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Objective: The aim of this study is to compare shear bond strength of orthodontic stainless steel brackets to resin composite surfaces In vitro using three different methods of surface treatment. Materials and methods: 60 composite resin discs, 6 mm in diameter and 2 mm in height, were prepared and aged by immersion in water for 4 weeks. After ageing, the specimens were randomly assigned to one of the following groups: (1) Control with no surface treatment, (2) 99 per cent Acetone, (3) methyl methacrylate monomer, (4) Diamond bur. The metal brackets were bonded to composite surfaces by means of an orthodontic adhesive. All specimens were stored in water for 1 week. Shear Bond Strength values were tested using a universal testing machine at a crosshead speed of 1 mm/minute, the brackets bases and corresponding RC discs were examined under stereomicroscope at 10X magnification for adhesive remnant evaluation. Shear bond strength values were analyzed using 1-way analysis of variance (ANOVA)), Adhesive remnant index scores were analysed using Chi-square test using Monte Carlo correction. Significance of the obtained results was judged at the 5% level (P ≤ 0.05). Results: The results of 1-way ANOVA for SBS means showed no statistical significant difference among the 4 groups (P = 0.564). groups showed a statistically significant difference (MCp = 0.039). Chi square comparisons of ARI scores showed statistically significant difference only between group 1 (control) with groups 3 (P1= 0.003) and group 4 (P1= 0.046) 65 Volume 48 -December 2015 CONCLUSIONSurface treatment with acetone, MMA monomer or roughening with diamond bur does not affect the SBS of RC stored in water for 4 weeks.

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AUSTHACTDissolution rate and particle size distribution of griseofulvin were determined after simple blending o r solvent deposition using colloidal silicon dioxide. Griseofulvin deaggregation i n simple blends and rnicroparticulate drug dispersion in solvent deposited samples, both determinants of drug dissolution rate, were a function o f silicon dioxide content. Solvent deposited samples scored impressively highly initial dissolution rates compared to corresponding simple blends. However, dissolution data thereafter were not encouraging. Drug particle size enlargment in griseofulvin rich samples and incomplete drug recovery from silicon dioxide rich samples were notable drawbacks in solvent deposition systems. Viscosity effects of silicon dioxide dispersion on griseofulvin dissolution were demonstrated. Simple blending with silicon dioxide w a s recommended as a means of promoting disso-795 Copyright 0 1983 by Marcel Dekker, Inc. 0363-9045/83/0905-0795$3.50/0 Drug Dev Ind Pharm Downloaded from informahealthcare.com by UB Giessen on 12/09/14 For personal use only. 796ABDALLAH, KHALAFALLAH, AND KHALIL lution rate of griseofulvin. Limitation of average particle size data determined by methods which do not discriminate between drug and insoluble carrier is discussed.