Year : 2015

Volume : Volume 5

Issue : Issue 2

Address for correspondence :
Dr. M Bharathi
munagapatibharathi@gmail.com

Abstract

Aim: The present in vitro study was performed to evaluate the bond strength of acrylic resin teeth with and without retention grooves processed with three different heat cure acrylic  denture base materials and also to compare the bond strength of central and lateral incisors to denture base. Materials & Method: A total number of 180 Ivostar teeth comprising of 90 maxillary central incisors and 90 lateral incisors were selected to bonded to three different heat cure denture base resins namely Trevalon, Lucitone 199 high impact, and SR Triplex hot. These teeth were divided into three groups of 60 each. Group A, no surface modifications done. Group B, horizontal grooves 2mm deep and 2mm wide made on ridge lap. Group C, vertical grooves 2mm deep and 2mm wide cut into the ridge lap surfaces of the teeth.  A rectangular stainless steel mould of dimensions 8X10X20mm with a 450 taper to the long side was made and used to make the specimens. 10 samples of each of central and lateral incisors of each group were processed with three different heat cure acrylic resins. The specimens were placed on a universal testing machine- Instron. A point force was applied by a steel pin tip of 1.5mm diameter at an angle of 450 to the long axis of the tooth on the palatal surface, until fracture occurred at a crosshead speed of 0.5mm per minute. The fracture load was measured and recorded by a monitor in (Kg/cm2) for all specimens. Values were subjected to ANOVA, Tukey’s multiple post hoc procedures and T test. Results: Results revealed statistically significant difference in bond strengths between all the groups. The mean bond strength value with vertical grooves i.e. Group C was 28.05Kg/cm2 as compared to the horizontal grooves i.e. Group B (24.33Kg/cm2) and in control group A(20.26Kg/cm2) in central incisors. And in lateral incisors the mean bond strength values of group A, group B, Group C being 17.49, 21.79, 25.62Kg/cm2 respectively. Conclusion: Within the limitations of the study, the results showed that the bond strength was superior for the teeth with vertical grooves when compared to the horizontal grooves and which was further superior to teeth without any grooves on its ridge lap surface.

Keywords: Bond strength, retentive grooves, denture base resins, acrylic teeth.