Healing of osteotomy sites applying either piezosurgery or two conventional saw blades: a pilot study in rabbits

Abstract

Purpose: The purpose of this study was to compare bone healing of experimental osteotomies applying either piezosurgery or two different oscillating saw blades in a rabbit model.

Methods: The 16 rabbits were randomly assigned into four groups to comply with observation periods of one, two, three and five weeks. In all animals, four osteotomy lines were performed on the left and right nasal bone using a conventional saw blade, a novel saw blade and piezosurgery.

Results: All three osteotomy techniques revealed an advanced gap healing starting after one week. The most pronounced new bone formation took place between two and three weeks, whereby piezoelectric surgery revealed a tendency to faster bone formation and remodelling. Yet, there were no significant differences between the three modalities.

Conclusions: The use of a novel as well as the piezoelectric bone-cutting instrument revealed advanced bone healing with a favourable surgical performance compared to a traditional saw.

Fig. 1

Novel saw blade (200.054; CMT SA, Chemical Milling Technology, La Chaux-de-fonds, Switzerland) during osteotomy of the nasal bone. After careful preparation and elevation of skin and underlying soft tissue structures, the saw blade could be directly applied onto the bone surface. Reduced need of manual pressure and vibration allowed a safe guidance and performance of the cutting procedure

Fig. 2

Intra-operative situation after soft tissue preparation and accomplished osteotomies lines. Two pairs of parallel osteotomies of 20 mm performed by the novel (right side) and a conventional saw blade (left side). The osteotomy pairs are 5 mm apart from each other in the long axis of the nasal bone. Note the fine osteotomy line of the novel saw blade. The parallel osteotomy lines on each side were connected by a perpendicular osteotomy across applying piezosurgery. To guarantee a safe loosening and interconnection of osteotomies, the osteotomies were slightly overdesigned

Fig. 3

Percentages of analysed tissue components within the osteotomy gaps during the observation period from one to five weeks. In each table the development and amount of tissue structures are summarised with standard deviations (whiskers) after applying conventional saw, novel saw, or piezosurgery. Individual values of each technique are summarised in Table 1. a Vascular structures (VS). b Provisional matrix (PCT). c Osteoid. d Mineralised bone (MB). Piezosurgery; Saw 1 = novel saw blade (CMT); Saw 2 = conventional saw blade (Synthes®)

Fig. 4

Summary of histological results. Specimens after 1 week (a, b, c) were stained with haematoxyline-eosine to clearly identify soft tissue structures and matrix in the early healing phase. Specimens after 2 weeks (d, e, f), 3 weeks (g, h, i) and 5 weeks (j, k, l) were stained with Toluidine blue to evaluate new bone formation and bone remodelling. The left column represents piezosurgery (a, d, g, j), the middle column the novel saw blade (b, e, h, k) and the right column the conventional saw blade (c, f, i, l). All three osteotomy techniques disclosed a characteristic gap healing with bridging of the osteotomy site with immature and woven bone in the initial healing stage. After five weeks all techniques revealed an advanced remodelling with lamellar structures

Fig. 5

Five-week gap healing after piezosurgery. The osteotomy gap is almost completely filled with mature mineralised bone undergoing remodelling. Toluidine blue, 40×