Adapted preparation technique for screw-type implants: explorative in vitro pilot study in a porcine bone model

Current dental implant procedures rely on achieving sufficient primary stability through bone condensation. While insertion torque is a key indicator of this stability, the relationship between drilling diameter and torque remains underexplored. Prior research has shown that bone mineral density (BMD) influences implant stability, but how drilling parameters can be adjusted to optimize outcomes in variable bone quality is unclear. This gap motivated an investigation into how controlled drilling diameters affect insertion torque in cancellous bone. No prior work had resolved how bone condensation can be systematically manipulated to enhance stability. The need for a drilling technique that adapts to bone quality is evident, especially in patients with poor bone mineralization. This study aimed to address this by quantifying the effect of drilling diameter on insertion torque. The findings could help refine surgical protocols to improve implant success rates in challenging bone conditions.

This study aimed to evaluate how varying drilling diameters affect the insertion torque of self-tapping implants in cancellous bone. The specific problem addressed was the lack of a standardized method to adjust drilling based on bone quality. The motivation came from the need to improve primary stability in patients with low bone mineral density. By correlating drilling diameter with insertion torque, the researchers sought to develop a more reliable technique for implant placement. The study focused on cancellous bone, which is known for its lower density and reduced stability. The goal was to determine if a bone-dependent drilling approach could enhance torque values in poor-quality bone. The use of a porcine bone model allowed for controlled testing of implant insertion under varying conditions. This approach could lead to better clinical outcomes by optimizing implant stability through tailored drilling techniques.

The study used cancellous porcine vertebral bone to simulate implant placement in low-density bone. Four drill diameters—2.85 mm, 3 mm, 3.15 mm, and 3.35 mm—were tested to assess their effect on insertion torque. Bone mineral density (BMD) was measured using dental quantitative computed tomography before implant insertion. Brånemark system Mk III implants (3.75 x 11.5 mm) were placed in 141 sites after drilling. Insertion torque was recorded during implantation. The correlation between drilling diameter and torque was analyzed across different BMD values. The study design allowed for a direct comparison of torque values across varying drilling diameters. The use of a standardized implant model ensured consistency in measurements. The experimental setup enabled precise control over drilling parameters and implant insertion conditions.

The study found that reducing the drill diameter from 3 mm to 2.85 mm increased insertion torque by approximately 17%. Increasing the diameter to 3.15 mm or 3.35 mm led to decreases in torque by 21% and 50%, respectively. These results indicate a strong correlation between drilling diameter and insertion torque. Bone mineral density (BMD) values ranged from 330 to 500 mg/cm³ across the tested sites. The highest torque values were achieved with the smallest drill diameter. The results suggest that tighter drilling improves bone condensation, thereby enhancing primary stability. The study demonstrated that torque values can be optimized in low-BMD bone using an individualized drilling approach. The findings support the use of bone-dependent drilling techniques to improve implant stability in poor-quality bone.

The authors concluded that insertion torque is significantly influenced by the diameter of the implant bed. Smaller drill diameters increase torque values, while larger diameters reduce them. This relationship was consistent across varying bone mineral density (BMD) values. The study supports the use of a bone-dependent drilling technique to optimize implant stability. The results suggest that individualized drilling can enhance primary stability in low-BMD bone. The findings indicate that controlled bone condensation improves torque, which is essential for immediate function. The study did not propose new drug targets or future research directions. Instead, it emphasized the potential clinical benefit of adapting drilling techniques to bone quality. The authors suggest that this approach could improve outcomes in patients with poor bone mineralization.