I am often asked how long each treatment is expected to last. Below is a list of the 10-year success rate for some common treatments according to numerous randomized clinical trial studies:
- Porcelain inlays/onlays: 91% – 94%.
- Not indicated when too much tooth structure is absent, at that point a full coverage crown is a better treatment option.
- Composite inlays/onlays: 90% – 94%.
- Not indicated when too much tooth structure is absent, at that point a full coverage crown is a better treatment option.
- Root canal therapy: 73% – 93%.
- The best results are in non-infected teeth without obstructions or abnormal anatomy (twisted or extra canals).
- Implants: 84% – 95%.
- Better results are seen in the mandible (lower arch).
- Crowns: 67% – 85.5%.
- Crowns are expected to last a minimum of 5 years, they can however last decades.
- Choice of crown material, existing tooth structure, and operator experience and technique affect the success rate of crowns.
Fillings: Composite resin fillings don’t last as long. You may need to replace them every five to seven years. They can be replaced only if there is enough tooth structure left to support a new filling.
Comparison of inlays vs. direct fillings: When an inlay is used, the tooth-to-restoration margin may be finished and polished to a very fine line of contact to minimize recurrent decay. In contrast, direct composite filling pastes shrink slightly during hardening. This can lead to shrinkage stress and rarely to marginal gaps and failure. Although improvements of the composite resins could be achieved, solid inlays don’t have to worry about this problem.
Another advantage of inlays over direct fillings is that there is almost no limitation on the choice of material. Inlays are superior in terms of resistance to occlusal forces, protection against recurrent decay, precision of fabrication, marginal integrity, proper contouring for gingival (tissue) health, and ease of cleansing offers.