PRIMARY RESISTANCE FORM

Definition – Prevention of tooth or restoration fracture from occlusal forces.

1) Cavosurface angle ー butt joint ー 90 degree - Must be supported by sound dentine - must be located in an area free of occlusal stress
2) Flat Pulpal Floor
3) Internsl line angles ー rounded off

CLASS II
- Gingival beveling ーuse GMTー to give roll resistance
- Unsupported enamel rods(directed towards gingiva) are cut
- Gives strong filling

PRIMARY TOOTH
- enamel rods are occlusally directed
- ∴ no need gingival bevel for class II in primary