A systematic review and meta analysis of the longevity of anterior and posterior all-ceramic crowns

Abstract Background Clinical experience suggests that there is a difference in survival between anterior and posterior all ceramic restorations. Objectives This systematic review compared the difference in survival for full coverage all-ceramic materials used in adults to restore anterior or posterior vital teeth, not involved with fixed dental prostheses, but opposed by teeth. Data and sources Searches using Medline, Embase, and the Cochrane Library, including hand searches, with the inclusion criteria containing all-ceramic full coverage crowns in human adults over 17 years of age, prospective and retrospective studies, opposed by teeth, periodontal pocketing ≤5 mm, but not involving implant supported crowns or non-vital teeth. All papers were published between 1980 and March 2014 and available in English. From the selected studies a meta analysis was undertaken. The chi square test, I 2 , Begg’s and Egger’s test were analysed and the publication bias was assessed using a Funnel plot. The, Kappa scores were 0.63, 0.88, and 0.81 at each selection stage. Study selections Pooled data produced 1112 anterior crowns with 73 failures (6.5%) and 1821 posterior crowns with 166 failures (9.1%) with a follow up time from 36 to 223 months. Relative risk meta-analysis of the 14 selected papers demonstrated that anterior all-ceramic crowns were 50% less likely to fail than posterior all-ceramic crowns (p = 0.001). Conclusion These results indicate that there were differences in failure between anterior and posterior all ceramic crowns but the difference was only 3%. Although this has clinical relevance and some caution is needed when prescribing all ceramic posterior crowns the difference was relatively small. Clinical significance The clinically relevant results of this review, based on currently available data, demonstrate a need for some caution when considering posterior all-ceramic crowns. Lithium disilicate restorations were observed to have higher failures on anterior restorations and more research is needed to investigate why.