RESUMO
Este trabalho avaliou a influência do tratamento de superfície na dentina radicular na resistência de união com pinos de fibra de vidro e cimento resinoso autoadesivo. Coletou-se 120 dentes incisivos inferiores bovinos dos quais 30 foram selecionados e tiveram suas coroas cortadas, permanecendo o remanescente radicular de 16 mm. Foi realizado o tratamento endodôntico e preparo intracanal para o pino, com profundidade de 8 mm para cimentação com cimento resinoso autoadesivo. As amostras foram divididas, randomicamente, em três grupos, segundo o tipo de tratamento de superfície, para limpeza intracanal após o preparo para cimentação: Grupo I - água destilada; Grupo II - EDTA 17% e Grupo III - clorexidina 0,12%. Os corpos de prova formados pelo conjunto dente-pino foram cortados no terço cervical, médio e apical, obtendo espécimes com 2,0 mm de espessura. Os espécimes foram levados à máquina de ensaios universal com velocidade de 0,5 mm/min para teste de resistência ao cisalhamento æpush-outÆ. A análise dos resultados foi feita com o teste ANOVA e Teste de Tukey (p<0,05). Os efeitos da água destilada, clorexidina 0,12% e EDTA 17% foram diferentes no tratamento superficial da dentina radicular, havendo diferença na resistência de união entre pinos de fibra de vidro e cimento resinoso autoadesivo nos terços cervical (p<0,013) e médio (p<0,026), sendo que o grupo da clorexidina 0,12% teve os melhores resultados. Isto permite sugerir novo protocolo de cimentação, com ação desinfetante (clorexidina), sem comprometer a resistência de união...
This study has evaluated the influence of different root canal dentin pre-treatments on the bond strength of radicular glass fiber posts. One hundred twenty bovine lower incisors were collecte. Thirty of them were selected and had their roots sectioned 16 mm from their apices. , Endodontic treatment and post space preparation to 8 mm deep were performed for cementation with self-adhesive resin cement. Samples were randomly divided into three according to surface treatments: Group I - irrigation with distilled water; Group II - irrigation with 17% EDTA; and Group III - irrigation with 0.12% chlorhexidine. Roots were then cut into 3 discs of 2 mm thick each and separated according to the region into cervical, medial and apical discs. A push-out bond strength test was performed by a universal testing machine at a crosshead speed of 0.5 mm/min. Data were analyzed with one way analysis of variance (ANOVA) and Tuckey test (p<0.05). Mean bond strength values showed significant difference between the groups in the cervical region (p<0.013) and medial region (p<0.026), that suggest a new bond protocol with disinfectant effect using 0.12% chlorhexidine without negative impact on bond strength...
Assuntos
Bovinos , Cavidade Pulpar , Cimentos Dentários/química , Dentina , Incisivo/anatomia & histologia , Materiais Restauradores do Canal Radicular/química , Resistência à Tração , Análise de Variância , Clorexidina/química , Hidróxido de Sódio/químicaRESUMO
PURPOSE: The purpose of this study was to evaluate the effect of simulated disinfections (2% glutaraldehyde, 1% sodium hypochlorite, and microwave energy) on the surface hardness of Trilux, Biocler, Biotone, New Ace, and Magister commercial artificial teeth. MATERIALS AND METHODS: Specimens (n = 10) were made with the teeth included individually in circular blocks of acrylic resin, leaving the labial surface exposed. Cycles of simulated chemical disinfection were accomplished with the specimens immersed in the solutions at room temperature for 10 minutes, followed by tap water washing for 30 seconds and storage in distilled water at room temperature for 7 days until the next disinfection. Simulated disinfection by microwave energy was carried out in a domestic oven with 1300 W at a potency of 50% for 3 minutes with the specimens individually immersed in 150 ml of distilled water. Control (no disinfection) and the experimental groups (first and third disinfection cycles) were submitted to Knoop hardness measurements with indentations at the center of the labial tooth surface. Data were submitted to repeated measure two-way ANOVA and Tukey's test (α = 0.05). RESULTS: Biocler, Magister, and Trilux showed lower surface microhardness when submitted to microwave. Lower microhardness for Biotone was promoted by hypochlorite, while no significant difference was shown for New Ace. The third disinfection cycle significantly decreased the tooth surface hardness only for microwave. CONCLUSIONS: Different disinfection methods promoted different effects on the microhardness of different types of artificial teeth. Surface microhardness of the teeth was less affected by the simulated chemical disinfections when compared to microwaved specimens.