x200 mg/d ofloxacin for 5 days as adjunct to open flap surgery (test). Another 10 patients received only flap surgery (control). Probing depth (PD) and clinical attachment level (CAL) was recorded and subgingival plaque samples were cultivated on TSBV agar for detection of Aa at baseline as well as 3 and 12 months following therapy. RESULTS: At 3 and 12 months following therapy mean PD at monitored sites in the test group changed from 6.8 mm (+/-1.3) to 3.6 mm (+/-1.0), 3.8 mm (+/-1.1) and CAL from 7.5 mm (+/-1.4) to 5.4 mm (+/-1.4), 5.5 mm (+/-1.3). In the control group PD changed from 6.5 mm (+/-0.7) to 4.0 mm (+/-1.7), 4.1 mm (+/-1.6) and CAL from 7.5 mm (+/-1.0) to 6.3 mm (+/-1.7), 6.4 mm (+/-1.8). P was <0.05 for CAL between groups. Three and 12 months following adjunctive systemic ofloxacin therapy, Aa was suppressed below detectable levels in 22 of 22, test patients, whereas Aa could not be recovered in only 2 of the 10 controls. (P<0.0001). CONCLUSIONS: Systemic ofloxacin as adjunct to open flap surgery is able to suppress A. actinomycetemcomitans below detectable level in patients harboring this organism at baseline. <15> UI - 97411367 AU - Winkel EG AU - Van Winkelhoff AJ AU - Timmerman MF AU - Vangsted T AU - Van der Velden U IN - Department of Periodontology, Academic Centre for Dentistry, Amsterdam, The Netherlands. TI - Effects of metronidazole in patients with "refractory" periodontitis associated with Bacteroides forsythus [see comments]. CM - Comment in: J Clin Periodontol 1999 Nov;26(11):764-6 SO - Journal of Clinical Periodontology 1997 Aug;24(8):573-9 AB - The aim of the present study was to monitor the microbiological and clinical effects of renewed supra- and subgingival debridement in conjunction with systemic metronidazole therapy (500 mg TID for 7 days) in 27 "refractory" periodontitis patients, culture positive for Bacteroides forsythus and negative for Actinobacillus actinomycetemcomitans. Clinical evaluation included assessment of plaque, bleeding upon probing, probing pocket depth and clinical attachment loss at the deepest, bleeding site in each quadrant. Microbiological evaluation was carried out by anaerobic cultivation of subgingival plaque samples from the same sites. 6 months after renewed debridement and systemic metronidazole (RD+M), a statistically significant improvement of all clinical parameters was observed, except for the plaque index. After RD+M, B. forsythus was suppressed below detection level in 17 of the 27 patients, P. gingivalis in 9 out of 15 patients and P. intermedia in 14 of the 21 patients. Before RD+M, 12 patients harboured simultaneously B. forsythus, P. gingivalis as well as P. intermedia. Out of these, 6 patients were culture negative for the 3 species after therapy and showed the greatest reduction in pocket depth (3.1 mm) and gain of clinical attachment level (2.5 mm). In the treatment of refractory periodontitis, associated with patients culture positive for B. forsythus and negative for A. actinomycetemcomitans, metronidazole can significantly improve the clinical and microbiological parameters. <16> UI - 20170217 AU - Pollanen MT AU - Salonen JI AU - Grenier D AU - Uitto VJ IN - Institute of Dentistry, University of Turku, Finland. marja.pollanen@utu.fi TI - Epithelial cell response to challenge of bacterial lipoteichoic acids and lipopolysaccharides in vitro. SO - Journal of Medical Microbiology 2000 Mar;49(3):245-52 AB - Accumulating dental plaque at the gingival margin contains lipoteichoic acids (LTAs) from the cell walls of gram-positive bacteria. In subgingival plaque associated with periodontal disease the amount of lipopolysaccharides (LPSs) from gram-negative bacteria increases. As the gingival junctional epithelium (JE) is an important structural and functional tissue, participating in the first line defence against apical advancement of dental plaque, this study examined the direct effects of LTAs (from Streptococcus mutans and S. sanguis) and LPSs (from Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Treponema denticola and Escherichia coli) on two epithelial cell lines (HaCaT and ERM) and a culture model for human JE. The cells were exposed to the LTAs or LPSs (10-50 microg/ml) for variable periods of time. None of the bacterial surface components had any effect on primary adhesion or on the epithelial attachment of the JE cultures. However, cell growth and mitotic activity were consistently reduced in all cultures treated with LTAs. In contrast, LPSs showed only slight or no effects on cell growth and mitotic activity depending on the epithelial cells used. This suggests that LPSs, despite their established role as modulators of inflammation, do not have direct harmful effects - at the concentrations found in dental plaque and gingival crevicular fluid - which would explain the mechanism of epithelial degeneration and detachment from the tooth surface. However, the LTAs appear to inhibit the renewal of epithelium and may thus contribute to degeneration of coronal JE and subgingival colonisation by periodontal pathogens. <17> UI - 20132574 AU - Shu M AU - Wong L AU - Miller JH AU - Sissons CH IN - Department of Pathology and Molecular Medicine, Wellington School of Medicine, University of Otago, New Zealand. TI - Development of multi-species consortia biofilms of oral bacteria as an enamel and root caries model system. SO - Archives of Oral Biology 2000 Jan;45(1):27-40 AB - The aim was to establish defined-species consortium plaque biofilms to investigate enamel and root caries in an artificial mouth. Strains of the putative enamel and root caries pathogens, Streptococcus mutans, Strep. sobrinus, Actinomyces naeslundii and Lactobacillus rhamnosus, were screened in batch culture for potential cariogenic properties: a low terminal pH, ability to aggregate, and catabolic diversity. The strains selected were grown as monoculture biofilms and as consortium plaque biofilms in a multiplaque artificial mouth. The biofilms were supplied with a constant flow of a simulated oral fluid and were given periodic sucrose (and in some instances glucose) to simulate meals. All the bacteria except L. rhamnosus formed large, monospecies biofilms with resting pH in the range 5.3-5.8. The consortia biofilms were larger and had a resting pH of 4.9-5.3. The consortia biofilms supplied with 8-hourly carbohydrate comprised mainly 'mutans' streptococci (58, SD 5.5%) and L. rhamnosus (42, SD 5.7%). A. naeslundii characteristically was absent or present in a low percentage (up to 4% colony-forming units). All biofilms demineralized polished bovine enamel and dentine blocks, as assessed by microradiography and enamel-surface microhardness measurement. The consortia also demineralized intact enamel and tooth roots; they were more cariogenic to enamel than any of the monoculture biofilms, as measured by enamel-surface softening, but variation in lesion depth was proportional to biofilm wet weight irrespective of acidogen composition (r = 0.93, p < 0.05). Enamel lesions had a well-mineralized intact surface and a zone of subsurface demineralization, typical of early natural lesions. Dentine and root lesions showed extensive demineralization but lacked a pronounced surface mineralized zone. Substitution of glucose for sucrose had no effect on the cariogenicity of the consortium to bovine enamel or human roots and had no major effect on the plaque composition. Continuously supplied fluoride (19 parts/10(6)) resulted in a substantially reduced enamel surface softening and subsurface demineralization of intact roots. It was concluded that consortia biofilms of selected caries pathogens generate realistic caries lesions in all tooth hard tissues under controlled growth conditions in the artificial mouth. This in vitro caries experimental model may prove useful for the study of interrelations between the plaque biofilm, tooth tissues and the oral environment, and for the development of procedures to modify the course of caries development. <18> UI - 20137424 AU - Cugini MA AU - Haffajee AD AU - Smith C AU - Kent RL Jr AU - Socransky SS IN - Department of Periodontology, The Forsyth Institute, Boston, MA, USA. TI - The effect of scaling and root planing on the clinical and microbiological parameters of periodontal diseases: 12-month results. SO - Journal of Clinical Periodontology 2000 Jan;27(1):30-6 AB - BACKGROUND/AIMS: Previously, we reported that SRP resulted in a decrease in mean pocket depth and attachment level and reduced prevalence and levels of Bacteroidesforsythus, Porphyromonas gingivalis, and Treponema denticola at 3 and 6 months post-SRP in 57 subjects with adult periodontitis. 32 of the 57 subjects were monitored at 9 and 12 months. Thus, the purpose of the present investigation was to evaluate the microbial and clinical effects of SRP in 32 (mean age 48+/-11) subjects over a 12-month period. METHOD: Clinical assessments of plaque, gingival redness, suppuration, bleeding on probing, pocket depth and attachment level were made prior to SRP and at 3, 6, 9, and 12 months post-therapy. Subgingival plaque samples were taken at each visit and analyzed using the checkerboard DNA-DNA hybridization technique for the presence and levels of 40 subgingival species. Each subject also received maintenance scaling at each of the subsequent monitoring visits. Differences in clinical parameters and prevalence and levels of bacterial species were analyzed pre- and post-therapy using the Wilcoxon signed ranks test. The Quade test for related samples was used for analysis of multiple visits. RESULTS: Mean pocket depth (mm+/-SEM) decreased from 3.2+/-0.3 at baseline to 2.9+/-0.3 at 12 months (p<0.01). Mean attachment level showed significant reduction at 6 months, but did not diminish further. Bleeding on probing and plaque were significantly reduced at 12 months (p<0.001, p<0.05, respectively). P. gingivalis, B. forsythus and T. denticola decreased in prevalence and levels up to the 6-month visit and remained at these lower levels at 9 and 12 months. Significant increases in levels and prevalence were noted at 12 months for Actinomyces naeslundii genospecies 2, Actinomyces odontolyticus, Fusobacterium nucleatum ss polymorphum, Streptococcus mitis, Capnocytophaga sp, and Veillonella parvula. CONCLUSIONS: The data suggest that the maintenance phase of therapy may be essential in consolidating clinical and microbiological improvements achieved as a result of initial therapy. <19> UI - 20108276 AU - Packer S AU - Woodley N AU - Wilson M AU - Mullany P IN - Department of Microbiology, Eastman Dental Institute for Oral Health Care Sciences, University College London, Great Britain. TI - Prevalence and persistence of amoxycillin-resistant bacteria in the dental plaques of adults. SO - Microbios 1999;100(397):135-44 AB - The prevalence and persistence of amoxycillin-resistant organisms (ARO) in the dental plaque of adults was determined. Plaque samples from ten adults, who had not taken antibiotics during the previous 6 months, were screened for ARO on three occasions at intervals of 3 months. The ARO were tested for their susceptibility to amoxycillin and to amoxycillin plus clavulanic acid as well as their ability to produce beta-lactamases. The ARO were found in all subjects on at least one sampling occasion and in 87% of the 30 samples examined. Of the 36 ARO isolated, 33% were yeasts, 19% were staphylococci, 19% Actinomycetes spp. and 14% lactobacilli, whilst seventeen of the isolates produced a beta-lactamase and seven of these were sensitive to coamoxiclav. The proportion of ARO in an individual fluctuated widely over the study period. It is suggested that the ARO are frequently, though transiently, present in low numbers in the plaque of individuals who have not recently received antibiotics. <20> UI - 20096384 AU - Jiang Y AU - Graves DT IN - Department of Endodontics, Boston University School of Dental Medicine, MA, USA. yljiang@acs.bu.edu TI - Periodontal pathogens stimulate CC-chemokine production by mononuclear and bone-derived cells. SO - Journal of Periodontology 1999 Dec;70(12):1472-8 AB - BACKGROUND: Chemokines are chemotactic cytokines that stimulate recruitment of leukocytes. Monocyte chemoattractant protein-1, macrophage inflammatory protein-1alpha, and RANTES (regulated on activation, normal T cell expressed, and secreted) are 3 well-characterized CC-chemokines that regulate mononuclear cell recruitment. The recruitment of inflammatory cells is of particular importance in the oral cavity because of the likelihood that cells will be challenged with bacteria either during acute infection or following surgical procedures. Porphyromonas gingivalis and Actinobacillus actinomycetemcomitans are putative periodontal pathogens that may be harbored in subgingival and supragingival plaque. The capacity of the host to respond to these bacteria by the elaboration of chemoattractants may represent an important defense mechanism. METHODS: In the present study, we examined CC-chemokine production by human mononuclear cells and bone-derived cells in response to P. gingivalis, A. actinomycetemcomitans and lipopolysaccharides (LPS) stimulation in vitro. The chemokines produced were measured by ELISA. RESULTS: The results demonstrate that P. gingivalis and A. actinomycetemcomitans induce high levels of MIP-1alpha in mononuclear cells. P. gingivalis and A. actinomycetemcomitans stimulated high levels of MCP-1 in bone-derived cells and induced moderate levels of RANTES production in both mononuclear and osteoblastic cells. In mononuclear cells, LPS induced high levels of MIP-1alpha and RANTES and moderate levels of MCP-1; in osteoblasts LPS only induced MCP-1. CONCLUSIONS: The capacity of bacteria to induce a given chemokine depends upon the cell type stimulated. That different cell types would exhibit differences in the CC-chemokines produced under the same stimulus provides a mechanism to explain tissue-specific recruitment of leukocytes. <21> UI - 20096381 AU - Celenligil-Nazliel H AU - Kansu E AU - Ebersole JL IN - Department of Periodontology, Faculty of Dentistry, Hacettepe University, Ankara, Turkey. TI - Periodontal findings and systemic antibody responses to oral microorganisms in Behcet's disease. SO - Journal of Periodontology 1999 Dec;70(12):1449-56 AB - BACKGROUND: Behcet's disease is a multisystem disorder of unknown etiology, affecting predominantly the oral mucosa, skin, and eyes. Recurrent and painful episodes of oral ulcerations interfere with regular oral hygiene leading to rapid bacterial plaque accumulation. The aims of this study were to evaluate the periodontal status of patients with Behcet's disease and determine serum antibody responses to selected oral microorganisms, including major periodontopathogens in these patients. METHODS: Thirty-three patients with Behcet's disease and 15 healthy subjects were included in the study. Plaque, sulcular bleeding, periodontal index scores, probing depths, and total number of teeth were recorded. Serum IgG antibody levels to a panel of 13 oral microorganisms were determined. RESULTS: Significantly higher values for each of the clinical measures were observed in patients with Behcet's disease compared to healthy subjects (P <0.0001). Antibody levels to selected members of plaque, including Actinomyces viscosus, Streptococcus mutans, Streptococcus sanguis, Streptococcus oralis, Eikenella corrodens, Campylobacter rectus, and Prevotella intermedia were significantly lower in patients with Behcet's disease than in controls (P <0.001-0.05). In contrast, these patients exhibited significantly elevated antibody levels to Actinobacillus actinomycetemcomitans Y4 compared to controls (P <0.01). CONCLUSIONS: Our data indicate that the patients with Behcet's disease generally exhibit clinical findings of established periodontal disease. Decreased antibody responses to early colonizers of both supra- and subgingival plaque were observed along with the elevation in antibody levels to A. actinomycetemcomitans. These results suggest that the bacterial plaque ecology and/or immune responses to these microorganisms may be affected in Behcet's disease which could lead to changes in the expression of periodontal disease. <22> UI - 20098051 AU - Takahashi N AU - Yamada T IN - Department of Oral Biochemistry, Tohoku University School of Dentistry, Sendai, Japan. TI - Glucose and lactate metabolism by Actinomyces naeslundii. [Review] [129 refs] SO - Critical Reviews in Oral Biology & Medicine 1999;10(4):487-503 AB - Actinomyces are among the predominant bacteria in the oral microflora. This review discusses the glucose and lactate metabolism of Actinomyces naeslundii and its ecological significance in dental plaque. This bacterium has the Embden-Meyerhof-Parnas (EMP) pathway as the main route to degrade glucose. The EMP pathway-derived metabolic intermediates, phosphoenolpyruvate (PEP) and pyruvate, are further converted into different end-products, depending on the environment. Under anaerobic conditions in the absence of bicarbonate, the pyruvate is converted into lactate by a lactate dehydrogenase. In the presence of bicarbonate, the PEP is combined with bicarbonate and then converted into succinate through the succinate pathway, while the pyruvate is converted into formate and acetate through the pyruvate formate-lyase pathway. Under aerobic conditions, the pyruvate liberates acetate and CO2 through a pathway initiated by a pyruvate dehydrogenase. A. naeslundii strains also degrade lactate, aerobically, to acetate and CO2 through the conversion of lactate into pyruvate by a NAD-independent lactate dehydrogenase. These strains also synthesize glycogen from a glycolytic intermediate, glucose 6-phosphate. Besides atmospheric conditions and bicarbonate, the intracellular reduction-oxidation potential, carbohydrate concentration, and environmental pH also modulate the metabolism of A. naeslundii. Some of the phosphorylating enzymes involved in A. naeslundii metabolism--e.g., GTP/polyphosphate (PPn)-dependent glucokinase, pyrophosphate (PPi)-dependent phosphofructokinase, UDP-glucose pyrophosphorylase, and GDP/IDP-dependent PEP carboxykinase--are unique to A. naeslundii and have not been found in other oral bacteria. The utilization of PPn and PPi as phosphoryl donors, together with glycogen synthesis and lactate utilization, could contribute to the efficient energy metabolism found in A. naeslundii. Through this flexible and efficient metabolic capacity, A. naeslundii can adapt to fluctuating environments and compete with other bacteria in dental plaque. Further, this bacterium may modify the dental plaque environment and promote the microbial population shifts in dental plaque. [References: 129] <23> UI - 20066888 AU - Feres M AU - Haffajee AD AU - Goncalves C AU - Allard KA AU - Som S AU - Smith C AU - Goodson JM AU - Socransky SS IN - Department of Periodontology, Forsyth Dental Center, Boston, MA, USA. TI - Systemic doxycycline administration in the treatment of periodontal infections (II). Effect on antibiotic resistance of subgingival species. SO - Journal of Clinical Periodontology 1999 Dec;26(12):784-92 AB - The purpose of this investigation was to determine the proportion and prevalence of doxycycline resistant species in subgingival plaque samples taken during and after doxycycline administration. 20 subjects with adult periodontitis were randomly assigned to test (n = 10) or control groups (n = 10). Saliva samples as well as subgingival plaque samples taken from the distal surface of 6 posterior teeth were collected at baseline. All subjects received full mouth SRP and the test group systemic doxycycline at the dosage of 100 mg/day for 14 days. Saliva samples and plaque samples from the distal surface of 2 randomly selected teeth were taken at 3, 7 and 14 days during and after antibiotic administration. Control subjects were sampled at the same time points. Samples were anaerobically dispersed and serially diluted in PRAS Ringer's solution and plated on enriched Trypticase soy blood agar plates with or without 4 microg/ml doxycycline. After 7 days of anaerobic incubation, colonies were counted on both sets of plates. Microbial growth was washed from the doxycycline-containing media and the species identified using 40 DNA probes and checkerboard DNA-DNA hybridization. Differences in proportions of resistant species between test and control groups were tested for significance at each time point using the Mann Whitney test and over time within each group using the Quade test. The mean % (+/-SEM) of isolates resistant to 4 microg/ml doxycycline in the plaque samples of the test subjects increased from 6+/-2 to 48+/-9% during doxycycline administration, decreasing to 25+/-6% 2 weeks later and 9+/-2% at 90 days. In saliva, the % of resistant isolates rose from 13+/-1% to 81+/-10% during doxycycline administration falling to 46+/-8% 2 weeks later and 22+/-5% at 90 days. The % of resistant isolates did not change significantly in plaque or saliva samples of the control subjects at the same time points. For all subject visits combined, the most prevalent resistant species were: Streptococcus anginosus, Streptococcus oralis, Streptococcus intermedius, Streptococcus sanguis, Streptococcus mitis, Veillonella parvula, Actinomyces gerencseriae, Streptococcus constellatus, Actinomyces naeslundii genospecies 2, Streptococcus gordonii, Eikenella corrodens and Actinomyces naeslundii genospecies 1. Doxycycline resistant strains of these species were detected in both plaque and saliva samples prior to therapy and in the control group. Despite the finding of increased resistance, approximately 50% of the organisms present at periodontal sites at the end of 14 days of doxycycline administration tested sensitive to the agent. <24> UI - 20066887 AU - Feres M AU - Haffajee AD AU - Goncalves C AU - Allard KA AU - Som S AU - Smith C AU - Goodson JM AU - Socransky SS IN - Department of Periodontology, Forsyth Dental Center, Boston, MA, USA. TI - Systemic doxycycline administration in the treatment of periodontal infections (I). Effect on the subgingival microbiota. SO - Journal of Clinical Periodontology 1999 Dec;26(12):775-83 AB - Systemic doxycycline is one of the more common antimicrobial agents used in the treatment of periodontal infections and yet little is known of its effect on subgingival plaque composition during and after its administration. The purpose of the present investigation was to evaluate changes in subgingival plaque composition during and after 14 days of doxycycline administration. 20 subjects with adult periodontitis were randomly assigned to test (n = 10) and control (n = 10) groups. The subjects received full mouth clinical assessment of pocket depth, attachment level, BOP, gingival redness, suppuration and plaque accumulation at baseline and 90 days. All subjects received full mouth SRP at baseline and, additionally, the test group received 100 mg doxycycline daily for 14 days. Subgingival plaque samples were taken from the mesial surface of up to 28 teeth in each subject at baseline and 90 days. In addition, plaque samples were taken from 2 randomly selected teeth at 3, 7 and 14 days during and after antibiotic administration. Control subjects were sampled at the same time points. Counts of 40 subgingival species were determined using checkerboard DNA-DNA hybridization and fluorescent detection. Significance of differences between test and control groups was determined at each time point using the Mann Whitney test. Significance of changes over time within test and control groups was determined using the Quade test. A modest but significant reduction in mean pocket depth from baseline to 90 days occurred in both test and control groups. A significant decrease in the % of sites with gingival redness occurred in the test group. There were no significant differences in proportions between test and control groups for 33 of the test species at any time point. Test subjects exhibited lower proportions of 4 Actinomyces species and an increase in 3 Streptococcus species during antibiotic administration. After cessation of doxycycline, Actinomyces sp. increased while Streptococcus sp. returned to baseline proportions. The relationship between these 2 genera appeared to be reciprocal; an increase in one was accompanied by a decrease in the other. Periodontal pathogens including B. forsythus, P. gingivalis, T. denticola and A. actinomycetemcomitans were not significantly altered by oral administration of doxycycline using conventional therapeutic dosage. <25> UI - 20015518 AU - Bowden GH IN - Department of Oral Biology, University of Manitoba, Winnipeg, Canada. TI - Controlled environment model for accumulation of biofilms of oral bacteria. SO - Methods in Enzymology 1999;310:216-24 <26> UI - 20065968 AU - Bowden GH AU - Nolette N AU - Ryding H AU - Cleghorn BM IN - Department of Oral Biology, Faculty of Dentistry, University of Manitoba, Winnipeg, Canada. TI - The diversity and distribution of the predominant ribotypes of Actinomyces naeslundii genospecies 1 and 2 in samples from enamel and from healthy and carious root surfaces of teeth. SO - Journal of Dental Research 1999 Dec;78(12):1800-9 AB - The bacterial communities associated with root caries are highly diverse and undergo succession during lesion formation. Consequently, root caries is said to have a polymicrobic etiology, typified by variation in the predominant species among samples from different lesions. Despite the polymicrobic etiology, A. naeslundii genospecies 1 and 2 (previously A. viscosus) have consistently been shown to be associated with root caries in humans; they predominate in some lesions and have been suggested to play a significant role in the disease. Several genetic variants of A. naeslundii are known to be present among the oral A. naeslundii population of an individual. The current study was initiated to explore the possibility that a variant in these A. naeslundii populations had characteristics which made it best fitted to colonize or promote root-surface caries lesions. Using ribotyping to detect variants, we tested the hypothesis that 'a ribotype of A. naeslundii best fitted to the environment would be selected and predominate in the A. naeslundii population of lesions'. Samples of plaque from enamel, normal root surfaces, plaque overlying the lesion, and material from within the lesion were taken from nine patients with soft root caries. The flora from 14 lesions and 9 enamel sites was analyzed on selective and non-selective media, and A. naeslundii genospecies were identified by serology. We ribotyped 972 isolates, showing 54 different patterns. Between 6 and 20 ribotypes were isolated from eight of nine patients. In general, each site from a patient showed a similar distribution of ribotypes. These results do not support the hypothesis and suggest that any phenotypic characters that allow A. naeslundii genospecies 1 and 2 to colonize or contribute to the formation of root-caries lesions are common among strains identified by ribotyping. <27> UI - 99454836 AU - Tran SD AU - Rudney JD IN - Department of Oral Science, School of Dentistry, University of Minnesota, Minneapolis, Minnesota 55455, USA. TI - Improved multiplex PCR using conserved and species-specific 16S rRNA gene primers for simultaneous detection of Actinobacillus actinomycetemcomitans, Bacteroides forsythus, and Porphyromonas gingivalis. SO - Journal of Clinical Microbiology 1999 Nov;37(11):3504-8 AB - Among putative periodontal pathogens, Actinobacillus actinomycetemcomitans, Bacteroides forsythus, and Porphyromonas gingivalis are most convincingly implicated as etiological agents in periodontitis. Therefore, techniques for detection of those three species would be of value. We previously published a description of a multiplex PCR that detects A. actinomycetemcomitans and P. gingivalis. The present paper presents an improvement on that technique, which now allows more sensitive detection of all three periodontal pathogens. Sensitivity was determined by testing serial dilutions of A. actinomycetemcomitans, B. forsythus, and P. gingivalis cells. Primer specificity was tested against (i) all gene sequences from the GenBank-EMBL database, (ii) six A. actinomycetemcomitans, one B. forsythus, and four P. gingivalis strains, (iii) eight different species of oral bacteria, and (iv) supra- and subgingival plaque samples from 20 healthy subjects and subgingival plaque samples from 10 patients with periodontitis. The multiplex PCR had a detection limit of 10 A. actinomycetemcomitans, 10 P. gingivalis, and 100 B. forsythus cells. Specificity was confirmed by the fact that (i) none of our forward primers were homologous to the 16S rRNA genes of other oral species, (ii) amplicons of predicted size were detected for all A. actinomycetemcomitans, B. forsythus, and P. gingivalis strains tested, and (iii) no amplicons were detected for the eight other bacterial species. A. actinomycetemcomitans, B. forsythus, and P. gingivalis were detected in 6 of 20, 1 of 20, and 11 of 20 of supragingival plaque samples, respectively, and 4 of 20, 7 of 20, and 13 of 20 of subgingival plaque samples, respectively, from periodontally healthy subjects. Among patients with periodontitis, the organisms were detected in 7 of 10, 10 of 10, and 7 of 10 samples, respectively. The simultaneous detection of three periodontal pathogens is an advantage of this technique over conventional PCR assays. <28> UI - 20043058 AU - Dung SZ IN - Division of Periodontology, National Yang-Ming University, Taipei, Taiwan, ROC. TI - Effects of mutans streptococci, Actinomyces species and Porphyromonas gingivalis on collagen degradation. SO - Chung Hua i Hsueh Tsa Chih - Chinese Medical Journal 1999 Nov;62(11):764-74 AB - BACKGROUND: While Streptococcus mutans and Actinomyces spp are considered to be major pathogenic microorganisms of root caries, their roles in the degradation of organic matrix components of human root dentin need clarification. METHODS: Ten laboratory strains and 11 clinical isolates of mutans streptococci and Actinomyces species, and positive bacterial or purified enzyme controls (Porphyromonas gingivalis whole cell lysates, trypsin or clostridial collagenase) were used to establish the degradation of azocollagen (AC), insoluble type I collagen (IC) or human dentin collagen (DC) from dentin powder in two types of experiments investigating collagenolytic activity either during or after bacterial growth. Ultraviolet-irradiated dentin powder and gamma-irradiated IC were used to assess the collagenolytic activity of test strains during bacterial growth. AC, IC and acid-treated dentin powder were used to determine the collagenolytic activity of sonicated bacterial whole cells and cell-free culture supernatants recovered from test strains after growth. Hydroxyproline or spectrophotometric assays were used to analyze the level of degraded collagen. RESULTS: Data from this study showed that in contrast to the positive controls, none of the laboratory strains or clinical isolates elicited significant degradation of AC, IC or DC. CONCLUSIONS: Results indicated that mutans streptococci and Actinomyces species had no significant collagenolytic activity, but may be involved in the root caries process through other mechanisms. In addition, proteolytic enzymes from other oral bacteria such as Porphyromonas gingivalis or from host cells such as neutrophils may also participate in the pathogenesis of root caries. <29> UI - 20064431 AU - Kalykakis GK AU - Mojon P AU - Nisengard R AU - Spiekermann H AU - Zafiropoulos GG TI - Clinical and microbial findings on osseo-integrated implants; comparisons between partially dentate and edentulous subjects. SO - European Journal of Prosthodontics & Restorative Dentistry 1998 Dec;6(4):155-9 AB - Clinical and microbiological parameters in partially dentate and edentulous patients treated with oral implants were compared in this study. Twenty-four subjects including 9 males and 15 females, aged 33 to 70 were treated with 98 Branemark fixtures. Plaque index, gingival index, pocket depth, implant mobility and crevicular fluid flow rate were measured. Latex agglutination tests identified the presence of Actinobacillus Actinomycetem-comitans, Porphyromonas gingivalis and Prevotella intermedia. Partially dentate patients accumulated more plaque than edentulous patients (P = 0.05), whereas crevicular fluid flow rate was significantly higher (P < 0.001) in the partially dentate population. Porphyromonas gingivalis and Prevotella intermedia were more frequently detected (P < 0.01) in partially dentate patients. These results indicate that the presence of natural teeth alter clinical and microbiological parameters which could in turn affect the long term success rate of implants. <30> UI - 99451724 AU - Fives-Taylor PM AU - Meyer DH AU - Mintz KP AU - Brissette C IN - Department of Microbiology & Molecular Genetics, University of Vermont, Burlington, USA. TI - Virulence factors of Actinobacillus actinomycetemcomitans. [Review] [250 refs] SO - Periodontology 2000 1999 Jun;20:136-67 AB - A. actinomycetemcomitans has clearly adapted well to its environs; its armamentarium of virulence factors (Table 2) ensures its survival in the oral cavity and enables it to promote disease. Factors that promote A. actinomycetemcomitans colonization and persistence in the oral cavity include adhesins, bacteriocins, invasins and antibiotic resistance. It can interact with and adhere to all components of the oral cavity (the tooth surface, other oral bacteria, epithelial cells or the extracellular matrix). The adherence is mediated by a number of distinct adhesins that are elements of the cell surface (outer membrane proteins, vesicles, fimbriae or amorphous material). A. actinomycetemcomitans enhances its chance of colonization by producing actinobacillin, an antibiotic that is active against both streptococci and Actinomyces, primary colonizers of the tooth surface. The fact that A. actinomycetemcomitans resistance to tetracyclines, a drug often used in the treatment of periodontal disease, is on the rise is an added weapon. Periodontal pathogens or their pathogenic products must be able to pass through the epithelial cell barrier in order to reach and cause destruction to underlying tissues (the gingiva, cementum, periodontal ligament and alveolar bone). A. actinomycetemcomitans is able to elicit its own uptake into epithelial cells and its spread to adjacent cells by usurping normal epithelial cell function. A. actinomycetemcomitans may utilize these remarkable mechanisms for host cell infection and migration to deeper tissues. A. actinomycetemcomitans also orchestrates its own survival by elaborating factors that interfere with the host's defense system (such as factors that kill phagocytes and impair lymphocyte activity, inhibit phagocytosis and phagocyte chemotaxis or interfere with antibody production). Once the organisms are firmly established in the gingiva, the host responds to the bacterial onslaught, especially to the bacterial lipopolysaccharide, by a marked and continual inflammatory response, which results in the destruction of the periodontal tissues. A. actinomycetemcomitans has at least three individual factors that cause bone resorption (lipopolysaccharide, proteolysis-sensitive factor and GroEL), as well as a number of activities (collagenase, fibroblast cytotoxin, etc.) that elicit detrimental effects on connective tissue and the extracellular matrix. It is of considerable interest to know that A. actinomycetemcomitans possesses so many virulence factors but unfortunate that only a few have been extensively studied. If we hope to understand and eradicate this pathogen, it is critical that in-depth investigations into the biochemistry, genetic expression, regulation and mechanisms of action of these factors be initiated. [References: 250] <31> UI - 99451728 AU - Socransky SS AU - Haffajee AD AU - Ximenez-Fyvie LA AU - Feres M AU - Mager D IN - Department of Periodontology, Forsyth Dental Center, Boston, Massachusetts, USA. TI - Ecological considerations in the treatment of Actinobacillus actinomycetemcomitans and Porphyromonas gingivalis periodontal infections. [Review] [119 refs] SO - Periodontology 2000 1999 Jun;20:341-62 <32> UI - 99451701 AU - Dung TZ AU - Liu AH IN - Division of Periodontology, Yang-Ming University, Taipai, Taiwan. tony@mailsrv.ym.edu.tw TI - Molecular pathogenesis of root dentin caries. [Review] [96 refs] SO - Oral Diseases 1999 Apr;5(2):92-9 AB - Human dentin has a higher content of organic matrix and more non-ideal hydroxyapatite than human enamel. Ultrastructural studies indicate that root caries involves both mineral dissolution and breakdown of the organic matrix. Factors involved in the root caries process seem more complicated than those in enamel caries. Moreover, the distinct roles of acids and enzymes and the sequence of events in the root caries process are not well-understood. Although Streptococcus mutans and Actinomyces viscosus are considered to be major pathogenic micro-organisms of root caries, their roles in degradation of the organic matrix components of root dentin need clarification. The purpose of this paper is to review the basic composition of root dentin and the roles of acids and both endogenous and bacterial enzymes in the root caries process. [References: 96] <33> UI - 99440939 AU - Brailsford SR AU - Tregaskis RB AU - Leftwich HS AU - Beighton D IN - Joint Microbiology Research Unit, Dental Institute, King's College School of Medicine and Dentistry, London. TI - The predominant Actinomyces spp. isolated from infected dentin of active root caries lesions. SO - Journal of Dental Research 1999 Sep;78(9):1525-34 AB - Actinomyces are Gram-positive pleomorphic rods (GPPR) which form a large proportion of the oral microflora of all mammals. They have been implicated in root caries, although their role in dental caries initiation and progression is not well-understood. Many studies have focused on Actinomyces naeslundii, but few reports have documented other members of the GPPR. Therefore, we investigated the GPPRs isolated from infected dentin of active root caries lesions (n = 9) to determine which species were the most frequently isolated. The GPPR were isolated under both aerobic and anaerobic conditions and identified by biochemical and physiological tests to the species level according to the new taxonomy. Of 654 GPPR isolates investigated, 607 were identified as belonging to the genus Actinomyces. Of these, 242 were identified as A. israelii, 225 as A. gerencseriae, 109 as A. naeslundii, 15 as A. odontolyticus, and 13 as A. georgiae. Individual strains of A. israelii (n = 56) and A. gerencseriae (n = 46) were also investigated at the DNA level by means of Repetitive Extragenic Palindromic polymerase chain-reactions (REP-PCR) for the study of clonal diversity. Although only a small number of isolates was investigated, REP-PCR showed that the genotypes of both A. gerencseriae and A. israelii populations were heterogeneous within individual root caries lesions. A. gerencseriae and A. israelii strains from the same lesions did not share the same REP-PCR patterns, showing the robustness of the identification scheme. A significantly greater proportion of A. gerencseriae was isolated from the aerobic plates (p < 0.05), while the proportion of A. israelii was significantly (p < 0.05) greater from anaerobic plates. The role of individual Actinomyces spp. in the root caries process remains unclear, since various populations of GPPRs were isolated from individual active root caries lesions. <34> UI - 99440938 AU - Ehmke B AU - Schmidt H AU - Beikler T AU - Kopp C AU - Karch H AU - Klaiber B AU - Flemmig TF IN - Department of Periodontology, Julius Maximilians University of Wurzburg, Germany. TI - Clonal infection with Actinobacillus actinomycetemcomitans following periodontal therapy. SO - Journal of Dental Research 1999 Sep;78(9):1518-24 AB - Mechanical debridement results in a shift of the bacterial composition in the periodontal pocket on the species level. It is unknown, however, whether a clonal change within a species could lead to the emergence of strains with different levels of virulence. Therefore, in the present study, the genetic variability of Actinobacillus actinomycetemcomitans was assessed and strains identified which were associated with periodontal disease progression following periodontal therapy, i.e., refractory periodontitis. Twenty adult patients with untreated periodontitis and subgingival colonization of A. actinomycetemcomitans were randomly assigned to receive full-mouth scaling alone or scaling with an adjunctive antimicrobial therapy. Both groups received supportive periodontal therapy at 3, 6, 9, 12, 18, and 24 months. Subgingival plaque samples were taken at every visit; venous blood was obtained at 24 months only. A. actinomycetemcomitans isolates were typed by the RAPD method, and antibody reactivity against outer membrane proteins was assessed by immunoblot analysis. Eleven distinct RAPD patterns were found in 18 patients completing the study. All patients harbored only one A. actinomycetemcomitans genotype, and within each patient this genotype persisted throughout the 24-month observation period. No differences in the expression of antibody reactivity against outer membrane proteins were found between strains isolated at baseline and at 24 months. Three genotypes were associated with reduced survival rates of teeth without probing attachment loss of 2 mm or more. The results indicated that (i) most patients harbored only one A. actinomycetemcomitans genotype; (ii) the genotype persisted following therapy; and (iii) only some genotypes were associated with refractory periodontitis. <35> UI - 99386881 AU - Schenkein HA AU - Gunsolley JC AU - Best AM AU - Harrison MT AU - Hahn CL AU - Wu J AU - Tew JG IN - Clinical Research Center for Periodontal Disease, Virginia Commonwealth University, Richmond, Virginia 23298-0566, USA. hschenke@hsc.vcu.edu TI - Antiphosphorylcholine antibody levels are elevated in humans with periodontal diseases. SO - Infection & Immunity 1999 Sep;67(9):4814-8 AB - Human immunoglobulin G2 (IgG2) serum concentrations and the IgG2 antibody response to Actinobacillus actinomycetemcomitans can be influenced by genes, by environmental factors such as smoking, and by periodontal disease status. Examination of the IgG2 response to phosphorylcholine (PC), a response thought to be mainly induced by the C polysaccharide of Streptococcus pneumoniae, suggested that periodontal disease status was also associated with this response. This prompted the hypothesis that PC is an important oral antigen associated with organisms in the periodontal flora and that anti-PC antibody is elevated as a consequence of periodontal disease. Subjects in various periodontal disease diagnostic categories in which attachment loss is exhibited were tested for anti-PC in serum. Those with adult periodontitis, localized juvenile periodontitis, generalized early-onset periodontitis, and gingival recession all had similar levels of anti-PC IgG2 serum antibody which were significantly greater than in the group of subjects with no attachment loss. Analysis of plaque samples from subgingival and supragingival sites in all diseases categories for reactivity with the anti-PC specific monoclonal antibody TEPC-15 revealed that a substantial proportion of the bacteria in dental plaque (30 to 40%) bear PC antigen; this antigen was not restricted to morphotypes resembling only cocci but was also present on rods and branched filamentous organisms. We found that S. mitis, S. oralis, and S. sanguis, as well as oral actinomycetes, including A. viscosus, A. odontolyticus, and A. israelii, incorporated substantial amounts of [(3)H]choline from culture media. Further analysis of antigens derived from these organisms by Western blot indicated that S. oralis, S. sanguis, A. viscosus, A. odontolyticus, and A. israelii contained TEPC-15-reactive antigens. The data show that many commonly occurring bacterial species found in dental plaque contain PC antigen and that immunization with plaque-derived PC antigens as a consequence of inflammation and periodontal attachment loss may influence systemic anti-PC antibody concentrations. <36> UI - 99391683 AU - Beighton D AU - Brailsford SR AU - Lynch E AU - Chen HY AU - Clark DT IN - Joint Microbiology Research Unit, Guy's King's and St. Thomas' Dental Institute, Whitechapel, England. david.beighton@kcl.ac.uk TI - The influence of specific foods and oral hygiene on the microflora of fissures and smooth surfaces of molar teeth: A 5-day study. SO - Caries Research 1999 Sep-Oct;33(5):349-56 AB - A group of 20 students, harbouring >10(4) mutans streptococci per millilitre of saliva, was enrolled into the study. Models for sampling, reproducibly, the dental plaque present in specific sites (fissure and smooth surface) on the dentition were developed and validated. Withdrawal of normal oral hygiene procedures for only 1 day resulted in approximately 10-fold increases in the number of micro-organisms recovered from both sites. The effect of supplementing the subjects' diets with particular food items given 5 times per day [lemonade (5.8% w/v sugars, 250 ml), biscuits (digestive biscuits, 67.6% w/w carbohydrate of which 22% w/w was sugars and 45.6% w/w was starch), caramel toffees and sugar lumps] on the number of micro-organisms recovered and on the composition of the flora at both sites was determined. Dental plaque samples were taken after 5 days and it was found that supplementation of the diet with toffee and sugar lumps resulted in significantly more micro-organisms at both sampling sites. The supplementation of the diets with lemonade or biscuits did not significantly alter the numbers of micro-organisms recovered from either site. The percentage composition of the plaque samples from both dental sites remained relatively unaffected by oral hygiene although there were lower levels of mutans streptococci which might be related to the use of an antimicrobial toothpaste containing fluoride, triclosan and zinc citrate. This study suggests that the cariogenicity of certain sucrose-containing foods may, in part, be due to the enhancement of plaque accumulation in addition to other effects on the percentage composition of the plaque which may become manifest on prolonged usage of these dietary foodstuffs. These observations are consistent with dietary survey findings which often find consumption of confectionery related to caries experience or incidence. <37> UI - 99391684 AU - Gonzalez-Cabezas C AU - Li Y AU - Gregory RL AU - Stookey GK IN - Oral Health Research Institute, School of Dentistry and School of Medicine, Indiana University, Indianapolis, Ind. 46202, USA. CGONZALE@IUSD.IUPUI.EDU TI - Distribution of three cariogenic bacteria in secondary carious lesions around amalgam restorations. SO - Caries Research 1999 Sep-Oct;33(5):357-65 AB - Secondary dental caries remains an unresolved problem in dentistry and little is known of its microbial etiology. The purpose of this study was to compare the distribution of the three most suspected cariogenic groups of bacteria, mutans streptococci. Actinomyces naeslundii genospecies 2 and lactobacilli, in natural secondary caries around amalgam restorations. Extracted teeth with secondary caries were sectioned to obtain three samples that were randomly distributed to three different groups. Each group was immunolabeled with antibodies to either Streptococcus mutans, A. naeslundii genospecies 2 or Lactobacillus casei and subsequently labeled with secondary fluorescent antibodies. All samples were analyzed three-dimensionally using confocal microscopy. The results indicated that the three different bacteria were widely present and could have an important role in the development of secondary caries around amalgam restorations. <38> UI - 99415236 AU - Velazco CH AU - Coelho C AU - Salazar F AU - Contreras A AU - Slots J AU - Pacheco JJ IN - Department of Microbiology, Instituto Superior de Ciencias de Saude-Norte, Paredes, Portugal. TI - Microbiological features of Papillon-Lefevre syndrome periodontitis. SO - Journal of Clinical Periodontology 1999 Sep;26(9):622-7 AB - Papillon-Lefevre syndrome patients exhibit hyperkeratosis palmo-plantaris and severe periodontitis. The syndrome is an autosomal recessive trait, but the mechanism of periodontal destruction is not known. This report presents the clinical and microbiological features of an 11-year old girl with Papillon-Lefevre syndrome. Clinical examination included conventional periodontal measurements and radiographic analysis. In samples from 3 deep periodontal lesions, the occurrence of major suspected periodontopathic bacteria was determined by selective and non-selective culture and polymerase chain reaction (PCR) identification, and the presence of cytomegalovirus and Epstein-Barr type 1 virus by a nested-PCR detection method. 10 of 22 available teeth demonstrated severe periodontal breakdown. Major cultivable bacteria included Actinobacillus actinomycetemcomitans (3.4% of total isolates), Prevotella nigrescens (16.4%), Fusobacterium nucleatum (14.3%) and Peptostreptococcus micros (10.6%). A. actinomycetemcomitans, P. nigrescens, Porphyromonas gingivalis and Eikenella corrodens were identified by PCR analysis. The patient's non-affected parents and older brother revealed several periodontal pathogens but not A. actinomycetemcomitans. The viral examination demonstrated cytomegalovirus and Epstein-Barr type 1 virus in the subgingival sample of the Papillon-Lefevre syndrome patient. The father and brother yielded subgingival cytomegalovirus but not Epstein-Barr type 1 virus. We hypothesize that human herpesviruses in concert with A. actinomycetemcomitans play important roles in the development of Papillon-Lefevre syndrome periodontitis. <39> UI - 99404543 AU - Wong MY AU - Lu CL AU - Liu CM AU - Hou LT IN - School of Dentistry, College of Medicine, National Taiwan University, Taipei. veronica@ha.mc.ntu.edu.tw TI - Microbiological response of localized sites with recurrent periodontitis in maintenance patients treated with tetracycline fibers. SO - Journal of Periodontology 1999 Aug;70(8):861-8 AB - BACKGROUND: Whether adjunctive tetracycline fibers can provide an additive effect to scaling and root planing in treating non-responsive sites in maintenance subjects is still controversial. Recolonization of the bacteria from untreated sites or from the extracrevicular region may explain the insignificant response to local therapy. The purpose of the present study was to evaluate the microbiological response of sites treated with tetracycline fibers combined with scaling and root planing. METHODS: The study was conducted in a split-mouth design. Thirty patients on maintenance therapy having at least 2 non-adjacent sites in separate quadrants with probing depths between 4 to 8 mm with bleeding on probing, or aspartate aminotransferase enzyme levels > 800 microIU in the gingival crevicular fluid, were treated with scaling and root planing plus tetracycline fibers or with scaling and root planing only. Subgingival plaque samples were collected at baseline, and 1, 3, and 6 months following treatment. A. actino-mycetemcomitans, C. rectus, B. forsythus, E. corrodens, F. nucleatum, P. gingivalis, and P. intermedia were detected by culture, immunofluorescence, or PCR technique. RESULTS: There was a reduction of total bacterial cell count, as well as of certain periodontal pathogens, following treatment. The prevalence of A. actinomycetemcomitans, B. forsythus, and P. gingivalis and the mean proportions of C. rectus, P. intermedia, F. nucleatum, and P. gingivalis decreased after therapy, but there was no statistically significant difference between the 2 treatment groups with respect to bacterial proportions or the number of positive sites. Besides, the pathogens could not be eliminated from the periodontal pocket, and recolonization of the pocket was noted at 3 months post-treatment. CONCLUSIONS: Bacteria located within the cheek, tongue mucosa, saliva, or untreated sites may contribute to reinfection of the pockets and explain the insignificant response to local tetracycline therapy. <40> UI - 99367254 AU - Scannapieco FA IN - Department of Oral Biology, University at Buffalo, State University of New York, USA. TI - Role of oral bacteria in respiratory infection. [Review] [87 refs] SO - Journal of Periodontology 1999 Jul;70(7):793-802 AB - An association between oral conditions such as periodontal disease and several respiratory conditions has been noted. For example, recent evidence has suggested a central role for the oral cavity in the process of respiratory infection. Oral periodontopathic bacteria can be aspirated into the lung to cause aspiration pneumonia. The teeth may also serve as a reservoir for respiratory pathogen colonization and subsequent nosocomial pneumonia. Typical respiratory pathogens have been shown to colonize the dental plaque of hospitalized intensive care and nursing home patients. Once established in the mouth, these pathogens may be aspirated into the lung to cause infection. Other epidemiologic studies have noted a relationship between poor oral hygiene or periodontal bone loss and chronic obstructive pulmonary disease. Several mechanisms are proposed to explain the potential role of oral bacteria in the pathogenesis of respiratory infection: 1. aspiration of oral pathogens (such as Porphyromonas gingivalis, Actinobacillus actinomycetemcomitans, etc.) into the lung to cause infection; 2. periodontal disease-associated enzymes in saliva may modify mucosal surfaces to promote adhesion and colonization by respiratory pathogens, which are then aspirated into the lung; 3. periodontal disease-associated enzymes may destroy salivary pellicles on pathogenic bacteria to hinder their clearance from the mucosal surface; and 4. cytokines originating from periodontal tissues may alter respiratory epithelium to promote infection by respiratory pathogens. [References: 87] <41> UI - 99349166 AU - Saini S AU - Mahajan A AU - Sharma JK AU - Arora AU - Saini OP IN - Department of Microbiology and Dental College and Hospital, Pt. B.D. Sharma PGIMS, Rohtak, Haryana. TI - Polymicrobial etiology of dental caries. SO - Indian Journal of Pathology & Microbiology 1999 Jan;42(1):25-9 AB - The present study was carried out to establish the normal bacterial oral flora and the aerobic and anaerobic bacterial flora from deep seated dental caries, and to determine the antimicrobial sensitivity of the clinical isolates so obtained Streptococcus mutans (48%) and Streptococcus sanguis (20%) were the main aerobic isolates whereas Lactobacillus spp. (52%), Veillonella spp. (24%) and Actinomyces spp. (12%) were the major anaerobic isolates. Hundred percent of the samples from dental caries yielded polymicrobial isolates while in two samples from healthy individuals S. mutans was the sole isolate. As the flora changed from healthy tooth to dental caries it changed from one predominated by anaerobic gram-positive cocci to anaerobic gram-positive bacilli. All the anaerobes isolated were sensitive to metronidazole and cefotaxime, whereas all the isolated streptococci were sensitive to penicillin, erythromycin and clindamycin. Incorporation of the antibiotics in baseline restoration, if technically feasible, has been advocated. <42> UI - 99316508 AU - Eick S AU - Pfister W AU - Straube E IN - Department of Medical Microbiology, University Hospital of Jena, Germany. eick@bach.med.uni-jena.de TI - Antimicrobial susceptibility of anaerobic and capnophilic bacteria isolated from odontogenic abscesses and rapidly progressive periodontitis. SO - International Journal of Antimicrobial Agents 1999 Jun;12(1):41-6 AB - In dentistry antimicrobials are used in the treatment of progressive periodontitis and odontogenic abscesses, therefore the susceptibility to commonly used antibiotics of capnophilic and anaerobic species causing these diseases should be investigated. The activity of penicillin, amoxycillin, cefoxitin, clindamycin, doxycycline, metronidazole and ciprofloxacin was investigated. One hundred and sixty four isolates from subgingival plaque samples of 66 patients with progressive periodontitis and 192 bacterial strains from pus of 74 patients with odontogenic abscesses were included in this study. The majority of species tested were gram-negative anaerobes (Prevotella spp., Porphyromonas spp., Fusobacterium spp.), and were highly susceptible to clindamycin and metronidazole. Nearly 6% of the periodontal isolates and 22% of the bacteria obtained from pus samples produced beta-lactamases. With the exception of the periodontopathogenic species Actinobacillus actinomycetemcomitans and Eikenella corrodens, clindamycin seemed to be a useful antibiotic and could be recommended for empirical antimicrobial treatment. <43> UI - 99352539 AU - Piccolomini R AU - Catamo G AU - Di Placido G AU - D'Ercole S AU - Tumini V AU - Picciani C AU - Paolantonio M IN - Dipartimento di Scienze Biomediche, Universita degli Studi G. d'Annunzio, Chieti, Italy. TI - Bacteriological and clinical follow-up of periodontal pockets during a topically applied 1% metronidazole-gel therapy in patients with adult periodontitis. SO - New Microbiologica 1999 Jul;22(3):219-25 AB - The aim of this study was to evaluate the clinical and bacteriological effects of the intrasulcular application of a 1% metronidazole-gel (repeated administrations outdistanced of 7 days weeks long) currently employed in dermatological practice, to observe if a lower concentration of the chemotherapic agent could be equally effective as the 25% formulation in improving the periodontal condition of nine patients with adult periodontitis. The results showed that this regimen can modify, at a statistically significant level, the clinical (Pocket Probing Depth, Gingival Bleeding Index and Plaque Index) and bacteriological (Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia and Veillonella parvula) parameters associated with adult periodontitis. The results are similar to those obtainable with a 25% Metronidazole-gel administered two times outdistanced by 7 days. <44> UI - 99352538 AU - Lo Bue AM AU - Nicoletti G AU - Toscano MA AU - Rossetti B AU - Cali G AU - Condorelli F IN - Institute of Microbiology, University of Catania, Italy. TI - Porphyromonas gingivalis prevalence related to other micro-organisms in adult refractory periodontitis. SO - New Microbiologica 1999 Jul;22(3):209-18 AB - Forty-six adult periodontal patients, selected on the basis of clinical examination, and 46 adult healthy subjects were examined. The subgingival plaque samples from one inflammatory and one non-inflammatory site of each periodontal patient were studied to determine Porphyromonas gingivalis prevalence related to other periodontal micro-organisms and to periodontal tissue destruction. The results showed Porphyromonas gingivalis as the main pathogenic micro-organism isolated in the inflammatory sites together with Bacteroides forsythus. Peptostreptococcus sp., Actinomyces sp. and Prevotella sp. were found as a normal oral flora in the healthy subjects. Fusobacterium nucleatum, Prevotella intermedia, Campylobacter rectus and Eikenella corrodens were detected both in inflammatory and in non-inflammatory sites of periodontal patients as well as in the healthy subjects. <45> UI - 99351674 AU - Gmur R AU - Marinello CP AU - Guggenheim B IN - Institute of Oral Microbiology and General Immunology, University of Zurich, Switzerland. gmuer@zzmk.unizh.ch TI - Periodontitis associated bacteria in supragingival plaque of dental hygienists: stability of carrier state and clinical development. SO - European Journal of Oral Sciences 1999 Jun;107(3):225-8 AB - The purpose of this study was the clinical and microbiological re-examination of dental hygienists, who, 30 months before, had shown remarkably high supragingival levels of periodontitis-associated micro-organisms. Interdental plaque was collected from the same molar sites and investigated by the same immunofluorescence assay with taxa-specific monoclonal antibodies as at the initial examination. On average, the 15 re-examined subjects showed slightly increased plaque levels but unchanged bleeding on probing scores (0.3-1.4). Pocket formation was restricted to a single subject. Prevotella intermedia/P. nigrescens and Peptostreptococcus micros were present in every plaque sample. Prevalences of Actinobacillus actinomycetemcomitans, Bacteroides forsythus and Campylobacter rectus were again between 20-40%, but some fluctuation within subjects was noted. The data confirm supragingival plaque as a natural habitat for periodontitis-associated bacteria in periodontially healthy persons, and indicate that colonization with A. actinomycetemcomitans, B. forsythus or C. rectus is mostly stable in spite of better than average personal plaque control. <46> UI - 99378019 AU - Mombelli A AU - Gmur R AU - Lang NP AU - Corbert E AU - Frey J IN - School of Dental Medicine, University of Bern, Switzerland. andrea.mombelli@medecine.unige.ch TI - Actinobacillus actinomycetemcomitans in Chinese adults. Serotype distribution and analysis of the leukotoxin gene promoter locus. SO - Journal of Clinical Periodontology 1999 Aug;26(8):505-10 AB - The aim of the present study was to examine the Actinobacillus actinomycetemcomitans carrier rate in Chinese subjects, and to determine serotype distribution, presence of the leukotoxin gene lktA and the structure of the lktA-promoter region. Subgingival microbiological samples were obtained from 31 Chinese subjects with moderate to advanced adult periodontitis, 73 young factory workers, and 81 adult residents of a rural area. Bacterial isolates phenotypically identified as A. actinomycetemcomitans were found in 116 of the 185 subjects (detection frequency over-all: 63%). Presence of the leukotoxin gene lktA was demonstrated for all 115 isolates that could be subcultured. The PCR analysis of the lktA-promoter region showed that none of these strains had the deletion in the promoter region known to enhance expression of lktA. No significant difference in the frequency of A. actinomycetemcomitans could be observed between the subjects of the 3 study groups. Analysis by logistic multiple regression indicated a homogeneous distribution of A. actinomycetemcomitans in the 3 cohorts and a lack of significant influence of subject gender or age. Serotype a was found in 21 subjects, serotype b was found in 9, serotype c in 67 and serotype e in 11 individuals. Serotype d was not detected in any subject. Nontypeable isolates, lacking serotype a, b, c, d, or e antigens, were found in 9 individuals. A high prevalence irrespective of gender, age, and cohort suggests that A. actinomycetemcomitans is a common constituent of the normal flora in the Chinese subjects of this study and suggests differences in the microbiological composition of subgingival plaque may exist for this population group as compared to north American and European populations. <47> UI - 99339196 AU - Winkel EG AU - van Winkelhoff AJ AU - Barendregt DS AU - van der Weijden GA AU - Timmerman MF AU - van der Velden U IN - Department of Periodontology, Academic Centre for Dentistry Amsterdam, The Netherlands. TI - Clinical and microbiological effects of initial periodontal therapy in conjunction with amoxicillin and clavulanic acid in patients with adult periodontitis. A randomised double-blind, placebo-controlled study. SO - Journal of Clinical Periodontology 1999 Jul;26(7):461-8 AB - The aim of the present study was to investigate the clinical and microbiological effects of initial periodontal therapy in conjunction with systemic amoxicillin plus clavulanic acid in adult periodontitis patients using a double-blind, parallel-group, and placebo-controlled protocol. 21 patients with a clinical diagnosis of generalised adult periodontitis were recruited. Clinical measurements and microbiological assessments were carried out at baseline, 3, and 12 months post-treatment. Approximately 6 weeks after initial periodontal treatment (3-6 h), patients were randomly assigned to receive coded study medication of 500 mg amoxicillin plus 125 mg clavulanic acid (Augmentin) or placebo, every 8 h for 10 days. Patients returned for follow-up visits 3, 6, 9, and 12 months after completion of the medication. The mean plaque index (PI) at baseline was 1.1 for placebo group and 0.9 for the test group. At 3 months, the PI had dropped to 0.3 in both groups, and was maintained during the rest of the study. The changes in bleeding on probing (BOP) and gingival index (GI) in the course of the study were similar in both groups. The mean whole mouth probing pocket depth (PPD) in the placebo group was 3.8 mm at baseline and 3.9 mm in the test group. A mean reduction of 1.0 mm in the placebo group and 0.9 mm in the test group was observed during the first 3 months. No further reduction in PPD was noticed during the study period in either group. There was no statistically significant difference in the PPD reduction between the 2 groups. The change in clinical attachment level (CAL) from baseline to 3 months amounted to 0.5 mm in both groups. Between 3 and 12 months, the CAL changed in neither group. In both groups, treatment resulted in a decrease in the number of spirochetes and motile rods in positive patients, but no significant differences between either group were noted in any of the dark field microscopy observations. At baseline, 1 patient in the placebo group and 2 patients in the test group were culture positive for Actinobacillus actinomycetemcomitans (Aa). After therapy, Aa was not detectable in the placebo group and 1 patient remained positive in the test group. In the placebo group, the number of patients positive for Porphyromonas gingivalis (Pg) decreased from 7 to 2 after therapy. In the test group, the 4 patients positive for Pg at baseline remained positive after therapy. In both groups, all subjects were positive for Prevotella intermedia (Pi) and Fusobacterium nucleatum (Fn) at baseline. At 12 months, all subjects had detectable subgingival Fn. 9 out of the 11 placebo and 8 of the 10 test patients remained positive for Pi. There were no differences in detection frequency of Peptostreptococcus micros (Pm) and Bacteroides forsythus (Bf) in both groups between baseline, 3, and 12 months post-treatment. The findings demonstrated that, in comparison to placebo, systemic amoxicillin plus clavulanic acid provided no additional clinical and microbiological effects in the treatment of adult periodontitis patients. <48> UI - 99318584 AU - Pratten J AU - Wilson M IN - Department of Microbiology, Eastman Dental Institute for Oral Health Care Sciences, University College London, London, WC1X 8LD, United Kingdom. jpratten@eastman.ucl.ac.uk TI - Antimicrobial susceptibility and composition of microcosm dental plaques supplemented with sucrose. SO - Antimicrobial Agents & Chemotherapy 1999 Jul;43(7):1595-9 AB - The aims of this study were to evaluate the effects of repeated chlorhexidine gluconate (CHG) pulsing on the viability and bacterial composition of microcosm dental plaques derived from human saliva. The biofilms were grown on bovine enamel discs in a constant-depth film fermentor fed with an artificial saliva which was supplemented thrice daily with sucrose. The microcosm plaques had total viable anaerobic counts of 5 x 10(8) CFU per mm2 and consisted of 12% Actinomyces spp., 85% streptococci, and 0.2% Veillonella spp. When pulsed twice daily with 0.2% CHG, there was an immediate 1.3-log10 reduction in the total viable (anaerobic) count. However, as pulsing continued, the viable counts recovered, and after 4 days, the anaerobic count reached its pre-CHG-pulsing level, although the bacterial composition of the biofilms had changed. The results of this study show that twice-daily pulsing with 0.2% CHG over a 4-day period was ineffective at reducing the total anaerobic viable count of the biofilms but did alter their bacterial composition. <49> UI - 99255920 AU - Piccolomini R AU - Di Bonaventura G AU - Catamo G AU - Tumini V AU - Di Placido G AU - D'Ercole S AU - Perfetti G AU - Paolantonio M IN - Dipartimento di Scienze Biomediche, Universita degli Studi G. d'Annunzio, Chieti, Italy. TI - Microbiological and clinical effects of a 1% chlorhexidine-gel in untreated periodontal pockets from adult periodontitis patients. SO - New Microbiologica 1999 Apr;22(2):111-6 AB - The aim of this study was to report the microbiological and clinical effects of repeated subgingival administration of a 1% Chlorhexidine-gel in periodontal pockets from 10 patients with adult periodontitis. Results showed that the experimental treatment significantly improved clinical parameters (Plaque Index, Gingival Bleeding Index, and Pocket Probing Depth). Direct subgingival administration of Chlorhexidine-gel also produced a remarkable modification in the proportions of putative periodontopathic microorganisms, such as Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, Veillonella parvula, Fusobacterium nucleatum, and Peptostreptococcus micros, in subgingival bacterial plaque from periodontitis patients. <50> UI - 99297658 AU - Helmerhorst EJ AU - Hodgson R AU - van 't Hof W AU - Veerman EC AU - Allison C AU - Nieuw Amerongen AV IN - Academic Centre for Dentistry (ACTA), Vrije Universiteit, Department of Oral Biochemistry, The Netherlands. TI - The effects of histatin-derived basic antimicrobial peptides on oral biofilms. SO - Journal of Dental Research 1999 Jun;78(6):1245-50 AB - Susceptibility of bacteria to antimicrobial agents is strongly reduced by the formation of complex biofilms. We investigated whether synthetic histatin analogs with broad-spectrum antibacterial activity in vitro were also active against these complex mixtures of bacteria, as present in saliva and plaque. In a simplified model system for dental plaque, hydroxyapatite discs were placed in a continuous culture system comprised of Streptococcus mutans, S. sanguis, S. salivarius, Actinomyces naeslundii, Veillonella parvula, Fusobacterium nucleatum, and Prevotella intermedia. Ex situ treatment of the biofilms formed on these discs with 100 microg/mL of peptide dhvar4 significantly reduced facultative anaerobic, total anaerobic, and obligate anaerobic Gram-negative counts with 0.8, 0.5, and 0.5 log units, respectively. Ex vivo treatment of salivary bacteria gave reductions of 0.4, 0.7, and 1.5 log units, respectively. For ex vivo treatment of plaque bacteria, reductions of 0.4, 0.4, and 1.4 log units, respectively, were found. In both saliva and plaque samples, obligate anaerobic Gram-negative bacteria were significantly more susceptible to dhvar4 than facultatively anaerobic or anaerobic bacteria as a whole (p=0.013 and p=0.018, for salivary bacteria, and p=0.021 and p=0.020 for plaque bacteria, respectively). Although the oral bacteria are protected by biofilm formation, the synthetic histatin analog caused a significant reduction of viable counts in a model for oral biofilm as well as in isolated oral biofilms. <51> UI - 99247415 AU - Agholme MB AU - Dahllof G AU - Modeer T IN - Department of Pediatric Dentistry, School of Dentistry, Karolinska Institutet, Huddinge, Sweden. Monica.Barr.Agholme@ofa.ki.se TI - Changes of periodontal status in patients with Down syndrome during a 7-year period. SO - European Journal of Oral Sciences 1999 Apr;107(2):82-8 AB - The development of periodontal disease in Down syndrome adolescents (n = 34) was studied clinically and on intraoral radiographs during a 7-yr period. The occurrence of gingival inflammation (GBI), pathological periodontal pockets (>4 mm), sub- and supragingival calculus, alveolar bone height, alveolar bone loss, and the occurrence of the periodontal pathogens Actinobacillus actinomycetemcomitans, Capnocytophaga, and Porphyromonas gingivalis in subgingival plaque were determined. Of the subjects, 41% had one or more pathological periodontal pockets at baseline compared to 65% at follow-up. At the baseline examination, 35% of the individuals exhibited alveolar bone loss compared to 74% at the follow-up. The median value of sites with alveolar bone loss increased from 0 to 1, the new lesions mainly being located in the incisor region. The estimated annual reduction of alveolar bone height in each subject was 0.04 mm on average. The occurrence of the periodontal pathogens A. actinomycetemcomitans, Capnocytophaga, and P. gingivalis in subgingival plaque did not differ between baseline and follow-up. The results of the present study indicate that the frequency of periodontitis, mainly located on the lower incisors, markedly increased during a 7-yr period in Down syndrome individuals, although the severity and progression was limited compared to what has previously been described. <52> UI - 99237905 AU - Scully C AU - El-Kabir M AU - Greenman J AU - Porter SR AU - Mutlu S AU - Barton I AU - Adair R IN - Department of Oral Medicine, Eastman Dental Institute for Oral Healthcare Sciences and International Centres for Excellence in Dentistry, University of London, UK. Cscully@eastman.ucl.ac.uk TI - The effects of mouth rinses and dentifrice-containing magnesium monoperoxyphthalate (mmpp) on oral microflora, plaque reduction, and mucosa. SO - Journal of Clinical Periodontology 1999 Apr;26(4):234-8 AB - The effects of a magnesium monoperoxyphthalate (MMPP) mouth-rinse, with or without sodium lauryl sulphate (SLS), and an MMPP dentifrice, on salivary counts of bacterial flora and yeasts, and on supragingival plaque scores were investigated in 131 healthy oral candida carriers over a 9 week double blind study. There were no changes in the salivary counts of bacteria studied (anaerobes, streptococci, fusobacteria, Actinomyces, Viellonella) in the test or placebo groups. A significant increase in salivary candida counts was seen in subjects using an MMPP rinse and dentifrice compared with placebo subjects and this phenomenon was not influenced by the presence of SLS. A significant reduction in plaque was seen in subjects using an MMPP rinse and dentifrice compared with placebo subjects. Frank candidosis was observed in only 2 subjects (1 in the placebo rinse group and 1 in the MMPP dentifrice group) but erythematous lesions, with subjective reports of soreness, dryness or burning sensation, were recorded and observed more frequently in the experimental groups than in the placebos, especially in those also using SLS. The substantial plaque reduction achieved with MMPP in the absence of tooth staining but with the increase in salivary Candida counts suggests that further studies of MMPP are warranted. <53> UI - 99240072 AU - Michalowicz BS AU - Wolff LF AU - Klump D AU - Hinrichs JE AU - Aeppli DM AU - Bouchard TJ Jr AU - Pihlstrom BL IN - Department of Preventive Sciences, School of Dentistry, University of Minnesota, Minneapolis, USA. TI - Periodontal bacteria in adult twins. SO - Journal of Periodontology 1999 Mar;70(3):263-73 AB - BACKGROUND: Both environmental and genetic factors are known to influence clinical measures of periodontal disease. The purpose of this study was to determine whether genetic factors similarly influence the presence of specific periodontal bacteria in subgingival plaque. METHODS: Reared-together and reared-apart monozygous (MZ) and dizygous (DZ) adult twins were examined clinically. Demographic and behavioral information was obtained from each subject by questionnaire. Subgingival plaque samples were obtained from the index teeth, and the presence of P. intermedia, P. gingivalis, A. actinomycetemcomitans, E. corrodens, and F. nucleatum was determined using an immunoassay. RESULTS: Microbiological and clinical data were available for 169 twin pairs. The subject-based prevalences of the bacteria in the twin groups ranged from 11% for Porphyromonas gingivalis to 40% for F. nucleatum. For all species examined, the concordance rates were not significantly different (P > 0.05) between MZ and DZ twin groups. These findings were apparent despite similar smoking histories, self-reported oral hygiene practices, and antibiotic use in the twin groups. Furthermore, MZ twins reared together were not more similar than MZ reared-apart twins with respect to any bacterial species examined. CONCLUSIONS: These findings suggest that in a population with access to routine dental care, any effects that host genes and the early family environment have on the presence of specific bacteria in subgingival plaque are not apparent in adulthood. Most twins with disease in this study had early periodontitis. Results from this study may not necessarily be extrapolated to more advanced disease states. <54> UI - 99259207 AU - Listgarten MA AU - Lai CH IN - Department of Periodontics, School of Dental Medicine, University of Pennsylvania, Philadelphia, USA. maxl@biochem.dental.upenn.edu TI - Comparative microbiological characteristics of failing implants and periodontally diseased teeth. SO - Journal of Periodontology 1999 Apr;70(4):431-7 AB - BACKGROUND: The purpose of this report was to compare the distribution of periodontal pathogens recovered from failing implants and teeth with adult and recurrent forms of periodontitis. METHODS: A total of 41 consecutive microbial samples from patients with failing implants (IMP) were received at the Microbiology Testing Laboratory (MTL) of the University of Pennsylvania over a 2-year period. Paired control samples were selected from samples received concurrently by MTL from 41 patients with a diagnosis of adult periodontitis (AP) and 41 with a diagnosis of recurrent or refractory periodontitis (RP). Patients' mean ages for the 3 categories were 59, 47, and 53 years, respectively. Samples were collected with paper points or scalers and shipped in prereduced medium by express mail to the laboratory where they were processed within 48 hours from the time of collection. Culture was used for detection of A. actinomycetemcomitans, C. rectus, P. intermedia/nigrescens, E. corrodens, P. micros, Capnocytophaga and Fusobacterium sp., enteric Gram-negative rods, Enterococcus and Staphylococcus sp., and yeast. P. gingivalis and B. forsythus were detected by indirect immunofluorescence. Morphotypes were enumerated by dark-field microscopy. RESULTS: The most frequently detected microorganisms from IMP were B. forsythus (59%), spirochetes (54%), Fusobacterium (41%), P. micros (39%), and P. gingivalis (27%). Recovery levels (mean +/- SD) were 1+/-1, 4+/-5, 4+/-5, 9+/-11, 1+/-2, respectively. The most frequently detected organisms for AP were B. forsythus (83%), Fusobacterium (80%), spirochetes (79%), P. gingivalis (59%), P. micros (51%), and E. corrodens (37%), at levels 2+/-2, 5+/-4, 9+/-6, 4+/-5, and 6+/-7, respectively. Corresponding data for RP were B. forsythus (85%), Fusobacterium (83%), P. gingivalis (60%), spirochetes (59%), C. rectus (56%), and P. micros (56%), at levels of 3+/-2, 8+/-8, 4+/-4, 2+/-2, 1+/-1, and 9+/-10, respectively. CONCLUSIONS: These results indicate that the detection frequency and levels of recovery of some periodontal pathogens in failing implants are significantly different from that of teeth with periodontitis; however, the detection frequency and levels of recovery are similar in teeth affected by adult and refractory (recurrent) forms of periodontitis. <55> UI - 99210273 AU - Paolantonio M AU - Festa F AU - di Placido G AU - D'Attilio M AU - Catamo G AU - Piccolomini R IN - Department of Periodontology, University "G. D'Annunzio" Chieti, Pescara, Italy. TI - Site-specific subgingival colonization by Actinobacillus actinomycetemcomitans in orthodontic patients. SO - American Journal of Orthodontics & Dentofacial Orthopedics 1999 Apr;115(4):423-8 AB - A high prevalence of Actinobacillus actinomycetemcomitans (Aa) in subgingival plaque in patients for orthodontia already has been observed. The present study had the following aims: 1) to ascertain a direct relationship between the orthodontic appliance placement and the subgingival colonization by Aa, and 2) to determine whether the Aa growth specifically occurred on teeth with braces attached or whether the presence of orthodontic appliances could also cause the isolation of Aa in teeth free from therapeutic appliances. Twenty-four young systemically and periodontally healthy subjects with malaligned and crowded teeth in the anterior sextants of both dental arches participated in this study. After 1 session of ultrasonic scaling with oral hygiene instructions during the first experimental session, the mesiobuccal sites of the first molars and the distobuccal sites of the lateral incisors in both dental arches in each participant were subjected to clinical and microbiologic examination for the recovery of Aa. Clinical examination consisted of recording the presence of plaque and the examination of gingival bleeding on probing and probing depth. Microbiologic sampling was obtained with the insertion of 3 sterile paper points at the deepest part of each gingival sulcus. Altogether, 192 periodontal sites were examined. After the examinations, the patients received fixed orthodontic appliances in only 1 dental arch (test sites) and the other one was left free from appliances (control sites). Clinical examination and microbiologic sampling were repeated in the same experimental test and control sites after 4, 8, and 12 weeks. At the 12-week session, the orthodontic appliance was removed from the test arch, and, 4 weeks later, a further clinical and microbiologic examination was performed. The results showed that, during the period with orthodontic appliances, the presence of plaque scores and the gingival bleeding on probing scores were increased significantly and that Aa, initially absent from all but 1 subject, was isolated in 19 and 20 subjects after 4 and 8 weeks, respectively. Furthermore, no gingival sites from the control teeth (free from Aa colonization at baseline) showed positive results for the sought-after bacterium throughout the entire length of the study. It was concluded that the placement of orthodontic appliances promotes the subgingival growth of Aa; this specific microbial change is specifically restricted to subgingival plaque from orthodontic appliance-bearing teeth. The presence of orthodontic bands and brackets therefore cannot affect the microbiologic condition of the whole mouth. <56> UI - 99160136 AU - Wong MY AU - Lu CL AU - Liu CM AU - Hou LT AU - Chang WK IN - School of Dentistry, College of Medicine, National Taiwan University, Taipei. veronica@ha.mc.ntu.edu.tw TI - Relationship of the subgingival microbiota to a chairside test for aspartate aminotransferase in gingival crevicular fluid. SO - Journal of Periodontology 1999 Jan;70(1):57-62 AB - BACKGROUND: The aim of the present study was to evaluate the association between the occurrence of certain specific periodontal pathogens and aspartate aminotransferase (AST) levels in gingival crevicular fluid (GCF). METHODS: Thirty systemically healthy subjects with moderate to advanced periodontitis were selected. Within each subject, the AST contents of GCF from sites with probing depth between 5 mm and 7 mm were measured using a chairside colorimetric test. AST-positive site refers to one that had an AST level > or = 800 microIU. Subgingival plaque samples from one AST-positive and one negative site were collected for microbiological examination. One site with probing depth < or = 3 mm and no gingival inflammation was selected as a healthy control. Clinical parameters of the chosen sites, including the plaque index and gingival index scores, probing depth, and clinical attachment level were measured. Culture and immunofluorescence (IF) were used for detecting common periodontal pathogens, including Actinobacillus actinomycetemcomitans, Peptostreptococcus micros, Campylobacter rectus, Eikenella corrodens, Fusobacterium nucleatum, Capnocytophaga species, Prevotella intermedia, Prevotella melaninogenica, and Porphyromonas gingivalis. Logistic regression was used to analyze the correlation between the AST test and certain specific pathogens. RESULTS: The GCF scores and total cultivable bacterial counts were higher in AST-positive sites than either AST-negative or healthy sites. The prevalence and proportions of specific periodontal pathogens such as C rectus, E. corrodens, F. nucleatum, Capnocytophaga species, P. intermedia, and P. gingivalis were significantly higher in positive than in negative sites. In analyzing the correlation of the proportion of 6 pathogens with the AST test by logistic regression, only P. gingivalis showed a significant positive correlation. The odds ratio of having a high proportion of P. gingivalis in the presence of a positive AST test was 1.21. CONCLUSIONS: The present study showed that at AST-positive sites, there is a higher prevalence and higher proportion of certain periodontal pathogens. Although only the correlation of P. gingivalis and AST values was statistically significant, the results imply that certain periodontal pathogens may be associated with elevation of AST levels in GCF. <57> UI - 99156429 AU - Berglundh T AU - Liljenberg B AU - Lindhe J IN - Department of Periodontology, Goteborg University, Sweden. berglundh@odontologi.gu.se TI - Some effects of periodontal therapy on local and systemic immunological parameters. SO - Journal of Clinical Periodontology 1999 Feb;26(2):91-8 AB - The aim of the present investigation was to study the effect of nonsurgical periodontal therapy on some local (gingival) and systemic host defense characteristics in subjects with advanced periodontal disease. 16 individuals with advanced periodontal disease were recruited. Following a clinical examination, the 3 deepest interproximal sites in the upper and lower premolar- or molar segments were selected for further analysis. Samples from the subgingival microbiota were obtained from the pocket of the selected sites and were prepared for a microbiological examination. The gingival tissue at one of the selected sites was also biopsied. Each excised soft tissue specimen was snap frozen and prepared for immunohistochemical analysis. A sample of peripheral blood was obtained from each individual and prepared for immunohistochemical analysis. Following the baseline examination, all 16 patients received periodontal therapy including oral hygiene instruction and scaling and root planing. Re-examinations regarding the clinical parameters were performed, the subgingival microbiota harvested from the sampling sites and one gingival biopsy was collected at 12 months and 24 months, respectively, among the selected sites. Samples of peripheral blood were obtained from the subjects at the 24-month re-examination. It was demonstrated that non-surgical periodontal therapy effectively reduced symptoms such as gingivitis and probing pocket depth in the subject sample and improved the overall probing attachment level. The treatment applied also markedly reduced (i) the total number of micro-organisms present in selected gingival pockets as well as (ii) the relative proportions of A. actinomycetemcomitans, P. gingivalis and P. intermedia of the subgingival microbiota. The improved clinical condition was, in addition, acc