Photoelastic stress analysis in prosthetic implants of different diameters: mini, narrow, standard or wide.
OBJECTIVE
This study investigated the biomechanical behavior of screwed partial fixed prosthesis supported by implants with different diameters (2.5 mm; 3.3 mm and 3.75 mm) by using a photoelastic analysis.


METHODS
Six photoelastic models were fabricated in PL-2 resin as single crowns or splinted 3-unit piece. Models were positioned in a circular polariscope and 100-N axial and oblique (45 degrees) loads were applied in the occlusal surface of the crowns by using a universal testing machine (EMIC). The stresses were photographically recorded and qualitatively analyzed using a software (Adobe Photoshop).


RESULTS
Under axial loading, the number of fringes was inversely proportional to the diameter of the implants in the single crown models. In the splinted 3-unit piece, the 3.75-mm implant promoted lower number of fringes regardless of loading area application. Under oblique loading, a slight increase of fringes number was observed for all groups.


CONCLUSIONS
The standard implant diameter promoted better stress distribution than the narrow and mini diameter implants. Additionally, the splinted crowns showed a more uniform stress distribution.
Adjunct Professor, Department of Dental Materials and Prosthodontics, Araçatuba School of Dentistry, São Paulo State University -UNESP, Araçatuba, São Paulo, Brazil .
Marcelo
M
Coelho Goiato
Associate Professor, Department of Dental Materials and Prosthodontics, Araçatuba School of Dentistry, São Paulo State University-UNESP , Araçatuba, São Paulo, Brazil .
Alves Aldiéris
AA
Pesqueira
Associate Professor, Department of Dental Materials and Prosthodontics, Araçatuba Dental School, UNESP , Araçatuba, São Paulo, Brazil .
Daniela Micheline Dos
DM
Santos
Adjunct Professor, Federal University of Department of Dental Materials and Prosthodontics , Alfenas - UNIFAL .
Marcela Filié
MF
Haddad
Post-Graduate Student, Department of Dental Materials and Prosthodontics, Araçatuba School of Dentistry, São Paulo State University-UNESP , Araçatuba, São Paulo, Brazil .
Amália
A
Moreno
Biomechanical; Dental implantation; Dental stress analysis