Indirect ceramic overlay restorations as a minimally invasive alternative for posterior rehabilitation

Abstract

Introduction: Full coverage crowns are still the most common procedure. Indirect partial overlay restorations have been suggested as a minimally invasive alternative, preserving more healthy tooth structure while providing cusp protection. Objective: To analyze the literature on indirect overlay posterior restorations as a minimally invasive alternative to the placement of full coverage crowns, their survival, resistance to fracture, preparation design and biomimetic considerations. Methodology: An electronic search was carried out through PubMed (MEDLINE), Google Scholar and Cochrane Library, using the terms: "overlay", "partial crown", AND "ceramic" or "porcelain" AND "survival" or "resistance" AND "design". Results: Overlay restorations show an acceptable medium and long-term survival rate like that of conventional full coverage crowns. The main mode of failure is ceramic fracture, followed by adhesion failure. The resistance to fracture is influenced by the physical properties of the restorative material, the cementing agent used and the design of the preparation; the latter being the most influential and characteristic factor of overlay restorations that confer biomimetic advantages superior to conventional crowns. Conclusion: Lithium disilicate overlay restorations have a satisfactory long-term survival rate. The technique allows for minimally invasive restorations, increased resistance to fracture and prolongs the restorative life cycle of the dental organ.