Guidlines for practice
Carving the class II. cavity in a gypsum model.
1. Study class II. Preparation put on web. (is.muni. - preclinical dentistry II., lemurestudy
materials). Be familier with the design of the cavity.
2. You will carve the cavity in gypsum model. The steps will be:
1. Cavity outlines (the borders of the proximal box will be between proximal and
oral/buccal surface, be careful about the cavosurface angle).
2. Take an excavator and and excavate the cavity ­ see the model
3. Take a probe and create the box with undercuts.
4. Take a tooth brush and clean the tooth.
Preparation of the cavity in the resin models (we prepared in these models other cavities).
1. Take a fussure bur and prepare the cavity starting from the middle. The depht is appr.
2 ­ 3 mm occlusal. The proximal box is limited by: gingival border, axial wedges.The
gingival wall appr. 1 - 2 mm wide, prependicular to the axial wall. The depht of the
proximal box is appr. 2 mm. Istmus is appr  - 1/3 of intercuspal distance.
2. Prepare 1 cavity in the molar, 1 in the premolar.
3. Put the base mixed of zincphosphate cement ­ on both pulpal walls.
The MO cavity in the premolar and the molar ­ prepare these cavities.
Intercuspal distance Isthmus
DO cavity
in premolar
MOD
cavity in
premolar
Base should be put on pulpal walls only,
there must be space enough for the filling.