Low-intensity Laser Therapy in the Treatment of Gingival Recession

The purpose of this study was to evaluate the 6-month outcomes of applying low-intensity laser therapy associated with connective tissue grafts to treat gingival recession.

This was a prospective, parallel and controlled clinical trial. The population evaluated in this study was selected at ICT - São José dos Campos, College of Dentistry.

The selected patients were randomly allocated (by a computer generated list) into:

Group CTG (n = 20) - patients who received connective tissue graft to treat gingival recession Group CTG+LILT (n = 20) - patients who received connective tissue graft associated with 8 applications of low-intensity laser therapy to treat gingival recession.

The surgeries, as well as all postoperative follow-up, were performed at the dental clinic of ICT- UNESP. Surgical areas were anesthetized (2% mepivacaine with 1:100,000 epinephrine). Two horizontal incisions were made at right angles to the adjacent interdental papillae, at the level of the CEJ, without interfering with the gingival margins of neighboring teeth. Two oblique vertical incisions were extended beyond the mucogingival junction, and a trapezoidal mucoperiosteal flap was raised up to the mucogingival junction. After this point, a split-thickness flap was extended apically, releasing the tension and favoring coronal positioning of the flap. The exposed root surface was gently scaled and planed to remove any possible irregularities. Afterward, a thin and small connective tissue graft was harvested from the palate using a scalpel with parallel blades (1.0 mm away from each other). The graft was sutured# using single sutures in the papillae, over the root surface, in such a way that covered the CEJ and the recession. Then, the flap was coronally positioned and sutured to completely cover the graft The patients allocated for the test group received the following protocol for laser application: Five (5) points of irradiation were performed, as depicted in Figure 1. The irradiation was performed with a GaAlAs\*\* diode laser that continuously emitted a wavelength of 660 nm. 30 mW was used for 20 seconds, and the total applied energy density (fluence) was 15 J/cm2 (3 J/cm2 per point and an application time of 4 seconds per point)

Clinical parameters were assessed at baseline and 3 and 6 months post-operatively.

Statistical Analysis The null hypothesis considered in the study was the absence of difference in the clinical parameters between the different groups. For data analysis, the statistical program was used (Sigmaplot). The demographic and clinical data were compared between the groups using Student's t-test. The data were first analyzed for homogeneity using the Shapiro-Wilk test, which indicated non-normal distribution. . Those presenting Shapiro-Wilk p values \< 0.05 were analyzed using a Friedman test (for intragroup comparisons) and Mann-Whitney tests (for intergroup comparisons). Patients' esthetics and discomfort measures using VAS were analyzed by T-tests. The frequency of sites that were scored as very good or excellent in each group by QCE analysis, the frequency of complete root coverage, BOP, and the presence or absence of plaque at the site were compared using χ2 tests. Intergroup RES comparisons were performed with a T-test. A significance level of 0.05 was adopted.

Eligibility Criteria:
Inclusion Criteria:

1. presenting Miller class I or II gingival recession in the maxillary canines or premolars;
2. visible cemento-enamel junction (CEJ) in the teeth included in the study and pulp vitality;
3. patients presenting no signs of active periodontal disease and full-mouth plaque and bleeding score ≤ 20%;
4. patients older than 18 years old;
5. probing depth ˂ 3 mm in the included teeth; 6) patients who agreed to participate and signed an informed consent form

Exclusion Criteria:

1. patients with systemic problems (cardiovascular, blood dyscrasias, immunodeficiency, and diabetes, among others) that will contraindicate the surgical procedure
2. patients taking medications known to interfere with the wound healing process or that contraindicate the surgical procedure
3. smokers or pregnant women
4. patients who underwent periodontal surgery in the area of interest; and 5) patients with orthodontic therapy in progress.