introduction: the aim of this study was to compare the micro-shear bond strength of composite resin on superficial and deep dentin after conditioning with phosphoric acid and erbium-doped yttrium aluminum garnet (er:yag) laser. methods: thirty human molars were selected, roots were removed and crowns were bisected to provide a total of 60 half-crowns. specimens were ground to expose superficial...

novel edible emulsified films were made using pistachio globulin protein (pgp) and palmitic fatty acid at concentrations of 2, 4, and 6 % w/w protein by tween-80 and homogenization technique. addition of palmitic acid to the pgp filmogenic solution resulted in great reduction of wvp in the emulsified films (37-40 %). concentration of palmitic acid did not create significant difference (p>0.05) ...

a new model is proposed in this research to calculate the longitudinal strengthof unidirectional e-glass reinforced polymer composites exposed to sulfuricacid environment, using a micromechanics model. in the proposed method,it is assumed that the residual strength of the degraded composites under acidic environment can be calculated by knowing the degraded strength properties of the constituen...

o bjectives: providing reliable attachment between bracket base and zirconia surface is a prerequisite for exertion of orthodontic force. the purpose of the present study was to eval- uate the effect of four zirconium surface treatment methods on shear bond strength (sbs) of orthodontic brackets. mat erials and methods: one block of zirconium was trimmed into four zirconium sur- faces, which se...

background: polymerization of resin‑modified glass‑ionomers (rmgis) is mediated through two competing mechanisms: an acid‑base reaction and a light‑dependent resin polymerization. furthermore, pre‑conditioning with acid has resulted in an increase in enamel bond strength of some rmgis. this in vitro study evaluated the effect of pre‑conditioning and/or delayed irradiation on bond strength of th...

Stem and peduncle bending by the weight of the flower is one of the main postharvest problems in gerbera (Gerbera jamesonii Bolus.) and sometimes caused stem crushing or water loss. In this research, silicon and salicylic acid were applied to enhance the mechanical strength of inflorescence stem, and the results revealed that stem curving was decreased by silicon and salicylic acid treatments. ...

background: based on contradictory findings concerning the use of lasers for enamel etching, the purpose of this study was to investigate the shear bond strength of teeth prepared for bonding with er-yag laser etching and compare them with phosphoric acid etching. materials and methods: in this in vitro study forty – eight premolars, extracted for orthodontic purposes were randomly divided in t...

the protonation constant values of salicylic and 5-nitrosalicylic acid werestudied by a combinationof spectrophotometric and potentiometric methods at 25 °c in wide range of ionic strength. the ionicstrength of solutions was kept constant by sodium perchlorate as background electrolyte at 0.10 to 3.0 moldm-3. potentiometer was calibrated according to gran method at each of ionic strength. the p...

introduction: the aim of this study was to evaluate the compressive strength of calcium-enriched mixture (cem) cement in contact with acidic, neutral and alkaline ph values. methods and materials: the cement was mixed according to the manufacturer’s instructions, it was then condensed into fourteen split molds with five 4×6 mm holes. the specimens were randomly divided into 7 groups ( n =10) an...

Polymer concrete (PC) is a composite material prepared by resin and aggregates. Advantages of polymer concretes include rapid curing at ambient temperatures, high flexural and compressive strengths, excellent chemical resistance and low permeability. In this research, a comparative study was performed on degradation of polyester resin concrete in different chemical solutions. Polymer concrete s...