Resin-bonded Fixed Partial Dentures Research Articles

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

To generate data on the long-term survival of metal-ceramic resin-bonded fixed partial dentures (RBFPDs). 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. 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. 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.

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). 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. 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.

Terminology focused on design and retention methods used for anterior resin-bonded fixed partial dentures in English literature: A scoping review

PurposeNovel terms describing several designs of resin-bonded fixed partial dentures (RBFPDs) continue to appear. Indeed, a variety of terms are used in the English scientific literature The use of a standard terminology is important for a fair and efficient understanding. This study aimed to investigate if the terminology used to describe designs and retention methods for anterior RBFPDs is standard. MethodsAn electronic search in the English literature was conducted in PubMed/Medline to identify all publications reporting RBFPDs in the anterior region until August 2022. This search was completed by hand searching. Terms indicating different designs of RBFPDs were listed and then classified. Percentages of their use were calculated to determine the commonly used terms. Analysis of the use of these terms was performed based on the standards determined by the latest edition of the Glossary of Prosthodontic Terms (GPT). The impacts of the MeSH Thesaurus and GPT on the nomenclature used for RBFPDs was assessed. ResultsA total of 125 articles were eligible for this review. In the retained articles, 86 terms were found. Among them, thirty-nine terms were classified into three groups. Only six terms were defined in the latest edition of GPT (GPT-9). Several classified terms that are commonly used were not identified in the GPT-9. Conversely to the GPT-9 which impact was insignificant, the MeSH Thesaurus had an important impact on the nomenclature used for RBFPDs. ConclusionThe terminology used to describe designs and retention methods for anterior RBFPDs was non-standard. The GPT-9, constituting an important reference, defined a limited number of terms related to RBFPDs and had no significant impact on the standardization of the terminology used for RBFPDs. Efforts should therefore be continued to standardize the terminology. A specialized mini-glossary grouping and defining all the terms found in this study will helpful in clarifying the terminology used for the anterior RBFPDs.

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

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. 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 50µm alumina particles (Group 1); abrasion with 30µm silica-coated alumina particles (Group 2); abrasion with silica-coated alumina particles (30µm) and silane application (Group 3); abrasion with silica-coated alumina particles (30µm) and 10-methacryloyloxydecyl dihydrogen phosphate (10-MDP) primer application (Group 4); abrasion with silica-coated alumina particles (30µm) 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 2min per cycle and then mechanical cyclic loading with 1200,000 cycles of 50N at a 1.7Hz frequency at an angle of 135° to the abutment's long axis. Then, RBFPDs were loaded to fracture using a universal testing machine at 1mm/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. Mean fracture load results showed a statistically significant difference between the research groups (p<0.0001) and it ranged from 69.78 to 584N. 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. Abrasion of zirconia surface with 30µm 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 Success Rate of the Adhesive Partial Fixed Prosthesis after Five Years: A Systematic Review

Objective: Evaluation of the success and/or survival rates of resin-bonded fixed partial dentures (RBFPDs) reported in the scientific literature with a minimum average observation time of five years. Materials and Methods: Search conducted in Pubmed, Web of Science, and Cochrane databases in free-text format and MESH terms, until May 2021. The random-effects model was used for the estimated survival rate, percentage per year of estimated failure, and existing complications for the meta-analysis. Study heterogeneity was assessed by the inconsistency test (I2) and study quality by the Downs and Black scale. Results: Eleven articles were included, with 687 participants and 783 RBFPDs, with a mean observation time of 8.2 years, with success rates mentioned in three articles and survival rates reported in nine articles. A total of 142 failures were reported for 783 prostheses, the most frequent being debonding. The estimated failure rate was between 0.53% and 5.10% per year. The studies were of sufficient quality. In the meta-analysis, the survival rates showed a significant result (p &lt; 0.001), with moderate heterogeneity (I2 = 58.76%). Conclusions: Within the limitations of this research, mainly related to the heterogeneity of the studies and their quality, it seems possible to conclude that RBFPDs are a viable clinical option for the rehabilitation of patients with single edentulous spaces, mainly when using a single retainer and a zirconia-ceramic prosthesis.

Comparative Evaluation of Stress Acting on Abutment, Bone, and Connector of Different Designs of Acid-Etched Resin-Bonded Fixed Partial Dentures: Finite Element Analysis.

Background: Finite element analysis (FEA) is one of the best methods for evaluating the stress distribution of restorations, such as fixed partial dentures. The development of resin cement has transformed prosthesis bonding and retention properties. Resin-bonded fixed partial dentures (RBFPD) have been considered minimally invasive treatment options for the prosthetic rehabilitation of single missing teeth. Objectives: The aim of this study was to evaluate the stress load and distribution in four different designs of acid-etched RBFPDs using FEA. Materials and Methods: The designs included standard tooth preparation principles and additional features. The first premolar and first molar abutments replaced the missing second premolar. Designs 1, 2, 3, and 4 included (1) lingual wings and occlusal rests; (2) wings and proximal slices; (3) wings, rests, and grooves; and (4) wings, rests, grooves, and occlusal coverage. The prepared models were restored with RBFPDs. A load of 100 N was applied to the central groove of the pontic to simulate occlusal forces. The materials used in the models were considered to be isotropic, homogeneous, and linearly elastic. FEA was used to reveal stresses acting on the abutment, bone, and connector in all prosthesis designs. Results: The stresses transmitted to the abutment and bones were lowest for design 3, using wings, rests, and grooves. The stresses acting on the connector were the weakest in design 2. The stresses transmitted to the abutment and bone were highest in designs 1 and 4. The stresses transmitted to the connector were highest in design 3. Conclusion: The wings, rests, and grooves design is possibly the ideal and conservative tooth preparation design to receive a posterior RBFPD. This design transmits less stress to the abutments and less bone resorption in the FEA. It is most likely to be successful in the clinical provision and ensures the longevity of the prosthesis.

ЛАБОРАТОРНОЕ ИЗУЧЕНИЕ АДГЕЗИВНЫХ МОСТОВИДНЫХ ПРОТЕЗОВ В БОКОВЫХ ОТДЕЛАХ ЗУБНЫХ РЯДОВ. ЧАСТЬ 2. МЕХАНИЧЕСКИЙ ЭКСПЕРИМЕНТ

Background. To date, numerous retrospective studies on the use of resin-bonded fixed partial dentures (RBFPD) have proven their reliability. Nevertheless, there are still questions about the design of posterior resin-bonded fixed partial dentures for replacing 1 and 2 missing teeth.&#x0D; Objectives. The present research was an in vitro study of the fracture strength of resin-bonded fixed partial dentures (RBFPD) with movable connector on the heat-pressed ceramic minor retainer when replacing 1 or 2 missing premolars. &#x0D; Methods. The laboratory research was carried out to study the fracture strength of fixed/movable RBFPD on acrylic moulds with a space equivalent to one or two premolars. The nature of RBFPD destruction and breaking loads in newtons were assessed by comparing the mean values according to the t-test. We studied 4 groups of RBFPD, depending on the type of retainer and the number of lost teeth.&#x0D; Results. The smallest fracture strength (1017.0 ± 49.0 N) was observed in the group with two missing teeth. In groups with 1mm thick occlusal rest, its deformation was observed. In the groups with 2 mm thick occlusal rest, partial fracture of the ceramic minor retainer was observed. Fixation loss of the adhesive wings or cast crowns as a large retainer was not observed. &#x0D; Conclusions. Fixed/movable RBFPD replacing two missing premolars are less fracture resisted then when replacing one missing premolar. Fixation loss of the large retainers was not observed. Adhesive wings were as effective as cast crowns as a large retainer.

Maximum fracture load and stress concentration in resin-bonded fixed partial dentures of indirect composite resin reinforced by silica-nylon mesh

Objectives: This study aimed to evaluate the maximum fracture load using a silica-nylon reinforcement system on resin-bonded fixed partial dentures (RBFPD) made of indirect composite resin. Methods: An in vitro test simulated an anterior (A) and posterior (P) three-element RBFPD. Thus, 80 specimens were made in 8 experimental groups (n = 10). The groups were divided according to the silica-nylon reinforcement presence (R) and aging (C). The aging process was performed through mechanical cycling for 106 cycles at 4 Hz. The samples were tested by maximum fracture load in a universal testing machine with a 1000 Kgf load cell and analyzed by Stereomicroscope and Scanning Electron Microscopy (SEM). Statistical analysis consisted of analysis of variance (two-way ANOVA) and Tukey test 5%. An in silico study was performed by Finite Element Analysis (FEA), in which the abutment teeth and the prostheses were scanned and transferred to CAD Rhinoceros (version 4.0SR8; McNeel North America, Seattle, WA) for 3D modeling. The analysis test was performed in computer aided engineering software (ANSYS 19.3, Canonsburg, PA, USA). Results: The maximum fracture load results (N) were A=163.55; AC=184.48; AR=198.81; ARC=192.24; P=539.99; PC=359.61; PR=541.74 and PRC=608.74. The Maximum Principal Stress results obtained in the FEA were (MPa): A=53.24/122.40; AR=55.07/117.70; P=33.28/36.18 and PR=28.06/42.87. Significance. It was concluded that the presence of the silica-nylon mesh increased the maximum fracture load of the RBFPD without increasing the stress concentration, regardless of the prosthesis design.

Comparitive Evaluation of Inlay Retained and Surface Retained Resin Bonded Fixed Partial Dentures

Objective: The objective of the study was to evaluate and compare the clinical success rate of inlay and surface retained RB-FPDs fabricated with fiber reinforced composite. Material and Methods: This study was performed in Prosthodontic department de`Montmorency college of dentistry. 172 RB-FPDs were completed with two preparation designs having 86 cases in each design (inlay retained and surface retained). Restorations were done on patients for single missing molar surrounded by sound, healthy and well aligned abutments. RB-FPDs were fabricated in zirconium silicate based indirect composite (ceramage) with incorporation of glass fibers (Everstick C&amp;B). Follow up was done after every six months till 18 months. Complications (fracture, debonding, and dislodgment or abutment tooth caries) developed during follow up were recorded and analyzed through SPSS version 17. Results: Overall success rate of 76.9% was observed in both designs of RB-FPDs. P value of 0.190 showed insignificant statistical differences in success rate of two designs however there was a trend towards better performance of inlay retained RBFPDs. Fracture of the framework was most prevalent mode of failure followed by debonding of the restoration. Conclusion: The fiber reinforced RB-FPD is a viable treatment option for replacement of single missing posterior tooth. Keywords: Maryland Bridge, Resin bonded bridges, Resin bonded fixed partial dentures (RBFPDs), Minimum preparation bridges

Pragmatic approach to rehabilitate maxillary teeth in aesthetic zone using resin bonded FDP- A case report

Resin bonded fixed dental prosthesis offers most conservative and cost-effective option with missing teeth in aesthetic zone specially when an implant prosthesis is not indicated. This case report describes a treatment option for the replacement of a missing maxillary central incisor using a double-retainer resin-bonded fixed partial denture (RBFPD), fabricated from zirconium dioxide (ZrO) ceramic. No clinical complications were observed at follow-up examination after placement of the prosthesis. Satisfactory functional and aesthetic results were achieved. A treatment modality using a ZrO ceramic RBFPD is an alternative for single anterior tooth replacement.

A retrospective comparison of the survival of vital teeth adjacent to single, bounded edentulous spaces rehabilitated using implant-supported, resin-bonded, and conventional fixed dental prostheses

ObjectivesIn this study, we aimed to compare the long-term survival of vital teeth adjacent to bounded edentulous spaces rehabilitated using an implant-supported prosthesis (ISP), a resin-bonded fixed partial denture (RBFPD), or a conventional fixed partial denture (CFPD). The risk factors for complications in teeth adjacent to the edentulous space (TAES) were also investigated. MethodsWe followed-up a consecutive series of 514 patients who underwent rehabilitation of a single bounded edentulous space with vital TAES (ISP: 103; RBFPD: 216; and CFPD: 195) from 2008 to 2017. Cumulative survival rates of prosthesis and TAES, and complication-free rates of TAES, were evaluated using the Kaplan−Meier analysis and log-rank test. Risk factors were evaluated using a Cox proportional hazards model. ResultsCumulative complication-free rates of TAES showed no significant differences among the three groups. The cumulative survival rate of TAES in CFPD was significantly lower than that of ISP (p = 0.037); no significant differences were observed between ISP and RBFPD (p = 0.513), and RBFPD and CFPD (p = 0.076). Older age (p = 0.027) was the only independent significant risk factor for complications in TAES. Installation of CFPD (p = 0.019), ceramic prosthesis in edentulous space (p = 0.026), and deeper periodontal probing depth (p = 0.018) of TAES were significant risk factors for non-surviving TAES. ConclusionsRehabilitating a single bounded edentulous space with CFPD could increase the risk for TAES loss compared with ISP. Risk of TAES loss remained similar between ISP and RBFPD, which can minimize the loss of coronal tooth structure during tooth preparation. Clinical SignificanceTeeth adjacent to edentulous space show equivalent longevity when rehabilitating a single bounded edentulous space with resin-bonded fixed partial dentures or single standing implant-supported prosthesis, at least 10 years post-installation.

Influence of Resin Cement Thickness and Elastic Modulus on the Stress Distribution of Zirconium Dioxide Inlay-Bridge: 3D Finite Element Analysis

The mechanical properties and the thickness of the resin cement agents used for bonding inlay bridges can modify the clinical performance of the restoration such as debonding or prosthetic materials fracture. Thus, the aim of this study was to evaluate the stress distribution and the maximum strain generated by resin cements with different elastic moduli and thicknesses used to cement resin-bonded fixed partial denture (RBFPD). A three-dimensional (3D) finite element analysis (FEA) was used, and a 3D model was created based on a Cone-Beam Computed Tomography system (CBCT). The model was analyzed by the Ansys software. The model fixation occurred at the root of the abutment teeth and an axial load of 300 N was applied on the occlusal surface of the pontic. The highest stress value was observed for the Variolink 0.4 group (1.76 × 106 Pa), while the lowest was noted for the Panavia 0.2 group (1.07 × 106 Pa). Furthermore, the highest total deformation value was found for the Variolink 0.2 group (3.36 × 10−4 m), while the lowest was observed for the Panavia 0.4 group (2.33 × 10−4 m). By means of this FEA, 0.2 mm layer Panavia F2.0 seemed to exhibit a more favorable stress distribution when used for cementation of posterior zirconium-dioxide-based RBFPD. However, both studied materials possessed clinically acceptable properties.

Longevity of resin-bonded fixed partial dentures made of metal alloys: A review of the literature.

Purpose In this review, we evaluate the survival rate of resin-bonded fixed partial dentures (RBFPDs) made of metal alloys.Methods An electronic search of English peer-reviewed dental literature on PubMed was conducted to identify all publications reporting on RBFPDs made of metal alloys until March 2019. The searched keywords were: bridge OR fixed partial denture OR fixed prosthesis OR fixed prostheses AND resin bonded AND metal OR alloy AND survival OR longevity (RBFPD was not included). Furthermore, the "Related Articles" feature of PubMed was used to identify further references of interest during the primary search. A definitive list of articles was screened to extract qualitative data after the application of the inclusion and exclusion criteria, and the results were analyzed.Results Overall, 977 publications were found through an electronic and manual search, out of which 130 articles were selected after screening based on title and abstract. A total of 52 publications passed the second review phase after assessment for eligibility, from which 24 studies were excluded after full-text screening. Finally, a total of 28 studies were selected.Conclusions The survival rate of RBFPDs differed greatly depending on the type of metal alloy, adhesion system, and observation period assessed, e.g. the 10-year survival rate ranged from 18% to 88%. The wide range of survival rates of the RBFPDs reported indicates that though RBFPD is a reliable prosthesis, it is prone to failure if some processes are not completed.

Clinical Performance of Posterior Inlay-Retained and Wing-Retained Monolithic Zirconia Resin-Bonded Fixed Partial Dentures: Stage One Results of a Randomized Controlled Trial.

To prospectively compare the clinical performance of posterior inlay-retained and wing-retained monolithic zirconia fixed partial dentures (FPDs). After simple randomization, 30 participants received either one inlay-retained (n = 15; mean age: 56.38 ± 12.70 years; 10 men [66.7%]) or one wing-retained (n = 15; mean age: 45.90 ±13.24 years; 7 men [46.7%]) FPD. The restorations, which predominantly replaced first molars, were fabricated from translucent, 3mol% yttria-stabilized zirconia and attached with self-etching resin cement. Restorations and abutment teeth were clinically followed up for complications one week and 3, 6, and 12 months after cementation. Plaque and gingival scores, probing pocket depths, and attachment levels were recorded for the abutment and contralateral reference teeth both before treatment and during follow-up examinations. The restorations were also assessed in accordance with FDI World Dental Federation criteria. Statistical analyses were conducted with R (α = 0.05). An adaptive, 2-stage study design based on the incidence of failure-free survival in the groups after 12 months (stage 1) was implemented. Predefined decision rules were used to determine whether further recruitment (stage 2) would enable the detection of a statistically significant difference between the restoration designs with sufficient power. During 12 months, only one wing retainer debonded which required removal of the FPD. Failure-free survival was thus 93.3% for wing-retained and 100% for inlay-retained FPDs (log-rank test, p = 0.317). Moderate aftercare resulted in intervention-free rates of 78.8% and 86.7% for inlay-retained and wing-retained restorations, respectively (log-rank test, p = 0.605). Based on FDI World Dental Federation criteria, all restorations were acceptable at the 12-month follow-up (Fisher-Boschloo test, p = 0.161). Plaque, gingival, and periodontal scores remained practically unchanged from before treatment to the 12-month follow-up. Recruitment was stopped after stage 1 because, based on the small difference in the incidence of failure-free survival in the groups, it was accepted that it would not be possible to recruit the necessary number of participants to show a statistically significant difference between the retainer designs. Both inlay-retained and wing-retained monolithic zirconia resin-bonded FPDs performed well for the 12-month, short-term follow-up period.

Resin Template for Guiding Preparation in Resin Bonded Fixed Partial Denture – A Case Report

Resin Bonded Fixed Partial Denture (RBFPD)&nbsp; is a popular treatment for tooth preservation. Mechanical retention is crucial for RBFPD, where debonding is the main cause of failure. RBFPD preparation is minimally invasive. It removes undercut and tooth structure that supports retention so that a single insertion guide was achieved. This preparation is achieved by using surveyor on the diagnostic cast, but there is a concern on how to copy the surveyed cast to intraoral. Resin template method as a preparation guide was useful to avoid excessive tooth removal. RBFPD design was marked by using pencil on the diagnostic cast. The cast was surveyed to get the preparation designed and prepared by using milling device surveyor and burs. The template was made on the cast. The separator was applied and the resin template was built along the margin until the occlusal line angle. The abutment teeth were etched and bonded. Bonding procedure was done on the template. The template was placed on the teeth and polymerized. Abutment teeth preparation were done according to the cast with the bur contact simultaneously with the template’s margin and finishing line. Resin templates have advantages compared to silicone and vacuum form template. Silicone template is thicker and harder to detect the preparation margin. Vacuum form template was less adaptive because of space and step. Resin template has better accuration and adaptation, easier made and efficient also prevent excessive tooth removal and control the preparation, mechanical retention can be achieved for RBFPD restoration longevity. Resin template is useful because preparation can be transferred from diagnostic cast to intraoral accurately.

Clinical evaluation of resin - bonded bridges

This study evaluated resin-bonded fixed partial dentures (FPDs) clinically. Forty patients received 40 resin-bonded FPDs. Two types of luting materials were used, Super Bond Crown and Bridge Material and Degufill SC composite. The metal frame works for Super Bond Crown and Bridge Material were sandblasted only, and for Degufill SC composite were electrolytically etched, Clinical evaluation were performed at 3, 6, 12 and 24 months after cementation. None of the prostheses bonded by Super Bond Crown and Bridge Material lost retention, whereas two of the acid etched retainers required replacement after one year, Resin bonded prostheses appear to be favorable alternative to other types of fixed partial dentures.

Bond strength evaluation of inlay-retained resin-bonded fixed partial dentures with two different cavity designs and two different adhesive systems: In vitro study

Background/Aim: The purpose of this in-vitro study was to compare the resin-bonded fixed partial dentures (RBFPD) fabricated using two different structural designs and two different antibacterial adhesive lutting protocols in regard to their resistance to debonding. Material and Methods: Forty samples for a model with single missing molar were divided into 4 groups (M1, M2, C1, C2) (n=10). M1 and M2 were prepared in accordance with modified inlay slot-cavity retained RBFPD design; C1 and C2 were prepared according to conventional inlay slot-cavity retained RBFPD design. M1 and C1 cavities were treated with 2% chlorhexidine-based (CHX) cavity disinfectant and 10-methacryloyloxydecyl dihydrogen phosphate (MDP) containing adhesive system; M2 and C2 cavities were treated with MDP and 12-methacryloyloxydodecylpyridinium bromide (MDPB) containing adhesive system featuring antibacterial cavity cleansing effect. The RBFPDs were made of base-metal alloy and their fit surfaces sandblasted with aluminium oxide (Al2O3). Adhesive resin cement was used for cementation, and the RBFPD retainers were interlocked into their corresponding inlay cavities using composite resin. After 1 week being immersed in aqueous environment, the RBFPDs were subjected to tensile loading at a crosshead speed of 1 mm/min until failure. One way ANOVA and Tukey HSD tests were used for statistical evaluation (a=0.05). Mode of failure and tooth damage was also noted. Results: Mean tensile bond strength values were 356 N for M1, 305 N for M2, 467 N for C1, and 455 N for C2. Tensile strength values of C1 and C2 were significantly higher than those of M1 and M2 (p&lt;0.05). The mode of failure was mostly adhesive in character at the metal-cement interface in all groups. Tooth fracture was observed nearly in all specimens. No significant difference was detected between the antibacterial adhesive lutting protocols (p&gt;0.05). Conclusions: The RBFPDs with the conventional design were found to be more retentive than those with the modified design. Using an adhesive system featuring antibacterial properties with no need of separate antibacterial agent application during bonding may be favourable.

Ten-year clinical evaluation of posterior fixed-movable resin-bonded fixed partial dentures

ObjectivesTwo-unit cantilevered resin-bonded fixed partial dentures (RBFPDs) offer long-term retention for anterior and premolar-sized spans. At this center, molar and longer spans have been restored with fixed-movable (FM) RBFPDs to overcome the lower retention rates of fixed-fixed RBFPDs. This retrospective study aimed to evaluate the long-term longevity and the patient-reported outcomes of posterior FM-RBFPDs. MethodsPosterior FM-RBFPDs that had been inserted at least five years were reviewed. Survival was “retention of the original prosthesis in mouth” and success was “survival of prosthesis and absence of complications requiring treatment intervention”. Prosthesis location, number of units, insertion year, tooth/teeth replaced and operator experience were collected. Patients’ acceptance to FM-RBFPDs were assessed using prosthesis satisfaction questionnaire and Oral Health Impact Profile (OHIP-49). Results were analyzed using log-rank and cox-regression tests at significance level α = 0.05. ResultsOne-hundred-and-one prostheses were examined. The mean observation time was 126.4 ± 32.2 months. Thirty-six (35.6%) and 63 (62.4%) FM-RBFPDs were rated as success and survival respectively. Prostheses inserted after year 2001 (n = 69) experienced 42.0% (n = 29) success and 75.4% (n = 52) survival, and its survival rate was significantly better than those inserted in or before 2001 (p = 0.01). Five- and ten-year cumulative survival probability of FM-RBFPDs inserted after year 2001 were 82.3% and 74.1% respectively. The most frequent complications were debonding among 34 (33.7%) prostheses. Patients’ acceptance were high. ConclusionsMore recently inserted prostheses showed improved longevity and patients’ acceptance to posterior FM-RBFPDs were high. Clinical significanceFix-Movable RBFPDs are a viable tooth replacement option in the posterior region.

All-ceramic premolar guiding plate retains resin-bonded fixed partial dentures

This study aims to investigate the fracture resistance and short-term restorative effects of resin-bonded fixed partial dentures (RBFPDs) made from heat-pressed lithium-disilicate-based glass-ceramic (IPS e.max press) and zirconia ceramic (WIELAND) and retained by all-ceramic guiding plates when used to restore missing mandibular second premolars. A total of 64 human mandibular first premolars and first molars were prepared as abutments, then were randomly divided into 4 groups (n=8): E0, heat-pressed ceramic RBFPDs, no cyclic loading; E1, heat-pressed ceramic RBFPDs exposed to 300 000 cycles of dynamic loading; W0, zirconia ceramic RBFPDs, no cyclic loading; and W1, zirconia ceramic RBFPDs exposed to 300 000 cycles of dynamic loading. Fracture strength was tested in a universal testing machine. The medians of fracture strength were 1 242.85 N±260.11 N (E0), 1 650.85 N±206.77 N (W0), 1 062.60 N±179.98 N (E1), and 1 167.61 N±265.50 N (W1). Statistical analysis showed that all the groups exhibited significantly higher fracture strength compared with the maximum bite force in the premolar region (360 N; P<0.001). The W0 group had significantly higher fracture strength than the E0 group (P<0.05). Meanwhile, no significant difference in fracture strength was observed between the E1 and W1 groups (P>0.05). Significant statistical differences were found between the zirconia ceramic groups (W0 and W1, P<0.05) but not between the glassceramic groups (E0 and E1, P>0.05) after dynamic loading. The RBFPDs retained by all-ceramic guiding plates exhibited promising fracture properties and optimal short-term restorative effects when used to restore missing mandibular second premolars.

Influence of resin cement rigidity on the stress distribution of resin-bonded fixed partial dentures

The mechanical properties of the adhesive cement used in resin-bonded fixed partial dentures (RBFPD) can modify the clinical performance of the rehabilitation. The goal of this study was to evaluate the influence of the elastic modulus of different cements on the stress distribution in RBFPD using finite element analysis. For that an anterior 3-unit prosthesis was modeled based in a stereolithography file. The model was meshed with tetrahedral elements and materials considered isotropic, linearly elastic and homogeneous. The force applied to the palatal area of the lateral incisor (pontic) at 45° was 100 N. The cements used presented 7 different elastic modulus (E): 2, 6, 10, 14, 18, 22 or 26 GPa. The total deformation, von-Mises stress and maximum principal stress criteria were used to calculate the results. The lower tensile stress occurred in the cement layer with E = 2 GPa [25.6 (canine) and 16.32 MPa (incisor)]. For the prosthesis, the model with the lower tensile stress [287 (canine) and 248 MPa (incisor)] occurred when the cement presented E = 26 GPa.In this way, the stress concentration may have its magnitude modified depending on the stiffness of the cement. Since more flexible cements concentrate less tensile stress in its structure, but allow an increased displacement of the prosthesis, which is friable and rigid and ends up concentrating more tensile stress at its connector. In that way the clinician should avoid the use of adhesive cement with lower elastic modulus due to it increases the stress concentration in the ceramic.