Case series of laser-assisted treatment of excessive gingival display: an alternative treatment.

OBJECTIVE: The objective of this study was to investigate the stable and significant outcomes of laser-assisted lip repositioning technique for the treatment of excessive gingival display. BACKGROUND DATA: "Gummy smile" is a major concern for a large number of patients visiting the dentist. The hyperactivity of the upper lip is one of the main causes of a gummy smile, and several techniques have been proposed for its treatment. METHODS: Ten patients with excessive gingival display were treated with laser-assisted lip repositioning technique. The technique is composed of removing a strip of mucosa by laser incisions from the maxillary buccal vestibule, and coronal repositioning of the new mucosal margin. The clinical dimensions of gingival display were measured from the left, right posterior, and anterior sides at baseline, 6 and 12 months postoperatively. Subjects completed surveys to evaluate satisfaction with outcomes. Clinical and patient-centered parameters [visual analog scale for pain and aesthetics (VAS)] were measured at 7 days and again at 12 months after the surgery. RESULTS: The baseline anterior gingival display of 4.3±1.8 mm significantly decreased to 1.1±1.0 mm at 6 months (p<0.0001) and was maintained at 12 months (1.2±1.5 mm). The baseline left, right gingival display (4.9±2.2 mm; 5.0±1.4 mm) significantly decreased (1.2±1.4 mm; 1.3±1.1 mm) at 12 months (p<0.0001). Patients were satisfied with their smile after surgery and would likely choose to undergo the procedure again. CONCLUSIONS: The treatment of gummy smile with laser-assisted lip repositioning successfully reduced the preoperative gingival display without postoperative complications, in all cases.

Effect of enamel laser irradiation at different pulse settings on shear bond strength of orthodontic brackets.

OBJECTIVE: To compare the effect of laser irradiation at two different pulse settings and acid etching on the shear bond strength (SBS) of orthodontic brackets to enamel. MATERIALS AND METHODS: Thirty-six premolars were allocated to three groups (n  =  12): (1) 37% phosphoric acid etching, (2) erbium-doped yttrium aluminum garnet (Er:YAG) laser etching with medium-short pulse mode (MSP; 100 µs, 120 mj, 10 Hz, 1.2 W), and (3) Er:YAG laser etching with quantum-square pulse mode (QSP; 120 mj, 10 Hz, 1.2 W). Metallic brackets were bonded with Transbond XT. After photopolymerization, the samples were subjected to 5000 thermal cycles and debonded with a universal testing machine, and the SBS values were recorded. Surface morphology was evaluated with profilometric examination, scanning electron microscopy, and atomic force microscopy. The adhesive remnant index (ARI) was evaluated to assess the remaining adhesive. RESULTS: The results of SBS testing were analyzed by one-way analysis of variance and Tukey honestly significant diffference tests. The mean SBS values of QSP and MSP laser groups were 11.80 ± 2.7 MPa and 10.10 ± 4.5 MPa, respectively, and the QSP group demonstrated significantly higher SBS (P < .01) than that of the acid-etched group (6.6 ± 2.4 MPa). No significant difference was observed between the SBS values of the two laser groups (P < .05). The difference between the ARI scores of the laser groups and the acid-etched group was statistically significant (P < .05). CONCLUSION: Laser etching at MSP and QSP modes present successful alternatives to acid etching; however, long-term clinical studies are required to verify clinical success.