Histologic evaluation of alveolar bone following CO2 laser removal of connective tissue from periodontal defects.

This study was undertaken to examine histologically the healing response of alveolar bone following removal of granulation and/or connective tissues from interproximal craters by manual curettage or ablation by carbon dioxide laser. The time required to complete each type of degranulation procedure was also compared. Four interproximal treatment sites in each quadrant of two dogs were randomly assigned to each treatment modality. Neither treatment modality was totally effective in removing all suprabony connective tissue. Healing was clinically uneventful and histologically similar for both treatment groups at all time intervals. Laser-treated specimens exhibited little or no inflammatory cell infiltrate, areas of heat-induced tissue necrosis, accumulations of carbonized debris that initially was surrounded by macrophages and eventually phagocytized by multi-nucleated giant cells, and spicules of nonvital bone that exhibited a surface layer of osteoid. Although manual curettage was found to be statistically significantly faster, the difference between mean times was roughly 55 seconds and therefore unlikely to be clinically significant.