Oral Health and Dental Management

Development and verification of a reciprocating wear test method for dental materials

4^th Asia Pacific Congress & Expo on Dental and Oral Health

July 27-29, 2015 Brisbane, Australia

Kazi Rizwana Mehzabeen

Posters-Accepted Abstracts: Oral Health Dent Manag

Abstract:

Wear is one of the major concerns associated with the biomaterials used for dental restoration. Restorative materials with higher abrasiveness causes higher wear to the opposing teeth enamel. Hence, wear resistance is an important requirement for dental materials. Candidate materials need to be characterized prior to their applications. As clinical trials are long and expensive procedures, simulating wear tests are considered to be easier alternatives. Dental wear, however, is a complicated mechanism influenced by several physiologic factors. Few standards are followed to mimic dental wear mechanism in vitro. In this study, an easily accessible reciprocating wear test machine was developed. The machine featured multi-axial loading capacity with six test chambers. Variable temperature exposure of the oral environment was replicated with a thermal water-cycling system. Test parameters were ascertained from Ivoclar Wear Method aiming for 5 kg loading for 120,000 cycles at a frequency of 1.6 Hz. Minimum 0.7 mm sliding movement between specimen surfaces was required. Simultaneously, 320 cycles of 5�-55�C temperature variation was to be implemented with water irrigation. However, a continuous 37�C water circulation was also achievable with the designed system. Servo motors were used as force actuators. Heating and cooling units were equipped in thermal system. Retrieved human antagonists against ceramic restoratives were subjected to the wear experiments. Verification test results were analyzed along with test parameters. Loading velocity, contact time, and tolerance of applied forces were specified. Correlations between influencing factors and wear results were also investigated. Finally, reliability of the reciprocating wear test was addressed in terms of validation of test methods.