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Introduction

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 [1]. 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,

• (i)

  to update the previous systematic review on tooth-supported FDPs with an additional literature search including retrospective and prospective studies from 2007 to 2013;

• (ii)

  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;

• (iii)

  to compare the survival and complication rates of metal-based FDPs and all-ceramic FDPs.