Conclusions: the variation of tooth position could affect the magnitude and direction of the main apical stress, in which the symmetry of the occlusion type was also involved.
The scroll wrap is the main movement part of compressor, only have the tooth, have no abrasion, thus the life is longer, so this is free maintenance compressor.
涡旋压缩机主要运动件涡盘只有啮合没有磨损，因而寿命更长，被誉为免维修压缩机。
3
Cement's main roles are to anchor the tooth in the gum and to help form new teeth.