The clinical performance of ceramic inlays: a review

Clinical Behavior of Ceramic, Hybrid and Composite Onlays. A Systematic Review and Meta-Analysis

A systematic review and meta-analysis was performed to analyze the survival of onlay restorations in the posterior region, their clinical behavior according to the material used (ceramic reinforced with lithium disilicate, conventional feldspathic ceramic or reinforced with leucite; hybrid materials and composite), possible complications, and the factors influencing restoration success. The systematic review was based on the preferred reporting items for systematic reviews and meta-analyses (PRISMA) statement, without publication date or language restrictions. An electronic search was made in the PubMed, Scopus, Embase, and Cochrane databases. After discarding duplicate publications and studies that failed to meet the inclusion criteria, the articles were selected based on the population, intervention, comparison, outcome (PICO) question. The following variables were considered in the qualitative and quantitative analyses: restoration survival rate (determined by several clinical parameters), the influence of the material used upon the clinical behavior of the restorations, and the complications recorded over follow-up. A total of 29 articles were selected for the qualitative analysis and 27 for the quantitative analysis. The estimated restoration survival rate was 94.2%. The predictors of survival were the duration of follow-up (beta = −0.001; p = 0.001) and the onlay material used (beta = −0.064; p = 0.028). Composite onlays were associated with a lower survival rate over time. Onlays are a good, conservative, and predictable option for restoring dental defects in the posterior region, with a survival rate of over 90%. The survival rate decreases over time and with the use of composite as onlay material.

Evaluation of fracture resistance and mode of failure of premolars restored with nanohybrid composite, ORMOCER and ceramic inlays

Objectives

To evaluate the fracture resistance and mode of failure of maxillary premolars restorations restored with nanohybrid Composite, ORMOCER and Ceramic Inlays.

Materials and method

100 extracted first maxillary premolar were collected. Samples were divided into five groups. Group I - Intact premolars, Group II -MOD cavities without restorations, Group III - MOD cavities restored with composite restoration, GROUP IV - MOD cavities restored with ORMOCER restoration and GROUP V - MOD cavities restored with ceramic inlays. All the samples were sent for the axial compression test under the universal testing machine. Fracture resistance and fracture modes were recorded.

Result

Highest fracture resistance was achieved in Group V (1324.74 ± 336.78) almost comparable to that of natural tooth (1381.07 ± 259.36) (p < 0.05), followed by Group IV (MOD cavities with ORMOCER restorations) (1082.27 ± 351.27) (p < 0.01) and least fracture resistance in Group III (MOD cavities with composite restorations) (778.35 ± 100.25) (p < 0.0001). Mode of fracture in Group IV and Group V are almost similar and In Group III 65% of the cases showed non-restorable fractures.

Conclusion

ORMOCER fracture resistance along with other groups of clinically restorable fracture stand better than Nanohybrid composite.

Clinical Relevance

Based on the present study, the dentist can utilize the ORMOCER material as a restoration material for the cavities of posterior teeth which is better in terms of fracture resistance and durability of the restoration when compare to nanohybrid composite.

Effect of immediate dentine sealing on the fracture strength of lithium disilicate and multiphase resin composite inlay restorations

PURPOSE

Limited information is available on the effect of Immediate Dentin Sealing (IDS) on the fracture strength of indirect partial posterior restorations. This study evaluated the effect of IDS on the fracture strength and failure types of two indirect restorative materials.

MATERIALS AND METHODS

Standard MOD inlay preparations were made on sound molars (N=40, n=10 per group) and randomly divided into four groups to receive the inlay materials with and without the application of IDS: Group L-IDS-: Li₂Si₂O₅ (Lithium disilicate, IPS e.max) without IDS; Group L-IDS+: Li₂Si₂O₅ with IDS; Group MR-IDS-: Multiphase resin composite (MR, Lava Ultimate) without IDS; MR-IDS+: MR with IDS. Inlays made of L were etched with 5% hydrofluoric acid, and MR inlays were silica coated. After silanization, they were cemented using adhesive resin cement (Variolink Esthetic DC). The specimens were thermo-mechanically aged (1.2×10⁶ cycles, 1.7Hz, 8000 cycles, 5-55°C) and then subjected to load to failure (1 mm/min). Failure types and locations of debondings were classified. Data were statistically analyzed using ANOVA, Mann Whitney U-test and Chi-square tests (α=0.05). Two-parameter Weibull distribution values including the Weibull modulus, scale (m) and shape (0), values were calculated.

RESULTS

After aging conditions, no apparent changes were observed in marginal integrity but occlusal wear facets were more common with MR than with L (p<0.001). Material type and the application of IDS significantly affected the results (p=0.013). While group L-IDS- showed the lowest mean fracture strength (1358±506N) among all groups (p<0.05), application of IDS significantly increased the results significantly (L-IDS+: 2035±403N) (p=0.006). MR groups with and without IDS, did not show significant difference (MR-IDS-: 1861±423, MR-IDS+: 1702±596 N) (p=0.498). When materials without IDS are compared, L showed significantly lower results than that of MR (p=0.035). With the application of IDS, no significant difference was noted between L and MR materials (p=0.160). Weibull distribution presented the highest shape (0) for L-IDS+ (5.66) compared to those of other groups (3.01-4.76). Neither the material type (p=0.830), nor the application of IDS (p=0.54) affected the severity of the failure types. In 95% of the cases, the IDS layer left adhered on the tooth surface after fracture tests. In groups where no IDS was used, resin cement remained on the tooth surface in 44% of the cases (p=0.001). No significant differences were observed between the materials with respect to cement remnants or IDS after fracture (p=0.880). The incidence of repairable failure types (83%) was more common with L than with MR (75%) material (p>0.05).

CONCLUSION

Immediate dentin sealing improves adhesion, and thereby the fracture strength of inlays made of lithium disilicate but not that multiphase resin composite.

Shear bond, wettability and AFM evaluations on CO2 laser-irradiated CAD/CAM ceramic surfaces

The purpose of this study is to determine the CO₂ laser irradiation in comparison with sandblasting (Sb), hydrofluoric acid (Hf) and silane coupling agent (Si) on shear bond strength (SBS), roughness (Rg) and wettability (Wt) of resin cement to CAD/CAM ceramics. Sixty (CAD/CAM) ceramic discs were prepared and distributed into six different groups: group A, control lithium disilicate (Li); group B, control zirconia (Zr); group C, Li: CO₂/HF/Si; group D, Li: HF/Si; group E, Zr: CO₂/Sb/Si; group F, Zr: Sb/Si. Result showed significant difference between irradiated and non-irradiated in terms of shear bond strength for zirconia ceramics (p value = 0.014). Moreover, partial surface wettability for irradiated and non-irradiated ceramics. Irradiated surface demonstrated more rough surface in lithium disilicate than zirconia ceramics. CO₂ irradiation could increase shear bond strength, surface roughness and wettability for both CAD/CAM ceramics.

WITHDRAWN: Ceramic inlays for restoring posterior teeth

Withdrawn as the review has been superseded by a more up to date version of a Cochrane review of the same title.

The editorial group responsible for this previously published document have withdrawn it from publication.

Shear bond strength of resin cement to an acid etched and a laser irradiated ceramic surface

PURPOSE

To evaluate the effects of hydrofluoric acid etching and Er,Cr:YSGG laser irradiation on the shear bond strength of resin cement to lithium disilicate ceramic.

MATERIALS AND METHODS

Fifty-five ceramic blocks (5 mm × 5 mm × 2 mm) were fabricated and embedded in acrylic resin. Their surfaces were finished with 1000-grit silicon carbide paper. The blocks were assigned to five groups: 1) 9.5% hydrofluoric-acid etching for 60 s; 2-4), 1.5-, 2.5-, and 6-W Er,Cr:YSGG laser applications for 60 seconds, respectively; and 5) no treatment (control). One specimen from each group was examined using scanning electron microscopy. Ceramic primer (Rely X ceramic primer) and adhesive (Adper Single Bond) were applied to the ceramic surfaces, followed by resin cement to bond the composite cylinders, and light curing. Bonded specimens were stored in distilled water at 37℃ for 24 hours. Shear bond strengths were determined by a universal testing machine at 1 mm/min crosshead speed. Data were analyzed using Kruskal-Wallis and Mann-Whitney U-tests (α=0.05).

RESULTS

Adhesion was significantly stronger in Group 2 (3.88 ± 1.94 MPa) and Group 3 (3.65 ± 1.87 MPa) than in Control group (1.95 ± 1.06 MPa), in which bonding values were lowest (P<.01). No significant difference was observed between Group 4 (3.59 ± 1.19 MPa) and Control group. Shear bond strength was highest in Group 1 (8.42 ± 1.86 MPa; P<.01).

CONCLUSION

Er,Cr:YSGG laser irradiation at 1.5 and 2.5 W increased shear bond strengths between ceramic and resin cement compared with untreated ceramic surfaces. Irradiation at 6 W may not be an efficient ceramic surface treatment technique.

Considerations for ceramic inlays in posterior teeth: a review

This review of ceramic inlays in posterior teeth includes a review of the history of ceramic restorations, followed by common indications and contraindications for their use. A discussion on the potential for tooth wear is followed by a review of recommended preparation design considerations, fabrication methods, and material choices. Despite the improved materials available for fabrication of porcelain inlays, fracture remains a primary mode of inlay failure. Therefore, a brief discussion on strengthening methods for ceramics is included. The review concludes with a section on luting considerations, and offers the clinician specific recommendations for luting procedures. In conclusion, inlay success rates and longevity, as reported in the literature, are summarized.

Novel glass-ceramics for dental restorations

BACKGROUND

There are many different ceramic systems available on the market for dental restorations. Glass-ceramics are a popular choice due to their excellent esthetics and ability to bond to tooth structure allowing a more conservative approach. However, at present, these materials have insufficient strength to be used reliably in posterior regions of the mouth.

PURPOSE

The aim of this review article is to discuss the types of novel glass-ceramic currently be investigated including composition, microstructure and properties.

CONCLUSION

Current research in glass-ceramics focuses on the quest for a highly esthetic material along with sufficient strength to enable crowns and bridgework to be reliably placed in these areas.

CLINICAL SIGNIFICANCE

There is a gap in the market for a machinable resin bonded glass-ceramic with sufficient strength as well as excellent esthetics.

Two-year Clinical Evaluation of IPS Empress II Ceramic Onlays/Inlays

The two-year success rate of restorations reported in the current study demonstrates that IPS Empress II ceramics are clinically acceptable for onlay/inlay restorations on molars.

The clinical success of all-ceramic restorations

BACKGROUND

The authors conducted a comprehensive literature review to compile and compare clinical evidence for the treatment of teeth using all-ceramic restorations.

TYPES OF STUDIES REVIEWED

The authors searched the English-language peer-reviewed literature using MEDLINE and PubMed with a focus on research published between 1993 and 2008. They also conducted a hand search of relevant dental journals. They reviewed randomized controlled trials, nonrandomized controlled studies, longitudinal experimental clinical studies, longitudinal prospective studies and longitudinal retrospective studies.

RESULTS

Evidence suggests that for veneers, intracoronal restorations and complete-coverage restorations for single-rooted anterior teeth, clinicians may choose from any all-ceramic system on the basis of esthetic needs (many systems have had greater than 90 percent success at six years). Well-studied molar restorations include those made of alumina and, increasingly, zirconia and bonded lithium disilicate. Reasonable evidence has shown the effectiveness of anterior three-unit fixed partial dentures made of lithium disilicate, alumina and zirconia. For three-unit restorations involving a molar, expert consensus suggests that only zirconia-based systems are indicated.

CLINICAL IMPLICATIONS

Available evidence indicates the effectiveness of many all-ceramic systems for numerous clinical applications. Bonding has been shown to increase clinical success. Studies of zirconia prostheses indicate problems with porcelain cracking.

Shear bond strength between feldspathic CAD/CAM ceramic and human dentine for two adhesive cements

PURPOSE

The purpose of this study was to evaluate the shear bond strength values between dentin substrate and a feldspathic ceramic material, based on computer-assisted design and manufacture (CAD/CAM) technology, bonded together with two adhesive systems coupled with two dual-polymerized luting agents. In addition, the effect of a silane coupling agent on bond strength was evaluated.

MATERIAL AND METHODS

Forty cylinders (6 mm in diameter, 5 mm thick) obtained from feldspathic ceramic blocks were cemented to the dentin of 40 recently extracted human teeth stored in saline solution at room temperature until testing. The specimens were randomly divided into four groups of ten teeth each. All specimens were airborne-particle abraded and etched with hydrofluoric acid. In the first two groups (A1, A2) 20 ceramic cylinders were cemented using Excite DSC and Variolink II; in the A2 group the bonding surfaces were also treated with a silane coupling agent. In Groups B1 and B2, 20 ceramic cylinders were cemented using Scotchbond MPP and RelyX ARC; in the B2 group the bonding surfaces were also treated with a silane coupling agent as in Group A2. All cemented specimens were submitted to a shear bond strength test to check the strength of adhesion between the two substrates, dentin and ceramic. The data were analyzed with two-way analysis of variance (p < 0.05).

RESULTS

The mean values of the shear bond strength were (in MPa): 22 +/- 7 for Excite DSC/Variolink II without silanization (Group A1); 29 +/- 3 for Excite DSC/Variolink II with silanization (Group A2); 22 +/- 4 for Scotchbond MPP/RelyX ARC without silanization (Group B1); and 26 +/- 5 for Scotchbond MPP/RelyX ARC with silanization (Group B2). Two-way ANOVA revealed a significant effect of silanization (p < 0.01) and did not reveal any significant effect for either the bonding agents (p > 0.1) or the interaction between silanization and bonding agent (p > 0.05). Multinomial logit model did not show any statistical effects on the failure mode by the shear bond strength (p > 0.1). The hypotheses of independence between failure mode (cohesive vs. adhesive) and both the adhesive system (p < 0.05) and silanization (p < 0.05) were rejected by Pearson's chi-square test.

CONCLUSION

Within the assumptions and limitations of this study (including the small number of specimens) both bonding systems used achieved good shear bond strength values. The application of a silane coupling agent on the ceramic surface after etching with hydrofluoric acid increased the adhesion strength with both adhesive materials used.

Survival of Inlays and Partial Crowns Made of IPS Empress After a 10-year Observation Period and in Relation to Various Treatment Parameters

Ceramic inlays as aesthetic restorations in the posterior region can be used successfully in routine clinical therapy. Cement viscosity, the operator (experienced dentist vs dental student) and the number of surfaces have no influence on longevity.

The Effect of Base Materials with Different Elastic Moduli on the Fracture Loads of Machinable Ceramic Inlays

Based on the results of this study, the elastic moduli of base materials had an influence on fracture loads of machinable ceramic inlays. The use of a base material with a high elastic modulus to support a ceramic inlay is recommended.

Survival of resin-bonded porcelain veneer crowns placed with and without metal reinforcement

OBJECTIVES

The purpose of this retrospective case study of dental records was to compare the long-term failure rates and modes for resin-bonded sintered feldspathic porcelain veneer crowns (RBPVCs) either containing or without metal substructure reinforcement.

METHODS

Two prosthodontists placed 62 RBPVCs fabricated with, and 167 without, metal reinforcement in 143 older adolescent and adult patients treated in a private practice. Clinical judgement determined the type of crown design placed. Preparation margins were generally finished on enamel, and all crowns occluded with opposing teeth. Observations included the patients, operators, crown designs and failure modes. Chi-square or Fisher's exact tests and life table survival statistics were used to evaluate the findings (alpha = 0.05).

RESULTS

Over five years, failures occurred in 14.5% of RBPVCs fabricated with, and in 18.6% without, metal reinforcement. Cumulative survival estimates were 74.3 +/- 8.5(Standard Error)% and 72.9 +/- 4.8(SE)%, respectively (P = 0.96). Mandibular posterior crowns comprised 27.1% of the placements, but 47.5% of the failures. Bulk fracture of porcelain occurred in 7.0% of the crowns, all without metal reinforcement. Minor porcelain fractures and debonding were less frequent in both types of crowns. Persistent pulpitis occurred in 3.5% of all teeth.

CONCLUSIONS

There was a significant risk of failure for sintered porcelain RBPVCs placed as posterior restorations. Although metal reinforcement was able to reduce the risk of bulk fracture of porcelain, other causes of failure were less affected.

Marginal toughness of bonded dental ceramics evaluated by determination of the crack length

OBJECTIVES

The objective of this study was to evaluate the toughness of dental ceramics near a bonded interface using indentation microfracture.

METHODS

The ceramics used in the present study were two leucite-reinforced ceramics (IPS Empress and Finesse), one lithia-based ceramic (IPS Empress 2) and one mica-based ceramic (OCC). The ceramic discs were processed according to the manufacturers instructions and were bonded to resinous discs using a resin composite cement. The bonded specimens were sectioned perpendicularly, and micro-Vickers indentations were imprinted at several distances from the bonded interface in the polished ceramic sections. The lengths between the two ends of the radial cracks along the bonded interface were measured.

RESULTS

Crack lengthening was recognized when the distance was within 70 microm. In each ceramic, the indentation crack length at 40 microm from the interface was significantly longer than the length at the inner point of the ceramic material (p<0.05). The order of the mean indentation crack lengths at 40 microm was OCC>Finesse>IPS Empress 2>IPS Empress, while the order at 490 microm was Finesse>OCC>IPS Empress>IPS Empress 2. There was a difference between the orders at 40 microm and at 490 microm.

SIGNIFICANCE

The behaviour of the indentation crack near the interface differs from that which is distant from the interface. Therefore, it is impossible to estimate the marginal toughness of the ceramic based on the indentation microfracture at the inner point of the ceramic.

Ceramic inlays bonded with two adhesives after 4 years

OBJECTIVE

The aim of the present study was to clinically evaluate the effect of two different adhesive/resin composite combinations for luting of IPS Empress inlays.

METHODS

Ninety-four IPS Empress restorations were placed in 31 patients in a controlled prospective clinical split-mouth study. The restorations were luted with EBS Multi/Compolute (3M Espe) or with Syntac/Variolink II low (Ivoclar Vivadent) without lining. At baseline and after 0.5, 1, 2, and 4 years, the ceramic restorations were examined according to modified USPHS codes and criteria.

RESULTS

Two patients including four restorations missed the 4 years recall (drop out). After 4 years of clinical service, four restorations in two patients (three luted with Compolute, one with Variolink II) had to be replaced due to hypersensitivities, 90 inlays and onlays were acceptable (failure rate 4%; Kaplan-Meier survival analysis). Between the five recalls, a statistically significant deterioration was found for the criteria marginal adaptation and inlay fracture (Friedman 2-way ANOVA; p < 0.05). Between the adhesives no statistical difference was found. At baseline, 95% of the restorations revealed luting composite overhangs. After 4 years, 55% of cases had overhangs and 38% showed marginal ditching. No differences were found for surface roughness, color matching, integrity tooth, proximal contact, hypersensitivity, and satisfaction (p > 0.05).

CONCLUSION

For luting of ceramic inlays, no difference between the two luting systems was detectable. The overall failure rate after 4 years was 4%.

Technology assessment in dentistry: A comparison of the longevity and cost-effectiveness of inlays

Objectives: An example of technology assessment in dental care by evaluating the (cost-)effectiveness of types of three-surface inlays (gold, laboratory-fabricated ceramic, and chairside CAD/CAM ceramic) is provided.

Methods: MEDLINE, EMBASE, and the Cochrane Library were searched for studies published between 1966 and June 2003 that reported annual survival probabilities and annual observations. The longevity of different types of inlays was measured by the number of failure-free years. Annual survival rates from different studies were pooled by weighing the rates of each study by the inverse of the variance of the effect estimate. A cost-effectiveness analysis from the perspective of German private health insurers was performed using billing charges.

Results: Three, five, and two case series on laboratory-fabricated ceramic, chairside CAD/CAM ceramic, and gold inlays, respectively, were included. Over a 9-year observation period, the number of undiscounted failure-free years was 8.62 (95 percent confidence interval, 8.40–8.85), 8.65 (8.58–8.73), and 8.76 (8.72–8.80) for laboratory-fabricated ceramic, chairside CAD/CAM ceramic, and gold inlays, respectively. Laboratory-fabricated ceramic inlays were the most expensive.

Conclusions: While laboratory-fabricated ceramic, chairside CAD/CAM ceramic, and gold inlays had a strikingly similar failure-free survival rate, laboratory-fabricated ceramic inlays had the highest costs and, thus, were less cost-effective than chairside CAD/CAM ceramic and gold inlays.

Survival of ceramic onlays placed with and without metal reinforcement

STATEMENT OF PROBLEM

All-ceramic molar onlays continue to have higher failures from bulk fracture than similar cast metal onlays.

PURPOSE

The purpose of this retrospective study was to compare long-term failure rates and causes for posterior sintered feldspathic ceramic (Mirage) onlays placed with and without metal substructure reinforcement.

MATERIAL AND METHODS

Nineteen onlays were placed with and 78 without metal reinforcement in 50 older adolescent and adult patients treated by 2 prosthodontists in a private practice. All onlays opposed occluding tooth surfaces. Clinical judgment determined the type of onlay placed. Observational factors included patients, clinicians, onlay sites, and failure modes. Acrylic resin maxillary splints were generally provided for patients with multiple onlays or parafunctional habits. Thirty-six dies were also available for comparison of the occlusal thickness and taper of intact and failed molar onlays. The chi-square test or Fisher exact test, Student t test, and life table survival statistics were used to evaluate the data (alpha=.05).

RESULTS

Over 6 years, failures occurred in 21.1% of onlays placed with metal reinforcement and in 26.9% without metal reinforcement. Cumulative survival estimates (+/- standard error) were 62.4% +/- 14.7% and 60.5% +/- 6.3%, respectively (P=.84). Bulk fracture occurred in 16.5% of molars, independent of metal reinforcement (P=1.00). Overall, 11.4% of premolar and 33.9% of molar onlays failed. Irreversible pulpitis occurred in 6.2% of all teeth. From the dies, there were no clear relationships between either the thickness of occlusal ceramic material or the internal preparation taper and molar onlay failures, for onlays placed with or without metal reinforcement.

CONCLUSION

Sintered ceramic onlays placed with and without metal reinforcement showed a similar incidence of bulk fracture in molars. Preparations for both types of onlays were similar.

Dental ceramics: current thinking and trends

Dental ceramics are presented within a simplifying framework allowing for understanding of their composition and development. The meaning of strength and details of the fracture process are explored, and recommendations are given regarding making structural comparisons among ceramics. Assessment of clinical survival data is dealt with, and literature is reviewed on the clinical behavior of metal-ceramic and all-ceramic systems. Practical aspects are presented regarding the choice and use of dental ceramics.

RETROSPECTIVE CLINICAL EVALUATION OF 1,314 CAST GOLD RESTORATIONS IN SERVICE FROM 1 TO 52 YEARS

A retrospective clinical evaluation of 1,314 cast gold restorations in 114 patients placed by one practitioner was conducted. A very high percentage of patients contacted (114/116 [98.3%]) participated in the evaluation. Almost 90% of the restorations had been in service for over 9 years, 72% for over 20 years, and 45% from 25 to 52 years. All restorations had been cemented using zinc phosphate cement. The restorations were evaluated by independent evaluators in terms of marginal integrity, anatomic form, and surface texture, and 96% of the evaluations were excellent (Figures 1-5). Sixty restorations required removal and replacement, yielding an overall failure rate of 4.6% or a survival rate of 95.4%. The survival rates at various time periods were 97% at 9 years, 90.3% at 20 years, 94.9% at 25 years, 98% at 29 years, 96.9% at 39 years, and 94.1% for restorations in place > 40 years. It appears that properly fabricated cast gold inlays, onlays, partial veneer crowns, and full veneer crowns can provide extremely predictable, long-term restorative service. It is suggested that the use of such restorations should not be automatically precluded simply because they are gold colored. These restorations should be considered in patients who are more concerned with longevity than esthetics, and in those patients in whom placement of a conservative cast gold restoration would not result in an unesthetic display of metal.

Ceramic inlays for restoring posterior teeth

BACKGROUND

In recent decades ceramic inlays have been used with the increasing requirements from patients for tooth-coloured restorations in posterior teeth. Ceramic inlays can offer an excellent appearance, however, their long-term prognosis is uncertain, as only a few studies have reported the long-term clinical performance of these restorations.

OBJECTIVES

To compare the effectiveness of ceramic inlays in posterior teeth with other posterior restorations.

SEARCH STRATEGY

We conducted an electronic search of the Cochrane Oral Health Group Trials Register, the Cochrane Central Register of Controlled Trials ( The Cochrane Library Issue 1, 2002), MEDLINE, and EMBASE from 1990 to 2001. Handsearching included relevant journals and bibliographies of all relevant papers and review articles from 1990 up to 2001. In addition, we contacted experts and companies conducting clinical research on ceramic restorations to find other trials or unpublished materials or to clarify ambiguous or missing data.

SELECTION CRITERIA

Randomized controlled trials, in which the longevity of ceramic inlays is compared with those of other posterior restorations.

DATA COLLECTION AND ANALYSIS

Screening of possible studies and data extraction were independently conducted by two reviewers (MH and AY) using a specially designed chart. Authors of studies were contacted for additional information. The methodological quality of studies was assessed in duplicate using individual components. The Cochrane Oral Health Group statistical guidelines were followed and the results expressed as Odds Ratio (OR) and 95% confidence interval for dichotomous outcomes.

MAIN RESULTS

Two studies fulfilled the criteria to be included in the review. However, one of them was later excluded from the review, as the study design was not clearly described. The remaining, included study, evaluated the clinical performance of 60 ceramic inlays and 20 gold inlays for five years. Seven of the 60 ceramic inlays and two of the 20 gold inlays failed at five-year review. No ceramic inlays resulted in postoperative pain/discomfort after the treatment, however, one gold inlay did. The power of the included study was not great enough to detect an important difference in longevity and postoperative pain/discomfort between ceramic and gold inlays.

REVIEWER'S CONCLUSIONS

There is no strong evidence available to support any differences in the clinical performance of ceramic inlays and other posterior restorations. There is a limited number of well-designed clinical trials within this research area. Greater attention to the design and reporting of studies should be given to improve the study quality of ceramic restoration trials.

Partial-coverage posterior ceramic restorations. Part 1: a return to diligence

The application of multisurfaced tooth-colored restorations in the posterior dentition is an exercise in risk tolerance when dentin occupies the bulk of the tooth substrate. Not only is interfacial integrity capricious, but also a recent in vivo study has confirmed that dentin bond strengths deteriorate with time. Although the literature is replete with esthetic guidelines for posterior restitution, most practicing clinicians appreciate the prime tenet that clinical success involves more than esthetic realism in the posterior dentition. Success with indirect ceramic restorations is dependent on interfacial integrity, which, although multitudinous, is contingently related to operative competence. Innovative clinical techniques are described in this two-part article, along with a discussion of the probationary status of current adhesive options and the need for excellence in all phases of this demanding restorative sequence.

CLINICAL SIGNIFICANCE

Restorative success in the posterior dentition is profoundly influenced by the variability of operative competence and diligence. This article discusses the precincts of posterior indirect ceramic restorations and submits a number of innovative solutions to the clinical challenge.