# Heat Generated during Dental Implant Placement: A Scoping Review
## 2 Materials and Methods
### Cutter Wear  
Another important topic of discussion concerns the role of drill wear and the resulting loss of cutting capacity. Some researchers suggest that drill wear and reduced cutting efficiency result in a significant temperature increase during osteotomy (15; 83; 122).  
Some studies, such as that by [PERSON] et al. (123), have shown that even minimal use of a drill (n = 3) leads to a significant increase in temperature between osteotomies, which progressively increases with each new use of the drills.  
The study by [PERSON] et al. (124) compared three groups of drills: unused, used 600 times, and used for several months (i.e., more than 600 times, without giving an exact number). The findings indicated a significant difference between the three groups of drills, with some values exceeding the limit considered to be the wear limit threshold. The author recommended a frequent change of osteotomy drills, suggesting no more than 300 uses, and reported a small cost against important benefits.  
[PERSON] et al. (125) used each drill a total of 51 times, showing that with increased drill use came higher heat developed during the osteotomy phase. While no values exceeded the critical threshold, this study recommended a maximum of 40 uses per osteotomy drill. Electron microscope analyses also showed structural changes after autoclave cycles, which resulted in differences in the cutting capacity of the drill.  
The study by [PERSON] et al. (72), which used drills 35 times without sterilization, also aligned with previous findings, demonstrating increasing heat development with drill use up to 35 osteotomies, considered safe without sterilization between uses.  
The study by [PERSON] et al. demonstrated no significant difference after 30 implant bed preparations in terms of bone heating (80).  
Similarly, the studies by [PERSON] et al. (126) and [PERSON] et al. (127) all reported increased heat generation with drill wear and more osteotomies. [PERSON] et al. (128), for instance, used a drill for 25 osteotomies with no significant differences in heat generation. On the other hand, the study by [PERSON] et al. (129) found no significant differences in final temperatures, and thus in heat generation, after testing the drills for 50 osteotomies.  
[PERSON] et al. (43) and [PERSON] et al. (41) also found no significant temperature differences after 50 osteotomies. Both studies did not report temperature values above the critical value.  
The study by [PERSON] et al. showed no differences after 40 drill uses (130) and the study by [PERSON] et al. found no differences in terms of bone heating after 30 uses (131).  
The authors recommended adhering to the manufacturers' guidelines, which typically recommend drill replacement after 40 to 50 uses. Importantly, they also recommend considering factors like drill type, manufacturers, and materials.  
Further investigation is needed to establish a definitive threshold value for osteotomies beyond which drills should not be used. Many variables may affect this value, including drill type, shape, material, manufacturer, and autoclave cycles. In any case, 50 uses per drill should not be exceeded.  
In daily clinical practice, managing the number of uses of drills can be challenging, especially given that drill wear may vary depending on the type of bone previously prepared. Nonetheless, it is advisable to use new drills, particularly for type I bone preparations, in clinical practice.