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Bone Healing After Piezosurgery and its Influence on Clinical Applications

2007; Elsevier BV; Volume: 65; Issue: 9 Linguagem: Inglês

10.1016/j.joms.2007.06.264

1531-5053

Stefan Stübinger,

Bone Tissue Engineering Materials

Osteotomies are well-established procedures in oral and maxillofacial surgery for either corrective measures or for gaining access to subjacent hard and soft tissues. Yet surgical reconstruction of bony defects can often be very challenging as thin and fragile bony structures are especially prone to fracture due to bulky cutting tips or massive application of pressure by conventional mechanical instruments. By employing the new technique of piezosurgery such complications can be overcome. It was the aim of this animal study to analyse the bone remodelling process after ultrasound osteotomy in the sheep tibia under functional loading after 8 and 12 weeks and to evaluate its impact on clinical applications. In 12 sheep the piezosurgery device (Mectron, Italy) was used to perform a midshaft osteotomy of the tibia diaphysis. The instrument operates with modulated ultrasound and thereby generates micromovements between 60 and 200 mm/sec. Physiological sodium chloride solution of approx. 4°C wasused as an irrigant. For all osteotomies bone saw OT7 with parameters mode boosted burst c and pump 5 were used according to the manufacturer's recommendation. All osteotomies were performed by one surgeon in a latero-lateral movement as well as in a turning guidance around the bone. After 2 and 3 months specimen were evaluated by radiographic and histologic analysis (toluidin-blue-staining, fuchsin-vital-staining). A complete, semi-quantitative and histomorphometrical evaluation was undertaken including fluorochromatic stainings indicative for bone remodeling. Data were compared to results gained by analogous experiments performed with other osteotomy techniques. Piezoelectric osteotomy permitted a micrometric, selective cut and a clear surgical site by the cavitation effect created by irrigation/cooling solution and oscillating tip. No excessive bleeding was encountered. The evaluation of the piezosurgery specimen proved 8 weeks as well as 12 weeks after surgery an ingrowth of vital bone-forming tissue into the osteotomy gap. The remodelling in the compact bone was undisturbed and the osteotomy gap was filled with new bone. Additional radiological findings supported these findings. The bone fragments were completely healed, the bone marrow cavity restored as well as the external callus formation was subsided undergoing piezoelectric surgery. In general bone healing was faster than known from conventional methods. Piezosurgery definitely enhances handling of delicate structures in the oral and maxillofacial region. Concerning osteotomies of thin and fragile bones, application of ultrasound is assessed to be superior to other mechanical instruments, because of easy handling, efficient bone ablation and minimal accidental harm to adjacent soft tissue structures. As bone healing is not disturbed by the piezosurgery, but even seems to be improved, this method will have a major influence on new minimally invasive bone surgery techniques with special regard to biomechanics.