Effects of coaxial CO2/Nd:YAG irradiation on periodontal wound healing

This study evaluated a coaxial CO2/Nd:YAG laser used during periodontal surgery in mongrel dogs for the purpose of ablating the osseous portions of root surfaces to increase reattachment of soft tissue. Periodontal defects were produced with ligatures of orthodontic wire and elastics. The left mandibular osseous root surfaces were irradiated with a defocused, CW laser beam [power density (PD) = 42.46 W/cm2, energy density (ED) = 424.63 J/cm2]. The left maxillary osseous root surfaces were treated with a beam at twice the energy density [PD = 84.93 W/cm2, ED = 849.3 J/cm2]. The mandibular right quadrant received conventional surgery and the maxillary right quadrant served as the untreated control. Fourteen days after treatment, facial/lingual attached gingivae were scored for soft tissue adherence to bone. Laser irradiation at low ED did not improve soft tissue attachment when compared to conventional treatment. Higher ED irradiation produced significantly less attachment and increased tissue necrosis.