CO2 laser oral soft tissue welding: An in vitro study

Objective: This study aimed to compare immediate tensile strength of the wound between suture and CO2 laser welding combined with suture in soft tissue blocks. Methods: The in vitro study was conducted in 40 samples of the blocks of 3 x 5 cm of ventral sides of pig tongues. The samples were randomly allocated into 2 groups; 20 samples each group. A 20 mm-length and 5 mm-depth incision was made in each sample. The samples of the control group were sutured with 3- stitch of 4-0 black silk. The samples of the experimental group were irradiated with CO2 laser at 800 Watt, 10 Hz, 0.2-ms pulse duration and 2,262.62 J/cm2 before sutured. The immediate tensile strength of the wound was measured by using customised tensiometer at the rate of 0.5 mm per minute. The wound dehiscence was observed under stereomicroscope. Results: The non parametric statistic was used due to non-normal distribution of data tested by Shapiro-Wilk test (P value = 0.525). The median of tensile strength of the control group and experimental group were 30.40 g/cm2 (the 25th percentiles = 16.8 g/cm2 and the 75th percentile = 74.6 g/cm2) and 40.50 g/cm2 (the 25th percentiles = 21.4 g/cm2 and the 75th percentile = 83.3 g/cm2), respectively. The difference was analysed using Mann-Whitney U test. There was no statistically significant difference of the immediate tensile strengths between the groups (P value = 0.577). The proportions of the samples without wound dehiscence at the 120 g/cm2 of tensile strength were 0.15 (3/20) in the control group and 0.35 (7/20) in the experimental group. Conclusion: The CO2 laser welding used in this study failed to show a greater immediate tensile strength but had a higher proportion of the wound without dehiscence at the 120 g/cm2 tensile strength by comparison with the suture.