Influence of retainer design and number of inlay boxes on the biomechanical behavior of zirconia cantilever resin bonded fixed dental prosthesis.

OBJECTIVES: The development of dental adhesives with enhanced bond strength has assisted minimally invasive dentistry. The aim of this study was to evaluate the fracture load and stress distribution pattern of two retainer designs for posterior cantilever resin bonded fixed dental protheses (RBFDPs). MATERIALS AND METHODS: Forty human mandibular molars were divided into two groups according to the retainer design; lingual coverage (LC) and occlusal coverage (OC) retainers. Each main group was then divided according to the number of inlay boxes (n = 10); one inlay and two inlay boxes. High translucency (3Y) zirconia was used to manufacture all restorations, and a dual-polymerizing adhesive resin cement was used for bonding. All specimens underwent 10,000 cycles of thermocycling (5-55°C), 240,000 cycles of dynamic loading (50 N, descending speed v = 30 mm/second, frequency = 1.6 Hz), and failure load test. Both one-way and two-way ANOVA tests were used to analyze the data. The four models included in the in-vitro study are part of the finite element analysis (FEA). When the restorations failed, maximal principal stress values on restorations, enamel, dentin, and luting resin were investigated. RESULTS: A statistically significant (p = 0.018) higher failure load was recorded for OC1 (627.00 ± 153.4 N) than the other groups; (548.0 ± 75.6 N, 521.20 ± 11.3 N, and 509.20 ± 14.9 N for LC1, LC2, and OC2, respectively). With regard to failure mode, one inlay box designs showed more favorable failure pattern than those of two inlay boxes. FEA showed higher stress magnitude transmitted to the tooth structure in models LC2 and OC2. CONCLUSIONS: Lingual coverage and occlusal coverage retainers are promising designs capable to withstand the normal occlusal force for cantilever RBFDP in premolar area. The use of two inlay boxes decreased the fracture load of the two retainer designs and increased the stress transmitted to the tooth and resulted in high incidence of catastrophic failure. CLINICAL SIGNIFICANCE: Monolithic high translucent zirconia RBFDP could be considered as a viable treatment option to substitute missing posterior tooth, with improved esthetics and biocompatibility.

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.

Biomechanical behavior of posterior metal-free cantilever fixed dental prostheses: effect of material and retainer design.

OBJECTIVE: To study the fracture resistance and stress distribution pattern of translucent zirconia and fiber-reinforced composite cantilever resin-bonded fixed dental prostheses (RPFDPs) with two retainer designs. MATERIALS AND METHODS: Forty human mandibular molars were divided into two groups according to the retainer design. The restorations included a premolar pontic and 2 retainer designs: (D1) inlay ring retainer and (D2) lingual coverage retainer. Each main group was then divided according to the material used (n = 10): zirconia (Z) or fiber-reinforced composite (FRC) (F). Restorations were cemented using dual polymerizing adhesive luting resin. All specimens were thermo-cycled (5-55 °C for 10,000 cycles), then subjected to dynamic loading (50 N, 240,000, and 1.6 Hz) and fracture resistance test. The finite element analysis includes the two models of retainer designs used in the in vitro test. Modified von Mises stress values on enamel, dentin, luting resin, and restorations were examined when the restorations failed. RESULTS: A significantly higher failure load was recorded for zirconia groups (505.00 ± 61.50 and 548.00 ± 75.63 N for D1Z and D2Z, respectively) than for FRC groups (345.00 ± 42.33 and 375.10 ± 53.62 N for D1F and D2F, respectively) (P = 0.001). With regard to failure mode, D2 showed a more favorable failure pattern than D1. Model D2 resulted in lower stresses in tooth structure than model D1, and zirconia transmitted more stresses to the tooth structure than FRC. CONCLUSIONS: The lingual coverage retainer (D2) enhanced the biomechanical performance of the restoration/tooth complex. Considering the failure mode and tooth stress, FRC is a promising treatment option when constructing a cantilever RPFDP. CLINICAL RELEVANCE: Dentists should be aware of the biomechanical behavior during the selection of the material and for the replacement of a single missing mandibular premolar tooth with minimally invasive RBFDP.

Conservatively replacing missing anterior teeth with resin bonded ceramic restorations.

OBJECTIVE: This article describes improvements in materials and adhesion technologies that have facilitated new, minimally invasive treatment for the replacement of missing anterior teeth. CLINICAL CONSIDERATIONS: In the first of two case reports presented, the treatment of a 13-year-old female patient with a missing right lateral mandibular incisor is described. The patient was told she could not have an implant placed until she was 25 years of age and space post orthodontics was inadequate for implant placement. Treatment options included: a provisional removable appliance (flipper), an Essix appliance, or a resin-bonded one-wing lithium disilicate bridge with only slight modification to the right central incisor and a lingual wing on the canine. The second case report describes an adult female patient who had an impacted maxillary left canine that could not be pulled into position and wanted a replacement for the missing No. 11. This article demonstrates how the use a two-abutment bridge consisting of an inlay in the first premolar and a lingual wing with a proximal retention groove and a vertical path of insertion is a viable alternative to an implant or a conventional bridge to replace a maxillary canine with minimal removal of tooth structure. CONCLUSION: With the advent of new ceramic materials and improved adhesion minimally invasive prosthesis can be fabricated to replace missing teeth in the esthetic zone. Usually, one wing with a zirconia framework is recommended but Lithium disilicate can also be used depending on occlusal forces. CLINICAL SIGNIFICANCE: Resin-bonded fixed dental prostheses (RBFDPs) can be used on occasion as a viable alternative to implants but case selection and adherence to appropriate adhesive techniques are key to longevity.

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.

Evaluation of Bond Strength of Cantilever Resin-retained Bridge Designs: An In Vitro Study.

AIM: The aim of the study was to compare the bond strength of three cantilever resin-bonded bridge (RBB) designs cemented with resin cements. MATERIALS AND METHODS: Twenty-four extracted human mandibular canines with eight teeth per group were used in this study to evaluate the bond strength of cantilever resin-retained bridge designs of the mesh, perforated, and combination of mesh and perforated luted to the prepared lingual surface of canine teeth using resin cement. Debonding was done using Instron universal testing machine by applying load on the mid-buccal region of the pontic and the obtained values were evaluated. The data was analyzed statistically. RESULTS: The mean shear bond strengths of mesh, perforated, and combination of mesh and perforated are 0.88 ± 0.31 MPa, 0.81 ± 0.31 MPa, and 0.93 ± 0.32 MPa. However, there is no significant differences in the statistical analysis that were performed using a one-factor analysis of variant (ANOVA) test (p = 0.744). CONCLUSION: Within the limitation of this study for cantilever resin-retained bridge designs, the combination of mesh and perforated design showed greater mean shear bond values when compared with the mesh design and perforated designs. This shows equal in vitro performance to the gold standard designs (group A is mesh design and group B is perforated design). CLINICAL SIGNIFICANCE: The new design which is the combination of mesh and perforated shows equal in vitro performance to the gold standard designs. Thus, their use in clinical situation can bring better result in concern to cantilever resin-retained prosthesis.

Effect of captopril pretreatment on the dentin bonding durability of self-etch adhesive.

To investigate the effect of captopril on the dentin bonding durability of self-etch adhesive. Different concentrations of captopril ethanol solutions or captopril ethanol/water solutions were prepared to pretreat dentin as primer for the self-etch adhesives. The surface morphology of the dentin was observed with scanning electron microscopy (SEM). Based on the morphology analysis, the pretreatment condition was selected and two self-etch adhesives were employed to evaluate the improvement effect of the captopril pretreatment on the dentin bonding durability. : SEM showed that the pretreatment of captopril ethanol solutions and captopril ethanol/water solutions were able to remove the smear lay and partially expose collagen matrix. According to the SEM results, the pretreating condition of captopril ethanol/water solution with the pretreating time of was selected for further dentin bonding study. For Clearfil SEBOND system, the immediate bonding strength increased from to  (<0.05). After one-year aging, the bonding strength of the control group decreased markedly [(22.90±6.82) MPa, <0.05]; while the bonding strength of the captopril pretreated group kept steadily >0.05]. For Clearfil S BOND system, there was no significant difference in the immediate bonding strength between the experimental group [(4.07) MPa] and the control group[(4.11) MPa]. But after one-year aging, the bonding strength of the experimental group was higher than that of the control group <0.05]. : The pretreatment with captopril ethanol/water solution increases the dentin bonding strength of the self-etch adhesive systems and also improves the bonding durability.

Influence of the preparation form on the retention of resin-bonded attachments for removable dental prostheses.

OBJECTIVES: The study evaluated the influence of the number of retention grooves and the retainer wing thickness on the retention of resin-bonded attachments (RBAs). METHODS: Overall, 64 extracted human teeth were prepared, whereby the number of retention grooves (4, 2, 1, or no grooves) and the material thickness (0.7 or 0.5 mm) of the RBAs were varied. This resulted in eight groups with eight specimens each. A sample size of eight specimens per group was chosen because the chewing simulator used for dynamic loading can load eight specimens at a time. After the size of the adhesive area was determined, the abutment teeth were provided with RBAs and subjected to a dynamic loading with thermal cycling. Finally, the failure load was examined using a retention test. RESULTS: The mean failure loads ranged from 152 ± 50 N to 228 ± 32 N. There had been a significant interaction between the two main factors, i.e., number of retention grooves and material thickness. Neither the number of retention grooves nor the size of the adhesive area had a significant influence on the failure load. CONCLUSIONS: Using a reduced number of retention grooves seems reasonable. However, clinical considerations suggest using two retention grooves to simplify the preparation and bonding procedures. CLINICAL RELEVANCE: The retention of resin-bonded attachments is promising and supports the clinical application of this minimally invasive treatment modality.

Replacement of a missing molar despite proximal undercuts by using two single-retainer resin-bonded fixed dental prostheses.

AIM: The aim of this case report is to present the minimally invasive replacement of a missing molar in the presence of considerable proximal undercuts of the adjacent abutment teeth. The use of two single-retainer resin-bonded fixed dental prostheses (RBFDPs) made this therapy possible. MATERIALS AND METHODS: A missing mandibular right first molar required replacement. Two single-retainer RBFDPs were digitally designed in the shape of half a molar each and were milled using CAD/CAM from monolithic 3Y-TZP zirconia ceramic. The posterior RBFDP portion retained by the second molar was designed in the pontic contact area to create a common path of insertion for the anterior RBFDP portion with the distal surface of the second premolar. A slight interlocking between the proximal contact surfaces of the two pontics was designed to prevent future migration between the split restorations. Precise placement of the two RBFDPs during adhesive luting was ensured with the aid of a positioning splint. RESULTS: The patient was recalled after 10 months and was very satisfied with the minimally invasive molar replacement. CONCLUSION: Using two single-retainer RBFDPs to replace a molar in a split design enables a minimally invasive posterior tooth replacement despite considerable proximal undercuts of the adjacent abutment teeth.

Influence of attachment design and material on the retention of resin-bonded attachments.

OBJECTIVES: The purpose of this laboratory study was to evaluate the influence of the attachment design and material on the retention of resin-bonded attachments (RBAs) before and after dynamic loading. MATERIALS AND METHODS: Forty-eight caries-free human premolars were prepared for RBAs fabricated either from a CoCr alloy or from zirconia ceramic. Specimens were divided into three groups (n = 16 each). Two groups had a standard attachment design for alloys (group M made from a CoCr alloy and group Z1 made from zirconia ceramic). The third group had an attachment design optimized for zirconia ceramic (group Z2 made from zirconia ceramic). Attachments were bonded to the acid-etched enamel of the premolars using a phosphate monomer containing adhesive resin. Subgroups of eight specimens each were either debonded using a tensile force in a universal testing machine at a cross-head speed of 2 mm/min (S) or were exposed to dynamic loading with 50 N over 1200,000 loading cycles in a chewing simulator prior to debonding (D). RESULTS: There were no significant differences in the initial failure loads of groups. With the exception of subgroup Z1-D, all specimens survived the dynamic loading. Statistical analysis showed that dynamic loading caused a significant decrease of failure loads in group Z1. In contrast, subgroup Z2-D exhibited significantly higher failure loads compared to the subgroup Z1-D. CONCLUSIONS: The results suggest that zirconia RBAs fabricated with an optimized attachment design may be a valid clinical alternative to metal RBAs. CLINICAL RELEVANCE: Clinical data on the long-term potential of zirconia RBAs is required before these restorations can be recommended for general use.

Five-year success rate of resin-bonded fixed partial dentures: A systematic review.

OBJECTIVES: To assess and compare the 5-year success rate of resin-bonded fixed partial dentures (RBFPDs) fabricated from different materials. METHODS: An electronic search on 3 databases from January 1965 to March of 2017 was done for human randomized clinical trials (RCTs), and prospective and retrospective cohort studies. The key words used in the search were: Bridge OR bridges OR fixed partial OR fixed dental AND resin bonded OR Maryland OR ceramic bonded. Quality assessment was done using the Newcastle-Ottawa scale. Success was defined as the RBFPDs remaining in situ and not having experienced debonding, biological failures, or mechanical failures at the examination visit. RESULTS: Meta analyses of the included studies showed an estimated 5-year success rate of 88.18% for the metal framework RBFPDs and 84.41% for the nonmetal framework RBFPDs. The estimated 5-year success rate for each nonmetal material category was 92.07% for zirconia, 94.26% for In-Ceram alumina, and 84.83% for fiber-reinforced composite. The failure rate was not statistically significant among the single, double, and multiple retainers RBFPDs (P > .05). Technical complications were the main reason for failures. CONCLUSION: The 5-year clinical performance of RBFPDs is similar to the performance of conventional fixed partial dentures (FPDs) and implant-supported crowns. CLINICAL SIGNIFICANCE: Clinicians should consider using RBFPDs more often because their clinical performance is similar to the performance of conventional FPDs and implant-supported crowns.

The treatment dilemma of missing maxillary lateral incisors-Part I: Canine substitution and resin-bonded fixed dental prostheses.

OBJECTIVE: Clinicians are faced with three common treatment options for the high frequency of missing or lost maxillary lateral incisors; canine substitution, a resin-bonded fixed dental prosthesis (RBFDP), or a dental implant. A review of current data and guidelines for treatment provide new insight into making the most appropriate selection. OVERVIEW: The incidence of maxillary incisor agenesis and loss is prevalent. Both canine substitution and RBFDPs exhibit esthetic and functional advantages and disadvantages. CONCLUSIONS: Most missing lateral incisors are detected at an early age as a result of congenital absence; therefore, proper treatment of these young patients is essential. Both canine substitution and RBFDPs can provide long-term success and esthetics when carefully executed. The decision should be based on the patient's expectations, their clinical presentation, cost, and the team's ability to provide the best long-term esthetic and functional prognosis for a specific patient. CLINICAL SIGNIFICANCE: Patients regularly present for treatment of missing and lost maxillary lateral incisors. The functional and esthetic aspects of canine substitution and a RBFDP should be clearly understood relative to the clinical parameters of each patient prior to treatment.

Agenesis of a maxillary lateral incisor associated with bilateral canine inclusions: A noninvasive multidisciplinary approach.

OBJECTIVE: The treatment of congenitally missing maxillary lateral incisors is often complex and requires a multidisciplinary approach, which demands continuous collaboration among the different specialists involved in the rehabilitation. In young patients, implant therapy or the preparation of intact teeth for fixed prostheses is not indicated. CLINICAL CONSIDERATIONS: Two complex cases of double maxillary canine inclusion were treated with combined surgical, orthodontic, and conservative prosthetic treatments. Orthodontic therapy allowed the creation of the necessary interocclusal space to fabricate the all-ceramic resin-bonded fixed partial dentures without the preparation of the abutment teeth. CONCLUSIONS: Carefully planned and meticulously executed orthodontic and prosthetic therapies allowed for a noninvasive rehabilitation of patients with maxillary lateral incisor agenesis. CLINICAL SIGNIFICANCE: This article provides clinicians with a noninvasive solution for agenesis of lateral incisors associated with canine inclusions. Indications for the choice of material of all-ceramic resin-bonded fixed partial dentures are discussed and presented.

PEEK High Performance Polymers: A Review of Properties and Clinical Applications in Prosthodontics and Restorative Dentistry.

Various materials have been used over time in prosthetic dentistry. However, due to the evolution of science and knowledge, new materials are being brought to the forefront. Polyether ether ketone (PEEK) is a polymer with many potential applications in dentistry. The use of PEEK has become increasingly more common in dental practice; its favorable properties have made it a compelling alternative biomaterial in restorative dentistry. The current trend is moving towards the use of metal-free restorations and biomaterials which exhibit advanced properties in the complex oral environment. This review paper presents and summarizes clinical applications of PEEK in contemporary dentistry.

A low cost minimally invasive adhesive alternative for maxillary central incisor replacement.

OBJECTIVE: The beneficial mechanical properties of zirconia, together with the adhesive techniques, provide a wide range of clinical applications, including the construction of thin structures and minimally invasive adhesive restorations. CLINICAL CONSIDERATIONS: A periodontal disease-related missing maxillary central incisor, in a pregnant patient with chronic periodontal disease in the first trimester of pregnancy, and with type II diabetes treated with resin-bonded fixed partial denture using the missing tooth cemented to a zirconia framework and then bonded to the abutment teeth. CONCLUSIONS: According to the systemic conditions presented in this case report, using a low-cost technology and the missing tooth it was possible to obtain an easier and satisfactory esthetic and functional result. CLINICAL SIGNIFICANCE: The mechanical properties of zirconia made it possible to treat a pregnant patient with chronic periodontal disease in the first trimester of pregnancy, and with type II diabetes with a thin zirconia framework and minimally invasive adhesive restorations.

Clinical procedures, designs, and survival rates of all-ceramic resin-bonded fixed dental prostheses in the anterior region: A systematic review.

OBJECTIVES: The aim of this study is to systematically review all the clinical articles about all-ceramic resin-bonded fixed dental prosthesis (RBFDP) in the anterior region and assess their designs, clinical procedures, and survival rates. A systematic review was conducted after searching electronic databases PubMed/Medline and EBSCOhost Research Databases for articles published in English between 1987 and July 2017. MATERIALS AND METHODS: The inclusion criteria were selected as all clinical studies, original design clinical reports, and clinical reports (follow-up time more than 1 year) as all clinical information in the literature are desired to be included in the present review. RESULTS: The initial electronic search generated 472 articles from PubMed/Medline and 464 articles from EBSCOhost Research Databases. After selection of the articles as per the inclusion criteria, a final sample of 29 original studies is decided as: 1 randomized controlled clinical trial, 4 clinical controlled trials, 4 prospective cohort studies, 2 retrospective cohort studies, 6 original design clinical reports, and 12 clinical reports. After evaluation of the selected articles, it is likely that cantilever design all-ceramic RBFDPs are more successful than two retainer design in the anterior region; however, there is limited evidence for this result in the literature. CONCLUSION: Well-designed randomized controlled clinical trials with large sample size are still needed to achieve more accurate results about the clinical success rate of different RBFDPs designs in the anterior region. CLINICAL SIGNIFICANCE: Indications, designs, abutment teeth preparation, provisionalization, try-in, surface treatment options, and cementation of the all-ceramic resin-bonded fixed dental prostheses are described in this article. Clinical survival rates are also given in detail, so that clinicians can easily compare the current studies and give their own decision about all-ceramic resin-bonded fixed dental prostheses in the anterior region.

A Systematic Review of the Survival and Complication Rates of All-Ceramic Resin-Bonded Fixed Dental Prostheses.

PURPOSE: The aim of this systematic review was to investigate the survival and complication rates of all-ceramic resin-bonded fixed dental prostheses (RBFDPs). MATERIALS AND METHODS: The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were applied. A systematic search was conducted by an electronic search in PubMed, EMBASE, Cochrane Library, and CNKI databases complemented by a manual search. Only clinical studies on all-ceramic RBFDPs with a mean follow-up period of at least 3 years qualified for data analyses. RESULTS: Among 1503 screened articles, one randomized controlled trial (RCT) and seven prospective or retrospective cohort studies were included in this study. The estimated 5-year survival rate of all-ceramic RBFDPs was 91.2%. Debonding and framework fracture were the two most frequent technical complications, and the estimated 5-year debonding rate and fracture rate were 12.2% and 4.8%, respectively. Additionally, cantilevered all-ceramic RBFDPs had a higher survival rate (p < 0.01), lower debonding rate, (p < 0.05), and fracture rate (p < 0.01) compared with two-retainer all-ceramic RBFDPs. Zirconia ceramic RBFDPs had a lower incidence of failure but a higher debonding rate compared with glass-ceramic RBFDPs (p < 0.01). CONCLUSION: Within the limitations of this systematic review, although all-ceramic RBFDPs have a favorable 5-year survival rate, this rate cannot represent the complete success of the treatment, since it may include typical complications such as debonding and fractures. There is an urgent need for long-term clinical studies, especially for well-designed RCTs on all-ceramic RBFDPs.

Clinical Evaluation of All Ceramic Zirconia Framework Resin Bonded Bridges.

OBJECTIVE: To evaluate the clinical longevity of 58 adhesively bonded single unit yttria-stabilized tetragonal zirconia polycrystalline (Y-TZP) ceramic Resin Bonded Bridges (RBB). MATERIALS AND METHODS: Twenty six consecutive patients with at least one congenitally missing tooth in the maxilla or mandible were provided with 58 single unit Y-TZP RBBs. The cantilever RBBs were designed and milled using a CAD-CAM system to produce frameworks which were veneered using a glass-ceramic material and cemented with a self-etching dual-cure resin cement. RESULTS: Following a mean follow up period of 36.2 months (maximum 62.3 months, minimum 25.4 months), 48 restorations remain in service with a survival rate of 82.7%. One anterior retainer fracture was encountered and no fractures of the posterior framework or ceramic were noted within the time frame reported. CONCLUSIONS: All ceramic Y-TZP RBBs replacing maxillary and mandibular teeth in the anterior and posterior areas demonstrated an 82.7% Kaplan Meier survival rate over 3 years, which was comparable to previously published survival rates for the non-perforated metal framework RBBs. CLINICAL IMPLICATIONS: Replacement of anterior or posterior teeth using single unit cantilevered RBBs using Y-TZP ceramics should be considered a viable restorative option with a high survival rate.

Effect of different framework materials of resin-bonded bridges on load to fracture values and stress distribution.

PURPOSE: The aim of this study was to compare in vitro fracture strengths (FSs) of metal- and fiber-reinforced frameworks of resin-bonded bridges and to evaluate stress distribution with finite element analysis (FEA). MATERIALS AND METHODS: Totally 80 extracted maxillary central and maxillary canine teeth were used for in vitro part of this study as two groups; metal-reinforced framework (n = 20) [(metal-supported resin-bonded bridge (MR-RB)] and fiber-reinforced frameworks (n = 20) [fiber-reinforced resin-bonded bridge (FR-RB) were prepared for three unit resin-bonded bridges. All bridges were loaded from lateral pontic at 1 mm/min crosshead speed and fracture values were recorded. Mann-Whitney U-test was used for statistical analysis, and fracture patterns were evaluated visually. FEA was carried out in the second part of the study, and stress distribution of MR-RB and FR-RB structures was analyzed using one of the models from in vitro specimens as main model. RESULTS: The mean FSs of MR-RB and FR-RB were 637.47 ± 151.91 N and 224.86 ± 80.97 N, respectively. Fiber-reinforced specimens were found to distribute stress more homogeneous and connectors in each framework were the regions where stress concentrated mostly. CONCLUSION: In vitro FSs of MR-RB and the stress concentration of the point that the forces were applied were higher as compared to other parts of the restoration. Furthermore, in contrast to FR-RB specimens, retainer tooth fractures were observed in MR-RB specimens.

6-mm-long implants loaded with fiber-reinforced composite resin-bonded fixed prostheses (FRCRBFDPs). A 5-year prospective study.

AIM: To evaluate the clinical and radiographic outcomes and the survival rates of fiber-reinforced composite resin-bonded fixed prostheses (FRCRBFDPs) placed in the posterior area supported by two short (6 mm) implants. MATERIALS AND METHODS: Twenty consecutive patients received 40 SLActive 6-mm-long implants with a diameter of 4.1 mm (n = 29) or 4.8 mm (n = 11). Insertion torques and RFA (Resonance Frequency Analysis) were measured at implant installation. The prosthetic rehabilitation was performed after 8 weeks from insertion with a screw-retained two- or three-unit fixed dental prosthesis fabricated of FRCRBFDPs. Implant survival rates and marginal bone levels were evaluated at various time intervals until 5 years after loading. RESULTS: Two of 20 patients lost four implants supporting two FRCRBFDPs between the second and the third year of follow-up (cumulative survival rate: 90% after 5 years). Four patients suffered a fracture of the prosthetic reconstruction, and the success rate of the rehabilitation was 70% after 5 years. A mean marginal bone loss of 0.30 ± 0.34 mm was found after 5 years of function at the remaining implants. CONCLUSION: The survival of short implants was 90% owing to two bridges losses in the maxilla. However, the success rate of FRCRBFDPs over 5 years was only at 70%.