Effect of initial periodontal therapy on the frequency of detecting Bacteroides forsythus, Porphyromonas gingivalis, and Actinobacillus actinomycetemcomitans.

BACKGROUND: Porphyromonas gingivalis, Bacteroides forsythus, and Actinobacillus actinomycetemcomitans have been described as periodontopathic bacteria, and their presence in subgingival pockets can lead to development of periodontal disease. Until now, clinical parameters have been used to evaluate the effect of conventional periodontal treatment without microbiological parameters. The present study examined the microbiological effects of initial periodontal therapy using DNA probes and the polymerase chain reaction (PCR). METHODS: Twenty-six patients with periodontitis, 10 males and 16 females, were given instructions regarding oral hygiene, then thoroughly treated by conventional scaling and root planing. Bacterial samples were collected on paper points from 4 sites per patient at baseline and after initial therapy (total: 104 sites). Clinical parameters including probing depth, attachment level, and bleeding on probing were also recorded for each site at baseline and after therapy. A DNA probe kit was used to monitor the frequency of B. forsythus, P. gingivalis, and A. actinomycetemcomitans, the last of which was identified by PCR. RESULTS: At baseline, B. forsythus was the bacterium most frequently detected. DNA probe analysis also showed that more than half of the sites were colonized by both B. forsythus and P. gingivalis. Initial therapy resulted in significant clinical improvement such as significant reduction in the frequency of B. forsythus and P. gingivalis detected using the DNA probe. A. actinomycetemcomitans was difficult to detect using the DNA probe, but PCR indicated that levels of A. actinomycetemcomitans did not significantly decrease. CONCLUSIONS: These results indicate that initial conventional therapy can eliminate B. forsythus and P. gingivalis, but not A. actinomycetemcomitans. When levels of these bacteria decreased to below-detectable levels, clinical improvement was significant. These results indicate that monitoring levels of these three periodontopathic bacteria may render periodontal therapy more effective and accurate.     

Repeated local metronidazole-therapy as adjunct to scaling and root planing in maintenance patients

The purpose of this investigation was to evaluate the effect of local antibiotic therapy with metronidazole adjunctively to scaling and root planing (SRP) versus mechanical treatment alone. 30 maintenance-patients were included in this single-blind study. The subjects had to comply with the following criteria: 2 non-adjacent sites with a probing depth > or =6 mm with bleeding on probing in separate quadrants, no periodontal therapy within the last 3 months, and no antibiotic therapy within the last 6 months. After randomization, the study sites were assigned to one of the following 2 treatments: SRP plus subgingival application of metronidazole 25% dental gel (Elyzol) 5x during 10 days (test site) or SRP alone (control site). Subgingival microbiological samples were taken prior to, and 21 days and 3 months after scaling. The samples were analyzed with a commercial chair-side ELISA (Evalusite) for Porphyromonas gingivalis, Prevotella intermedia and Actinobacillus actinomycetemcomitans. Probing pocket depth (PPD), attachment level (AL) and bleeding on probing (BOP) were recorded at baseline and 3 months later. PPD reduction and AL-gain were statistically significant (p<0.001) after both treatments. However, there were no statistically significant differences between them. The same observation was made for BOP. P. gingivalis was reduced significantly after both treatments without statistically significant differences. P. intermedia was reduced significantly only after SRP. A. actinomycetemcomitans was not reduced significantly after either treatment. In conclusion, the repeated local application of metronidazole as an adjunct to SRP and the mechanical treatment alone showed similar clinical and microbiological effects without statistically significant differences with the exception of P. intermedia.     

牙龈卟啉单胞菌与牙周基础治疗关系的实验研究

目的应用TaqMan实时荧光定量聚合酶链反应法检测慢性牙周炎患者牙周洁刮治术（SRP）治疗前后龈下菌斑中牙龈卟啉单胞菌（P. gingivalis）的变化,分析P. gingivalis与SRP疗效之间的关系,探讨应用实时荧光定量聚合酶链反应监测和评价SRP的可能性。方法选择20例中重度慢性牙周炎患者为研究对象,检查SRP治疗前后的临床指标,包括探诊深度（PD）、临床附着丧失（CAL）和探诊出血（BOP）;采集SRP治疗前后的龈下菌斑共142个样本,应用TaqMan实时荧光定量聚合酶链反应检测样本中的P. gingivalis。构建含有P. gingivalis扩增片段的重组质粒,建立定量标准。结果慢性牙周炎患者SRP治疗后PD、CAL和BOP均明显下降（P<0.001）;治疗前P. gingivalis检出率为80.28%,治疗后下降为54.23%;治疗前P. gingivalis数量与PD相关,Kendall相关系数为0.70（P<0.001）,治疗后牙周袋内细菌数量明显减少（P<0.001）。治疗前牙周袋内P. gingivalis的定植数量与PD、CAL和BOP的改善无相关性（P>0.05）,但治疗后治疗有效位点P. gingivalis数量减少程度明显大于治疗无效位点（P<0.05）,细菌减少量与PD改善弱相关（r=0.25,P=0.04）。结论SRP治疗可以明显改善临床症状,降低P. gingivalis检出率和绝对数量;治疗前P. gingivalis定植水平对临床指标的改善没有影响,治疗后P. gingivalis数量下降程度可以反映治疗效果。TaqMan实时荧光定量聚合酶链反应可以用于牙周炎治疗效果的监测和评价。     

Debridement and local application of tetracycline-loaded fibres in the management of persistent periodontitis: results after 12 months

BACKGROUNDS, AIMS: The aim of our study was to evaluate the clinical, radiological and microbiological response to the local delivery of tetracycline (TE) of sites with persistent periodontal lesions. MATERIALS AND METHODS: The study was conducted in a split-mouth design. Nineteen patients with at least four bilateral pockets 4-5 mm and bleeding on probing (BOP) were treated with scaling and root planing (SRP) plus TE fibres (test sites) or with SRP alone (control sites). Clinical and radiological measurements were taken at baseline, 6 months and 12 months post-operatively. Subgingival plaque samples were collected at baseline, at fibres removal, 6 and 12 months following treatment and analysed by polymerase chain reaction. RESULTS: Both treatments yielded a statistically significant (p<0.05) reduction of probing depth (2.05 and 1.21 mm), gain of clinical attachment level (1.71 and 0.53 mm) and reduction of BOP scores (23.68% and 57.89%) for TE and SRP groups, respectively, when comparing 12-month data with baseline. The differences between two groups were significant. The prevalence of Treponema denticola and Bacteroides forsythus decreased after therapy in both groups but only in the test sites Actinobacillus actinomycetemcomitans and Prevotella intermedia were not yield detected. The pathogens could be eliminated from five periodontal pockets by SRP alone, while 21 TE sites were not recolonized at 12 months. CONCLUSIONS: SRP plus TE fibres gave the greatest advantage in the treatment of periodontal persistent lesions at least 12 months following treatment.     

牙周基础治疗对慢性牙周炎患者临床指标及5种牙周可疑致病微生物的影响

目的:观察牙周基础治疗对临床指标及5种牙周可疑致病微生物的影响。方法:选取20例慢性牙周炎患者(40个位点),在治疗前和基础治疗后3个月时检测观测位点的临床指标牙周探诊深度(PPD),临床附着丧失(CAL)和探诊出血(BOP),同时采集龈下微生物样本。采用PCR和反杂交的方法对所采集微生物样本中的牙龈卟啉单胞菌、福赛斯坦纳菌,中间普氏菌、伴放线放线杆菌和齿垢密螺旋体进行半定量检测。结果:通过牙周基础治疗后临床指标PPD及BOP的改善具有统计学意义(P<0.001),而CAL的改善不具有统计学意义。治疗后牙龈卟啉单胞菌、福赛斯坦纳菌和齿垢密螺旋体的检出量显著减少(P<0.05或P<0.001)。治疗前PPD>6mm的位点只有福赛斯坦纳菌在治疗后比治疗前有显著减少(P<0.05),而牙龈卟啉单胞菌和齿垢密螺旋体的变化不具有统计学意义。结论:基础治疗是治疗慢性牙周炎的有效方法,可改善临床指标,减少龈下牙龈卟啉单胞菌、福赛斯坦纳菌和齿垢密螺旋体的数量。但在PPD>6mm的位点基础治疗对于这五微生物的影响作用是有限的。     

Relationship of changes in interleukin-8 levels and granulocyte elastase activity in gingival crevicular fluid to subgingival periodontopathogens following non-surgical periodontal therapy in subjects with chronic periodontitis

OBJECTIVES: To determine the effect of scaling and root planing (SRP) on the interrelations of subgingival periodontopathogens and both interleukin-8 (IL-8) and granulocyte elastase activity in gingival crevicular fluid (GCF), and to assess their relations to the short-term treatment response in management of chronic periodontitis. MATERIAL AND METHODS: GCF and subgingival plaque were collected from 16 subjects with untreated chronic periodontitis at baseline and 4 weeks after SRP. IL-8 levels were determined by ELISA. Granulocyte elastase activity was analyzed with a specific substrate, pGluProVal-pNA, and the maximal rate of elastase activity (MR-EA) was calculated. 5 DNA-probes were used to detect the presence of A. actinomycetemcomitans (A. a.), B. forsythus (B.f.), P. gingivalis (P.g.), P. intermedia (P.i.), and T. denticola (T.d.), with a sensitivity = 103 cells/paper point. RESULTS: IL-8 and MR-EA levels in GCF decreased significantly after SRP (p < 0.001) with a corresponding reduction of total count of the species. Of the sites with probing depth (PD) >/= 5.0 mm and co-infection by B.f., P.g., P.i. & T.d. at baseline, the sites without persistent co-infection of these species after SRP exhibited a significant reduction of IL-8 levels (p < 0.02), MR-EA levels (p < 0.02) and PD (p < 0.01). No such change was found in the sites where such a co-infection persisted. Moreover, reduction of IL-8 levels in those pocket sites was accompanied by a concomitant reduction of MR-EA (p < 0.02) and PD (p < 0.01), while no significant change in MR-EA levels and PD was noted in those pocket sites that exhibited an increase of IL-8 levels after SRP. At baseline, the former group of sites showed significantly higher IL-8 levels than the latter group of sites (p < 0.02). CONCLUSIONS: IL-8-related granulocyte elastase activity was related to the change in infection patterns of the target periodontopathogens following scaling and root planing. Varying initial IL-8 levels in GCF and a corresponding shifting change of granulocyte elastase activity in GCF may characterize the different short-term treatment responses.     

Porphyromonas gingivalis,Bacteroides forsythus and other putative periodontal pathogens in subjects with and without periodontal destruction

BACKGROUND AND AIMS: Bacteria play an essential role in the pathogenesis of destructive periodontal disease. It has been suggested that not all bacteria associated with periodontitis may be normal inhabitants of a periodontally healthy dentition. In particular, Porphyromonas gingivalis and Actinobacillus actinomycetemcomitans have been isolated infrequently from subjects without periodontitis. The aim of the present study was to compare prevalence and proportions of a number of periodontal bacteria in periodontitis patients and control subjects. MATERIAL AND METHODS: In all, 116 consecutive subjects diagnosed with moderate to severe periodontitis (mean age 42.4) and 94 subjects without radiographic evidence of alveolar bone loss (mean age 40.4) were recruited for the study. The gingival condition in the control group varied between gingival health and various degrees of gingivitis. In patients, the deepest pocket in each quadrant was selected for microbiological sampling. In control subjects all mesial and distal sites of all first molars were selected for sampling. All paper points from a patient were pooled and processed for anaerobic cultivation within 6 h after sampling. Clinical variables of sampled sites included bleeding index, probing pocket depth and clinical attachment level. RESULTS: A. actinomycetemcomitans, P. gingivalis, Prevotella intermedia, Bacteroides forsythus, Fusobacterium nucleatum and Peptostreptococcus micros were significantly more often prevalent in patients than in controls. The highest odds ratios were found for P. gingivalis and B. forsythus (12.3 and 10.4 resp.). Other odds ratios varied from 3.1 to 7.7 for A. actinomycetemcomitans and P. micros, respectively. Absolute numbers of target bacteria were all higher in patients, but only the mean percentage of B. forsythus was significantly higher in patients in comparison to controls (P < 0.001). CONCLUSIONS:A. actinomycetemcomitans, P. gingivalis, P. intermedia, B. forsythus, F. nucleatum and P. micros are all significant markers for destructive periodontal disease in adult subjects. Based on calculated odds ratios, B. forsythus and P. gingivalis are the strongest bacterial markers for this disease and are infrequently cultured from subjects without periodontal bone loss.     

The clinical and microbiological effects of systemic ornidazole in sites with and without subgingival debridement in early-onset periodontitis patients

BACKGROUND: The purpose of this study was to evaluate the clinical and microbiological effects of systemic ornidazole (ORN) in sites with or without subgingival debridement in early-onset periodontitis (EOP) patients. METHODS: Two pooled bacterial samples consisting of 4 sites each (scaled and non-scaled sites) were obtained from 30 individuals exhibiting EOP. All patients received oral hygiene instruction (OHI), supragingival scaling and ORN. Subgingival scaling and root planing (SRP) was carried out only in scaled sites. Bacterial samples were taken at baseline (BL) and 1 week and 2, 6, and 12 months after systemic ornidazole administration (500 mg/bid for 7 days). One more sample was taken at scaled sites, one week after SRP. RESULTS: One week following SRP (scaled sites) Gram-negative facultative and anaerobic rods were significantly reduced while Gram-positive facultative cocci were significantly increased. After ORN administration, P. gingivalis, P. denticola, P. intermedia, B. forsythus, C. rectus, and S. sputigena were no longer detectable in either scaled or non-scaled sites. A statistically significant long-term (2, 6, and 12 months) reduction of P. gingivalis, P. intermedia, P. loescheii, B. forsythus, and C. rectus and a pronounced increase of S. milleri, S. oralis, and S. sanguis counts in both scaled and non-scaled sites were detected in comparison to baseline. A sustained reduction of bleeding tendency and of probing depth was also observed in both scaled and non-scaled sites. CONCLUSIONS: ORN combined with SRP effects beneficial shifts in the bacterial population associated with substantial clinical improvement, thereby indicating that ORN is effective adjunct in the treatment of EOP deep periodontal pockets where anaerobic bacteria are predominant.     

Significance of detection of Porphyromonas gingivalis, Bacteroides forsythus and Treponema denticola in periodontal pockets

The relationship between the detection of Porphyromonas gingivalis, Bacteroides forsythus and Treponema denticola in subgingival plaque samples of periodontal pockets and periodontal status was evaluated using the polymerase chain reaction (PCR). A total of 165 sites in 60 periodontitis patients were examined, and the relationships between the detection of each of the three bacterial species and the pocket depth and bleeding on probing (BOP) were analyzed. The detection ratios of P. gingivalis, B. forsythus, and T. denticola in samples from adult periodontitis lesions were 75.5%, 69.8%, and 72.6%, respectively. It was found that all sites where all three microorganisms were detected were BOP positive and had greater pocket depths than those where only one or two species were found. The detection rate of B. forsythus and T. denticola decreased with age in the sites in which PD was less than 4 mm. The present study indicates that detection of a mixed infection by P. gingivalis, B. forsythus, and T. denticola strongly correlated with adult periodontitis.     

Initial effect of controlled release chlorhexidine on subgingival microorganisms

BACKGROUND: Little or no data exist on the ability of subgingival application of PerioChip (2.5 mg chlorhexidine gluconate in a biodegradable chip; Astra Pharmaceuticals, Westborough, MA, USA) to suppress periodontopathic microorganisms. The present study compared the subgingival microbiota of periodontitis sites receiving the chlorhexidine chip plus scaling and root planing (Sc/Rp) or Sc/Rp alone. METHODS: Seven males and six females, mean age 49 years, with moderate to advanced periodontitis participated in the study. In each patient, two bilateral pockets probing 6-7 mm were randomly assigned to treatment by chlorhexidine chip + Sc/Rp, or by Sc/Rp alone. Subgingival placement of chlorhexidine chips was carried out according to the manufacturer's instructions. Sc/Rp was performed with hand instruments for at least 10 min in each study tooth. Subgingival samples were collected by paper-points at baseline, at 2 weeks and at 4 weeks post-treatment. Anaerobic culture methods were used for microbial isolation and identification. The microbiologic examination was carried out blindly. Microbiological data were evaluated by a repeated measures analysis of variance. RESULTS: No statistical difference was found in total colony counts between subgingival sites treated with chlorhexidine chip + Sc/Rp and those treated with Sc/Rp alone. Also, the percentage of major periodontal pathogens (Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis and Bacteroides forsythus) and the percentage of total periodontal pathogens (A. actinomycetemcomitans, P. gingivalis, B. forsythus, Prevotella intermedia-group, Fusobacterium, Eubacterium, Campylobacter rectus, Peptostreptococcus micros, Eikenella corrodens, enteric rods) were not significantly different between the chlorhexidine chip + Sc/Rp group and the Sc/Rp group. At baseline, A. actinomycetemcomitans was recovered from 4 chlorhexidine chip + Sc/Rp sites and 2 Sc/Rp sites, P. gingivalis from 5 chlorhexidine chip + Sc/Rp sites and 4 Sc/Rp sites, and B. forsythus from 9 chlorhexidine chip + Sc/Rp and 7 Sc/Rp sites. At 4 weeks, A. actinomycetemcomitans was detected in 2 chlorhexidine chip + Sc/Rp sites but not in any site receiving Sc/Rp, P. gingivalis in 2 chlorhexidine chip + Sc/Rp sites but not in any Sc/Rp site, and B. forsythus in 1 chlorhexidine chip + Sc/Rp and in 2 Sc/Rp sites. CONCLUSION: The present data obtained from bilateral periodontitis lesions of 13 adults suggest that chlorhexidine chip treatment of adult periodontitis lesions provides little or no additional antimicrobial benefits compared to thorough Sc/Rp alone.     

Changes in subgingival microflora and humoral immune response following periodontal therapy

OBJECTIVES: To investigate the effect of scaling and root planing (SRP) on the microflora and humoral immune response in adult periodontitis. MATERIALS & METHODS: Clinical measurements, subgingival plaque samples, gingival crevicular fluid and sera were taken from 4 sites in 28 adult periodontitis patients before and after SRP. Polymerase chain reaction was used to determine the presence of A. actinomycetemcomitans, P. gingivalis, B. forsythus, P. intermedia, and T. denticola. ELISA was used to investigate the systemic and local antibody titres to these organisms, and thiocyanate dissociation for the determination of serum antibody avidity. RESULTS: SRP produced a good clinical improvement. On a subject basis there was little significant change in the microflora. However, on a site basis, there were significant reductions in P. intermedia, B. forsythus and T. denticola. There was little change in systemic and local antibody titres following SRP, although there was a significant reduction in antibody avidity to P. gingivalis and P. intermedia CONCLUSION: Post-therapy clinical improvement was associated with a reduction in bacterial prevalence, but statistical significance was only reached at a site level and this microbial reduction was not significant for all organisms. No significant post-therapy effects on the humoral immune response were noted other than a reduced antibody avidity to P. gingivalis and P. intermedia. The lack of a clear pattern in the humoral immune response may reflect a failure of the host response to produce adequate levels of biologically functional antibodies, and complex interactions between the subgingival flora and the host response.     

Prevalence of Bacteroides forsythus, Porphyromonas gingivalis and Actinobacillus actinomycetemcomitans in subgingival microflora of Japanese patients with adult and rapidly progressive periodontitis

BACKGROUND, AIMS: This study investigated the prevalence of Bacteroides forsythus, Porphyromonas gingivalis and Actinobacillus actinomycetemcomitans among various periodontitis patients and healthy individuals in Japan, and correlated it with clinical parameters. METHOD: Subgingival plaque samples were collected from 21 patients with adult periodontitis (AP), 8 with rapidly progressive periodontitis (RPP) and 15 healthy individuals. RESULTS: The frequency detected in culture was as follows: B. forsythus was found in 47.6% of AP sites and in 37.5% of RPP sites. P. gingivalis was identified in 64.3% of AP and 59.4% of RPP sites. A. actinomycetemcomitans was detected in 4.8% of AP and 3.1% of RPP sites. The 3 species were detected in only 2 of the healthy individuals. The proportion of B. forsythus in the total microflora in culture was 0.07% in the healthy group, 4.1% in AP and 2.4% in RPP. The proportions of P. gingivalis were 0% in the healthy group, 18.8% in AP and 16.2% in RPP. The proportion of A. actinomycetemcomitans was very low in all 3 groups. A DNA probe detected B. forsythus in 78.6% of AP and 65.6% of RPP sites, as well as P.gingivalis in 58.3% of AP and 59.4% of RPP sites. A. actinomycetemcomitans was detected in only 1.2% of AP sites. The 3 species were undetectable in the healthy group. CONCLUSIONS: The prevalence and the proportion of B. forsythus and P. gingivalis were significantly correlated with clinical parameters, suggesting that B. forsythus and P. gingivalis are closely related to AP and RPP in the Japanese population.     

Clinical and microbiologic changes after removal of orthodontic appliances.

The goal of this study was to evaluate the clinical and microbiological factors associated with orthodontic appliances during an episode of gingival inflammation and the impact of appliance removal on periodontal health. This prospective study included 10 patients, aged 12 to 20 years, with clinical signs of gingival inflammation at the final phase of orthodontic treatment (appliance removal). Plaque index, gingival index, and probing depth were evaluated, and microbiological samples were collected from teeth 16, 11, and 26 at 2 times: during the gingival inflammation (baseline) and 30 days after the removal of the appliance and professional prophylaxis. Polymerase chain reaction analysis was used to detect Porphyromonas gingivalis, Bacteroides forsythus, Actinobacillus actinomycetemcomitans, Prevotella intermedia, and Prevotella nigrescens. A statistically significant improvement of the plaque and gingival indexes was seen, as well as a reduction in probing depth (P <.05). Periodontal pathogens were associated with gingival inflammation during orthodontic treatment. The improvement in periodontal health at 30 days was concomitant with a reduction of sites positive for A. actinomycetemcomitans and B. forsythus (P <.05). Periodontal pathogens associated with gingival inflammation during orthodontic treatment can be significantly reduced by orthodontic appliance removal and professional prophylaxis.     

Involvement of Porphyromonas gingivalis fimA genotype in treatment outcome following non-surgical periodontal therapy

BACKGROUND: Porphyromonas gingivalis is considered a critical pathogen in periodontal diseases. It is classified into six genotypes based on diversity of the fimA gene encoding fimbrillin. The present study evaluated the involvement of the fimA genotype in treatment outcome following non-surgical periodontal therapy. METHODS: Chronic periodontitis patients were enrolled in this study; all received clinical and microbiological examinations at baseline. The detection of subgingival species and identification of P. gingivalis fimA genotypes were performed using polymerase chain reaction based methods. In total, 160 P. gingivalis positive sites with bleeding on probing (BOP) and a probing depth of > or =4 mm were accepted. They were followed up after scaling and root planing. RESULTS: Longitudinal investigation indicated that fimA type I positive sites at baseline were followed by a significantly higher frequency of persistent BOP after treatment than type I negative sites (51.6% versus 27.9%), while types Ib and II were not. Type I positive sites also showed more persistence of Tannerella forsythensis and P. gingivalis after treatment than type I negative sites. In post-treatment investigation, type I positive sites showed higher frequencies of BOP and T. forsythensis detection than type I negative sites (77.8% versus 43.5% and 100% versus 76.1%, respectively). CONCLUSIONS: BOP in initially type I positive sites showed little improvement with treatment, and the combined persistence of fimA type I and T. forsythensis seemed to be involved in this poor treatment outcome. The present study demonstrated the potential of P. gingivalis fimA type I as a predictor of persistent BOP after treatment.     

Effects of non-surgical mechanical therapy on the subgingival microbiota of Brazilians with untreated chronic periodontitis: 9-month results

BACKGROUND: Mechanical periodontal therapy is the most common treatment of periodontal infections. It is directed primarily towards removing biofilm and calculus from the root surfaces, leading to ecological changes in the subgingival environment. Thus, the purpose of this study was to evaluate the effects of scaling and root planing (SRP) on the subgingival microbiota of Brazilian subjects with untreated chronic periodontitis over a 9-month period. METHODS: Twenty-five untreated chronic periodontitis patients (mean age 43 +/- 5 years; 20% smokers; 45% males) were selected from a Brazilian population. At baseline, probing depth (PD), clinical attachment level (CAL), visible supragingival biofilm (SB), bleeding on probing (BOP), and suppuration (SUP) were measured at six sites/tooth. Subgingival plaque samples were obtained from 10 sites with the deepest PD (> or =5 mm) of each subject and tested for the presence of 25 oral species by DNA probes and the checkerboard technique. Patients received full mouth SRP and oral hygiene instructions. Clinical and microbiological assessments were repeated at 3, 6, and 9 months after therapy. During this period, all patients received maintenance therapy, including supragingival prophylaxis and reinforcement in home care procedures. The clinical and microbiological parameters examined were computed for each subject and at each visit. Differences over time were sought using the Friedman test. RESULTS: Significant reductions in mean CAL and PD (P <0.01), percent of sites with SB (P <0.01), BOP and SUP (P <0.05) were observed during the course of the study. In general, microbial changes were more pronounced for the mean counts than for the frequency of the microorganisms, particularly at 3 months post-therapy. Significant reductions in prevalence and levels were observed for certain periodontal pathogens including P. gingivalis (P <0.05; P <0.01), T. forsythensis (P <0.01), C. rectus (P <0.01), and A. actinomycetemcomitans (P <0.01; P <0.05). Nevertheless, the frequency of A. actinomycetemcomitans increased to baseline values at 9 months after therapy. Treponema ssp. and Prevotella spp. showed a modest decrease in prevalence, whereas marked reductions in their levels were observed. In contrast, the frequency and counts of the suspected pathogens P. micros and F. nucleatum increased after treatment. Species considered beneficial including Actinomyces spp., some oral streptococci, and V. parvula increased in prevalence, although these two last species tended to return to baseline levels at 9 months. CONCLUSION: In Brazilians with untreated chronic periodontitis, SRP led to clinical improvement associated with a decrease of certain periodontal pathogens, and an increase of beneficial species for up to 9 months after therapy.     

Microbiological response of localized sites with recurrent periodontitis in maintenance patients treated with tetracycline fibers.

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.     

Detection of periodontopathic bacteria and an oxidative stress marker in saliva from periodontitis patients

We assessed the salivary levels of periodontopathic bacteria and 8-hydroxydeoxyguanosine (8-OHdG) in patients with periodontitis. The salivary levels of Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, and Tannerella forsythia (formerly Bacteroides forsythus) were assessed using real-time polymerase chain reaction. The 8-OHdG levels were determined using an enzyme-linked immunosorbent assay. The salivary levels of 8-OHdG, P. gingivalis, and T. forsythia in the periodontitis patients were significantly higher than those in healthy subjects. By contrast, the A. actinomycetemcomitans level in healthy subjects was higher than that in periodontitis patients. 8-OHdG was significantly correlated with P. gingivalis. Statistically significant decreases in the levels of P. gingivalis, probing depth, bleeding on probing, and 8-OHdG were observed after initial periodontal treatment. These results suggest that the 8-OHdG levels in saliva reflect the load of periodontal pathogens. 8-OHdG could be a useful biomarker for assessing periodontal status accurately, and for evaluating the efficacy of periodontal treatment.     

Sulfate-reducing bacteria in relation with other potential periodontal pathogens

BACKGROUND, AIMS: Oral sulfate-reducing bacteria are involved in several clinical categories of periodontitis. The aim of this cross-sectional study was to compare the presence of sulfate-reducing bacteria (SRB) with other putative pathogens including spirochetes, Actinobacillus actinomycetemcomitans, Bacteroides forsythus, Porphyromonas gingivalis, and Treponema denticola in periodontal lesions. METHOD: Periodontal SRB were detected by enrichment culture and compared with a microscopic spirochete count (n=168). Species-specific oligonucleotide probes directed against the 16S rRNA were employed to determine the presence of A. actinomycetemcomitans, P. gingivalis, B. forsythus, and T. denticola (n=55). RESULTS: A significant positive correlation was observed between the presence of SRB and the proportions of spirochetes in subgingival plaque, although the 2 bacterial groups also occurred separately. SRB tended to be negatively correlated with the presence of A. actinomycetemcomitans. In contrast, all pockets with SRB harbored either T. denticola, or both T. denticola and B. forsythus (12/14) before therapy. Interestingly, the combination of SRB with P. gingivalis occurred in 32% of the periodontal pockets before treatment. After initial periodontal therapy, the prevalence of this combination was reduced to 2% of the sites, and to 25% of the sites in recall patients. CONCLUSION: The presence of SRB was positively correlated with T. denticola, B. forsythus, and P. gingivalis in periodontal lesions. These suspected pathogens form a complex strongly associated with destructive periodontitis.     

Clinical and microbiological effects of different antimicrobials on generalized aggressive periodontitis

AIM: To evaluate and compare the effects of adjunctive metronidazole plus amoxicillin, doxycycline and metronidazole on clinical and microbiological parameters in patients with generalized aggressive periodontitis. MATERIAL AND METHODS: Forty-three patients participated in this randomized clinical trial divided into four groups. Six weeks after scaling and root planning (SRP), groups 1-3 received adjunctive metronidazole, plus amoxicillin, doxycycline and metronidazole respectively, and group 4 acted as controls. Clinical recordings concerning probing depth, probing attachment level and bleeding on probing were performed at baseline, 6 weeks after SRP and 6 months from baseline. Subgingival samples were analysed using the 'checkerboard' DNA-DNA hybridization for Porphyromonas gingivalis, Actinobacillus actinomycetemcomitans, Tannerella forsythia and Treponema denticola. Results: All treatments resulted in improvement of clinical parameters (ANOVA p > 0.05). Systemic administration of metronidazole plus amoxicillin or metronidazole resulted in statistically significant greater reduction of the proportion of sites > 6 mm than SRP (z-test, p < 0.05). These antimicrobials yielded a significant effect on levels of important periodontal pathogens for 6 months. CONCLUSION: Adjunctive metronidazole plus amoxicillin or metronidazole alone (when A.actinomycetemcomitans is not involved) is effective in deep pockets of aggressive periodontitis patients.     

Topical use of a metronidazole gel in the treatment of sites with symptoms of recurring chronic inflammation

BACKGROUND: Bacterial plaque accumulation at the dentogingival junction and in periodontal pockets is the major etiologic factor in all manifestations of periodontal disease. The aim of this study was to evaluate whether a locally delivered 25% metronidazole gel after scaling and root planing (SRP) would enhance the treatment outcome over SRP alone in periodontal pockets with symptoms of recurring chronic inflammation. METHODS: Twenty-one maintenance-care patients, 10 men and 11 women, having at least one pair of contralateral anatomically matching proximal tooth surfaces showing probing depth > or = 5 mm and bleeding on probing (BOP), were included in the study. The sites were randomized to be treated with SRP plus 25% metronidazole gel (test sites) or with SRP alone (control sites) in a split-mouth design. Clinical evaluations were performed immediately pretreatment (baseline) and at 3 and 6 months post-treatment. RESULTS: Both treatments yielded a statistically significant (P = 0.001) reduction in probing depth (1.9 and 1.8 mm), gain of attachment level (1.6 and 1.0 mm), and reduction of BOP (38.1% and 33.3%) for test and control sites, respectively, at 6 months. There was no statistically significant difference between the treatments for any of the clinical parameters. CONCLUSION: This study indicates that a locally applied 25% metronidazole gel does not improve the treatment outcome over SRP alone in sites with recurring chronic inflammation in maintenance-care patients.