The Effect of Undersized Drilling on the Coronal Surface Roughness of Microthreaded Implants: An In Vitro Study

Abstract

This in-vitro study assessed the effect of an underdrilling implant placement protocol on the insertion torque, implant surface temperature and surface roughness (Sa) topography of the cervical microthreads of implants. Three groups of 25 implants (3.75 mm × 10 mm) were placed in osteotomies prepared in an artificial bone disc with final diameters of 3.65 mm according to the manufacturer’s instructions and in osteotomies prepared in accordance with an underdrilling protocol with final drill diameters of 3.2 and 2.8 mm (groups D3.65, D3.2, D2.8, respectively). Implants were inserted at a constant rate of 30 rpm. The surface temperature of the implants was measured with a thermal camera and temperature amplitude (Temp-Amp) was calculated by subtracting the room temperature from the measured implant surface temperature. Upon implant retrieval, coronal surface topography was assessed using a Nanofocus µsurf explorer and compared to a set of 25 new implants (control group). The differences between groups were compared using one-way ANOVA (p < 0.05). Significantly higher insertion torque, surface temperature values and significantly smaller average Sa values were measured in the implants inserted in undersized preparations. The highest temperature, insertion torque and Temp-Amp values and the largest decrease in Sa were measured in the D2.8 group. The lowest values were measured in the D3.65 group.

Statistical Process Control Charts Applied to Rock Disintegration Quality Improvement

“…The strain gauge head (ten-so-metric head) is articulated to the piston rods (8) of the hydraulic cylinders (9). The handle of the sliding ram (10) is firmly attached to stand (12). The flushing water is drained through a high-pressure hose (12) (see Figure 3).…”

“…The drilling tool's performance and its efficiency depend on many structural elements, such as the construction of the tool body, the geometry of the cutting part, the flushing system of the device, and the setting of the optimal working mode. One of the possible measurable output parameters of the drilling process is the vibration signal of the acceleration [8][9][10][11][12].…”