To assess the 5-year survival of metal-ceramic and all-ceramic tooth-supported fixed dental prostheses (FDPs) and to describe the incidence of biological, technical and esthetic complications.
Medline (PubMed), Embase and Cochrane Central Register of Controlled Trials (CENTRAL) searches (2006–2013) were performed for clinical studies focusing on tooth-supported FDPs with a mean follow-up of at least 3 years. This was complemented by an additional hand search and the inclusion of 10 studies from a previous systematic review . Survival and complication rates were analyzed using robust Poisson’s regression models to obtain summary estimates of 5-year proportions.
Forty studies reporting on 1796 metal-ceramic and 1110 all-ceramic FDPs fulfilled the inclusion criteria. Meta-analysis of the included studies indicated an estimated 5-year survival rate of metal-ceramic FDPs of 94.4% (95% CI: 91.2–96.5%). The estimated survival rate of reinforced glass ceramic FDPs was 89.1% (95% CI: 80.4–94.0%), the survival rate of glass-infiltrated alumina FDPs was 86.2% (95% CI: 69.3–94.2%) and the survival rate of densely sintered zirconia FDPs was 90.4% (95% CI: 84.8–94.0%) in 5 years of function. Even though the survival rate of all-ceramic FDPs was lower than for metal-ceramic FDPs, the differences did not reach statistical significance except for the glass-infiltrated alumina FDPs ( p = 0.05). A significantly higher incidence of caries in abutment teeth was observed for densely sintered zirconia FDPs compared to metal-ceramic FDPs. Significantly more framework fractures were reported for reinforced glass ceramic FDPs (8.0%) and glass-infiltrated alumina FDPs (12.9%) compared to metal-ceramic FDPs (0.6%) and densely sintered zirconia FDPs (1.9%) in 5 years in function. However, the incidence of ceramic fractures and loss of retention was significantly ( p = 0.018 and 0.028 respectively) higher for densely sintered zirconia FDPs compared to all other types of FDPs.
Survival rates of all types of all-ceramic FDPs were lower than those reported for metal-ceramic FDPs. The incidence of framework fractures was significantly higher for reinforced glass ceramic FDPs and infiltrated glass ceramic FDPs, and the incidence for ceramic fractures and loss of retention was significantly higher for densely sintered zirconia FDPs compared to metal-ceramic FDPs.
Socio-economic factors, better prophylaxis and oral hygiene regimens with patients included in regular recall programs have led to an increased number of teeth and to a shift from fully to more partially edentulous patients over the past decades . This resulted in more single and multiple tooth gaps that can be restored with fixed tooth- or implant-supported reconstructions. In order to support the decision-making process for either one option, evidence-based clinical data are needed reporting on survival and complication rates for both types of reconstructions. Whereas for implant-supported reconstructions, systematic reviews provide very recent evidence comparing metal- and all-ceramic reconstructions , a systematic pooling of newer clinical data on tooth-supported reconstructions is limited to all-ceramic reconstructions .
Traditionally, metal-based reconstructions for fixed dental prostheses (FDPs) were considered as the gold standard . Alloys, mainly gold-based, were fully or partially veneered with feldspathic ceramics. The evolution in material science led to the introduction of new framework materials (ceramics) and partially a change in clinical concepts (e.g. monolithic rather than veneered framework materials) . Ceramics as part of reconstructive materials fulfill the need for esthetics. However, low-strength materials such as feldspathic-based ceramics and (reinforced) glass-ceramic materials appear to be more suitable for single crowns than for FDPs . In order to overcome the limited material properties, high-strength ceramics were introduced in dentistry. Zirconia as the most stable of these materials is available for CAD/CAM technology and offers a higher flexural strength (900–1400 MPa) and a higher fracture toughness (5–10 MPa m 1/2 ) . Zirconia is mainly used as a framework material for single crowns and FDPs . Zirconia used as framework material appears to withstand the clinical forces during chewing and regular function and fracture rates are low and comparable to metal-based FDPs . However, in contrast to metal-based FDPs, a higher rate of technical complications (major chippings) was reported . The adhesion between zirconia and veneering ceramics is reported to be the critical issue for this observation .
In a systematic review, analyzing the survival and complications rates of all-ceramic and metal-ceramic reconstructions, an imbalance in terms of the number of studies for all-ceramic and metal-based FDPs was observed . Clinical studies on newer materials such as zirconia, lithium disilicate reinforced glass ceramics and glass-infiltrated alumina (In-Ceram Alumina) or glass-infiltrated alumina-zirconia (Inceram-Zirconia) were available, but only few of them provided longer term data. Since that time, the evidence increased and clinical data are available for a number of all-ceramic materials for FDPs. The aim of the present systematic review was therefore,
to update the previous systematic review on tooth-supported FDPs with an additional literature search including retrospective and prospective studies from 2007 to 2013;
to assess the 3-year survival rate of tooth-supported fixed dental prostheses (FDPs) and to describe the rate of biological, technical and esthetic complications;
to compare the survival and complication rates of metal-based FDPs and all-ceramic FDPs.