AIM:Considering the recent introduction of universal adhesives and the controversy regarding the use/no use of etchant prior to their application, this study sought to assess the microtensile bond strength of composite to enamel using universal adhesive with/without acid etching compared to three-step etch and rinse, two-step etch and rinse and two-step self-etch bonding agents.METHODS:This in vitro, an experimental study was conducted on 80 extracted sound human molars in five groups (16 each): Scotchbond Universal adhesive (3M) with/without prior etching, Adper Scthe otchbond Multi-Purpose, Single Bond and Clearfil SE Bond. Etching was performed with 37% phosphoric acid for 20 seconds followed by rinsing and drying. The bonding agent was then applied and light-cured. The e-lite composite was bonded to surfaces and light-cured. The teeth were then mounted, sectioned and subjected to microtensile bond strength test in a universal testing machine. The mode of failure was, determined under a stereomicroscope. Data were analysed using one-way ANOVA followed by Tukey’s test.RESULTS:Universal adhesive with prior etching yielded the highest bond strength (P = 0.03). Pairwise comparisons showed that the bond strength of this group was significantly higher than that of universal adhesive without prior etching (P = 0.04). No other significant differences were noted (P > 0.05). The modes of failure were significantly different among the groups (P = 0.003).CONCLUSION:Enamel etching with phosphoric acid can significantly increase the bond strength to universal adhesive. Universal adhesive without prior etching provided the bond strength as high as that provided by etching and rinse and self-etch bonding agents.

Introduction: Bracket bonding to porcelain has high failure rate compared to bonding to enamel. Aim: This study aimed to assess the shear bond strength (SBS) of metal brackets to porcelain using a universal adhesive. Material and Methods: In this in vitro experimental study, 40 porcelain blocks (1x1x1 cm 3 )were divided into four groups (n=10). The porcelain surfaces were etched with 10% hydrofluoric (HF) acid and bonded to metal brackets using Transbond XT composite and the following bonding protocols: Transbond XT bonding agent alone in group 1, silane plus Transbond XT bonding agent in group 2, silane plus universal adhesive (G-Premio bond) in group 3 and universal adhesive alone in group 4. The SBS was measured using a universal testing machine at a crosshead speed of 1 mm/minute. Fracture surfaces were evaluated under a stereo microscope, and the adhesive remnant index (ARI) scores were determined. Results: The highest and the lowest SBS values were noted in groups 3 (17.06±2.58 MPa) and 4 (9.85±4.76 MPa), respectively. Type of adhesive had no significant effect on SBS (P=0.611). However, the effect of application of silane on SBS was significant (P=0.000). Groups subjected to the application of silane showed higher SBS values than others. The mode of failure was mainly adhesive in groups 2 and 3, and adhesive and mixed in groups 1 and 4. The difference in ARI scores was statistically significant (P=0.016). Conclusion: Universal adhesive and Transbond XT were not significantly different in SBS. However, application of silane significantly increased the bond strength.

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Authors EST and MNS designed the study, performed the statistical analysis, wrote the protocol and wrote the first draft of the manuscript. Author EST managed the analyses of the study and managed the literature searches. All authors read and approved the final manuscript.

Introduction: A Class II malocclusion is a common orthodontic problem that may affect social acceptance and the self-esteem of the patient. The aim of the present study was to evaluate the effect of functional appliance therapy on the oral health-related quality of life (OHRQOL) of patients presenting with a skeletal Class II malocclusion due to mandibular deficiency. Methods: Forty-nine patients (11 to 14 years old) with a Class II malocclusion due to mandibular deficiency were included as the experimental group. A control group of 49 subjects was selected from school children without malocclusion. The Child Oral Impact on Daily Performance (Child-OIDP) index was administered, repeated and differences were evaluated following functional therapy using the Clark Twin Block appliance. Results: At baseline, the most common oral impact on daily performance in the experimental group was emotional stability (35 patients, 71.4%) and smiling without shame (34 patients, 69.4%), which respectively decreased to 12.2% (six cases) and 20.4% (10 cases) after functional therapy. The mean (±SD) of the Child-OIDP Overall Impact score in the experimental group at baseline was 25.94 (±17.84), which significantly decreased to 2.77 (±2.09) after therapy (p < 0.001). Conclusion: Functional therapy using the Clark Twin Block appliance had a significant effect in improving OHRQOL of children presenting with mandibular deficiency.