Shear Bond Strength of Acrylic Teeth to Heat-curing Denture Base Resin under Different Disinfectant Methods Resistencia al Cizallamiento de Dientes Acrílicos en Bases Protésicas de Resina con Curado Térmico bajo Diferentes Métodos de Desinfección

The aim of this study was to evaluate the shear bond strength between acrylic teeth and heat-activated acrylic denture base resin using five different disinfectants solutions after simple immersion or under ultrasonic cleaner action. A total of 144 acrylic denture resin specimens were produced with both types of acrylic denture tooth (Bioluxand Trilux¤). The specimens were randomly divided into subgroups according to the disinfection procedure used (immersion in Listerine¤, Cepacol¤, Periogard¤, Riozyme IIand Cloro Rio¤ 1%, and/or ultrasonic cleaning action). The shear bond strength between acrylic teeth and denture base was assessed using a universal testing machine and the data obtained were analyzed by means of ANOVA followed by Fisher's LSD Multiple-Comparison test. The two layers teeth presented a bond strength average of 3.43 MPa while the three layer ones had an average of 3.02 MPa. The association of ultrasonic cleaner and the disinfectant solutions studied did not affect negatively the teeth bond resistance to the denture base. The three layer acrylic teeth had a lower shear bond strength compared to those with double pressing when immersed in disinfection solutions, regardless of the ultrasonic cleaner use. ˚