Stress and strain distribution in the bone surrounding a new design of dental implant: a comparison with a threaded Branemark type implant.

The stress and strain distributions in the bone surrounding a new dental implant, designed specifically for use with a bioactive porous coating and thus having a fully bonded interface to the bone, have been analysed. The new implant geometry was slightly tapered, with deep concentric grooves to allow bone ingrowth and load transfer, and had a parallel cylindrical section at the neck. The results have been compared with stress and strain predictions in the bone surrounding a 'Branemark type' threaded implant with a fully bonded interface. Under axial loading both implant types produced similar stress and strain distributions with a higher level of stress in the cortical bone surrounding the neck of the implant. Under lateral loading a high stress concentration was found in the neck region of both implants, but this was lower around the neck of the new design compared with the threaded implant. When the new implant was surrounded by cancellous bone, the reduction in the stress concentration was up to 50 per cent. This reduction should help to reduce fatigue failure and bone resorption in this area under lateral loading.