N L Clelland1, A Gilat. 1. Ohio State University College of Dentistry, Columbus.
Abstract
PURPOSE: This investigation compared the stress production characteristics of five abutment angulations for a specific implant system. MATERIALS AND METHODS: Photoelastic resin was cast directly to a 3.75 x 10-mm Branemark fixture (Nobelpharma USA, Inc, Chicago, IL) in a 50 x 70 x 13-mm mold. A strain gauge rosette was also incorporated in the resin to allow precise determination of normal stresses at a specific point. Each 4-mm abutment (15 degrees, 25 degrees, and 35 degrees from Implant Innovations (West Palm Beach, FL) and 0 degree and 30 degrees from Nobelpharma) was assembled on the fixture, subjected to 178N load, and viewed with a circular polariscope. Observed fringes were photographed and strain indicator readings were recorded. RESULTS: Mean observed fringe order and mean principle stress and strain at the location of the rosette were determined. CONCLUSION: At the location of the rosette, all five of the abutments produced principal strains (compressive and tensile) within the physiological zone for bone. The rosette was located approximately 4 mm away from the fixture. Higher stresses and strains can be expected in regions closer to the implant.
PURPOSE: This investigation compared the stress production characteristics of five abutment angulations for a specific implant system. MATERIALS AND METHODS: Photoelastic resin was cast directly to a 3.75 x 10-mm Branemark fixture (Nobelpharma USA, Inc, Chicago, IL) in a 50 x 70 x 13-mm mold. A strain gauge rosette was also incorporated in the resin to allow precise determination of normal stresses at a specific point. Each 4-mm abutment (15 degrees, 25 degrees, and 35 degrees from Implant Innovations (West Palm Beach, FL) and 0 degree and 30 degrees from Nobelpharma) was assembled on the fixture, subjected to 178N load, and viewed with a circular polariscope. Observed fringes were photographed and strain indicator readings were recorded. RESULTS: Mean observed fringe order and mean principle stress and strain at the location of the rosette were determined. CONCLUSION: At the location of the rosette, all five of the abutments produced principal strains (compressive and tensile) within the physiological zone for bone. The rosette was located approximately 4 mm away from the fixture. Higher stresses and strains can be expected in regions closer to the implant.