Journal of Dental Medicine

Background and Aims: Failure of bonding between artificial teeth and denture base material is a considerable problem for patients who wear dentures. Because of the cost of denture repair and the expensive price of foreign artificial teeth, this study was designed to compare the bond strength of composite and acrylic artificial teeth with heat-cured and auto-polymerized denture base resins.
Materials and Methods: In this experimental and in vitro study, two type of acrylic resin (heat-cured: Selectaplus H/ Trevalon, Dentsply and auto-polymerized: Rapid Repair, Dentsply) and four artificial teeth (acrylic Marjan New, composite Glamour teeth which both of them are Iranian) and Ivoclar acrylic and composite teeth were used. Therefore, 8 groups of 14 specimens each were evaluated. A shear bond strenghth test in a Universal Testing Machine was used. Data were analyzed using the 2-way ANOVA test.
Results: The bond strengths of acrylic teeth (Marjan New and Ivoclar) to heat-cured resin were similar (P=0.632) and statistically higher than those of composite teeth (Glamour and Ivoclar). Acrylic teeth (Marjan New and Ivoclar) and Glamour teeth had similar bond strength to auto-polymerized resin, which showed the highest bond strength values. Ivoclar composite teeth showed significantly the lowest bond strength (P<0.05). All acrylic teeth had the highest mean bond strengths to heat-cured resin which were significantly different from that of
auto-polymerized resin (P<0.05). However, the bond strengths of all composite teeth to both denture base resins were not significantly different (P>0.05).
Conclusion: Based on the results of this study, the type of denture base material and artificial tooth may influence the failure load.

  Background and Aims: Debonding of denture teeth from the denture base can be frustrating for both clinician as well as patient. The aim of this study was to determine the effect of different tooth preparations on the tensile bond strength of composite denture teeth to acrylic denture base material.

  Materials and Methods : In this experimental study, 108 anterior Glamour teeth were selected and divided into 9 groups, based on their preparation (physical: no physical change, glaze removal, creating two slots with 1.5 mm depth, creating a hole with 2.5mm depth, chemical: (without chemical materials, monomer, silane). Specimens were prepared and tested according to the methods of the International standards organization (ISO 20795-1). After attachment of teeth to acryl, the tensile bond stregth test was performed in a Universal Testing Machine (UTM) with a crosshead speed of 1mm/min and specimens were subjected to tensile force until failure. Data were analyzed with one-way ANOVA, Tukey HSD and Two-way ANOVA.

  Results: There were significant differences between the bond strength of tested groups (P=0.012). Based on Tukey test, there was a significant difference between monomer/without physical change group and without/without (P<0.001) and control group. No significant differences were found between the bond strengths of the other groups (P=0.17) . All specimens were debonded as cohesive failure.

  Conclusion: Application of monomer on the ridge lap surface led to improve the tensile bond strength between glamour composite denture teeth and Iranian acrylic resin, however physical changes were not effective. According to the cohesive failure of all the specimens, it can be concluded that the bond strength between this type of teeth and acrylic resin was stronger than the strength of teeth.