Colonization dynamics of subgingival microbiota in recently installed dental implants compared to healthy teeth in the same individual: a 6-month prospective observational study.

OBJECTIVES: To evaluate the colonization dynamics of subgingival microbiota established over six months around newly installed dental implants in periodontally healthy individuals, compared with their corresponding teeth. METHODOLOGY: Seventeen healthy individuals assigned to receive single dental implants participated in the study. Subgingival biofilm was sampled from all implant sites and contralateral/ antagonist teeth on days 7, 30, 90, and 180 after implant installation. Microbiological analysis was performed using the Checkerboard DNA-DNA hybridization technique for detection of classical oral taxa and non-oral microorganisms. Significant differences were estimated by Mann-Whitney and Friedman tests, while associations between implants/teeth and target species levels were assessed by linear regression analysis (LRA). Significance level was set at 5%. RESULTS: Levels of some species were significantly higher in teeth compared to implants, respectively, at day 7 ( V.parvula , 6 × 10 5 vs 3 × 105 ; Milleri streptococci , 2 × 10 6 vs 6 × 10 5 ; Capnocytophaga spp., 2 × 10 6 vs 9 × 10 5 ; E.corrodens , 2 × 10 6 vs 5 × 10 5 ; N. mucosa , 2 × 10 6 vs 5 × 10 5 ; S.noxia , 2 × 10 6 vs 3 × 10 5 ; T.socranskii , 2 × 10 6 vs 5 × 10 5 ; H.alvei , 4 × 10 5 vs 2 × 10 5 ; and Neisseria spp., 6 × 10 5 vs 4 × 10 4 ), day 30 ( V.parvula , 5 × 10 5 vs 10 5 ; Capnocytophaga spp., 1.3 × 10 6 vs 6.8 × 10 4 ; F.periodonticum , 2 × 10 6 vs 10 6 ; S.noxia , 6 × 10 5 vs 2 × 10 5 ; H.alvei , 8 × 10 5 vs 9 × 10 4 ; and Neisseria spp., 2 × 10 5 vs 10 6 ), day 120 ( V.parvula , 8 × 10 5 vs 3 × 10 5 ; S.noxia , 2 × 10 6 vs 0; and T.socranskii , 3 × 10 5 vs 8 × 10 4 ), and day 180 ( S.enterica subsp. enterica serovar Typhi, 8 × 10 6 vs 2 × 10 6 ) (p<0.05). Implants showed significant increases over time in the levels of F.nucleatum , Gemella spp., H.pylori , P.micra , S.aureus , S.liquefaciens , and T.forsythia (p<0.05). LRA found that dental implants were negatively correlated with high levels of S. noxia and V. parvula (ß=-0.5 to -0.3; p<0.05). CONCLUSIONS: Early submucosal microbiota is diverse and only a few species differ between teeth and implants in the same individual. Only 7 days after implant installation, a rich microbiota can be found in the peri-implant site. After six months of evaluation, teeth and implants show similar prevalence and levels of the target species, including known and new periodontopathic species.

Antimicrobial resistance and virulence of subgingival staphylococci isolated from periodontal health and diseases.

The dysbiotic biofilm of periodontitis may function as a reservoir for opportunistic human pathogens of clinical relevance. This study explored the virulence and antimicrobial susceptibility of staphylococci isolated from the subgingival biofilm of individuals with different periodontal conditions. Subgingival biofilm was obtained from 142 individuals with periodontal health, 101 with gingivitis and 302 with periodontitis, and cultivated on selective media. Isolated strains were identified by mass spectrometry. Antimicrobial susceptibility was determined by disk diffusion. The mecA and virulence genes were surveyed by PCR. Differences among groups regarding species, virulence and antimicrobial resistance were examined by Chi-square, Kruskal-Wallis or Mann-Whitney tests. The overall prevalence of subgingival staphylococci was 46%, especially in severe periodontitis (> 60%; p < 0.01). S. epidermidis (59%) and S. aureus (22%) were the predominant species across groups. S. condimenti, S. hominis, S. simulans and S. xylosus were identified only in periodontitis. High rates of resistance/reduced sensitivity were found for penicillin (60%), amoxicillin (55%) and azithromycin (37%), but multidrug resistance was observed in 12% of the isolates. Over 70% of the mecA + strains in periodontitis were isolated from severe disease. Higher detection rates of fnB + isolates were observed in periodontitis compared to health and gingivitis, whereas luxF/luxS-pvl + strains were associated with sites with deep pockets and attachment loss (p < 0.05). Penicillin-resistant staphylococci is highly prevalent in the subgingival biofilm regardless of the periodontal status. Strains carrying virulence genes related to tissue adhesion/invasion, inflammation and cytotoxicity support the pathogenic potential of these opportunists in the periodontal microenvironment.

Antimicrobial activity of violacein against oral bacteria associated with halitosis: an in vitro study

Introduction: violacein is a natural purple pigment produced by environmental bacteria that presents antimicrobial activity, particularly against Gram-positive bacteria. Intraoral halitosis (IOH) is a condition defined by the unpleasant odor emanating from the mouth, whose main source are volatile sulfur compounds, produced by Gram-negative oral bacteria on the tongue coating. In IOH treatment, antimicrobials have been indicated as chemical adjuncts, including natural products. Objective: thus, this study tested the antimicrobial activity of a violacein extract on key IOH-related bacteria (Porphyromonas gingivalis, Porphyromonas endodontalis, Fusobacterium nucleatum, Prevotella intermedia, Solobacterium moorei). Materials and Methods: bacteria were cultured in fastidious anaerobe blood agar in anaerobiosis, and 109 cells/ml suspensions were plated. Crude extract of violacein obtained from Chromobacterium violaceum was diluted in a 25% ethanol aqueous solution to 8, 4, 2, 1, 0.5 and 0.25 mg/ml. Using the disk agar diffusion method, 10 µl aliquots of each dilution were deposited on the seeded plates. Chlorohexidine (0.1%) and 25% ethanol solution were used as controls. Plates were incubated in anaerobiosis at 37°C for 72h, and the inhibition halos were recorded. Results: although chlorhexidine showed higher inhibition halos than the violacein extract, most species were inhibited at 4 and 8 mg/ml concentrations (p<0.05). P. gingivalis followed by F. nucleatum were the most affected species in relation to the other bacteria, although statistical significance was only reached for P. gingivalis (p<0.05). Conclusion: crude violacein extract from C. violaceum demonstrated antimicrobial activity against IOH-associated oral bacteria, being a potential antimicrobial to be studied as an adjunct in the control of IOH.

Introdução: a violaceína é um pigmento roxo natural produzido por bactérias ambientais que apresenta ação antimicrobiana, particularmente contra bactérias Gram-positivas. A halitose intraoral (HIO) é uma condição definida pelo odor desagradável que emana da boca, cuja principal fonte são os compostos sulfurados voláteis produzidos por bactérias Gram-negativas da saburra lingual. No tratamento da HIO, antimicrobianos têm sido indicados como adjuvantes, incluindo produtos naturais. Objetivo: assim, este estudo avaliou o potencial antimicrobiano de um extrato de violaceína em patógenos-chave da HIO (Porphyromonas gingivalis, Porphyromonas endodontalis, Fusobacterium nucleatum, Prevotella intermedia, Solobacterium moorei). Materiais e Métodos: bactérias foram cultivadas em meio ágar sangue para fastidiosos, em anaerobiose, e suspensões de 109 células/ml foram semeadas. O extrato bruto de violaceína obtido de Chromobacterium violaceum foi diluído em solução aquosa com 25% de etanol nas concentrações de 8, 4, 2, 1, 0,5 e 0,25 mg/ml. Através do método de disco difusão, 10 µl de cada diluição foram depositados nas placas semeadas. A clorexidina (0,1%) e a solução etanólica a 25% foram usadas como controles. As placas foram incubadas em anaerobiose a 37°C por 72h, e os halos de inibição foram registrados. Resultados: embora a clorexidina tenha apresentado os maiores halos de inibição do do que o extrato, a maioria das espécies foi inibida nas concentrações de 4 e 8 mg/ml (p<0,05). P. gingivalis e F. nucleatum foram as espécies mais afetadas em relação às outras bactérias, porém só foi observada significância estatística para P. gingivalis (p<0,05). Conclusão: o extrato bruto de violaceína de C. violaceum demonstrou atividade antimicrobiana contra bactérias orais associadas a HIO, sendo um potencial antimicrobiano a ser estudado como adjuvante no controle da HIO.

Periodontal disease severity is associated to pathogenic consortia comprising putative and candidate periodontal pathogens.

BACKGROUND: Based on a holistic concept of polymicrobial etiology, we have hypothesized that putative and candidate periodontal pathogens are more frequently detected in consortia than alone in advanced forms of periodontal diseases (PD). OBJECTIVE: To correlate specific consortia of periodontal pathogens with clinical periodontal status and severity of periodontitis. METHODOLOGY: Subgingival biofilm was obtained from individuals with periodontal health (113, PH), gingivitis (91, G), and periodontitis (209, P). Genomic DNA was purified and the species Aggregatibacter actinomycetemcomitans (Aa), Aa JP2-like strain, Porphyromonas gingivalis (Pg), Dialister pneumosintes (Dp), and Filifactor alocis (Fa) were detected by PCR. Configural frequency and logistic regression analyses were performed to correlate microbial consortia and PD. RESULTS: Aa + Pg in the presence of Dp (phi=0.240; χ2=11.9, p<0.01), as well as Aa JP2 + Dp + Fa (phi=0.186, χ2=4.6, p<0.05) were significantly more associated in advanced stages of P. The consortium Aa + Fa + Dp was strongly associated with deep pocketing and inflammation (p<0.001). The best predictors of disease severity (80% accuracy) included older age (OR 1.11 [95% CI 1.07 - 1.15], p<0.001), Black/African-American ancestry (OR 1.89 [95% CI 1.19 - 2.99], p=0.007), and high frequency of Aa + Pg + Dp (OR 3.04 [95% CI 1.49 - 6.22], p=0.002). CONCLUSION: Specific microbial consortia of putative and novel periodontal pathogens, associated with demographic parameters, correlate with severe periodontitis, supporting the multifactorial nature of PD.

Colonization dynamics of subgingival microbiota in recently installed dental implants compared to healthy teeth in the same individual: a 6-month prospective observational study

Abstract Objectives To evaluate the colonization dynamics of subgingival microbiota established over six months around newly installed dental implants in periodontally healthy individuals, compared with their corresponding teeth. Methodology Seventeen healthy individuals assigned to receive single dental implants participated in the study. Subgingival biofilm was sampled from all implant sites and contralateral/ antagonist teeth on days 7, 30, 90, and 180 after implant installation. Microbiological analysis was performed using the Checkerboard DNA-DNA hybridization technique for detection of classical oral taxa and non-oral microorganisms. Significant differences were estimated by Mann-Whitney and Friedman tests, while associations between implants/teeth and target species levels were assessed by linear regression analysis (LRA). Significance level was set at 5%. Results Levels of some species were significantly higher in teeth compared to implants, respectively, at day 7 ( V.parvula , 6 × 10 5 vs 3 × 105 ; Milleri streptococci , 2 × 10 6 vs 6 × 10 5 ; Capnocytophaga spp., 2 × 10 6 vs 9 × 10 5 ; E.corrodens , 2 × 10 6 vs 5 × 10 5 ; N. mucosa , 2 × 10 6 vs 5 × 10 5 ; S.noxia , 2 × 10 6 vs 3 × 10 5 ; T.socranskii , 2 × 10 6 vs 5 × 10 5 ; H.alvei , 4 × 10 5 vs 2 × 10 5 ; and Neisseria spp., 6 × 10 5 vs 4 × 10 4 ), day 30 ( V.parvula , 5 × 10 5 vs 10 5 ; Capnocytophaga spp., 1.3 × 10 6 vs 6.8 × 10 4 ; F.periodonticum , 2 × 10 6 vs 10 6 ; S.noxia , 6 × 10 5 vs 2 × 10 5 ; H.alvei , 8 × 10 5 vs 9 × 10 4 ; and Neisseria spp., 2 × 10 5 vs 10 6 ), day 120 ( V.parvula , 8 × 10 5 vs 3 × 10 5 ; S.noxia , 2 × 10 6 vs 0; and T.socranskii , 3 × 10 5 vs 8 × 10 4 ), and day 180 ( S.enterica subsp. enterica serovar Typhi, 8 × 10 6 vs 2 × 10 6 ) (p<0.05). Implants showed significant increases over time in the levels of F.nucleatum , Gemella spp., H.pylori , P.micra , S.aureus , S.liquefaciens , and T.forsythia (p<0.05). LRA found that dental implants were negatively correlated with high levels of S. noxia and V. parvula (β=-0.5 to -0.3; p<0.05). Conclusions Early submucosal microbiota is diverse and only a few species differ between teeth and implants in the same individual. Only 7 days after implant installation, a rich microbiota can be found in the peri-implant site. After six months of evaluation, teeth and implants show similar prevalence and levels of the target species, including known and new periodontopathic species.

Periodontal disease severity is associated to pathogenic consortia comprising putative and candidate periodontal pathogens

Abstract Based on a holistic concept of polymicrobial etiology, we have hypothesized that putative and candidate periodontal pathogens are more frequently detected in consortia than alone in advanced forms of periodontal diseases (PD). Objective To correlate specific consortia of periodontal pathogens with clinical periodontal status and severity of periodontitis. Methodology Subgingival biofilm was obtained from individuals with periodontal health (113, PH), gingivitis (91, G), and periodontitis (209, P). Genomic DNA was purified and the species Aggregatibacter actinomycetemcomitans (Aa), Aa JP2-like strain, Porphyromonas gingivalis (Pg), Dialister pneumosintes (Dp), and Filifactor alocis (Fa) were detected by PCR. Configural frequency and logistic regression analyses were performed to correlate microbial consortia and PD. Results Aa + Pg in the presence of Dp (phi=0.240; χ2=11.9, p<0.01), as well as Aa JP2 + Dp + Fa (phi=0.186, χ2=4.6, p<0.05) were significantly more associated in advanced stages of P. The consortium Aa + Fa + Dp was strongly associated with deep pocketing and inflammation (p<0.001). The best predictors of disease severity (80% accuracy) included older age (OR 1.11 [95% CI 1.07 - 1.15], p<0.001), Black/African-American ancestry (OR 1.89 [95% CI 1.19 - 2.99], p=0.007), and high frequency of Aa + Pg + Dp (OR 3.04 [95% CI 1.49 - 6.22], p=0.002). Conclusion Specific microbial consortia of putative and novel periodontal pathogens, associated with demographic parameters, correlate with severe periodontitis, supporting the multifactorial nature of PD.

Oral-gut bacterial profiles discriminate between periodontal health and diseases.

OBJECTIVE: This investigation explored oral-gut microbial signatures with potential to distinguish among periodontal conditions. BACKGROUND DATA: The interplay between the oral and gut microbiomes may be a critical pathway linking periodontal diseases and systemic inflammatory disorders. The mechanisms by which oral microorganisms translocate to the gut and cause microbial dysbiosis, favoring an inflammatory state, are still unknown. As a first approach, characterization of oral-gut microbial profiles associated with periodontal health and diseases can provide insights on such mechanisms of etiology and pathogenesis. METHODS: Fecal and saliva samples from individuals with periodontal health (PH, 8), gingivitis (GG, 17), and periodontitis (PD, 24) were analyzed for their microbial composition by 16S rRNA gene sequencing. Microbial taxa were compared and correlated to periodontal parameters. Multivariate discriminant analysis (MDA) was carried out to identify profiles related to health and disease. RESULTS: Few significant differences in oral-gut taxa were detected among clinical groups, although increase in fecal Fusobacterium nucleatum ss vincentii and salivary Aggregatibacter actinomycetemcomitans, Parvimonas micra, and Fretibacterium sp. HMT358 were strongly correlated with deep pockets and inflammation (p < .01). Over 50% of the fecal microbiota comprised microorganisms shared between oral and gut sites, whereas oral taxa were detected in approximately 9%, particularly enriched in GG fecal samples (p = .04). Trends for lower fecal richness and higher salivary diversity in PD compared to PH were observed. MDA was able to classify correctly 82% of the patients into the clinical groups. Main classifiers of periodontitis were high BMI, older age, and enrichment of oral-fecal Leptotrichia sp. HMT4, Peptostreptococcus stomatis, Dialister invisus, and a novel Lautropia sp. HMTC89-like organism. CONCLUSION: Within the limitations of an exploratory investigation, specific profiles of oral-gut taxa, including known and potential novel organisms, combined with social-demographic features were able to discriminate individuals with periodontal diseases in this study population.

Impact of systemic probiotics as adjuncts to subgingival instrumentation on the oral-gut microbiota associated with periodontitis: A randomized controlled clinical trial.

BACKGROUND: The oral-gut axis may be a route linking periodontal and systemic diseases. Probiotics could be an alternative for the treatment of microbial dysbiotic conditions, including periodontitis. This randomized placebo-controlled clinical trial evaluated the short-term efficacy of systemic probiotics adjunctive to subgingival instrumentation (SI) in promoting a better restoration of the oral-gut microbiotas and greater periodontal clinical outcome. METHODS: Systemically healthy adults with untreated periodontitis were recruited from a Dental School setting and allocated to receive SI plus placebo (n = 24) or probiotics (n = 24), one capsule/day for 30 days. Subgingival biofilm and stool were obtained at baseline and 2-months post-therapy for microbiological analyses by checkerboard and 16S rRNA gene sequencing. Differences in all parameters between placebo (n = 23) and probiotics (n = 19) groups were assessed by non-parametric tests. RESULTS: Most subgingival species and α-diversity decreased after therapies (P <0.05), whereas gut composition/diversity were slightly or not affected by treatments. In parallel, significant clinical improvement (P <0.05) was similar between groups, although a trend for a higher proportion of poor responders in the placebo (60.8%) than the probiotic group (31.5%) was observed (P = 0.07). Strong correlations between oral and fecal species were found (P <0.01), and distinct species related to poor response for different therapies (P <0.05). Patients were classified into five periodontitis oral-gut microbial clusters, which correlated differently with attachment loss after therapies (P <0.05). CONCLUSION: Systemic probiotics combined with SI did not provide short-term additional clinical or microbiological benefits in the treatment of periodontitis; however, response to therapies seemed to correlate with distinct oral-gut microbial profiles.

Prevalence and antimicrobial susceptibility of Gram-negative bacilli in subgingival biofilm associated with periodontal diseases.

BACKGROUND: This cross-sectional study aimed to determine the prevalence and antimicrobial susceptibility of Gram-negative bacilli (GNB) isolated from subgingival biofilm of individuals with different periodontal conditions. METHODS: Subgingival biofilm was obtained from 362 individuals with periodontal health (PH) (n = 83), gingivitis (n = 74), and periodontitis (n = 205), cultivated in broth and selective media. Isolated strains were identified by mass spectrometry. Antimicrobial susceptibility was determined by the Clinical and Laboratory Standards Institute disk diffusion guidelines. Production of extended-spectrum beta-lactamase (ESBL) and carbapenemases were evaluated by double disk synergy test and spectrophotometric detection of imipenem hydrolysis, respectively. ESBL and carbapenemase encoding genes were surveyed by Polymerase chain reaction (PCR). Differences among groups were examined by Chi-square, Kruskal-Wallis or Mann-Whitney tests. RESULTS: GNB were isolated from 36.2% of all subgingival biofilm samples, with a significantly greater prevalence and species diversity (P < 0.001) in patients with periodontitis (45.9%) compared with individuals with PH (24.1%) and gingivitis (22.9%). Pseudomonas aeruginosa (27.5%), Enterobacter cloacae (16.8%), and Enterobacter asburiae (10.7%) were the most predominant species. Resistance/reduced sensitivity to at least 1 antimicrobial was detected in 60% of the strains, but only 4.6% were multidrug resistant. Serratia marcescens, E. cloacae, and Enterobacter kobei presented high rates of intrinsic resistance (>40%) to amoxicillin-clavulanate and first/second-generations of cephalosporins. One strain of Klebsiella pneumoniae isolated from periodontitis was resistant to imipenem, but no ESBL encoding genes or ESBL phenotype was detected. CONCLUSION: High prevalence and diversity of GNB, with low susceptibility to ß-lactams are observed in the subgingival microbiota associated with periodontitis.

Development, characterization and photobiological activity of nanoemulsion containing zinc phthalocyanine for oral infections treatment.

Nanotechnology, when applied to PDT's, allows the encapsulation of ZnPc in nanocarriers, producing thus nanoemulsions that permit the use of ZnPc as photosensitizers. The Enterococcus faecalis and methicillin-resistant Staphylococcus aureus (MRSA) are microorganisms present in biofilms which can cause resistant endodontic infections. The objective of this work is the development and characterization of clove essential oil nanoemulsions containing ZnPc. The formulations were developed according to factorial experimental planning and characterized by the determination of the mean drop size, Polydispersity Index (PdI), content, organoleptic characteristics, stability, morphology, cytotoxicity in the dark and evaluation of the photobiological activity. The experimental planning was able to indicate the maximum amount of ZnPc that could be encapsulated in the nanoemulsion while maintaining droplet size <50 nm and PdI < 0.2. The surface plots for the response variables indicated a robust region for the combination of Pluronic® F-127 and clove oil factors. The result of this study was the choice of the nanoemulsion containing ZnPc solution at 5%, clove oil at 5%, Pluronic® F-127 at 10% and will be codified as ZnPc-NE. The nanoemulsion presented a mean diameter of 30.52 nm, PDI < 0.2 and a concentration of 17.5 µg/mL, as well as stability at room temperature for 180 days. TEM showed that the drops are spherical with nanometric size, which corroborates the results of dynamic light scattering. Concerning the photobiological activity, the ZnPc-NE exhibited MIC 1.09 µg/mL for Enterococcus faecalis and 0.065 µg/mL for MRSA (Methicillin-resistant Staphylococcus aureus). ZnPc-NE showed higher photobiological activity than free ZnPc. Besides, cytotoxicity studies showed that blank-NE (nanoemulsions without PS) showed good antimicrobial activity. Thus, clove oil nanoemulsion is an excellent nanocarrier to promote the photobiological activity of the ZnPc against pathogenic microorganisms.

Proteomic analysis of whole saliva in chronic periodontitis.

Periodontitis is a chronic inflammatory disease resulting from a dysbiosis of the dental biofilm and a dysregulated host response in susceptible individuals. It is characterized by periodontal attachment destruction, bone resorption and eventual tooth loss. Salivary biomarkers have been sought to predict and prevent periodontitis. This comparative study analyzed the salivary proteome of individuals with chronic periodontitis (CP) and periodontal health (PH) and correlated specific proteins with clinical parameters of disease by using mass spectrometry. Stimulated whole saliva was obtained 10 PH and 30 CP patients and pooled into 5 healthy control samples and 15 CP samples. After precipitation with TCA, samples were digested enzymatically with trypsin and analyzed by a LTQ Orbitrap Velos equipped with a nanoelectrospray ion source. A wide range of salivary proteins of various functions was significantly reduced in CP individuals, whereas salivary acidic proline-rich phosphoprotein, submaxillary gland androgen-regulated protein, histatin-1, fatty acid binding protein, thioredoxin and cystatin-SA were predominant in diseased patients and correlated significantly with signs of periodontal attachment loss and inflammation. In conclusion, few specific salivary proteins were associated with CP. These findings may contribute to the identification of disease indicators or signatures for the improvement of periodontal diagnosis. SIGNIFICANCE: Periodontitis is a chronic inflammatory disease that results in periodontal attachment destruction, bone resorption and eventual tooth loss. Salivary biomarkers have been sought to predict periodontitis. The analysis of the salivary proteome of individuals with chronic periodontitis indicated that several proteins of various functions were significantly reduced in these individuals, except for salivary acidic proline-rich phosphoprotein, submaxillary gland androgen-regulated protein, histatin, fatty acid binding protein, thioredoxin and cystatin. Differences in salivary proteome profiles between periodontal health and periodontitis may contribute to the identification of disease indicators and to the improvement of periodontal diagnosis and treatment.

Defining the gut microbiota in individuals with periodontal diseases: an exploratory study.

Background: This exploratory study aimed to characterize the gut microbiome of individuals with different periodontal conditions, and correlate it with periodontal inflammation and tissue destruction. Methods: Stool samples were obtained from individuals presenting periodontal health (PH = 7), gingivitis (G = 14) and chronic periodontitis (CP = 23). The intestinal microbiome composition was determined by Illumina MiSeq sequencing. Results: A lower alpha-diversity in the gut microbiome of individuals with CP was observed, although no significant difference among groups was found (p > 0.01). Firmicutes, Proteobacteria, Verrucomicrobia and Euryarchaeota were increased, whereas Bacteroidetes were decreased in abundance in patients with periodontitis compared to PH. Prevotella (genus), Comamonadaceae (family) and Lactobacillales (order) were detected in higher numbers in G, while Bacteroidales (order) was predominant in PH (p < 0.01). Significant correlations (rho = 0.337-0.468, p < 0.01) were found between OTUs representative of periodontal pathogens and attachment loss. Mogibacteriaceae, Ruminococcaceae and Prevotella were able to discriminate individuals with periodontal diseases from PH (overall accuracy = 84%). Oral taxa were detected in high numbers in all stool samples. Conclusions: Individuals with periodontal diseases present a less diverse gut microbiome consistent with other systemic inflammatory diseases. High numbers of oral taxa related to periodontal destruction and inflammation were detected in the gut microbiome of individuals regardless of periodontal status.

Clinical and microbiological effectiveness of photodynamic therapy on primary endodontic infections: a 6-month randomized clinical trial.

INTRODUCTION: This short-term randomized controlled trial evaluated the effectiveness of photodynamic therapy (PDT) on clinical success (periapical healing) and on the microbiota of primary endodontic infections. METHODS: Thirty-two patients presenting mandibular molars with apical periodontitis (one tooth/patient) were selected and randomly allocated into two therapeutic groups: control (chemo-mechanical debridement [CMD]; n = 16) and PDT (CMD + PDT; n = 16). All teeth in both groups had intracanal medication with calcium hydroxide for 7 days before final obturation. Follow-up radiographs were made at 3 and 6 months. Periapical healing was evaluated by the periapical index (PAI). Samples were obtained at baseline, after CMD with or without PDT, and just before root filling to determine the frequency and levels of 37 taxa by checkerboard. RESULTS: Significant decreases in PAI scores were observed in both groups over time, although at 6 months, the PDT group presented a significantly better healing score than the control (p < 0.05). At baseline, the most prevalent species in all samples were Candida albicans (46.9%), Dialister pneumosintes (31.2%), Prevotella nigrescens (28.2%), Prevotella tannerae (28.1%), and Peptostreptococcus anaerobius (25%). Most species reduced over time in both groups, and no significant differences in frequency and levels of the tested species were observed between groups in any time point evaluated. C. albicans and D. pneumosintes were still detected in high frequency in both groups at 3 months post-therapy. CONCLUSIONS: Conventional endodontic therapy with or without PDT is effective in reducing microbial load, resulting in periapical healing. Nevertheless, adjunctive PDT provides better periapical healing at 6-month follow-up. CLINICAL RELEVANCE: Teeth with apical periodontitis treated with PDT adjunct to conventional treatment would demonstrate superior healing and reduction of microorganisms.

The effect of supragingival biofilm re-development on the subgingival microbiota in chronic periodontitis.

OBJECTIVE: In this study, we hypothesized that in the absence of oral hygiene, re-growth of the climax microbial communities of supra and subgingival biofilm happens in a faster and more intense fashion in individuals with chronic periodontitis (CP) compared to periodontally healthy controls (PH). DESIGN: Thirty patients (PH=15 and CP=15) received professional supragingival prophylaxis, and were asked to refrain from oral hygiene for 7days. Supra and subgingival biofilm samples and GCF were collected from randomly selected quadrants at baseline (before prophylaxis), immediately after prophylaxis, 2h, 6h, 24h, and 7days after prophylaxis. The composition of the biofilm was determined by the checkerboard method. RESULTS: All subjects developed gingivitis at the end of 7days without oral hygiene. GCF mean volumes were significantly higher in CP than PH patients at baseline, but they started decreasing 2h after prophylaxis, returning to baseline levels after 24h in both groups. Significant increases in mean counts for most of the species evaluated were observed in both groups and biofilms over time (p<0.05). Few hours after prophylaxis, a more marked reduction in microbial counts happened in the supragingival biofilm of the CP group, and re-development of biofilm started later than in the PH group. At 7days, no differences were seen between groups. Significant differences in kinetics of re-colonization between groups were observed only in the subgingival biofilm for T. denticola and F. nucleatum ss vicentii (increased in the CP), and N. mucosa (increased in the PH group; p<0.05). CONCLUSIONS: Biofilm re-development was very similar between CP and PH individuals, although microbial re-growth occurred few hours earlier in PH than PC. Only 3 species in the subgingival biofilm differed in re-colonization between groups. Thus, we reject the hypothesis that re-colonization of biofilm in CP patients is more intense and faster than in individuals with PH.

Lack of adjunctive effect of 0.1% sodium hypochlorite mouthwash combined to full-mouth ultrasonic debridement on supragingival plaque, gingival inflammation, and subgingival microbiota: A randomized placebo-controlled 6-month trial.

To test the adjunctive effect of 0.1% sodium hypochlorite (NaOCl) mouthwash combined to full-mouth ultrasonic debridement (FMUD) on reducing supragingival plaque, gingival inflammation, and microbial pathogens. In this 6-month double-blinded randomized clinical trial, individuals with gingivitis were assigned to test (n = 16) or placebo group (n = 16) and received FMUD followed by rinsing with 0.1% NaOCl (test) or distilled water (placebo), respectively, twice a day for 1 month. Full-mouth periodontal examination was performed at baseline, 1, 3, and 6 months posttherapy, and subgingival plaque samples were obtained at the same time points and analysed for their composition by checkerboard. Differences between groups over time were examined by Student t test, Mann-Whitney, generalized linear model, and Friedman and chi-square tests. Both therapeutic protocols resulted in significant clinical improvement in periodontal parameters over time, except for probing depth and attachment level, which had a slight mean increase of 0.2 mm (p < .01). No significant differences between groups were observed for any clinical parameter (p > .05). Most species (>65%) decreased similarly in levels in both groups over time. Significant reductions in the microbial complexes were seen mainly at 1 and 3 months, but they returned to baseline levels in both groups, except for the red and yellow complexes, and other oral species, which were kept in low levels at 6 months (p < .05). A 0.1% NaOCl mouthwash did not provide additional benefits to FMUD in reducing supragingival plaque, gingivitis, and/or microbial pathogens.

Long-term evaluation of the antimicrobial susceptibility and microbial profile of subgingival biofilms in individuals with aggressive periodontitis.

This study evaluates the antimicrobial susceptibility and composition of subgingival biofilms in generalized aggressive periodontitis (GAP) patients treated using mechanical/antimicrobial therapies, including chlorhexidine (CHX), amoxicillin (AMX) and metronidazole (MET). GAP patients allocated to the placebo (C, n = 15) or test group (T, n = 16) received full-mouth disinfection with CHX, scaling and root planning, and systemic AMX (500 mg)/MET (250 mg) or placebos. Subgingival plaque samples were obtained at baseline, 3, 6, 9 and 12 months post-therapy from 3-4 periodontal pockets, and the samples were pooled and cultivated under anaerobic conditions. The minimum inhibitory concentrations (MICs) of AMX, MET and CHX were assessed using the microdilution method. Bacterial species present in the cultivated biofilm were identified by checkerboard DNA-DNA hybridization. At baseline, no differences in the MICs between groups were observed for the 3 antimicrobials. In the T group, significant increases in the MICs of CHX (p < 0.05) and AMX (p < 0.01) were detected during the first 3 months; however, the MIC of MET decreased at 12 months (p < 0.05). For several species, the MICs significantly changed over time in both groups, i.e., Streptococci MICs tended to increase, while for several periodontal pathogens, the MICs diminished. A transitory increase in the MIC of the subgingival biofilm to AMX and CHX was observed in GAP patients treated using enhanced mechanical therapy with topical CHX and systemic AMX/MET. Both protocols presented limited effects on the cultivable subgingival microbiota.

Long-term evaluation of the antimicrobial susceptibility and microbial profile of subgingival biofilms in individuals with aggressive periodontitis

This study evaluates the antimicrobial susceptibility and composition of subgingival biofilms in generalized aggressive periodontitis (GAP) patients treated using mechanical/antimicrobial therapies, including chlorhexidine (CHX), amoxicillin (AMX) and metronidazole (MET). GAP patients allocated to the placebo (C, n = 15) or test group (T, n = 16) received full-mouth disinfection with CHX, scaling and root planning, and systemic AMX (500 mg)/MET (250 mg) or placebos. Subgingival plaque samples were obtained at baseline, 3, 6, 9 and 12 months post-therapy from 3–4 periodontal pockets, and the samples were pooled and cultivated under anaerobic conditions. The minimum inhibitory concentrations (MICs) of AMX, MET and CHX were assessed using the microdilution method. Bacterial species present in the cultivated biofilm were identified by checkerboard DNA-DNA hybridization. At baseline, no differences in the MICs between groups were observed for the 3 antimicrobials. In the T group, significant increases in the MICs of CHX (p < 0.05) and AMX (p < 0.01) were detected during the first 3 months; however, the MIC of MET decreased at 12 months (p < 0.05). For several species, the MICs significantly changed over time in both groups, i.e., Streptococci MICs tended to increase, while for several periodontal pathogens, the MICs diminished. A transitory increase in the MIC of the subgingival biofilm to AMX and CHX was observed in GAP patients treated using enhanced mechanical therapy with topical CHX and systemic AMX/MET. Both protocols presented limited effects on the cultivable subgingival microbiota.

Antimicrobial efficacy of the EndoVac system plus PDT against intracanal Candida albicans: an ex vivo study.

This study evaluated the ex vivoantimicrobial efficacy of the EndoVac system and the photodynamic therapy (PDT) associated with chemomechanical debridement (CMD) and intracanal medication on Candida albicans. Seventy-eight sterile premolars were contaminated withC. albicans (ATCC 21433) for 30 days. The teeth were randomly assigned into four groups: Control (CMD with conventional irrigation); Endovac (CMD with EndoVac system); PDT (CMD with conventional irrigation and PDT); and Endovac + PDT (CMD with EndoVac and PDT). After the therapies, intracanal dressing (calcium hydroxide) was applied to all teeth for seven days. Samples were obtained before (T1) and after the therapeutic procedures (T2), and after intracanal medication (T3), plated onto BHI agar and incubated (37°C, 48 h) to determine the colony-forming units (CFU)/mL. The overall mean level ofC. albicans at baseline was relatively high (1.85 x 106 ± 2.7 x 106 CFU mL-1). A significant reduction of C. albicans(p < 0.05) was observed over time (T1 to T2 and T1 to T3) in all groups. An additional significant reduction from T2 to T3 was observed only in the Endovac group (p < 0.05). No differences in mean reduction of C. albicans were observed among groups. However, the Endovac group presented the lowest mean counts of C. albicans at T3, whereas the PDT group had the highest counts of this microorganism (p < 0.05). The EndoVac system of irrigation/aspiration associated with CMD was the most effective therapeutic protocol for reducing intracanal levels of C. albicans. PDT showed a very limited efficacy against this species.

Estudo comparativo da atividade antimicrobiana "in vivo" de seis antissépticos bucais sobre a microbiota da saliva / A comparative in vitro study of antimicrobial activity of six commercial mouthwashes against salivary bacteria

Introdução: Soluções de antissépticos bucais podem desempenhar importante papel no controle químico do biofilme dentário. No entanto, os procedimentos de controle de qualidade relacionados com a atividade antimicrobiana destes enxaguatórios contra bactérias da cavidade oral não são bem divulgados. Objetivo: Avaliar a atividade antimicrobiana in vivo de seis soluções de antissépticos bucais disponíveis no mercado brasileiro, empregadas como enxaguatórios contra bactérias da saliva humana. Material e métodos: Um estudo in vivo foi desenvolvido com indivíduos voluntários (8 do sexo masculino e 7 do sexo feminino, variando de 18 a 63 anos de idade ), independente do estado de saúde bucal. Os seguintes produtos comerciais foram testados durante 2 horas após um único procedimento de bochecho: 1) Plax®, 2) Listerine®, 3) Periogard®, 4) Cepacol®, 5) Sanifill Premium® e 6) Oral B®.Os resultados foram analisados pelo teste de ANOVA de medidas repetidas e ANOVA one-way com um nível de significância de 5%. Resultados: Houve diferença significativa (p <0,05) observada na diminuição da carga microbiana para Plax® entre o início (antes anti-séptico bucal) e imediatamente após o bochecho (T0); para Periogard® entre os valores iniciais e T60 (60 minutos após o bochecho), na linha de base e T120 (120 minutos após o bochecho) e B® Oral entre os valores iniciais e T-30 (30 minutos após o bochecho). Periogard® apresentou a maior redução da carga microbiana salivares. Conclusão: Dos seis bochechos testados, Plax®, Oral B® e Periogard ® apresentou atividade antibacteriana imediata. Periogard® foi o anti-séptico bucal que mostrou a atividade mais prolongada contra bactérias anaeróbias salivares (AU).

Introduction: Mouthwashes solutions can play an important role in the chemical control of dental biofilm. However, quality control procedures related to antimicrobial activity of these solutions against oral bacteria are not well known. Objective: To evaluate in vivo antimicrobial activity of six mouthwashes solutions available in the Brazilian market against anaerobic salivary bacteria. Material and methods: An in vivo study was developed in human volunteers (8 male and 7 female, ranging from 18 to 63 years old), despite their oral health status. The following commercial products were tested after 2 hours of a single mouthwash procedure: 1) Plax®, 2) Listerine®, 3) Periogard®, 4) Cepacol®, 5) Sanifill Premium® and 6)Oral B®. Data were analyzed by ANOVA to repeated measures and ANOVA one-way with a significance level of 5%. Results: Statistically significant difference (p<0.05) was observed in the decrease of microbial counts to Plax® between baseline (before mouthwash) and immediately after mouthwash (T0); to Periogard® between baseline and T60 (60 minutes after mouthwash), baseline and T120 (120 minutes after mouthwash) and to Oral B® between baseline and T-30 (30 minutes after mouthwash). Periogard® showed the highest and delayed reduction of salivary microbial counts. Conclusion: Out of six tested mouthwashes, Plax®, Oral B® and Periogard ® showed immediate antibacterial activity. Periogard® was the oral anti-septic that showed the best delayed activity against salivary anaerobic bacteria (AU).

Antimicrobial efficacy of the EndoVac system plus PDT against intracanal Candida albicans: an ex vivo study

This study evaluated the ex vivoantimicrobial efficacy of the EndoVac system and the photodynamic therapy (PDT) associated with chemomechanical debridement (CMD) and intracanal medication on Candida albicans. Seventy-eight sterile premolars were contaminated withC. albicans (ATCC 21433) for 30 days. The teeth were randomly assigned into four groups: Control (CMD with conventional irrigation); Endovac (CMD with EndoVac system); PDT (CMD with conventional irrigation and PDT); and Endovac + PDT (CMD with EndoVac and PDT). After the therapies, intracanal dressing (calcium hydroxide) was applied to all teeth for seven days. Samples were obtained before (T1) and after the therapeutic procedures (T2), and after intracanal medication (T3), plated onto BHI agar and incubated (37°C, 48 h) to determine the colony-forming units (CFU)/mL. The overall mean level ofC. albicans at baseline was relatively high (1.85 x 106 ± 2.7 x 106 CFU mL-1). A significant reduction of C. albicans(p < 0.05) was observed over time (T1 to T2 and T1 to T3) in all groups. An additional significant reduction from T2 to T3 was observed only in the Endovac group (p < 0.05). No differences in mean reduction of C. albicans were observed among groups. However, the Endovac group presented the lowest mean counts of C. albicans at T3, whereas the PDT group had the highest counts of this microorganism (p < 0.05). The EndoVac system of irrigation/aspiration associated with CMD was the most effective therapeutic protocol for reducing intracanal levels of C. albicans. PDT showed a very limited efficacy against this species.