Histomorphometric evaluation of bone grafts harvested by different methods.

AIM

Many studies proposing the use of autologous bone to correct bony defects of the oral district have been published, and numerous protocols have been proposed to simplify the harvesting of particulate bone. However, no qualitative evaluation of the harvested bone has been reported. The study provides a qualitative evaluation of autologous bone harvested by 9 methods: the harvested bone was analysed through microphotography and histomorphometric analysis, measuring the surface area of bone fragments and the percentages of vital and necrotic bone.

METHODS

Nine harvesting methods were employed: round bur on low-speed hand-piece (40000 rpm), bur on high-speed hand-piece, spiral implant bur on low-speed hand-piece (1000 rpm), safe scraper, Rhodes' back-action chisel, rongeur pliers, gouge shaped bone chisel, mectron piezosurgery. Ten bone harvests were taken from the retromolar bone using the 9 methods, during extraction of embedded wisdom teeth (indication to extraction was for orthodontic reasons). The histocytological preparations were analysed with microphotography and histomorphometric analysis, evaluating particle size, percentage of vital bone and number of osteocytes per unit of surface area.

RESULTS

Histomorphometric analysis showed that non-vital bone accounted for 100% of harvested bone, with a complete absence of osteocytes, in specimens harvested with burs and safe scraper. Percentage of non-vital bone was intermediate, with a low number of cells, in specimens harvested with back-action, gouge shaped bone chisel, spiral bur and piezosurgery. The best results were achieved with rongeur pliers and by en bloc harvesting.

CONCLUSIONS

The results show that the best methods to harvest vital bone are: gouge shaped bone chisel, back-action, en bloc harvesting, rongeur pliers and piezosurgery, although the latter method leaves some empty gaps in the tissue. The bone harvested with round bur on low-speed hand-piece, bur on high-speed hand-piece, spiral implant bur, or safe scraper are not suitable for grafting as indicated by the absence of osteocytes and the predominance of non-vital bone.