Unraveling the Stability Dip: How to Eliminate Bone Trauma
Overheating compromises the regenerative capacity of bone and its mechanical properties. High insertion torque causes more bone resorption and delayed bone healing.
Implant Failure Causes
Dr. Alves began by discussing the various causes of implant failure, noting that it can result from patient-related factors, implant design issues, or surgical techniques. This presentation focused on"over-compression of the bone and overheating"as key factors affecting bone healing and implant success.
Importance of Bone Healing and Stability
He emphasized the importance of "primary stability" to avoid fibro-integration and implant loss. Stability is influenced by bone quality,implant design, length, diameter, and surgical technique. The formation of necrotic bone around the implant osteotomy is a critical issue,influenced by the extent of bone trauma.
Understanding Thermal Damage
Thermal damage to bone cells starts at 50°C, with alkaline phosphatase denaturing at 56°C. Dr. Alves highlighted the "critical threshold for bone necrosis at 47°C for 1 minute." Overheating can lead to severe consequences like hyperemia, protein degeneration, osteocyte death, osteoclasis, and bone necrosis. He presented clinical cases linking bone necrosis to implant placement, particularly in denser bone (D1 bone),where symptoms of implant failure due to overheating include pain, inflammation, fistulas, radiolucent areas, and implant mobility.Dr. Alves reviewed research on bone heating,noting that many studies are in vitro or animal based with varying quality and biases. He listed factors affecting overheating, including bone density, cortical thickness, drill diameter, material,wear, pressure, and speed. He recommended"intermittent drilling with a pumping motion" for better cooling and debris removal, though there is no consensus on the best irrigation technique,and the temperature of the saline is also important.
Considering Drill Designs and Techniques
Drill design also impacts temperature increase,with conical drills and certain fluted drills potentially being more efficient. Studies suggest that drills should be used within a range of 30-50 uses to remain effective. Dr. Alves warned that“bone compression over a certain threshold can cause deformation, fractures, ischemia, and necrosis."
Comparing High Torque vs. Low Torque
He compared high torque and low torque during implant placement, explaining that high torque can cause bone cracks and necrosis, whereas lower torque allows better bone formation.Studies show "good survival rates for implants placed with low insertion torque," indicating that high insertion torques are not a guarantee for successful osseointegration. Dr. Alves advised clinicians to "avoid overstressing the bone during implant surgery" and suggested that future implant systems should focus on optimized drill protocols and macro designs to derive stability from trabecular bone rather than merely compressing the cortical layer.In conclusion, Dr. Alves reiterated that overheating and high insertion torque compromise bone regenerative capacity and mechanical properties. He stressed that"mechanical stability should consider bone quality and intended loading protocol."The clinical implications of his lecture highlight the importance of maintaining bone health during implant procedures, using careful surgical techniques, and appropriate drilling protocols to avoid thermal and compressive bone trauma,emphasizing lower insertion torque for better long-term implant success. By focusing on these points, clinicians can enhance their practices to achieve better implant outcomes and reduce the risk of bone trauma and implant failure.