The Use of All-Ceramic Resin-Bonded Bridges in the Anterior Aesthetic Zone

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.

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

Purpose

Novel 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.

Methods

An 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.

Results

A 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.

Conclusion

The 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.

Replacement of Congenitally Missing Maxillary Lateral Incisor with Two-Buccal-Retainer Resin-Bonded Fixed Dental Prosthesis Modified by Proximal Boxes

A 21-year-old male patient with congenitally missing maxillary right lateral incisor presented to Fixed Prosthodontics Department at the Faculty of Dentistry, Damascus University (Damascus, Syria). A two-buccal-retainer lithium disilicate glass-ceramic resin-bonded fixed dental prosthesis (RBFDP) was chosen to replace the missing tooth. This clinical report describes a novel preparation design of two-buccal-retainer lithium disilicate glass-ceramic RBFDP modified by proximal boxes. A recall appointment after 3 years showed no fracture, no de-bonding, no secondary caries, and no staining in prosthesis margins. Color matching with natural teeth was excellent, and the patient was satisfied.

Do you know your ceramics? Part 4: alumina

Alumina is a well-known dental ceramic material that has made waves within the dental industry for its good aesthetics and strength when compared to older materials for fixed prostheses, such as crown and bridgework. To be able to confidently use this material, a clinician should understand the physical and optical properties so as to know why and how this material might work in various clinical settings. This part of the ceramic series aims to explore the various alumina-based ceramic systems available on the market and discuss their properties, applications and indications. We also intend to briefly describe the preparation design requirements and cementation protocol for this type of ceramic.

Improving Esthetics of Removable Partial Dentures Using Palatal Retentive Arms

A well-designed removable partial denture can replace the loss of hard and soft tissues, restore masticatory function and maintain arch integrity. It is relatively simple, non-invasive and economical compared to other treatment options. Removable partial denture is therefore a common option among various treatment replacing missing teeth. A removable partial denture replacing anterior missing teeth can improve esthetics and hence the patient’s quality of life. However, metal components of a removable partial denture may be visible and affects patient satisfaction. Esthetics of a removable partial denture can often be improved with some modifications to traditional designs. This article reported the use of a cobalt-chromium-based removable partial denture to replace a missing maxillary lateral incisor and molars. Palatal retentive arms were employed as the retentive components on the premolars to avoid the metal component being seen when speaking and smiling. The indications and design of the removable partial dentures with palatal retentive arms are also discussed.

Combined Orthodontic and Restorative Minimally Invasive Approach to Diastema and Morphology Management in the Esthetic Area. Clinical Multidisciplinary Case Report with 3-Year Follow-Up

Introduction

Ceramic laminates are restorations that are bonded using adhesive techniques, which provide for the treatment of the prepared dental elements according to well-defined steps. Adhesive cementation guarantees high predictability and esthetics. Orthodontic treatment is the first choice in patients with a dental misalignment. Patients who have dental element color and shape issues will undergo restorative treatment following orthodontics. Case Report. This clinical report describes a case treated with an interdisciplinary approach (orthodontic and prosthetic) of a patient who presented with diastemas, inversion of dental axes, small clinical crowns, and chromatic imperfections in the anterior maxillary teeth. The esthetic expectations of the patient for the anterior portion of the maxillary anterior teeth have been successfully achieved through orthodontic treatment and the realization of ceramic veneers. An accurate interdisciplinary evaluation of the treatment was necessary for a satisfactory result in the anterior maxillary teeth esthetically compromised in several aspects. Discussion. The modern materials used with the strict protocol of the adhesive procedures allow a minimally invasive, highly esthetic approach with an excellent long-term prognosis. The restorations must reproduce the physiological characteristics of the natural teeth aiming at an excellent biological, biomechanical, functional, and esthetic integration. Many adult patients come to visit with a combination of problems; the esthetic rehabilitation of these cases requires the evaluation of the quantity of gingival exposure, of the gingival architecture, of the size of the clinical crowns, and of the dental position. The ideal treatment of these cases involves an interdisciplinary approach. Prosthodontists, periodontists, orthodontists, and dental technicians must work together because the understanding of the various phases of treatment is fundamental to achieve the desired clinical result.

Conclusion

The coordinated treatment of the orthodontist, periodontist, and prosthodontist, with careful consideration of the expectations and requests of patients, was fundamental for the success and satisfaction of the patient.

Fracture strength of lithium disilicate cantilever resin bonded fixed dental prosthesis

OBJECTIVES

Metal and Zirconia cantilever resin bonded fixed dental prosthesis (RBFDPs) are extensively used when missing anterior teeth. Lithium disilicate is not used a lot as it is not indicated by the manufacturers. The aim of this in vitro study was to investigate the fracture strength of lithium disilicate cantilever RBFDPs with different configurations and compare them to metal and zirconium RBFDPs.

METHODS

Sound extracted human canines (N = 60) were divided into six groups, to be restored with a cantilever RBFDP. Specimen were randomly divided over 6 groups (n = 10): Full crown of lithium disilicate (FCL); Veneer wing of lithium disilicate (VL); Connector of lithium disilicate (CL); Palatal wing of lithium disilicate (PL); Palatal wing of zirconia (PZ) and Palatal wing of metal ceramic (PM). All bridges were bonded with an adhesive system. After thermalcyclic ageing (20 × 10³x, 5-55 °C) all samples were loaded until fracture occurred. Failure types were classified and representative SEM done.

RESULTS

The mean fracture strength results per group were: 588N (FCL) 588N (PM), 550N (CL), 534N (PL), 465N (VL), 38N (PZ). A significant (p = 0.001) difference was found between the groups, all groups had a higher fracture strength than the zirconia RBFDPs. Failure type analysis showed some trends among the groups. Irrepairable fractures of the root were only seen in samples restored with lithium disilicate. Metal and zirconia RBFDPs predominantly failed on the adhesive interface, where 60% of the zirconia samples had pretest debondings.

SIGNIFICANCE

No differences in fracture strength were found between cantilever RBFDPs made from metal or lithium disilicate. Metal (0% pre-test failures) and zirconium (60% pretest failures) RBFDPs failed predominantly on the adhesive interface whereas the lithium disilicate (0% pre-test failures) samples showed fractures in the contact area. The least invasive connector (CL) and Metal (PM) RBFDP obtained a high fracture strength and optimal fracture pattern.

Short communication: Influence of retainer configuration and loading direction on the stress distribution of lithium disilicate resin-bonded fixed dental prostheses: 3D finite element analysis

The present study elucidates the mechanical performance of different designs of resin-bonded fixed dental prostheses made of lithium disilicate simulating masticatory loads of anterior or canine guidance. A three-dimensional model of maxilla was constructed containing central incisor and canine teeth, with edentulous space of the lateral incisor. Three designs of prosthesis were created: retained in central incisor (1-I), retained in canine (1-C) and fixed in both teeth (2-IC). The computational analysis was performed for load in canine and central incisor separately (100N, 45°). The tensile and shear stresses were calculated for the resin-bonded fixed dental prosthesis, bonding surface of each retainer and cement layer using 3D finite element analysis. The 20 highest stress values were analyzed using two-way ANOVA and post-hoc Tukey test, all with α = 5%. The computational analysis showed that 2-retainer resin-bonded fixed dental prosthesis presented the worst prognosis regardless of the mandibular movement. ANOVA showed that Mandibular movement*Retainer interaction influenced on the tensile and shear stresses values (p < 0.01). Higher stresses were observed in the connector region for all groups (13-82.2 MPa; 11-70.2 MPa). In order to reduce the stress concentration in the resin-bonded fixed dental prosthesis and the retainer made of lithium disilicate, the occlusion may serve as the selection criteria of the unitary abutment for better sustainability.