OBJECTIVES To use the FT-Raman spectroscopy for evaluation the degree of polymerization of dental composite as a result of photo curing with a new light source in comparison to the conventional halogen light. MATERIALS AND METHODS In this study a new light source, based on a metal-halide lamp (TOPSPOT G12) was developed at NRC-Egypt for curing dental composites. Two groups of 108 composite sa...

AIM The purpose of this study was to compare the surface hardness of a hybrid composite resin polymerized with different curing lights. METHODS AND MATERIALS Two 3.0 mm thick composite resin discs were polymerized in a prepared natural tooth mold using: (1) a conventional quartz-tungsten halogen light (QTH- Spectrum 800); (2) a high-intensity halogen light, Elipar Trilight (TL)-standard/expon...

OBJECTIVES To determine the influence of the light curing units on the shear bond strength of orthodontic brackets. MATERIAL AND METHODS Seventy-two premolars were divided into six groups (n=12): Group I: brackets bonded with Transbond and polymerization with halogen light; Group II: Transbond and LED; Group III: Fuji Ortho and halogen light; Group IV: Fuji Ortho and LED; Group V: Fuji Ortho,...

Introduction: One factor affecting the degree of polymerization is the type of light-curing device. The aim of this study was to compare the effects of LED and QTH light curing units on the surface hardness of composite and compomer. Materials & Methods: In this experimental study, 30 samples of composite and compomer were divided into 3 groups of 10 each. One-half of the subgroups in each g...

This study evaluated the influence of bleaching protocols on intrapulpal temperature and fracture strength of the bleached teeth. Ninety maxillary incisors were assigned to 9 groups (n=10): G1: 35% carbamide peroxide (35% CP), G2: 38% hydrogen peroxide (38% HP), G3: halogen light, G4: LED-laser, G5: 35% CP + halogen light, G6: 38% HP + halogen light, G7: 35% CP + LED-laser, G8: 38% HP + LED-las...

OBJECTIVES The aim of this study was to compare the shear bond strength (SBS) of two different light sources under different thermal cycle frequencies. METHODS Ninety human premolar teeth were divided into six groups, in which three groups consisted of halogen groups - Group I was cured with halogen without thermocycle, Group II cured with halogen with 500 thermocycles, and Group III cured wi...

this study was designed to evaluate the effect of argon laser irradiation on development and progress of enamel demineralization around orthodontic brackets.fifty caries-free, intact human premolars were randomly assigned to one of the following five equal groups: groups 1 (control) and 2: the brackets were bonded using conventional halogen light for 40s and argon laser for 10s, respectively. t...

objective: shear bond strength is an important property inherent to the durability of tooth-colored restorative materials namely composite resins. it has been years that halogen light sources have been used for polymerization of composite resins. in recent years light emitting diodes (led) have been introduced for this purpose. with respect to their longer bulb life, needless of a filter and no...

PURPOSE The objective of this study was to compare the light transmittance of zirconia in different thicknesses using various light curing units. MATERIALS AND METHODS A total of 21 disc-shaped zirconia specimens (5 mm in diameter) in different thicknesses (0.3, 0.5 and 0.8 mm) were prepared. The light transmittance of the specimens under three different light-curing units (quartz tungsten ha...