Implant design and interface force transfer. A photoelastic and strain-gauge analysis.

Implant design and interface force transfer. A photoelastic and strain-gauge analysis.
Cehreli M, Duyck J, De Cooman M, Puers R, Naert I.
2004 Apr
PubMed
Department of Prosthetic Dentistry, BIOMAT Research Group, Catholic University of Leuven, Belgium.
OBJECTIVES: To compare stress and strain magnitudes of butt-joint and internal-cone oral implants in a bone simulant. MATERIAL AND METHODS: Photoelastic and strain-gauged models of solitary Branemark, ITI and Astra Tech implants were obtained. Vertical and 20 degrees oblique forces of 100 and 150 N were applied on the abutments in separate load cases. Isochromatic fringe patterns around implants were observed and photographed in the field of a polariscope. Strain-gauge measurements were performed and principal strains induced around implants were calculated. RESULTS: Isochromatic fringe orders of all designs were similar under both loading conditions (P>0.05). Strains around Branemark implants were lower than around Astra Tech and ITI implants, particularly under vertical loads. The latter implants had similar strain magnitudes (P>0.05), although strains around the conical Astra Tech implant were lower under vertical load. CONCLUSIONS: Butt-joint and internal-cone oral implants have similar force distribution characteristics. The implant-abutment mating design is not a decisive factor affecting stress and strain magnitudes in a bone simulant.