Laser Soldering with a Biosolder for Oral Mucosa Wound Closure in an Experiment

The aim of the study was to evaluate the efficiency of wound closure of soft tissues using a 970 nm diode laser and a biosolder based on bovine serum albumin and single-wall carbon nanotubes in experimentally modelled oral cavity defects.

The experimental study was carried out on 16 chinchilla rabbits. Linear defects of the oral mucosa 1 cm long were modeled. The animals were divided into 2 groups, 8 rabbits in each group. The wounds in the control group animals were sutured with a surgical suture using Prolene 5-0 thread; the experimental group animals were sutured using laser soldering and a biosolder based on bovine serum albumin, indocyanine green, single-wall carbon nanotubes, and type I collagen, followed by putting additional sutures using Prolene 5-0 thread. We used the proprietary laser device with a wavelength of 970 nm with adaptive thermal stabilization of the suture, which enabled to set the heating temperature of the biotissue in the laser suture area with an accuracy of ~1°C preventing thermal necrosis of tissues.The biological tissues of 24 samples of the rabbit oral mucosa were fixed on days 1, 3, 5, and 10 and examined morphologically and morphometrically.

Inflammatory changes were primarily associated with a response to the suture material; proliferative changes (neoangiogenesis and epithelial regeneration) were related to the proliferation activation of fibroblasts and epithelial cells due to the laser exposure. The use of a biosolder contributed to additional tissue adhesion, which further on accelerated the regeneration process and increased the neoangiogenesis rate and the vascular density per 1 mm².In the experimental group, the inflammatory reaction was completed by day 5, while in the control group, the residual inflammatory signs persisted in some samples up to day 10. On day 10, the proliferative phase began in the experimental group. An immunohistochemical analysis revealed a statistically significant increase in the number of blood vessels in the experimental group by 70.6% compared to the control (p=0.003).

The use of laser exposure combined with a biosolder promoted tissue adhesion improvement, shortened the inflammatory phase, and accelerated the regeneration providing minimal scarring. The data obtained emphasize the prospects of using the suggested technique for oral mucous wound closure in clinical practice for patients with various dental diseases.