STATEMENT OF PROBLEM: The clinical performance and failure mechanisms of recently introduced ceramic crown systems used to restore posterior teeth have not been adequately examined. PURPOSE: The purpose of this prospective clinical study was to evaluate and compare the clinical performance of 2 new ceramic crown systems with that of metal ceramic crowns using modified United States Public Health Services (USPHS) criteria. MATERIAL AND METHODS: Ninety posterior teeth requiring crown restorations in 48 patients were randomized into 3 equal groups (n=30) for which different crown systems were used: an experimental hot-pressed glass ceramic based on a modified lithium disilicate ceramic (IPS e.max Press), an alumina-coping-based ceramic (Procera AllCeram), and a metal ceramic (Simidur S 2 veneered with IPS Classic Porcelain). The crowns were assessed over 3 years using the modified USPHS criteria. Crowns that developed visible cracks were sectioned and removed, and the surfaces were analyzed using a scanning electron microscope (SEM). The data were analyzed using the Kruskal-Wallis nonparametric statistical test, followed by the Mann-Whitney test with Bonferroni correction (alpha=.05). RESULTS: USPHS evaluation showed that the IPS e.max Press and metal ceramic crowns experienced fewer clinical changes than Procera AllCeram. Visible roughness, wear, and deformity were noticed in occlusal contact areas of Procera AllCeram crowns. SEM images showed well defined wear facets in both ceramic crown systems. Kruskal-Wallis tests showed a significant difference (P<.05) in Alpha scores among the 3 crown systems. Mann-Whitney tests showed significant differences among groups. CONCLUSIONS: IPS e.max Press crowns demonstrated clinical behavior comparable to Procera AllCeram and metal ceramic crowns, but the wear resistance of this crown type was superior to the Procera AllCeram crowns, according to modified USPHS criteria.

PURPOSE To evaluate the effect of different strategies for post cementation on the pullout bond strength of a double-tapered glass fiber post cemented into a root canal. Materials and METHODS The root canals of 70 single-rooted bovine teeth (16 mm-length) were prepared to 9 mm using the preparation drill of a double-tapered glass fiber post system (White Post DC, FGM). Each specimen was embedded in a plastic cylinder using acrylic resin up to 3 mm of the most coronal portion of the specimen and allocated into one of seven groups (n=10) based on strategies for cementation: Gr1-ScotchBond Multi Purpose plus (SBMP)+ Relyx ARC resin cement; Gr2-Single Bond + Relyx ARC; Gr3-ED Primer + Panavia F resin cement; Gr4-SBMP + AllCem resin cement; Gr5-Relyx ARC; Gr6-Relyx Unicem resin cement; Gr7-Relyx Luting 2 glass ionomer cement. After cementation, the specimens were stored for seven days (in a humid environment at 37 degrees C) and submitted to pullout bond strength testing (the inferior part of each specimen was fixed and the fiber post was pulled out). The data (Kgf) were submitted to statistical analysis (one-way ANOVA and post-hoc Tukey tests, alpha=.05). The tested specimens were analyzed under the microscope and SEM for fracture analysis. RESULTS The strategy for post cementation affected the pullout retentive strength (Kgf)(p<0.0001) significantly. Gr6 (37.7 +/- 8a), Gr1 (37.4 +/- 5.7a) and Gr4 (31.6 +/- 6.6ab) presented the highest pullout bond strengths. Gr2 (12.2 +/- 5.6c), Gr3 (6.5 +/- 5.2c) and Gr7 (5.1 +/- 2.8c) presented the lowest pullout bond strengths. Gr5 (24.2 +/- 7.4b) was similar to Gr4 and inferior to Gr6 and Gr1. CONCLUSION The use of a three-step etch-&-rinse adhesive system appears to be effective. The application of other adhesive systems (single-bottle etch-&-rinse and self-etch adhesive systems) did not present high pullout strength values. The simplified self-adhesive resin cement (without adhesive application) presented good retentive performance. Further studies should be conducted.

OBJECTIVES To compare and evaluate effects of CO(2) laser and conventional surface treatments on surface roughness and shear bond strengths of glass-infiltrated alumina-ceramics to dentin. METHODS One hundred fifty ceramic discs of In-Ceram Spinell, In-Ceram Alumina and In-Ceram Zirconia (n=50) were prepared. Specimens which were divided into 5 groups (n=10) were untreated (control group), sandblasted, airborne particle abraded, etched with 9.6% hydrofluoric acid or irradiated with CO(2) laser. Scanning electron microscope was used at 1000x magnification for qualitative examination. Following surface roughness (Ra) determination by profilometry, discs were cemented on extracted-human-molar teeth. Cemented specimens were stored in distilled water at 37 degrees C for 1 week. Shear bond strength (MPa) test was performed using a universal testing machine at a crosshead speed of 1mm/min. Statistical comparisons were made with Wilcoxon signed ranked test, Kruskall Wallis test and Spearman's correlation coefficient. RESULTS All surface treatments produced rougher surfaces than the untreated groups of all ceramics (P<.05). Sandblasting demonstrated a rougher surface on In-Ceram Spinell than In-Ceram Alumina and In-Ceram Zirconia (P<.05). While CO(2) laser irradiation showed significantly higher bond strength for In-Ceram Spinell (P<.05), both airborne particle abrasion and CO(2) laser irradiation showed higher bond strengths for In-Ceram Zirconia (P<.05). Airborne particle abrasion demonstrated higher bond strength for In-Ceram Alumina and In-Ceram Zirconia (P<.05). No significant relationship was determined between surface roughness (Ra) and shear bond strength values (MPa) among ceramic groups. CONCLUSIONS Sandblasting is an effective surface treatment for roughening surfaces of In-Ceram Spinell. Although CO(2) laser irradiation does not increase surface roughness, it reveals the highest bond strength.

OBJECTIVES: To evaluate the hypothesis that a process of hydrofluoric acid precipitate neutralization and fatigue load cycling performed on human premolars restored with ceramic inlays had an influence on microtensile bond strength results (MTBS). METHODS: MOD inlay preparations were performed in 40 premolars (with their roots embedded in acrylic resin). Forty ceramic restorations were prepared using glass-ceramic (IPS Empress). The inner surfaces of all the restorations were etched with 10% hydrofluoric acid for 60 seconds, rinsed with water and dried. The specimens were divided into two groups

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.

AIM The aim of this study was to evaluate the clinical performance of IPS-Empress 2(R) all-ceramic crowns placed by general dental practitioners. METHODS AND MATERIALS Eighty-two IPS-Empress 2 crowns placed in 64 patients (27 females and 37 males) were evaluated. These crowns had been in place for 15.2 to 57.2 months (mean 25.3 months, SD=9.3). Survival analysis was conducted using the Kaplan-Meier method. RESULTS Of the 82 crowns 93.9% were rated satisfactory. In terms of the integrity of the restorations, fracture was observed in three crowns and two showed a crack upon transillumination. Five crowns were rated unsatisfactory for color match; one for marginal adaptation; and none for discoloration, secondary caries, or sensitivity. CONCLUSIONS IPS-Empress 2(R) is a suitable material to fabricate all-ceramic crowns; when these all-ceramic crowns were inserted by general dental practitioners, they functioned satisfactorily with low failure rates during an observation period ranging between 15.2 to 57.2 months.

The purpose of this study was to compare the fracture resistance and fracture mode of single implant-zirconium coping combinations using zirconium and titanium abutments and to analyze the stress distribution pattern using three-dimensional finite elements analysis. Twenty implants with titanium and zirconium abutments were randomly divided into two groups (n = 10) and into resin blocks. Zirconium copings were cemented onto the abutments. The specimens were loaded with 135° angles to the long axis and the load values at the moment of failure were recorded using a universal test machine. Stress levels were calculated according to the maximum Von Mises criteria. The fracture resistances for titanium and zirconium abutment groups were 525.65 N and 514.05 N, respectively. No significant differences were observed between two groups regarding the fracture resistance levels. The maximum Von Mises equivalent stress concentrated on zirconium copings in both of the groups. Implant-abutment-ZrO2 coping combination has the potential to withstand physiological occlusal forces in the anterior region. Three-dimensional finite elements analysis results of the implant-abutment-ZrO2 coping combination is compatible with the results of fracture resistance.

The aim of this study was to compare quantitatively the masticatory performance of patients with overdentures supported by two implants, conventional complete dentures, and natural dentitions. Each patient was asked to chew a gelatin cube. The collected remains of the test food (gelatine cube) were fractioned by a sieving procedure and weighed. Maximum mouth opening and masticatory area were measured using kinesiography. There were statistically significant differences among groups with respect to masticatory performance using a 3.15-mm-diameter sieve (P <.001) and 0.5-mm-diameter sieve (P <.001), masticatory area (P =.019), and maximum mouth opening (P <.001). Increasing retention of a mandibular complete denture with two implants improved masticatory performance.

The purpose of this study was to compare the fracture resistance and fracture mode of single implant-zirconium coping combinations using zirconium and titanium abutments and to analyse the stress distribution pattern using 3-D finite elements analysis. Twenty implants with titanium and zirconium abutments were randomly divided into two groups (n=10) and into resin blocks. Zirconium copings were cemented onto the abutments. The specimens were loaded with 135° angles to the long axis and the load values at the moment of failure were recorded using a universal test machine. Stress levels were calculated according to the maximum von Mises criteria. The fracture resistances for titanium and zirconium abutment groups were 525.65 N and 514.05 N, respectively. No significant differences were observed between two groups regarding the fracture resistance levels. Maximum von Mises equivalent stress concentrated on zirconium copings in both of the groups. Implant-abutment-ZrO2 coping combination has the potential to withstand physiological occlusal forces in the anterior region. 3-D finite elements analysis results of Implant-abutment-ZrO2 coping combination is compatible with the results of fracture resistance.

This in vitro study evaluated the effects of the different endodontic posts and surface conditioning on the fracture resistance and fracture modes of endodontically treated teeth. The experimental groups consisted of zirconia ceramic post with a glasss-ceramic core [A], zirconia ceramic post with a composite core [B], glass fiber composite post (FRC) with a composite core [C], and titanium post with a composite core [D]. All posts in these groups were cemented with self-adhesive resin cement (Rely X Unicem Aplicap) combination with tribochemical silica coating (TSC). Groups E, F, G and H comprised the same post-and-core materials as the first 4 groups but cemented with the same resin cement without TSC. Specimens were subjected to thermal cycling between 5 degrees C and 55 degrees C for a total of 5000 cycles with 30s per cycle. Static load was applied to the palatal surface of each specimen until they were fractured. Statistical analysis was conducted using analysis of variance (ANOVA) followed by post-hoc comparisons (Tukey). The fracture resistance was significantly affected by the post material (P < 0.001) and surface conditioning (P < 0.001; two-way ANOVA). The application of TSC to post surface decreased the fracture resistance of zirconia ceramic post with composite core (p=0.002; Tukey) and glass FRC post with composite core (p=0.029; Tukey). No catastrophic failure was observed for groups B, C, D, E, F and G. Under the testing conditions used, the titanium post/composite core that had been silicoated exhibited the highest fracture resistance.

The aim of this study was to investigate the effect of one particular brand of post and core system (ER Post) consisted of different post and core materials on the fracture resistance of endodontically treated teeth. Fifty caries-free maxillary central incisors were randomly assigned to five groups (n=10). All teeth were sectioned at the cemento-enamel junction except for the teeth in the control group. Four experimental groups consisted of cast gold post-and-core group (GG), Heraplat post/cast gold core group (HG), titanium post/composite core (TC), and titanium post/cast gold core (TG). The control group (ETT) consisted of endodontically treated teeth without posts. All posts were cemented in the roots with zinc phosphate cement. Following thermal cycling (5000 cycles between 5 degrees C and 55 degrees C with a dwell time of 30 seconds) a static load was applied to 2 mm below the incisal edge on the palatal surface of each specimen until they were fractured. Fracture data obtained and statistically analyzed with one-way ANOVA and a Tukey's test (p<0.05). Means of the fracture resistance during static loading were: 423.76 N (GG), 529.46 N (HG), 389.08 N (TC), 408.7 N (TG), 404.4 N (ETT, control). Heraplat post with cast gold core exhibited the highest fracture load than the other groups (p<0.05). Specimens in groups HG and ETT (control) showed the most repairable failure. Heraplat post with cast gold core had the highest fracture resistance of endodontically treated teeth.

PURPOSE To examine the effect of different adhesive luting systems on the shear bond strength of all-ceramic restorations to dentin surfaces. MATERIALS AND METHODS Forty-eight all-ceramic disks (2 x 3 mm; IPS e.max Press) were fabricated. Forty-eight noncarious extracted human molars were divided into 4 groups. in groups 1 to 4, IPS e.max Press disks were luted with Variolink 2/Excite DSC (etch-and-rinse), Clearfil Esthetic Cement/Clearfil Protect Bond (antibacterial and self-etching), Multilink/Multilink Primer (self-etching), or Multilink Sprint (self-adhesive). All specimens were subjected to 5000 thermocycles (5 degrees C to 55 degrees C, 30-s dwell time). Shear bond strengths were tested using a universal testing machine until failure. The analysis of the fractured dentin surfaces was performed using an optical microscope at 10X and 1000X magnification; the images were analyzed with an image analyzer. Data were analyzed with one-way ANOVA and Tukey's test at a significance level of p < 0.05. RESULTS Mean shear bond strength data of the groups in MPa were: Variolink 2/Excite DSC: 25.89 +/- 3.71; Clearfil Esthetic Cement/Clearfil Protect Bond: 17.21 +/- 2.71; Multilink/Multilink Primer: 11.6 +/- 3.51; Multilink Sprint: 10.4 +/- 3.15. According to the one-way ANOVA, there were significant differences in shear bond strength (p < 0.001). According to Tukey's test, statistically significant differences were observed in shear bond strength between groups 1 and 2 (p < 0.001), groups 1 and 3 (p < 0.001), groups 1 and 4 (p < 0.001), groups 2 and 3 (p = 0.003), and groups 2 and 4 (p < 0.001). Conclusion: The etch-and-rinse dentin bonding system produced higher bond strengths of all-ceramics to dentin surfaces than did the self-etching bonding systems and self-adhesive luting system.

PURPOSE: In this in-vitro study, microleakage of all-ceramic crowns was evaluated at enamel and dentin margins. MATERIALS AND METHODS: Forty maxillary central incisors were randomly divided into 4 groups (n = 10). While buccal and palatal margins were placed on enamel, mesial and distal margins were placed below the cementoenamel junction. In groups 1 to 3, IPS Empress 2 crowns were luted with Variolink 2/Syntac Classic (group 1), Bifix DC/Solobond Plus (group 2) and Calibra/Prime & Bond NT combinations (group 3), respectively. In the control group (group 4), porcelain-fused-to-metal crowns were luted with a zinc-phosphate cement. All specimens were subjected to 5000 thermocycles (at 5 degrees C to 55 degrees C; 30-s dwell time). After immersion in India ink for 48 h at 37 degrees C, the specimens were sectioned both buccolingually and mesiodistally. Each section was evaluated for microleakage under a stereomicroscope at 24X magnification. RESULTS: According to the Krukal-Wallis test, in all groups, there were significant differences in microleakage at the enamel margins (p = 0.001). Nevertheless, the margins finished in dentin showed no significant differences (p = 0.163). According to the Mann-Whitney U-test, statistically significant differences were observed in microleakage between groups 1 and 3 (p = 0.049), groups 1 and 4 (p = 0.001), groups 2 and 4 (p = 0.002), and between groups 3 and 4 (p = 0.045) at the enamel margin. In group 1, significantly greater microleakage was observed at the dentin margin compared to the enamel margin (p = 0.007). CONCLUSION: The adhesive luting technique demonstrated an excellent ability to minimize microleakage of all-ceramic crowns at the enamel margins. Water-based dentin bonding systems showed less microleakage than the water-free acetone-based dentin bonding system at the enamel margin.

OBJECTIVES: Effect of a dentin adhesive system containing antibacterial monomer-MDPB (Clearfil Protect Bond) on the shear bond strength of all-ceramic-IPS Empress 2 restorations luted with three different dual-polymerizing systems (Variolink 2, RelyX ARC and Panavia F 2.0) to dentin was investigated. METHODS: One hundred and eight all-ceramic discs (2x3mm; IPS Empress 2) were fabricated and ultrasonically cleaned. The buccal surfaces of 108 non-carious extracted human premolars were flattened to expose dentin and subsequently polished with 600-grit wet silicon carbide paper. Three dual-polymerizing luting systems had test groups and control groups consisting of 18 samples each. For the test groups Clearfil Protect Bond was applied to the exposed dentin surfaces. Control groups received the original bonding procedures of each adhesive system. After the all-ceramic samples were luted to the teeth, thermocycling was performed 5000 times. Shear bond strengths were tested using Shimadzu Universal Testing Machine until failure. Analysis of fractured dentin surfaces were performed using Optical Microscope at x10 and x1000 magnifications and the images were analyzed with Image Analyzer. Data was analyzed with one-way ANOVA and Bonferroni test at a significance level of p<0.05. RESULTS: Mean shear bond strength data of the groups in MPa were; Variolink: 20.45+/-4.75, Variolink+Clearfil Protect Bond:29.32+/-2.37, RelyX ARC:18.82+/-3.19, RelyX ARC+Clearfil Protect Bond:25.58+/-4.05, Panavia F 2.0:17.11+/-2.98, Panavia F 2.0+Clearfil Protect Bond:24.40+/-7.46. Application of the antibacterial adhesive increased the shear bond strengths of all three dual-polymerizing systems to dentin (p=0.00). The surface analysis showed that most of the specimens showed the adhesive failure mode between the dentin and the composite luting agent interface. CONCLUSION: The antibacterial adhesive system Clearfil Protect Bond can be safely used to prevent the potential risk of complications resulting from bacterial activity regardless of affecting the bond strength of IPS Empress 2 restorations luted with the dual-polimerizing systems used in this study.

There has been an increase in the use of esthetic metal-free ceramic crowns in restoring endodontically treated teeth or teeth with severe coronal destruction. Tooth-colored dowels and cores are used to enhance the esthetic result. This report describes the treatment of a patient with bilateral maxillary supernumerary lateral incisors, a severe malocclusion, and maxillary anterior tooth discoloration. Treatment included heat-pressed, metal-free ceramic crowns supported by zirconia ceramic dowel-and-core foundations.

The esthetic demands of patients have increased considerably during recent years. Due to this increasing interest in esthetics, as well as concerns about toxic and allergic reactions, the use of all-ceramic restorations has increased. One of the systems introduced for all-ceramic restorations is the IPS Empress system. This article examines one all-ceramic restoration system, IPS Empress, and presents patient cases in which all-ceramic crowns and fixed partial dentures have been utilized.

The aim of this prospective study was to evaluate the clinical outcomes of three and four-unit posterior fixed dental prostheses (FDPs) made of In-Ceram Zirconia. Twenty FDPs were inserted in 15 patients. Over a mean observation period of 74.6 months, the survival rate was 85%. Sixty-five percent of cases did not allow for connector dimensions that met the manufacturer's recommendations without the use of surgical procedures (eg, crown lengthening). Posterior all-ceramic FDPs made of In-Ceram Zirconia appear to be a viable prosthetic treatment option to replace a missing tooth.

The present clinical study evaluates the clinical prognosis of Cerec3D endocrowns over an observation period of two years. Twenty Cerec endocrowns (VITABLOCS Mark II, Vita Zahnfabirk, Bad Säckingen, Germany) were placed with PanaviaTM F 2.0, a dual-curing bonding composite. The control examinations took place semi-annually and the restorations were evaluated based on modified US Public Health Service criteria (USPHS). The two-year survival rate of the Cerec endocrowns was 90%. Two out of 20 endocrowns were assessed as failure because of fractures. The first fracture was observed after 12 months and the second fracture after 18 months. No recurrent caries was diagnosed during the entire examination period. Slight percussion symptoms were found on three restorations in the first weeks after placement. The results of the present study show that good esthetic and functional results similar to those of other restoration types can be achieved with endocrowns and that CAD/CAM-fabricated crowns represent a very promising treatment alternative for endodontically treated molars.

The purpose of this preliminary study was to evaluate the clinical performance of chairside-generated crowns over a preliminary time period of 24 months. Forty-one posterior crowns made of a machinable lithium disilicate ceramic for full-contour crowns were inserted in 34 patients using a chairside computer-aided design/computer-assisted manufacturing technique. The crowns were evaluated at baseline and after 6, 12, and 24 months according to modified United States Public Health Service criteria. After 2 years, all reexamined crowns (n = 39) were in situ; one abutment exhibited secondary caries and two abutments received root canal treatment. Within the limited observation period, the crowns revealed clinically satisfying results. Int J Prosthodont 2010;23:214-216.

Objective: To investigate the survival rate over a 3-year period of posterior resin composite restorations placed by dental students of Kuwait University. Materials andMethods: Posterior resin composite restorations placed by 5th-, 6th- and 7th-year dental students between 2004 and 2005 were evaluated. All patients with posterior composite restorations placed during this period of time were recalled. Of the 204 eligible patients, 139 attended the recall. 432 posterior resin composite restorations were evaluated clinically and radiographically according to the United States Public Health Service criteria. For each restoration, the survival time and/or reasons for failure were recorded. Descriptive statistics and logistic regression analysis were used to analyze the data at a statistically significant level of p < 0.05. Results: At 3 years, the survival rate of the restorations was 95.1%, resulting in an annual failure rate of 1.7%. Recurrent caries was the most common cause of failure (71.4%). Oral hygiene and gender and age of the patient were the factors that affected the failure rate of the restoration (p < 0.05). Other factors such as tooth type and location, type of cavity, type of liner used and level of the student who performed the procedure did not affect the failure rate (p > 0.05). Conclusion: Dental students of Kuwait University were able to place resin composite restorations in posterior teeth with a low annual failure rate. Recurrent caries was the most common cause of failure of posterior resin composite restorations. Oral hygiene was the most important factor in determining the survival of resin composite restorations.

One in every ten all-ceramic crowns fail after five years.

Summary The aim of this article was to report the results of an 18-month longitudinal randomized clinical trial that evaluated the clinical performance of microhybrid, packable and nanofilled resin composite restorations placed in Class I cavities of molar teeth. Three Class I resin composite restorations were placed in each of 35 patients. Each patient received one microhybrid ('Point 4'; Kerr, Orange, CA, USA), one packable ('Packable Premise'; Kerr, Orange, CA, USA) and one nanofilled ('Nanofilled Premise'; Kerr, Orange, CA, USA) resin composite restoration. Clinical evaluation was performed at baseline (2 weeks after placement), and after 6, 12 and 18 months after placement using modified Ryge criteria. No patients were lost from the study. At the final appointment (after 18 months), 95.4%, 93.7% and 96.2% respectively of the microhybrid ('Point 4'), packable ('Packable Premise' and nanofilled ('Nanofilled Premise') resin composite restorations received Alfa ratings. Regardless of the type of restorative material, no significant changes were observed in the modified Ryge criteria at the baseline and 18-month recalls (P </=0.05). Three restorations (one from each group) exhibited post-operative sensitivity at the baseline and 6-month appointment. After 18 months, one packable resin composite restoration failed because of secondary caries, while secondary caries was not detected on any of the other restorations. The clinical performance of microhybrid ('Point 4'), packable ('Packable Premise') and nanofilled ('Nanofilled Premise') resin composite restorations was acceptable after 18 months. Further studies with longer follow-up periods are recommended to investigate the long-term survival of these restorations.

PURPOSE: This study prospectively evaluated the clinical performance of posterior zirconium-oxide-based all-ceramic fixed partial dentures (FPDs). METHODS: Forty-two abutments of 21 Cercon FPDs were fitted in 20 patients at the Tsurumi University Dental Hospital from August 2005 to August 2006. The performance of these FPDs was evaluated using the California Dental Association (CDA) quality assessment system at baseline and at all follow-up examinations. RESULTS: All FPDs were examined after a mean observation period of 28.1 (+/-3.4) months. During the observation period, no fracturing of FPDs was seen. All of the FPDs examined were rated as satisfactory with regard to all factors at the follow-up examinations based on the CDA quality assessment criteria. CONCLUSION: Within the limitations of this short-term clinical study, no core framework fractures were seen. According to the CDA criteria, 100% of the FPDs were rated as satisfactory during this observation period.

OBJECTIVES This retrospective study evaluated the clinical performance and long-term survival of glass-ceramic lithium disilicate all-ceramic restorations in anterior and posterior areas over a 10-year period. METHOD AND MATERIALS Following a consistent protocol over 10 years, 261 lithium disilicate crowns (IPS Empress 2, Ivoclar Vivadent), including 101 anterior (38.7%) and 160 posterior (61.3%), were cemented using an adhesive technique and observed by the clinician who prepared and luted them. The data were analyzed using the Kaplan-Meier test. The clinical evaluation adopted the California Dental Association (CDA) modified criteria after recalling all patients between January and May 2008. RESULTS Six crowns failed and were replaced, 4 due to chipping and 2 due to core fracture. The overall survival rate was 95.5%. CONCLUSION In this retrospective evaluation, lithium disilicate ceramic restorations had a low clinical failure rate after up to 120 months.

This study compared the clinical performance of indirectly manufactured ceramic Evopress inlays with those of directly placed, fine particle hybrid Filtek Z250 composite restorations in posterior teeth. From January 2000 to October 2003, 109 patients received 264 Evopress (Wegold) ceramic inlays and 68 patients received 145 Filtek Z250 (3M ESPE) composite restorations in a dental office. Two-hundred and fifty ceramic inlays (95%) and 135 composite restorations (93%) were re-examined up to 57 months after placement. Modified USPHS criteria were used for the study. The worst finding of all the assessments was the overall assessment of individual restorations. On the basis of these criteria, 220 (88%) Evopress ceramic inlays were assessed as Alpha at the time of clinical re-examination, 26 (10%) were judged Beta and four ceramic inlays (2%) were rated Delta in the re-examination interval and thus categorized as failures. At the time of re-examination, 91 of the 135 composite restorations (67%) were judged Alpha, 36 restorations (26%) were rated Beta and three restorations (2%) were judged Charlie. Five restorations (4%) were categorized as failures (Delta). In two cases, there were marginal gap formations; there were also two cases of secondary caries after 28 and 35 months, as well as a fracture after 13 months. According to Kaplan and Meier, the survival rate after 57 months was 94% for ceramic inlays and 93% for composite restorations. The log rank test showed no significant differences in the survival curves. The current study showed that indirectly manufactured Evopress ceramic inlays performed better than direct Filtek Z250 composite restorations in marginal adaptation, color match and anatomic form. However, with regard to survival probability, there was no significant difference.

PURPOSE To observe the clinical effect of gold alloy porcelain fused metal (PFM) crown restoration and Ni-Cr alloy PFM crown restoration. METHODS A total of 168 teeth from 48 patients were restored with gold alloy PFM crown. The other 48 patients, with a total of 179 teeth were restored with Ni-Cr alloy PFM crown. They were examined in integrality, retention, shade, cervical margin, and gingival health immediately, 6 months, one year, two years ,and three years after restoration. The date was analyzed by rank sum test using SPSS12.0 software package. RESULTS The clinical effect of Ni-Cr alloy PFM crown was as good as gold alloy PFM crown when checked up after cementation at once. However, when they were examined 6 months, one year, two years ,and three years after restoration, the clinical effect of gold alloy PFM crown group was significantly better than that of Ni-Cr alloy PFM crown, P<0.05. CONCLUSION The gold alloy PFM crown has better properties than Ni-Cr alloy PFM crown as a kind of long-term restoration, especially on the aspect of shade.