Using the push-out test, this study evaluated the bond strength of the composite resin Z250 (3M/ESPE) photoactivated with the XL2500 (3M/ESPE) quartz-tungsten-halogen light-curing unit with different curing protocols: soft-start (150 mW/cm² for 2 s (S2), 3 s (S3), 5 s (S5), 10 s (S10) or 15 s (S15), followed by 700 mW/cm² for 15 s; pulse-delay (150 mW/cm² for 2 s (P2), 3 s (P3), 5 s (P5), 10 s ...

PURPOSE This in-vitro study evaluated shear bond strength and analyzed, via scanning electron microscopy, enamel prepared for pit and fissure sealant placement. Various surface pretreatment methods were conducted prior to short-term (72-hour) and long-term (120-day) analysis. METHOD Six treatment groups of 14 teeth, having 28 bonding surfaces (buccal and lingual) were treated. Cylinders of De...

AIM To compare and evaluate few physical properties of epoxy resin, resin-modified gypsum and conventional type-IV gypsum die material. MATERIALS AND METHODS In the present study, dimensional accuracy, surface detail reproduction and transverse strength of three die materials like epoxy resin (Diemet-E), resin-modified gypsum (Synarock) and conventional type-IV gypsum (Ultrarock) are analyzed...

To understand and model the thermomechanical response of Nitronic-50 stainless steel, uniaxial compression tests are performed on cylindrical samples, using an Instron servohydraulic testing machine and an enhanced Hopkinson technique. True strains exceeding 60% are achieved in these tests, over the range of strain rates from 0.001/s to 8000/s, and at initial temperatures from 77 K to 1000 K. T...

The purpose of the study was to evaluate the load output of a pressure sensor in the presence of liquid saturation in a controlled environment. We hypothesized that a calibrated pressure sensor would provide diminishing load outputs over time in controlled environments of both humidified air and while submerged in saline and the sensors would reach a steady state output once saturated. A consis...

The skin of squamates consists of a keratinized epidermis divided into thick scale and thinner, folded interscale regions underlain by a dermis containing a complex array of fibrous connective tissues. We examined the skin of the lower jaw of watersnakes (Nerodia sipedon) to determine how skin morphology changes when highly stretched during ingestion of large prey. Video records of skin behavio...

PURPOSE This study evaluated, in vitro, the capacity of a dentin bonding agent to improve the bond strength of orthodontic brackets using air abrasion enamel preparation. METHODS Each of the enamel surfaces received a different treatment prior to bonding procedures. Group 1 received acid-etched with 38% phosphoric acid for 30 seconds. Group 2 received acid-etched with 38% phosphoric acid for ...

AIM The present study was conducted to determine and compare the shear bond strengths of Conventional glass ionomer; Resin-modified glass ionomer; Polyacid-modified composite and Composite Resin, and to assess and determine the mode of failure (adhesive, cohesive, mixed). MATERIALS AND METHODS Occlusal dentin of 40 extracted human teeth were randomly divided into four groups of ten teeth, eac...

INTRODUCTION Flexure of a dental composite can be detrimental to the success of a restoration. Flexibility considerations are thus important when comparing dental materials to optimize the success of resin restorations. AIMS AND OBJECTIVES Flexibility of 5.6 x 18.0 x 2.0 mm3 experimental alumina/feldspar and SR ADORO dental composites specimens were compared. It was hypothesized that alumina/...

Coated archwires and ceramic brackets have been developed to improve facial esthetics during orthodontic treatment. However, their mechanical behavior has been shown to be different from metallic archwires and brackets. Therefore, the aim of this study was to compare the deflection forces in coated nickel-titanium (NiTi) and esthetic archwires combined with ceramic brackets. Material and Method...