ABSTRACT
Surgical implant procedures and insertions can result in mechanical and thermal damage to the involved bone. When dental implants are inserted, thermal injury can exponentially increase with augmented temperatures that may be caused by friction between fixture and drilled bone. Excessive heat induces delayed regeneration due to bone cell necrosis and implant mobility, resulting in dislocation of the hydroxyapatite structure. These are considered to be key factors in early failure of implant therapy. The current in vitro experimental study measures heat that is generated by implant placement in adjacent mandibular bovine bone. Research is conducted in two stages: first, using in vitro tests and second, with Abaqus software computer simulations. Bovine ramus is used as osseous model. We place a thermocouple ~ 2 mm from the rim of an osteotomy during seating of each dental implant. Finite-elements analysis models assess seven BioHorizons Laser-Lok implants with different diameters. We find that average temperatures increase from 0.2°C to 7.8°C. With heat indeed generated, a low-temperature rise is produced by implant surface friction against freshly cut bone surface. Although bone is a poor thermal conductor, implant titanium and the steel shank of the handpiece bur are better at heat conduction. Larger diameter and implant displacement may act as a heat sink to draw away generated heat that is caused by friction of seating the implant at the bone-implant interface. During in vitro experiments and simulated modeling, we find that none of the implants, regardless of diameter/length, reach an eccentric temperature range necessary for bone necrosis.
