Journal of Oral Implantology October 2013 - (Page 545)

RESEARCH Impression Techniques for Multiple Implants: A Photoelastic Analysis. Part II: Comparison of Four Acrylic Resins ´ Itamar Lopes-Junior, MSc* Barbara de Lima Lucas, MSc Henner Alberto Gomide, PhD Vanderlei Luiz Gomes, PhD Four commercial brands of chemically activated acrylic resin were compared through photoelastic analysis. Photoelastic resin blocks were made with 2 implants placed parallel to each other and 2 square transfer copings splinted. Both transfers were splinted with chemically activated acrylic resin: Dencrilay, Duralay I, Duralay II, and GC. Data were analyzed by 2-way analysis of variance and Tukey test (P , .05). Statistically significant differences were found among the 3 brands of chemically activated acrylic resin. Dencrilay showed greater dimensional alteration. Duralay I and GC are recommended for the transfer of the position of the multi-implants. Key Words: dental implant, impression, photoelasticity, implant-supported prosthesis INTRODUCTION T he main goal of fabricating implantsupported restorations is the production of superstructures that exhibit accurate fit when connected to multiple abutments.1,2 The requisite for obtaining such a fit is a precise impression. The adaptation precision, between prosthetic infrastructure and implant or tooth, is one of the great challenges of the oral rehabilitators. Particularly, the lack of passivity of the prosthetic devices has received great attention from researchers.3–9 Several materials are involved in the execution of adaptation precision, among them, the chemically activated acrylic resin that is used frequently and that is susceptible to dimensional alterations.10,11 Assif et al10 investigated the accuracy of direct implant impression techniques with the use of various splinting materials and found that more Faculty of Dentistry, Federal University of Uberlandia, Uberlandia, Minas Gerais, Brazil. * Corresponding author, e-mail: DOI: 10.1563/AAID-JOI-D-11-00041 accurate results were obtained by using techniques in which chemically activated acrylic resin or impression plaster was used as the splinting material. Hsu et al12 and Herbst et al13 after evaluating the distortion of abutment position on the master cast, concluded that the volume of Duralay acrylic resin used to splint implant transfer copings is an insignificant factor in impression transfer accuracy. However, in the first part of this research report, we show that the resin volume interfered with the transfer process due to the larger amount of resin used. These results are in agreement with those of other studies.14 Del Acqua et al15 compared the dimensional accuracy of 2 impression techniques: Duralay splinted impression copings and metal splinted impression copings for implant-supported prostheses. They used the same impression material, and it was suggested that a more accurate working cast can be fabricated using metal splinted impression copings. Due to the controversial results, this article presents results of a photoelastic analysis comparJournal of Oral Implantology 545

Table of Contents for the Digital Edition of Journal of Oral Implantology October 2013

Food and Drug Administration: Reclassification of Blade Form Dental Implants
Optimizing Platelet-Rich Plasma Gel Formation by Varying Time and Gravitational Forces During Centrifugation
Effect of Surface Roughness and Low-Level Laser Therapy on Removal Torque of Implants Placed in Rat Femurs
Impression Techniques for Multiple Implants: A Photoelastic Analysis. Part I: Comparison of Three Direct Methods
Impression Techniques for Multiple Implants: A Photoelastic Analysis. Part II: Comparison of Four Acrylic Resins
A Pig Model for the Histomorphometric Evaluation of Hard Tissue Around Dental Implants
In Situ Tooth Replica Custom Implant: A 3-Dimensional Finite Element Stress and Strain Analysis
Influence of Different Soft Liners on Stress Distribution in Peri-Implant Bone Tissue During Healing Period. A 3D Finite Element Analysis
Influence of Surface Nano-Roughness on Osseointegration of Zirconia Implants in Rabbit Femur Heads Using Selective Infiltration Etching Technique
Modified Titanium Surfaces Alter Osteogenic Differentiation: A Comparative Microarray- Based Analysis of Human Mesenchymal Cell Response to Commercial Titanium Surfaces
Hemorrhage Secondary to Interforaminal Implant Surgery: Anatomical Considerations and Report of a Case
Rehabilitation of a Patient With Mandibular Resection Using Osteointegrated Implants: A Case Report
Two-Stage Bone Expansion Technique Using Spear-Shaped Implants Associated With Overlapped Flap: A Case Report
Implant Esthetic Restoration in Ridge Deficiencies in Cases of Trauma: A Case Report
Rehabilitation of the Atrophic Maxilla With Tilted Implants: Review of the Literature

Journal of Oral Implantology October 2013