The purpose of this study was to evaluate effects of dental cutting instruments and coolants to temperature changes of pulp chamber and to cutting weights.
To evaluate effects of dental cutting instruments, the experimental groups were devided into 16. Four restorative materials (gold, base metal, resin, porcelain) were grinding with 4 cutting instruments(high speed diamond point, high speed fissure bur, low speed stone point, low speed rubber point).
To evaluate effects of coolants, 16 groups were devided into 3 subgroups
Group A : no use of coolant
Group B : use of air coolant
Group C : use of water-air spray coolant
The results were as follows :
1. In kinds of coolants, temperature changes were shown in such order as group A, group B, group C. There was statistically significant difference between each group(p<0.05). Cutting weights were shown in such order as group C, group B, group A. There was statically significant difference between group C, B and A(p<0.05).
2. In kinds of cutting instruments, temperature change of diamond point as highest and temperature changes of high speed groups were higher than those of low speed groups. Cutting weights of fissure bur was highest and cutting weights of high speed groups were higher than those of low speed groups.
3. In kinds of materials of specimens, temperature change of base metal was highest and there were statistically significant difference between gold, base metal and resin, porcelain(p<0.05). Cutting weight of gold and base metal were higher than those of resin and porcelain.
4. The surface of specimen of group C, specially in use of high speed cutting instrument, showed less small particles than group A, B in SEM evaluation.
|