Journal of Lasers in Medical Sciences

Introduction: Ablative and nonablative lasers have been used to treat melasma. We aimed to assess and compare the combining Q-switched Nd:YAG laser (QSNYL) and fractional erbium:YAG laser (FEYL) with QSNYL alone in treatment of melasma.

Methods: This randomized controlled clinical trial was performed in our Research Center during 2013-2014. Women with melasma and without a history of keloid formation, hypersensitivity to hydroquinone, or pigmentary changes due to laser therapy were randomly allocated to receive four sessions of either QSNYL-FEYL combination or QSNYL alone. All patients received topical treatment with Kligman’s formula. Before laser therapy and 4 weeks after the last treatment session, patients’ skin was assessed for changes in skin color, melanin content, and erythema intensity of melasma lesions quantitatively.

Results: Finally, 21 patients in QSNYL-FEYL and 20 in QSNYL group (mean age, 38.57 [5.60] and 42.60 [8.44] years, respectively) completed study. The skin color had become lighter in both groups (mean [SD] percentage change of 56.95 [40.29] and 29.25 [13.20] in QSNYL-FEYL and QSNYL groups, respectively) with significantly better results in QSNYL-FEYL group (P = 0.006). Percentage of decrease of melanin content was significantly higher in QSNYL-FEYL group (22.01 [10.67] vs. 7.69 [4.75]; P < 0.001). After adjustment for baseline values, the post treatment intensity of erythema was significantly lower in QSNYL-FEYL group (P < 0.001). The patients reported no adverse events.

Conclusion: QSNYL-FEYL was significantly more effective in decreasing melanin content of lesions than QSNYL and led to a lighter skin.

Introduction: Pemphigus vulgaris (PV) is a chronic, serious autoimmune mucocutaneous bullous disease. Oral lesions in PV may be extremely painful. This pain may adversely affect the patients’ oral intake and quality of life. This before-after clinical trial was designed to assess the pain relieving effects of single session of non-ablative, non-thermal CO2 laser therapy (NTCLT) in oral lesions of PV.

Methods: Fifty painful oral lesions of fourteen patients with PV were illuminated by CO2 laser (power: 1 W, scanning the lesions with rapid circular motion of the handpiece) passing through a thick layer of transparent gel with high water content. The pain severity of the oral lesions was reported by the patients up to the fourth postoperative day. They were also asked to continue their existing systemic treatment during the course of this study as a precondition for the participation.

Results: The severity of contact and non-stimulate (non-contact) pain declined immediately and significantly after NTCLT (P < 0.001). The pain relieving effect was sustained during the four successive days of follow-up. The procedure was pain free and no kind of analgesics was required. Following NTCLT, there were no visible thermal complications such as destruction, ablation or irritation of the oral lesions.

Conclusion: The results of the trial proposed that single session of NTCLT could immediately and significantly relieve pain in oral lesions of PV, without any visible thermal complications.

Introduction: To compare endovenous laser ablation (EVLA) and radiofrequency ablation (RFA) in different legs in the same individual in patients with venous insufficiency.

Methods: Sixty patients with bilateral saphenous vein insufficiency were included. EVLA or RFA was applied to one of the patient’s legs and RFA or EVLA to the other leg.

Results: EVLA and RFA complications were hyperemia at 20.7% and 31.0%, ecchymosis at 31.0% and 51.7% and edema at 27.6% and 65.5%, respectively. The rate of recanalization was 6.8% in the RFA group. No recanalization was observed in EVLA group. The level of patients satisfied with EVLA was 51.7%, compared to 31.0% for RFA, while 17.2% of patients were satisfied with both procedures. Times to return to daily activity were 0.9 days in the EVLA group and 1.3 days in the RFA group.

Conclusion: EVLA procedure may be superior to RFA in certain respects.

Introduction: This study was performed to determine the shear bond strength of rebonded mechanically retentive ceramic brackets after recycling with Erbium-Doped Yttrium Aluminum Garnet (Er:YAG) laser or sandblasting.

Methods: Twenty-eight debonded ceramic brackets plus 14 intact new ceramic brackets were used in this study. Debonded brackets were randomly divided into 2 groups of 14. One group was treated by Er:YAG laser and the other with sandblasting. All the specimens were randomly bonded to 42 intact human upper premolars. The shear bond strength of all specimens was determined with a universal testing machine at a crosshead speed of 0.5 mm/min until bond failure occurred. The recycled bracket base surfaces were observed under a scanning electron microscope (SEM). Analysis of variance (ANOVA) and Tukey tests were used to compare the shear bond strength of the 3 groups. Fisher exact test was used to evaluate the differences in adhesive remnant index (ARI) scores.

Results: The highest bond strength belonged to brackets recycled by Sandblasting (16.83 MPa). There was no significant difference between the shear bond strength of laser and control groups. SEM photographs showed differences in 2 recycling methods. The laser recycled bracket appeared to have as well-cleaned base as the new bracket. Although the sandblasted bracket photographs showed no remnant adhesives, remarkable micro-roughening of the base of the bracket was apparent.

Introduction: Three-dimensional (3D) scanners are widely used in medicine. One of the applications of 3D scanners is the acquisition of anthropometric dimensions for ergonomics and the creation of an anthropometry data bank. The aim of this study was to evaluate the precision and accuracy of a modified 3D scanner fabricated in this study.

Methods: In this work, a 3D scan of the human body was obtained using DAVID Laser Scanner software and its calibration background, a linear low-power laser, and one advanced webcam. After the 3D scans were imported to the Geomagic software, 10 anthropometric dimensions of 10 subjects were obtained. The measurements of the 3D scanner were compared to the measurements of the same dimensions by a direct anthropometric method. The precision and accuracy of the measurements of the 3D scanner were then evaluated. The obtained data were analyzed using an independent sample t test with the SPSS software.

Results: The minimum and maximum measurement differences from three consecutive scans by the 3D scanner were 0.03 mm and 18 mm, respectively. The differences between the measurements by the direct anthropometry method and the 3D scanner were not statistically significant. Therefore, the accuracy of the 3D scanner is acceptable.

Conclusion: Future studies will need to focus on the improvement of the scanning speed and the quality of the scanned image.

Introduction: The aim of this study was to evaluate the effect of various concentrations of NaOCl on shear bond strength of composite resin to dentin of primary teeth, prepared with laser and bur.

Methods: In this in vitro study, 48 primary molars were sectioned at mesiodistal direction and were randomly divided into 6 groups; G1: bur, G2: bur + NaOCl 2.5%, G3: bur + NaOCl 5.25%, G4: laser, G5: laser + NaOCl 2.5%, G6: laser + NaOCl 5.25%. One-Step Plus adhesive was applied after phosphoric acid gel and NaOCl over the dentin surfaces for all groups, and composite resin cylinders were bonded to the samples. After thermocycling, shear bond strengths of composite resin to dentin were measured and statistical analyses were done by means of t test and analysis of variance (ANOVA).

Results: The mean shear bond strength showed no significant difference between the groups prepared with bur (13.82 ± 3.49) and laser (14.18 ± 3.65) (P > 0.05). The mean difference of shear bond strength between three groups G1, G2 and G3 and between G4, G5 and G6 were not statistically significant (P > 0.05). Scanning electron microscopy (SEM) figures showed an irregular surface in laser groups and fairly complete removal of smear layer from the orifices of the dentinal tubules, in the group in which NaOCl was used.

Conclusion: The application of different concentrations of NaOCl does not significantly improve the bond strength in dentin surfaces prepared with laser or bur.

Introduction: The purpose of the present study was to evaluate the different concentrations of sodium hypochlorite activated with laser in removing of the smear layer in the apical, middle, and coronal segments of root canal walls by scanning electron microscopy analysis.

Methods: Sixty single-rooted human mandibular teeth were decoronated to a standardized length. The samples were prepared by using Race rotary system to size 40, 0.04 taper and divided into 4 equal groups (n = 15). Group 1, irrigated with EDTA 17% and 5.25% NaOCl, groups 2, 3 and 4, 1%, 2.5%, and 5% NaOCl activated with Nd:YAG laser, respectively. Teeth were split longitudinally and subjected to scanning electron microscope (SEM). Data were analyzed by Kruskal-Wallis, Mann-Whitney tests. P value of <0.05 was considered statistically significant.

Results: Five percent NaOCl LAI (laser-activated irrigation) showed best smear layer removal in test groups and the difference was statistically significant (P < 0.001). Control group (EDTA 17% and 5.25% NaOCl irrigation) showed significantly better outcomes in comparative with test groups (P < 0.001). In the apical third, compared to coronal and middle third, the canal walls were often contaminated by inorganic debris and smear layer.

Conclusion: All different concentrations of sodium hypochlorite activated with laser have a positive effect on removing of smear layer. Sodium hypochlorite activated with laser removed smear layer more effectively at the coronal and middle third compared to the apical third.

Introduction: The aim of this study was to assess the effect of low-level laser therapy (LLLT) on pain, swelling and maximum mouth opening in patients undergoing third molar surgery.

Methods: A prospective, randomized double-blind study was undertaken on 44 patients at the Dental School, Ahvaz Jundishapur University of Medical Sciences, in 2015. A low-level laser was randomly applied on one of the two sides after surgery of 15 patients. The experimental side received 18 J/cm2 of energy density, wavelength of 980 nm, and output power of 1.8 W. On the control side, a hand-piece was applied intra-orally, but laser was not activated. In addition, in order to evaluate trismus, 13 patients were treated by unilateral laser therapy and 16 patients did not receive laser therapy at all. The laser was administered intraorally on two points of vestibular and lingual sides at 1 cm from the surgery site, and extraorally at the emergence of the masseter muscle, immediately after surgery, and repeated 24 hours later. The pain, swelling and maximum mouth opening (MMO) were compared between the two groups at 24 hours and a week after surgery.

Results: The mean score of pain 24 hours after surgery in the laser therapy group (2.3 ± 3.5) was significantly lower than the mean score of pain in the drug therapy (4.19 ± 3.09) (P = 0.036). Moreover, the mean score of pain at one week after surgery in the laser therapy group (0.13 ± 2.33) was significantly lower than the drug therapy group (1.43 ± 2.45) (P = 0.046). The amount of swelling according to different measurements did not significantly differ between the two groups neither at 24 hours nor at 1 week after surgery.

Conclusion: Our findings showed that LLLT was useful in reducing pain and could slightly reduce swelling compared to drug therapy in impacted third molar surgery.

Introduction: The treatment of cutaneous leishmaniasis (CL) is based primarily on the use of pentavalent antimonials, which may lead to many side effects limiting their use. Photodynamic therapy (PDT) is an alternative for the treatment of CL, and some xanthene dyes have the potential for use in PDT.

Methods: The xanthenes rose bengal B (RB) and its derivatives rose bengal methyl ester (RBMET), and butyl ester (RBBUT) were analyzed for leishmanicidal activity against promastigotes and intracellular amastigotes of Leishmania amazonensis. Cytotoxicity was assessed in J774.A1 macrophages.

Results: RB derivates RBMET (IC50 9.83 μM), and RBBUT (IC50 45.08 μM) showed leishmanicidal activity, however, were toxic to J774.A1 macrophages, resulting in low selectivity index.

Conclusion: The RBMET and RBBUT showed to be effective against the L. amazonensis and the low selectivity index presented may not be a limitation for their use in PDT to CL treatment.

Introduction: Periodontitis is an inflammatory periodontal disease that leads to tooth loss. Recently laser has been introduced as an alternative treatment for periodontitis. The aim of the present study was to compare the effect of Erbium-doped Yttrium Aluminum Garnet (Er:YAG) laser with ultrasonic scaler in patients with moderate chronic periodontitis.

Methods: In this randomized single-blind clinical trial, 27 patients with moderate chronic periodontitis were selected. One quadrant of the patients was treated by Er:YAG laser and the other one by ultrasonic scaler. Clinical parameters, including periodontal pocket depth (PPD), papillary bleeding index (PBI) and clinical attachment level (CAL) were measured before, as well as 6 and 12 weeks after treatment. Data were analyzed by SPSS 20 software using Friedman test, paired t test, independent t test and Mann-Whitney test. The significance level was set at 0.05.

Results: The means of clinical parameters in both groups were significantly improved in the first and second follow-ups (P < 0.001). Although the means of PPD, PBI and CAL were slightly higher in the laser group than in the ultrasonic group, the differences were not statistically significant between these two groups (P > 0.05).

Conclusion: Although both ultrasonic scaler and Er:YAG laser could effectively improve clinical periodontal parameters, the results did not reveal the superiority of Er:YAG laser over ultrasonic scaler or vice versa.