Effect of light polimerization mode, time and mechanical and thermal load cycling on microleakage in adhesive restorations

Author(s)

Giulliana Panfiglio Soares

• Document type: Master's Dissertation
• Press: Campinas, SP.
• Institution: Universidade Estadual de Campinas (UNICAMP). Faculdade de Odontologia de Piracicaba
• Defense date: 2009-03-18

Examining board members

Flavio Henrique Baggio Aguiar; Paulo Henrique dos Santos; Luis Alexandre Maffei Sartini Paulillo

• Advisor: Flavio Henrique Baggio Aguiar; José Roberto Lovadino

Abstract

The maintenance of the bond integrity between tooth and resin systems is important for the clinical success of composite resin restorations. Thus, the aim of this "in vitro" study composed of two manuscripts, was to evaluate the microleakage of Class II dental restorations: 1) made with an adhesive system and a dental composite, varying light curing time and light curing modes of the adhesive system, submitted to the thermal and mechanical loading cycling; 2) made with an adhesive system and a dental composite, varying light curing time and light curing modes of the resin, submitted or not to the thermal and mechanical loading cycling. 270 bovine teeth were used for this study, and prepared Class II restorations varying the time and the light curing modes for the adhesive or composite resin. After that, the restorations were submitted to the microleakage test. Based on the results (Analysis of Variance (p=0,05) and Tukey test), within the experimental limits of this study, it can be concluded that: 1) the increase of the light curing time of an adhesive system did not show better results in the process of marginal microleakage, regardless the light curing modes used; 2) increasing the photoactivation time of the resin composite did not reduce the microleakage of the cervical interface of the restoration, regardless the light curing modes used; 3) use of light curing units with high irradiance did not show better results when compared with low irradiant energy, for the two first layers of resin composite; 4) the thermal and mechanical loading cycling increased the microleakage in groups LED 3a generation and Conventional (QTH) for the two first layers of resin composite. (AU)