Clinical outcomes of lithium disilicate single crowns and partial fixed dental prostheses: a systematic review

Abstract

Statement of problem: Lithium disilicate is a relatively new and popular restorative material for esthetic and functional rehabilitations, but the evidence for clinical outcomes is not clear.

Purpose: The purpose of this systematic review was to analyze the short-term (1- to 5-year) and medium-term (5- to 10-year) survival rates of lithium disilicate single crowns and partial fixed dental prostheses.

Material and methods: An electronic search for articles in the English-language literature published between January 1998 and June 2013 was performed with the PubMed search engine. The specific search terms used were lithium disilicate, lithium silicate, IPS e max, IPS Empress, CAD CAM, pressed ceramic, monolithic, and bilayer. After applying predetermined inclusion and exclusion criteria, the definitive list of selected articles was suitable only for calculating the interval survival rate and cumulative survival rate.

Results: The electronic search resulted in 2033 titles. The systematic application of inclusion and exclusion criteria resulted in 12 clinical studies that addressed the clinical outcomes of lithium disilicate restorations. Of these, 2 were randomized controlled trials, 5 were prospective studies, 1 was a retrospective study, and 4 studies were descriptive in nature. All 12 studies reported on tooth-retained lithium disilicate restorations. The 2-year cumulative survival rate for single crowns was 100%, and the 5-year cumulative survival rate was 97.8%. The 2-year cumulative survival rate for fixed dental prostheses was 83.3%, and the 5-year cumulative survival rate was 78.1%. The cumulative survival rate over a 10-year period, primarily owing to data from 1 study, was 96.7% for single crowns and 70.9% for fixed dental prostheses.

Conclusions: For lithium disilicate single crowns, the existing evidence indicates excellent short-term survival rates, but the evidence for medium-term survival is limited. For lithium disilicate fixed dental prostheses, the evidence for short-term survival is fair, although limited, but the evidence for medium-term survival is not promising. The majority of failures in both types of restorations were reported in the posterior region.