Metal-ceramic Fixed Partial Dentures Research Articles

Complications Associated with Metal Ceramic Prosthesis in Fixed Partial Denture used in Peshawar

Background: Fixed Partial Dentures (FPDs) are a cornerstone in the restoration of missing teeth, offering both functional and aesthetic benefits. Metal-ceramic FPDs, in particular, have gained popularity due to their durability and mechanical properties. However, their associated complications can significantly impact patient satisfaction and prosthesis longevity. Objective: This study aims to investigate the complications associated with metal-ceramic FPDs in a Pakistani population, focusing on their prevalence, types, and distribution across different dental arches and locations. Methods: Conducted at Sardar Begum Dental College, Peshawar, Pakistan, this descriptive cross-sectional study involved 183 participants, selected via non-probability convenience sampling over 4 to 6 months. Participants aged 15 to 60 years, who had been wearing metal-ceramic FPDs for more than a month, were included. Data were collected through a structured questionnaire, with complications categorized into biological and technical issues. SPSS version 25 was utilized for data analysis, employing descriptive statistics to quantify the prevalence and distribution of complications. Results: The study identified pain on chewing (46.4%) and de-cementation (23.5%) as the most frequent complications. The distribution of complications was nearly even between the maxillary (49.1%) and mandibular (50.9%) arches, with a higher incidence in the posterior regions. Specifically, the mandibular posterior region recorded the most problems (45.4%), followed by the maxillary posterior (28.4%), maxillary anterior (20.8%), and mandibular anterior (5.5%) regions. Conclusion: The prevalence of complications associated with metal-ceramic FPDs, particularly pain on chewing and de-cementation, underscores the need for meticulous case selection, precise treatment planning, and enhanced patient education on oral hygiene. These measures are essential to improving the longevity of FPDs and patient satisfaction, highlighting the importance of a multidisciplinary approach in dental care.

Up to 10 years clinical performance of zirconia ceramic and metal-ceramic fixed partial dentures: A retrospective study

Statement of problemCompletely veneered zirconia ceramic (ZC) fixed partial dentures (FPDs) have been reported to have a higher incidence of ceramic chipping than the standard metal-ceramic FPDs. However, data from comparative long-term studies are sparse. PurposeThe purpose of this retrospective study was to compare the long-term survival, chipping-free survival, and success of ceramic-veneered high noble metal alloy (HN), base metal alloy (cobalt-chromium alloy) (CC), and ZC FPDs and to isolate risk factors for the incidence of failure, veneer chipping, and overall complications. Material and methodsData from 289 study participants (58.7% women; mean age, 57.97 ±11.51 years) provided with a total of 400 FPDs comprising 197 (49.3%) HN FPDs, 121 (30.3%) CC FPDs, and 82 (20.5%) ZC FPDs fabricated from presintered 3 mol% yttria-stabilized zirconia (mean time of service, 6.85 ±3.25 years) were evaluated. Of these, 278 (69.5%) FPDs were provided by dentists and 122 (30.5%) by dental students. Five- and 10-year survival, chipping-free survival, and success rates were calculated using the Kaplan–Meier method and compared with the log-rank test. Risk factors were assessed using Cox regression analysis. The study was exploratory, so all P values were considered exploratory and descriptive. ResultsThe 5- and 10-year survival rates were 94.7% and 77.8% for HN, 93.7% and 81.2% for CC, and 92.9% and 53.3% for ZC FPDs, respectively, indicating no clear difference in survival among the framework materials. The 5- and 10-year chipping-free rates were 94.1% and 82.8% for HN, 96.1% and 78.9% for CC, and 82.6% and 62.2% for ZC FPDs, respectively, indicating a difference between HN and ZC, and CC and ZC restorations. The 5- and 10-year success rates were 83.7% and 55.3% for HN, 86.5% and 51.4% for CC, and 68.9% and 30.2% for ZC FPDs, respectively, indicating a difference between HN and ZC, and CC and ZC restorations. The Cox regression model indicated framework material as an influencing risk factor for success, and this influence persisted when chipping was investigated. Compared with zirconia, the use of a metal alloy reduced the risk of chipping or the occurrence of complications by up to one-third. ConclusionsAll FPDs showed high 5-year survival rates and acceptable 10-year survival rates with no strong differences among the materials. Higher success and chipping-free rates were observed for both HN and CC restorations compared with ZC restorations. Metal frameworks had a lower risk for complications or veneer chipping than zirconia frameworks.

Clinical performance and patient satisfaction obtained with tooth-supported ceramic crowns and fixed partial dentures

Statement of problemStudies reporting survival rates along with patient-centered outcomes are necessary to select the appropriate restorative material for crowns and fixed partial dentures (FPDs). However, studies that report the survival and complication rates of lithium disilicate crowns and the performance of zirconia FPDs compared with metal-ceramic FPDs are lacking. PurposeThe purpose of this clinical study was to assess the failure and complication incidence of tooth-supported ceramic crowns and FPDs in function for at least 5 years. Groups included were pressed lithium disilicate crowns (CP), veneered pressed lithium disilicate crowns (CV), and computer-aided design and computer-aided manufacturing (CAD-CAM) lithium disilicate crowns (CC). Veneered zirconia-based FPDs (FPDC) were compared with metal-ceramic FPDs (FPDM). Outcomes were survival and failure, success and complications, periodontal conditions, and patient satisfaction assessed at 2 examinations (at baseline ≥1 year after delivery and at the follow-up examination ≥5 years of function). Material and methodsEighty-two participants with 158 restorations (CP=39, CV=16, CC=20, FPDM=30, FPDC=53) were examined (2.38 ±0.96 years after delivery) to form the baseline data. For the prospective follow-up examination, 70 participants with 141 restorations (CP=39, CV=15, CC=16, FPDM=28, FPDC=43) were examined 4.08 ±0.36 years later. ResultsAt the follow-up, restorations were in function for a mean of 6.44 ±1.14 years. Survival rates for crowns were 97.1% (CP=97.4%, CV=100%, and CC=93.8%) and 98.6% for FPDs (FPDM=96.4%, FPDC=100%). Among the 68 crowns, 1 technical and 4 biological complications were recorded. FPDs had more biological and technical complications than crowns (15/149 abutment teeth and 11/71 restorations). Technical complications were seen in 9.3% of zirconia FPDs compared with 25% for metal-ceramic FPDs. Complications were commonly observed at the baseline examination (crowns: 12/75 biological and 1/75 technical; FPDs: 40/174 abutment teeth with biological and 8/83 FPDs with technical complications). The periodontal conditions improved significantly after baseline. The patients reported a high level of satisfaction with the esthetics and function of the crowns and FPDs. ConclusionsSurvival rate for ceramic crowns and FPDs was 97.9% after a mean observation time of 6.44 ±1.14 years. Biological complications were more commonly observed than technical complications, and complications were more common in FPDs than in crowns. The complication rate was similar for zirconia FPDs and metal-ceramic FPDs. Adherence to strict maintenance measures may have reduced the risk of biological complications.

A Randomized Clinical Trial Comparing Zirconia and Metal-Ceramic Three-Unit Posterior Fixed Partial Dentures: A 5-Year Follow-Up.

To compare the survival, success rates, and biological/technical complications of posterior metal-ceramic (MC) and zirconia fixed partial dentures (FPDs). A total of 40 patients requiring 40 posterior FPDs were randomly assigned to receive 20 zirconia and 20 MC restorations. The restorations were examined 1 week (baseline) and 1, 3, and 5 years after the end of treatment. Technical and biological outcomes were compared. Data were statistically analyzed using the Wilcoxon signed-rank and Mann-Whitney U tests. The survival rates of both groups were 100%, and the success rates were 80% (zirconia) and 100% (MC). No biological complications were observed. Minor chipping was found in 20% of the zirconia restorations. No differences in periodontal parameters were observed between groups. Zirconia FPDs exhibited the same survival rate (100%) as MC FPDs after 5 years; however, the success rate was 80%, because an increased rate of chipping was observed in zirconia restorations.

The Influence of the Loading Mode on the Stress Distribution on the Connector Region of Metal‐ceramic and All‐ceramic Fixed Partial Denture

Studies pertaining to the mechanical behavior of fixed partial dentures (FPDs) frequently found the highest tensile stress values at the connector region when load is applied at the pontic central region. The connector region is considered the weakest point of the prosthesis with the greatest potential of fractures, regardless of the material used. This 2D finite element study compared the stress distribution on three-element all-ceramic and metal-ceramic FPDs with different loading conditions. Three FPD models were designed: (i) metal-ceramic FPD; (ii) all-ceramic FPD with the veneering porcelain only on the occlusal face; and (iii) all-ceramic FPD with the veneering porcelain on the occlusal and cervical face of the pontic. Loads of 100 N were applied following these simulations: (i) distributed on all working cusps; (ii) only on the abutment teeth; and (iii) only on the pontic. There is a significant change on the stress distribution and on the tensile stress values when the load configuration is changed. The stress distribution from the load applied on the abutments was significantly better compared with the other two load simulations. When the loads were applied on the pontic and distributed on all working cusps, the highest tensile stress values appeared on the cervical region of the connectors between the abutments and the pontic. However, when the load was applied on the abutment teeth, the maximum tensile stress value significantly decreased and was located on the occlusal region of the connectors. In fact, the load applied on the pontic region does not simulate the clinical situation. Studies using this load configuration have overestimated the connector regions as having the highest probability of failures.

All-ceramic and porcelain-fused-to-metal fixed partial dentures: a comparative study by 2D finite element analyses

All-ceramic fixed partial dentures (FPDs) have an esthetic approach for oral rehabilitation. However, metal-ceramic FPDs are best indicated in the posterior area where the follow-up studies found a lower failure rate. This 2D finite element study compared the stress distribution on 3-unit all-ceramic and metal-ceramic FPDs and identified the areas of major risk of failure. Three FPD models were designed: (1) metal-ceramic FPD; (2) All-ceramic FPD with the veneering porcelain on the occlusal and cervical surface of the abutment tooth; (3) All-ceramic FPD with the veneering porcelain only on the occlusal surface. A 100 N load was applied in an area of 0.5 mm2 on the working cusps, following these simulations: (1) on the abutment teeth and the pontic; (2) only on the abutment teeth; and (3) only on the pontic. Relative to the maximum stress values found for the physiological load, all-ceramic FPD with only occlusal veneering porcelain produced the lowest stress value (220 MPa), followed by all-ceramic FPD with cervical veneering porcelain (322 MPa) and metal-ceramic FPD (387 MPa). The stress distribution of the load applied on the abutments was significantly better compared to the other two load simulations. The highest principal stress values were low and limited in a small area for the three types of models under this load. When the load was applied on the pontic, the highest stress values appeared on the connector areas between the abutments and pontic. In conclusion, the best stress values and distribution were found for the all-ceramic FPD with the veneering porcelain only on the occlusal surface. However, in under clinical conditions, fatigue conditions and restoration defects must be considered.

A clinical evaluation of cobalt-chromium metal-ceramic fixed partial dentures and crowns: A three- to seven-year retrospective study

In severely compromised dentition, loading of long-span and cantilever metal-ceramic fixed partial dentures (FPDs) could result in framework deformation and porcelain fractures. The use of cobalt-chromium (Co-Cr) alloys may be advantageous, but there is little information on the longevity of, and complications with, prostheses made with these alloys. The aim of this retrospective study was to report the survival and complication rates of Co-Cr metal-ceramic FPDs and crowns followed over a 3- to 7-year period. The study included 42 patients with a total of 51 FPDs and 12 single crowns assigned to 1 of 3 groups. The 3 groups comprised patients with abutment teeth with a questionable prognosis (n=10), advanced chronic periodontitis (n=19), or abutment teeth with a positive prognosis (n=13). The FPDs had a mean of 9.7 units (range of 3-14). Of the FPDs, 32 were provided with a cantilever on 1 side (n=24) or both sides (n=8). The mean observation time was 51 months (range of 28-82). All patients were examined by 2 independent prosthodontists using the California Dental Association (CDA) assessment system for evaluation. One-way ANOVA with Fisher's LSD post hoc test and the Mann-Whitney U test were used for statistical analyses (alpha=.05). Seventeen (34%) of the FPDs had biological and/or technical complications. Six (12%) FPDs were completely or partially removed during the observation period, 1 framework fractured, and 9 (17.6%) FPDs had ceramic fractures. Fifteen of the 21 fractured FPD units were related to FPDs that were placed in 3 patients with bruxing habits. The CDA rating for marginal integrity was "excellent" for more than 98% of the abutments. No patients reported adverse reactions to the material. Metal-ceramic FPDs made of cobalt-chromium alloy performed acceptably in the questionable prognosis and advanced chronic periodontitis groups.

Clinical fit of all‐ceramic three‐unit fixed partial dentures, generated with three different CAD/CAM systems

In this study, the hypothesis was tested that the marginal and internal fit of CAD/CAM fabricated all-ceramic three-unit fixed partial dentures (FPDs) can be as good as in metal-ceramic FPDs. Twenty-four all-ceramic FPDs were fabricated and randomly subdivided into three equally sized groups. Eight frameworks were fabricated using the Digident CAD/CAM system (DIGI), another eight frameworks using the Cerec Inlab system (INLA). Vita Inceram Zirkonia blanks were used for both groups. In a third group frameworks were milled from yttrium-stabilized Zirconium blanks using the Lava system (LAVA). All frameworks were layered with ceramic veneering material. In addition, six three-unit metal-ceramic FPDs served as control group. All FPDs were evaluated using a replica technique with a light body silicone stabilized with a heavy body material. The replica samples were examined under microscope. The medians of marginal gaps were 75 microm for DIGI, 65 microm for LAVA and INLA and 54 microm for the conventional FPDs. Only the DIGI data differed significantly from those of the conventional FPDs. Within the limits of this study, the results suggest that the accuracy of CAD/CAM generated three-unit FPDs is satisfactory for clinical use.

Failures Related to Crowns and Fixed Partial Dentures Fabricated in a Nigerian Dental School

The purpose of this investigation was to document the failure rate and length of service of crowns and fixed partial dentures (FPDs) fabricated in a Nigerian dental school. The reasons for failure of the initial restorations and their length of service were also ascertained. Also, the numbers of retainers, pontics, and the types of restoration were recorded. Poor esthetics was the most frequent cause of failure, 66 units (40.5%); followed by fracture, 58 units (35.6%); and dental caries, 25 units (15.4%). These outcomes were contrary to findings previously reported in studies from western countries where dental caries was principally responsible for failures (22.0% to 38.0% of cases). The resin-retained FPDs had the shortest mean years of service at 2.7 years, while the three-unit metal-ceramic FPDs had the greatest longevity at 8.6 years. The overall mean years of service for replaced restorations were 5.6 years. The study found a decrease in the mean years of service as the number of units in the fixed-fixed partial dentures increased. This is in sharp contrast to previous reports where no relationship existed between length of service and the number of units in a FPD.

In vitro fracture resistance of posterior metal-ceramic and all-ceramic inlay-retained resin-bonded fixed partial dentures

Inlay-retained resin-bonded fixed partial dentures (RBFPDs) are conservative prosthetic restorations; however, their resistance to fracture is not clear. The purpose of this study was to compare fracture loads of posterior complete coverage metal-ceramic restorations with all-ceramic inlay-retained RBFPDs. Thirty-two posterior ceramic RBFPD restorations were divided into 4 groups (n=8): (1) Complete metal-ceramic fixed partial dentures (MC-FPDs) fabricated of Ni-Cr-based alloy (Wirolloy) and veneered with a ceramic (IPS d.SIGN) as the control group; (2) inlay-retained metal-ceramic (MC RBFPDs) with the same materials as the control; (3) inlay-retained lithium disilicate (LD) glass-ceramic (IPS Empress 2) RBFPDs; and (4) inlay-retained zirconia-based (Z) ceramic (Cercon) RBFPDs. Control specimens were prepared to receive conventional complete MC-FPDs designed to include a 1.3-mm-circumferential, 90-degree flat shoulder with rounded angles. Inlay-retained RBFPD specimens were prepared with 2-mm occlusal reduction but without bevels at the occlusal or gingival margins. Specimens were loaded and fracture loads (N) measured at fracture with a universal testing machine at a crosshead speed of 1.0 mm/min and 250 kgf load cell. Data were analyzed with 1-way ANOVA and Duncan test (alpha=.001). Fracture loads (mean +/- SD) were greatest for control specimens (1318.43 +/- 211.00 N) and Z-RBFPD (1247.70 +/- 262.51 N) specimens as compared to MC-RBFPD or LD-RBFPD (P < .001). MC-RBFPD exhibited the next highest fracture loads (958.01 +/- 194.29 N), and LD-RBFPD exhibited the significantly lowest values (303.23 +/- 92.54 N) of the materials tested (P < .001). Inlay-retained zirconia-based ceramic RBFPDs demonstrated the greatest fracture resistance among all inlay-retained restorations tested.

Pressed ceramic in fixed partial dentures construction

Purpose This study compares the marginal accuracy of posterior metal ceramic (MC), all-ceramic IPS Empress®2 and experimental pressed ceramic (EPC-VP 1989/4) three-unit fixed partial dentures (FPD), before and after luting and after thermo-mechanical fatigue in a dual-axis chewing simulator. Materials and methods Caries-free human teeth (n=160) were used as abutments for the fabrication of eighty posterior three-unit FPD, divided into two test-groups, IPS Empress®2 and EPC, of 32 samples each and one control group of 16 samples metal ceramic FPD. All FPD were cemented with Variolink®II dual-curing resin cement. Half of the samples in each group were exposed to a dual-axis chewing simulator. Results The geometric mean marginal gap values (μm, before cementation, after cementation and after thermo-mechanical fatigue) amounted to 53, 63 and 62 for the ceramic metal FPD, 57, 71 and 68 for the Empress®2 FPD and 55, 67 and 68 for the EPC FPD. In all groups a statistically significant increase in marginal gap width was observed after cementation. The effect of functional loading in the chewing simulator on marginal gap was not significant. Marginal gap was lowest in the control group but differences with all-ceramic materials were small in all evaluation stages. Conclusion Within the limits of this investigation, it can be concluded that marginal gap values of these all-ceramic materials and conventional MC techniques are on a similar level. In particular, almost all marginal gap values observed in this study were within the limits of clinical acceptance.