All-Ceramic or Metal-Ceramic Tooth-Supported Fixed Dental Prostheses (FDPs) PDF

d e n t a l m a t e r i a l s 3 1 ( 2 0 1 5 ) 624–639 Available online at www.sciencedirect.com ScienceDirect journal homepage: www.intl.elsevierhealth.com/journals/...

d e n t a l m a t e r i a l s 3 1 ( 2 0 1 5 ) 624–639 Available online at www.sciencedirect.com ScienceDirect journal homepage: www.intl.elsevierhealth.com/journals/dema Review All-ceramic or metal-ceramic tooth-supported fixed dental prostheses (FDPs)? A systematic review of the survival and complication rates. Part II: Multiple-unit FDPs夽 Bjarni Elvar Pjetursson a,∗ , Irena Sailer b , Nikolay Alexandrovich Makarov b , Marcel Zwahlen c , Daniel Stefan Thoma d a Division of Reconstructive Dentistry, Faculty of Odontology, University of Iceland, Reykjavík, Iceland b Division of Fixed Prosthodontics and Biomaterials, Clinic of Dental Medicine, University of Geneva, Switzerland c Institute of Social and Preventive Medicine, University of Berne, Berne, Switzerland d Clinic of Fixed and Removable Prosthodontics and Dental Material Science, University of Zurich, Zurich, Switzerland a r t i c l e i n f o a b s t r a c t Article history: Objective. To assess the 5-year survival of metal-ceramic and all-ceramic tooth-supported Received 7 July 2014 fixed dental prostheses (FDPs) and to describe the incidence of biological, technical and Received in revised form esthetic complications. 24 February 2015 Methods. Medline (PubMed), Embase and Cochrane Central Register of Controlled Trials (CEN- Accepted 27 February 2015 TRAL) 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 Keywords: and complication rates were analyzed using robust Poisson’s regression models to obtain All-ceramic summary estimates of 5-year proportions. Metal-ceramic Results. Forty studies reporting on 1796 metal-ceramic and 1110 all-ceramic FDPs fulfilled the Fixed partial dentures inclusion criteria. Meta-analysis of the included studies indicated an estimated 5-year sur- Systematic review vival rate of metal-ceramic FDPs of 94.4% (95% CI: 91.2–96.5%). The estimated survival rate Survival of reinforced glass ceramic FDPs was 89.1% (95% CI: 80.4–94.0%), the survival rate of glass- Success infiltrated alumina FDPs was 86.2% (95% CI: 69.3–94.2%) and the survival rate of densely Longitudinal sintered zirconia FDPs was 90.4% (95% CI: 84.8–94.0%) in 5 years of function. Even though Failures the survival rate of all-ceramic FDPs was lower than for metal-ceramic FDPs, the differences Technical complications did not reach statistical significance except for the glass-infiltrated alumina FDPs (p = 0.05). A Biological complications 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 夽 This paper was originally intended for publication with the set of papers from the Academy of Dental Materials Annual Meeting, 8–11 October 2014, Bologna, Italy; published in DENTAL 31/1 (2015). ∗ Corresponding author at: Department of Reconstructive Dentistry, Faculty of Odontology, University of Iceland, Vatnsmyrarvegi 16, 101 Reykjavik, Iceland. Tel.: +354 525 4871. E-mail address: [email protected] (B.E. Pjetursson). http://dx.doi.org/10.1016/j.dental.2015.02.013 0109-5641/© 2015 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.  d e n t a l m a t e r i a l s 3 1 ( 2 0 1 5 ) 624–639 625 (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. Conclusions. 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 rein- forced 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. © 2015 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved. Contents 1. Introduction.................................................................................................................. 625 2. Materials and methods...................................................................................................... 627 2.1. Search strategy........................................................................................................ 627 2.2. Focused questions.................................................................................................... 627 2.3. PICO.................................................................................................................... 627 2.4. Search terms.......................................................................................................... 627 2.5. Inclusion criteria...................................................................................................... 627 2.6. Exclusion criteria...................................................................................................... 627 2.7. Selection of studies................................................................................................... 627 2.8. Data extraction and method of analysis............................................................................. 627 2.9. Statistical analysis.................................................................................................... 629 3. Results........................................................................................................................ 629 3.1. Study characteristics.................................................................................................. 629 3.2. FDP survival........................................................................................................... 630 3.3. Biological complications.............................................................................................. 633 3.3.1. Secondary caries............................................................................................. 633 3.3.2. Loss of vitality................................................................................................ 635 3.3.3. Abutment tooth fracture..................................................................................... 635 3.3.4. Periodontal disease.......................................................................................... 635 3.4. Technical complications.............................................................................................. 635 3.4.1. Material complications: framework fracture, ceramic chipping or ceramic fracture..................... 635 3.4.2. Loss of retention............................................................................................. 636 3.4.3. Marginal discoloration....................................................................................... 636 4. Discussion.................................................................................................................... 636 5. Conclusion.................................................................................................................... 638 Conflict of interest........................................................................................................... 638 Acknowledgments........................................................................................................... 638 Excluded studies and reasons for exclusion................................................................................ 638 References.................................................................................................................... 638 1. Introduction complication rates for both types of reconstructions. Whereas for implant-supported reconstructions, systematic reviews Socio-economic factors, better prophylaxis and oral hygiene provide very recent evidence comparing metal- and all- regimens with patients included in regular recall programs ceramic reconstructions [3,4], a systematic pooling of newer have led to an increased number of teeth and to a shift clinical data on tooth-supported reconstructions is limited to from fully to more partially edentulous patients over the all-ceramic reconstructions. past decades. This resulted in more single and multi- Traditionally, metal-based reconstructions for fixed den- ple tooth gaps that can be restored with fixed tooth- or tal prostheses (FDPs) were considered as the gold standard implant-supported reconstructions. In order to support the. Alloys, mainly gold-based, were fully or partially veneered decision-making process for either one option, evidence- with feldspathic ceramics. The evolution in material sci- based clinical data are needed reporting on survival and ence led to the introduction of new framework materials 626 d e n t a l m a t e r i a l s 3 1 ( 2 0 1 5 ) 624–639 (ceramics) and partially a change in clinical concepts (e.g. In a systematic review, analyzing the survival and monolithic rather than veneered framework materials) [7–10]. complications rates of all-ceramic and metal-ceramic recons- Ceramics as part of reconstructive materials fulfill the tructions, an imbalance in terms of the number of studies need for esthetics. However, low-strength materials such for all-ceramic and metal-based FDPs was observed. Clin- as feldspathic-based ceramics and (reinforced) glass-ceramic ical studies on newer materials such as zirconia, lithium materials appear to be more suitable for single crowns than disilicate reinforced glass ceramics and glass-infiltrated for FDPs [7,11]. In order to overcome the limited mate- alumina (In-Ceram Alumina) or glass-infiltrated alumina- rial properties, high-strength ceramics were introduced in zirconia (Inceram-Zirconia) were available, but only few of dentistry. Zirconia as the most stable of these materials is them provided longer term data. Since that time, the evidence available for CAD/CAM technology and offers a higher flex- increased and clinical data are available for a number of all- ural strength (900–1400 MPa) and a higher fracture toughness ceramic materials for FDPs. The aim of the present systematic (5–10 MPa m1/2 ) [12,13]. Zirconia is mainly used as a framework review was therefore, material for single crowns and FDPs [14–16]. Zirconia used as framework material appears to withstand the clinical forces (i) to update the previous systematic review on tooth- during chewing and regular function and fracture rates are low supported FDPs with an additional literature search and comparable to metal-based FDPs. However, in contrast including retrospective and prospective studies from 2007 to metal-based FDPs, a higher rate of technical complications to 2013; (major chippings) was reported [18,19]. The adhesion between (ii) to assess the 3-year survival rate of tooth-supported fixed zirconia and veneering ceramics is reported to be the critical dental prostheses (FDPs) and to describe the rate of bio- issue for this observation. logical, technical and esthetic complications; First electronic search 580 Titles Independently selected by 2 reviewers 71 titles Agreed by both 71 titles Abstracts obtained Discussion Agreed on 71 abstracts Full text obtained Further hand searching 0 studies Total full text articles for the “fixed dental prosthesis” review: 37 Excluded full text articles: 7 [23-29] Total full text articles for single crowns 41 (Sailer et al. 2014) Articles from Sailer et al. 2007: 10 Final number of studies included: 40 Fig. 1 – Search strategy.  d e n t a l m a t e r i a l s 3 1 ( 2 0 1 5 ) 624–639 627 (iii) to compare the survival and complication rates of metal- An additional hand search was performed identifying rel- based FDPs and all-ceramic FDPs. evant studies by screening the reference list of all included publications. 2. Materials and methods 2.5. Inclusion criteria 2.1. Search strategy Clinical publications were considered if all of the follow- ing criteria were suitable: (i) human trials with a minimum This systematic review was designed as an update to a pre- amount of 10 patients with FDPs, (ii) mean follow-up of at viously prepared publication with the same objectives. For least 3 years in function, (iii) randomized controlled trials that purpose, Medline (PubMed), Embase and Cochrane Cen- (RCT), controlled clinical trials (CCT), prospective case series, tral Register of Controlled Trials (CENTRAL) searches were cohort studies, retrospective studies, (iv) patients needed to performed for clinical studies, including articles published be examined clinically, and (v) reported details of materials from December 1st, 2006 up to December 31, 2013 in the Den- characteristics, methods and results. tal literature. The search was limited to the English language (Fig. 1). 2.6. Exclusion criteria 2.2. Focused questions Studies not meeting all inclusion criteria were excluded from the review. Publications dealing with the following topics were “What are the survival and complication rates of tooth- also excluded: in vitro and preclinical studies, studies with supported FDPs after a mean observation period of at least a follow-up of less than 3 years, reports based on question- 3 years?” “Are the survival and complications rates of metal- naires, interviews and charts. ceramic and all-ceramic tooth-supported FDPs similar after a mean observation period of at least 3 years?” 2.7. Selection of studies 2.3. PICO Two authors (IS, NAM) independently screened the titles derived from the searches based on the inclusion criteria. The PICO for the present systematic review was defined as Disagreements were resolved by discussion. Following this, follows: abstracts of all titles agreed on by both authors were obtained, and screened for meeting the inclusion criteria. If no abstract P Population: subjects with anterior and/or posterior fixed was available in the database, the abstract of the printed arti- tooth-supported FDPs cle was used. Based on the selection of abstracts, articles I Intervention: all-ceramic FDP were then obtained in full text. If title and abstract did not C Comparison: metal-ceramic FDP provide sufficient information regarding the inclusion crite- O Outcome: clinical survival and technical, biological and ria, the full report was obtained as well. Again, disagreements esthetic complication rates were resolved by discussion. The final selection based on inclusion/exclusion criteria 2.4. Search terms was made for the full text articles. For this purpose Mate- rials and Methods, Results and Discussion of these studies The following four searches and search terms were applied: were screened. This step was again carried out by 2 readers (IS, NAM) and double-checked. Any questions that came up Population and intervention during the screening were discussed to aim for consensus. In crowns[MeSH] OR crown[MeSH] OR dental crowns[MeSH] addition, 15 publications from the previous systematic review OR crowns, dental[MeSH] OR Denture, Partial, Fixed[Mesh])) were included in the analyses. OR (crown*[all fields] OR fixed partial denture*[all fields] OR FPD[all fields] OR FPDs[all fields] OR fixed dental prosthe- 2.8. Data extraction and method of analysis sis[all fields] OR fixed dental prostheses[all fields] OR FDP[all fields] OR FDPs[all fields] OR bridge*[all fields] All included articles were independently screened and data comparison extracted using data extraction tables by two reviewers (DTH, ceramic[MeSH] OR ceramics[MeSH] OR metal ceramic BPJ). Any disagreements were resolved by discussion to aim restorations[MeSH])) OR (ceramic*[All Fields] OR all- for consensus. In addition, data of the included publications ceramic[all fields] OR Dental Porcelain[All Fields] OR of the previously published review were extracted as well. metal-ceramic[All Fields] Data on the following parameters were extracted: author(s), outcome year of publication, study design, planned number of patients, Survival[Mesh] OR survival rate[Mesh] OR survival analy- actual number of patients at end of study, drop-out rate, sis[Mesh] OR dental restoration failure[Mesh] OR prosthesis mean age, age range, operators, material framework, brand failure[Mesh] OR treatment failure[Mesh]. name of framework material, veneering material, brand name of veneering material, type of manufacturing procedure, The search combination in the builder was “population number of FDPs, number of abutment teeth, number of AND intervention AND comparison AND outcome”. (non)vital abutment teeth, number of pontics, location of FDP  628 Table 1 – Study and patient characteristics of the reviewed studies for all-ceramic FPDs. Study Year of Framework material Study No. of patients Age Mean Setting Drop-out publication design in study range age (in percent) Sola-Ruiz et al. 2013 Lithium disilicate reinforced glass ceramic Prosp. 19 n.r. 49 University 0% Rinke et al. 2013 Zirconia Prosp. 75 26–76 49.4 University 19% Raigrodski et al. 2012 Zirconia Prosp. 16 36–60 48 University 6% Peleaz et al. 2012 Zirconia RCT 37 23–65 n.r. University 0% Sagitkaya et al. 2012 Zirconia Prosp. 28 n.r. 38 University 0% Kern et al. 2012 Lithium disilicate reinforced glass ceramic Prosp. 28 n.r. 47.5 University 7% d e n t a l m a t e r i a l s 3 1 ( 2 0 1 5 ) 624–639 Lops et al. 2012 Zirconia Prosp. 28 n.r. 46.2 University 14% Sax et al. 2011 Zirconia Prosp. 45 n.r. 48.3 University 53% Sorrentino et al. 2011 Zirconia Prosp. 37 21–68 45.3 University 0% Makarouna et al. 2011 Lithium disilicate reinforced glass ceramic RCT 19 n.r. 47 University 26% Schmitt et al. 2011 Zirconia Prosp. 15 29–73 50.1 University 0% Christensen and Ploeger 2010 Zirconia and glass-infiltrated alumina RCT 259 16–89 50 Private practice multi-center 4% Beuer et al. 2010 Zirconia Prosp. 38 27–71 50.9 University 0% Roediger et al. 2010 Zirconia Prosp. 75 26–76 49.4 University 11% Wolfart et al. 2009 Lithium disilicate reinforced glass ceramic Prosp. 29 25–68 47.9 Multi-Center 7% Eschbach et al. 2009 Glass-infiltrated alumina-zirconia Prosp. 58 n.r. 46.8 University 3% Sailer et al. 2009 Zirconia RCT 59 n.r. 54.4 University 5% Wolfart et al. 2009 Zirconia Prosp. 48 23–75 55 University 4% Beuer et al. 2009 Zirconia Prosp. 19 27–71 50.9 University 0% Edelhoff et al. 2008 Zirconia Prosp. 18 n.r. n.r. University 6% Molin and Karlsson 2008 Zirconia Prosp. 18 40–84 59 Specialists and private practice 0% Tinschert et al. 2008 Zirconia Prosp. 46 20–58 n.r. University 13% Esquivel et al. 2008 Lithium disilicate reinforced glass ceramic Prosp. 21 30–62 n.r. University 0% Wolfart et al. 2005 Lithium disilicate reinforced glass ceramic Prosp. 29 25–68 47.8 University 17% Marquart and Strub 2005 Lithium disilicate reinforced glass ceramic Prosp. 43 22–65 39.9 University 0% Suàrez et al. 2004 Glass-infiltrated alumina-zirconia Prosp. 16 23–50 n.r. University 0% Olsson et al. 2003 Glass-infiltrated alumina Retrosp. 37 28–84 54 Private practice 16% Vult von Steyern et al. 2001 Glass-infiltrated alumina Prosp. 18 25–70 n.r. University and private practice 0% Sorensen et al. 1998 Glass-infiltrated alumina Prosp. 47 19–66 n.r. University 2% n.r., “not reported”; RCT, randomized controlled clinical trial.  d e n t a l m a t e r i a l s 3 1 ( 2 0 1 5 ) 624–639 629 (anterior, posterior, maxilla, mandible), reported mean follow- (in percent) Drop-out up, follow-up range, published FDP survival rate, number of FDPs lost (anterior, posterior), reported biological complica- 16% 14% 71% 56% 17% 18% 19% 17% n.r. n.r. n.r. n.r. 0% 7% tions (caries, periodontal, root fracture), reported technical 4 complications (framework fracture, minor chipping, major chipping, loss of retention), esthetic complications (marginal Private practice multi-center discoloration), reported number of patients free of complica- tions. Based on the included studies, the FDP survival rate was University Students University Students University Students University Students University students calculated. In addition, the number of events for all technical, Single specialist biological and esthetic complications was extracted and the Private practice Setting corresponding total exposure time of the reconstruction was University University University University University University University calculated. 2.9. Statistical analysis Failure and complication rates were calculated by dividing the number of events (failures or complications) in the numerator Mean age by the total FDP exposure time in the denominator. 56.8 66.8 50.3 55.3 54.4 The numerator could usually be extracted directly from the n.r. n.r. n.r. n.r. n.r. n.r. 61 47 62 50 publication. The total exposure time was calculated by taking the sum of: Age range (1) Exposure time of FDPs that could be followed for the whole 39–90 23–65 34–84 21–64 36–84 16–89 27–69 13–74 39–82 26–72 observation time. n.r. n.r. n.r. n.r. n.r. (2) Exposure time up to a failure of the FDPs that were lost due to failure during the observation time. (3) Exposure time up to the end of observation time for No. of patients FDPs that did not complete the observation period due in study Table 2 – Study and patient characteristics of the reviewed studies for metal-ceramic FPDs. to reasons such as death, change of address, refusal 149 37 52 96 18 84 259 23 59 270 45 30 357 132 58 to participate, non-response, chronic illnesses, missed appointments and work commitments. For each study, event rates for the FDPs were calculated by dividing the total number of events by the total FDP exposure n.r., “not reported”; Co-Cr, cobalt-chromium; RCT, randomized controlled clinical trial. time in years. For further analysis, the total number of events Study design Retrosp. Retrosp. Retrosp. Retrosp. Retrosp. Retrosp. Retrosp. Retrosp. Retrosp. Retrosp. was considered to be Poisson distributed for a given sum of Prosp. FDP exposure years and Poisson regression with a logarithmic RCT RCT RCT RCT link-function and total exposure time per study as an offset variable were used. Robust standard errors were calculated to obtain 95% con- Framework material fidence intervals of the summary estimates of the event Gold metal Gold metal Gold metal Gold metal Gold metal Gold metal Gold metal Gold metal Gold metal Gold metal Gold metal Titanium rates. To assess heterogeneity of the study specific event Co-Cr Co-Cr Co-Cr rates, the Spearman goodness-of-fit statistics and associated p-value were calculated. If the goodness-of-fit p-value was below 0.05. Five-year survival proportions were calculated via the relationship between event rate and survival function S, publication S(T) = exp(−T × event rate), by assuming constant event rates Year of. The 95% confidence intervals for the survival proportions 2013 2012 2012 2013 2011 2011 2010 2010 2009 2008 2007 2003 2002 2002 1989 were calculated by using the 95% confidence limits of the event rates. Multivariable Poisson regression was used to formally compare construction subtypes and to assess other study characteristics. All analyses were performed using Stata® , ver- Reichen-Graden and Lang sion 13.1. Napankangas et al. Christensen et al. Makarouna et al. 3. Results De Backer et al. Hochman et al. Svanborg et al. Boeckler et al. Eliasson et al. Brägger et al. Wolleb et al. Heschl et al. Peleaz et al. Sailer et al. 3.1. Study characteristics Walton Study A total of 40 studies fulfilled the inclusion criteria of the present systematic review. Seven studies were excluded for 630 d e n t a l m a t e r i a l s 3 1 ( 2 0 1 5 ) 624–639 various reasons, ranging from multiple publications on the 3.2. FDP survival same patient cohort to insufficiently reported data on FDPs [23–29]. 28 studies, published between 1998 and 2013, on For metal-ceramic FDPs, 15 studies provided data on 1796 FDPs all-ceramic FDPs and 15 studies, published between 1989 after a mean follow-up time of 7.0 years. Out of these, 145 and 2013, on metal ceramic FDPs, were included in this FDPs were reported to be lost. The annual failure rate was esti- review (Tables 1 and 2). The median year of publications mated at 1.15% (95% CI: 0.72–1.84%) (Fig. 2), translating into a for all-ceramic FDPs was 2009 and for metal-ceramic FDPs 5-year survival rate for metal-ceramic FDPs of 94.4% (95% CI: 2010. For all-ceramic FDPs, the majority or 28 studies had 91.2–96.5%) (Table 3). a prospective design and only one had a retrospective The results for all-ceramic FDPs was divided split into design. In contrast, for metal-ceramic FDPs the majority reconstructions based on reinforced glass ceramic, glass- of the included studies or 10 were retrospective and the infiltrated alumina (InCeram Alumina and InCeram Zirconia) remaining 5 studies were prospective. Four of the included and densely sintered zirconia. For reinforced glass ceramic studies (Peleaz et al., 2012, Makarouna, 2011, Christensen, FDPs, 7 studies provided data on 208 FDPs. After a mean follow- 2010 and Sailer et al., 2009) were randomized controlled up time of 6.0 years, 29 FDPs were reported to be lost. The clinical trails comparing different types of all-ceramic FDPs annual failure rate was estimated at 2.31% (95% CI: 1.23–4.35%) with metal-ceramic FDPs. The included studies on all- (Fig. 3) translating into a 5-year survival rate for reinforced ceramic FDPs reported on reconstructions made out of glass ceramic FDPs of 89.1% (95% CI: 80.4–94.0%) (Table 3). For reinforced glass ceramics, glass-infiltrated alumina (InCeram glass-infiltrated alumina FDPs, 6 studies provided data on 229 Alumina), glass-infiltrated alumina-zirconia (InCeram Zirco- FDPs. After a mean follow-up time of 4.1 years, 28 FDPs were nia), and densely sintered zirconia (Table 1). The studies reported to be lost. The annual failure rate was estimated at of metal-ceramic FDPs reported on reconstructions having 2.97% (95% CI: 1.20–7.35%) (Fig. 4) translating into a 5-year sur- framework out of gold metal, cobalt chromium or titanium vival rate for glass-infiltrated alumina FDPs of 86.2% (95% CI: (Table 2). 69.3–94.2%) (Table 3). For densely sintered zirconia FDPs, 16 The majority of the included studies, or 35 out of 40 studies provided data on 673 FDPs from which 62 FDPs were were conducted in university settings. The remaining stud- reported to be lost after a mean follow-up time of 4.5 years. The ies were executed in specialist clinics or private practices annual failure rate was estimated at 2.02% (95% CI: 1.24–3.31%) (Tables 1 and 2). (Fig. 5) translating into a 5-year survival rate for densely sin- The 29 studies using all-ceramic materials included 1225 tered zirconia FDPs of 90.4% (95% CI: 84.8–94.0%) (Table 3). patients, where as the 15 studies on metal-ceramic FDPs At the 5-year follow-up, the annual failure rates of different included 1669 patients. The age of the patients ranged types of FDPs ranged from 1.15% to 2.97% and the 5-year sur- between 16 and 90 years at the time of treatment. The propor- vival ranged from 86.2% to 94.4%. Investigating formally the tion of patients who could not be followed-up for the complete relative failure rates of different types of FDPs, using metal- study period was available for 90% of the studies and ranged ceramic FDPs as reference, all-ceramic FDPs showed higher from 0% to 71%. The mean drop-out rate of patients was 8% annual failure rates. Moreover, for glass-infiltrated alumina for studies reporting on all-ceramic FDPs and 19% for studies FDPs this difference reached statistical significance (p = 0.052) on metal-ceramic FDPs (Tables 1 and 2). (Table 4). Fig. 2 – Annual failure rate of metal-ceramic FDPs. Table 3 – Annual failure rates and survival of metal-ceramic and all-ceramic FDPs. Study Year of Total no. Mean No. of Total FDPs Estimated annual failure Estimated survival after publication of FDPs follow-up time failure exposure time rate* (per 100 FDP years) 5 yearsa (in percent) Metal ceramic Svanborg et al. 2013 201 4.6 7 915 0.77 96.2% Peleaz et al. 2012 20 4.2 0 83 0 100% Wolleb et al. 2012 76 5.3 1 400 0.25 98.8% Heschl et al. 2013 28 6.3 1 177 0.56 97.2% Makarouna 2011 19 2.5 1 48 2.08 90.1% Brägger et al. 2011 82 12.1 2 992 0.20 99.0% Christensen and Ploeger 2010 87 3.0 5 261 1.92 90.9% Boeckler et al. 2010 31 2.7 1 84 1.19 94.2% Sailer et al. 2009 38 2.7 0 104 0 100% De Backer et al. 2008 322 11.4 72 3675 1.96 90.7% Eliasson et al. 2007 51 4.3 3 217 1.38 93.3% d e n t a l m a t e r i a l s 3 1 ( 2 0 1 5 ) 624–639 Hochman et al. 2003 49 6.3 6 324 1.85 91.2% Walton 2002 515 7.4 37 3363 1.10 94.6% Napankangas et al. 2002 204 7.6 7 1478 0.47 97.7% Reichen-Grad and Lang 1989 73 6.4 2 465 0.43 97.9% Total 1796 7.0 145 12,586 Summary estimate (95% CI)a 1.15 (0.72–1.84) 94.4% (91.2–96.5%) Reinforced glass ceramic Sola-Ruiz et al. 2013 21 10.0 6 210 2.86 86.7% Kern et al. 2012 36 10.1 4 363 1.10 94.6% Makarouna 2011 18 4.7 6 84 7.14 70.0% Wolfart et al. 2009 36 6.9 2 247 0.81 96.0% Esquivel et al. 2008 30 3.3 5 100 5.00 77.9% Wolfart et al. 2005 36 4.0 0 120 0 100% Marquart et al. 2005 31 4.2 6 129 4.65 79.3% Total 208 6.0 29 1253 Summary estimate (95% CI) a 2.31 (1.23–4.35) 89.1% (80.4–94.0%) Glass infiltrated alumina Christensen and Ploeger 2010 23 3.0 11 69 15.9 45.1% Eschbach et al. 2009 65 4.5 2 295 0.68 96.7% Suarez et al. 2004 18 3.0 1 53 1.89 91.0% Olsson et al. 2003 42 6.3 5 266 1.88 91.0% van Steyern et al. 2001 20 5.0 2 95 2.11 90.0% Soerensen et al. 1998 61 3.0 7 165 4.24 80.9% Total 229 4.1 28 943 Summary estimate (95% CI) a 2.97 (1.20–7.35) 86.2% (69.3–94.2%) Densely sintered zirconia Rinke et al. 2013 99 6.3 19 627 3.03 85.9% 631 Raigrodski et al. 2012 20 4.7 0 94 0 100%  632 Table 3 – (Continued ) Study Year of Total no. Mean No. of Total FDPs Estimated annual failure Estimated survival after publication of FDPs follow-up time failure exposure time rate* (per 100 FDP years) 5 yearsa (in percent) Peleaz 2012 20 4.2 1 83 1.20 94.2% Lops et al. 2012 28 6.5 2 182 1.10 94.7% Sax et al. 2011 57 7.6 15 433 3.46 84.1% Sorrentino et al. 2011 48 5.0 0 240 0 100% Schmitt et al. 2011 15 4.0 0 60 0 100% Christensen and Ploeger 2010 80 3.0 14 240 5.83 74.7% Beuer et al. 2010 18 2.9 1 53 1.89 91.0% Roediger et al. 2010 99 4.2 7 413 1.69 91.9% Sailer et al. 2009 38 3.2 0 121 0 100% Wolfart et al. 2009 24 4.0 1 97 1.03 95.0% Beuer et al. 2009 21 2.5 2 53 3.77 82.8% Edelhoff et al. 2008 22 3.1 0 69 0 100% Molin and Karlsson 2008 19 5.0 0 95 0 100% Tinschert et al. 2008 65 3.1 0 202 0 100% d e n t a l m a t e r i a l s 3 1 ( 2 0 1 5 ) 624–639 Total 673 4.5 62 3062 Summary estimate (95% CI) a 2.02 (1.24–3.31) 90.4% (84.8–94.0%) Overall results 2906 6.1 264 17,844 Summary estimate (95% CI)a 1.48 (1.11–1.97) 92.9% (90.6–94.6%) a Based on robust Poisson regression. Table 4 – Summary of annual failure rates, relative failure rates and survival estimates for FDPs with metal-ceramic FDPs as reference. Type of FDPs Total number Total FDPs Mean FDPs Estimated annual 5-Year survival summary Relative failure p-Value** of FDPs exposure time follow-up time failure rate* estimate* (95% CI) rate** Metal-ceramic 1796 12,586 7.0 1.15 (0.72–1.84) 94.4% (91.2–96.5%) 1.00 (Ref.) Reinforced glass ceramic 208 1253 6.0 2.31 (1.23–4.35) 89.1% (80.4–94.0%) 2.01 (0.95–4.25) 0.068 Glass-infiltrated alumina 229 943 4.1 2.97 (1.20–7.35) 86.2% (69.3–94.2%) 2.58 (0.99–6.69) 0.052 Densely sintered zirconia 673 3062 4.5 2.02 (1.24–3.31) 90.4% (84.8–94.0%) 1.76 (0.90–3.41) 0.096 ∗ Based on robust Poisson regression. ∗∗ Based on multivariable robust Poisson regression including all types of FDPs.  d e n t a l m a t e r i a l s 3 1 ( 2 0 1 5 ) 624–639 633 Fig. 3 – Annual failure rate of reinforced glass ceramic FDPs. 3.3. Biological complications zirconia FDPs. Investigating the relative complication rates of different types of FDPs, using metal-ceramic FDPs as refer- 3.3.1. Secondary caries ence, densely sintered zirconia FDPs experienced significantly Eighteen studies reported on the incidence of secondary caries higher rate of secondary caries (p = 0.001) (Table 6). on the abutment level. From 3351 FDP abutments included Information about loss of the entire reconstruction due in those studies, 52 abutments developed secondary caries. to secondary caries was given in 38 studies. From 2145 FDPs The overall annual complication rate was 0.29%, translating included in these studies 55 were lost due to secondary caries. into a 5-year complication rate of 1.4% (Table 5). For different The overall annual failure rate was 0.43%, translating into a types of FDPs the annual rate of secondary caries ranged from 5-year failure rate of 2.1% (Table 5). For different types of FDPs 0.11% to 0.65%. The lowest annual complication rate 0.11% the annual rate of failures due to caries ranged from 0.09% was reported for reinforced glass ceramic FDPs and the high- to 0.54%. The lowest annual failure rate 0.09% was reported est complication rate 0.65% was reported for densely sintered for reinforced glass ceramic FDPs and the highest failure rates Fig. 4 – Annual failure rate of glass-infiltrated alumina FDPs.  634 Table 5 – Overview of biological and technical complications of different types of FDPs. Complication Number of Estimated Cumulative Number of Estimated Cumulative Number of Estimated Cumulative abutments or annual 5-year abutments or annual 5-year abutments or annual 5-year FDPs complication complication FDPs complication complication FDPs complication complication rates (95% CI) rates (95% CI) rates (95% CI) rates (95% CI) rates (95% CI) rates (95% CI) Overall results – all FDPs Metal ceramic FDPs Reinforced glass ceramic FDPs * * * * Caries on abutments 3351 0.29 (0.14–2.94) 1.4% (0.7–2.9%) 2497 0.24 (0.10–0.57) 1.2% (0.5–2.8%) 199 0.11* (0.01–0.94) 0.5%* (0.06–4.6%) FDPs lost due to caries 2145 0.43* (0.21–0.88) 2.1%* (1.1–4.3%) 1053 0.54* (0.24–1.22) 2.7%* (1.2–5.9%) 190 0.09* (0.01–0.76) 0.4%* (0.05–3.7%) FDPs lost due to 2096 0.23* (0.10–0.54) 1.2%* (0.5–2.7%) 1004 0.06* (0.03–0.11) 0.3%* (0.1–0.6%) 190 0.60* (0.10–3.52) 2.9%* (0.5–16.1%) periodontal disease FDPs lost due to 2107 0.17* (0.12–0.25) 0.9%* (0.6–1.3%) 1053 0.19* (0.11–0.30) 0.9%* (0.6–1.5%) 190 0.09* (0.02–0.44) 0.4%* (0.1–2.2%) abutment tooth fracture Loss of abutment tooth 243 0.44* (0.11–1.80) 2.2%* (0.5–8.6%) n.a. n.a. n.a. n.a. n.a. n.a. d e n t a l m a t e r i a l s 3 1 ( 2 0 1 5 ) 624–639 vitality Marginal discolorations 253 3.91* (1.46–10.46) 17.7%* (7.0–40.7%) 20 4.82* (1.33–11.88) 21.4%* (6.4–44.8%) 118 0.72.* (0.23–2.19) 3.5%* (1.2–10.4%) Framework fracture 2640 0.45* (0.25–0.82) 2.2%* (1.2–4.0%) 1530 0.12* (0.04–0.40) 0.6%* (0.2–2.0%) 208 1.68* (0.84–3.33) 8.0%* (4.1–15.3%) Ceramic fractures 2129 1.56* (0.85–2.86) 7.5%* (4.2–13.3%) 1305 1.03* (0.42–2.56) 5.0%* (2.1–12.0%) 187 1.34* (0.99–1.82) 6.5%* (4.8–8.7%) Ceramic chipping 1659 2.71.* (1.52–4.83) 12.7%* (7.3–21.4%) 781 1.79* (0.81–3.96) 8.6%* (4.0–18.0%) 213 1.07* (0.48–2.36) 5.2%* (2.4–11.1%) Loss of retention 1702 0.64* (0.35–1.16) 3.1%* (1.7–5.6%) 955 0.42* (0.16–1.09) 2.1%* (0.8–5.3%) 142 0.58* (0.35–0.97) 2.9%* (1.7–4.7%) Complication Number of Estimated Cumulative Number of Estimated Cumulative abutments or annual 5-year abutments or annual 5-year FDPs complication complication FDPs complication complication rates (95% CI) rates (95% CI) rates (95% CI) rates (95% CI) Glass-infiltrated alumina FDPs Densely sintered zirconia FDPs Caries on abutments 168 0.41* (0.22–0.74) 2.0%* (1.1–3.6%) 487 0.65* (0.27–1.56) 3.2%* (1.3–7.5%) FDPs lost due to caries 229 0.11* (0.02–0.56) 0.5%* (0.1–2.8%) 673 0.39* (0.20–0.77) 1.9%* (1.0–3.8%) FDPs lost due to 229 1.59* (0.62–4.08) 7.6%* (3.1–18.4%) 673 0.10* (0.03–0.30) 0.5%* (0.2–1.5%) periodontal disease FDPs lost due to 229 0.11* (0.01–1.02) 0.5%* (0.05–5.0%) 635 0.21* (0.11–0.38) 1.0%* (0.6–1.9%) abutment tooth fracture Loss of abutment tooth n.a. n.a. n.a. 243 0.44* (0.11–1.80) 2.2%* (0.5–8.6%) vitality Marginal discolorations 18 3.77* (0.46–12.98) 17.2%* (2.3–47.7%) 97 6.72* (3.30–13.68) 28.5%* (15.2–49.5%) Framework fracture 229 2.76* (1.01–7.52) 12.9%* (4.9–31.3%) 673 0.39* (0.24–0.65) 1.9%* (1.2–3.2%) Ceramic fractures 65 1.36* (0.37–3.44) 6.6%* (1.8–15.8%) 572 3.14* (2.37–4.17) 14.5%* (11.2–18.8%) Ceramic chipping 90 7.55* (1.09–52.24) 31.4%* (5.3–92.7%) 575 4.33* (1.93–9.72) 19.5%* (9.2–38.5%) Loss of retention 107 0.53* (0.31–0.93) 2.6%* (1.5–4.5%) 498 1.28* (0.83–1.97) 6.2%* (4.1–9.4%) n.a., “not available”. ∗ Based on robust Poisson regression.  d e n t a l m a t e r i a l s 3 1 ( 2 0 1 5 ) 624–639 635 0.39% and 0.54% for densely sintered zirconia FDPs and metal- p-Value* Densely sintered zirconia FDPs ceramic FDPs, respectively. The difference between different 0.001 0.535 0.384 0.784 0.289 0.069 0.018 0.115 0.028 types of FDPs did not reach statistical significance (p = 0.064, 0.095 & 0.535) (Table 6). 3.3.2. Loss of vitality Relative compl. rate* Loss of abutment vitality was reported in three studies. All of 3.23 (0.91–11.42) 2.75 (1.50–5.07) 0.72 (0.26–2.01) 1.77 (0.49–6.44) 1.11 (0.52–2.38) 1.39 (0.75–2.58) 3.05 (1.21–7.69) 2.42 (0.81–7.25) 3.07 (1.12–8.37) them reporting on densely sintered zirconia FDPs. Four out of 243 abutment teeth, reported to be vital at the time of cemen- tation, presented loss of pulp vitality during the observation period. The annual complication rate was 0.44%, translating into a 5-year complication rate of 2.2% (Table 5). 3.3.3. Abutment tooth fracture