Periodontal status, vascular reactivity, and platelet aggregation changes in rats submitted to hypercholesterolemic diet and periodontitis.

BACKGROUND AND OBJECTIVES: Periodontitis can corroborate with development and progression of atherosclerosis and a possible bidirectional interaction between both pathologies has been hypothesized. The aim of this work was to study the interactions between diet-induced hypercholesterolemia and ligature-induced periodontitis in Wistar rats submitted to both conditions. MATERIAL AND METHODS: Animals were divided into four experimental groups: C (control: standard diet without periodontitis), Perio (periodontitis plus standard diet), HC (high cholesterol diet without periodontitis), and HC + Perio (high cholesterol diet plus periodontitis). The diets were offered for 45 days and a silk ligature was applied in the lower first molars of Perio and HC-Perio animals on day 34 and maintained for 11 days until euthanasia. The mandibles were excised, and alveolar bone loss was determined by macroscopic and micro-tomographic (µ-CT) imaging. Blood samples were obtained, and platelet aggregation was induced in plasma rich in platelets by adenosine diphosphate (ADP) and collagen. Endothelium-dependent vascular reactivity and protein expression of endothelial (eNOS), phosphorylated endothelial (peNOS), and inducible (iNOS) nitric oxide synthases were evaluated in aorta samples. RESULTS: The HC diet combined with periodontitis (HC + Perio group) was associated with an increased alveolar bone loss, when compared to the other groups. Both in Perio and HC groups, platelet aggregation induced by ADP or collagen was increased, while maximum aortic relaxation induced by acetylcholine was decreased. Periodontitis or HC diet alone decreased the expression of peNOS and HC diet increased the expression of iNOS. In contrast, no additive or synergistic effects were found in vascular reactivity or in platelet aggregation when the two conditions were associated (HC + Perio group). CONCLUSION: Hypercholesterolemia accelerated the process of bone loss induced by periodontitis while a high cholesterol diet or periodontitis individually increased platelet aggregation and vascular reactivity in rats without additive or synergistic effects, when associated.

Subgingival microbiota in overweight and obese young adults with no destructive periodontal disease.

BACKGROUND: This study analyzed the levels of a specific group of periodontal health/disease-related oral bacteria in the subgingival biofilm of young adults with overweight (OW) and obesity (OB), and no destructive periodontal disease. METHODS: Full-mouth periodontal assessment and subgingival biofilm sampling were performed in individuals with normal weight (NW) (BMI [body mass index] ≥18.5 to ≤24.9 kg/m2 ; n = 29), OW (BMI ≥25 to ≤29.9 kg/m2 ; n = 26), or OB (BMI ≥30 kg/m2 ; n = 22). BMI, waist (WC) and hip (HC) circumferences, and waist-hip ratio (WHR) were established for every individual. Biofilm samples were analyzed by checkerboard. Spearman coefficient, linear, and logistic regression analyses were obtained. RESULTS: Gingivitis was detected in 45% NW, 65% OW, and 73% OB individuals. NW patients presented significantly less calculus and supragingival biofilm than OB. OW, and OB individuals had significantly higher levels of Porphyromonas gingivalis and Tannerella forsythia than NW patients (P <0.05). Treponema denticola correlated with BMI (rho = 0.31), WC (rho = 0.28), and HC (rho = 0.29), P≤0.01. Linear regression analysis showed significant (P <0.05) positive associations between BMI, WC, HC, and WHR indicators and Prevotella spp., Lactobacillus spp., V. parvula, and A. actinomycetemcomitans (Aa); negative associations were found between Capnocytophaga spp., WC, and HC (ß = -0.29 and ß = -0.37, respectively; P <0.01). However, the interaction of Prevotella spp. and T. forsythia decreased the likelihood of an individual to be diagnosed as OW/OB (OR 0.183 [95% CI, 0.062-0.540]). CONCLUSIONS: Few periodontal pathogens differed in levels between NW and OW/OB individuals without destructive periodontal disease. Moreover, Aa, T. denticola, and Prevotella spp. were associated with clinical parameters of obesity.

Antimicrobial susceptibility and virulence of Enterococcus spp. isolated from periodontitis-associated subgingival biofilm.

BACKGROUND: This study evaluated the prevalence, virulence and antimicrobial susceptibility of enterococci isolated from the subgingival microbiota of patients with different periodontal status. METHODS: Subgingival biofilm was obtained from individuals with periodontal health (PH) (n = 139), gingivitis (n = 103), and periodontitis (n = 305) and cultivated on selective media. Isolated strains were identified by mass spectrometry. Antimicrobial sensitivity was determined by disk diffusion, virulence genes by polymerase chain reaction, and the subgingival microbiota by checkerboard. Differences among groups were assessed by Kruskal-Wallis, Mann-Whitney, and Chi-square tests. RESULTS: Enterococcus spp. were isolated from 7.4% of all samples; 53.7% were Enterococcus faecalis. They were more prevalent in periodontitis (9.8%) and gingivitis (7.8%) than PH (2.2%; P <0.05), but no differences among stages of disease severity were observed. High rates of low susceptibility/resistance (>64%) to at least one antimicrobial were observed. Predominant virulence factors included ace (64.3%), asa (39.3%), and esp (35.7%). Fusobacterium nucleatum was prevalent in the subgingival microbiota of enterococci+ individuals, whereas Dialister pneumosintes was found in low frequency in patients with bopD+ enterococci. Oral streptococci were prevalent (>70%) in patients carrying enterococci susceptible to doxycycline (P <0.05), usually bopD- and esp- (P <0.01). CONCLUSIONS: E. faecalis is increased in periodontitis-associated biofilm. Oral enterococci carry virulence genes and express resistance to some antibiotics commonly used in dentistry, such as ciprofloxacin and erythromycin. Specific subgingival taxa are associated with oral enterococci, suggesting they may interact with species of the dysbiotic periodontitis biofilm, constituting a potential source of factors to tissue destruction, antibiotic resistance dissemination, and poor response to periodontal therapy.

Effects of ultrasonic, electric, and manual toothbrushes on subgingival plaque composition in orthodontically banded molars.

INTRODUCTION: Orthodontic appliances hinder mechanical plaque control. In this study, we evaluated the effect of self-performed supragingival plaque removal with ultrasonic, electric, and manual toothbrushes on subgingival plaque composition in orthodontically banded molars. METHODS: Twenty-one patients wearing fixed orthodontic appliances were assigned to this single-blind crossover study. Samples of subgingival plaque were collected from banded molars, before and after each toothbrush usage period, for quantification of 22 bacterial species by the checkerboard DNA-DNA hybridization method. For each crossover, patients used a toothbrush for 30 days, followed by a washout period of 14 days. RESULTS: The prevalence of Tannerella forsythia decreased significantly after a month of electric brush usage. In the manual brush group, the prevalences of Selenomonas noxia, Streptococcus sanguinis, and Prevotella melaninogenica also decreased significantly. However, there were no significant differences in the prevalences and levels of bacteria after usage of the ultrasonic brush. Intergroup comparisons showed no statistical differences among the 3 brushes for the microbiologic parameters. CONCLUSIONS: All 3 brushes generally reduced bacterial prevalences, and, although electric and manual toothbrushes showed some isolated significant variations, we found no superiority with any toothbrush type when used three times daily for 2 minutes on microbiologic parameters in orthodontically banded molars.

Comparisons of subgingival microbial profiles of refractory periodontitis, severe periodontitis, and periodontal health using the human oral microbe identification microarray.

BACKGROUND: This study compared the subgingival microbiota of subjects with refractory periodontitis (RP) to those in subjects with treatable periodontitis (GRs = good responders) or periodontal health (PH) using the Human Oral Microbe Identification Microarray (HOMIM). METHODS: At baseline, subgingival plaque samples were taken from 47 subjects with periodontitis and 20 individuals with PH and analyzed for the presence of 300 species by HOMIM. The subjects with periodontitis were classified as having RP (n = 17) based on mean attachment loss (AL) and/or more than three sites with AL >or=2.5 mm after scaling and root planing, surgery, and systemically administered amoxicillin and metronidazole or as GRs (n = 30) based on mean attachment gain and no sites with AL >or=2.5 mm after treatment. Significant differences in taxa among the groups were sought using the Kruskal-Wallis and chi(2) tests. RESULTS: More species were detected in patients with disease (GR or RP) than in those without disease (PH). Subjects with RP were distinguished from GRs or those with PH by a significantly higher frequency of putative periodontal pathogens, such as Parvimonas micra (previously Peptostreptococcus micros or Micromonas micros), Campylobacter gracilis, Eubacterium nodatum, Selenomonas noxia, Tannerella forsythia (previously T. forsythensis), Porphyromonas gingivalis, Prevotella spp., Treponema spp., and Eikenella corrodens, as well as unusual species (Pseudoramibacter alactolyticus, TM7 spp. oral taxon [OT] 346/356, Bacteroidetes sp. OT 272/274, Solobacterium moorei, Desulfobulbus sp. OT 041, Brevundimonas diminuta, Sphaerocytophaga sp. OT 337, Shuttleworthia satelles, Filifactor alocis, Dialister invisus/pneumosintes, Granulicatella adiacens, Mogibacterium timidum, Veillonella atypica, Mycoplasma salivarium, Synergistes sp. cluster II, and Acidaminococcaceae [G-1] sp. OT 132/150/155/148/135) (P <0.05). Species that were more prevalent in subjects with PH than in patients with periodontitis included Actinomyces sp. OT 170, Actinomyces spp. cluster I, Capnocytophaga sputigena, Cardiobacterium hominis, Haemophilus parainfluenzae, Lautropia mirabilis, Propionibacterium propionicum, Rothia dentocariosa/mucilaginosa, and Streptococcus sanguinis (P <0.05). CONCLUSION: As determined by HOMIM, patients with RP presented a distinct microbial profile compared to patients in the GR and PH groups.

Manual and electronic probing of the periodontal attachment level in untreated periodontitis: a systematic review.

OBJECTIVE: A systematic review of clinical trials has been performed to evaluate the reproducibility of manual (MP) and electronic probes (EP) in the measurement of clinical periodontal attachment level (AL) in untreated periodontitis subjects. METHODS: Systematic electronic (PubMed Medline and Latin American and Caribbean Health Science--LILACS literature databases) and hand searches (English, Spanish and Portuguese languages; search terms "periodontitis diagnosis", "clinical attachment level measurements", "clinical attachment level detection", "clinical diagnosis of periodontitis", "manual probe", "electronic probe", "periodontitis or periodontal disease or attachment level or clinical attachment level") were performed to identify clinical trials involving CAL measurements, MP and EP in untreated periodontitis subjects. Quality and external validity were determined for selected studies. RESULTS: The initial search identified 37 articles. Ten studies met the initial eligibility, but eight were excluded after thorough analysis. The results from those two selected studies showed that the average variance and the absolute mean difference of CAL measurements for both types of probes cannot be considered different. CONCLUSION: "Based on this systematic review, MP and EP probes showed a tendency to have similar reliability in the measurement of CAL in untreated periodontitis subjects when used by a calibrated examiner. However, this finding is not supported by strong evidence.

Salivary microbiota of HIV-positive children and its correlation with HIV status, oral diseases, and total secretory IgA.

AIM: This study aimed to investigate the prevalence and levels of salivary microorganisms in HIV-positive children, and their correlation to HIV status, oral lesions, and salivary IgA levels. DESIGN: Forty-two HIV-positive and 36 control children were clinically examined, had their saliva collected and processed for the microbiological analysis of 38 bacterial taxa by the checkerboard method, and salivary IgA quantification by ELISA. RESULTS: The majority of the species tested were more prevalent in control children than in the HIV group. Mean concentration of total salivary IgA was similar in both groups. High levels of Veillonella parvula were found in children with cheilitis and herpes. Tannerella forsythia, Eikenella Corrodens, and Propionibacterium acnes were prevalent in children with gingivitis, while Fusobacterium periodonticum, Streptococcus gordonii, and Streptococcus oralis were significantly more frequent in children with no oral lesions. Significant negative correlations between salivary IgA levels and Eubacterium nodatum and oral streptococci were observed (P < 0.05). CONCLUSION: HIV-seropositive children presented significantly lower prevalence and levels of several bacterial species in saliva; HIV-positive children are able to mount a mucosal immune response; HIV-seropositive children under highly active antiretroviral therapy presented low prevalence of oral lesions.

Subgingival microbial profile of obese women with periodontal disease.

BACKGROUND: This study compared the composition of subgingival microbiota between obese and non-obese women with or without periodontal disease. METHODS: Full-mouth periodontal clinical assessments were carried out in 76 obese women (17 periodontally healthy and 59 with periodontal disease), and 34 non-obese women (12 periodontally healthy, 22 with periodontal disease). Subgingival biofilm samples were individually obtained from seven sites of each individual, and the prevalence and counts of 40 bacterial taxa were determined by the checkerboard method. The frequency and counts of each species were computed for each individual and across the groups. Differences among and between groups were sought by the Kruskal-Wallis and Mann-Whitney tests, respectively. Possible correlations between obesity and clinical and microbiologic parameters were tested with Spearman correlation coefficient. RESULTS: Streptococcus sanguinis, Streptococcus oralis, and Capnocytophaga ochracea were found in significantly higher levels in obese compared with non-obese women (P < 0.01). In patients with periodontal health, Porphyromonas gingivalis and Leptotrichia buccalis were detected in higher mean frequency and/or counts in obese women than in non-obese women, whereas in patients with periodontal disease, obese women harbored greater levels of C. ochracea than non-obese women (P < 0.01). Moreover, obese women with periodontal disease presented significantly greater mean counts of P. gingivalis and Tannerella forsythia than non-obese women with periodontal health (P < 0.01). When the conditions obesity and periodontal disease are present at the same time, significant positive correlations were detected with C. ocharcea, P. gingivalis, S. sanguinis, and T. forsythia. CONCLUSION: Few differences in the composition of the subgingival microbiota of obese and non-obese women with periodontal health or disease were found. However, a high prevalence of P. gingivalis in obese women with periodontal health was observed.

IL-1 gene polymorphism and periodontal status of HIV Brazilians on highly active antiretroviral therapy.

A genotype in the IL-1 gene cluster is associated with an increased risk of periodontitis. We investigated whether polymorphisms in the IL-1A +4845 and IL-1B +3954 loci affect the periodontal status of HIV-infected Brazilians on HAART. HIV-positive and HIV-negative subjects with periodontitis were genotyped for IL-1 by polymerase chain reaction and restriction enzyme digestion. Only 11.4% of patients were genotype positive. No associations between genotype positivity and HIV infection or periodontal status were found in this population.

Distribution of FcgammaRIIa and FcgammaRIIIb genotypes in patients with generalized aggressive periodontitis.

BACKGROUND: Polymorphisms in FcgammaR have been associated with different forms of periodontitis. This study determined the frequency of FcgammaRIIa and FcgammaRIIIb alleles/genotypes in patients with generalized aggressive periodontitis (GAgP). METHODS: Thirty-one GAgP and 49 periodontally healthy Brazilian subjects participated in the study. Full-mouth periodontal examinations were carried out, and mouthwash samples were collected for human DNA isolation. FcgammaR genotyping was performed by polymerase chain reaction and hybridization with allele-specific oligonucleotide probes. Significant differences between groups were sought by Mann-Whitney, chi2, and Fisher exact tests and configural frequency analysis. RESULTS: FcgammaRIIa-H131 (53.8%) and FcgammaRIIIb-NA1 (75%) were the most prevalent alleles in this sample population. A significant overrepresentation of FcgammaRIIIb-NA2 was observed in the GAgP group, whereas FcgammaRIIIb-NA1 was detected more often in healthy individuals (odds ratio, 32.5; 95% confidence interval [CI], 10.6 to 99.8; P<0.001). No significant differences in the distribution of the FcgammaRIIa genotypes were observed between the groups. The prevalence of FcgammaRIIIb-NA2/NA2 was higher in GAgP patients, whereas FcgammaRIIIb-NA1/NA1 was predominant in the healthy group (chi2=45.1; P<0.001). The combination of the genotypes FcgammaRIIIb-NA2/NA2 plus FcgammaRIIa-H/H131 was observed more frequently in GAgP subjects than expected from marginal frequencies (chi2=12.5; P<0.001). CONCLUSIONS: The data suggest that the FcgammaRIIIb-NA2 allele and/or FcgammaRIIIb-NA2/NA2 genotype and the composite genotype FcgammaRIIIb-NA2/NA2 plus FcgammaRIIa-H/H131 may be associated with GAgP, whereas FcgammaRIIIb-NA1 and/or FcgammaRIIIb-NA1/NA1 may be related to periodontal health in this sample of the Brazilian population.

Evaluation of metronidazole-loaded poly(3-hydroxybutyrate) membranes to potential application in periodontitis treatment.

Guided tissue regeneration is a technique used for periodontium reconstruction. This technique uses barrier membranes, which prevent epithelial growth in the wound site and may also be used to release antibiotics, to protect the wound against opportunistic infections. Periodontal poly(3-hydroxybutyrate) membranes containing metronidazole (a drug used to help in infection control) were produced and characterized. The kinetic mechanism of the metronidazole delivery of leached and nonleached membrane as well as its cytotoxicity and structural integrity were evaluated. Poly(3-hydroxybutyrate) membranes containing 0.5-2 wt % of the drug and 20 wt % of the plasticizer were manufactured via compression molding. Based on morphological analysis, membranes loaded with 2% metronidazole were considered for detailed studies. The results revealed that metronidazole delivery by the leached membranes seemed to follow the Fick's law. Membranes were noncytotoxic. The amount of metronidazole delivered was in the range of the minimal inhibitory concentration for Porphyromonas gingivalis, and the membranes inhibited the proliferation of these bacteria. Besides, they maintained their mechanical resistance after 30 days of immersion in phosphate buffer at pH 7.4.

Subgingival microbiota of Brazilian subjects with untreated chronic periodontitis.

BACKGROUND: Different periodontopathogenic microbiota have been associated with periodontal diseases in several populations. The present investigation determined the subgingival microbiota of untreated chronic periodontitis Brazilians using the checkerboard DNA-DNA hybridization technique. METHODS: Twenty-five periodontitis patients (mean age, 41 +/- 2; mean probing depth [PD], 3.3 +/- 0.2; mean attachment level [AL], 3.6 +/- 0.2) with no history of previous periodontal therapy and a control group of 14 healthy subjects (mean age, 34 +/- 0.6; mean PD, 1.8 +/- 0.2; mean AL, 1.7 +/- 0.1) were selected. Measurements of PD, AL, bleeding on probing, plaque accumulation, and suppuration were recorded at 6 sites/tooth. Subgingival plaque samples were obtained from 4 sites in each tooth/subject in both groups. The presence and levels of 41 subgingival species were determined in 4,032 plaque samples using whole genomic DNA probes and the checkerboard method. RESULTS: Periodontal pathogens, as well as some unusual species (E. faecalis, E. coli and Bartonella sp.), were detected significantly more often and/or in higher levels in the periodontitis group (P < 0.05). Most species were more frequently detected in interproximal sites. B. forsythus, P. gingivalis, E. nodatum, and F. nucleatum ss vincentii showed a significant positive correlation with mean PD and AL (P < 0.05). CONCLUSIONS: The subgingival microbiota of Brazilians with untreated chronic periodontitis were complex, including high proportions of periodontopathogens commonly found in other populations, as well as some unusual species.

Suppuration-associated bacteria in patients with chronic and aggressive periodontitis.

BACKGROUND: Suppuration (SUP) on probing may be an indication of active periodontal breakdown. The aim of the present study is to analyze which subgingival species are associated with SUP in patients with chronic (CP) and aggressive (AgP) periodontitis. METHODS: A total of 156 patients with CP and 66 with AgP were submitted to full-mouth periodontal examination and subgingival biofilm sampling (14 sites/patient). The counts of 44 bacterial species were determined by checkerboard. Comparisons between groups and sites were analyzed by the Mann-Whitney and Wilcoxon tests, respectively. Associations between frequency of SUP and bacterial species were analyzed by the Spearman correlation coefficient. RESULTS: The prevalence of SUP in patients with CP was 24.4%, and in patients with AgP it was 30.3%, and the percentage of SUP sites in the groups was 5.72% ± 1.06% and 6.96% ± 1.70%, respectively (P >0.05). SUP sites from patients with CP had significantly higher counts of Veillonella parvula, Dialister pneumosintes, Tannerella forsythia, and Prevotella nigrescens than SUP sites from patients with AgP (P <0.005). Significant positive correlations between high frequency of SUP and high levels of Actinomyces spp, Streptococcus spp., members of the orange complex, Acinetobacter baumannii, and Pseudomonas aeruginosa were observed in patients with CP (P <0.05). In patients with AgP, Actinomyces oris, Propionibacterium acnes, P. aeruginosa, Staphylococcus aureus, and Streptococcus sanguinis were positively associated with SUP, whereas Prevotella intermedia presented a negative association with SUP (P <0.05). CONCLUSIONS: SUP sites from patients with CP harbored significantly higher counts of several periodontal species than SUP sites from patients with AgP. Actinomyces spp., Streptococcus spp., members of the orange complex, T. forsythia, and certain non-oral pathogens were associated with a high number of sites with SUP.

Quantitative proteomic analysis of gingival crevicular fluid in different periodontal conditions.

AIM: To quantify the proteome composition of the GCF in periodontal health (HH) and in sites with different clinical conditions in chronic periodontitis (CP) subjects. MATERIAL AND METHODS: 5 subjects with HH and 5 with CP were submitted to full-mouth periodontal examination, and GCF sampling. Sites in the CP group were classified and sampled as periodontitis (P, probing depth, PD>4 mm), gingivitis (G, PD≤3 mm with bleeding on probing, BOP), and healthy sites (H, PD≤3 mm without BOP). GCF proteins were subjected to liquid chromatography electrospray ionization mass spectrometry for identification, characterization and quantification. RESULTS: 230 proteins were identified; 145 proteins were detected in HH, 214 in P, 154 in G, and 133 in H. Four proteins were exclusively detected at HH, 43 proteins at P, 7 proteins at G, and 1 protein at H. Compared to HH group, 35 and 6 proteins were more abundant in P and G (p<0.001), respectively; and 4, 15 and 37 proteins were less abundant in P, G and H (p≤0.01), respectively. CONCLUSIONS: There are marked differences in the GCF proteome according to disease profile. Comprehension of the role of the identified proteins in the etiopathogenesis of periodontal disease may lead to biomarkers definition.

Impact of periodontal therapy on the subgingival microbiota of severe periodontitis: comparison between good responders and individuals with refractory periodontitis using the human oral microbe identification microarray.

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

Systemic antimicrobials adjunctive to a repeated mechanical and antiseptic therapy for aggressive periodontitis: a 6-month randomized controlled trial.

BACKGROUND: The purpose of this study is to compare the additional benefit of systemic antimicrobials versus placebos to a repeated mechanical instrumentation combined with comprehensive local chemical plaque control for the periodontal treatment of generalized aggressive periodontitis (GAgP). METHODS: This was a 6-month randomized, double-masked, placebo-controlled clinical trial. All GAgP patients received full-mouth disinfection followed by staged scaling and root planing without (placebo group; n = 17) or with (test group; n = 18) systemic antimicrobials (500 mg amoxicillin [AMX] + 250 mg metronidazole [MET]; three times a day for 10 days). Clinical parameters were measured at baseline and 3 and 6 months post-therapy. Significant differences between groups at baseline were sought by using the Mann-Whitney U test, whereas comparisons over time were examined by using a general linear model repeated measures procedure. RESULTS: Both groups demonstrated similar improvements in most parameters over time. The test group presented a greater mean probing depth (PD) reduction and clinical attachment level (CAL) gain at sites with initially moderate PD at 6 months (P <0.03). No differences were seen between groups regarding mean reductions and mean gains, respectively, for PD and CAL initially ≥7 mm. The test group presented a higher percentage of sites that improved ≥2 mm and ended up with PD ≤4 mm or a lower percentage of sites that worsened ≥2 mm and remained with PD >4 mm at 3 months (P <0.01). No differences were noticed between groups for these parameters at 6 months. CONCLUSION: AMX + MET brought additional clinical effects to the repeated mechanical and antiseptic treatment of GAgP in a very short time (3 months), which tended to fade away over time (6 months).

Adsorption of chlorhexidine on synthetic hydroxyapatite and in vitro biological activity.

The kinetic of chlorhexidine digluconate (CHXDG) uptake from aqueous solution by hydroxyapatite (HA) was investigated by ultraviolet (UV) analysis performed in HA powder (UV-solid) after the CHX adsorption. Adsorption isotherm of chlorhexidine (CHX) uptake was modeled by a combination of Languimir and Langmuir-Freundlich mechanisms. Strong molecule-molecule interactions and positive cooperativity predominated in the surface when CHX concentration was above 8.6 µg(CHX)/mg(HA). UV-solid spectra (shape, intensity and band position) of CHX bound to HA revealed that long-range molecular structures, such as aggregates or micelles, started to be formed at low CHX concentrations (1.52 µg(CHX)/mg(HA)) and predominated at high concentrations. Grazing-incidence X-ray diffraction (GIXRD) analysis from synchrotron radiation discarded the formation of crystalline structures on HA surface or precipitation of CHX crystalline salts, as suggested in previous works. The effect of the HA/CHX association on HA in vitro bioactivity, cytotoxicity and CHX antimicrobial activity was evaluated. It was shown that CHX did not inhibit the precipitation of a poorly crystalline apatite at HA/CHX surface after soaking in simulating body fluid (SBF). Cell viability studies after exposure to extracts of HA and HA/CHX showed that both biomaterials did not present significant in vitro toxicity. Moreover, HA/CHX inhibited Enterococcus faecalis growth for up to 6 days, revealing that binding to HA did not affect antimicrobial activity of CHX and reduced bacterial adhesion. These results suggested that HA/CHX association could result in a potential adjuvant antimicrobial system for clinical use.

Periodontal status, sociodemographic, and behavioral indicators in subjects attending a public dental school in Brazil: analysis of clinical attachment loss.

BACKGROUND: The purpose of this study was to assess the prevalence, extent, and severity of clinical attachment loss (AL) and their association with sociodemographic and behavioral parameters of subjects attending a public dental school in Brazil. METHODS: A total of 491 consenting participants (21 to 70 years of age) submitted to a full-mouth periodontal clinical examination, assessment of missing teeth, and anamnesis questionnaires. The data were analyzed by multivariable models using logistic regression analyses. The dependent variables were moderate (> or =5 mm) and severe (> or =7 mm) clinical AL. RESULTS: The prevalence of individuals with at least one site with clinical AL > or =5 or > or =7 mm was 72.1% and 60.9%, respectively. The mean clinical AL ranged from 2.9 to 3.9 mm, according to age. The mean frequency of sites with moderate (5 to 6 mm) and severe (> or =7 mm) clinical AL was 15.8% and 9.1%, respectively. Multivariate analyses identified smoking (odds ratio [OR] = 8.93), bleeding on probing (BOP) in >10% of sites (OR = 6.82 to 22.53), and > or =4 missing teeth (OR = 2.52) as risk indicators for clinical AL > or =5 mm in > or =10% of sites, whereas an age of 36 to 50 years (OR = 1.72), smoking (OR = 7.66), and BOP in >10% of sites (OR = 6.84 to 24.89) were considered risk indicators for clinical AL > or =7 mm in at least one site. CONCLUSIONS: This particular Brazilian population presented a high prevalence and extent of severe periodontal disease. Age, smoking, and BOP were risk indicators associated with moderate and severe AL in this population.

Distribution of FcγRIIa and FcγRIIIb Genotypes in Patients With Generalized Aggressive Periodontitis.

BACKGROUND: Polymorphisms in FcγR have been associated with different forms of periodontitis. This study determined the frequency of FcγRIIa and FcγRIIIb alleles/genotypes in patients with generalized aggressive periodontitis (GAgP). METHODS: Thirty-one GAgP and 49 periodontally healthy Brazilian subjects participated in the study. Full-mouth periodontal examinations were carried out, and mouthwash samples were collected for human DNA isolation. FcγR genotyping was performed by polymerase chain reaction and hybridization with allele-specific oligonucleotide probes. Significant differences between groups were sought by Mann-Whitney, χ2 , and Fisher exact tests and configural frequency analysis. RESULTS: FcγRIIa-H131 (53.8%) and FcγRIIIb-NA1 (75%) were the most prevalent alleles in this sample population. A significant overrepresentation of FcγRIIIb-NA2 was observed in the GAgP group, whereas FcγRIIIb-NA1 was detected more often in healthy individuals (odds ratio, 32.5; 95% confidence interval [CI], 10.6 to 99.8; P <0.001). No significant differences in the distribution of the FcγRIIa genotypes were observed between the groups. The prevalence of FcγRIIIb-NA2/NA2 was higher in GAgP patients, whereas FcγRIIIb-NA1/NA1 was predominant in the healthy group (χ2 = 45.1; P <0.001). The combination of the genotypes FcγRIIIb-NA2/NA2 plus FcγRIIa-H/H131 was observed more frequently in GAgP subjects than expected from marginal frequencies (χ2 = 12.5; P <0.001). CONCLUSIONS: The data suggest that the FcγRIIIb-NA2 allele and/or FcγRIIIb-NA2/NA2 genotype and the composite genotype FcγRIIIb-NA2/NA2 plus FcγRIIa-H/H131 may be associated with GAgP, whereas FcγRIIIb-NA1 and/or FcγRIIIb-NA1/NA1 may be related to periodontal health in this sample of the Brazilian population.

Antibiotic resistance profile of the subgingival microbiota following systemic or local tetracycline therapy.

BACKGROUND: Tetracyclines have been extensively used as adjunctives to conventional periodontal therapy. Emergence of resistant strains, however, has been reported. This study evaluated longitudinally the tetracycline resistance patterns of the subgingival microbiota of periodontitis subjects treated with systemic or local tetracycline therapy+scaling and root planing (SRP). METHODS: Thirty chronic periodontitis patients were randomly assigned to three groups: SRP+500 mg of systemic tetracycline twice/day for 14 days; SRP alone and SRP+tetracycline fibers (Actsite) at four selected sites for 10 days. Subgingival plaque samples were obtained from four sites with probing pocket depths (PPD)> or =6 mm in each patient at baseline, 1 week, 3, 6 and 12 months post-therapy. Samples were dispersed and diluted in pre-reduced anaerobically sterilized Ringer's solution, plated on Trypticase Soy Agar (TSA)+5% blood with or without 4 microg/ml of tetracycline and incubated anaerobically for 10 days. The percentage of resistant microorganisms were determined and the isolates identified by DNA probes and the checkerboard method. Significance of differences among and within groups over time was sought using the Kruskal-Wallis and Friedman tests, respectively. RESULTS: The percentage of resistant microorganisms increased significantly at 1 week in the tetracycline groups, but dropped to baseline levels over time. The SRP+Actsite group presented the lowest proportions of resistant species at 6 and 12 months. No significant changes were observed in the SRP group. The predominant tetracycline-resistant species included Streptococcus spp., Veillonela parvula, Peptostreptococcus micros, Prevotella intermedia, Gemella morbillorum and Actinobacillus actinomycetemcomitans (Aa). A high percentage of sites with resistant Aa, Porphyromonas gingivalis and Tanerella forsythensis was observed in all groups at baseline. However, T. forsythensis was not detected in any group and P. gingivalis was not present in the SRP+Actsite group at 1 year post-therapy. Aa was still frequently detected in all groups after therapy. However, the greatest reduction was observed in the SRP+Actsite group. CONCLUSION: Local or systemically administered tetracycline results in transitory selection of subgingival species intrinsically resistant to this drug. Although the percentage of sites harboring periodontal pathogens resistant to tetracycline were quite elevated in this population, both therapies were effective in reducing their prevalence over time.