Effect of ultrasound on bond strength and penetration of resin and ionomeric cements used for fiberglass post cementation

• Ano de defesa: 2017
• Autor(a) principal: Mamani, Mauro Elisban Diaz
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: eng
• Instituição de defesa: Biblioteca Digitais de Teses e Dissertações da USP
• Palavras-chave em Português: Cimentos resinosos; Confocal microscopy; Fiberglass post; Microscopia confocal; Pino de fibra de vidro; Push out; Resin cements; Ultrasound; Ultrassom
• Link de acesso: http://www.teses.usp.br/teses/disponiveis/25/25148/tde-23052018-143746/

Objective: The objective of this study was to evaluate the bond strength of fiberglass posts (Exacto N° 2 ®) cemented with resin cement (RC) and resin modified glass ionomer cement (RMGI), with and without ultrasonic activation in the root canal of bovine teeth. The penetration of the cements into dentine tubules was also assessed. Methods: Forty bovine incisors were selected and endodontically treated, and then divided into 4 groups (n = 10). Fiberglass posts were cemented with RC and RMGI and activated with an ultrasound insert in 2 groups; the other two groups received no ultrasonic activation. After 1 week of cementation, the roots were sectioned into 9 slices of approximately 1,5 mm each. Confocal microscopy and push-out test were performed, and all specimens were subjected to 200x magnification optical microscopy for mode of failure evaluation. Statistical analysis was done with three-way ANOVA, followed by the Fishers test ( = 0.05). Results: There was no difference among the root thirds in the RMGI group while a difference was found among the thirds in the RC group. In addition, the bond strength of the RC group was higher than the RMGI group, in all thirds. The RC also showed a greater penetration than the RMGI, in all thirds, with and without activation. The ultrasound activation caused a greater penetration only in the cervical and middle thirds in the RMGI group, and in the middle third of the RC group. Conclusion: The RC presented higher bond strength and penetration compared to the RMGI and ultrasonic activation improved the penetration of the RMGI cement in the middle and cervical root thirds and of the RC in the middle root third. A significant correlation between bond strength and penetration was verified in all groups. Clinical relevance: Ultrasound can promote a better penetration of resin cements used in fiberglass post cementation, reaching the most difficult anatomical areas in the root canal.