Full-ceramic resin-bonded fixed dental prostheses: A systematic review.

Despite the development of implant-supported prostheses, there are still patients for whom conservative treatments such as resin-bonded fixed dental prostheses (RBFDPs) are more appropriate. This study's objective was to analyze the available research on full-ceramic RBFDPs. In this study, Web of Science, MEDLINE/PubMed, Scopus, Embase, Cochrane Library, and Google Scholar databases were searched for articles published in English between 2010 and 2020. A total of 14 studies were reviewed based on the eligibility criteria. The results showed that using a cantilever design with one abutment had an advantage over two abutments. Additionally, it was proposed that preparations designed with retentive aids, such as a proximal box, groove, and pinhole, could improve RBFDP survival rates. IPS e.max ZirCAD, In-Ceram alumina, and zirconia CAD/CAM were the most commonly used framework materials. Most studies used air abrasion, salinization, or hydrofluoric acid for surface treatment. Adhesive resin cements were the most frequently used type of cement. The survival rate of In-Ceram ceramics (85.3%-94.8%) was lower than that of In-Ceram zirconia and IPS e.max ZirCAD. Debonding, followed by framework fracture, was the leading cause of failure. Following 3-10 years follow-up, the survival percentage of all-ceramic RBFDPs ranged from 76% to 100%. Although RBFDPs have demonstrated satisfactory success as a conservative treatment, long-term follow-ups and higher sample sizes in clinical research are required to gain more reliable outcomes on the clinical success rate of various RBFDP designs.

Metal-Ceramic Resin-Bonded Fixed Partial Dentures After a Mean Observation Time of 7.5 Years.

PURPOSE: To generate data on the long-term survival of metal-ceramic resin-bonded fixed partial dentures (RBFPDs). MATERIALS AND METHODS: A total of 89 patients received 94 RBFPDs, 5 of whom (women n = 1; men n = 4) received 2 RBFPDs each. All RBFPDs were fabricated as two-retainer end-abutment metal-ceramic restorations. Clinical follow-ups were performed 6 months after cementation and then annually thereafter. The mean observation time was 7.5 years. Cox regression was performed to test the effects of the variables: gender, location, arch, design, use of rubber dam, and adhesive luting system. Survival and success were calculated using Kaplan-Meier curves. As a secondary objective, patient and dentist satisfaction with the esthetics and function of the RBFPDs was evaluated. The significance level was set at α = .05 for all calculations. RESULTS: Estimated Kaplan-Meier failure-free survival was 97.5% (standard error [SE] 1.7) after 5 years and 83.3% (SE 5.3) after 10 years. Calculated intervention-free survival (success) was 90.1% (SE 3.4) after 5 years and 65.5% (SE 6.7) after 10 years. Debonding-free survival was 92.6% (SE 2.9) after 5 years and 80.6% (SE 5.4) after 10 years. Cox regression revealed that none of the four tested variables had a significant effect on the incidence of complications in RBFPDs. Patient and dentist satisfaction with RBFPD esthetics and function was consistently high throughout the observation period. CONCLUSIONS: Within the limitations of an observational study, RBFPDs achieved clinically successful outcomes over a mean observational period of 7.5 years.

Fracture strength of anterior cantilever resin-bonded fixed partial dentures fabricated from high translucency zirconia with different intaglio surface treatments.

PURPOSE: To compare the fracture resistance and failure modes of anterior cantilever resin-bonded fixed partial dentures (RBFPDs) fabricated from high translucency zirconia with different intaglio surface treatments. MATERIALS AND METHODS: Sound-extracted canines (N = 50) were randomly divided into five groups (n = 10) to be restored with high translucency zirconia RBFBDs of different intaglio surface treatments. The RBFPD was designed using exocad software and fabricated using a CAM milling machine. The RBFPDs were treated differently: abrasion with 50 µm alumina particles (Group 1); abrasion with 30 µm silica-coated alumina particles (Group 2); abrasion with silica-coated alumina particles (30 µm) and silane application (Group 3); abrasion with silica-coated alumina particles (30 µm) and 10-methacryloyloxydecyl dihydrogen phosphate (10-MDP) primer application (Group 4); abrasion with silica-coated alumina particles (30 µm) and silane, and 10-MDP primer application. All RBFPDs were cemented using dual-cured resin cement. The RBFPDs underwent 6000 thermal cycles with distilled water at 5/55°C for 2 min per cycle and then mechanical cyclic loading with 1200,000 cycles of 50 N at a 1.7 Hz frequency at an angle of 135° to the abutment's long axis. Then, RBFPDs were loaded to fracture using a universal testing machine at 1 mm/min. Maximum fracture forces and failure modes were recorded. Fractured specimens and uncemented specimens were examined using a scanning electron microscope. Data was analyzed using ANOVA and Games-Howell post hoc tests at p < 0.05. RESULTS: Mean fracture load results showed a statistically significant difference between the research groups (p < 0.0001) and it ranged from 69.78 to 584 N. Group 4 exhibited the highest fracture load mean (p < 0.0001) which was significantly different from all other groups. Group 2 recorded a significantly higher fracture load mean than Group 3 (p = 0.029). Three modes of failure were observed: prosthesis debonding, prosthesis fracture, and abutment fracture. CONCLUSIONS: Abrasion of zirconia surface with 30 µm silica-coated alumina particles and application of 10-MDP primer yielded the highest mean fracture loads of monolithic high translucency zirconia RBFPD. The mode of fracture of the RBFPDs was influenced by the type of surface treatments.

The cantilever contact-point resin bonded bridge; adhesion 2.0.

AIM: When young patients are congenitally missing anterior teeth, different treatment modalities can be used to complement the dental arch. This article proposes a new treatment modality for the replacement of anterior teeth, the cantilever contact-point resin bonded bridge (CCP-RBB). MATERIALS AND METHODS: In this proof of principle study, CCP-RBB's delivered by one operator were clinically assessed. Patients who were missing maxillary incisors and had suitable intra-oral conditions for a contact-point cantilever RBB were included. Three cases are presented to describe all adhesive steps. This proof of principle clinical study is presented with up to 60 months follow-up of the cantilever contact resin bonded bridges. RESULTS: A total of 19 CCP-RBB's were evaluated after a mean period of 29.8 months. None of the restorations exhibited failure, carious lesions or fractures during the follow-up periods, demonstrating an absence of restoration debonding or the need for repair. CONCLUSION: The new cantilever contact-point resin bonded bridge exhibited an excellent treatment modality without failure or debonding up to 5 years. More and extended duration in vivo studies are needed to evaluate this new treatment modality. CLINICAL SIGNIFICANCE: In this proof of principle the new cantilever contact-point resin bonded bridge obtained excellent results up to 5 years of clinical follow-up.

[Long-term clinical evaluation of different types of resin-bonded fixed partial denture to replace lost anterior teeth].

Objective: To evaluate the clinical survival rates and influence factors of different types of resin-bonded fixed partial dentures (RBFPD) used in anterior missing teeth restoration. Methods: Ninety-three RBFPD were delivered to 92 patients [92 patients,43 males and 49 females, average age (46.1±12.8) years] who visited Peking University School and Hospital of Stomatology from January 2006 to December 2021 for restoration of 1 or 2 anterior missing teeth. Altogether 32 cases of glass fiber reinforced RBFPD, 39 cases of glass-based ceramic RBFPD and 22 cases of porcelain-fused-to-metal RBFPD were retrospectively analyzed. The complete survival rate, functional survival rate, patients' satisfaction and color matching of the restorations were recorded and evaluated every year since the replacement with RBFPD. The Kaplan-Meier survival curve method was used for survival analysis, and the Log-rank analysis was used to compare the effect of the number of missing teeth, position (maxillary or mandibular), cantilever or non-cantilever and gender on the survival rate of the restorations. Results: The overall survival time for the 93 RBFPD was 13.7 years (95%CI: 12.3-15.1 years). There was a decreasing trend in complete survival and functional survival for all three material RBFPD from year to year, but complete and functional survival rates exceeded 90% at year 5 and exceeded 80% at year 10. The complete survival rate of the glass-ceramic RBFPD was higher than the other two during the follow-up period, with a complete survival rate of 90% (35/39) at year 15. The porcelain-fused-to-metal RBFPD had a higher functional survival rate in years 1-8, but the complete and functional survival rates showed a substantial decrease after year 9. The single-factor Log-rank analysis showed that the success rate of porcelain-fused-to-metal RBFPD was significantly higher than that of glass fiber reinforced RBFPD (χ²=7.33, P=0.007), and the success rate of RBFPD with 1 missing tooth restored was significantly higher than that of RBFPD with 2 missing teeth restored (χ²=3.23, P=0.072). The differences in success rates between different restoration positions (maxillary and mandibular), cantilever or non-cantilever, and gender factors were not statistically significant (χ²=2.26, P=0.133; χ²=0.68, P=0.411; χ²=1.07, P=0.300). Conclusions: For the restoration of individual missing anterior teeth, both porcelain-fused-to-metal RBFPD and glass-based ceramic RBFPD achieve a high long-term clinical success rate, with glass-based ceramic RBFPD being more able to ensure long-term restorative result.

Practical advice for successful clinical treatment with resin-bonded bridges.

Resin-bonded bridges are one of the main options for replacing missing teeth for hypodontia patients. This technique offers several advantages for these patients, who are often young, have unrestored abutment teeth, and have had tooth positions optimised by orthodontic treatment. However, the replacement of missing teeth can be challenging due to tooth positions and anomalies of abutment tooth shape and size.These patients are often young adults at the time of restoration, making the minimally invasive nature and predictable long-term success of resin-bonded bridges advantageous over other treatment methods.This paper in the hypodontia themed issue discusses the importance of case selection and gives practical advice for the design and provision of resin-bonded bridges.

Esthetic and functional rehabilitation of a patient with a bilateral cleft of lip, alveolar process, and palate with anterior all-ceramic cantilever resin-bonded fixed dental prostheses.

OBJECTIVES: Addressing a single-tooth gap in the anterior region, resulting from aplasia or trauma, poses both esthetic and functional challenges. This case report presents the restoration of a young adult with a cleft, exhibiting anterior hypoplasia and aplasia in the canine and incisor regions, using all-ceramic cantilever resin-bonded fixed dental prostheses. METHOD AND MATERIALS: After verification of esthetic and functional considerations through a diagnostic wax-up and an intraoral mock-up, three anterior all-ceramic cantilever resin-bonded fixed dental prostheses made of veneered zirconium dioxide were planned in the region of the maxillary right lateral incisor and maxillary left canine. The impression was made with an intraoral scanner. The framework fit was evaluated. Glaze firing and full adhesive cementation under rubber dam followed. RESULTS: The final restoration met the patients' expectations and restored facial esthetics and function. CONCLUSIONS: All-ceramic cantilever resin-bonded fixed dental prostheses offer a promising minimally invasive therapeutic option for cleft patients.

Patient satisfaction following resin-bonded fixed dental prostheses cemented by using the Dahl concept.

OBJECTIVE: Resin-bonded fixed dental prostheses (RBFDPs) cemented at an increased occlusal vertical dimension (OVD) (the Dahl concept) to create space for a metal retainer remains controversial because of the lack of reported clinical studies. This study analyzed the demographic (age and sex) and clinical factors (location and arch of prosthesis) affecting the patients' perception of RBFDPs cemented at an increased OVD. MATERIAL AND METHODS: Twenty-eight participants treated with cantilevered RBFDP at an increased OVD were prospectively recruited. They were asked to answer a validated patient satisfaction questionnaire based on six parameters during the 12-week review visit. RESULTS: 71.4% of the participants were completely satisfied with the color, shape, and function. Twenty-one (75%) participants reported no complaints about the prostheses. 89.3% will recommend this treatment option to others. There was a significant difference between males and females in avoiding loading on the prostheses (p = 0.015). The level of satisfaction did not differ by age, ethnicity, location, and arch of the prostheses (p > 0.05). CONCLUSIONS: Patient satisfaction toward RBFDP cemented by using the Dahl approach was generally high on all the parameters at the 12-week review visit.

Resin-bonded attachments made of monolithic zirconia ceramic: a minimally invasive and esthetic treatment approach.

OBJECTIVE: The aim of this case report was to present a minimally invasive and esthetic treatment approach for the replacement of missing teeth removable partial dentures retained by zirconia ceramic resin-bonded attachments. METHOD AND MATERIALS: The resin-bonded attachments were digitally designed and milled using CAD/CAM technology from monolithic 3Y-TZP zirconia ceramic. The resin-bonded attachments had an optimized attachment design approved for zirconia ceramic. The preparation was based on general preparation guidelines for resin-bonded attachments and resin-bonded fixed dental prostheses (RBFDPs). After placement of rubber dam, the resin-bonded attachments were bonded with a phosphate monomer-containing luting resin. RESULTS: The presented resin-bonded attachment-retained removable partial denture was successful over 30 months of clinical observation without any complications. The patient was satisfied with the minimally invasive treatment procedure. CONCLUSION: Zirconia ceramic resin-bonded attachments fabricated with a special attachment design are an esthetic and minimally invasive treatment approach. However, clinical data on the long-term outcome of zirconia resin-bonded attachments are still needed. (Quintessence Int 2023;54:220-226; doi: 10.3290/j.qi.b3819523).

Replacement of Two Missing Adjacent Teeth with Two Single-Retainer Resin-Bonded Fixed Dental Prostheses with Improved Proximal Design.

PURPOSE: To present a minimally invasive treatment approach for the replacement of two missing adjacent teeth with two single-retainer resin-bonded fixed dental prostheses (RBFDPs). MATERIALS AND METHODS: Two missing adjacent premolars were restored by two RBFDPs with an innovative design of the proximal section. Both RBFDPs were digitally designed and milled from monolithic 3Y-TZP zirconia ceramic using CAD/CAM. Following construction of the anterior RBFDP, a shallow interlock was designed in the area of proximal contact in the same insertion direction as the posterior RBFDP. In this way, different paths of insertion of the RBFDPs could be provided without compromising the proximal hygiene capability. RESULTS: The presented minimally invasive restorations were successful over 5 years of clinical bservation without any complications. CONCLUSION: The presented restoration design secures the transversal position of the RBFDPs while maintaining physiologic tooth mobility. In addition, it allows for varying paths of insertion while improving hygienic conditions. Last, in case of a unilateral debonding of one retainer wing, rebonding might be possible. Int J Prosthodont 2023;36:155-160. doi: 10.11607/ijp.7711.

Prospective Clinical Split-Mouth Study of Two-Wing­Retained Resin-Bonded Anterior Fixed Dental Prostheses with Metallic and Ceramic Frameworks: 5-year Results

PURPOSE: To analyze the clinical performance of two-wing­retained resin-bonded fixed dental prostheses (RBFDPs) after 5 years of clinical use with respect to technical and biologic complications, as well as survival and success rates. MATERIALS AND METHODS: RBFDPs were fabricated from 3Y-TZP zirconia layered by hand (Lava Frame veneered with Lava Ceram; 3M ESPE) or metal (Remanium Star, Dentaurum; layered with Reflex, Wieland). The primary endpoints were debonding and fracture. The secondary endpoints (marginal integrity, marginal discoloration, abrasion of antagonist dentition, patient satisfaction, Gingival Index, and side effects) were evaluated at baseline and after 5 years. Survival and success rates were calculated using the Kaplan-Meier method. Log-rank test was used to compare the survival and success rates of the different materials. RESULTS: The mean observation time was 6 years and 10 months. The estimated cumulative success rate after 5 years was 88.9% ± 10% for metal-supported and 33% ± 16% for all-ceramic two-wing RBFDPs. After conversion into one-wing RBFDPs, the survival rate was 100% in both groups. Debonding of one of the two wings was the major complication. One zirconia framework fracture occurred. Metal-based two-wing RBFDPs showed a significantly higher success rate, but lower esthetic evaluation. CONCLUSION: Due to a reduction in technical complication rate and less invasiveness, one-wing RBFDPs should be preferred over two-wing RBFDPs whenever possible.

Designing anterior cantilever resin-bonded fixed dental prostheses based on finite element analysis.

PURPOSE: A resin-bonded bridge (RBB) is a minimally invasive prosthetic treatment option for intact adjacent teeth. However, it is contentious as to whether the mesial or distal adjacent tooth should be used as an abutment. This study aimed to investigate the potential of finite element analysis (FEA) for the selection of abutment teeth and the determination of the optimal design for anterior cantilever RBBs. METHODS: Three types of RBBs were designed to simulate loss of the maxillary left lateral incisor. The fixed-fixed RBB (FF-RBB) had one retainer each for the left central incisor and canine. Distal- and mesial-cantilever RBBs (D-CRBB and M-CRBB) had a single retainer on the central incisor and canine, respectively. Three-dimensional models for FEA were generated from computed tomography slices and dental casts. FEA was performed for each RBB to evaluate stresses in the intercuspal, protrusive, and lateral mandibular positions. RESULTS: The maximum principal stresses on the bridges in the intercuspal position were 141.9 MPa, 93.6 MPa, and 45.7 MPa, for the FF-RBB, D-CRBB, and M-CRBB, respectively. The stress in the D-CRBB position was greater than in the M-CRBB position in the intercuspal, protrusive, and lateral mandibular positions. CONCLUSIONS: Based on the results, M-CRBB on the canine had a higher clinical performance than D-CRBB on the central incisor. FEA was useful for determining the optimal design of RBB for each patient.

Effect of different designs of minimally invasive cantilever resin-bonded fixed dental prostheses replacing mandibular premolar: Long-term fracture load and 3D finite element analysis.

PURPOSE: To evaluate the fracture load and stress magnitude of different retainer designs of minimally invasive cantilever resin-bonded fixed dental prostheses (RBFDPs) after artificial aging. MATERIALS AND METHODS: Fifty caries-free human mandibular molars were prepared as abutments for cantilever fixed dental prostheses using different retainer designs: one wing (OW), two wings (TW), inlay ring (IR), lingual coverage (LC), and occlusal coverage (OC). Computer-aided design and computer-aided manufacturing were used for milling the RBFDPs using fiber-reinforced composite (FRC), and the restorations were adhesively bonded. The specimens were then subjected to thermomechanical aging and loaded until failure. The 3D finite element analysis (FEA) was performed with five models of retainer designs similar to the in vitro test. Modified von Mises stress values on enamel, dentine, luting resin, and restorations were examined. Data were analyzed with Kruskal-Wallis and Mann-Whitney U tests (p < 0.001). RESULTS: A statistically significant difference (p < 0.001) was found between all groups except between IR and LC and between OW and TW designs, with the highest mean failure load detected for OC (534.70 N) and the lowest detected for OW (129.80 N). With regard to failure mode, OW, TW, and LC showed more incidences of favorable failure patterns than IR and OC designs. FEA showed that FRC transmitted low stresses in tooth structure and high stresses to the luting resin. CONCLUSIONS: LC and OC designs can be used to design cantilever RBFDPs in premolar area. IR design transmitted more stresses to the tooth structure and resulted in 30% catastrophic failure. OW and TW were below the normal occlusal force and should be carefully used.

A Digital Way for Fabricating a Resin-Bonded Fixed Partial Denture Combined with Periodontal Splint in the Mandibular Anterior Region.

Teeth loosening are caused by insufficient supporting tissue, inflammation of periodontal tissue, or occlusal trauma, which is one of the main clinical symptoms of periodontitis. A digital technique for fabricating resin-bonded splinting fixed partial dentures (S-FPDs) is presented. It restores the missing mandible anterior teeth and splints the adjacent periodontally mobile teeth of the patient at the same time. The S-FPDs is designed and fabricated by computer-aided design and computer-aided manufacturing (CAD/CAM) technology with flexible PMMA material. The workflow is straightforward, convenient, and accurate. Meanwhile, the restoration can meet the esthetic requirements and help with the stability of adjacent loosening natural teeth spontaneously. It could be considered a medium-term provisional restorative treatment option, but further controlled investigations still be needed.

CAD/CAM single-retainer monolithic zirconia ceramic resin-bonded fixed partial dentures bonded with two different resin cements: Up to 40 months clinical results of a randomized-controlled pilot study.

PURPOSE: This pilot study was part of a larger study planned for the future which aimed to compare the clinical success of two different resin cements used in the cementation of CAD/CAM single-retainer monolithic zirconia ceramic resin-bonded fixed dentures (RBFPDs). METHODS: Twenty-four RBFPDs were fabricated with monolithic zirconia (Katana™ Zirconia HT, Kuraray Noritake Dental Inc, Tokyo, Japan). Panavia F2.0 (PF2.0; n = 12) and Panavia V5 (PV5; n = 12) were used for cementation. The survival period was defined as the time when the restoration was placed in the mouth and lasted until an irreparable damage occurred. The repairable failures were identified as relative and irreparable failures were identified as absolute failure. The survival rate of the RBFPDs was determined by the Kaplan-Meier estimator. Statistical significance was set at p < 0.05. RESULTS: The mean observation times of the PF2.0 group and the PV5 group were 40.45 ± 6.15 months and 40.18 ± 6.41 months, respectively. Four failures occurred in the PF2.0 group. No failure was observed in the PV5 group. The curves of survival rate (PF2.0 = 80%, PV5 = 100%) showed no statistically significant difference (p = 0.031), although success rate (PF2.0 = 66.7%, PV5 = 100%) showed statistically significant difference (p = 0.317). CONCLUSION: Up to 40 months mean follow-up period, performance of RBFPDs bonded with PV5 was better than with PF2.0. CLINICAL SIGNIFICANCE: For clinicians, it is a matter of hesitation to apply single-retainer RBFPDs. This study contains results of 40 months (minimum 32, maximum 50.47 months) clinical follow-ups of single-retainer RBFPDs. These results will enlighten clinicians about the clinical success of the resin cement type for single-retainer monolithic zirconia ceramic RBFPDs.

Retention durability of one-retainer versus two-retainer posterior RBFDPs after chewing simulation.

The clinical use of one-retainer RBFDPs in the anterior region has shown higher survival rates compared to conventional two-retainer RBFDPs. The motivation for this study was to assess the validity of this observation when extended to the posterior region. The aim was thus to evaluate different preparation and framework designs for replacing premolars, particularly one-retainer versus two-retainer designs, on the retention of monolithic zirconia posterior RBFDPs. Extracted caries-free human premolars and third molars were embedded in auto-curing resin to create models with an edentulous space of premolar width. Abutment teeth were prepared according to these six designs (n = 8 each): one or two upper retainers with narrow rests, one or two upper retainers with wide rests, and one or two-retainers with wide rests. RBFDPs were milled from monolithic zirconia (KATANA Zirconia HT), and were adhesively bonded using Panavia V5 with corresponding primers. After thermodynamic loading, the quasi-static tensile force required for failure was determined. Failure modes were evaluated using a microscope. Survival rates after thermodynamic loading were 75% for one group (one upper-molar retainer with narrow rest), 100% for the other groups. The debonding forces ranged from 310 ± 224 N (group one upper-molar retainer with narrow rest) to 927 ± 292 N (group two upper retainers with narrow rests). Two-retainer designs failed at significantly higher tensile forces than designs with one retainer (p ≤ 0.05). There were no significant differences between upper and lower designs, or rest widths. Although RBFDPs with two retainers withstood higher debonding forces, RBFDPs with one retainer and wide rest still have a high potential for clinical treatment because of the high forces required for their debonding.

Longevity of immediate rehabilitation with direct metal-wire reinforced composite fixed partial dentures.

OBJECTIVES: This study aimed to analyze the longevity of direct metal-wire reinforced composite fixed partial dentures (MRC-FPD) and factors influencing their survival and success. METHODS: Within one private practice 513 MRC-FPD were directly applied. The preparation of a proximal cavity in abutment teeth was not limited. MRC-FPD were reinforced by one to three metal-wires. At the last follow-up MRC-FPD were considered successful, if they were still in function without any need of therapy. MRC-FPD were considered as survived, if they were repaired or replaced. Multi-level Cox proportional hazard models were used to evaluate the association between clinical factors and time. RESULTS: Mean follow-up period (range) was 59(2-249) months. Seventy-three bridges did not survive (cumulative survival rate(CSR):86%) and further 129 bridges had received a restorative follow-up treatment (CSR:61%). AFR was 2.2% for survival and 8.6% for success. In multivariate analysis MRC-FPD with> 1 wire showed a up to 2.3x higher failure rate than MRC-FPD with one wire(p ≤ 0.023). Dentist's experience in designing MRC-FDP (p ≤ 0.017), patient's caries risk (p ≤ 0.040) and bruxism (p = 0.033) significantly influenced the failure rate: the more experience, the lower caries risk and bruxism, the lower the failure rate. SIGNIFICANCE: For directly prepared metal-wire reinforced composite bridges high survival and moderate success rates were observed. MRC-FPD might, thus, be an immediate, short- and medium-term solution for replacing missing teeth. However, several factors on the levels of practice (dentist's experience in designing MRC-FDP), patient (bruxism, caries risk) and restoration (number of wires) were identified as significant predictors for the failure rate. The study was registered in the German Clinical Trials Register (DRKS-ID: DRKS00021576).

Debonding of cast metal-based cantilever and fixed-fixed resin-retained bridgework: A review of the literature.

AIM: Cast metal-based resin-retained bridgework (RRB) offers a practical, conservative approach when restoring edentulous spaces. This review examines the debonding of cast metal-based RRB, comparing cantilever resin-retained bridgework (CRRB) and fixed-fixed resin-retained bridgework (FRRB) designs taking into context developments in RRB design, construction, and cementation over time. METHODS: An electronic search was conducted through Medline and Embase with the aid of Boolean operators to combine the following key words: "adhesive bridges", "resin-bonded bridges", "resin-retained bridges", "resin-bonded fixed partial dentures", "cantilever", "debond", "fixed-fixed", "decementation", "failure", "success", "outcome", "longevity" and "survival". The search was limited to peer-reviewed articles written in English and published from 1995 through to 2019. MAIN FINDINGS: Thirty-one studies were included. Five studies compared the longevity of CRRB versus FRRB, five assessed the clinical performance of CRRBs alone, and 21 studies assessed the clinical performance of FRRBs. There was great variability in study design and the reporting of clinical outcomes, and an analysis and critique of the included papers is provided. Overall, CRRB tend to debond less and hence provide longer-term and more reliable clinical service when compared to FRRB. PRINCIPAL CONCLUSIONS: More high-level, long-term, prospective and clinical controlled trials are required to further analyse and evaluate the long-term outcomes of cast metal-based RRB.