## 4 Discussion  
This study confirmed the hypothesis that including an irrigation fluid channel in the design of a surgical template brings about a significant reduction in the temperature rise caused by dental implant bed preparation. To minimize the errors associated with differences between bone specimens, the study was conducted on artificial bone models whose architecture and material properties were similar to those of the human mandible. Also, to recapitulate a common clinical practice (the osteectomies involved in the All-on-4 dental implant insertion protocol), we performed sequential drillings at four target sites on each bone model with each type of surgical guide. The surgical template was designed to wrap the artificial bone specimen while leaving sufficient space between its bottom and the target surface to allow for the evacuation of the irrigation fluid (see Supplementary Materials, Video S1). It included four subunits (regions), each of them comprising a common cylindrical sleeve guide and a guide outfitted with an internal coolant pipe. In sequential osteotomy, the bone does not return to the initial temperature between consecutive drillings, being on an upward heating slope. This is of no concern, however, because experimental [27] as well as computational [28] studies indicate that the maximum temperature reached in sequential drilling is much lower than the peak temperature attained in a single drilling of the same final diameter. Furthermore, the thermally affected layer resulting from predrilling is removed by the next drill, so the osseointegration of the implant depends on the temperature elevation caused by the final drilling. In this respect, computational models of the temperature field offer valuable insights since the most affected zone is next to the osteotomy margin, which escapes measurements [5,28]. Although it seems reasonable to assume that internal cooling is effective, the results reported in the literature are mixed. For example, [PERSON] et al. monitored the intraosseous temperature during osteectomies performed on bovine ribs under four conditions [23]: (C1) combined external and internal irrigation in the presence of a surgical guide with an internal coolant tube, (C2) external irrigation in the presence of a classical surgical guide, (C3) no irrigation in the presence of a classical surgical guide, and (C4) free-hand surgery with external irrigation. Temperatures were recorded by K-type thermocouples at 1.5 mm from the edge of the final osteotomy at depths of 1.5 mm, 7 mm, and 12 mm from the bone crest. The largest temperature increments were observed in the cortical bone layer (at  
Figure 7: Bland–Altman plots illustrating the discrepancies in temperature increases (\(\Delta\)T) during osteectomies with the two surgical guide designs: the one with internal coolant channel (INT) and the classical one (CLA). Each panel corresponds to data acquired with a different drill type: (**A**) the pilot drill, (**B**) the second drill, and (**C**) the final drill. Circular markers represent differences between temperature elevations recorded while using INT and those obtained while using CLA in the same region of the artificial bone specimen. The mean value of differences (Mean) is the bias, marked by a dashed blue line, while the limits of agreement are depicted by dashed red lines. The blue and red shaded bands represent the 95% confidence intervals of the bias and the limits of agreement, respectively. 1.5 mm depth); the medians of temperature elevations were 3.0 \({}^{\circ}\)C for C1, 2.3 \({}^{\circ}\)C for C2, 3.2 \({}^{\circ}\)C for C3, and 2.0 \({}^{\circ}\)C for C4, with no significant differences between them.