Development of Testing Method for Dental Materials - Part 1 Failure Evaluation of High-strength Resin Denture Teeth

摘要

The purpose of this investigation is to develop testing methods to evaluate dental materials that are exposed in mouth to the combined attack of microbe corrosion and mechanical forces that are caused through the collision of teeth. Stresses which are originated on teeth while chewing soft or hard foods were determined by use of a load sensor (Tekscan Inc.) to obtain the extent of the maximum load, loading speed and the contact duration, which were ranged from 40-130 N, 0.3-0.7 kN/s, 420-500 ms respectively. As to dental resin materials, a whole piece of false tooth was used as test specimen because it is a composite that consists of three different types of resin. Repeated collision test revealed firstly that the decrease in teeth height is caused not through wear but through the deformation of whole tooth piece, secondly that the deformation behavior changes its manner at the collision frequency of about 50000 times, and thirdly that the repeated collision test with low load reveals a characteristic behavior of material which is quite different from that of a single time loading test with a much higher load. Basing on the test results, a new test method for resin teeth in mouth environment was proposed.