## 2 Materials and Methods
### Thermodynamic Measurements  
Figure 2 illustrates the experimental setup used for thermodynamic measurements [26]. The 3D-printed surgical guide was mounted on the bone model (1) and secured with locking pins (one of them is visible on the bottom part of the inset). This assembly was then placed horizontally and locked on the workbench using a vise (2). A Strong ACL(B)-42I (Saeshin, Daegu, Republic of Korea) handpiece (3) was attached to the rotating end of a 1.2 m-long wooden arm (4). To achieve a constant 2 kg-force axial load, as suggested by [PERSON] et al. [15], we adjusted the position of a sliding weight (5) while measuring the force using a hanging scale (precision of 1 g). We recorded the temperature simultaneously near the 4 consecutive osteotomy sites with K-type thermocouples connected to a factory-calibrated Digi-Sense 20250-50 digital thermometer (Cole-Parmer Instrument Company LLC, Vernon Hills, IL, USA) (6). The thermocouple tips, coated in thermally conductive paste, were positioned at the bottom of predrilled holes inside the artificial bone models. These holes were oriented perpendicularly to the osteotomy and located 0.8 mm away from the edge of the largest-diameter drill. After inserting the thermocouples, we sealed the holes using Vaseline to keep the irrigation fluid away from the thermocouples. During drilling, the osteotomy sites were irrigated with distilled water at room temperature (25 \({}^{\circ}\)C), delivered by a Saeshin X-Cube (Saeshin, South Korea) physiodispenser at a rate of 40 mL/min.  
When using the classical surgical guide, the coolant pipe was attached to the nozzle of the handpiece. In contrast, with the guide featuring an internally routed irrigation channel, the coolant pipe was connected directly to the incorporated tube (7).  
Figure 2: Schematic representation of the thermodynamic measurement setup: (1) surgical guide fixed on the bone model, (2) worktable-fixing mount, (3) handpiece, (4) rotating arm, (5) adjustable weight, (6) digital thermometer with thermocouples, and (7) cooling pipe connected to the incorporated irrigation channel of the surgical guide. The inset is a picture of the surgical template wrapping the bone model during a drilling sequence performed with the guides with internal cooling. Note the irrigation tubing connected to the incorporated coolant pipe; the tubing connected to the physiodispenser was only used when drilling was performed with the classical guides.  
The bone models were kept in a thermostatic distilled water bath at 25 \({}^{\circ}\)C for at least one hour before measurements. The specimens and the type of surgical guides being evaluated were chosen randomly at the beginning of each experiment. The drilling speed was set at 1500 rpm at a torque of 50 N-cm [15]. We consecutively used three drills (2.7 \(\times\) 8 mm, 4 \(\times\) 8 mm, and 4/4.3 \(\times\) 8 mm) from the Easydent Regular/Wide Kit (Neodent, Curitiba, Parana, Brazil); their diameters were 2.7 mm, 3.3 mm, and 3.7 mm, respectively. We recorded the corresponding temperature curves at all four osteotomy sites. After measurements, the artificial bone specimens were placed back into the water bath to dissipate the heat generated while drilling.