2. Those cases that need recovery of proximal contact point because of food impact. 3. If the abutment of fixed bridge has caries, inlay can be designed to act as the retainer.
Simple surface inlay
Proximal surface inlay
MOD
MOD
3. According to the degree of defect：
Inlay： similar to filling material, within the scope of dental cusp.
2. Inlay is not suitable for those teeth with superficial defect.
3. Too severe dental defect without enough resistance form and retention.
4. Young patients who have strong desire for the outlook and long-term effect of prosthesis, inlay is not recommended to repair the defect of anterior teeth.
Onlay： severe defect, including one or more dental cusps. It covers the occlusal surface and has the function to recover the occlusal relation.
