Modified California Dental Association Research Articles

Clinical outcome of three different types of posterior all-ceramic crowns. A 3-year follow-up of a multicenter, randomized, controlled clinical trial.

To assess and compare the clinical outcomes of three different types of all-ceramic posterior monolithic tooth-supported crowns. A total of 71 patients received 90 all-ceramic crowns randomized to be either high-translucency zirconia (ZC), high-translucency zirconia with a partial buccal veneer (ZC-V), or lithium disilicate glass-ceramic (LDS). All treatments were performed by four general dentists. Choice of material was blinded. Baseline and subsequent annual evaluation were based on modified California Dental Association (CDA) criteria. A questionnaire was used to include patient-reported outcomes and to compare them to the crown quality rating performed by dentists. A total of 66 patients with 84 crowns were examined after 3 years. The survival rate was 98.8%. No crowns fractured during the observation period. One ZC-V crown failed due to loss of retention, and three complications were noted: loss of retention occurred in one ZC crown, and two ZC crowns needed to be endodontically treated. There was no significant difference between the different crowns regarding marginal integrity, surface, or anatomical form. Both patients and examining dentists rated the crowns favorably regarding esthetics, patients more than dentists. Posterior lithium disilicate glass-ceramic crowns and translucent zirconia crowns with or without a partial buccal veneer show excellent and promising clinical outcomes from a short-term perspective. Patients and dentists rate the restorations favorably concerning esthetics and function.

Clinical evaluation of zirconia crowns cemented with two different resin cements: A retrospective study.

Self-adhesive resin cement has been used extensively with zirconia crowns. Several in vitro studies showed that adhesive resin cementation may increase zirconia crowns' retention and their fatigue resistance. This retrospective study aimed to evaluate the clinical performance, survival and success rates and complications encountered with zirconia crowns cemented with two different self-adhesive resin cements. A total of 112 patients who received 176 monolithic zirconia crowns were evaluated. Crowns were cemented with RelyX Unicem 2 (n = 74) and Panavia SA (n = 102) self-adhesive resin cements. Clinical assessments of the crowns and supporting periodontal structures were performed following the modified California Dental Association (CDA) criteria. Intraoral photographs and periapical and bitewing radiographs were obtained for further assessment by two evaluators. Descriptive statistics, McNemar, t-test, log rank (Mantel-Cox) tests and Kaplan-Meier survival analyses were performed (a = .05). The 5-year survival and success rates were 100% and 96.4%, respectively. The complications encountered were recurrent caries (2.2%) and the need for endodontic treatment (0.5%). No technical complications, such as fracture or loss of retention, were observed. The type of cement and patient-related factors did not influence the survival and success rates of the crowns. Survival rate of zirconia crowns cemented with two different self-adhesive resin cements was 100% after 5 years.

Six-year clinical performance of lithium disilicate glass-ceramic CAD-CAM versus metal-ceramic crowns.

To assess the clinical performance of monolithic CAD-CAM lithium disilicate glass-ceramic (LDGC) crowns and metal-ceramic (MC) crowns provided by predoctoral students. This study also assessed the effects of patient and provider-related factors on their clinical performance as well as patient preference for these types of crowns. Twenty-five patients who received 50 crowns (25 LDGC CAD-CAM and 25 MC) provided by predoctoral students were retrospectively examined. LDGC CAD-CAM crowns were milled in-house using the CEREC Bluecam system and cemented with either RelyX Unicem or Calibra Esthetic resin cements. MC crowns were cemented with RelyX Unicem cement. Clinical assessment of the crowns and the supporting periodontal structures were performed following the modified California Dental Association (CDA) criteria. Patients' preference was recorded using a visual analog scale (VAS). The results were statistically analyzed using log-rank test, Pearson Chi-squared test and Kaplan-Meier survival analysis. Twelve complications were observed in the MC crown group (9-esthetic, 2-technical and 1-biological). In comparison, 2 complications in the LDGC CAD-CAM crown group were observed (1-technical and 1-esthetic). The 6-year cumulative survival rates for MC crowns and LDGC CAD-CAM were 90.8% and 96%, respectively, whereas the success rates were 83.4% and 96%, respectively. Overall, patients preferred the esthetic outcomes of LDGC CAD-CAM crowns over MC crowns. The high survival and success rates, low number of complications, and the high level of patients' acceptance of monolithic LDGC CAD-CAM crowns lend them well as predictable and viable alternatives to the "gold standard" MC crowns.

Clinical evaluation of 3D-printed zirconia crowns fabricated by selective laser melting (SLM) for posterior teeth restorations: Short-term pilot study

Background/purposeZirconia crowns (ZrC) without veneering porcelain have become an effective alternative in clinical practice. Monolithic zirconia restorations fabricated by the dry milling method do not have acceptable clinical properties. This study evaluated the periodontal qualities of three-dimensional printed ZrC using the modified United States Public Health Service (USPHS) criteria. Materials and methodsA total of 15 patients who required dental crowns were recruited, and all 15 teeth were restored with digital 3D-printed ZrC. All crowns were assessed at the time of crown placement and 2, 6, and 24 weeks post-placement. Clinical parameters, including plaque index, gingival index, probing depth, crown marginal integrity, and attrition of the antagonist's teeth, were evaluated and recorded. ResultsAccording to the Modified California Dental Association quality evaluation system, 100% of the crowns received satisfactory grades. Despite the significant increase in plaque index and gingival index at two weeks post-ZrC placement, there was no deterioration in probing depth. Moreover, there was discard usage of ZrC on the antagonist's teeth at 24 weeks posttreatment. Of the 15 crowns, one tooth had to be extracted due to a vertical root fracture. Overall, the digital 3D-printed crowns showed no adverse effects on periodontal tissues after 24 weeks of follow-up. ConclusionThe 3D-printed ZrC showed no periodontal problems. It can serve as an alternative for patients, particularly those with high esthetic expectations.

Retrospective 1- to 8-Year Follow-Up Study of Complete Oral Rehabilitation Using Monolithic Zirconia Restorations with Increased Vertical Dimension of Occlusion in Patients with Bruxism.

Aim: The aim of this paper is to perform a retrospective assessment of the clinical performance of the complete oral rehabilitation of patients with bruxism treated with implants and teeth-supported veneered and non-veneered monolithic zirconia restorations with increased occlusal vertical dimension. Methods: In this retrospective follow-up study, 16 bruxer patients, mean age 59.5 ± 14.9 years, were treated with 152 veneered and 229 non-veneered monolithic zirconia and followed for a mean of 58.8 ± 18.8 months (range 1–8 years). The patients were examined clinically and radiographically, annually. Clinical data were extracted from the medical records. In the recall appointments, modified California Dental Association (CDA) criteria were used to evaluate the restorations. Implant and restoration survival and success rates were recorded and analyzed. Results: The cumulative survival rates of implants and restorations were 97.7% and 97.6%, respectively. Nine restorations were replaced: three due to horizontal tooth fractures, two because of implant failure and four had secondary caries. A total of 43 biologic and technical complications were recorded. In the veneered group, the predominant complication was minor veneer chipping (16.4%), which required polishing only (grade 1). In the non-veneered group, the main complication was open proximal contacts between the implant restorations and adjacent teeth (14.5%). Conclusions: The survival rates of restorations and implants in patients with bruxism are excellent, even though veneered zirconia restoration exhibited a high rate of minor veneer chipping, which required polishing only. The biologic complication of fractured single-tooth abutment may occur.

Survival and Success Rates of Monolithic Zirconia Restorations Supported by Teeth and Implants in Bruxer versus Non-Bruxer Patients: A Retrospective Study.

The aim of this study was to assess retrospectively the survival and success rates of monolithic zirconia restorations supported by teeth and implants in bruxer versus non-bruxer patients. Methods: A total of 15 bruxer and 25 non-bruxer patients attended the recall appointment. The bruxer group (mean age of 61.2 ± 13.3 years and follow-up of 58.7 ± 16.8 months) were treated with 331 monolithic zirconia restorations, while the non-bruxer group, with a comparable mean age and follow-up time, were treated with 306 monolithic zirconia restorations. Clinical data were retrieved from the patients’ files. At the recall appointment, all supporting teeth and implants were examined for biological and technical complications, and the restorations were evaluated using modified California Dental Association (CDA) criteria. Data were statistically analyzed using survival analysis methods. A significance level of p < 0.05 was used. A total of 31 versus 27 biologic and technical complications were recorded in the bruxer and non-bruxer groups, respectively. No significant differences were found between the two groups regarding overall complications and survival rate. Regarding the type of complication, a significantly higher rate of veneered porcelain chipping (p = 0.045) was observed in the bruxer group. With regard to biological complications, the only complications that exhibited a borderline, although not significant, difference were three fractured teeth exclusively in the bruxer group (p = 0.051), which were replaced with implant-supported restorations. Within the limitations of this study, we conclude that there were no significant differences in the overall survival and success rates of the monolithic zirconia restorations in bruxer versus non-bruxer patients, although veneered zirconia restorations and single tooth abutments exhibited a higher rate of complications in the bruxer group.

Survival and success rates of soft-milled cobalt-chromium-ceramic full-arch screw-retained implant-supported prostheses: a 2- to 7-year follow-up retrospective study.

To retrospectively assess implant and prosthesis survival and success and patient satisfaction in edentulous patients treated with soft-milled cobalt-chromium-ceramic full-arch screw-retained implant-supported prostheses (SCCSIPs) over a mean clinical follow-up period of 4years. Twenty-one edentulous patients, aged 47-80years, underwent restoration with 27 SCCSIPs (210 implants, 349 crown units). After definitive prosthesis insertion, patients participated in a yearly dental check-up recall program, including clinical and radiographic examinations. All supporting implants were examined for biological and technical complications, and the restorations were evaluated using modified California Dental Association (CDA) criteria. Life table and Kaplan-Meier survival analyses were performed. Patient satisfaction regarding chewing, esthetics, comfort, and phonetics was evaluated using a visual analog scale (VAS). After a mean of 4years, two implants (3.8%) failed, with no effect on prosthesis survival. The cumulative survival rate was 98.6% and 100% for implants and prostheses, respectively. The most frequent minor biological complication was soft tissue recession (11%). Porcelain fracture was the only major technical complication (0.6% of crown units), while the only minor technical complication was porcelain chipping (4% of crown units), which required only polishing. Overall, 66.7% of the prostheses were free of technical complications. Patient satisfaction was high to very high. Less satisfaction was noted with comfort due to soft tissue recession and food impaction. Within the limitations of this study, we conclude that the survival and success rates of SCCSIPs in edentulous patients were excellent. SCCSIPs should be considered when planning metal-ceramic implant-supported restorations.

Clinical performance of CAD-CAM crowns provided by predoctoral students at the University of Toronto

Statement of problemThe clinical success of monolithic lithium disilicate glass-ceramic (LDGC) crowns manufactured with computer-aided design and computer-aided manufacturing (CAD-CAM) technology provided by predoctoral students has not been fully investigated. PurposeThe purpose of this retrospective clinical study was to evaluate the performance of laboratory-fabricated monolithic posterior LDGC CAD-CAM crowns provided by predoctoral students at the University of Toronto. Specific patient- and provider-related factors were also investigated. Material and methodsA sample of posterior LDGC CAD-CAM crowns (IPS e.max) provided by predoctoral students was evaluated. Crown preparations were made according to specific criteria, and crowns were milled in an in-house laboratory by using the CEREC Bluecam system. The crowns were cemented with Rely-X Unicem (3M ESPE) and Calibra Universal (Dentsply Sirona) resin cements. Clinical assessments of the crowns and supporting periodontal structures were performed following the modified California Dental Association (CDA) criteria. Intraoral photographs and periapical and bitewing radiographs were obtained for further assessment by 2 evaluators. Descriptive statistics, McNemar, t test, log rank (Mantel-Cox) tests, Pearson chi-squared tests, simple logistic regression, odds ratios, and Kaplan Meier survival analyses were performed (α=.05). ResultsA total of 189 patients receiving 210 crowns (108 premolar and 102 molar) were examined with a follow-up period of up to 6 years. Altogether, 28 complications were observed (12 technical, 11 biological, and 5 esthetic). No significant association was found between patient age, sex, periodontal condition, tooth type, tooth vitality, cement type, and crown longevity. However, significantly lower survival and success rates were found for mandibular crowns than for maxillary crowns (P=.029). The provider’s experience had no significant effect on the clinical performance of LDGC CAD-CAM crowns. The 6-year cumulative survival rate was 93.0%, and the success rate was 86.4%. ConclusionsThe ease of use of the CAD-CAM system and clinical performance of LDGC suggest that this technology should be used in the dental school setting by predoctoral students.

A Retrospective Clinical Study on 1075 Lithium Disilicate CAD/CAM Veneers with Feather-Edge Margins Cemented on 105 Patients.

To evaluate the clinical performance of lithium disilicate (LiDiSi) computer-aided- design/computer-assisted-manufacturing (CAD/CAM) veneers with feather-edge margins. Over 4 years (2015-2019), 1075 LiDiSi veneers with feather-edge margins were fabricated with a fully digital workflow and cemented on 105 patients. The outcome variables were survival of the restorations, colour matching, quality of the ceramic surface, presence of marginal discolouration and marginal integrity. The last four variables were assessed using the modified California Dental Association (CDA) and Ryge criteria. The mean observation period was 30.8 months. The cumulative survival rate was 99.83%. At the last follow-up control, the colour matching of the surviving 1074 restorations was rated Alpha (1064 veneers, 99.06%) and Bravo (10 veneers, 0.94%); the ceramic surface was rated Alpha (1070 veneers, 99.62%) and Bravo (4 veneers, 0.38%); the marginal discolouration was rated Alpha (1069 veneers, 99.53%) and Bravo (5 veneers, 0.47%); and the marginal integrity was rated Alpha (1070 veneers, 99.62%) and Bravo (4 veneers, 0.38%). CAD/CAM LiDiSi veneers with feather-edge margins fabricated with a fully digital workflow showed good clinical performance in terms of survival, colour matching, ceramic surface, marginal discolouration and integrity. Further, prospective and long-term studies are needed to confirm these positive results.

Five year clinical outcomes of metal ceramic and zirconia-based implant-supported dental prostheses: A retrospective study

ObjectivesThe implant-supported restorations can be made of all-ceramic materials. The purpose of this study was to compare five year clinical outcomes of zirconia-based and metal ceramic implant-supported fixed dental prostheses (FDPs). MethodsIn this study, 114 posterior implant-supported FDPs including zirconia-based (52) or metal ceramic (62) restorations were made for 114 patients with a mean age of 59 ± 8.4 years and evaluated in a 5 year follow up. The modified California Dental Association (CDA) guidelines were used to assess the quality of the restorations. The soft tissue status was evaluated using gingival and plaque indices, probing depth and bleeding on probing. Additionally, the bone loss around implants was assessed by parallel priapical radiographs. The visual analogue scale was used regarding patients’ satisfaction. The data analysis were performed by Kaplan-Meier, log rank test, Cox regression, Mann-Whitney U and Student’s t-test. (α = 0.05). ResultsFive year Kaplan-Meier survival rate of the zirconia-based and metal ceramic FDPs were 98.1 % and 100 % respectively with no significant difference (P = 0.12). The success rates were 81.6 % for zirconia-based and 81.0 % for metal ceramic restorations (P = 0.85). The CDA rating of both studied groups was not significantly different except the marginal gap which was better in zirconia-based FDPs (P < 0.001). Fracture of veneering ceramics occurred in 2.7 % of metal ceramic and 6.4 % of zirconia-based FDPs, which were not considered as failure. Soft tissue status was not affected by the type of restorations except for plaque index which was more favorable for zirconia-based FDPs (P < 0.001). No significant difference was found between marginal bone loss of the two groups (P = 0.30 mesial, P = 0.46 distal). ConclusionsZirconia-based and metal ceramic FDPs showed similar promising clinical performance in the 5-year follow-up. Clinical significanceZirconia-based implant-supported FDPs might be a successful restorative method with acceptable survival rate and patient's satisfaction.

Clinical evaluation of monolithic zirconia crowns for posterior teeth restorations.

Although all-ceramic crowns have excellent biocompatibility and esthetic appearance, chipping may occur. The mechanical properties of monolithic zirconia restorative material are superior to those of all-ceramic restorative materials, and chipping caused by chewing hard foods could be avoided. This study aimed to evaluate the clinical efficacy of monolithic zirconia crowns for posterior teeth restorations.A total of 46 patients requiring posterior teeth restorations involving 49 teeth were treated with monolithic zirconia crown procedure. The treatment results were evaluated according to the modified California Dental Association criteria immediately after the procedure, and at 2, 24, 48, and 96 weeks after the procedure. The plaque index, gingival index, probing depth, crown marginal integrity, and attrition of the abutment teeth, antagonist teeth, corresponding contralateral teeth, and antagonist of the corresponding contralateral teeth were assessed. The patients were followed for up to 96 weeks.The marginal adaptation results of all 46 patients were evaluated as excellent, resulting in an excellent rate of 100%. Regarding the crown color match, only 3 cases (6.1%) were evaluated as acceptable. Marginal adaptation, anatomic form, crown margin integrity, color match, and gross fracture did not show significant differences compared with the different time points (P = .999). Surface texture at different time did not change significantly (P = .807). During the 96-week follow-up, 1 crack in the antagonist teeth was found in 1 patient. There were no significant differences in wear of the antagonist teeth at different time points (P = .972). The rate of “excellent” evaluation for crown restorations was 93.9% to 100%.The monolithic zirconia crown had no detectable adverse effects on the periodontal tissues, and the antagonist teeth attrition was small. Therefore, it has good potential in the clinical application of posterior teeth restorations in the short term.

Clinical performance of chairside monolithic lithium disilicate glass-ceramic CAD-CAM crowns.

To evaluate the clinical performance and the effect of various patient and provider-related factors on the longevity of chairside monolithic posterior lithium disilicate glass-ceramic (LDGC) computer-aided design (CAD)-computer-aided manufacturing (CAM) crowns provided by predoctoral students. A sample of posterior LDGC CAD-CAM crowns was evaluated. Crown preparations were milled chairside using the CEREC Omnicam system and cemented with Rely-X Unicem or Calibra Universal resin cements. Clinical assessment of the crowns and supporting periodontal structures was performed using the modified California Dental Association (CDA) criteria. Intraoral photographs as well as radiographs were taken for further assessment by two evaluators. Kaplan-Meier survival analysis was performed. A total of 40 crowns were inserted in 32 patients and evaluated for 4 years. Three complications were observed (two-technical and one-biological). No chipping or fracture of crowns was observed. No significant association was found between age, sex, periodontal condition, tooth type, tooth vitality, cement type, and longevity. The 4-year cumulative survival and success rates were 95.0 and 92.3%, respectively. Chairside LDGC CAD-CAM crowns exhibited a high survival rate after 4 years in function and were shown to be a viable and reliable treatment option for posterior teeth. The high survival rate of chairside CAD-CAM crowns observed in this study suggests the likelihood of predictable performance in the predoctoral setup.

Complete rehabilitation of patients with bruxism by veneered and non-veneered zirconia restorations with an increased vertical dimension of occlusion: an observational case-series study

PurposeTo assess the clinical performance of the complete rehabilitation of a series of patients with bruxism treated by teeth- and implant-supported veneered and non-veneered zirconia restorations with an increased vertical dimension of occlusion (VDO). MethodsTen patients with bruxism, aged 62–70 years, were treated with 108 veneered and 142 non-veneered zirconia restorations and attended the recall appointment. The mean observation period was 28.2 (±16.8) months. The patients were identified from records, and clinical details were retrieved from their files. In the recall appointment, the restorations were evaluated using modified California Dental Association (CDA) criteria. The periodontal probing depth, bleeding index, presence of caries and implant survival and success rate were recorded. ResultsNo biological complications were recorded for any restorations. The success and survival rate of all implants was 100%. The overall mean survival and success rate of all restorations was 99.6%. In the veneered group, the predominant complication was minor veneer chipping (13.9%) on the incisal edge, which required only polishing (grade 1); in the non-veneered group, the predominant failure was open proximal contacts between the implant restoration and adjacent teeth (9%); only one implant restoration needed repair. One restoration was replaced due to a horizontal tooth fracture. ConclusionsWithin the limitations of this study, we conclude that the survival and success rate of monolithic zirconia restorations installed in patients with bruxism was excellent, although the veneered zirconia restorations showed a high rate of minor veneer chipping, which required only polishing.

Accuracy of crowns based on digital intraoral scanning compared to conventional impression—a split-mouth randomised clinical study

The aim of this prospective in vivo study was to evaluate the accuracy of the marginal and internal fit of crowns based on conventional impression (CI) or intraoral scan (IOS) in a randomised, split-mouth set-up. Nineteen patients needing full coverage crowns, fitting a split-mouth design, were provided with two lithium disilicate crowns: one based on a CI and one based on an IOS. The marginal and internal accuracy of the crowns were assessed with the replica technique and clinically using a modified California Dental Association (CDA) quality evaluation system. At the preparation margin, the median gap was 60μm for IOS and 78μm for CI. For the other points, the median gap ranged from 91 to 159μm for IOS and 109 to 181μm for CI. The accuracy of the IOS was statistically significantly better at all point except at the cusp tip. All crowns where rated R or S at both the 6- and 12-month follow-up appointments. The results for the clinical evaluation with CDA for marginal integrity showed no statistically significant difference between the two impression methods at both the 6- and 12-month evaluations. Crowns based on IOS show statistically significantly better marginal and internal adaptation before cementation compared to conventional impression. However, the clinical evaluation showed similar marginal adaptation. Crowns based on a fully digital workflow can provide clinically acceptable marginal adaptation, comparable to crowns based on CI.

Periodontal outcome and additional clinical quality criteria of lithium-disilicate restorations (Empress 2) after 14years.

To evaluate the clinical quality of tooth-supported crowns (SCs), implant-supported crowns (ISCs), and fixed dental prosthesis (FDPs) made of a lithium-disilicate glass-ceramic framework material (IPS Empress 2, Ivoclar Vivadent) after long-term use. Between 1997 and 1999, 184 restorations (106 SCs, 32 ISCs, 33 FDPs, 13 diverse restorations) were placed in 73 patients. In 2012/2013, all patients with functioning restorations were invited to participate in a clinical follow-up examination. To investigate the clinical quality, modified California Dental Association (CDA) criteria, periodontal health, and the patient's opinion were evaluated. After 14years on average, 50 restorations were available for evaluation of the CDA criteria and the patient's opinion, and 24 restorations were available for the periodontal health evaluation. Surface, color, anatomic shape, and margin integrity were considered to be in the range of excellence in 54, 78, 96, and 88%, respectively. There were no unacceptable defects. Most patients (64%) were still entirely satisfied with their restorations. Mean probing depths were significantly higher on teeth with tooth-supported Empress 2 restorations than on control teeth (p = 0.0401). No significant relationship was found between surface quality and plaque accumulation (p = 0.9450, generalized linear mixed model) or between surface quality and periodontal probing ≥ 4mm (p = 0.4184, generalized linear mixed model). The clinical quality of the Empress 2 restorations that had survived 14years on average was totally satisfactory with regard to esthetics, design, and patient's opinion. The periodontal health of all-ceramic restored teeth requires further investigation. The practitioner's choice of dental materials is based, at best, on long-term experience. With diminishing concerns about the clinical longevity of all-ceramic restorations, the grading of clinical quality based on esthetics, design, periodontal response, and patients' opinions could, nowadays, serve as a measure for the efficiency of dental ceramic.

Five year clinical outcomes and survival of chairside CAD/CAM ceramic laminate veneers — a retrospective study

PurposeThe aim of this clinical study was to compare the survival, modified California Dental Association (CDA) criteria, and periodontal parameters of laminate veneers made with Empress CAD and emax CAD over 60 months. MethodsOne hundred and ninety seven ceramic laminate veneers were placed in 71 patients in a private practice. The restorations were made using CEREC AC Bluecam with Empress CAD and emax CAD blocks. Modified CDA guidelines were used to evaluate clinical performance of the restorations. Gingival and plaque indices, probing pocket depth, and bleeding on probing were also recorded. Patient’s satisfaction was assessed using visual analogue scale. Kaplan–Meier and Log rank test were used to analyze survival probability and success rate of the restorations. CDA rating of Empress CAD and emax CAD was compared with Log rank test (α=0.05). ResultsThe survival rates of ceramic Empress CAD and emax CAD laminate veneers were 97.8 % and 100 % respectively (p=0.13). The success rate of these veneers was 92.4 % for Empress CAD and 100 % for emax CAD (p<0.05). Two Empress CAD laminate veneer failed because of fracture. Other restorations had very good or good CDA scores after 5 years. The periodontal parameters were not significantly different between first and fifth years except plaque index. The mean score of patients’ satisfaction was 95.5±8.4. ConclusionsChair-side computer-aided design/computer-aided manufacturing ceramic laminate veneers were clinically successful restorations with mean survival rate of 99.0 % and success rate of 96.4 % after 5 years.

Monolithic lithium disilicate complete single crowns with feather-edge preparation design in the posterior region: A multicentric retrospective study up to 12 years.

This retrospective study evaluated the clinical success and survival of monolithic lithium disilicate single crowns in the posterior region fabricated with feather-edge margins and cemented with resin-based self-etching cement. In total, 627 pressed monolithic lithium disilicate restorations on posterior teeth (110 first premolars, 151 second premolars, 240 first molars, 121 second molars, 5 third molars) were placed in 335 patients. All teeth were prepared with feather-edge margins and restored with single crowns. The modified California Dental Association criteria were used to clinically evaluate subjects during regular maintenance recalls. The mean follow-up time was 48.17 months (SD, 27.7; range, 6 to 144). Nine crowns were replaced during the follow-up period due to bulk fracture of the material (overall 97.93% survival rate), and four teeth were extracted. No other technical or biologic failure was observed. In this retrospective evaluation, monolithic lithium disilicate crowns with feather-edge margins yielded clinical outcomes similar to those reported with other margin designs and materials. Following the same clinical protocol, crowns on second molars showed lower survival rates when compared to restorations on other teeth in the posterior region. Careful evaluation is mandatory in high-risk patients and terminal teeth. Alternative restorative materials, such as full-contour zirconia crowns, should be considered for the restoration of second molars.

Effect of different cement types on monolithic lithium disilicate complete crowns with feather-edge preparation design in the posterior region

Statement of problemIdeally, tooth preparation for complete crowns should require the removal of the smallest amount possible of sound tooth structure to maximize the strength of the remaining tooth. Some preparation designs, such as the feather-edge margin, are less invasive. However, limited data are available regarding monolithic lithium disilicate crowns for molars and premolars with this type of margin geometry. PurposeThe purpose of this retrospective study was to evaluate the clinical outcome and survival of monolithic lithium disilicate crowns in the posterior region fabricated with feather-edge margins and cemented either with conventional (glass ionomer) or resin self-etching cement in 2 private practices. Material and methodsA total of 257 monolithic lithium disilicate restorations on posterior teeth (108 premolars, 149 molars) were placed in 158 patients. All teeth were prepared with feather-edge margins and restored with single crowns. The modified California Dental Association (CDA) criteria were used to clinically evaluate participants recalled between June and December 2014. ResultsThe mean ±standard deviation follow-up time was 24 (±13.6; range: 6-75) months. Three crowns were replaced during the follow-up period because of the bulk fracture of the material (98.83% survival rate). No other technical or biological failure was observed. ConclusionsIn this retrospective evaluation, monolithic lithium disilicate crowns with feather-edge margins yielded clinical outcomes similar to those reported with other margin designs and materials.

Clinical performance of CEREC AC Bluecam conservative ceramic restorations after five years—A retrospective study

ObjectivesThe aim of this study was to assess the clinical performance of CAD/CAM partial coverage posterior restorations made by CEREC AC Bluecam system after 5 years. Methods159 ceramic partial coverage posterior restorations were placed in 109 patients in a private practice. The restorations were made using CEREC AC Bluecam with CEREC Blocs or Empress CAD blocks. The clinical performance of the restorations was evaluated with modified California Dental Association (CDA) guidelines, gingival and plaque indices, probing pocket depth, and bleeding on probing in a period of 5 years. Patients’ satisfaction was assessed using visual analogue scale. The Kaplan–Meier method was used to analyze survival probability of the restorations (α=0.05). ResultsThe restorations included 102CEREC Blocs and 57 Empress CAD. The survival rates of CEREC Blocs and Empress CAD blocks were 96.0% and 94.6%, respectively (P=0.67). A total of 7 (4.5%) failures were found. The failures were not significantly influenced by restoration size, type and position of teeth. The ceramic fracture was significantly more in nonvital teeth (P=0.04). The periodontal parameters were not significantly different between the restored and control teeth except plaque index. The mean score of patients’ satisfaction was 94.4±8.1. ConclusionsChair-side CEREC AC ceramic partial coverage posterior restorations were clinically successful restorations with mean survival rate of 95.5% after 5 years. Clinical significanceConservative chair-side CAD/CAM ceramic restorations with less reduction of tooth structure can be a successful restorative method with acceptable survival rate and patient’s satisfaction.

A retrospective evaluation of zirconia-fixed partial dentures in general practices: An up to 13-year study

ObjectivesTo evaluate zirconia-based fixed partial dentures (FPDs) after more than 8 years in clinical service. MethodsPatients treated between 2000 and 2004 with zirconia FPDs were identified from the records of a manufacturer of FPD substructures. Of the 45 patients who met the inclusion criteria 30 attended the appointment and 33 FPDs were evaluated using modified California Dental Association (CDA) criteria. In addition, plaque and the bleeding index were registered. Patient satisfaction with the restorations was evaluated using a 10-point visual analog scale (VAS). ResultsAll the FPDs were made using CAD/CAM and hot isostatic pressed yttria-tetragonal zirconia polycrystal (HIPed Y-TZP) ceramic (Denzir) and were placed within general practices. The mean observation period was 9.6±1.6 years (range 3.0–13.1 years). The CDA rating was 90% satisfactory for the surface. Corresponding figures for anatomic form, color and margin integrity were 94%, 100% and 94%, respectively. Regarding surface three (9.7%) FPDs exhibited veneer chipping and were rated ‘not acceptable’. For margin integrity two (6.5%) were rated ‘not acceptable’ because of caries. For anatomic form two (6.1%) were rated ‘not acceptable’ due to two lost FPDs. No significant differences were seen between the FPDs and controls for plaque and bleeding. The Kaplan–Meier survival rate (still in clinical function) was 94%, the success rate (technical events accounted for) 91% and (biological events accounted for) 73%. Based on the VAS the mean value for patient satisfaction was 9.3±1.2. SignificanceNinety-four percent of the FPDs were still in clinical function. HIPed Y-TZP could serve as an alternative for FPD treatments similar to those in the current study.