No-prep dentistry using the Simple Orthodontic Extrusion (SOE) technique to create occlusal space. Illustration in tooth wear and resin-bonded bridges

In restorative dentistry, the lack of occlusal space may lead to the mutilation of healthy tissue in order to provide sufficient space for the restorative material. Noprep dentistry can be achieved by placing high-bite restorations, followed by Simple Orthodontic Extrusion (SOE) of other teeth to close the created open bite. This rapid, partial orthodontic treatment is well accepted by patients as it can be easily performed using simple buttons, and it takes only a few weeks to reestablish occlusal contacts. The SOE technique is a further development of the Dahl concept. It has the advantages without the disadvantages. Two applications of this technique are presented in this article: the treatment of the severe wear of anterior teeth with no-prep palatal veneers made of Polymer-infiltrated Ceramic Network (PICN, 'hybrid ceramic') material and the realization of no-prep zirconia resin-bonded bridges (RBBs) to replace missing lateral incisors. An original 3D-printed resin guide for correctly positioning RBBs and facilitating the removal of excess composite cement is also presented. This work highlights the considerable advantages of multidisciplinary collaboration in the field of minimally invasive dentistry.

Posterior two-unit cantilevered zirconia resin-bonded fixed partial dentures: A 3-year prospective single-arm clinical trial.

OBJECTIVES: To evaluate the longevity of cantilevered zirconia-based resin-bonded fixed partial dentures (RBFPDs) in replacing missing posterior teeth, as well as the quality of life and patient satisfaction experienced by those receiving zirconia RBFPDs. METHODS: A prospective single-arm uncontrolled clinical trial was conducted to replace one or more missing premolars or molars with a span of 5 to 8 mm using cantilevered zirconia RBFPDs. Thirty-six participants with 40 prostheses were recruited and underwent a 3-year clinical evaluation. The retainer designs included a minimum thickness of 0.8 mm, a minimum of 200° circumferential wraparound with an occlusal bar, and a connector dimension of 3 × 3 mm. Patient-reported outcomes, including patient satisfaction and Oral Health Impact Profile (OHIP), were assessed. RESULTS: The average age of participants was 45.8 years, and 72.5 % were women. The success rate of the posterior zirconia RBFPDs was 76.2 %, with an estimated mean success duration of 46.1 months. The survival rate was 88.1 %, with an estimated mean survival duration of 49.4 months. Participants were highly satisfied with the treatment, achieving an average satisfaction score of 80.8 ± 11.9. Participants' total OHIP scores decreased from 52.3 to 39.6 after 3 years, indicating a significant improvement in oral health-related quality of life (P = 0.009). CONCLUSIONS: After 3 years, a moderately high survival rate and favourable patient-reported outcomes of posterior cantilevered zirconia RBFPDs were achieved. Therefore, it can be recommended as a conservative treatment option to replace missing posterior teeth, provided that retainer design considerations are taken into account. CLINICAL SIGNIFICANCE: Cantilevered zirconia RBFPDs for posterior teeth can serve as a conservative treatment option that is both aesthetically pleasing and biocompatible. It offers a more cost-effective alternative compared to dental implants, which are often prohibitively expensive for the majority of patients. This approach has the potential to greatly improve patient-reported outcomes.

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.

Failure and complication rates of different materials, designs, and bonding techniques of ceramic cantilever resin-bonded fixed dental prostheses for restoring missing anterior teeth: A systematic review and meta-analysis.

OBJECTIVES: The objective of this review was to assess clinical trials that have examined the materials, design, and bonding of ceramic cantilevered resin-bonded fixed dental prostheses (RBFDPs) as a potential option for replacing missing anterior teeth. The evaluation primarily focuses on the rate of restoration failure and clinical complications. MATERIALS AND METHODS: A thorough search of databases including PubMed/MEDLINE, Scopus, and the Cochrane Library, was conducted. The most recent search was performed in October 2023. Clinical studies that compared ceramic cantilevered RBFDPs with double retainers or cantilevered RBFDPs using different ceramic materials or bonding systems were included. The outcome measures considered were restoration failure and complication rates. RESULTS: Twelve studies met the eligibility criteria. The pooled data showed a statistically significant decrease in complication events when using cantilever designs compared with double retainer designs (p < 0.05); however, there were no differences found between the two designs in terms of restoration failure. The complication and failure rate of cantilever RBFDPs did not show a statistically significant difference with or without ceramic primer application before luting with phosphate monomer-containing luting resin (p > 0.05). CONCLUSIONS: Ceramic cantilevered RBFDPs have lower complication rates compared with those with double retainers. The use of a ceramic primer prior to luting composite resin for ceramic cantilevered RBFDPs decreases the occurrence of complications and failures, although this effect was not statistically significant. Additional research is required to confirm these findings. Glass ceramic cantilever RBFDPs showed a decrease in success after 6 years, requiring ongoing monitoring, but both zirconia and glass-infiltrated alumina cantilever RBFDPs have demonstrated durability with excellent long-term success and survival rates for up to 10 and 15 years. CLINICAL SIGNIFICANCE: Cantilever ceramic RBFDPs in the anterior region are a less invasive and valuable treatment option, providing good esthetic results.

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.

A dual composite resin injection molding technique with 3D-printed flexible indices for biomimetic replacement of a missing mandibular lateral incisor.

PATIENTS: This case report presents a minimally invasive approach to replace a missing mandibular lateral incisor using a dual-injection molding technique with flowable composite resins. Integrated with a comprehensive digital workflow, this method achieves a structurally and esthetically biomimetic, bi-layered prosthetic solution. A 34-year-old woman with congenital absence of a mandibular lateral incisor was successfully rehabilitated using a direct composite resin-bonded fixed partial denture (RBFPD). DISCUSSION: Two specialized three-dimensional (3D)-printed flexible indices stabilized by a custom-designed 3D-printed rigid holder were employed to ensure the meticulous injection molding of flowable composite resins formulated to emulate the inherent chromatic gradations between dentin and enamel. The inherent flexibility of the indices, combined with the holder, facilitated accurate and seamless adaptation to the complex morphological features of the dental arch, thereby mitigating the challenges commonly associated with rigid 3D-printed resin indices. CONCLUSIONS: The bilayered direct composite RBFPD using 3D printed flexible indices prepared with a full digital workflow has several advantages over other dental prosthetic solutions, including noninvasiveness, cost-effectiveness, biomimetic esthetics, repairability, and shortened treatment times. Although the initial results are promising, further longitudinal studies with larger patient cohorts are required to confirm the long-term efficacy of this approach.

Effect of orthodontics combined with fibre-reinforced composite resin-bonded fixed partial denture on anterior dentition defects with minimal vertical intermaxillary space.

BACKGROUND: Prosthodontics are often performed to treat patients with malocclusion and dentition defects. However, single prosthodontics cannot properly correct the disharmony of teeth, dental arch and other parts affected by malocclusion, and some patients may have difficulty in recovering the occlusal function due to poor prosthodontics. OBJECTIVE: This study aims to investigate the effect of orthodontics combined with fibre-reinforced composite resin-bonded fixed partial denture (FRC-RBFPD) on anterior dentition defects with minimal vertical intermaxillary space. METHODS: Sixty-two patients with anterior dentition defects with minimal vertical mandibular space admitted to our hospital between March 2021 and May 2023 were enrolled in this study. The participants were divided into the observation group (31 cases) and the control group (31 cases), according to the treatment plan. The control group was treated with traditional therapy, and the observation group was treated with orthodontic combined FRC-RBFPD therapy. Periodontal conditions (periodontal pocket depth [PD], the plaque index [PLI], the sulcus bleeding index [SBI]), levels of inflammatory factors in gingival crevicular fluid (high mobility group box 1 [HMGB1]), myeloid cell triggering receptor-1 (TREM-1), monocyte chemoattractant protein-1 (MCP-1), pain (visual analogue scale [VAS]), the clinical response rate and the incidence of adverse reactions were collected and compared. RESULTS: After 1, 3, 5 and 9 months following treatment, the scores of the PD, PLI, SBI, HMGB1, VAS, TREM-1 and MCP-1 in the observation group were found to be lower than those in the control group (FPD treatment= 352.532, FPLI score treatment= 112.341, FSBI score treatment= 79.479, FVAS score treatment= 96.132, FHMGB1 treatment= 52.532, FTREM-1 score treatment= 64.593, FMCP-1 score treatment= 53.582, and they were all statistically significant P< 0.05). There was a statistically significant difference in the response rate between the two groups (97.77% vs. 80.65%, χ2= 4.026, P= 0.045). No statistically significant difference was observed in the incidence of adverse reactions between the two groups (6.45% vs. 16.13%, χ2= 1.449, P= 0.229). CONCLUSION: Orthodontics combined with FRC-RBFPD shows an ideal restorative effect on patients with anterior dentition defects and minimal vertical intermaxillary space.

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).

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.

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.

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.