A NEW METHOD FOR ASSESSING MASTICATORY PERFORMANCE - A FEASIBILITY AND REPRODUCIBILITY STUDY

The aim of this study was to develop a method for assessing masticator y performance based on incorporation of a colour binder in a test mate rial with the presumption that the absorption of the colour is proport ional to the total surface area of the masticated material. This was t ested in vitro with erythrosin as the colour substance and Praestol 65 5BC as the colour binder incorporated into Satou's synthetic test mate rial (equal amount of carnauba wax and bariumsulphate). The authors fo und that the difference in spectrophotometrical absorbance between a s tandard erythrosin solution and the supernatant of the same solution i ncubated half an hour with artificially pulverized test material was a lmost Linearly correlated (r = 0.997) with the particle surface. This test material was then fabricated as small tablets and four adults che wed repeatedly five grams of these tablets to assess selectivity and r eproducibility of the method, A good selectivity was found in that wit hin the total range of the difference in absorbance (0.47-1.19) an int er-individual difference of more than 0.17 is significant on a 95% lev el with double experiments. There were no differences in the intra-ind ividual variation for double determinations between immediate repeat a nd 1 week interval performances but the reproducibility was disturbed when two subjects used their partial dentures.