Titanium implants and lateral forces. An experimental study with sheep.

The purpose of this study was to investigate the resistance of titanium implants to horizontal forces in a sheep model. Twenty implants were inserted into the foreheads of 5 sheep, 4 implants on each animal. After a healing period of 3 months, abutments were mounted on the implants. After a further healing period of 3 weeks, the implants were loaded with a horizontal pull of orthodontic elastics. The force varied between 250 and 350 grams. The duration of loading was 3 months. After the loading period the animals were sacrificed and the forehead bones with implants were fixed in formalin and evaluated histologically. In the histological specimens no signs of infection or bone loss were found around the implants. The results of the present study encourage the use of titanium implants also in cases where constant lateral forces are present.