A Comparative Study of Mucosal Wound Healing after Excision with a Scalpel, Diode Laser, or CO2 Laser

Abstract

We aimed to compare the clinical and histological secondary healing effectiveness of various types of high-level laser versus scalpel excision in mucosa frenectomy.

Methods: Forty-five Sprague Dawley rats were used in this study. These rats were divided into two laser intervention groups (CO₂, n = 15; diode, n = 15) and one control group with scalpel excision (n = 15). The effectiveness of therapy has been assessed based on the comparison of intraoperative, postoperative, and histological parameters on days 7, 21, and 35, and postoperative weight changes as pain indicator.

Results: Both laser groups demonstrated significantly (P < 0.05) less bleeding than did the control group during the intraoperative stage, whereas the CO₂ laser showed more precise cutting compared with the diode laser (P < 0.05). The highest healing score was reported in the CO₂ and scalpel groups on the first week of healing than in the diode group (P < 0.05). However, no significant difference was observed between the groups on days 21 and 35. Weight loss was significantly (P < 0.05) demonstrated in the diode group compared to the scalpel and CO₂ groups till day 7. Both laser groups demonstrated delayed healing process compared with the scalpel. Nevertheless, the CO₂ group followed the scalpel trends after day 7.

Conclusion: Scalpel and CO₂ laser yielded a superior clinical outcome compared with the diode excision of oral mucosa, whereby the CO₂ has been proposed as the most effective laser type at the end of the first postoperative month.

Fig. 1.

Weight change in Sprague Dawley rats. The delta differences of Sprague Dawley rat body weights changed 3 days postoperative when compared with those at the starting point, with correlation to days after the frenectomy procedure, depending on the tool with which they were operated on. **P value less than 0.01.

Fig. 2.

Hematoxylin & eosin sections of the lingual frenulum after frenectomy day 7. Histological photomicrographs of the scalpel, CO₂, and diode groups at day 7 of the healing period. The first row demonstrates a 40× magnification of the incision site; the second row is a 100× magnification of the site. Two-sided black arrows indicate epithelization. Blue arrow heads represent vascularization; orange arrow heads, inflammatory cells; black arrow heads, fibroblast; and yellow arrow heads, collagen bundles.

Fig. 3.

Microscopic evaluation scores: evaluations of histological wound healing. A, Score of inflammation. B, Score of vascularization. C, Score of epithelization. ECM evaluation index (D) of hematoxylin and eosin and Masson trichoma staining depends on the tool used at each point of time. Gray indicates scalpel; blue, CO₂; and red, diode. *P < 0.05, **P < 0.01.

Fig. 4.

Picrosirius red staining under polarized light. Collagen organization under polarized light microscopy in full color presentation, RGBs (A, D, G). Red spectrum of light represents collagen I (B, E, H), and green spectrum of color represents collagen III (C, F, I). Groups: scalpel (A–C), CO₂ (D–F), and diode (G–I). Original magnification: 100×.

Fig. 5.

Collagen ratio type I/III count at 1 week, 3 weeks, and 5 weeks postoperative. The score of evaluation index for hematoxylin and eosin staining depends on the tool used. Gray indicates scalpel; blue, CO₂; red, diode. *P < 0.05, **P < 0.01.