COMPARATIVE EVALUATION OF SHEAR AND TENSILE BOND STRENGTH OF CROSS LINKED ACRYLIC DENTURE TEETH TO DENTURE BASE RESINS CURED BY HEAT AND MICROWAVE POLYMERISATION TECHNIQUES- AN IN VITRO STUDY
Abstract
ABSTRACT: Background :Debonding of denture teeth from denture base resins present a common clinical problem. Secondly the processing of heat cure denture base resins is time consuming and cumbersome procedure.
Purpose- The aim of the study is to compare and evaluate the shear bond strength and tensile bond strength of cross linked acrylic denture teeth to denture base resin cured by heat and microwave polymerization techniques.
Materials & Methods – A total number of 40 cross linked maxillary central incisors & 40 mandibular molars (Acryrock Ruthinium, badiapolesine - ITALY) of same mould size with regard to size and shape were selected to be bonded to Heat cured resin (Luciton199, Dentsply) by conventional heat cure polymerization method and microwave polymerization method.
The samples were divided into 4 groups:
Group 1 – Specimen for shear bond strength cured by conventional heat cure polymerization method.
Group 2 - Specimen for shear bond strength cured by microwave polymerization method.
Group 3 – Specimen for tensile bond strength cured by conventional heat cure polymerization method.
Group 4 - Specimen for tensile bond strength cured by microwave polymerization method.
Each group consisted of 20 specimens. A total of 80 specimens were prepared.
Group 1 and 2 were tested for shear bond strength and group 3 and group 4 were tested for tensile bond strength on universal testing machine.
Results: The mean tensile bond strength for the heat polymerized specimens was found to be 19.09 Mpa.
2) The mean tensile bond strength for the microwave polymerized specimens was found to be 12.41Mpa.
3) The mean shear bond strength for heat polymerized specimens was found to be 8.66 Mpa.
4) The mean shear bond strength for the microwave polymerized specimens was found to be 10.26Mpa.
Conclusion : The tensile bond strength specimens showed statistically significant differences in the bond strength. The tensile bond strength of the heat polymerized specimens was found to be higher. The shear bond strength specimens did not showed statistically significant difference in the shear bond strength. The shear bond strength of the microwave polymerized specimens was found to be equivalent to that of heat polymerized specimens.
