Journal of Oral Implantology April 2014 - (Page 161)

RESEARCH Finite Element Analysis of Provisional Structures of Implant-Supported Complete Prostheses Bruno Albuquerque Carneiro, DDS, MS Rui Barbosa de Brito Jr, DDS, MS, PhD Fabiana Mantovani Gomes Franca, DDS, MS, PhD* ¸ The use of provisional resin implant-supported complete dentures is a fast and safe procedure to restore mastication and esthetics of patients soon after surgery and during the adaptation phase to the new denture. This study assessed stress distribution of provisional implant-supported fixed dentures and the all-on-4 concept using self-curing acrylic resin (Tempron) and bis-acrylic resin (Luxatemp) to simulate functional loads through the three-dimensional finite element method. Solidworks software was used to build three-dimensional models using acrylic resin (Tempron, model A) and bis-acrylic resin (Luxatemp, model B) for denture captions. Two loading patterns were applied on each model: (1) right unilateral axial loading of 150 N on the occlusal surfaces of posterior teeth and (2) oblique loading vector of 150 N at 458. The results showed that higher stress was found on the bone crest below oblique load application with a maximum value of 187.57 MPa on model A and 167.45 MPa on model B. It was concluded that model B improved stress distribution on the denture compared with model A. Key Words: finite element analysis, all-on-4, resin provisional prosthesis INTRODUCTION T he most common complications for the Branemark protocol, such as peri-implant bone loss, implant fracture, bar fracture close to the most distal implants, loosening, fracture of prosthetic screws and implant failure due to loss of osseointegration, are related to the most distal implants near the suspended elements. The all-on-4 concept (Nobel Biocare, Gothenburg, Sweden), a variation of the Branemark protocol, uses longer and inclined distal implants to reduce the distal cantilever of implantsupported prostheses, thereby reducing flexural strength of the structure and, consequently, overload on implants.1 Implant-supported prostheses fabricated of resin were used in some studies on immediate implant loading,2,3 but the laboratory phase was not ˜ ˜ Sao Leopoldo Mandic School of Dentistry, Campinas, Sao Paulo, Brazil. * Corresponding author, e-mail: biagomes@yahoo.com DOI: 10.1563/AAID-JOI-D-11-00188 conducted to fabricate the metal bars. Some authors used complete removable prostheses and converted them into an implant-supported structure by adding resin to the internal part.4,5 In some cases of immediate loading, resin has some advantages over other materials because it is easier to work with it and costs less. Bis-acrylic resin shows higher values of resistance to tensile, compressive, and flexural forces and elasticity than acrylic resin. In addition, it is easy to apply because the self-mixing application system significantly reduces clinical time compared with the bonding technique using cylinders and incremental application of acrylic resin with a paint brush.6 Another advantage is the flexibility of the material, which favors adaptation of dentures that present distortions. It is also easy to fabricate, substitute and repair. Acrylization without a supporting structure is the fastest and most economical provisional treatment. The short time between the patient's rehabilitation and delivery of the prosthesis lowers the cost of clinical time.6 Finite element analysis has been used to study the properties of materials and Journal of Oral Implantology 161

Table of Contents for the Digital Edition of Journal of Oral Implantology April 2014

Consolidated Standards of Reporting Trials (CONSORT): Answering the Call for JOI’s Endorsement
Photoelastic Analysis of Stress Distribution With Different Implant Systems
Influence of Abutment Screw Design and Surface Coating on the Bending Flexural Strength of the Implant Set
Comparison of Implant-Abutment Interface Misfits After Casting and Soldering Procedures
Evaluation of Accuracy of Casts of Multiple Internal Connection Implant Prosthesis Obtained From Different Impression Materials and Techniques: An In Vitro Study
The Effect of Different Implant-Abutment Connections on Screw Joint Stability
Effects of pH and Elevated Glucose Levels on the Electrochemical Behavior of Dental Implants
Finite Element Analysis of Provisional Structures of Implant-Supported Complete Prostheses
Saliva Versus Peri-implant Inflammation: Quantification of IL-1b in Partially and Totally Edentulous Patients
Heat Generated During Seating of Dental Implant Fixtures
An Alternative Approach for Augmenting the Anterior Maxilla Using Autogenous Free Gingival Bone Graft for Implant Retained Prosthesis
Nasopalatine Duct Cyst, a Delayed Complication to Successful Dental Implant Placement: Diagnosis and Surgical Management
The Custom Endosteal Implant: Histology and Case Report of a Retrieved Maxillary Custom Osseous-Integrated Implant Nine Years in Service
Occlusal Concepts Application in Resolving Implant Prosthetic Failure: Case Report
Three-Year Follow-Up of a Single Immediate Implant Placed in an Infected Area: A New Approach for Harvesting Autogenous Symphysis Graft
Use of Stress Analysis Methods to Evaluate the Biomechanics of Oral Rehabilitation With Implants

Journal of Oral Implantology April 2014