Space-making effect for new bone formation by suppressing scar contraction of mucosal epithelium of rat tooth extraction wound using diode laser and CO2 laser treatment

Yusuke Taniguchi; Etsuko Matsuzaki; Yuki Daigo; Takashi Tsutsumi; Hiroshi Fukuoka; Kae Kakura; Kei Egashira; Kazuya Takahashi; Hirofumi Kido

doi:10.1016/j.jds.2021.11.004

Space-making effect for new bone formation by suppressing scar contraction of mucosal epithelium of rat tooth extraction wound using diode laser and CO₂ laser treatment

J Dent Sci. 2022 Apr;17(2):1001-1008. doi: 10.1016/j.jds.2021.11.004. Epub 2021 Nov 26.

Authors

Yusuke Taniguchi¹, Etsuko Matsuzaki^{2

3}, Yuki Daigo⁴, Takashi Tsutsumi^{3

5}, Hiroshi Fukuoka⁶, Kae Kakura¹, Kei Egashira¹, Kazuya Takahashi⁴, Hirofumi Kido¹

Affiliations

¹ Section of Oral Implantology, Department of Oral Rehabilitation, Fukuoka Dental College, Fukuoka, Japan.
² Section of Operative Dentistry and Endodontology, Department of Odontology, Fukuoka Dental College, Fukuoka, Japan.
³ Oral Medicine Research Center, Fukuoka Dental College, Fukuoka, Japan.
⁴ Department of Geriatric Dentistry, Osaka Dental University, Osaka, Japan.
⁵ The Center for Visiting Dental Service, Department of General Dentistry, Fukuoka Dental College, Fukuoka, Japan.
⁶ Fukuoka Dental Office, Kagoshima, Japan.

Abstract

Background/purpose: As an extraction wound closes, the mucosal epithelium of the tooth extraction wound impedes the space for new bone formation by invading into the extraction socket. Thus, the height of the alveolar crest decreases, causing significant depression of the alveolar mucosa. In this study, we created a rat tooth extraction model and examined the effects of laser irradiation by CO₂ and diode on the dynamics of myofibroblast expression through α-SMA, and TGF-β1.

Materials and methods: After tooth extraction of five-week-old male Wistar rats, they were divided into two laser treatment groups (CO₂ laser or diode laser was irradiated into tooth extraction socket) and non-laser treatment group (control group). Surrounding tissues, including the extraction socket, were removed at 3, 5, 7, and 21 days after tooth extraction and the expression of α-SMA and TGF-β1 was verified using immunohistological techniques (6 animals in each group and each period, 72 animals in total).

Results: α-SMA-positive cells and TGF-β1-positive areas were significantly lower in the two laser treatment groups than in the control group. Particularly, the diode group almost had no TGF-β1-positive areas on the 21st day when healing after tooth extraction was deemed to be completed.

Conclusion: Both CO₂ and diode laser irradiation of tooth extraction wounds decreases α-SMA-positive cells and TGF-β1-positive areas. Further, it causes a decrease in myofibroblast expression and suppresses the invasion of mucosal epithelium into the extraction socket. Therefore, laser irradiation may exert a space-making effect for new bone formation and also contribute to socket preservation.

Keywords: CO2 laser; Diode laser; FDA, the US Food and Drug Administration; HILT, high-intensity laser therapy; Mucosal epithelium; PBMT, photobiomodulation therapy; Socket preservation; TGF-β1; α-SMA.