Sequences of operation
Fixed dentures:
Full crown
Made of metal alloy (gold or chromcobalt)
1. Phase in dental office
Preparation –
Reduction 1 mm around, occlusaly 1, 5 mm
Preparation border. slight chamfer
Taking impression
Elastomeric impression materials
Polysulfid, silicon, elastomers.:
Retraction cord around the tooth
Dual viscosity technique or single viscosity technique.
Dual viscosity technique – double impression
Simultaneous dual viscosity technique
Antagonal impression
Alginate
Occlusal registration (wax, elastomeric materials)
1. Phase in dental lab.
Making the cast (model) of gypsum.
There are three types of base raw materials derived from partial dehydratation of gypsum
rock depending on on the nature:
Plasters – fluffy, porous, least dense.
Hydrocal – hihger density, more crystalline
Densite – densest of the raw material.
Plasters----- Model plaster, lab plaster
Hydrocal----dental stone
Densite ------High strength dental stone
High strength dental stone is used for fixed dentures.
Wax pattern
Lost wax method. – investment and casting, finishing.
2. Phase in dental office
Try and cementation.
Sequences of operation
Fixed dentures:
Metal ceramic crown
Made of matal alloy ( usu chromcobalt) and ceramics which covers the metal framework
1. Phase in dental office
Preparation –
Reduction 1 mm around, occlusaly 1, 5 mm
Preparation border. slight chamfer
Taking impression
Elastomeric impression materials
Polysulfid, silicon, elastomers.:
Retraction cord around the tooth
Dual viscosity technique or single viscosity technique.
Dual viscosity technique – double impression
Simultaneous dual viscosity technique
Antagonal impression
Alginate
Occlusal registration (wax, elastomeric materials)
2. Phase in dental lab.
Making the cast (model) of gypsum.
There are three types of base raw materials derived from partial dehydratation of gypsum
rock depending on on the nature:
Plasters – fluffy, porous, least dense.
Hydrocal – hihger density, more crystalline
Densite – densest of the raw material.
Plasters----- Model plaster, lab plaster
Hydrocal----dental stone
Densite ------High strength dental stone
High strength dental stone is used for fixed dentures.
Wax pattern
Lost wax method. – investment and casting, finishing of the framework
3. Phase in dental office
Try and colour choice
4. making of ceramic
special procedure – firing in sesial oven in several phases.