# Heat Generated during Dental Implant Placement: A Scoping Review
## 2 Materials and Methods
### Preparation Tools  
The critical temperature of 47 degrees during implant site preparation can lead to bone healing failure due to osteonecrosis. This challenge has motivated the development of different preparation protocols, including techniques such as piezoelectric and laser surgery, which minimize the applied force and friction generated at the implant site. Piezoelectric instruments work on bone with a vibration frequency ranging between 24 and 32 kHz. A key advantage of using these tools lies in their minimally invasive and safe nature: accidental contact with soft tissue does not result in damage because their vibration frequencies are selective for mineralized tissue [68].  
Studies have shown that the piezoelectric approach to implant bed preparation yields results comparable to those of traditional preparation methods in terms of implant survival rates [69; 70].  
[PERSON] et al. [71] investigated the maximum temperature reached by bone preparation with piezoelectric instruments for cycles of 6 and 4 s, consistently finding variations in temperature rise, though temperatures always remained below the critical threshold of 47 degrees. Temperature variations are influenced by factors including the force applied during bone preparation, movement management, and type of bone [72].  
Conversely, [PERSON] et al. [73] observed a significant temperature increase with the use of piezoelectric systems compared to conventional milling drills, attributing this difference to the longer working time of these tools.  
Similar results were found by [PERSON] et al. [74] and [PERSON] et al. [75], where a piezoelectric system showed higher temperatures than conventional drilling, especially at the apical portion.  
To reduce the risk of bone overheating, this technique requires precise irrigation [76] and a light pressure load, coupled with a quarter-turn rotary movement, to enable enhanced bone cutting efficacy and the dissipation of potential energy.  
[PERSON] et al. found a medium pressure as the most favorable in terms of bone heating [77].  
As for laser ablation, i.e., Erbium:yttrium-aluminium-garnet (Er:YAG), lasers work on bone with a wavelength of 2940 nm, causing evaporation of interstitial water upon irradiation. This technique has numerous advantages, including the absence of vibration and friction, a bactericidal effect, reduced tissue bleeding and injuries to adjacent tissue, and precise geometric cuts with regular edges. This method, which has a depth propagation of around 30 microns, is considered to have no influence on the bone healing process [78].  
Using infrared thermography, [PERSON] et al. investigated [79] the overheating of bone produced by piezoelectric surgery, Er:YAG lasers in contact and non-contact modes, piezoelectric instruments, and conventional surgical drills on rat tibia. The highest temperatures measured never exceeded 40 degrees. Their findings revealed that both Er:YAG and piezoelectric surgery are safe alternative methods to conventional surgical drills in dentistry.  
Similar results were obtained in [PERSON] et al.'s study and [PERSON] et al.'s study, where they demonstrated no difference between twisted drills and piezoelectric instruments in terms of bone heating [19; 80].