Evaluation of the Microbial Profile on the Polydioxanone Membrane and the Collagen Membrane Exposed to Multi-Species Subgingival Biofilm: An In Vitro Study.

Dehiscence in surgeries involving membranes often leads to bacterial contamination, hindering the healing process. This study assessed bacterial colonization on various membrane materials. Polydioxanone (PDO) membranes, with thicknesses of 0.5 mm and 1 mm, and a collagen membrane were examined. Packages containing polystyrene pins were crafted using these membranes, attached to 24-well plates, and exposed to oral bacteria from supra and subgingival biofilm. After a week's anaerobic incubation, biofilm formation was evaluated using the DNA-DNA hybridization test. Statistical analysis employed the Kruskal-Wallis test with Dunn's post hoc test. The biofilm on the polystyrene pins covered by the 0.5 mm PDO membrane showed a higher count of certain pathogens. The collagen membrane had a greater total biofilm count on its inner surface compared to both PDO membranes. The external collagen membrane face had a higher total biofilm count than the 0.5 mm PDO membrane. Furthermore, the 1 mm PDO membrane exhibited a greater count of specific pathogens than its 0.5 mm counterpart. In conclusion, the collagen membrane presented more biofilm and pathogens both internally and on its inner surface.

Newly identified pathogens in periodontitis: evidence from an association and an elimination study.

We assessed the level of evidence for the presence of new periodontal pathogens by (i) comparing the occurrence of non-classical periodontal taxa between healthy vs. periodontitis patients (Association study); (ii) assessing the modifications in the prevalence and levels of these species after treatments (Elimination study). In the Association study, we compared the prevalence and levels of 39 novel bacterial species between periodontally healthy and periodontitis patients. In the Elimination study, we analyzed samples from periodontitis patients assigned to receive scaling and root planing alone or with metronidazole+ amoxicillin TID/ 14 days. Levels of 79 bacterial species (39 novel and 40 classic) were assessed at baseline, 3 and 12 months post-therapy. All samples were analyzed using Checkerboard DNA-DNA hybridization. Out of the 39 novel species evaluated, eight were categorized as having strong and four as having moderate association with periodontitis. Our findings suggest strong evidence supporting Lancefieldella rimae, Cronobacter sakazakii, Pluralibacter gergoviae, Enterococcus faecalis, Eubacterium limosum, Filifactor alocis, Haemophilus influenzae, and Staphylococcus warneri, and moderate evidence supporting Escherichia coli, Fusobacterium necrophorum, Spiroplasma ixodetis, and Staphylococcus aureus as periodontal pathogens. These findings contribute to a better understanding of the etiology of periodontitis and may guide future diagnostic and interventional studies.

Patients with type 2 diabetes and severe periodontitis harbor a less pathogenic subgingival biofilm than normoglycemic individuals with severe periodontitis.

BACKGROUND: Whether, and to what extent, diabetes mellitus (DM) can affect the subgingival biofilm composition remains controversial. Thus, the aim of this study was to compare the composition of the subgingival microbiota of non-diabetic and type 2 diabetic patients with periodontitis using 40 "biomarker bacterial species." METHODS: Biofilm samples of shallow (probing depth [PD] and clinical attachment level [CAL] ≤3 mm without bleeding) and deep sites (PD and CAL ≥5 mm with bleeding) of patients with or without type 2 DM were evaluated for levels/proportions of 40 bacterial species by checkerboard DNA-DNA hybridization. RESULTS: A total of 828 subgingival biofilm samples from 207 patients with periodontitis (118 normoglycemic and 89 with type 2 DM) were analyzed. The levels of most of the bacterial species evaluated were reduced in the diabetic compared with the normoglycemic group, both in shallow and in deep sites. The shallow and deep sites of patients with type 2 DM presented higher proportions of Actinomyces species, purple and green complexes, and lower proportions of red complex pathogens than those of normoglycemic patients (P < 0.05). CONCLUSIONS: Patients with type 2 DM have a less dysbiotic subgingival microbial profile than normoglycemic patients, including lower levels/proportions of pathogens and higher levels/proportions of host-compatible species. Thus, type 2 diabetic patients seem to require less remarkable changes in biofilm composition than non-diabetic patients to develop the same pattern of periodontitis.

Do the progression of experimentally induced gingivitis and peri-implant mucositis present common features? A systematic review of clinical human studies.

This systematic review evaluated the features of the progression of experimentally induced gingivitis and peri-implant mucositis in humans. Included were studies that evaluated clinical, immunological, or microbiological responses between experimentally induced gingivitis and peri-implant mucositis in periodontally healthy patients. A total of 887 articles were initially identified, but only 12 were included in the final analysis. Implants accumulate less biofilm and suffer the most heterogeneous alterations in the microbiota, in the abstinence of oral hygiene, compared with the tooth. Interestingly, although dental implants presented less biofilm accumulation, the peri-implant mucosa showed a more exacerbated clinical response than the gingival tissue. The risk of bias of the selected studies was moderate to low, with one study presenting serious risk. The progression events of peri-implant mucositis were similar to those of experimental gingivitis but led to a different host response. This review was registered in the PROSPERO database CRD420201 123360.

Adverse events of metronidazole and amoxicillin: Retrospective analysis of a large data set of five randomized clinical trials.

AIM: To evaluate the frequency of side effects associated with intake of metronidazole (MTZ) + amoxicillin (AMX) in periodontal treatment, and to explore associations between these events and patients' features. MATERIALS AND METHODS: Data of five randomized clinical trials testing MTZ + AMX adjunctive to mechanical therapy were evaluated. Volunteers answered an adverse event questionnaire. RESULTS: Information from 656 subjects was assessed. The frequency of side effects in the antibiotic- and placebo-treated groups ranged from 1.0% to 17.7% and 0.9% to 13.7%, respectively. The events more frequently observed in the antibiotic than in the placebo group were diarrhoea and metallic taste (p < .05). Diabetes significantly raised the odds of a patient reporting discomfort (odds ratio [OR] = 2.6), diarrhoea (OR = 4.0), weakness (OR = 6.0) and excessive sleepiness (OR = 2.9). In systemically healthy volunteers, using antibiotics 3 months post-mechanical treatment (healing phase) (OR = 3.0), being a woman (OR = 3.9) and aged ≤49 (OR = 4.5) significantly increased the chances of reporting adverse events. CONCLUSIONS: The occurrence of side effects during MTZ + AMX treatment ranged from uncommon (1%) to very common (17.7%). The main factors raising the chances of a patient reporting adverse events were diabetes and taking antibiotics in the healing phase, instead of in the active phase of treatment. Patients ≤ 49 years old and females also tend to report more side effects.

Systematic and scoping reviews to assess biological parameters.

INTRODUCTION: An evidence synthesis approach compiling biological/laboratory data is effective in advancing health-related knowledge. However, this approach is still underused in the oral health field. METHODS: This commentary discusses the opportunities and challenges of systematic and scoping reviews of laboratory data in dentistry. Special focus is on the potential of these reviews to elucidate etiological and treatment concepts of oral diseases, such as periodontitis and peri-implantitis. RESULTS: The following difficulties associated with such studies are discussed: (i) selection of ideal study design, (ii) assessment of "risk of bias" and definition of "certainty of evidence", (iii) evidence assembly and summary, and (iv) the paper review process. DISCUSSION: Despite those challenges, high-quality reviews integrating laboratory data may generate relevant scientific information and help identify new avenues for future investigations. Experts in different oral health topics should build a process capable of helping researchers assemble and interpret these types of data.

Decontamination and Biomodification of Periodontally Affected Root Surface for Successful Regeneration: Is There Room for Improvement?

Periodontitis is a multifactorial inflammatory condition associated with an oral microbiome dysbiosis that results in gingival inflammation and clinical attachment loss. Periodontal therapies are based on scaling and root planing to disturb the bacterial biofilm mechanically and remove calculus and contaminated cementum. Research does not support the use of root modifiers for decontamination and biomodification of periodontally affected root surfaces. Standardized clinical trials in large populations, assessing biological and patient-reported outcome measures, are necessary to evaluate candidate biomaterials for decontamination and biomodification of periodontally affected root surfaces.

The impact of predatory bacteria on experimental periodontitis.

BACKGROUND: This study evaluated the effects of topical administration of Bdellovibrio bacteriovorus HD100 on experimental periodontitis (EP) in rats. METHODS: Thirty-two rats were divided into groups C (control), EP, C-HD100, and EP-HD100. At day 0, animals of groups EP and EP-HD100 received cotton ligatures around mandibular first molars (MFM). In groups C-HD100 and EP-HD100, 1 mL of suspensions containing B. bacteriovorus HD100 was topically administered in the subgingival region of MFMs at days 0, 3, and 7. Animals were euthanized at day 14. Gingival tissue, hemimandibles, and oral biofilm were collected. Data were statistically analyzed. RESULTS: Group EP-HD100 presented greater bone volume and lower connective tissue attachment loss (CTAL) than group EP (P < 0.05). Group EP-HD100 presented greater proportions of Actinomyces and Streptococcus-like species and lower proportions of Prevotella intermedia, Peptostreptococcus micros, Fusobacterium nucleatum, Fusobacterium polymorphum, Eikenella corrodens, Eubacterium nodatum, Campylobacter gracilis, Capnocytophaga sputigena, and Veillonella parvula-like species than group EP. Group EP-HD100 presented greater levels of osteoprotegerin and gene expression of interleukin (IL)-17, IL-10, and forkhead box P3 than group EP (P < 0.05). CONCLUSION: Topical use of B. bacteriovorus HD100 promotes a protective effect against alveolar bone loss and CTAL in rats with EP.

Support vector machine-based differentiation between aggressive and chronic periodontitis using microbial profiles.

BACKGROUND: The existence of specific microbial profiles for different periodontal conditions is still a matter of debate. The aim of this study was to test the hypothesis that 40 bacterial species could be used to classify patients, utilising machine learning, into generalised chronic periodontitis (ChP), generalised aggressive periodontitis (AgP) and periodontal health (PH). METHOD: Subgingival biofilm samples were collected from patients with AgP, ChP and PH and analysed for their content of 40 bacterial species using checkerboard DNA-DNA hybridisation. Two stages of machine learning were then performed. First of all, we tested whether there was a difference between the composition of bacterial communities in PH and in disease, and then we tested whether a difference existed in the composition of bacterial communities between ChP and AgP. The data were split in each analysis to 70% train and 30% test. A support vector machine (SVM) classifier was used with a linear kernel and a Box constraint of 1. The analysis was divided into two parts. RESULTS: Overall, 435 patients (3,915 samples) were included in the analysis (PH = 53; ChP = 308; AgP = 74). The variance of the healthy samples in all principal component analysis (PCA) directions was smaller than that of the periodontally diseased samples, suggesting that PH is characterised by a uniform bacterial composition and that the bacterial composition of periodontally diseased samples is much more diverse. The relative bacterial load could distinguish between AgP and ChP. CONCLUSION: An SVC classifier using a panel of 40 bacterial species was able to distinguish between PH, AgP in young individuals and ChP.

Oral Streptococci Biofilm Formation on Different Implant Surface Topographies.

The establishment of the subgingival microbiota is dependent on successive colonization of the implant surface by bacterial species. Different implant surface topographies could influence the bacterial adsorption and therefore jeopardize the implant survival. This study evaluated the biofilm formation capacity of five oral streptococci species on two titanium surface topographies. In vitro biofilm formation was induced on 30 titanium discs divided in two groups: sandblasted acid-etched (SAE- n = 15) and as-machined (M- n = 15) surface. The specimens were immersed in sterilized whole human unstimulated saliva and then in fresh bacterial culture with five oral streptococci species: Streptococcus sanguinis, Streptococcus salivarius, Streptococcus mutans, Streptococcus sobrinus, and Streptococcus cricetus. The specimens were fixed and stained and the adsorbed dye was measured. Surface characterization was performed by atomic force and scanning electron microscopy. Surface and microbiologic data were analyzed by Student's t-test and two-way ANOVA, respectively (P < 0.05). S. cricetus, S. mutans, and S. sobrinus exhibited higher biofilm formation and no differences were observed between surfaces analyzed within each species (P > 0.05). S. sanguinis exhibited similar behavior to form biofilm on both implant surface topographies, while S. salivarius showed the lowest ability to form biofilm. It was concluded that biofilm formation on titanium surfaces depends on surface topography and species involved.

Systemic antibiotics in the treatment of aggressive periodontitis. A systematic review and a Bayesian Network meta-analysis.

AIM: The aim of this study was to assess the effect of systemic antibiotic therapy on the treatment of aggressive periodontitis (AgP). METHODS: This study was conducted and reported in accordance with the PRISMA statement. The MEDLINE, EMBASE and CENTRAL databases were searched up to June 2014 for randomized clinical trials comparing the treatment of subjects with AgP with either scaling and root planing (SRP) alone or associated with systemic antibiotics. Bayesian network meta-analysis was prepared using the Bayesian random-effects hierarchical models and the outcomes reported at 6-month post-treatment. RESULTS: Out of 350 papers identified, 14 studies were eligible. Greater gain in clinical attachment (CA) (mean difference [MD]: 1.08 mm; p < 0.0001) and reduction in probing depth (PD) (MD: 1.05 mm; p < 0.00001) were observed for SRP + metronidazole (Mtz), and for SRP + Mtz + amoxicillin (Amx) (MD: 0.45 mm, MD: 0.53 mm, respectively; p < 0.00001) than SRP alone/placebo. Bayesian network meta-analysis showed additional benefits in CA gain and PD reduction when SRP was associated with systemic antibiotics. CONCLUSIONS: SRP plus systemic antibiotics led to an additional clinical effect compared with SRP alone in the treatment of AgP. Of the antibiotic protocols available for inclusion into the Bayesian network meta-analysis, Mtz and Mtz/Amx provided to the most beneficial outcomes.

Systemic antibiotics in the treatment of periodontitis.

Despite the fact that several clinical studies have shown additional benefits when certain systemic antibiotics are used as adjuncts to periodontal treatment, clear guidelines for the use of these agents in the clinical practice are not yet available. Basic questions concerning the use of systemic antibiotics to treat periodontitis remain unanswered, such as: which drug(s) should be used; which patients would most benefit from treatment; which are the most effective protocols (i.e. doses and durations); and in which phase of the mechanical therapy should the drug(s) be administered? Although not all of those questions have been directly addressed by controlled randomized clinical trials, recent concepts related to the ecology of periodontal diseases, as well as the major advances in laboratory and clinical research methods that have occurred in the past decade, have significantly broadened our knowledge in this field. This article endeavored to provide a 'state of the art' overview on the use of systemic antibiotics in the treatment of periodontitis, based on the most recent literature on the topic as well as on a compilation of data from studies conducted at the Center of Clinical Trials at Guarulhos University (São Paulo, Brazil) from 2002 to 2012.

Metronidazole alone or with amoxicillin as adjuncts to non-surgical treatment of chronic periodontitis: a secondary analysis of microbiological results from a randomized clinical trial.

AIM: To 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. METHODS: One hundred and eighteen subjects were randomly assigned to receive 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% CHX twice a day (BID) for 2 months. Nine subgingival plaque samples/subject were analysed by checkerboard DNA­DNA hybridization for 40 bacterial species at baseline, 3, 6 and 12 months post-therapy. RESULTS: At 12 months, 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 12 months. CHX rinsing enhanced the microbiological effects of the MTZ + AMX treatment in shallow sites. CONCLUSION: The 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.

Stability of implants placed in augmented posterior mandible after alveolar osteotomy using resorbable nonceramic hydroxyapatite or intraoral autogenous bone: 12-month follow-up.

PURPOSE: This prospective, controlled split-mouth study evaluated the stability of dental implants placed in the augmented mandibular areas with alveolar segmental "sandwich" osteotomies using nonceramic hydroxyapatite (ncHA) or autogenous bone. MATERIAL AND METHODS: This study included 11 bilaterally partially edentulous mandibular patients in a split-mouth design. Alveolar augmentation osteotomies were performed bilaterally with interpositional ncHA graft (test group) or interpositional intraoral autogenous bone graft (control group). After 6 months of healing, four implants (two implants in each side) were placed in each patient. Forty-four implants were inserted and loaded after 6-month healing period. At 1-year follow-up, radiographic, prosthetic, and resonance frequency analysis parameters were assessed. Success criteria included absence of pain, sensitivity, suppuration, and implant mobility; absence of continuous peri-implant radiolucency; and distance between the implant shoulder and the first visible bone contact (DIB) < 2 mm. RESULTS: After a 1-year loading period, the overall implant survival rate was 95.45%, with two implant losses (one of each group). Among the surviving implants (42 out of 44), two did not fulfill the success criteria; therefore, the implant success was 90.90%. DIB was 0.71 ± 0.70 and 0.84 ± 0.72 mm for ncHA and autogenous bone grafts, respectively (p > .05). Implant stability measurements were similar between the groups during the 12-month follow-up (p > .05). CONCLUSION: Within the limits of this study, the implants placed either in sites augmented with ncHA or autogenous bone seem to represent a safe and successful procedure, at least, after 12-month follow-up.

Microbiological diversity of peri-implantitis biofilm by Sanger sequencing.

BACKGROUND AND OBJECTIVE: To examine the microbial diversity associated with implants with or without peri-implantitis and to identify differences between the bacterial communities in these clinical conditions. MATERIAL AND METHODS: Twenty subjects were assigned to a Control group consisting of subjects with healthy implants and a Test group consisting of subjects with peri-implantitis sites, as well as a healthy implant site (n = 10/group). In the Test group, subgingival biofilm samples were taken from the deepest sites of the diseased implant. In both groups, samples were collected from one site around a healthy implant. DNA was extracted and the 16S rRNA gene was amplified and sequenced, and the phylotypes were identified by comparison with known 16S rRNA sequences. RESULTS: The phylogenetic identity of 1387 16S rRNA gene clones was determined. Healthy implants demonstrated higher proportions of Actinomyces, Atopobium, Gemella, Kingella and Rothia and lower levels of Campylobacter, Desulfobulbus, Dialister, Eubacterium, Filifactor, Mitsukella, Porphyromonas and Pseudoramibacter (Mann-Whitney U-test; P < 0.05). Fusobacterium nucleatum, Dialister invisus, Streptococcus sp. human oral taxon (HOT) 064, Filifactor alocis and Mitsuokella sp. HOT 131 presented a higher mean proportion, while Veillonella dispar, Actinomyces meyeri, Granulicatella adiacens showed lower mean proportions in the peri-implantitis sites when compared with healthy implants in both the Control and Test groups (Mann-Whitney U-test; P < 0.05). CONCLUSION: Marked differences were observed in the composition of the subgingival biofilm between healthy and diseased implants. The biofilm associated with peri-implantitis harbored more pathogenic bacterial species from the orange complex and other "unusual" putative pathogens, such as F. alocis, D. invisus and Mitsuokella sp. HOT 131.

Full-mouth disinfection as a therapeutic protocol for type-2 diabetic subjects with chronic periodontitis: twelve-month clinical outcomes: a randomized controlled clinical trial.

AIM: The aim of this randomized controlled clinical trial was to evaluate the clinical effects of chlorhexidine (CHX) application in a full-mouth disinfection (FMD) protocol in poorly controlled type-2 diabetic subjects with generalized chronic periodontitis. MATERIAL AND METHODS: Thirty-eight subjects were randomly assigned into FMD group (n=19): full-mouth scaling and root planing (FMSRP) within 24 h + local application of CHX gel + CHX rinses for 60 days or Control group (n = 19): FMSRP within 24 h + local application of placebo gel + placebo rinses for 60 days. Clinical parameters, glycated haemoglobin and fasting plasma glucose were assessed at baseline, 3, 6 and 12 months post-therapies. RESULTS: All clinical parameters improved significantly at 3, 6 and 12 months post-therapies for both groups (p < 0.05). There were no significant differences between groups for any clinical parameters, and glycemic condition at any time-point (p > 0.05). CONCLUSIONS: The treatments did not differ with respect to clinical parameters, including the primary outcome variable (i.e. changes in clinical attachment level in deep pockets), for up to 12 months post-treatments.

The effects of adjunctive metronidazole plus amoxicillin in the treatment of generalized aggressive periodontitis: a 1-year double-blinded, placebo-controlled, randomized clinical trial.

AIM: To evaluate the clinical effects of the adjunctive use of metronidazole (MTZ) and amoxicillin (AMX) in the treatment of generalized aggressive periodontitis (GAgP). METHODS: Thirty subjects were randomly assigned to receive scaling and root planing (SRP) alone or combined with MTZ (400 mg/TID) and AMX (500 mg/TID) for 14 days. Subjects were clinically monitored at baseline, 6 months and 1 year post-therapies. RESULTS: Both therapies led to a statistically significant improvement in all clinical parameters at 1 year post-therapy (p < 0.05). Subjects receiving MTZ plus AMX exhibited the deepest reductions in mean probing depth (PD) and gain in clinical attachment between baseline and 1 year post-therapy in the full-mouth analysis and in initially intermediate (PD 4-6 mm) and deep (PD ≥ 7 mm) sites (p < 0.01). In addition, the antibiotic group presented lower mean number of residual sites with PD ≥ 5 or 6 mm as well as fewer subjects still presenting nine or more sites with PD ≥ 5 mm or three or more sites with PD ≥ 6 mm at the end of the study period. CONCLUSION: The non-surgical treatment of GAgP is markedly improved by the adjunctive use of MTZ+AMX, up to 1 year post-treatment.

Antimicrobial photodynamic therapy in the non-surgical treatment of aggressive periodontitis: microbiological profile.

The aim of this trial was to investigate changes occurring in the subgingival microbiological composition of subjects with aggressive periodontitis, treated with antimicrobial photodynamic therapy (aPDT), in a single episode, or scaling and root planing (SRP), in a split-mouth design on -7, 0, and +90 days. Ten patients were randomly assigned to either aPDT using a laser source in conjunction with a photosensitizer or SRP with hand instruments. Subgingival plaque samples were collected and the counts of 40 subgingival species were determined using checkerboard DNA-DNA hybridization. The data were analyzed using the method of generalized estimating equations (GEE) to test the associations between treatments, evaluated parameters, and experimental times (α = .05). The results indicated that aPDT and SRP affects different bacterial species, with aPDT being effective in reducing numbers of A. actinomycetemcomitans than SRP. On the other hand, SRP was more efficient than aPDT in reducing the presence of periodontal pathogens of the Red Complex. Additionally, a recolonization in the sites treated by aPDT was observed, especially for T. forsythia and P. gingivalis. Under our experimental conditions, this trial demonstrates that aPDT and SRP affected different groups of bacteria, suggesting that their association may be beneficial for the non-surgical treatment of aggressive periodontitis.

Phenomenon of laser power loss during curettage of infected periodontal pockets.

OBJECTIVE: The purpose of this study was to evaluate the reduction in laser power output (PO) at the optical fiber tip during laser curettage of infected periodontal pockets. BACKGROUND DATA: The combination of mechanical debridement with laser therapy has been used successfully in the treatment of periodontitis. METHODS: The study group consisted of 28 teeth selected in 12 patients with chronic periodontitis. The teeth were treated with scaling and root planing (SRP), and infected pocket epithelium was removed with an 810-nm diode laser operating at a laser power of 1.7 W in continuous-wave mode (CW). Laser power was set to 1.0 W at the control panel before each measurement to facilitate mathematical analysis, and PO at the optical fiber tip was measured using a power meter. Four laser applications were performed per tooth (duration, 10-15 sec per application; total duration, 40-60 sec per tooth). The fiber tip was cleaved every four applications. Also, 28 irradiations (four PO measurements per irradiation) were performed in non-contact mode and used as controls. RESULTS: There were significant PO losses between applications in the study group. PO losses of 20.89%, 30.39%, and 40.26% were found between the first and second, first and third, and first and fourth applications, respectively. A low transmission loss of the optical fiber was observed in the control measurements (mean PO loss of 1.58% between the first and fourth irradiations). CONCLUSIONS: Our results indicated that optical fiber tips need to be cleaved frequently during laser curettage to minimize PO loss.

Quantification of Porphyromonas gingivalis and fimA genotypes in smoker chronic periodontitis.

AIM: Porphyromonas gingivalis fimA genotypes were associated with virulence factors in vitro, but little evidence of an association with disease severity were shown in humans. We aimed to correlate levels of P. gingivalis fimA genotypes II and IV and probing depth in smoker-chronic periodontitis subjects. MATERIAL AND METHODS: One hundred and sixty eight subgingival samples of 20 smokers non-treated chronic periodontitis subjects obtained from sites with different probing depths [shallow (< or =3 mm), intermediate (4-6 mm), deep (> or =7 mm)] were analysed by real-time PCR for P. gingivalis and genotypes fimA II and IV. RESULTS: P. gingivalis and fimA IV were detected in all subjects, whereas fimA II was detected in 18 subjects (90%). One hundred and fifty two sites (90.5%) harboured P. gingivalis. Genotypes II and IV were detected in 28% and 69.6% of sites, respectively. The proportions of genotypes II and IV in relation to P. gingivalis levels were similar in shallow, intermediate and deep probing sites (2.4%, 4.6%, 1.4% for genotype II and 15.5%, 17.7%, 11.7% for genotype IV, respectively), indicating that other non-tested genotypes were more abundant. Increased levels of genotype IV were associated with increasing probing depth, but not of genotype II. CONCLUSIONS: The data suggested an association between P. gingivalis genotype fimA IV and disease severity in smoker-chronic periodontitis subjects.