Can We Determine an Appropriate Timing to Avoid Thermal Pulp Hazard During Gingivectomy Procedure? An In Vitro Study with Diode Laser.

Objective: Diode laser (DL) is a frequently preferred tool for soft tissue incision and ablation in oral surgery. The aim of this study was to find the most effective irradiation time protocol to avoid potential harmful temperature rise in pulp during DL-assisted gingivectomy. Materials and methods: Ninety human freshly extracted teeth (30 anterior, 30 premolar, and 30 molar) were irradiated using a 940 nm DL with power output of 1 and 2 W and exposure time of 10, 20, 30, 40, 50, and 60 sec per specimen. Intrapulpal temperature was evaluated with thermocouple. Additionally, the effect of dark deposits on root surface for intrapulpal temperature rise was investigated. Temperature differences with every 10 sec were evaluated for three different teeth types, and statistical analyses were performed. Results: Anterior and premolar teeth exceeded the threshold values earlier than molar teeth for both 1 and 2 W. Despite the significant differences among the types of teeth, at 10 sec, temperature rise recorded for all types of teeth was below the critical value of 5.6°C, which cause pulp damage. Dark deposits on teeth surface boosted thermal effect of DLs (p < 0.01). Conclusions: Gingivectomy with DLs at 1 W on anterior, premolar, and molar teeth for 20, 40, and 60 sec, respectively, generates acceptable temperature rise; however, it should be <10, 20, and 40 sec at 2 W, respectively. Especially in the anterior teeth, DLs should be performed with caution to avoid pulp damage.