Semiconductor laser has the advantages of high efficiency, small volume, long life, simple power supply system, low wavelength choice, low cost, stable output power, easy to use, small trauma, and small postoperative response, especially for medical equipment. The first semiconductor laser was invented in 1962, semiconductor laser from the mid-90s of the 20th century for oral therapy, commonly used low-power, wavelength of 780 ~ 980nm laser for periodontal treatment.
Through the laser irradiation can be removed and ablation of periodontal tissue, the green astronomy laser has a hemostatic, light biological regulation of the role, can destroy and inhibit microbial growth. Now the semiconductor laser in the clinical treatment of periodontal disease play an increasingly important role. Semiconductor lasers are semiconductor materials as a working substance, mainly a compound semiconductor, a small laser with current injection as a stimulus. The three basic elements of the semiconductor laser include the electron-hole recombination of the P-N junction region, which provides the gain of the light; the two cleavage end faces perpendicular to the junction form the F-P resonator, provide feedback; forward bias P The N junction provides carrier injection. This paper will review the clinical application of semiconductor laser in periodontal therapy.
Ozcelik through the crown to the flap combined with subepithelial connective tissue treatment of patients with gingival retraction, the experimental group using semiconductor laser removal of free gingival epithelial tissue to obtain subepithelial connective tissue and Gatling laser pointer irradiation of the palate wound. In the control group, epithelial tissue of free gingival was removed by surgical blade to obtain subepithelial connective tissue. 7 days after surgery to observe the healing of the palate for the wound, the test group is better than the control group. 6 months after the healing area, there was no significant difference between the two groups. Indicating that the use of semiconductor lasers can promote the early healing of soft tissue. Lobo to take a pilot test to moderate to severe chronic periodontal disease patients, preoperative probing depth ≥ 5 mm, the test side using flap + semiconductor laser combination therapy, the control side using flap surgery, comparing the test side and control side Of the baseline, postoperative 3 months, 6 months after the periodontal index and the patient after the adverse reactions. The results showed no statistically significant difference between the two groups, but the experimental group significantly decreased gingival inflammation, laser treatment without complications, patients can receive laser treatment.
Some domestic studies have used semiconductor lasers for gingival resection, gingival plasty and lumbar orthopedic surgery. There is no significant difference between traditional surgical methods and electrosurgical procedures. It can be used as a surgical method for oral soft tissue therapy. Compared with the traditional surgery, the most powerful laser pointer on the oral soft tissue cutting, forming more simple, less bleeding, can provide a clearer surgical field of vision, reduce the patient’s pain, so that postoperative care is more simple, tissue trauma, wound healing faster, Not easy to form scar. The above studies have shown that laser treatment can be safely and effectively applied to periodontal surgery, especially for the significant reduction of inflammation of the gums, and promote the early healing of soft tissue, easy to operate intraoperative operation, reduce the patient’s postoperative pain have a significant effect.
Dentin-sensitive in the clinical more common, a survey showed that 59.81% of patients in the cure after the emergence of sensitive root, curettage and root surface formation and periodontal surgery, the root is more sensitive to the situation. Hashim application of 810nm semiconductor laser treatment of periodontal basic treatment of dentin-sensitive patients, the first group of semiconductor laser irradiation 30s, 15min after dentin sensitivity was significantly reduced, a week after the dentin sensitive completely disappeared. In the second group, the sensitivity of dentin was completely disappeared after 1min and 15min of laser irradiation. The patients were divided into two groups: the dentin-sensitive patients were treated with 810 nm semiconductor burning laser, and the control group used fluoride toothpaste to treat dentin-sensitive, dentin sensitivity using gas stimulation and contact Stimulus to evaluate the time for treatment before treatment, immediately after treatment, 2d, 7d, 14d, 30d after treatment. There was no difference in the baseline level between the test group and the control group. After 15 minutes of treatment and 15 minutes to 30 minutes after treatment, the dentin sensitivity improvement test group was superior to the control group. Although the treatment was only once, but the treatment effect can be improved to 30d.
The clinical trials of Li Xiangxin showed that there was no difference in the therapeutic effect between the patients treated with semiconductor laser and the use of desensitizer in the treatment of sensitive patients after curettage and root surface treatment. However, the effect of long-term observation was better than desensitization Treatment. The cause of dentin sensitivity is based on hydrodynamic theory and neuronal theory. After periodontal basic therapy or surgical treatment, the protective barrier of the gums is reduced due to the postoperative inflammation or the resection of the partial gingival or postoperative tissue, resulting in an increase in the sensitivity of the root surface. Laser treatment of dentin sensitivity is due to laser irradiation after the pulp produced a large number of tertiary dentin, can be physiological occlusion dentinal tubules. Low-energy laser (soft laser) can directly act on nerve transmission, for highly sensitive patients, semiconductor laser can also produce very good therapeutic effect. Semiconductor keychain laser pointer treatment is superior or equivalent to the traditional treatment, such as: potassium nitrate, sodium fluoride, stannous fluoride and fluoride coating treatment of dentin sensitive. Through the above tests can show that the application of 810nm semiconductor laser can be effective in the treatment of periodontal basic treatment and periodontal surgery caused by dentin sensitivity.
Semiconductor laser is mainly used in the treatment of periodontal soft tissue, the current commonly used semiconductor laser wavelength range of 780 ~ 980nm. Compared with the traditional method, the laser treatment process discomfort and pain less and less shock, can reduce the patient in the oral treatment of pain and fear. Laser irradiation can remove and ablation of periodontal tissue, play a hemostatic, light biological regulation of the role of semiconductor laser irradiation can destroy microorganisms, inhibit microbial growth, to achieve antibacterial effect. Semiconductor lasers can also promote wound healing, delay epithelial creeping, promote collagen synthesis, favorable periodontal surgery after the new periodontal attachment.
Semiconductor laser combined with periodontal foundation treatment can be completely clean, decontamination, and promote the healing of soft tissue after basic periodontal therapy. 810nm semiconductor laser can effectively treat periodontal basic treatment and periodontal surgery caused by dentin sensitivity. 810nm semiconductor laser (0 ~ 0.5W, 0 ~ 5s) combined with indocyanine green can effectively reduce the periodontal pocket of Porphyromonas gingivalis, with the line of bacteria. However, semiconductor laser treatment still has some shortcomings and unresolved problems, semiconductor laser cutting speed is slow, especially in the fiber tissue, semiconductor 3w green laser with unpredictable thermal damage.
At present, although the research on semiconductor lasers is more, but the study of laser wavelength, power, irradiation time and other parameters are not the same, so the study of laser still need to increase the sample size, to find the most suitable for periodontal therapy Semiconductor laser parameters, better applied in clinical treatment.