Comparative evaluation of thermal impact of 980nm diode laser on soft tissue using irrigation and non-irrigation...

Diode laser is one of the most captivating technologies in dental practice. In periodontics, when used at appropriate settings, it possesses the best properties for selective surgical and nonsurgical procedures such as subgingival calculus removal without a thermal change of the root surface, and also provides tissue surface sterilization. However, lasers always produce a certain amount of thermal damage to the soft tissues. Therefore, this study aimed to comparatively evaluate the thermal impact of 980-nm diode laser incisions, when used with irrigation versus nonirrigation systems.

The study was conducted on 24 gingival tissue samples obtained from the goat's mandible and maxilla. The samples were divided into two groups of 12 samples each, and laser incisions were given in 4 power settings, using 980-nm diode laser in super short pulse mode, with and without saline irrigation. Martius Scarlet Blue staining technique was used to prepare the histological slides. Then, slides were examined under a research microscope (Olympus CX 21), and the pictures of the slides were taken by mounting the camera onto the microscope mobile mount. The microscopic images hence obtained were analyzed for the depth and width of the incisions, area of carbonization, necrosis, and reversible damage, using the Digimizer image analysis software.

The results of this study demonstrated that the mean incision depth was higher (592.49 ± 180.97, P < 0.05), with less carbonization (25.52 ± 29.21, P = 0.00) and less necrosis (311.63 ± 156.441, P < 0.05) in the laser incisions with irrigation, as compared to the laser incisions given without irrigation system.

Within the limitations of this study, it can be concluded that using an irrigation system causes less collateral damage while maintaining the incising efficiency of the diode laser. Further studies with a higher sample size, controlled irrigation systems, and incision techniques are needed to evaluate the efficiency of diode lasers for the clinical explanation of the results.