Relationship between fluoride exposure and count of Streptococcus mutans in supragingival biofilm of mexican scholar children.

BACKGROUND/PURPOSE: The use of fluoride is known to reduce the risk of dental caries. There is limited information on the relationship between Streptococcus mutans (S. mutans) and fluoride exposure. This study investigated the association between the count of S. mutans on supragingival biofilm and fluoride exposure of scholar children. MATERIALS AND METHODS: In this cross-sectional study, 56 children from 9 to 11 years of age were selected. Fluoride concentration in drinking water, urine and saliva of each participant were assessed. The count of S. mutans was estimated by calculating the DNA copy number through a quantitative real time polymerase chain reaction (qPCR) assay. Also, sociodemographic data, oral and general health information and variables related to caries risk were evaluated. A stepwise multiple linear regression was performed in all caries related predictor variables with the count of S. mutans as the dependent variable. RESULTS: The multiple linear regression analysis showed that the concentration of fluoride in saliva (ß = -3.029, p < 0.001) and urine (ß = -2.057, p = 0.017), time of last visit to the dentist (ß = 1.968, p = 0.001), plaque index (ß = 1.637, p = 0.006) and number of surfaces with codes 3-6 (D3-6MFS) of ICDAS II criteria (ß = 0.283, p = 0.076) were significantly associated with the count of S. mutans (Adjusted R square = 0.427, p < 0.001). CONCLUSION: Fluoride levels in urine and saliva were negatively associated with the count of S. mutans in supragingival biofilm. Plaque index, D3-6MFS and time of last visit to the dentist showed a positive association.

Comparative Evaluation of Bond Strength of Self-Etching and Total Etch Dental Adhesive Systems to Dentin of Deciduous and Permanent Teeth / Evaluación Comparativa de la Fuerza de Unión de los Sistemas de Adhesivo Dental Autograbado y Grabado Total para la Dentina de Dientes Deciduos y Permanentes

ABSTRACT: The aim of this study was to analyze the bond strength of total-etch and self-etch adhesive systems to dentin of primary and permanent teeth. Methods: Thirty sound naturally exfoliated primary molars deciduous teeth (DT) and thirty sound permanent bicuspids permanent teeth (PT) were randomly divided into six groups (n=10 per group) according to two commercial adhesive systems: Adper Single Bond 2; 3M ESPE (Total-etch) and Adper Easy Bond; 3M ESPE (selfetch and total-etch). Specimens submitted to cyclic loading in a universal Instron testing machine. Bond strength values (MPa) were analyzed by ANOVA test and Duncan post hoc test (a=0.05). Results: Mean values were higher in PT compared to DT. In deciduous teeth, no significantly differences observed. Total etch AdperTM Single Bond 2 showed significantly higher bond strength than self-etch AdperTM with additional acid etching in PT (p=0.031). Conclusion: Our findings suggest that the highest bond strength was found in dentin tissue of PT with total etch AdperTM employing the adhesive the Single Bond 2 of one step self-etch.

RESUMEN: El objetivo de este estudio fue analizar la fuerza de unión de los sistemas adhesivos de grabado total y autograbado a la dentina de los dientes primarios y permanentes. Métodos: treinta sonidos exfoliaron naturalmente los molares primarios dientes caducifolios (DT) y treinta sonidos. Los dientes permanentes de los premolares permanentes (PT) se dividieron aleatoriamente en seis grupos (n = 10 por grupo) de acuerdo con dos sistemas adhesivos comerciales: Adper Single Bond 2; 3M ESPE (Grabado total) y Adper Easy Bond; 3M ESPE (autograbado y grabado total). Muestras sometidas a carga cíclica en una máquina universal de pruebas Instron. Los valores de resistencia de la unión (MPa) se analizaron mediante la prueba ANOVA y la prueba post hoc de Duncan (a = 0.05). Resultados: Los valores medios fueron mayores en PT en comparación con DT. En dientes deciduos, no se observaron diferencias significativas. Total etch AdperTM Single Bond 2 mostró una fuerza de unión significativamente mayor que la autograbado AdperTM con grabado ácido adicional en PT (p = 0.031). Conclusión: Nuestros hallazgos sugieren que la mayor fuerza de unión se encontró en el tejido de dentina de PT con grabado total AdperTM empleando el adhesivo Single Bond 2 de autograbado de un solo paso.