A histologic evaluation of bone response to bur cutting with and without water coolant

Thirty-six bony cuts were made in the lateral aspect of the mandibles of mongrel dogs. Irrigation was employed in eighteen cuts, while the remaining eighteen were cut without irrigation. Histologic specimens were obtained at 1 hour, 1 day, 3 days, 1 week, and 3 weeks. Early specimens showed marked clot retraction from the bony walls in the nonirrigated cuts, while irrigated cuts demonstrated more firmly adherent and better organized clots. In later specimens, bone formation was less mature in the defects made without irrigation. Inflammation and necrosis of bone were minimal or absent in all sections. Defects made without irrigation exhibited delayed healing in this study.