Effect of pulse duration on wound healing using a CO2 laser

The authors investigated wound healing of incisions in the buccal mucosa of a canine model created using a CO2 laser with a short pulse structure (60 mu s, 100 mu s, and 120 mu s) rather than a conventional continuous wave structure in a shuttered mode. The tissue from 10 animals was evaluated histologically and with tensiometry acutely and at postoperative days 3, 7, and 14. A Bonferroni-Dunn corrected ANOVA analysis at a 95% significance level was used to compare the effect of pulse duration on histologic morphology and wound tensile strength. The data indicate that shorter laser pulse durations create less lateral thermal injury (P < .009) and wounds with greater tensile strength (P < .005), resulting in earlier wound healing. The results also show that heat, sufficient to damage tissue, was conducted to adjacent tissue during laser pulses of 100 ys and longer. These results demonstrate that surgical CO2 lasers with a short pulse structure of approximately 60 mu s or less could offer more prompt wound healing while maintaining the advantages of a 10.6-mu m wavelength laser.