Effect of 50 to 60°C heating on osseointegration of dental implants in dense bone: an in vivo histological study.

OBJECTIVES: To evaluate, in vivo, the effects of bone temperatures increased up to 60°C introduced before implant insertion on titanium implant osseointegration.
MATERIALS AND METHODS: Twenty-four acid etched and sandblasted implants (Cortex Dental Implants) were inserted in the inferior edge of sheep mandibles. Osteotomic sites were randomly divided into 3 groups before inserting the implant. In test 1 group and in test 2 group, implant sites were overheated, respectively, up to 50°C for 1 minute and 60°C for 1 minute, with an electronic controlled probe of 3 mm in diameter and 10 mm in length. Osteotomic sites in control group were not overheated. Implants were inserted according to standard procedures. After 2 months healing, % bone implant contact (%BIC) and infrabony pockets' depth were measured. Unpaired t test was applied to find statistical differences between groups.
RESULTS: No implant failure occurred. No statistical significant difference in %BIC was found among groups. Histological analysis showed that mean infrabony pockets were statistically deeper in 60°C group than in other groups.
CONCLUSIONS: Bone temperature up to 60°C for 1 minute does not seem to significantly impair titanium dental implant osseointegration. Bone damage signs evident in the 60°C group suggest that careful drilling procedure with sufficient irrigation is necessary to avoid periimplant infrabony pockets' formation. More in vivo evaluations are needed to identify what is the value of bone temperature increase for irreversible inhibition of implant osseointegration.