INTRODUCTION: The superior properties of diode lasers such as sterilization, coagulation and ease of use has made revolutionary improvement in treatment aspects in dentistry. The light energy emitted by the laser is absorbed by tissues which gets converted to heat and may cause undesirable tissue damages in the periodontium. A threshold temperature increase of 7oC is considered as the highest biologically acceptable temperature increase to avoid periodontal damage. Thus, this questions the utility of laser in the wide array of surgical periodontal therapy such as excision, grafting and regenerative procedures.
MATERIALS AND METHODS: In this study, the temperature variations while using 810 nm diode laser for cutting and biostimulation of soft tissues in operculectomy and gingivectomy procedures were investigated with an infrared thermometer. Temperature was recorded before, during and after the procedure in a thermally controlled environment.
RESULTS: There was an increase in temperature at the site of diode laser application when used for cutting with an average increase of 4oC. On histological examination of the biopsied specimens where laser incision was performed, signs of thermal damage such as hyperpigmentation, hyalinization and vacuolization were assessed. Biostimulated tissue did not show any signs of thermal damage on histological analysis.
CONCLUSION: In accordance with the results of the study, although there was a temperature increase and thermal injury to the tissues, laser irradiation did not induce a temperature change high enough to cause irreversible damage to the soft tissues. The histological observations such as coagulation of capillaries and hyalinization could be an indication that laser may not be ideal for harvesting grafts as it causes disruption of the vascularity. Laser also distorts histology, mimics dysplasia and hence interferes with diagnosis of the pathologist during biopsy.
