This ADA-EBD critical summary has looks at a 2012 systematic review by Wang et al. The aim of the review was to evaluate the clinical fracture incidence of tooth-supported all-ceramic crowns according to restored tooth type.
The appraiser considered the reviews search strategy to be thorough but noted that the studies were not assessed for bias. It was also pointed out that if stratified by techniques it appeared that crowns fabricated by CAD/CAM and hot pressing may fail at different rates. It was also noted that only two randomised controlled trials were included and that some of the ceramic systems studies were obsolete. Frequent changes in dental materials present an challenge for researchers looking study longer term outcomes in clinical trials.
As we noted in the Dental Elf blog on this review (Dental Elf 23rd Nov 2012 ) there were 32 studies included in the review all told. The results suggesting that the 5 years survival rate for all-ceramic crowns is acceptable, although fracture rates were higher for posterior teeth.
Wang X, Fan D, Swain MV, Zhao K. A systematic review of all-ceramic crowns: clinical fracture rates in relation to restored tooth type. Int J Prosthodont. 2012 Sep-Oct;25(5):441-50. Review. PubMed PMID: 22930765.