Effects of different periodontal treatments in changing the prevalence and levels of Archaea present in the subgingival biofilm of subjects with periodontitis: A secondary analysis from a randomized controlled clinical trial.

OBJECTIVE: The aim of this randomized double-blind and placebo-controlled study was to assess if periodontal treatment with or without systemic antibiotic would change the mean level of Archaea. METHODS: Fifty-nine (59) subjects were randomly assigned to receive scaling and root planing (SRP) alone or combined with metronidazole (MTZ; 400 mg/TID) or either with MTZ and amoxicillin (AMX; 500 mg/TID) for 14 days. Clinical and microbiological examinations were performed at baseline and at 6 months post-SRP. Six subgingival plaque samples per subject were analysed for the presence and levels of Archaea using quantitative polymerase chain reaction. RESULTS: Scaling and root planing alone or combined with MTZ or MTZ + AMX significantly reduced the prevalence of subjects colonized by Archaea at 6 months post-therapy, without significant differences among groups (P > .05). Both therapies led to a statistically significant decrease in the mean percentage of sites colonized by Archaea (P < .05). The MTZ and MTZ + AMX group had a significantly lower mean number of sites colonized by Archaea and lower levels of these micro-organisms at sites with probing depth ≥5 mm at 6 months compared with SRP group (P < .05). CONCLUSION: Periodontal treatments including adjunctive MTZ or MTZ + AMX are more effective than mechanical treatment alone in reducing the levels and prevalence of sites colonized by Archaea in subjects with chronic periodontitis.

Diabetes may affect the expression of matrix metalloproteinases and their inhibitors more than smoking in chronic periodontitis.

BACKGROUND AND OBJECTIVE: No previous study has directly compared the levels of matrix metalloproteinases (MMPs) and tissue inhibitor of metalloproteinases (TIMPs) between smokers and individuals with diabetes mellitus (DM) with periodontitis. Therefore, the aim of this study was to evaluate the gene expression of MMP-1, MMP-2, MMP-8, MMP-9, TIMP-1 and TIMP-2 in tissues with chronic periodontitis (ChP) of smokers and individuals with type 2 DM. MATERIAL AND METHODS: Gingival biopsies were harvested from: non-smokers and non-diabetic individuals with ChP (n = 18) (ChP group); non-diabetic smokers (≥ 10 cigarettes per day for at least the past 5 years) with ChP (n = 18) (SChP group); non-smoking individuals with type 2 diabetes (glycated hemoglobin levels ≥ 7.5%) and ChP (n = 18) (DMChP group). The tissue levels of mRNA of MMP-1, MMP-2, MMP-8, MMP-9, TIMP-1 and TIMP-2 were evaluated by quantitative real-time polymerase chain reaction. RESULTS: The MMP-8 expression was the lowest in the ChP group (p < 0.05). The DMChP group presented increased mRNA levels of MMP-2 and MMP-9, when compared to the SChP group (p < 0.05). MMP-1 expression and the MMP-1/TIMP-1, MMP-2/TIMP-1, MMP-8/TIMP-1, MMP-9/TIMP-1, MMP-1/TIMP-2 and MMP-2/TIMP-2 ratios were higher in the DMChP group than in the ChP and SChP groups (p < 0.05). The DMChP group presented lower mRNA levels of TIMP-1 than the ChP group (p < 0.05). The MMP-8/TIMP-2 ratio was the highest in the SChP group (p < 0.05). CONCLUSION: Uncontrolled type 2 DM upregulates the ratio of MMP/TIMPs in sites with ChP more than smoking, which may contribute to a greater extracellular matrix degradation and periodontal breakdown in DM-related periodontitis.

Levels of Candidate Periodontal Pathogens in Subgingival Biofilm.

In recent years, several new periodontal taxa have been associated with the etiology of periodontitis. A recent systematic review provides further support for the pathogenic role of 17 species/phylotypes. Thus, the aim of this study was to assess the prevalence and levels of these species in subjects with generalized chronic periodontitis (GChP; n = 30), generalized aggressive periodontitis (GAgP; n = 30), and periodontal health (PH; n = 30). All subjects underwent clinical and microbiological assessment. Nine subgingival plaque samples were collected from each subject and analyzed for their content of 20 bacterial species/phylotypes through the RNA-oligonucleotide quantification technique. Subjects from the GChP and GAgP groups presented the highest mean values for all clinical parameters in comparison with the PH group (P < 0.05). Subjects with GChP and GAgP showed significantly higher mean levels of Bacteroidetes sp. human oral taxon (HOT) 274, Fretibacterium sp. HOT 360, and TM7 sp. HOT 356 phylotypes, as well as higher mean levels of Filifactor alocis, Fretibacterium fastidiosum, Porphyromonas gingivalis, Tannerella forsythia, and Selenomonas sputigena species than PH subjects (P < 0.05). GAgP subjects presented higher mean levels of TM7 sp. HOT 356 and F. alocis than GChP subjects (P < 0.05). A significantly higher mean prevalence of Bacteroidales sp. HOT 274, Desulfobulbus sp. HOT 041, Fretibacterium sp. HOT 360, and Fretibacterium sp. HOT 362 was found in subjects with GChP and GAgP than in PH subjects. Mean levels of P. gingivalis (r = 0.68), T. forsythia (r = 0.62), F. alocis (r = 0.51, P = 0.001), and Fretibacterium sp. HOT 360 (r = 0.41) were correlated with pocket depth (P < 0.001). In conclusion, Bacteroidales sp. HOT 274, Desulfobulbus sp. HOT 041, Fretibacterium sp. HOT 360, Fretibacterium sp. HOT 362, and TM7 sp. HOT 356 phylotypes, in addition to F. alocis, F. fastidiosum, and S. sputigena, seem to be associated with periodontitis, and their role in periodontal pathogenesis should be further investigated.

Amoxicillin Plus Metronidazole Therapy for Patients with Periodontitis and Type 2 Diabetes: A 2-year Randomized Controlled Trial.

The aim of this study was to assess the changes occurring in subgingival biofilm composition and in the periodontal clinical parameters of subjects with periodontitis and type 2 diabetes mellitus (DM) treated by means of scaling and root planing (SRP) only or combined with systemic metronidazole (MTZ) and amoxicillin (AMX). Fifty-eight subjects were randomly assigned to receive SRP only (n = 29) or with MTZ (400 mg/thrice a day [TID]) and AMX (500 mg/TID) (n = 29) for 14 d. Six subgingival plaque samples/subject were analyzed by checkerboard DNA-DNA hybridization for 40 bacterial species at baseline and 3 mo, 1 y, and 2 y posttherapy. At 2 y posttherapy, the antibiotic-treated group harbored lower mean proportions (5.5%) of red complex pathogens than the control group (12.1%) (P < 0.05). The proportions of the Actinomyces species remained stable in the antibiotic group but showed a statistically significant reduction in the control group from 1 to 2 y in subjects achieving a low risk clinical profile for future disease progression (i.e., ≤4 sites with probing depth [PD] ≥5 mm). The test group also had a lower mean number of sites with PD ≥5 mm (3.5 ± 3.4) and a higher percentage of subjects reaching the low risk clinical profile (76%) than the control group (14.7 ± 13.1 and 22%, respectively) (P < 0.05) at 2 y posttreatment. MTZ + AMX intake was the only significant predictor of subjects achieving the low risk at 2 y (odds ratio, 20.9; P = 0.0000). In conclusion, the results of this study showed that the adjunctive use of MTZ + AMX improves the microbiological and clinical outcomes of SRP in the treatment of subjects with generalized chronic periodontitis and type 2 DM up to 2 y (ClinicalTrials.gov NCT02135952).

Could cytokine levels in the peri-implant crevicular fluid be used to distinguish between healthy implants and implants with peri-implantitis? A systematic review.

BACKGROUND AND OBJECTIVE: Despite investigative efforts to identify the levels of different types of cytokines in the peri-implant crevicular fluid (PICF), the efficacy of these biomarkers in assisting the diagnosis of peri-implantitis is still undetermined. This systematic review aimed to answer the following question: "Could cytokine levels in the PICF be used to distinguish between healthy implants and implants with peri-implantitis?" MATERIAL AND METHODS: This review was conducted and reported in accordance with the PRISMA statement. The MEDLINE and EMBASE databases were searched from 1990 up to and including March 2015, using MeSH terms and other keywords. Additional publications were searched using a hand search of reference lists of relevant studies. Titles and abstracts were screened and papers that fulfilled eligibility criteria were assessed. RESULTS: Out of 1212 titles, 18 studies reporting the levels of nine different cytokines were included. Proinflammatory cytokines [interleukin (IL)-1ß, IL-6, IL-12, IL-17 and tumor necrosis factor-α) were the cytokines studied most commonly, followed by anti-inflammatory cytokines (IL-4 and IL-10), osteoclastogenesis-related cytokines (RANKL) and chemokines (IL-8). Nine studies reported statistically significantly higher levels of proinflammatory cytokines in the PICF of implants with peri-implantitis than in the PICF of healthy implants. Most studies did not find any significant differences in the PICF levels of anti-inflammatory cytokines and RANKL between healthy implants and implants with peri-implantitis. IL-8 was the only chemokine studied and its levels did not differ significantly between healthy and diseased implants. The studies differed greatly in the manner in which they reported the results (e.g. concentrations or total amounts) and in the exclusion of confounders, such as smoking. CONCLUSION: The results of this systematic review indicate moderate evidence in the literature to support that implants with peri-implantitis present higher levels of proinflammatory cytokines in the PICF than do healthy implants. Evidence regarding the PICF levels of anti-inflammatory cytokines, osteoclastogenesis-related cytokines and chemokines as possible predictors of peri-implantitis is too limited.

Evaluation of human and microbial DNA content in subgingival plaque samples collected by paper points or curette.

Host DNA may adversely affect metagenomic studies focusing on the prokaryotic microbiota. This study compared the levels of host DNA in subgingival plaque collected by paper points and curette, using quantitative PCR. Lower proportions of host DNA and higher proportions of bacterial DNA were recovered from samples collected with curettes.

Subgingival bacterial recolonization after scaling and root planing in smokers with chronic periodontitis.

BACKGROUND: The aim of this study was to compare subgingival bacterial recolonization patterns after scaling and root planing in current smokers and non-smokers. METHODS: 15 smokers and 15 non-smokers with chronic periodontitis received scaling and root planing in six visits lasting one hour each, over a period of 21 days. Clinical monitoring was performed at baseline and 180 days, and microbiological monitoring was performed at baseline, immediately after scaling and root planing (Day 0) and at 42, 63 and 180 days post-therapy. Subgingival plaque samples were analysed by checkerboard DNA-DNA hybridization. RESULTS: An improvement in clinical condition was observed for smokers and non-smokers; however, non-smokers showed a greater reduction in mean clinical attachment level in intermediate sites in comparison with smokers (p < 0.05). At Day 0, there was a significant reduction in the mean counts of the three pathogens from the red complex, Eubacterium nodatum and Parvimonas micra only in non-smokers (p < 0.05). There was a significant increase in the proportion of host-compatible species in non-smokers and smokers from baseline to 180 days post-therapy (p < 0.05). However, a significant decrease in the pathogenic species was observed only in non-smokers. CONCLUSIONS: Smokers were more susceptible to the re-establishment of a pathogenic subgingival biofilm than non-smokers.

Do subjects with aggressive and chronic periodontitis exhibit a different cytokine/chemokine profile in the gingival crevicular fluid? A systematic review.

BACKGROUND AND OBJECTIVE: Microbiological and immunological hypotheses have been raised to explain the differences in the clinical manifestations of aggressive periodontitis and chronic periodontitis. However, studies comparing the cytokine/chemokine profiles in gingival crevicular fluid between these two clinical conditions have so far not been compiled. This systematic review aimed to answer the following question: "Do subjects with aggressive periodontitis and chronic periodontitis have a different profile of cytokines/chemokines in the gingival crevicular fluid?" MATERIAL AND METHODS: An electronic database search of MEDLINE/PubMed and Embase was performed from 1990 up to and including August 2013, using MeSH terms and other keywords. Titles and abstracts were screened and the papers that satisfied eligibility criteria were assessed. RESULTS: Of 1954 titles, 17 studies reporting the levels of 21 different cytokines/chemokines were included. Most studies did not find any significant differences in the gingival crevicular fluid levels of cytokines/chemokines between aggressive periodontitis and chronic periodontitis. Some studies demonstrated that the levels of specific proinflammatory and anti-inflammatory cytokines/chemokines were higher (n = 5) and lower (n = 3), respectively, in aggressive periodontitis than in chronic periodontitis. The studies differed in the manner in which they reported the results (e.g. concentrations or total amounts). It was not clear in some studies whether the sample sites from both groups were matched for disease severity. Some studies did not take into account confounders, such as smoking. CONCLUSION: The current weight of evidence is not sufficient to prove that there are distinct gingival crevicular fluid cytokine/chemokine profiles for patients with aggressive periodontitis and chronic periodontitis.

Full-mouth scaling and root planing in type 2 diabetic subjects: one-year microbiological outcomes.

BACKGROUND: This study evaluated the microbiological effects of full-mouth (FM) and partial-mouth (PM) scaling and root planing (SRP) in type 2 diabetic subjects with chronic periodontitis (ChP), up to 12 months. METHODS: Thirty-four type 2 diabetic subjects with ChP received either FMSRP (n = 17), in two sessions within two consecutive days, or PMSRP (n = 17) in four sessions within 21 days. Six subgingival biofilm samples per subject were analysed by checkerboard DNA-DNA hybridization for 40 bacterial species at baseline, 3 and 12 months. RESULTS: Both therapies significantly reduced the levels of the red complex species up to 12 months (p < 0.05). The levels of three putative pathogens from the orange complex were significantly reduced in the FMSRP group, whereas a single orange complex species was significantly decreased in the PMSRP group (p < 0.05). Furthermore, the proportions of the host-compatible Actinomyces species were significantly increased in both groups at 3 and 12 months. No significant differences were observed between groups for the counts and proportions of the individual species and the proportions of microbial complexes at any time point (p > 0.05). CONCLUSIONS: There were no differences in the bacterial species evaluated after FMSRP and PMSRP in the treatment of type 2 diabetic subjects with ChP, up to 12 months.

Newly identified pathogens associated with periodontitis: a systematic review.

There is substantial evidence supporting the role of certain oral bacteria species in the onset and progression of periodontitis. Nevertheless, results of independent-culture diagnostic methods introduced about a decade ago have pointed to the existence of new periodontal pathogens. However, the data of these studies have not been evaluated together, which may generate some misunderstanding on the actual role of these microorganisms in the etiology of periodontitis. The aim of this systematic review was to determine the current weight of evidence for newly identified periodontal pathogens based on the results of "association" studies. This review was conducted and reported in accordance with the PRISMA statement. The MEDLINE, EMBASE, and Cochrane databases were searched up to September 2013 for studies (1) comparing microbial data of subgingival plaque samples collected from subjects with periodontitis and periodontal health and (2) evaluating at least 1 microorganism other than the already-known periodontal pathogens. From 1,450 papers identified, 41 studies were eligible. The data were extracted and registered in predefined piloted forms. The results suggested that there is moderate evidence in the literature to support the association of 17 species or phylotypes from the phyla Bacteroidetes, Candidatus Saccharibacteria, Firmicutes, Proteobacteria, Spirochaetes, and Synergistetes. The phylum Candidatus Saccharibacteria and the Archaea domain also seem to have an association with disease. These data point out the importance of previously unidentified species in the etiology of periodontitis and might guide future investigations on the actual role of these suspected new pathogens in the onset and progression of this infection.

Microbial diversity in persistent root canal infections investigated by checkerboard DNA-DNA hybridization.

INTRODUCTION: The aim of the present study was to investigate the composition of the root canal microbiota in endodontic failures in order to identify and quantify these microorganisms. METHODS: Microbiological samples were taken from 36 root canals with persistent endodontic infection. The presence, levels, and proportions of 79 bacterial species were determined by checkerboard DNA-DNA hybridization. The Pearson correlation coefficient was used to investigate the relations between bacterial counts and clinical conditions (P ≤ .05). RESULTS: Enterococcus faecium (36%), Streptococcus epidermidis (36%), Eubacterium saburreum (28%), Parvimonas micra (28%), Streptococcus sanguis (28%), Capnocytophaga sputigena (28%), Leptotrichia buccalis (28%), Enterococcus faecalis (28%), and Staphylococcus warneri (28%) were the most prevalent species; and there was a low prevalence of Treponema socranskii (3%), Fusobacterium periodonticum (3%), Capnocytophaga gingivalis (3%), and Spiroplasma ixodetis (3%). The highest mean levels were found for the following species: E. faecium, Dialister pneumosintes, Staphylococcus epidermidis and Helicobacter pylori. There was a statistically significant difference between the levels of gram-negative species and gram-positive species (13.5 × 10(5) vs 6.5 × 10(5), respectively). A positive correlation was found between the area of the periapical lesion and the levels of gram-negative and rod species (P < .05). CONCLUSIONS: The microbiota from teeth with persistent apical periodontitis presents a mixed and complex profile, hosting E. faecium and S. epidermidis as the most highly prevalent species. No correlation was found between any of the species tested and clinical findings; however, periapical lesions with the largest areas presented higher counts of gram-negative and rod species.

Reduction in prevalence of Archaea after periodontal therapy in subjects with generalized aggressive periodontitis.

BACKGROUND: There is evidence of a possible relationship between Archaea and periodontal disease; however, to date few studies have assessed the changes in prevalence of this domain after periodontal therapy. The aim of this randomized double-blind and placebo-controlled study was to assess if periodontal treatment with or without systemic antibiotic would change the prevalence of Archaea after periodontal therapy. METHODS: Thirty subjects were randomly assigned to receive scaling and root planing (SRP) alone or combined with metronidazole (MTZ) + amoxicillin (AMX) for 14 days. Clinical and microbiological examinations were performed at baseline and at six months post-SRP. Nine subgingival plaque samples per subject were analysed for the presence of Archaea. RESULTS: SRP alone or combined with MTZ + AMX significantly reduced the prevalence of subjects colonized by Archaea at six months post-therapy. However, no significant differences between treatment groups were observed (p > 0.05). Both therapies led to a statistically significant decrease in the mean percentage of sites colonized by Archaea (p < 0.05). A negative Spearman correlation was observed between the presence of Archaea and the mean clinical attachment gain at six months post-therapy (r(2) = -0.61; 95% CI -0.80- -0.31; p = 0.003). CONCLUSIONS: SRP alone or combined with MTZ + AMX provides a similar reduction in the prevalence of Archaea in the subgingival biofilm of subjects with generalized aggressive periodontitis.

The domain Archaea in human mucosal surfaces.

Archaea present distinct features from bacteria and eukaryotes, and thus constitute one of the branches of the phylogenetic tree of life. Members of this domain colonize distinct niches in the human body, arranged in complex communities, especially in the intestines and the oral cavity. The diversity of archaea within these niches is limited to a few phylotypes, constituted in particular by methane-producing archaeal organisms. Although they are possibly symbionts, methanogens may play a role in the establishment of mucosal diseases by favouring the growth of certain bacterial groups.

Levels of Selenomonas species in generalized aggressive periodontitis.

BACKGROUND AND OBJECTIVE: To compare the levels of Selenomonas sputigena and uncultivated/unrecognized Selenomonas species in subgingival biofilms from periodontally healthy subjects and from subjects with generalized aggressive periodontitis. MATERIAL AND METHODS: Fifteen periodontally healthy subjects and 15 subjects with generalized aggressive periodontitis were recruited and their clinical periodontal parameters were evaluated. Nine subgingival plaque samples were collected from each subject and all were individually analyzed for the levels of 10 bacterial taxa, including cultured and uncultivated/unrecognized microorganisms, using the RNA-oligonucleotide quantification technique. Between-group differences in the levels of the test taxa were determined using the Mann-Whitney U-test. RESULTS: Subjects with generalized aggressive periodontitis showed significantly higher mean counts of Porphyromonas gingivalis, S. sputigena and the Mitsuokella sp. Human Oral Taxon (HOT) 131 (previously described as Selenomonas sp. oral clone CS002), while higher mean counts of Actinomyces gerencseriae and Streptococcus sanguinis were found in periodontally healthy subjects (p < 0.01). Selenomonas sp. HOT 146 was only detected in the generalized aggressive periodontitis group. In the generalized aggressive periodontitis group, the levels of P. gingivalis and S. sputigena were higher in deep sites (probing depth ≥ 5 mm) than in shallow sites (probing depth ≤ 3 mm) (p < 0.01). Furthermore, in subjects with generalized aggressive periodontitis, sites with probing depth of ≤ 3 mm harbored higher levels of these two species than sites with the same probing depth in periodontally healthy subjects. There were positive correlations between probing depth and the levels of P. gingivalis (r = 0.77; p < 0.01), S. sputigena (r = 0.60; p < 0.01) and Selenomonas dianae (previously described as Selenomonas sp. oral clone EW076) (r = 0.42, p < 0.05). CONCLUSION: S. sputigena and Mitsuokella sp. HOT 131 may be associated with the pathogenesis of generalized aggressive periodontitis, and their role in the onset and progression of this infection should be investigated further.

Signaling transduction analysis in gingival epithelial cells after infection with Aggregatibacter actinomycetemcomitans.

Periodontal diseases result from the interaction of bacterial pathogens with the host's gingival tissue. Gingival epithelial cells are constantly challenged by microbial cells and respond by altering their transcription profiles, inducing the production of inflammatory mediators. Different transcription profiles are induced by oral bacteria and little is known about how the gingival epithelium responds after interaction with the periodontopathogenic organism Aggregatibacter actinomycetemcomitans. In the present study, we examined the transcription of genes involved in signaling transduction pathways in gingival epithelial cells exposed to viable A. actinomycetemcomitans. Immortalized gingival epithelial cells (OBA-9) were infected with A. actinomycetemcomitans JP2 for 24 h and the transcription profile of genes encoding human signal transduction pathways was determined. Functional analysis of inflammatory mediators positively transcribed was performed by ELISA in culture supernatant and in gingival tissues. Fifteen of 84 genes on the array were over-expressed (P < 0.01) after 24 h of infection with viable A. actinomycetemcomitans. Over-expressed genes included those implicated in tissue remodeling and bone resorption, such as CSF2, genes encoding components of the LDL pathway, nuclear factor-κB-dependent genes and other cytokines. The ELISA data confirmed that granulocyte-macrophage colony-stimulating factor/colony-stimulating factor 2, tumor necrosis factor-α and intercellular adhesion molecule-1 were highly expressed by infected gingival cells when compared with control non-infected cells, and presented higher concentrations in tissues from patients with aggressive and chronic periodontitis than in tissues from healthy controls. The induction in epithelial cells of factors such as the pro-inflammatory cytokine CSF2, which is involved in osteoclastogenesis, may help to explain the outcomes of A. actinomycetemcomitans infection.

Prevalence and microbiological diversity of Archaea in peri-implantitis subjects by 16S ribosomal RNA clonal analysis.

BACKGROUND AND OBJECTIVE: This study evaluated the prevalence and the molecular diversity of Archaea in the subgingival biofilm samples of subjects with peri-implantitis. MATERIAL AND METHODS: Fifty subjects were assigned into two groups: Control (n = 25), consisting of subjects with healthy implants; and Test (n = 25), consisting of subjects with peri-implantitis sites, as well as a healthy implant. In the Test group, subgingival biofilm samples were taken from the deepest sites of the diseased implant. In both groups, subgingival biofilm was collected from one site with a healthy implant and from one site with a periodontally healthy tooth. DNA was extracted and the 16S ribosomal RNA gene was amplified with universal primer pairs for Archaea. Amplified genes were cloned and sequenced, and the phylotypes were identified by comparison with known 16S ribosomal RNA sequences. RESULTS: In the Control group, Archaea were detected in two and three sites of the implant and the tooth, respectively. In the Test group, Archaea were detected in 12, 4 and 2 sites of diseased implants, healthy implants and teeth, respectively. Diseased implants presented a significantly higher prevalence of Archaea in comparison with healthy implants and natural teeth, irrespective of group. Over 90% of the clone libraries were formed by Methanobrevibacter oralis, which was detected in both groups. Methanobacterium congelense/curvum was detected in four subjects from the Test group and in two subjects from the Control group. CONCLUSION: Although M. oralis was the main species of Archaea associated with both healthy and diseased implant sites, the data indicated an increased prevalence of Archaea in peri-implantitis sites, and their role in pathogenesis should be further investigated.

Immune response to cytolethal distending toxin of Aggregatibacter actinomycetemcomitans in periodontitis patients.

BACKGROUND AND OBJECTIVE: Cytolethal distending toxin (CDT) is a genotoxin produced by Aggregatibacter actinomycetemcomitans. In spite of its association with pathogenesis, little is known about the humoral immune response against the CDT. This study aimed to test whether subgingival colonization and humoral response to A. actinomycetemcomitans would lead to a response against CDT. MATERIAL AND METHODS: Sera from periodontally healthy, localized and generalized aggressive periodontitis and chronic periodontitis subjects (n = 80) were assessed for immunoglobulin G titers to A. actinomycetemcomitans serotypes a/b/c and to each CDT subunit (CdtA, CdtB and CdtC) by ELISA. A. actinomycetemcomitans subgingival levels and neutralization of CDT activity were also analyzed. RESULTS: Sera from 75.0% localized and 81.8% generalized aggressive periodontitis patients reacted to A. actinomycetemcomitans. A response to serotype b was detected in localized (66.7%) and generalized aggressive periodontitis (54.5%). Reactivity to A. actinomycetemcomitans correlated with subgingival colonization (R = 0.75, p < 0.05). There was no correlation between A. actinomycetemcomitans colonization or response to serotypes and the immunoglobulin G response to CDT subunits. Titers of immunoglobulin G to CdtA and CdtB did not differ among groups; however, sera of all generalized aggressive periodontitis patients reacted to CdtC. Neutralization of CDT was not correlated with levels of antibodies to CDT subunits. CONCLUSION: Response to CdtA and CdtB did not correlate with the periodontal status of the subject in the context of an A. actinomycetemcomitans infection. However, a response to CdtC was found in sera of generalized but not of localized aggressive periodontitis subjects. Differences in response to CdtC between generalized and localized aggressive periodontitis subjects indicate that CDT could be expressed differently by the infecting strains. Alternatively, the antibody response to CdtC could require the colonization of multiple sites.

TNF-alpha and IL-4 levels in generalized aggressive periodontitis subjects.

OBJECTIVES: The aim of this study was to evaluate tumor necrosis factor (TNF)-alpha and interleukin (IL)-4 levels in healthy sites and sites exhibiting signs of moderate and advanced generalized aggressive periodontitis (GAgP) in the same subject. METHODS: The following sites were selected for crevicular fluid sampling in the same AgP subject (n = 14): Healthy sites (HS): no marginal bleeding or bleeding on probing (BOP) and probing depth (PD) or= 7 mm. One site from periodontally healthy subjects (n = 13) was sampled for use as a control. TNF-alpha and IL-4 levels were measured using ELISA. RESULTS: The total amount of TNF-alpha was lower for control sites, while there were no differences among healthy and diseased sites from GAgP subjects (P < 0.05). The concentration of TNF-alpha was higher in HS, in relation to the other sites (P < 0.05). There were no significant differences among the groups regarding total amounts of IL-4 (P > 0.05), while IL-4 concentration was significantly higher in control sites, when compared with sites from GAgP subjects (P < 0.05). CONCLUSION: In conclusion, high levels of TNF-alpha and low levels of IL-4 were observed in both healthy and diseased sites within the same generalized AgP individuals.

Microbiological evaluation of primary endodontic infections in teeth with and without sinus tract.

AIM: To examine the microbiological status of primary endodontic infections in teeth with and without a sinus tract. METHODOLOGY: Samples were collected by means of a size 15 H-type file and two sterile paper points from 30 cases of primary endodontic infections with (n = 15) or without (n = 15) a sinus tract. The presence of 40 bacterial species was determined by the checkerboard DNA-DNA hybridization method. RESULTS: The species found at the highest levels and prevalence were Fusobacterium nucleatum sp. vincentii, Porphyromonas gingivalis, Veillonella parvula, Enterococcus faecalis, Campylobacter gracilis and Neisseria mucosa. Total bacterial counts were similar between teeth with (44 x 10(5)) and without (50 x 10(5)) a sinus tract (t-test: P > 0.05). E. faecalis, Streptococcus anginosus, Capnocytophaga sputigena and Capnocytophaga gingivalis had significantly higher counts in the absence of sinus tract (Mann-Whitney test, P < 0.05). Higher levels of P. gingivalis and Fusobacterium nucleatum sp. nucleatum were observed in cases with a sinus tract. Leptotrichia buccalis (OR = 1.83; CI 95%) and Porphyromonas endodontalis (OR = 2.15; CI 95%) were associated with an increased chance of subjects having a sinus tract. CONCLUSIONS: Primary endodontic infections were associated with a large variety of bacterial species. Specific differences between the composition of the microbiota of primary root canal infections were observed in cases with or without a sinus tract.

Histological comparison between implants retrieved from patients with and without osteoporosis.

The aim of this restrospective histologic study was to evaluate the bone-to-implant contact of loaded implants retrieved from patients with and without osteoporosis. The evaluated material consisted of 22 threaded, cylindrical, loaded dental implants retrieved from 21 patients: 7 from 7 women with postmenopausal osteoporosis (osteoporosis group) and the remaining 15 from 14 patients without history of osteoporosis or other metabolic diseases (control group). Histologic analysis revealed bone tissue in the threads of the retrieved implants, with variations in the percentage of bone-to-implant contact for the implants retrieved from both groups. The pristine bone was mostly mature bone and/or lamellar and compact, and numerous osteocytes were observed in the lacunae, although areas of woven bone could be distinguished. In some specimens, there were areas of newly formed bone exhibiting different degrees of maturation and remodeling. The mean bone-to-implant contact was 46.00+/-11.46% and 47.84+/-14.03% for the osteoporosis group and control group, respectively. The results of this histomorphometric study suggest that osteoporosis may not be a contra-indication for implant placement, at least after osseointegration has been established.