Irena Sailer, Nikolay Alexandrovich Makarov, Daniel Stefan Thoma, Marcel Zwahlen, Bjarni Elvar Pjetursson
Context
- All-ceramic fixed dental prostheses (FDPs) are considered an established treatment alternative to metal-ceramic FDPs in daily clinical practice.
- The main reason to use of the all ceramics instead of metal-ceramics is based on more favorable esthetics 3. All-ceramic materials mimic very naturally the optical properties of teeth.
- Another more recent factor influencing the choice of materials and leading to an increasing use of all-ceramics is treatment costs, mostly due to the pronounced raise of the costs for high precious metals like gold 4.
- The main shortcoming of the firstly introduced ceramics like, e.g. feldspathic glass ceramic, yet, was low mechanical stability, which limited the indications for all-ceramic reconstructions to anterior regions and to single-unit FDPs 1.
- A systematic review of the literature demonstrated significantly higher survival rates of single crowns (SCs), e.g. made out of leucit or lithiumdisilicate reinforced glass ceramics compared to SCs made out of feldspathic ceramics (95.4% vs. 87.5%).
- Tooth-borne SCs made out of densely sintered alumina exhibited the highest survival rates (96.4%) compared to all other all-ceramic SCs.
- Furthermore, all-ceramic crowns exhibited similar survival rates as metal-ceramic crowns (93.3% vs. 95.6%) 1. In conclusion, improvements in terms of material properties such as mechanical stability of the ceramics had a positive effect on the clinical outcomes of all-ceramic reconstructions.
- Until recently, it was not possible to recommend all ceramic single or multiple-unit FDPs as clinically equivalent treatment alternative to metal ceramic FDPs. Metal-ceramics remained to be the “gold standard” type of reconstruction. Yet, a high number of new manuscripts of all-ceramic and metal ceramic single- and multiple-unit FDPs was published since the previously mentioned systematic review. The more recent studies either reported on the all-ceramic or metal-ceramic FDPs analyzed before but with longer observation periods, or on new all-ceramic FDPs made out of improved ceramic materials
Purpose of the review
To analyze the outcomes of all-ceramic and metal-ceramic FDPs, i.e. of single crowns and of multiple-unit FDPs, and to assess whether or not all-ceramic FDPs achieve similar long-term results as FDPs made out of metal-ceramics.
- To update the previous systematic review 1 on tooth supported FDPs with an additional literature search including retrospective and prospective studies from 2007 to 2013.
- To obtain overall robust estimates of the long-term survival and complication rates of all-ceramic crowns over an observation period of at least 3 years.
- To compare the survival and complication rates of all ceramic crowns with the ones of metal-ceramic crowns (gold standard).
Key Points
- All-ceramic single crowns exhibit similar survival rates as metal-ceramic single crowns after a mean observation period of at least 3 years. However, this is solely true for SCs are made out of leucit or lithium-disilicate reinforced glass ceramics or oxide ceramics.
- Those materials perform similarly well in anterior and posterior regions.
- Crowns made out of densely sintered zirconia, however, cannot be recommended as primary treatment option, due to an increased risk of chipping of the veneering ceramic and loss of retention.
- These limitations must first be overcome by further refinements of the production technology.
- Finally, the mechanically weaker ceramics like the feldspathic or silica glass-ceramics can only be recommended in anterior regions with low functional load.
References