Heat generation during implant placement: effect of bone density,implant design and surgical technique

Research goal The purpose of this study was to investigate the effects of bone density, implant design, and implant insertion speed on the heat generated during implant insertion. Material and method Three thermal couples (Advance Instrument Inc., Taiwan) was placed in 1mm,5mm,9mm depth respectively, and the temperature change was measured during implant placement. <Artificial test block> Low to high density cancellous bone without cortical coverage were simulated with 10 pounds per cubic foot (pcf) (density: 0.16 g/cc), 20 pcf (0.32 g/cc) polyurethane foam test blocks. Cancellous bone with a thin layer of cortical bone were simulated with laminated test blocks using a combination of 0 or 1 mm 50 pcf (density: 0.80 g/cc) polyurethane layer. Inserting two different implants were NobelActive™ implant (Nobel Biocare, Sweden) with 10mm in length and 4.3mm in diameter and Branemark System™ MKIV TiUnite implant (Nobel Biocare,Sweden) with 10mm in length and 4mm in diameter。 Three paralleled channels for thermal couples were drilled around the implant site. The channels were 0.5mm away from the planned implant site. The bone block was socked in a water bath (Almore International Inc., USA) which was maintained in 29±2℃.Then, implant was placed by motor (NSK, Japan) and the temperature change was recorded during the implant placement by16 channel thermal meter (VTI Instruments Corp, U.S.A). Result: In MKIV groups, there were no statistically difference on temperature change when different insertion speeds were used. However, with increasing bone block density, the temperature change were increased. The maximum temperature was increased in 1+10pcf bone block, it show that the laminated layer has significantly influence on the friction heat. Moreover, No matter what the bone density and insertion speed were used, the temperature change in 5mm depth were more than in 1mm depth and 9mm depth. In NA groups, It was also that no statistically difference between the different insertion speed. With the different bone density on 10pcf and 20pcf , It is statistically difference on temperature change on 1mm,5mm,9mm. Moreover, when 20pcf bone block compared with 1+10pcf bone block, it is statistically increased on temperature change in 1mm depth. When comparing NA with MKIV in 20pcf bone block, the MKIV groups had more friction heat generation on 1mm,5mm and 9mm depth , and it is statistically difference. It mean that implant design had influence on the temperature change Conclusion: In the present study, the factors that had influence on temperature change during implant insertion were the bone density and implant design. It is no statistically difference with different implant insertion speed.