Tooth wear against ceramic crowns in posterior region: a systematic literature review

The objective of this systematic review was to assess tooth wear against ceramic crowns in posterior region in vitro and in vivo. An electronic PubMed search was conducted to identify studies on tooth wear against ceramic crowns in posterior region. The selected studies were analyzed in regard to type of crowns, natural antagonist, measuring protocol and outcome. From a yield of 1 000 titles, 43 articles were selected for full-text analysis; finally, no in vitro and only five in vivo studies met the inclusion criteria. As there is heterogeneity in design, used measuring method, ceramics and analysis-form, a meta-analysis was not possible. Results of these studies are very controversial which makes a scientifically valid comparison impossible. This review indicated that some all-ceramic crowns are as wear friendly as metal-ceramic crowns. Up to now, it has been impossible to associate tooth wear with any specific causal agent. The role of ceramic surface treatment that might be responsible for the changing in rate of tooth wear seems undetermined as yet through clinical trials. The literature reveals that studies on this topic are subject to a substantial amount of bias. Therefore, additional clinical studies, properly designed to diminish bias, are warranted. More research is needed to assess whether all-ceramic crowns accelerate the rate of tooth wear in molars and premolars, conclude two dentists in Germany who systematically reviewed the dental literature. Rim Hmaidouch and Paul Weigl from the Johann Wolfgang Goethe University in Frankfurt, searched for published studies that investigated whether a causal relationship exists between the insertions of ceramic crowns and increased wear in the posterior dental region. They found only five studies that examined the issue, including three that evaluated tooth wear in the exact same patient population. From the three independent pools of study subjects, the authors determined that some ceramic materials are wear-friendly. However, the published studies suffered from many design flaws, so they believe that additional, more rigorous clinical trials are still warranted.