Combination of Q-switched ND:YAG and fractional erbium:YAG lasers in treatment of melasma: a randomized controlled clinical trial

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

[Comparison of shear bond strength of orthodontic attachments bonded to sandblasted amalgam with different adhesives]

Bonding orthodontic attachments to large amalgam restorations of posterior teeth is a challenge. The aim of this study was to evaluate and compare the shear bond strength [SBS] of orthodontic attachments bonded to amalgam with different chemical surface preparations. In this in vitro study 105 convex amalgam surface samples were subjected to aluminium oxide sandblasting. The amalgam sampless were randomly divided into three equal groups. In each group buccal tubes were bonded with Transbond Plus using Reliance Metal Primer [RMP], All Bond II [AB2], and Alloy Primer [AP]. Thirty-five human teeth served as the controls to test buccal tube bonding to acid-etched enamel with Transbond Plus and Transbond XT. All the samples were stored in artificial saliva; after thermocycling for 1000 times, all the sampels were tested for SBS. Data were analysed with Kruskal-Wallis and Mann-Whitney tests. There were statistically significant differences in SBS values between all the groups [p value < 0.001]. AB2 created the strongest bond to amalgam [6.75 MPa]. However, there were no significant differences between SBS values achieved with AB2 and those in the control group [p value = 0.455]. No Significant differences were observed between AP and RMP [p value = 0.051] but both had significant differences with the control group [p value < 0.001]. The results of the present study revealed that AB2 intermediate resin is useful for strong bonding of metal orthodontic attachments to dental amalgam