Erb:YAG and Hol:YAG Laser Osteotomy: The Effect of Laser Ablation on Bone Healing

Abstract

Sixty-nine male Sprague Dawley rats were divided into three groups of 23 animals each and osteotomies were performed in group 1 with a power saw, in group 2 with the Erb:Yag laser, and in group 3 with the Hol:YAG laser. Two animals of each group were sacrificed 1 week, 4, 8, and 12 weeks after operation for histologic investigation, and five animals of each group at 4, 8, and 12 weeks after osteotomy for torque testing. Anterior-posterior (AP) radiographs were taken at the same time points and investigated for callus formation and development of pseudoarthrosis. All tibiae osteotomied with the Hol:YAG laser (group 3) developed pseudoarthrosis within 12 weeks and, therefore, torque testing could not be performed for this group. Biomechanical measurements of bone treated by power saw or Erb:YAG laser osteotomies, respectively, showed no significant statistical difference in the stability of bone between the two groups. Histologic examination after 1 week exhibited fibrous tissue at the site of osteotomy in rats of all three groups and additionally carbonization in rats of group 3. Saw osteotomies resulted in more callus formation than Erb:YAG osteotomies, but both techniques provoked a certain reunion within 8 weeks. Hol:YAG laser-treated osteotomies, however, exhibited formation of dense fibrous tissue, carbonization and no callus formation within 12 weeks. Radiographic pictures showed more callus formation for saw osteotomies as compared to those performed with the Erb:YAG laser. For Hol:YAG laser osteotomies pseudoarthrosis was identified also radiologically.

Advances in bone surgery: the Er:YAG laser in oral surgery and implant dentistry

“…Charlton et al 94 could demonstrate that the erbium laser caused a zone of secondary damage to surrounding tissue of about 5 µm, whereas this zone was greatly increased to 80 µm with significant charring in the case of holmium. Similar results were presented by Buchelt et al 95 In a histological and biomechanical (torque testing) study in rat tibiae, the authors compared bone healing after the use of an Er:YAG and Ho:YAG lasers with a power saw. Although Ho:YAG laser-treated osteotomies exhibited formation of dense fibrous tissue, carbonization, and no callus formation within 12 weeks, Er:YAG and saw osteotomies provoked a certain reunion within 8 weeks.…”

Ultrastructural analysis of bone tissue irradiated by Er:YAG Laser

“…In dentistry, Er:YAG laser has been suggested for various purposes [10][11][12][13][14]22]. Especially, in periodontal therapy, this laser may be used for hard and soft tissue treatments such as gingivectomy, periodontal pocket curettage, root surface debridement, and osseous recontouring and removal of diseased soft tissue during periodontal surgery.…”

Femtosecond Laser Effects on Osseous Tissues

“…In living specimen, we have demonstrated that no thermal damage occurs on cells immediately adjacent to the wounded area as seen by evidence of active cell surface enzymes. These results w^ould suggest that bone healing may not be impaired in femtosecond laser surgery as is the case with nanosecond lasers [3]. These results will need to be validated in vivo.…”