effect of different powers of Er:YAG laser treatment on surface morphology of an indirect composite resin: SEM evaluation

Indirect composites are developed to overcome the shortcomings of direct composites but, the adhesion of resin cements to indirect composites is still difficult. The purpose of this study was to evaluate the surface morphology of indirect resin composite treated by different powers of Er:YAG laser using Scanning Electron Microscopy [SEM]. Indirect resin composite blocks [GC Gradia DA2, Japan] with 15× 10 × 10 mm dimensions were made according to manufacturer's instructions [n=7]. The bonding surface of these blocks were polished, then the samples were divided to seven groups as follow: Erbium-Doped Yttrium Aluminum Garnet [Er:YAG]laser with output power of 2, 3, 4, 5, 6,7 W [frequency of 20 Hz, very short pulse] and no treatment. Then, the surfaces were evaluated by scanning electron microscope. The surface treated by Er:YAG laser showed a porous surface. But the amount and pattern of these irregularities differ in each group which may produce micromechanical retention compared to control group with no treatment. Er:YAG laser can be used as an alternative technique for surface treatment and roughening of indirect resin composites

Effect of laser treatment on surface morphology of indirect composite resin: scanning electron microscope [SEM] evaluation

The aim of this study was to evaluate and compare the Scanning electron microscope [SEM] of indirect composite conditioned by Erbium-Doped Yttrium Aluminum Garnet [Er:YAG] laser, Neodymium-Doped Yttrium Aluminium Garnet [Nd:YAG] laser and Carbon Dioxide [CO[2]] laser. 18 indirect composite blocks [GC Gradia DA2, Japan] with 15 x 10 x 10 mm dimensions were made. The bonding surface of these blocks were polished, then the samples were divided into six groups as follow: Er:YAG laser with output power of 0.5 W and frequency of 10 Hz, Nd:YAG laser with output power of 0.25, 0.5 W and frequency of 10 Hz, CO[2] laser with output power of 0.5 W and frequency of 10 Hz and 5 Hz, and no treatment. Then, the surfaces were evaluated by SEM. Irregularities were observed in Er:YAG laser samples compared to control group that produced suitable retention for adhesion of cements. Nd:YAG and CO[2] lasers showed melting areas. Among different lasers, Er:YAG laser can be used as an alternative technique for surface treatment of indirect composites