ABSTRACT Introduction: Primary health care solves most of the health problems of the population, provides primary access to the service, ensures the continuity and comprehensiveness of health care, and coordinates its different forms. Objective: Evaluate the relationship between primary health care quality and dental caries in preschoolers. Methods: A cross-sectional descriptive study was conducted of a sample of 515 preschoolers. Participant schools were selected by stratified random sampling, followed by simple random sampling for the selection of participant children. Oral examination was performed to evaluate dental caries, and parents / guardians were given a questionnaire about the quality of the primary services attended by their children. Data were estimated with the chi-squared test, the Wilcoxon test and Spearman's coefficient (95% confidence). Results: A relationship was found between primary health care quality and the ceod index of preschoolers (ρ = -0.19; p < 0.05). Significant differences were observed in the prevalence of dental caries when quality services (ceod = 0.50) were compared with the low quality group (ceod = 1.13). Quality was also associated to the service mode (p < 0.001). Private services and the family health strategy obtained higher quality scores (55.31% and 69.48%, respectively). Conclusions: Primary health care quality is closely related to oral health, in such a way that when the quality of primary health care services is not good, a higher dental caries rate is observed among preschoolers.

RESUMEN Introducción: La atención primaria de salud aporta la resolución de la mayoría de los problemas de salud de la población, proporciona el acceso primario al servicio, la continuidad e integralidad de la atención y la coordinación de los cuidados. Objetivo: Evaluar la relación entre la calidad de los cuidados primarios y la caries dental en preescolares. Métodos: Se realizó un estudio descriptivo de corte transversal en una muestra de 515 preescolares. La selección de las escuelas tuvo lugar a partir de un muestreo aleatorio estratificado, seguido por muestreo aleatorio simple para la selección de los participantes. Se realizó un examen bucal para evaluar caries dental y se aplicó a los padres/responsables un cuestionario de calidad de los servicios primarios utilizados por los niños. Se emplearon chi cuadrado, Wilcoxon y el coeficiente de Spearman (95 % de confianza) para el cálculo de los datos. Resultados: La calidad de la atención primaria tuvo relación con el índice ceod de preescolares (ρ = -0,19; p < 0,05). Se observó diferencias significativas entre la prevalencia de caries dental cuando comparados servicios de calidad (ceod = 0,50) con el grupo baja calidad (ceod = 1,13). También, la calidad fue asociada con la modalidad del servicio (p < 0,001), obteniéndose en los servicios privado y la estrategia de salud de la familia puntajes mayores (55,31 % y 69,48 % de calidad, respectivamente). Conclusiones: La calidad de la atención primaria está estrechamente relacionada con salud bucal, de esta forma, cuando la calidad de los servicios de atención primaria no es buena, repercute en un mayor índice de caries dental en los preescolares.

RESUMO Este estudo teve por objetivo avaliar a influência do pré-aquecimento de compósitos bulk-fill, em relação a resistência à flexão, módulo de elasticidade e resistência coesiva. Cinco compósitos foram testados: Tetric N-Ceram Bulk-fill (TBF), X-tra fill (XTF), Filtek Bulk-fill (FBF), Aura Bulk-fill (ABF) e Filtek Z250 (FZ, controle). As amostras foram condicionadas em 37ºC por 24 horas antes de serem testadas. Os resultados foram analisados estatisticamente por ANOVA e teste de Tukey. Os compósitos FBF, XTF E FZ apresentaram as maiores resistências coesivas, e o pré-aquecimento influenciou positivamente esta propriedade. Os materiais XTF e FBF sem pré-aquecimento apresentaram os maiores valores de resistência à flexão e de módulo de elasticidade. Para estas propriedades, o pré-aquecimento causou redução nos compósitos XBF, FBF e ABF, não teve efeito em TBF e causou aumento em FZ. O pré-aquecimento influenciou positivamente a resistência coesiva dos materiais estudados, melhorando o desempenho de todas os materiais do tipo bulk-fill. A Tetric N-Ceram Bulk Fill/Ivoclar não obteve variação de módulo de elasticidade e resistência flexural quando pré-aquecida, tendo os demais compósitos do tipo bulk-fill apresentado resultados inferiores quanto a essas duas propriedades após o aquecimento.

ABSTRACT The purpose of this study was to evaluate the influence of pre-heating of bulk-fill composites on flexural strength, modulus of elasticity and cohesive strength. Five composites were tested: Tetric N-Ceram Bulk-fill (TBF). X-tra Fill (XTF), Filtek Bulk-fill (FBF), Aura Bulk-fill (ABF) and Filtek Z250 (FZ, control). The samples were conditioned at 37ºC for 24 hours before being tested. Results were statistically analyzed by ANOVA and Tukey test. FBF, XTF and FZ composites had the highest cohesive strengths, and preheating positively influenced this property. XTF and FBF materials without preheating showed the highest values of flexural strength and modulus of elasticity. For these properties, preheating caused a reduction in XBF, FBF and ABF resins, had no effect on TBF resin and caused an increase in FZ resin. The preheating positively influenced the cohesive strength of the studied materials, improving the performance of all bulk-fill resins. Tetric N-Ceram Bulk Fill/ Ivoclar did not show changes on modulus of elasticity and flexural strength when preheated, while the other bulk-fill composites presented lower results for these two properties after heating.

O objetivo deste estudo foi avaliar a influência do material de inclusão e da simulação de ligamento periodontal na resistência à fratura de dentes bovinos. Oitenta incisivos bovinos foram divididos em 8 grupos (n = 10) e, então, incluídos em cilindros com dois materiais, resina acrílica ou resina de poliestireno, usando-se quatro tipos de simulação do ligamento periodontal: 1 - ausência do ligamento; 2 - material de moldagem à base de poliéter; 3 - material de moldagem à base de polissulfeto; e 4 - material elastomérico à base de poliuretano. As amostras foram armazenadas em 100% de umidade a 37°C por 24 horas e então submetidas a carregamento tangencial na superfície palatina com velocidade de 0,5 mm/minuto até a fratura. Os padrões de fratura foram analisados de acordo com: 1 - fraturas coronais; 2 - fratura da junção esmalte-cemento; 3 - fratura parcial da raiz; 4 - fratura radicular total. A análise estatística empregou análise de variância fatorial e teste de Tukey (p < 0,05). Os resultados mostram que o método de inclusão e a simulação do ligamento periodontal tiveram efeito significativo na resistência à fratura. O ligamento periodontal artificial modificou os padrões de fratura.

The aim of this study was to evaluate the influence of the embedment material and periodontal ligament simulation on fracture resistance of bovine teeth. Eighty bovine incisor teeth were randomized into 8 groups (n = 10), embedded in acrylic or polystyrene resin using 4 types of periodontal ligament simulation: 1 - absence of the ligament; 2 - polyether impression material; 3 - polysulfide impression material; 4 - polyurethane elastomeric material. The specimens were stored at 37°C and 100% humidity for 24 hours. Specimens were submitted to tangential load on the palatal surface at 0.5 mm/minute crosshead speed until fracture. The fracture modes were analyzed as follows: 1 - coronal fracture; 2 - cemento-enamel junction fracture; 3 - partial root fracture; 4 - total root fracture. Statistical analyses by two-way ANOVA and Tukey's test were applied (p < 0.05). The results showed that root embedment method and periodontal ligament simulation have a significant effect on fracture resistance. Artificial periodontal ligament modified the fracture modes.