All-ceramic or metal-ceramic tooth-supported fixed dental ... · for Fixed Prosthodontics and Biomaterials, Center ofDental Medicine, University Geneva, Switzerland b Department ...
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d e n t a l m a t e r i a l s 3 1 ( 2 0 1 5 ) 603–623
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ll-ceramic or metal-ceramic tooth-supportedxed dental prostheses (FDPs)? A systematiceview of the survival and complication rates.art I: Single crowns (SCs)�
rena Sailera,∗, Nikolay Alexandrovich Makarova, Daniel Stefan Thomab,arcel Zwahlenc, Bjarni Elvar Pjeturssond
Division for Fixed Prosthodontics and Biomaterials, Center of Dental Medicine, University of Geneva, Geneva,witzerlandDepartment of Fixed and Removable Prosthodontics and Dental Material Science, University of Zurich, SwitzerlandDepartment of Social and Preventive Medicine, University of Berne, Berne, SwitzerlandDepartment of Reconstructive Dentistry, Faculty of Odontology, University of Iceland, Reykjavik, Iceland
r t i c l e i n f o
rticle history:
eceived 8 July 2014
eceived in revised form
4 February 2015
ccepted 25 February 2015
eywords:
ll-ceramic
ingle crowns
ystematic review
urvival
a b s t r a c t
Objective. To assess the 5-year survival of metal-ceramic and all-ceramic tooth-supported
single crowns (SCs) and to describe the incidence of biological, technical and esthetic com-
plications.
Methods. Medline (PubMed), Embase, Cochrane Central Register of Controlled Trials (CEN-
TRAL) searches (2006–2013) were performed for clinical studies focusing on tooth-supported
fixed dental prostheses (FDPs) with a mean follow-up of at least 3 years. This was com-
plimented by an additional hand search and the inclusion of 34 studies from a previous
systematic review [1,2]. Survival and complication rates were analyzed using robust Pois-
son’s regression models to obtain summary estimates of 5-year proportions.
Results. Sixty-seven studies reporting on 4663 metal-ceramic and 9434 all-ceramic SCs ful-
filled the inclusion criteria. Seventeen studies reported on metal-ceramic crowns, and 54
studies reported on all-ceramic crowns. Meta-analysis of the included studies indicated an
uccess
ongitudinal
ailures
omplication rates
echnical complications
estimated survival rate of metal-ceramic SCs of 94.7% (95% CI: 94.1–96.9%) after 5 years.
This was similar to the estimated 5-year survival rate of leucit or lithium-disilicate rein-
95% CI: 92.7–96%) and densely sintered alumina and zirconia SCs (96%; 95% CI: 93.8–97.5%;
92.1%; 95% CI: 82.8–95.6%). In contrast, the 5-year survival rates of feldspathic/silica-based
iological complications ceramic crowns were lower (p < 0.001). When the outcomes in anterior and posterior regions
� This paper was originally intended for publication with the set of papers from the Academy of Dental Materials Annual Meeting, 8–11ctober 2014, Bologna, Italy; published in DENTAL 31/1 (2015).∗ Corresponding author at: Division of Fixed Prosthodontics and Biomaterials, Center of Dental Medicine, University of Geneva, 19, Ruearthelemy-Menn, CH 1205 Geneva, Switzerland. Tel.: +41 22 379 4050.
All-ceramic fixed dental prostheses (FDPs) are considered anestablished treatment alternative to metal-ceramic FDPs indaily clinical practice. The main reason to use of the all-ceramics instead of metal-ceramics is based on more favorableesthetics [3]. All-ceramic materials mimic very naturally theoptical properties of teeth. Another more recent factor influ-encing the choice of materials and leading to an increasinguse of all-ceramics is treatment costs, mostly due to the pro-nounced raise of the costs for high precious metals like gold
reconstructions to anterior regions and to single-unit FDPs[1]. In the past years, numerous new dental ceramic materialswere developed with the aim to increase the overall stabilityof the all-ceramic reconstructions, while still maintaining theesthetic benefit. Among those materials, leucite or lithium-disilicate leucit or lithium-disilicate reinforced glass ceramicsand oxide ceramics such as alumina and zirconia appeared tobe very promising for different indications. Reconstructionsmade of these more recently developed ceramics were placedat posterior sites and even included multiple-unit FDPs [5].
Subsequently performed clinical studies confirmed theassumption that these mechanically more stable ceramic
[4].The main shortcoming of the firstly introduced ceramics
like, e.g. feldspathic glass ceramic, yet, was low mechan-ical stability, which limited the indications for all-ceramic
materials would perform better than the firstly developed
ones when used for tooth-borne FDPs. The clinical out-comes of the more recent ceramics were far better thanthe ones of the first generation of dental ceramics [1,2].
systematic review of the literature demonstrated signifi-antly higher survival rates of SCs, e.g. made out of leucitr lithium-disilicate reinforced glass ceramics compared toCs made out of feldspathic ceramics (95.4% vs. 87.5%).ooth-borne SCs made out of densely sintered alumina exhib-ted the highest survival rates (96.4%) compared to all otherll-ceramic SCs. Furthermore, all-ceramic crowns exhibitedimilar survival rates as metal-ceramic crowns (93.3% vs.5.6%) [1]. In conclusion, improvements in terms of mate-ial properties such as mechanical stability of the ceramicsad a positive effect on the clinical outcomes of all-ceramiceconstructions.
The clinical follow-up of the studies on all-ceramic FDPs,owever, was rather short. At time of the above-mentionedystematic review a limited amount of studies was available,ost of the published studies did not exceed 5 years of clinical
ollow-up. In order to be able to draw clinical conclusions withespect to the outcomes of all-ceramic reconstructions, morelinical research with longer observation periods was needed.n addition, the available clinical research indicated thatespite of all material improvements catastrophic fracturesemained to be one major issue of all-ceramic reconstructions.n addition, this problem was more often found in the poste-ior region, or for multiple-unit FDPs where high load occurred1].
Hence, until recently, it was not possible to recommend all-eramic single or multiple-unit FDPs as clinically equivalentreatment alternative to metal ceramic FDPs. Metal-ceramicsemained to be the “gold standard” type of reconstruction. Yet,
high number of new manuscripts of all-ceramic and metal-eramic single- and multiple-unit FDPs was published sincehe previously mentioned systematic review. The more recenttudies either reported on the all-ceramic or metal-ceramicDPs analyzed before but with longer observation periods, orn new all-ceramic FDPs made out of improved ceramic mate-ials.
Therefore, the aim of the present systematic review was tonalyze the outcomes of all-ceramic and metal-ceramic FDPs,.e. of single crowns and of multiple-unit FDPs, and to assess
hether or not all-ceramic FDPs achieve similar long-termesults as FDPs made out of metal-ceramics.
The objectives of this systematic review, therefore, were:
1) To update the previous systematic review [1] on tooth-supported FDPs with an additional literature searchincluding retrospective and prospective studies from 2007to 2013.
2) To obtain overall robust estimates of the long-term sur-vival and complication rates of all-ceramic crowns overan observation period of at least 3 years.
3) To compare the survival and complication rates of all-ceramic crowns with the ones of metal-ceramic crowns(gold standard).
The present part 1 of the review presents the outcomesf all-ceramic versus metal-ceramic single crowns. Part 2f the review analyzed the outcomes of the multiple-unitDPs.
( 2 0 1 5 ) 603–623 605
2. Materials and methods
2.1. Search strategy and study selection
The present review followed the same search methodology asthe previous one [1].
2.1.1. Focused questions“What are the survival and complication rates of tooth-supported FDPs after a mean observation period of at least 3years?” “Are the survival and complications rates of metal-ceramic and all-ceramic tooth-supported FDPs similar aftera mean observation period of at least 3 years?”
2.1.1.1. PICO. The population, intervention, comparison andoutcomes, i.e. the “PICO” for this systematic review wasdefined as follows:
logical complication rates.A literature search in databases PubMed, Embase, Cochrane
Central Register of Controlled Trials (CENTRAL) search wasperformed. The search was limited to human studies in dentaljournals written in English language. Articles published from1st of December 2006 up to and including the 31st of December2013 were included. The following detailed search terms wereused and the search strategy was as follows:
P and I: crowns[MeSH] OR crown[MeSH] OR dentalcrowns[MeSH] OR crowns, dental[MeSH] OR Denture, Partial,Fixed[Mesh])) OR (crown*[all fields] OR fixed partial den-ture*[all fields] OR FPD[all fields] OR FPDs[all fields] OR fixeddental prosthesis[all fields] OR fixed dental prostheses[allfields] OR FDP[all fields] OR FDPs[all fields] OR bridge*[allfields].
C: Ceramic[MeSH] OR ceramics[MeSH] OR metalceramic restorations[MeSH])) OR (ceramic*[All Fields] ORall-ceramic[all fields] OR Dental Porcelain[All Fields] ORmetal-ceramic[All Fields].
O: Survival[Mesh] OR survival rate[Mesh] OR survival anal-ysis[Mesh] OR dental restoration failure[Mesh] OR prosthesisfailure[Mesh] OR treatment failure[Mesh].
The combination in the builder was set as “P & I AND CAND O”.
The electronic search was complemented by manualsearches of the bibliographies of all full text articles andrelated reviews, selected from the electronic search. Thesearch was independently performed by two researches (ISand NAM). Any disagreement was resolved in consensusbetween the authors.
Up to the level of data extraction, the literature was evalu-ated for both single crowns and multiple-unit FDPs at the sametime. At full text level the manuscripts were split according tothe reconstruction type.
Besides the mentioned RCTs, this systematic review was basedon prospective or retrospective cohort studies, or case series.
The additional inclusion criteria for study selection were:
• Studies with a minimum mean follow-up period of 3 years.• Included patients had been examined clinically at the
follow-up visits, i.e. publications based on patient recordsonly, on questionnaires or interviews were excluded.
• Studies reported details on the characteristics of the recons-tructions, on materials and methods and on the results.
• Studies had to include and follow-up at least 10 patients.• Publications which combined findings of tooth and implant
supported reconstructions where at least 90% was toothsupported reconstructions.
The final selection based on inclusion/exclusion criteriawas made for the full text articles. For this purpose Sections2–4 of these studies were screened. This step was again car-ried out by two readers (IS, NAM) and double-checked. Anyquestions that came up during the screening were discussedto aim for consensus.
2.3. Exclusion criteria
The following study types were excluded:
• in vitro or animal studies;• studies with less than 3 years of follow-up; and• studies based on chart reviews or interviews.
2.4. Selection of studies
Titles and abstracts of the searches were independentlyscreened by two reviewers (IS & NAM) for possible inclusion inthe review. Furthermore, the full text of all studies of possiblerelevance was then obtained and split into literature on singlecrowns (part 1 of the review) and literature on multiple-unitFDPs (part 2 of the review).
The literature on single crowns was independentlyassessed by three of the reviewers (IS, BEP & NAM). Any dis-agreement regarding inclusion was resolved by discussion.
2.5. Data extraction
Data on the following parameters were extracted: author(s),year of publication, study design, planned number of patients,actual number of patients at end of study, drop-out rate, meanage, age range, operators, material framework, brand nameof framework material, veneering material, brand name ofveneering material, type of manufacturing procedure, num-ber of FDPs, number of abutment teeth, number of (non)vitalabutment teeth, number of pontics, location of FDP (ante-rior, posterior, maxilla, mandible), reported mean follow-up,follow-up range, published FDP survival rate, number of
FDPs lost (anterior, posterior), reported biological complica-tions (caries, periodontal, root fracture), reported technicalcomplications (framework fracture, minor chipping, majorchipping, loss of retention), esthetic complications (marginal
1 ( 2 0 1 5 ) 603–623
discoloration), reported number of patients free of complica-tions. Based on the included studies, the FDP survival rate wascalculated. In addition, the number of events for all technical,biological and esthetic complications was extracted and thecorresponding total exposure time of the reconstruction wascalculated.
Data was extracted independently by two reviewers (IS &NAM) using a data extraction form. Disagreement regardingdata extraction was resolved by consensus of three reviewers(IS, BEP & NAM).
2.6. Statistical analysis
For the statistical analysis the new data of the present review,encompassing the 33 studies was combined with the previousdata of the 34 studies published in Pjetursson et al., 2007.
Hence, the data included in the present analysis was pub-lished from 1990 until the end of 2013.
Survival was defined as the FDP remaining in situ with orwithout modification for the observation period.
Failure and complication rates were calculated by divid-ing the number of events (failures or complications) in thenumerator by the total FDP exposure time in the denominator.
The numerator could usually be extracted directly from thepublication. The total exposure time was calculated by takingthe sum of:
(1) Exposure time of FDPs that could be followed for the wholeobservation time.
(2) Exposure time up to a failure of the FDPs that were lostdue to failure during the observation time.
(3) Exposure time up to the end of observation time forFDPs that did not complete the observation period dueto reasons such as death, change of address, refusalto participate, non-response, chronic illnesses, missedappointments and work commitments.
For each study, event rates for the FDPs were calculated bydividing the total number of events by the total FDP exposuretime in years. For further analysis, the total number of eventswas considered to be Poisson distributed for a given sum ofFDP exposure years and Poisson regression with a logarithmiclink-function and total exposure time per study as an offsetvariable were used [6].
Robust standard errors were calculated to obtain 95% con-fidence intervals of the summary estimates of the eventrates. To assess heterogeneity of the study specific eventrates, the Spearman goodness-of-fit statistics and associatedp-value were calculated. If the goodness-of-fit p-value wasbelow 0.05 five year survival proportions were calculated viathe relationship between event rate and survival function S,S(T) = exp(−T * event rate), by assuming constant event rates[7]. The 95% confidence intervals for the survival proportionswere calculated by using the 95% confidence limits of the event
rates. Multivariable Poisson regression was used to formallycompare construction subtypes and to assess other studycharacteristics. All analyses were performed using Stata®, ver-sion 13.1.
From this extensive new search, one randomized controlledclinical trial (RCT) was available comparing all-ceramic singlecrowns with conventional metal-ceramic crowns [8]. This RCTcompared zirconia-based SCs with metal-ceramic SCs [8]. Nofurther RCT comparing all-ceramic and metal-ceramic crownswas available. However, one RCT compared crowns made offeldspathic ceramic and glass-infiltrated alumina [9]. Finally,one RCT compared two types of metal-ceramic crowns [10].
Fig. 1 describes the process of identifying the 71 full textarticles selected from an initial yield of 580 titles that werefound published in the period from the 1st of December 2006to the 31st of December 2013.
From these, 41 full text articles were allocated to the “singlecrown” group, whereas 37 were allocated to the group repor-ting on “multiple-unit FDPs”.
3.1. Study characteristics
3.1.1. Included studiesThe final number of the new studies included in the analysesresulted as 33 studies. Information on the survival proportionsof the single crowns was extracted from these included 33studies. In addition, the data from 34 publications from theprevious systematic review [1] was included in the analyses.
The details on the previously included studies as well asthe references are given in Pjetursson et al., 2007, and inTables 1 and 2. The newly included 33 studies on all-ceramicand/or metal-ceramic single crowns were published between2006 and 2013 (Tables 1 and 2).
Out of these studies, four were designed as RCTs. How-ever, only one RCT compared all-ceramic (zirconia-based) andmetal-ceramic crowns. All other RCTs compared either twodifferent types of all-ceramics or of metal-ceramics, or all-ceramic and resin-based single crowns.
Furthermore, 14 “new” studies were reporting onmetal-ceramic crowns, four on crowns made out offeldspathic/silica-based ceramics (jacket crowns, 3G OPC,Noritake feldspathic, Dicor), six on reinforced glass-ceramiccrowns (one study on Empress 1 [11], the remaining onEmpress 2 or E.max), three on glass-infiltrated aluminacrowns (InCeram), three on densely sintered alumina crowns(Procera) and, finally, eight on densely sintered zirconiacrowns (various CAD/CAM manufacturing procedures)(Table 1).
The studies included patients between the age of 17 and 81.The proportion of patients who could not be followed for thecomplete study period was available for 27 studies and rangedfrom 0% to 66% (Tables 1 and 2).
3.1.2. Excluded studiesDuring the full-text evaluation of the total of 41 single crownstudies, eight were excluded. Two articles (Ortorp et al.,2009; Walton et al., 2009) were multiple publications on the
same patient cohorts and were, therefore, excluded. Threemanuscripts (Mansour et al., 2008; Groten et al., 2010; Rinkeet al., 2011) reported on observation periods of less than 3years. One study (Cagidiaco et al., 2008) gave no detailed
d e n t a l m a t e r i a l s 3 1 ( 2 0 1 5 ) 603–623 611
First electronic search 580 Titles
+
and included studies on single crowns
Independently selected by 2 reviewers 71 titles
Agreed by both 71 titles
Abstracts obtained
DiscussionAgreed on 71 abstracts
Full text obtained
Total full text articles for “single crown review” 41
Final number of studies included 33
Furth er ha nd se arching 0 studies
Total full te xt articles for the “multiple- unit fixed dental
prosthesis” review 37
(number includes also s tudies repor ting on crowns and brid ges a t the same time )
Exclusion of 8 studies For de tails see reference list of excluded
literature
Total full te xt articles included from previous
single crowns” review[1] 34
= Total of included studies in present revi ew
67
clud
idraee
3Owrsc0vo(
vtews
frcgy((
m(y
Fig. 1 – Search strategy and in
nformation on crown material and did not report on theetails of the outcomes. In one study (Silva et al., 2011) theeported data was not specified between implant and toothbutments, single crowns and bridges. The last study (Burket al., 2009) was based on a chart review and, therefore, wasxcluded.
.1.3. Crown survivalverall, in the 17 studies reporting on metal-ceramic crownsith a mean follow-up of 7.3 years an estimated annual failure
ate of 0.88 was reported, translated into an estimated 5-yearurvival of metal-ceramic crowns of 95.7%. In comparison, all-eramic crowns had an annual failure rate ranging between.69 and 1.96, translating into overall estimated 5-year sur-ival rates ranging between 90.7% and 96.6%. This was basedn 55 studies on all-ceramic crowns included in the analysis
Table 3).The survival rates of all-ceramic crowns differed for the
arious types of ceramics. Ten studies reported on the firstypes of feldspathic/silica based ceramics and rendered anstimated 5-year survival rate of 90.7%. This survival rateas significantly lower than the one reported for the gold-
tandard, metal-ceramic crowns (Tables 3 and 4).The 12 studies reporting on leucit or lithium-disilicate rein-
orced glass ceramics showed an estimated 5-year survivalate of 96.6%, which was similar to the survival rate of metal-eramic crowns. The same applied for crowns made out oflass-infiltrated alumina (15 studies with an estimated 5-ear survival of 94.6%) and out of densely sintered aluminaeight studies with an estimated 5-year survival of 96.0%)Tables 3 and 4, Figs. 2–7).
SCs made out of zirconia had a significantly lower esti-ated 5-year survival rate compared to metal-ceramic crowns
p = 0.05). The zirconia-based crowns reached an estimated 5-ear survival rate of 91.2% (Tables 3 and 4, Fig. 7).
ed studies on single crowns.
3.1.4. Anterior vs. posterior regionsWhen the outcomes of anterior and posterior single crownswere compared no statistically significant differences of thesurvival rates were found for metal-ceramic crowns, and forleucit or lithium-disilicate reinforced glass ceramic crowns,alumina and zirconia based crowns (p > 0.05).
Crowns made out of feldspathic or silica based ceram-ics, however, exhibited significantly lower survival rates inthe posterior region than in the anterior (87.8% vs. 94.6%,p < 0.0001) (Table 5).
3.2. Technical and biological complications
Tables 6 and 7 display an overview of the incidences, theestimated annual complication rates and the cumulative com-plication rates of technical and biological complications formetal-ceramic SCs and the different types of all-ceramiccrowns, as well as the statistical differences between thecrown types.
3.2.1. Technical complicationsFramework fracture, ceramic fracture, ceramic chipping,marginal discoloration, loss of retention and poor estheticswere technical problems reported for single crowns.
Ceramic chipping was a common problem, and overalloccurred similarly for metal-ceramics and at the all-ceramic crowns. Furthermore, for metal-ceramic crowns,ceramic chipping was the most frequent technical compli-cation with a cumulative 5-year event rate of 2.6% (95%CI: 1.3–5.2%). For all-ceramic crowns a tendency to morechippings of the veneering ceramic was observed for alu-
mina and zirconia-based SCs than for all other ceramiccrowns.
Framework fracture rarely occurred for metal-ceramiccrowns (cumulative 5-year complication rate 0.03%; 95% CI
d e n t a l m a t e r i a l s 3 1 ( 2 0 1 5 ) 603–623 615
rate
0itocefo
Fig. 2 – Annual failure
.002– 0.3%) (Table 7). Overall, this problem occurred signif-cantly more often for ceramic crowns, irrespective of theype of ceramic used (p < .0001, p = .03) (Table 6). The incidencef framework fracture was associated with the mechani-al stability of the ceramic material. Weaker ceramics like
arly feldspathic/silica based ceramics exhibited a high 5-yearramework fracture rate of 6.7% (95% CI 2.4–17.7%). For leucitr lithium-disilicate reinforced glass ceramics framework
Fig. 3 – Annual failure rate
of metal ceramic SCs.
fractures occurred at a rate of 2.3% (95% CI 1.0–5.5%) of thecrowns and for zirconia-based single crowns at a rate of 0.4%only (95% CI 0.1–1.7%).
With the exception of zirconia-based crowns, loss of reten-tion was not a predominant technical problem. Zirconia based
crowns exhibited significantly more loss of retention thanmetal ceramic crowns (estimated 5-year complication rate4.7%; 95% CI 1.7–13.1%) (p < .0001) (Tables 6 and 7).
616 d e n t a l m a t e r i a l s 3 1 ( 2 0 1 5 ) 603–623
Fig. 4 – Annual failure rate of leucit or lithium-disilicate reinforced glass ceramic SCs.
3.2.2. Biological complicationsLoss of abutment tooth vitality, abutment tooth fracture andsecondary caries were the predominantly reported as biologiccomplications for SCs.
For metal-ceramic crowns loss of abutment tooth vitality
was the most frequent biologic complication (5-year com-plication rate 1.8%; 95% CI 1.6–1.8%). This problem lessfrequently occurred for leucit or lithium-disilicate reinforced
In addition, abutment tooth fracture was also predomi-nantly found for metal-ceramic crowns (5-year complicationrate 1.2%; 95% CI 0.7–2.0%). This complication occurred signif-
icantly less frequently for all-ceramics like leucit or lithiumdisilicate reinforced glass ceramics, glass infiltrated aluminaor at zirconia-ceramics (p = .009, p = .04, p = .02).
rates of all-ceramic crowns made out of leucit or lithium-disilicate reinforced glass ceramics or the oxide ceramics
Finally, secondary caries was reported for 1% of metal-eramic crowns (95% CI 0.8–1.4%) after 5 years in function.ost all-ceramic crowns exhibited similar 5-year caries
ates as metal-ceramic SCs. However, zirconia based crownsad significantly less secondary caries, and glass-infiltrated
eramic crowns had higher caries rates (p = .04, p < .0001)Tables 6 and 7).
Fig. 7 – Annual failure rate of densely
4. Discussion
The present systematic review showed that the 5-year survival
alumina and zirconia exhibited similar survival rates as thegold standard, metal ceramic crowns. This was not the case,
owever, for feldspathic/silica based ceramic SCs. Crownsade out of these rather weak ceramics exhibited significantly
igher failure rates compared to metal-ceramic crowns.The same observation was made when the outcomes of
he crowns in anterior and posterior regions were compared.etal-ceramic crowns and all-ceramic crowns out of leucit or
ithium-disilicate reinforced glass ceramics or oxide ceram-cs performed similarly in anterior and posterior regions.owever, weaker feldspathic/silica-based ceramics and glass-
nfiltrated alumina exhibited significantly lower survival ratesn the posterior region than in the anterior.
Technically, catastrophic framework fracture was the mainomplication of the all-ceramics, this problem was mostpecifically found when weaker ceramic materials were used12]. With respect to the non-catastrophic technical complica-ions, chipping of the veneering ceramic was a main clinicalssue both found at the metal-ceramic as well as at the all-eramic crowns [13]. Another technical problem observed wasoss of retention, which was most frequently reported forirconia-based single crowns [14].
Biologically, all-ceramic single crowns seemed to performetter than the gold standard, metal-ceramic crowns. Signif-
cantly more loss of abutment tooth vitality and abutmentooth fracture was reported for metal-ceramic crowns. Theseiologic complications might impair the prognosis of thebutment tooth or even lead to its loss and a loss of the recon-truction. In comparison, these complications were rarelyeported for the all-ceramic crowns.
At the time the previous systematic review was publishedy the same authors in 2007, limited scientific data was avail-ble in the literature on a number of materials. Still, theeview already indicated favorable outcomes of all-ceramicingle crowns made out of more recently developed reinforcederamics and oxide ceramics [1]. The review, furthermore, dis-layed limitations of mechanically weaker all ceramic crowns.he gold standard metal-ceramics, interestingly, was not wellocumented [1].
In the present review, 14 new studies on metal-ceramicsere available as well as a high number of new studies eval-ating all-ceramic crowns. The results of the present review,ence, may be considered more robust with more impact for
he daily clinical practice.In the present review it was shown that all-ceramic crowns
ade of leucit or lithium-disilicate reinforced glass ceram-cs or alumina based oxide ceramics can be recommended asn alternative treatment option to the gold standard metal-eramics for SCs in anterior and posterior regions. The lesstable feldspathic/silica glass ceramics can only be recom-ended in the anterior region.The review also indicated that zirconia based single crowns
erformed less well in the clinics, despite the enhancedechanical stability of this oxide ceramic. Failure due to
xtensive fracture of the veneering ceramic and loss of reten-ion were frequently found technical problems for this typef ceramic crowns, occurring more often than at the otherypes of all-ceramics. Chipping of the veneering ceramic and
oss of retention were technical complications also reportedor multiple-unit zirconia based FDPs [15–17], occurring sig-ificantly more often at the zirconia-based FDPs than atetal-ceramics [18]. The more recent clinical studies showed
( 2 0 1 5 ) 603–623 621
that despite all developments and efforts for the improve-ment of the veneering procedures of zirconia frameworks, theproblem of chipping of the zirconia veneering ceramic has notbeen eliminated yet [19,20]. Consequently, zirconia-based sin-gle crowns should not be considered as the primary treatmentoption for now, and patients need to be thoroughly informedabout current limitations.
Another factor influencing the choice of the material forsingle crowns in daily clinical practice is the biologic outcomeof the reconstructions. The present review indicated, that thebiological outcomes of all-ceramic crowns were significantlybetter than the ones of metal-ceramics. Less invasive abut-ment tooth preparation for the highly esthetic all-ceramicFDPs may be assumed as reason for the observed differences[21,22].
Considering the current trend toward less invasive den-tal rehabilitation, the biological differences between materialsmay be considered as one of the key decisive factors for thechoice of ceramics as reconstructive material for single crownstoday [21,22]. Future research should focus on this topic andalso further elucidate the reasons for the biologic differencesbetween all-ceramic and metal-ceramic reconstructions.
5. Conclusion
All-ceramic single crowns exhibit similar survival rates asmetal-ceramic single crowns after a mean observation periodof at least 3 years. However, this is solely true for SCs aremade out of leucit or lithium-disilicate reinforced glass ceram-ics or oxide ceramics. Those materials perform similarly wellin anterior and posterior regions. Crowns made out of denselysintered zirconia, however, cannot be recommended as pri-mary treatment option, due to an increased risk of chipping ofthe veneering ceramic and loss of retention. These limitationsmust first be overcome by further refinements of the produc-tion technology. Finally, the mechanically weaker ceramicslike the feldspathic or silica glass-ceramics can only be rec-ommended in anterior regions with low functional load.
Conflict of interest
The authors do report to have no conflict of interest.
Newly included further literature, as given inTables
[1] Pjetursson BE, Sailer I, Zwahlen M, Hammerle CH. Asystematic review of the survival and complication ratesof all-ceramic and metal-ceramic reconstructions after anobservation period of at least 3 years. Part I: Single crowns.Clinical oral implants research, 2007;18 Suppl. 3:73–85.[2] Sailer I, Pjetursson BE, Zwahlen M, Hammerle CH. Asystematic review of the survival and complication rates
of all-ceramic and metal-ceramic reconstructions after anobservation period of at least 3 years. Part II: Fixed dentalprostheses. Clinical oral implants research. 2007;18 Suppl3:86–96.
tional Journal of Computerized Dentistry. 14(3):203–18.
622 d e n t a l m a t e r i a
[3] Edelhoff D, Brix O. All-ceramic restorations in differentindications: a case series. Journal of the American DentalAssociation. 2011;142 Suppl 2:14S–9S.[4] Walton TR. Making sense of complication reportingassociated with fixed dental prostheses. The Internationaljournal of prosthodontics. 2014;27:114–8.[5] Raigrodski AJ, Chiche GJ, Potiket N, Hochstedler JL,Mohamed SE, Billiot S, et al. The efficacy of posterior three-unit zirconium-oxide-based ceramic fixed partial dentalprostheses: a prospective clinical pilot study. The Journal ofprosthetic dentistry. 2006;96:237–44.[6] Kirkwood BR, Sterne JAC. Medical Statistics, Chapter 24:Poisson Regression Oxford: Blackwell Science Ltd. 2003.[7] Kirkwood BR, Sterne JAC. Essential Medical Statis-tics, Chapter 26: Survival Analysis: Displaying and Com-paring Survival Patterns Oxford: Blackwell Science Ltd.2003.[8] Passia N, Stampf S, Strub JR. Five-year results of aprospective randomized controlled clinical trial of poste-rior computer-aided design-computer-aided manufacturingZrSiO4-ceramic crowns. Journal of oral rehabilitation.2013;40:609–17.[9] Cehreli MC, Kokat AM, Ozpay C, Karasoy D, AkcaK. A randomized controlled clinical trial of feldspathicversus glass-infiltrated alumina all-ceramic crowns: a 3-year follow-up. The International journal of prosthodontics.2011;24:77–84.[10] Naumann M, Ernst J, Reich S, Weisshaupt P, Beuer F.Galvano- vs. metal-ceramic crowns: up to 5-year results ofa randomized split-mouth study. Clinical oral investigations.2011;15:657–60.[11] Wolleb K, Sailer I, Thoma A, Menghini G, Hammerle CH.Clinical and radiographic evaluation of patients receivingboth tooth- and implant-supported prosthodontic treat-ment after 5 years of function. The International journal ofprosthodontics. 2012;25:252–9.[12] Malament KA, Socransky SS. Survival of Dicor glass-ceramic dental restorations over 20 years: Part IV. The effectsof combinations of variables. The International journal ofprosthodontics. 2010;23:134–40.[13] Ortorp A, Kihl ML, Carlsson GE. A 3-year retrospective andclinical follow-up study of zirconia single crowns performedin a private practice. J Dent. 2009;37:731–6.[14] Rinke S, Schafer S, Lange K, Gersdorff N, RoedigerM. Practice-based clinical evaluation of metal-ceramic andzirconia molar crowns: 3-year results. Journal of oral rehabil-itation. 2013;40:228–37.[15] Sax C, Hammerle CH, Sailer I. 10-year clinical out-comes of fixed dental prostheses with zirconia frameworks.International journal of computerized dentistry. 2011;14:183–202.[16] Sailer I, Gottnerb J, Kanelb S, Hammerle CH. Randomizedcontrolled clinical trial of zirconia-ceramic and metal-ceramic posterior fixed dental prostheses: a 3-year follow-up. The International journal of prosthodontics. 2009;22:553–60.[17] Schley JS, Heussen N, Reich S, Fischer J, Haselhuhn K,
Wolfart S. Survival probability of zirconia-based fixed dentalprostheses up to 5 yr: a systematic review of the literature.European journal of oral sciences. 2010;118:443–50.
1 ( 2 0 1 5 ) 603–623
[18] Heintze SD, Rousson V. Survival of zirconia- and metal-supported fixed dental prostheses: a systematic review. TheInternational journal of prosthodontics. 2010;23:493–502.[19] Gherlone E, Mandelli F, Cappare P, Pantaleo G, TrainiT, Ferrini F. A 3 years retrospective study of survival forzirconia-based single crowns fabricated from intraoral digitalimpressions. J Dent. 2014.[20] Koenig V, Vanheusden AJ, Le Goff SO, Mainjot AK.Clinical risk factors related to failures with zirconia-basedrestorations: an up to 9-year retrospective study. J Dent.2013;41:1164–74.[21] Edelhoff D, Sorensen JA. Tooth structure removal associ-ated with various preparation designs for anterior teeth. TheJournal of prosthetic dentistry. 2002;87:503–9.[22] Edelhoff D, Sorensen JA. Tooth structure removal associ-ated with various preparation designs for posterior teeth. IntJ Periodontics Restorative Dent. 2002;22:241–9.
List of excluded full-text articles and the reasonfor exclusion
[1] Mansour YF, Al-Omiri MK, Khader YS, Al-Wahadni A.(2008) Clinical performance of IPS-Empress 2 ceramic crownsinserted by general dental practitioners. The Journal of Con-temporary Dental Practice. 9(4):9–16. Exclusion criteria: meanfollow-up time < 3 years.[2]Cagidiaco MC, García-Godoy F, Vichi A, Grandini S, GoracciC, Ferrari M. (2008) Placement of fiber prefabricated or cus-tom made posts affects the 3-year survival of endodonticallytreated premolars. American Journal of Dentistry. 21(3):179–84.Exclusion criteria: no specific information on crown materialand no detailed outcomes.[3]Ortorp A, Kihl ML, Carlsson GE. (2009) A 3-year retro-spective and clinical follow-up study of zirconia singlecrowns performed in a private practice. Journal of Dentistry.37(9):731–6.Exclusion criteria: multiple publication of the same patientcohort.[4]Walton TR. (2009) Changes in the outcome of metal-ceramic tooth-supported single crowns and FDPs followingthe introduction of osseointegrated implant dentistry into aprosthodontic practice. The International Journal of Prosthodon-tics. 22(3):260–7.Exclusion criteria: multiple publication of the same patientcohort.[5]Burke FJ, Lucarotti PS. (2009) Ten-year outcome of crownsplaced within the General Dental Services in England andWales. Journal of Dentistry. 37(1):12–24.Exclusion criteria: based on a chart review.[6]Groten M, Huttig F. (2010) The performance of zirconiumdioxide crowns: a clinical follow-up. The International Journal ofProsthodontics. 23(5):429–31. Exclusion criteria: mean follow-up time < 3 years.[7]Rinke S, Schäfer S, Roediger M. (2011) Complication rate ofmolar crowns: a practice-based clinical evaluation. Interna-
Exclusion criteria: mean follow-up time < 3 years.[8]Silva NR, Thompson VP, Valverde GB, Coelho PG, Pow-ers JM, Farah JW, Esquivel-Upshaw J. (2011) Comparative
reliability analyses of zirconium oxide and lithium disilicaterestorations in vitro and in vivo. Journal of the American DentalAssociation (1939). 142 Suppl 2:4S–9S.Exclusion criteria: data not specified between implant andtooth abutments, single crowns and bridges.
e f e r e n c e s
[1] Pjetursson BE, Sailer I, Zwahlen M, Hammerle CH. Asystematic review of the survival and complication rates ofall-ceramic and metal-ceramic reconstructions after anobservation period of at least 3 years. Part I: Single crowns.Clin Oral Implants Res 2007;18(Suppl. 3):73–85.
[2] Sailer I, Pjetursson BE, Zwahlen M, Hammerle CH. Asystematic review of the survival and complication rates ofall-ceramic and metal-ceramic reconstructions after anobservation period of at least 3 years. Part II: Fixed dentalprostheses. Clin Oral Implants Res 2007;18(Suppl. 3):86–96.
[3] Edelhoff D, Brix O. All-ceramic restorations in differentindications: a case series. J Am Dent Assoc 2011;142(Suppl.2):14S–9S.
[4] Walton TR. Making sense of complication reportingassociated with fixed dental prostheses. Int J Prosthodont2014;27:114–8.
[5] Raigrodski AJ, Chiche GJ, Potiket N, Hochstedler JL,Mohamed SE, Billiot S, et al. The efficacy of posteriorthree-unit zirconium-oxide-based ceramic fixed partialdental prostheses: a prospective clinical pilot study. JProsthet Dent 2006;96:237–44.
[9] Cehreli MC, Kokat AM, Ozpay C, Karasoy D, Akca K. Arandomized controlled clinical trial of feldspathic versusglass-infiltrated alumina all-ceramic crowns: a 3-yearfollow-up. Int J Prosthodont 2011;24:77–84.
[10] Naumann M, Ernst J, Reich S, Weisshaupt P, Beuer F.Galvano- vs. metal-ceramic crowns: up to 5-year results of arandomised split-mouth study. Clin Oral Investig2011;15:657–60.
[11] Sax C, Hammerle CH, Sailer I. 10-year clinical outcomes offixed dental prostheses with zirconia frameworks. Int JComput Dent 2011;14:183–202.
[12] Sailer I, Gottnerb J, Kanelb S, Hammerle CH. Randomizedcontrolled clinical trial of zirconia-ceramic andmetal-ceramic posterior fixed dental prostheses: a 3-yearfollow-up. Int J Prosthodont 2009;22:553–60.
[13] Schley JS, Heussen N, Reich S, Fischer J, Haselhuhn K,Wolfart S. Survival probability of zirconia-based fixed dentalprostheses up to 5 yr: a systematic review of the literature.Eur J Oral Sci 2010;118:443–50.
[14] Heintze SD, Rousson V. Survival of zirconia- andmetal-supported fixed dental prostheses: a systematicreview. Int J Prosthodont 2010;23:493–502.
[15] Gherlone E, Mandelli F, Cappare P, Pantaleo G, Traini T,Ferrini F. A 3 years retrospective study of survival forzirconia-based single crowns fabricated from intraoraldigital impressions. J Dent 2014;49(9):1151–5.
[16] Koenig V, Vanheusden AJ, Le Goff SO, Mainjot AK. Clinicalrisk factors related to failures with zirconia-basedrestorations: an up to 9-year retrospective study. J Dent2013;41:1164–74.
[17] Edelhoff D, Sorensen JA. Tooth structure removal associatedwith various preparation designs for anterior teeth. J
Prosthet Dent 2002;87:503–9.
[18] Edelhoff D, Sorensen JA. Tooth structure removal associatedwith various preparation designs for posterior teeth. Int JPeriodont Restor Dent 2002;22:241–9.