TENSILE BOND STRENGTH BETWEEN SELF-CURED ACRYLIC RESIN AND VARIOUS ACRYLIC DENTURE TEETH TREATED WITH METHYL FORMATE-METHYL ACETATE SOLUTION

This study evaluated the use of methyl formate-methyl acetate (MF-MA) solution on the tensile bond strength between acrylic denture teeth and self-cured acrylic resin. Maxillary central incisor acrylic denture teeth (Yamahachi New Ace: YA, Cosmo HXL: CH, Trubyte Bioform IPN: TB) were ground on their ridge lap surfaces. This study was divided into two parts. First part, the teeth of each brand were divided into seven groups (n=10) (no treatment, MF-MA for 15, 30, 60, 120, 180 s, and MMA for 180 s. Second part, the teeth of each brand were divided into three groups (n=10) with thermocycling (no treatment, MMA for 180 s, and MF-MA for the optimum time determined in the first part). After their respective treatments, self-cured acrylic resin (Unifast Trad) was applied. The results were analyzed using one-way analysis of variance (ANOVA). The results of the first part indicated that the surface treatment groups had significantly higher tensile bond strengths compared with no treatment group (p<0.05) within the same brand, except for TB MF-MA 15 s group (p>0.05). There were no significant differences in tensile bond strength between MMA 180 s, MF-MA 15 and 30 s groups (p>0.05). In second part, there were no significant differences between the thermocycling and non-thermocycling control groups of all brands (p>0.05). However, significant differences were present between some treatment groups (p<0.05). The results indicated that application of MF-MA for 15 s or 30 s can be an alternative chemical surface treatment for rebonding acrylic denture teeth with self-cured acrylic resin. Although thermocycling reduced bond strength of treatment groups, it did not in the control groups.