Prosthetics II
Fixed dentures
Bridges
□ Abutments
Full metal crown Facet crown Metalo-ceramic crown
The axis must be parallel
Bridges
□ Pontic
Self cleaning bridge (sanitary bridge)
Contact pontic
Reduction - the area that is in contact with gingiva 1/3 of the occlusal size. Occlusal reduction depends og the magnitude from 10 - 30% reduction.
Preparation
Manufacturing procedure 1 .st phase in dental ofice
Taking impression - elastomers
n Antagonal impression )alginate
n Occlusal impresion - bite registration (intermaxillary relationship)
□ Provisional treatment
Manufacturing procedure 1 .st phase in dental lab
■ Plaster model- the dental arch is made of ultrahard gypsum, the base of a stone.
■ The model is divided after application of guide pins
n The antagonal model of stone
□ Mounting to the articulator (simulator)
Manufacturing procedure 1 .st phase in dental lab
□ The wax patern of the metal framework is manifactured
u Casted (the method of lost wax)
□ Adapted on the model
Manufacturing procedure 2.nd phase in dental ofice
□ The framework is tried out
□ The colour of veneering material is choosen
Manufacturing procedure 2.nd phase in dental lab
The veneering material is applied on the framework and polymerized ot burnt out (ceramics).
Manufacturing procedure 3.rd phase in dental ofice
■ The denture is tried out
□ Cemented
□ (zinkoxidphosphate cement, glasionomer or composite)
Fixed dentures
> Cemented (fixed) on/in pilots, abutment teeth.
> Inlays (inlays, onlays, overlays, partial crowns).
> Crowns
> Bridges
Inlays
□ Rigid fillings
□ Manufactured in a dental lab
■ Direct or indirect method
- Direct method rarely
- Indirect method most common
Inlay
□ Crown inlay
- a part of a clinical crown is replaced
i Root canal inlay
The inlay is cemented into the root canal and replaces a crown (abutment tooth -stump, snag)
Crown inlay
Material
> Composit
> Ceramics
> Metal Alloys
Crown inlays
Indikations
A big lost of dental tissues Big interdental spaces
Next to the crowns and bridges made of metal alloy
Crown inlays
Contra - indication
1. Too small - shallow (flat) cavities
2. High caries risk
3. Frontal area (metallic)
Onlay
Overlay
Partial crown
Crown
Retention of rigid fillings
Whitstand capability aaainst axial forces:
Geometry of the preparation Quality of the luting material
(facilitating shape)
Angle of convergence
>0°- maximum >6°- very good >15°- acceptable >20°- insuficient
Retaining areal
□ Surface of contact Rigid filling
Inlay or crown (internal, outer, combined)
Stability of rigid fillings
Whitstand capability against horizontal forces
Angle of convergence Axial length contact surface
Basic rules of cavity preparation
>Box
> No undercuts
> Light divergence of the walls (facilitating shape)
nlay of metal alloy
> Direct method
Direct modellation in the mouth Special wax - casting wax, (special polymers) Sprue pin Investment
Method of the lost wax
nlay of metal alloy
Direct method
> Central cavities (class I., classs V.)
> Root canal inlays
nlay of metal alloy
Indirect method
Taking of the impression Model
Modellation of the casting wax, (special polymers) Sprue pin Investment
Method of the lost wax
Aesthetic inlays - composite materials, ceramics
Special procedure
Indirect method always
Root canal inlay
Root canal filling
Direct method
Isolation
Modellation - casting wax, heated, flowing
Sprue pin Investment
Method of the lost wax (burntout in the special oven)
Indirect method
Impression
Model
Modellation - casting wax, heated, flowing
Sprue pin Investment
Method of the lost wax
(burntout in the special oven)
Indirect method
Impression
Model
Modellation - casting wax, heated, flowing
Sprue pin Investment
Method of the lost wax
(burntout in the special oven)