The use of thermal imaging to assess heat generation during dental implant bed preparation in the presence of a surgical guide with an incorporated coolant channel

PURPOSE: This study evaluates the thermodynamic benefits of including an irrigation fluid channel in the design of surgical guides used for dental implant site drilling. MATERIALS AND METHODS: Two types of guides suitable for hosting artificial bone plates that mimic the mechanical properties of human alveolar bone were designed: a classical guide (CLA-a splint with a guiding cylinder) and a guide with an internal coolant channel (INT). They were fabricated from titanium powder by selective laser melting. Graduated drillings were performed using a pilot bur followed by two larger ones; infrared thermography was used to record the temperature of the drill upon exit and the peak temperature of the specimen right after the bur's retraction. RESULTS: The rise in bone temperature (mean ± standard deviation) while drilling through the CLA (INT) guide was 13.2 ± 3.6 (9.0 ± 3.4)°C for Drill 1, 4.3 ± 1.0 (2.1 ± 1.0)°C for Drill 2, and 2.1 ± 0.6 (0.4 ± 0.5)°C for Drill 3; the differences were statistically significant (p < 0.0032). To characterize individual differences between pairs of drillings conducted with different guides, Bland-Altman analysis was performed for the most thermogenic step. The mean difference between temperature elevations recorded with CLA and INT was -5.8°C, whereas the limits of agreement were 2.9°C and -14.4°C. In 95% of the cases, INT displayed more efficient cooling than CLA. CONCLUSION: Surgical guides with incorporated coolant channels ensure better heat removal than conventional guides. Further research is needed to assess bone overheating within a few hundred micrometers from the osteotomy edge.