DENTAL INLAY
DENTAL INLAY
• Inlay is a an indirect restoration which is fabricated in the lab and than cemented to the prepared cavity.
DIRECT VS INDIRECT RESTORATION
• In direct filling the material is taken in plastic state into the prepared cavity where it hardens.
• In indirect restoration the hardened filling is cemented into the prepared cavity
DIFFERENCE
AMALGAM RESTORATION
INLAY PREPARATION
Advantages of inlay
• Better physical properties• Clinical longevity• Easier to carve a large restoration to normal
occlusion and ideal contacts• Easy to make guide planes for removable
prosthesis• Easy to alter the occlusion• Aesthetic restoration
Disadvantages of inlay
• Costlier than direct restoration(Gold inlays cost 4-5 times that of a silver amalgam)
• Two visits for the patient• Microleakage, dependent on cement
Types
• Gold inlay• Porcelain inlay• Composite inlay
GOLD INLAY
• ADVANTAGESa) Co efficient of thermal expansion and wear
resistance similar to natural toothb) gold is relatively stable and inert in our bodies.c) Gold does not corrode & is highly polishabled) Strong even in thin section, can be burnished
for close adaptatione) Clinical longevity
GOLD INLAY
• DISADVANTAGESa) Costly(not in long run)b) Not aesthetic
Gold inlay
Gold inlay
• indicationsa) Failed amalgam restorationb) Large restorationc) Diastema closured) Rehabilitation casese) With removable prosthesis
Gold inlay
• Contra indicationsa) High cariesb) Young patientc) Esthetic concern of patientd) Small restorations
PORCELAIN INLAY
• Aesthetically excellent• More cutting for strength and translucency • Can damage opposing teeth if not properly
glazed
COMPOSITE INLAY
• Lab composite is more polymerized and has more filler content
• More strength• No polymerization shrinkage• Aesthetically excellent.
CONTRAINDICATIONS
• Cracked teeth (onlay)• Wide isthmus/deep pulpal (onlay)
Techniques
• Two techniques• Direct technique(difficult and tiring for both
the patient and the operator)• Indirect technique (easier for both and gives
better result)
DIRECT TECHNIQUE
• Where inlay wax is inserted into the prepared cavity, carved, contacts made and taken out of the cavity.
• the lab procedure than follow
Direct technique
INDIRECT TECHNIQUE
• Where an impression of the prepared cavity is taken and all other procedures are followed on the model in the lab.
Indirect technique
Steps
steps
steps
steps
steps
steps
steps
CEMENT LUTE
• Cement lute is the weakest part of inlay restoration
• Zinc phosphate cement and glass ionomer cements have been used for luting
• Presently non dissolving resin based luting agents are used but again the shrinkage
Controversies
• Inlays crack teeth ( careful selection)• Inlays are expensive ( are they?)• Inlays are not esthetic (careful cutting plus
tooth colored inlays)• Must place bevel at occlusal and proximal
PREPARATION
• Outline form• Resistance form• Retention form• Remove any undercuts• Finish the walls
Outline form
• A straight cut tapering fissure bur is used• Caries is removed from all around• Any existing restoration should be removed• Occlusally divergent walls (upto10 degrees)• Sharp internal angles
Outline form
• Occlusal dovetail• Butt joint at occlusal• The proximal flare must take the margin into
the respective embrasures clearing the adjacent teeth
Resistance form
• Minimum depth is 2mm all around• Proximal box should be at least 1-1.5mm
deeper• Flat pulpal floor
Resistance form
• If cusps are weak go for onlay preparation• Onlay-an inlay that covers the cusp of the tooth• Cuspal reduction-parallel to the slope• Reduction should not be less than 0.5mm
depending on the material, occlusion, working or non working cusp
• All the cusps should be out of occlusion in all excursions
Retention form
• Retention is based on nearly parallel walls• Up to 10 degree occlusal divergence is allowed
for ease of impression taking and placement of the final restoration
• There should be no undercut in the final preparation
Finish the walls
• A 60 degree gingival bevel is given by using a gingival margin trimmer
• It allows proper seal of the restoration in this area
• Paint the final outline to provide a more pleasing outline of the final restoration
I THANK YOU ALL
• All of the following are advantages of gold inlay except
a) The co efficient of thermal expansion and wear resistance is similar to natural tooth
b) Its relatively stable and inert in our bodies.c) Gold does not corrode d) A single visit procedure for the patient.