Journal of Oral Implantology April 2014 - (Page 117)

RESEARCH Photoelastic Analysis of Stress Distribution With Different Implant Systems Eduardo Piza Pellizzer, DDS, MSc, PhD* Rafael Imai Carli, DDS ´ Rosse Mary Falcon-Antenucci, DDS, MSc, PhD Fellippo Ramos Verri, DDS, MSc, PhD Marcelo Coelho Goiato, DDS, MSc, PhD Luiz Marcelo Ribeiro Villa, DDS, MSc, PhD The aim of this study was to evaluate stress distribution with different implant systems through photoelasticity. Five models were fabricated with photoelastic resin PL-2. Each model was composed of a block of photoelastic resin (10 3 40 3 45 mm) with an implant and a healing abutment: model 1, internal hexagon implant (4.0 3 10 ˜ ˜ mm; Conect AR, Conexao, Sao Paulo, Brazil); model 2, Morse taper/internal octagon implant (4.1 3 10 mm; ˜ Standard, Straumann ITI, Andover, Mass); model 3, Morse taper implant (4.0 3 10 mm; AR Morse, Conexao); model 4, locking taper implant (4.0 3 11 mm; Bicon, Boston, Mass); model 5, external hexagon implant (4.0 3 10 ˜ mm; Master Screw, Conexao). Axial and oblique load (458) of 150 N were applied by a universal testing machine (EMIC-DL 3000), and a circular polariscope was used to visualize the stress. The results were photographed and analyzed qualitatively using Adobe Photoshop software. For the axial load, the greatest stress concentration was exhibited in the cervical and apical thirds. However, the highest number of isochromatic fringes was observed in the implant apex and in the cervical adjacent to the load direction in all models for the oblique load. Model 2 (Morse taper, internal octagon, Straumann ITI) presented the lowest stress concentration, while model 5 ˜ (external hexagon, Master Screw, Conexao) exhibited the greatest stress. It was concluded that Morse taper implants presented a more favorable stress distribution among the test groups. The external hexagon implant showed the highest stress concentration. Oblique load generated the highest stress in all models analyzed. Key Words: dental implant, implant systems, biomechanics, photoelasticity INTRODUCTION A factor that affects rehabilitation with osseointegrated implants is the manner in which stresses are transferred to the surrounding bone, and much will depend on the design of the implant, type of connection implant/abutment, the presence or absence of threads, micro architecture, and chemical composition of the implant surface.1-4 Thus, the aim of the functional designs is to direct the loads through a better distribution of forces, Department of Dental Materials and Prosthodontics, Aracatuba ¸ ˜ Dental School, Sao Paulo State University, Brazil. * Corresponding author, e-mail: ed.pl@uol.com.br DOI: 10.1563/AAID-JOI-D-11-00138 optimizing the function of prostheses supported with implants.5 Actually, there are many implant designs available. The evolution has been by way of incremental changes in size, shape, materials, and surfaces of earlier designs, prompted, at times, by market demands rather than basic science research.1,6 From a bioengineering perspective, an important issue is to design the implant with a geometry that will minimize the peak bone stress caused by standard loading.7 Another factor that affects the distribution of stresses on the implant-bone interface is the connection type; thus research on different methodologies has demonstrated the superiority of the internal connection when compared with the Journal of Oral Implantology 117

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