This chapter deals with the types of disease, the factors involved in their etiology, and considers measures to prevent and control periodontal disease. Gingivitis is the earliest clinically detectable stage of periodontal disease and is characterized by inflammation of the marginal gingivae. Juvenile periodontitis, formerly referred to as periodontosis, is a destructive form of periodontitis, characterized by early onset and rapid bone destruction. The first signs of the slowly progressive adult type of periodontitis may be found as early as late puberty. Cocci and short rods comprise the plaque associated with healthy periodontal tissues, whereas distinctly different microbial complexes are associated with disease sites. The establishment and progress of periodontal disease depend on the intricate interplay between exogenous factors originating from pathogenic bacteria and the response of the host tissues. A variety of systemic diseases have been found to affect the development of periodontal disease.

Aim: To understand degeneration of healthy sites and identify factors associated with disease progression in patients with chronic periodontitis.Material and Methods: Data on healthy sites from 163 American and Swedish subjects were analysed using two-three-state (health, gingivitis, chronic periodontitis) Markov models based on bleeding on probing (BOP), and either clinical attachment level (CAL) + BOP or pocket depth (PD) + BOP.Results: In 2 years, 10% (CAL + BOP) and 3% (PD + BOP) of healthy sites developed chronic periodontitis. On average, healthy sites remained healthy for 32 months before transiting in both models. Most transitions (87-97%) from health were to the gingivitis state. The expected duration of the gingivitis lesion was 4-5 months and sites recovered with a high probability (96-98%). Disease severity as measured by number of sites with CAL/PD > 4 mm at baseline and smoking, were associated with fast progression from health to chronic periodontitis within 6 months as were gingival redness in the PD + BOP model only. With age, the rate of disease progression to gingivitis decreased.Conclusion: Transition probabilities for gingivitis and chronic periodontitis were higher with CAL + BOP than with PD + BOP. Smoking and disease severity were significant predictors for fast progression.

AimTo follow changes (over 2 years) in subgingival bacterial counts of five microbial complexes including health-related Actinomyces spp. in deeper pockets (≥5 mm) after periodontal treatments.MethodsEight different treatments were studied: (1) scaling+root planing (SRP); (2) periodontal surgery (SURG)+systemic amoxicillin (AMOX)+systemic metronidazole (MET); (3) SURG+locally delivered tetracycline (TET); (4) SURG; (5) AMOX+MET+TET; (6) AMOX+MET; (7) TET; and (8) SURG+AMOX+MET+TET. Antibiotics were given immediately following SRP. Subgingival plaque was collected mesiobuccally from each tooth, except third molars, from 176 subjects, completing the study, at baseline, 3, 6, 12, 18, and 24 months post-treatment and analysed for 40 different bacteria using checkerboard hybridization. A negative binomial (NB) generalized estimating equation (NB GEE) model was used to analyze count data and a logistic GEE was used for proportions.ResultsWe observed short-term beneficial changes in the composition of the red complex of up to 3 months by treating subjects with AMOX+MET+TET. Similar short-term improvements with the same treatment were observed for Tannerella forsythia and Treponema denticola of the red complex. SURG had also short-term beneficial effect on Porphyromonas gingivalis. No periodontal treatments applied to severely affected sites promoted the growth of Actinomyces. Smoking elevated counts of both the red and orange complex while bleeding on probing (BOP) and gingival redness were also predictors of more red complex counts. Comparatively similar findings were obtained by analyzing counts and by analyzing proportions.ConclusionsAlthough short-term reductions in the counts of the red complex were observed in sites that were treated with AMOX+MET+TET, long-term significant effects were not observed with any of the eight treatments. Poor oral hygiene in patients with severe chronic periodontitis diminished the beneficial effects of treatment.

AimTo evaluate the changes occurring in the subgingival microbial profile of subjects with generalized chronic periodontitis (ChP) treated by scaling and root planing (SRP) alone or with metronidazole (MTZ) or MTZ+amoxicillin (AMX). A secondary aim was to examine a possible added effect of chlorhexidine (CHX) to these therapies.MethodsOne hundred and eighteen subjects were randomly assigned to receive SRP-only or with MTZ [400mg/thrice a day (TID)] or MTZ+AMX (500mg/TID) for 14days. Half of the subjects in each group rinsed with 0.12% CHX twice a day (BID) for 2months. Nine subgingival plaque samples/subject were analysed by checkerboard DNA-DNA hybridization for 40 bacterial species at baseline, 3, 6 and 12months post-therapy.ResultsAt 12months, the antibiotic-treated groups harboured lower mean counts and proportions of key periodontal pathogens than the SRP group (p<0.05). These benefits were observed at initially deep and shallow sites. Initial reductions in periodontal pathogens obtained with SRP partially rebound after 12months. CHX rinsing enhanced the microbiological effects of the MTZ+AMX treatment in shallow sites.ConclusionThe adjunctive use of MTZ and MTZ+AMX results in a greater reduction in the levels of periodontal pathogens in generalized ChP subjects compared to SRP alone.

AIM To examine the 2-year post-therapy kinetics of change in the composition of subgingival biofilms. MATERIAL AND METHODS In this study, 178 chronic periodontitis subjects were recruited and clinically monitored at baseline, 3, 6, 12, 18 and 24 months after therapy. All subjects received scaling and root planing and 156 one or more of periodontal surgery, systemically administered amoxicillin + metronidazole or local tetracycline at pockets ≥5 mm. Subgingival biofilm samples taken from each subject at each time point were analysed for their content of 40 bacterial species using checkerboard DNA-DNA hybridization. The significance of changes in median species counts over time was sought using the Wilcoxon or Friedman tests and adjusted for multiple comparisons. RESULTS Mean counts were significantly reduced from baseline to 2 years for 30 of the 40 taxa. Marked reductions were observed for periodontal pathogens including Tannerella forsythia, Treponema denticola and Eubacterium nodatum. The kinetics of change differed from species to species. When data were subset according to baseline PD, patterns of change in the microbial profiles were generally similar. CONCLUSION Periodontal therapy leads to a rapid reduction in periodontal pathogens, followed by a slower reduction in other taxa that can be sustained for at least 2 years.

Aim To evaluate the effects of the adjunctive use of metronidazole (MTZ) or MTZ + amoxicillin (AMX) in the treatment of generalized chronic periodontitis (ChP). A secondary aim was to examine a possible added effect of chlorhexidine to these therapies. Methods One hundred and eighteen subjects received scaling and root planing (SRP) only or with MTZ [400 mg/thrice a day (TID)] or MTZ+AMX (500 mg/TID) for 14 days. Half of the subjects in each group rinsed with 0.12% chlorhexidine twice a day (BID) for 2 months. Subjects were clinically monitored at baseline, 3, 6 and 12-months post-therapy. Results The two antibiotic groups showed lower mean number of sites with probing depth (PD) =5 mm and fewer subjects exhibiting =9 of these sites at 1-year post-treatment. Logistic regression analysis showed that antibiotics were the only significant predictors of subjects presenting =4 sites with PD =5 mm at 1 year (MTZ+AMX: OR, 13.33; 95%CI, 3.75-47.39/p = 0.0000; MTZ: OR, 7.26; 95%CI, 2.26-23.30/p = 0.0004). The frequency of adverse events did not differ between the two antibiotic treatments (p > 0.05). The chlorhexidine subgroups showed a trend (p > 0.05) to present fewer residual sites =5 mm compared with the placebo subgroups at 1 year. Conclusion Treatment of generalized ChP is significantly improved by the adjunctive use of MTZ+AMX and MTZ.

Aim Find the periodontal treatment that best maintained clinical results over time evaluated by changes in pocket depth (PD) and clinical attachment level (CAL). Methods 229 patients with chronic periodontitis from USA (n=134) and Sweden (n=95) were randomly assigned to eight groups receiving 1 scaling+root planing (SRP) alone or combined with 2 surgery (SURG)+systemic amoxicillin (AMOX)+systemic metronidazole (MET); 3 SURG+local tetracycline (TET); 4 SURG; 5 AMOX+MET+TET; 6 AMOX+MET; 7 TET; and 8 SURG+AMOX+MET+TET. Antibiotics were given immediately after SRP. Plaque, gingival redness, bleeding on probing, suppuration, PD, and CAL were recorded at baseline and after 3, 6, 12, 18, and 24 months. Treatment effects were evaluated by linear multilevel regression and logistic multilevel regression models. We considered only data from sites with a baseline PD of at least 5 mm of 187 patients completing the study. Results Surgically treated patients experienced most CAL loss. Adjunctive therapy including SURG was most effective in reducing PD. Combining SURG with AMOX, MET, and TET gave significant clinical benefits. Past and current smoking habits were significant predictors of deeper PD. Only current smoking was a significant predictor of CAL loss. Bleeding, accumulation of plaque, gingival redness, and suppuration were significant predictors of further CAL loss and deeper PD. Conclusions Both surgical and non-surgical therapies can be used to arrest chronic periodontitis. SURG+AMOX+MET+TET gave best maintenance of clinical results.

Background: This study compares the changes to the subgingival microbiota of individuals with “refractory” periodontitis (RP) or treatable periodontitis (good responders [GR]) before and after periodontal therapy by using the Human Oral Microbe Identification Microarray (HOMIM) analysis.Methods: Individuals with chronic periodontitis were classified as RP (n = 17) based on mean attachment loss (AL) and/or >3 sites with AL ≥2.5 mm after scaling and root planing, surgery, and systemically administered amoxicillin and metronidazole or as GR (n = 30) based on mean attachment gain and no sites with AL ≥2.5 mm after treatment. Subgingival plaque samples were taken at baseline and 15 months after treatment and analyzed for the presence of 300 species by HOMIM analysis. Significant differences in taxa before and post‐therapy were sought using the Wilcoxon test.Results: The majority of species evaluated decreased in prevalence in both groups after treatment; however, only a small subset of organisms was significantly affected. Species that increased or persisted in high frequency in RP but were significantly reduced in GR included Bacteroidetes sp., Porphyromonas endodontalis, Porphyromonas gingivalis, Prevotella spp., Tannerella forsythia, Dialister spp., Selenomonas spp., Catonella morbi, Eubacterium spp., Filifactor alocis, Parvimonas micra, Peptostreptococcus sp. OT113, Fusobacterium sp. OT203, Pseudoramibacter alactolyticus, Streptococcus intermedius or Streptococcus constellatus, and Shuttlesworthia satelles. In contrast, Capnocytophaga sputigena, Cardiobacterium hominis, Gemella haemolysans, Haemophilus parainfluenzae, Kingella oralis, Lautropia mirabilis, Neisseria elongata, Rothia dentocariosa, Streptococcus australis, and Veillonella spp. were more associated with therapeutic success.Conclusion: Persistence of putative and novel periodontal pathogens, as well as low prevalence of beneficial species was associated with chronic refractory periodontitis.

Objective To compare the treatment outcome of scaling and root planing (SRP) in combination with systemic antibiotics, local antibiotic therapy and/or periodontal surgery. Material and Methods One hundred and eighty-seven patients were assigned to eight groups treated by SRP plus none, one, two or three adjunctive treatments and monitored for 24 similar to months in a randomized controlled clinical trial using a 2 similar to 2 similar to 2 factorial design. Systemic amoxicillin similar to metronidazole (SMA), local tetracycline delivery (LTC) and periodontal surgery (SURG) were evaluated as adjuncts. Changes in clinical attachment level (CAL) and probing pocket depth (PPD) were statistically evaluated by ancova of main effects. Results Effects of adjunctive therapy to SRP were minimal at 3 similar to months. Between 3 and 6 similar to months PPD reduction occurred particularly in patients receiving periodontal surgery. After 6 similar to months, both CAL gain and PPD reduction reached a plateau that was maintained at 24 similar to months in all groups. The 24-month CAL gain was improved by SMA (0.50 similar to mm) while PPD was reduced by SMA (0.51 similar to mm) and SURG (0.36 similar to mm). Smoking reduced CAL gain and PPD reduction. Conclusion Patients receiving adjunctive therapies generally exhibited improved CAL gain and/or PPD reduction when compared with the outcome of SRP alone. Only additive, not synergistic effects of the various adjunctive therapies were observed.

AIM To examine changes in levels of gingival crevicular fluid (GCF) cytokines, after periodontal therapy of generalized aggressive periodontitis (GAgP). MATERIALS AND METHODS Twenty-five periodontally healthy and 24 GAgP subjects had periodontal clinical parameters measured and gingival crevicular fluid (GCF) samples collected from up to 14 sites/subject. GCF samples were analysed using multiplex bead immunoassay for: GM-CSF, IFN-γ, IL-10, IL-1β, IL-2, IL-6 and TNF-α. Aggressive periodontitis subjects were randomly assigned to either scaling and root planing (SRP) alone or SRP plus systemic amoxicillin (500 mg) and metronidazole (400 mg) 3 times a day for 14 days. Clinical parameters and GCF cytokines were re-measured 6 months after treatment. Differences over time were analysed using the Wilcoxon test and between groups using the Mann-Whitney test. RESULTS Significant reductions in GCF GM-CSF, IL-1β and the ratio IL-1β/IL-10 and increases in GCF IL-6 were detected after therapy. The mean change in GCF cytokines did not differ significantly between groups. CONCLUSIONS Periodontal therapy improved GCF cytokine profiles by lowering IL-1β and increasing IL-10 levels. The reduction in GCF GM-CSF after therapy implicates this cytokine in the pathogenesis of GAgP. There was no difference between therapies in changes of GCF cytokines.

Background: The aim of this study is to explore relationships among serum adipokines, vitamin D, and clinical and microbial parameters of chronic periodontitis before and after treatment.Methods: Weight, height, and smoking status were recorded for 56 patients with chronic periodontitis. Plaque, gingivitis, bleeding on probing, suppuration, probing depth, and clinical attachment level were measured at all teeth present. Subgingival biofilm samples from each tooth were analyzed for levels of 40 bacterial species using checkerboard DNA DNA hybridization. Serum levels of interleukin-6 (IL-6), tumor necrosis factor-a, adiponectin, leptin, resistin, and vitamin D were measured at baseline. Sample collection was then performed in a subset of the population 6 months after therapy (n = 17). Serum samples were analyzed using enzyme-linked immunosorbent assay and immunoassays. Differences in clinical, microbial, and serum factors among groups were sought using the Mann-Whitney U test. Correlations among factors were evaluated using regression analysis. Effects of therapy were sought using the Wilcoxon signed rank test.Results: There were positive correlations between adiponectin/vitamin D and between IL-6/leptin, negative correlations between IL-6/vitamin D and leptin/vitamin D, but no associations between serum analytes and clinical or microbial parameters. Sex and body mass index were associated with levels of adipokines. Periodontal therapy improved clinical and microbiologic parameters but did not influence the levels of serum analytes.Conclusion: Adipokines and IL-6 levels were affected by sex and body mass index. Serum analytes were not influenced by periodontal therapy. J Periodontol 2012;83:1183-1191.

AIM To monitor microbial shifts during dental biofilm re-development. MATERIALS AND METHODS Supra- and subgingival plaque samples were taken separately from 28 teeth in 38 healthy and 17 periodontitis subjects at baseline and immediately after tooth cleaning. Samples were taken again from seven teeth in randomly selected quadrants during 1, 2, 4 and 7 days of no oral hygiene. Samples were analysed using checkerboard DNA-DNA hybridization. Species counts were averaged within subjects at each time point. Significant differences in the counts between healthy and periodontitis subjects were determined using the Mann-Whitney test. RESULTS The total supra- and subgingival counts were significantly higher in periodontitis on entry and reached or exceeded the baseline values after day 2. Supragingival counts of Veillonella parvula, Fusobacterium nucleatum ss vincentii and Neisseria mucosa increased from 2 to 7 days. Subgingival counts were greater for Actinomyces, green and orange complex species. Significant differences between groups in supragingival counts occurred for 17 of 41 species at entry, 0 at day 7; for subgingival plaque, these values were 39/41 taxa at entry, 17/41 at day 7. CONCLUSIONS Supragingival plaque re-development was similar in periodontitis and health, but subgingival species recolonization was more marked in periodontitis.

BACKGROUND:The objectives of this study were to measure levels of gingival crevicular fluid (GCF) biomarkers and subgingival bacterial species in periodontally healthy subjects and subjects with periodontitis to explore the relationships among these biomarkers, the subgingival microbiota, and the clinical parameters of periodontal disease. METHODS:Clinical periodontal parameters were measured at six sites per tooth in 20 subjects with periodontitis and 20 periodontally healthy subjects. GCF and subgingival plaque samples were obtained from the mesio-buccal aspect of every tooth. GCF levels of interleukin (IL)-1beta and IL-8 and matrix metalloproteinase 8 were measured using checkerboard immunoblotting, and the levels of 40 bacterial taxa were quantified using checkerboard DNA-DNA hybridization. A subset of "clinically healthy" sites from each group was analyzed separately. The significance of the differences between groups was determined using the unpaired t test or the Mann-Whitney test. Correlations among immunologic, microbiologic, and clinical data were determined using the Spearman rank correlation coefficient. RESULTS:There were positive correlations among mean clinical parameters, mean levels of the three biomarkers, and the proportions of orange and red complex species (P <0.05). Clinically healthy sites from subjects with periodontitis had higher levels of IL-1beta and IL-8 and higher proportions of orange and red complex species (P <0.05) than clinically healthy sites from periodontally healthy subjects. Red complex species were positively associated with the expression of all biomarkers (P <0.05), whereas purple and yellow complex species had negative correlations with IL-1beta and IL-8 (P <0.05). CONCLUSIONS:Clinically healthy sites from subjects with periodontitis have higher levels of GCF biomarkers and periodontal pathogens than clinically healthy sites from periodontally healthy subjects. Different microbial complexes demonstrated distinct associations with specific GCF biomarkers.

AIM:To examine relationships between subgingival biofilm composition and levels of gingival crevicular fluid (GCF) cytokines in periodontal health and generalized aggressive periodontitis (GAP). MATERIALS AND METHODS:Periodontal parameters were measured in 25 periodontally healthy and 31 GAP subjects. Subgingival plaque and GCF samples were obtained from 14 sites from each subject. Forty subgingival taxa were quantified using checkerboard DNA-DNA hybridization and the concentrations of eight GCF cytokines were measured using Luminex. Cluster analysis was used to define sites with similar subgingival microbiotas in each clinical group. Significance of differences in clinical, microbiological and immunological parameters among clusters was determined using the Kruskal-Wallis test. RESULTS:GAP subjects had statistically significantly higher GCF levels of interleukin-1beta (IL-1beta) (p<0.001), granulocyte-macrophage colony-stimulating factor (GM-CSF) (p<0.01) and IL-1beta/IL-10 ratio (p<0.001) and higher proportions of Red and Orange complex species than periodontally healthy subjects. There were no statistically significant differences in the mean proportion of cytokines among clusters in the periodontally healthy subjects, while the ratio IL-1beta/IL-10 (p<0.05) differed significantly among clusters in the aggressive periodontitis group. CONCLUSIONS:Different subgingival biofilm profiles are associated with distinct patterns of GCF cytokine expression. Aggressive periodontitis subjects were characterized by a higher IL-1beta/IL-10 ratio than periodontally healthy subjects, suggesting an imbalance between pro- and anti-inflammatory cytokines in aggressive periodontitis.

BACKGROUND:This study determines the gingival crevicular fluid (GCF) levels of interleukin (IL)-1 beta, IL-2, IL-4, IL-8, interferon (IFN)-gamma and elastase activity in inflamed shallow and deep periodontal sites from patients with generalized chronic (GCP) and generalized aggressive periodontitis (GAgP), and to compare them to shallow sites from subjects with gingivitis. A secondary aim analyzes the microbiologic profile of these subjects.METHODS:Cross-sectional clinical data were obtained from 20 GCP, 17 GAgP, and 10 gingivitis subjects. GCF samples were collected with paper strips and the levels of IL-1 beta, IL-2, IL-4, IL-8, and IFN-gamma were measured using a multiplexed bead immunoassay. Elastase activity was assessed by an enzymatic assay. Subgingival plaque samples were analyzed using checkerboard DNA-DNA hybridization. Significance of differences among groups for immunologic and microbiologic data was examined using Kruskal-Wallis adjusting for multiple comparisons.RESULTS:Mean clinical parameters and GCF volumes were higher in patients with GCP and GAgP compared to the gingivitis group. Higher levels of IL-1 beta and higher elastase activity were found in deep sites compared to shallow sites in both periodontitis groups (P <0.05). The microbiologic data showed significantly higher levels of the red complex species in patients with GCP and GAgP compared to gingivitis (P <0.05). There were no statistically significant differences in levels of GCF biomarkers and in levels of subgingival bacterial species between subjects with GCP and GAgP.CONCLUSION:There were no statistically significant differences in the measured immunologic and microbiologic parameters between subjects with GCP and GAgP.

PURPOSE Previous studies have shown the relationship of individual clinical variables to the survival of Dicor (Corning Glass Works) restorations. The purpose of the present investigation was to examine the effect of combinations of these variables on the intraoral survival of Dicor restorations. MATERIALS AND METHODS Dicor glass-ceramic restorations (n=1,444) were placed in 417 adult patients. Failure was defined as a restoration that required remake because of material fracture. The survival of restorations with different combinations of variables that were each individually associated with survival was described using Kaplan-Meier survivor functions. The statistical significance of differences in survival between different combinations of specific predictor variables was examined using the proportional hazards model. RESULTS Kaplan-Meier survival analysis indicated that significantly worse survival rates were found for restorations that included combinations of molar teeth, a dentin core, and a glass-ionomer luting agent; molar teeth, a dentin core, and a resin luting agent; and single-rooted teeth, a dentin core, and a glass-ionomer luting agent than for any other combinations tested. The Cox proportional hazards model described a hazard ratio of 3.37 (95% confidence interval [CI]: 2.23 to 5.08) for molar teeth (versus single-rooted teeth), 2.65 (95% CI: 1.44 to 4.87) for dentin core (versus gold core), 2.35 (95% CI: 1.58 to 3.51) for men (versus women), and 1.72 (95% CI: 1.13 to 2.60) for glass-ionomer luting agent (versus resin) after adjusting for the other variables in the model. CONCLUSION Factors beyond individual restoration design impact the survival of Dicor glass-ceramic. These include sex, tooth position, and restorations luted to gold core foundation bases.

BACKGROUND/AIM:The purpose of the present investigation was to examine subgingival microbial profiles associated with refractory periodontitis and to seek such profiles in periodontally healthy, periodontally well-maintained elder and untreated periodontitis subjects.METHODS:36 subjects were defined as refractory on the basis of further attachment loss after scaling and root planing, surgery and systemically administered antibiotics. A total of 890 subgingival plaque samples (mean/subject=24.7) were taken from the mesial aspect of each tooth in each subject at baseline and individually processed for their content of 40 subgingival taxa using checkerboard DNA-DNA hybridization. Cluster analysis was performed on mean within subject species counts using the chord coefficient and an average unweighted linkage sort. Significant differences among clusters for individual and complexes of species were sought using the Kruskal Wallis test. The microbial profiles of the refractory subjects were compared with those of 27 periodontally healthy subjects (n plaque samples=708), 35 periodontally well-maintained elder subjects (n plaque samples=801) and 115 untreated adult periodontitis subjects (n plaque samples=2871).RESULTS:28 of 36 refractory subjects fell into 4 clusters with >29% similarity. 10 of 40 species and 4 of 7 complexes differed significantly among clusters. Profile (Cluster) I (n=4) was characterized by high proportions of "yellow" and "green" complex species, profile II (n=3) by low total counts and high proportions of "orange" and "purple" complex species, profile III (n=9) by high total counts and counts of Actinomyces and "purple" complex species, profile IV (n=12) by high proportions of "red" and "orange" complex species. The mean profiles of each cluster were subjected to cluster analysis with microbial data from 4380 (mean 24.7) baseline subgingival plaque samples from 27 periodontally healthy, 35 treated, well-maintained elders and 115 untreated adult periodontitis subjects. 12 clusters were formed with >41% similarity. 3 of the refractory profiles were detected in 3 cluster groups. Profile II in a cluster of 1 healthy, 1 elder and 4 untreated periodontitis subjects; profile III in a cluster of 1 healthy, 2 elder and 12 periodontitis subjects; Profile IV, with 1 healthy and 5 untreated periodontitis subjects. The profile not detected in non refractory subjects was dominated by Streptococcus species. 9 clusters did not harbor refractory profiles. 11.1% of healthy, 8.6% of elder and 18.3% of periodontitis subjects were in clusters exhibiting refractory microbial profiles.CONCLUSIONS:4 subgingival microbial profiles were detected among refractory subjects. "Refractory microbial profiles" could be detected in subjects who had not yet exhibited refractory disease.

OBJECTIVE:The purpose of the present investigation was to determine if antimicrobial mouthrinses with different formulations could affect the composition of the subgingival microbiota and clinical parameters of adjacent tissues in periodontal maintenance subjects.METHODS:One-hundred and sixteen subjects, who had been treated for chronic periodontitis and were in a maintenance program, were randomly assigned one of four mouthrinses, to be used twice daily for three months. The mouthrinses were herbal 1, herbal 2, essential oil, and chlorhexidine. Clinical measurements and subgingival plaque samples were taken at baseline and at three months. Plaque samples were individually evaluated for 18 test species/taxa using checkerboard DNA-DNA hybridization. Significance of differences between baseline and three months for both microbiological and clinical parameters were determined using the Wilcoxon Signed Ranks test. Significance of difference among groups for change in clinical and microbiological parameters was determined using analysis of covariance (ANCOVA), adjusting for baseline values.RESULTS:Shifts in species proportions differed significantly for 9/18 test species/taxa among the four mouthrinse groups. Streptococcus and Capnocytophaga species were reduced most in the herbal rinse groups, while Veillonella parvula was reduced most in the essential oil and chlorhexidine groups. Actinomyces were also markedly reduced in the chlorhexidine group. Mean Plaque (PI) and Gingival Indices (GI) were reduced between baseline and three months in each group. Results emphasize that chlorhexidine (p < 0.001) and herbal (p < 0.05) rinses significantly reduced PI. Some subjects in each group responded better than others.CONCLUSION:All four mouthrinses tested produced shifts in the composition of subgingival microbiota, although the results differed among the groups. The observed microbial changes were accompanied by improvements in clinical parameters in the periodontal maintenance subjects.

AIM:To compare polymerase chain reaction (PCR) with subsequent reverse hybridization (micro-IDent test) and checkerboard DNA-DNA hybridization for the identification of 13 bacterial species in subgingival plaque samples. MATERIAL AND METHODS:Subgingival plaque samples were taken using paper points and curettes from two sites each with pocket depth <4, 4-6 and >6 mm at baseline and 3 months in 25 periodontitis subjects and two sites in 25 periodontally healthy subjects. Samples were analysed for their content of 13 bacterial species using both assays. Similarities for each species between techniques were determined using regression analysis. Differences between health and periodontitis were determined using the Mann-Whitney test. RESULTS:Three hundred and fifty samples were evaluated using both techniques. Regression analysis indicated that 10/13 test species showed significant positive correlations between the counts determined by checkerboard analysis and levels determined by the PCR-based test after adjusting for 13 comparisons. The highest rank correlations of 0.58, 0.49 and 0.46 were seen for Treponema denticola, Fusobacterium nucleatum and Eubacterium nodatum, respectively (p<0.0001). Both tests could distinguish samples from healthy and periodontitis subjects. CONCLUSION:Detection patterns of 10/13 test species in subgingival plaque samples from periodontitis and healthy subjects were similar using the two molecular techniques.