Thermal, mechanical, and densification analysis of osteotomy drill designs for implant placement: an analysis on foam blocks representing type IV bone.

Objectives: To analyze the effects of three osteotomy drill designs (conventional [CON], reverse helix [REX], and densification [DEN]) and running directions on heat generation, primary implant stability (PS), block-to-implant contact (BIC)%, peri-implant block volume (BV), and resistance to unscrewing forces in a low-density alveolar bone model.

Method and materials: Eighty-eight dental implants were inserted into artificial bone blocks using manual and computer-controlled osteotomies. Temperature changes (Δ°C), insertion torque value (ITV), resonance frequency analyses (ISQ), BIC%, and BV were measured. Statistical analyses used ANOVA and Kruskal-Wallis tests (p<0.05).

Results: DEN drilling produced the lowest Δ°C (17.52±2.57°C and 28.06±4.35°C for 2nd and 3rd drills), while CON had the highest (27.53±5.17°C and 38.03±8.08°C). Counter-clockwise (CCW) CON drilling significantly reduced Δ°C compared to clockwise (CW). DEN achieved highest PS (38.01±1.87 N/cm, 65±4.69 ISQ) and removal torque (25.4±5.08 N/cm), while CON CW had lowest (33.23±2.91 N/cm, 61.83±4.28 ISQ). DEN showed the highest BV (87.71±4.23 mm³) but the lowest BIC (49.12%±2.93%). CCW CON drilling improved ITV over CW (36.21±3.63 vs 33.23±2.91 N/cm).

Conclusion: DEN drilling demonstrated superior performance in heat reduction, PS, and BV, but had lower BIC%. CCW running of CON drills showed improvements over CW in several parameters. While DEN excelled in most aspects, its lower BIC% and the positive outcomes of CCW CON drilling warrant further investigation.