The aim of this study was to perform a photoelastic analysis of stress distribution on straight and angulated implants with different crowns (screwed and cemented). Three models were made of photoelastic resin PL-2: model 1: external hexagon implant 3.75 × 10.00 mm at 0 degrees; model 2: external hexagon implant 3.75 × 10.00 mm at 17 degrees; model 3: external hexagon implant 3.75 × 10.00 mm at 30 degrees. Axial and oblique (45 degrees) load (100 N) was applied with a universal testing machine. The photoelastic fringes on the models were recorded with a digital camera and visualized in a graphic software for qualitative analysis. The axial loading generated the same pattern of stress distribution. The highest stresses were concentrated between medium and apical thirds. The oblique loading generated a similar pattern of stress distribution in the models with similar implant angulation; the highest stress was located on the cervical region opposite to implant angulation and on the apical third. It was concluded that the higher the implant angulation, the higher the stress value, independent of crown type. The screwed prostheses exhibited the highest stress concentration. The oblique load generated higher stress value and concentration than the axial load.
From the Departments of *Dental Materials and Prosthodontics and †Surgery,Araçatuba School of Dentistry, São Paulo State University-UNESP, São Paulo, Brazil.
Received March 25, 2010.
Accepted for publication July 4, 2010.
Address correspondence and reprint requests to Eduardo Piza Pellizzer, DDS, MSc, PhD, Rua José Bonifácio 1193-Vila Mendonça, Postal Code 16015-050, Araçatuba, São Paulo, Brazil; E-mail: firstname.lastname@example.org
Dr. Falcón-Antenucci is a postgraduate student and Drs. Sánchez, Rinaldi, and de Aguirre are students at Araçatuba School of Dentistry, São Paulo State University-UNESP, Brazil.
The authors report no conflicts of interest.