Polarization of dental caries among individuals aged 15 to 18 years

OBJECTIVE: To evaluate the role of socioeconomic variables and self-perceived oral health in the polarization of caries among adolescents in Santa Bárbara D'Oeste, Brazil. MATERIAL AND METHODS: Cross-sectional study. Sampling was randomized and sample size was defined according to WHO criteria. Two hundred and seventy seven adolescents (15 to 18 year-old) were examined by five trained examiners that assessed DMFT index according to WHO criteria. Self-perceived oral health, access to dental services and socio-demographic variables were self-reported. Student's t tests, chi-square tests, and multivariate logistic regression (with significant caries index (SiC) as the outcome), were performed. RESULTS: Mean DMFT was 5.48 (±4.22) and the proportion of "caries free" subjects was 15.5%. Mean DMFT (9.71±2.85) and mean D (1.67±2.18) of SiC positive subjects were significantly higher than mean DMFT (2.88±2.17) and mean D (0.45±0.87) of SiC negative subjects (

Influence of the Culture Medium in Dose-Response Effect of the Chlorhexidine on Streptococcus mutans

The aim of this study was to evaluate the influence of culture medium on dose-response effect of chlorhexidine (CHX) on Streptococcus mutans UA159 biofilm and validate the use of the cation-adjusted-Müller-Hinton broth (MH) for the evaluation of antibacterial activity. Ultrafiltered Tryptone-Yeast Extract Broth (UTYEB) was compared against MH and MH with blood supplementation (MHS). For each medium, six groups (n=4) were assessed: two negative control groups (baseline 48 and 120 h) and four experimental groups (0.0001, 0.001, 0.012, and 0.12% CHX). S. mutans biofilm grew on glass slides of each media containing 1% sucrose. After 48 h of growth, biofilms of baseline 48 h were collected and the other groups were treated for 1 min, twice a day, for 3 days, with their respective treatments. The media were changed daily and pH was measured. After 120 h, biofilms were collected and dry weight and viable microorganisms were determined. Results showed CHX dose-response effect being observed in all media for all the variables. However, MH and MHS showed higher sensitivity than UTYEB (p<0.05). We can conclude that the culture medium does influence dose-response effect of CHX on Streptococcus mutans biofilm and that MH can be used for antibacterial activity

S. mutans biofilm model to evaluate antimicrobial substances and enamel demineralization

The aim of this study was to validate a model of S. mutans biofilm formation, which simulated 'feast-famine' episodes of exposure to sucrose that occur in the oral cavity, showed dose-response susceptibility to antimicrobials and allowed the evaluation of substances with anticaries potential. S. mutans UA159 biofilms were grown for 5 days on bovine enamel slabs at 37°C, 10% CO2. To validate the model, the biofilms were treated 2x/day with chlorhexidine digluconate (CHX) at 0.012, 0.024 and 0.12% (concentration with recognized anti-plaque effect) and 0.05% NaF (concentration with recognized anti-caries effect). CHX showed dose-response effect decreasing biomass, bacterial viability and enamel demineralization (p < 0.05). Whereas, 0.05% NaF did not show antimicrobial effect but had similar effect to that of 0.12% CHX decreasing enamel demineralization (p < 0.05). The model developed has potential to evaluate the effect of substances on biofilm growth and on enamel demineralization

SOLUBILIDAD Y DUREZA SUPERFICIAL DE CERÁMICAS ODONTOLÓGICAS DESPUÉS DE SER EXPUESTAS A FLUIDO GÁSTRICO ARTIFICIAL. ESTUDIO IN VITRO

Enfermedades como reflujo gastroesof&aacute;gico y bulimia, provocan alteraciones &aacute;cidas en la cavidad bucal que pueden causar erosi&oacute;n dental. El efecto de este medio &aacute;cido sobre materiales restauradores y posibles cambios en sus propiedades son poco relatado en la literatura. De esta forma, el objetivo de este trabajo fue evaluar la solubilidad y la microdureza de cer&aacute;micas feldesp&aacute;ticas expuestas in vitro a fluido g&aacute;strico simulado sin enzimas (pH 1,2). Fueron confeccionados 100 discos, de 8mm de di&aacute;metro y 2mm de altura, con las siguientes cer&acirc;micas: Vitadur Alfa (I), Vita Omega 900 (II) Finesse All-Ceramic (III), IPS dSign (IV) y Carmen (V). Estos fueron divididos en tres grandes grupos seg&uacute;n la exposici&oacute;n al fluido g&aacute;strico: (A) sin exposici&oacute;n, (B) 24 horas de exposici&oacute;n y (C) 7 d&iacute;as de exposici&oacute;n. La solubilidad fue evaluada por medio del pesaje en balanza digital (Metler Toledo), calcul&aacute;ndose la cantidad de p&eacute;rdida de masa (MP). El an&aacute;lisis de microdureza Vickers (MD) fu&eacute; realizado utilizando un microdur&oacute;metro FM-700 (Future Tech). Los resultados obtenidos mostraron valores de p&eacute;rdida de masa (%) de B, comparado con A, de: 0,1280(I), 0,2143(II), 0,0485(III), 0,1377(IV), 0,0824(V); y para C de: 0,1182(I), 0,2305(II), 0,0773(III), 0,1653(IV), 0,3256(V). Se observaron valores de dureza superficial para A de: 527,53(I), 531,67(II), 519,85(III), 544,72(IV), 523,72(V); para B de: 505,38(I), 529,63(II), 478,60(III), 514,91(IV); 504,97; y C de: 484,96(I), 495,61(II), 493,5(III), 482,76(IV), 488,22(V). El an&aacute;lisis estad&iacute;stico con el test de ANOVA (p&lt;0,05), mostr&oacute; influencia del fluido g&aacute;strico tanto en la p&eacute;rdida de masa como en la solubilidad de las cer&aacute;micas evaluadas