Esem Analysis of Enamel Surface Morphology Etched With Er,cr:ysgg Laser and Phosphoric Acid: In Vitro Study

Abstract

Objectives: The aim of the present study was to evaluate the etching pattern of Er,Cr:YSGG and conventional etching on prepared samples of human enamel by environmental scanning electron microscope (ESEM). Materials and Methods: Forty five freshly extracted human upper premolars were used; the teeth had been extracted for orthodontic reasons and were collected and stored in a solution of 0.1% (wt/vol) thymol. The teeth were mounted vertically in a self-cure acrylic cylinder. One clinician prepared all the teeth, in each tooth, a 4x4 mm area was treated in middle third of the buccal surface. The teeth were divided into three groups according to type of etching techniques (n=15).Group(A): enamel etched with 37% phosphoric acid for 30 s, thoroughly rinsed with distilled water for 60 s and gently air dried.; Group (B): enamel was irradiated with Er,Cr:YSGG laser ablated with an energy output of 4.5 watt/30hz and Group (C):enamel was irradiated with Er,Cr:YSGG laser ablated with an energy output of 4.5 watt/20hz. In group b & c Er,Cr:YSGG laser (2.78 μm wavelength) used for 15 sec at 45degree angulations working distance 5mm on a square size 4x4mm on buccal surface. Micro-morphological changes of enamel surface were evaluated using an environmental scanning electron microscope at X250 & X1500 magnification. Results: In this study, laser with 30 Hz reveals a definite change in the surface of the enamel, most of the enamel prisms are interrupted showing an irregular outline. However laser with 20 Hz showed the ultra-structural appearance of enamel nearly similar to that of conventionally etched enamel with 37 percent phosphoric acid. Conclusion: Within the limits of this in vitro study, both conventional acid etching & laser 20 Hz etching showed nearly similar effect on enamel surface, so the laser-etching can be successfully used as an alternative to the conventional acid-etch. On the other hand laser 30 Hz etching failed to induce an effect on enamel surface comparable to that of acid etching and therefore can't be used as substitute for the conventional acid-etch.

Evaluating the effect of ER,CR.YSGG LASER and conventional acid etching on shear bond strength of composite on enamel of primary teeth (in vitro study)

“…4). Results of Scanning electron microscope (qualitative evaluation) [35] Micro-morphological changes of enamel surface were evaluated using an environmental scanning electron microscope at X250 & X3000 magni cation. SEM evaluations of the samples showed some different surface characteristics.…”

“…All the deboned surfaces of the specimens were evaluated by single operator to record the mode of failure using stereomicroscope. After examination, failure mode will be classi ed as cohesive within the substrate (enamel or composite resin), adhesive (between adhesive and enamel), or mixed (if adhesive and cohesive fractures occurred simultaneously) Scanning electron microscope (qualitative evaluation) [35] Two specimens from each group will be evaluated by SEM to examine the enamel surface topography (total specimens = 6).…”

Effect of Laser Etching Versus Self-Etching Adhesive and Conventional Acid-Etching Techniques on Shear Bond Strength, Microleakage and Penetration Depth of a Resin Based Pit and Fissure Sealant (An In Vitro Study)

“…Furthermore, laser decreases the percentage of calcium ion dissolution and so may increase enamel resistance to acid decalcification, and at the same time does not yield a smear layer. (42) Erbium:Yttrium-Aluminum Garnet (Er:YAG) laser (2,940 μm ) was used in the present study due to its properties of interaction with hard dental tissues caused by its affinity to water and hydroxyapatite allowing for "cold ablation" (43,44) . The Er:YAG laser produces a small spot of ablated tissue less than 1 mm in diameter so it is useful as a tool for enamel pretreatment and prevents unnecessary etching of enamel (45) .…”

Effect of Different Surface Treatments of Glass Fiber Posts on their Surface Roughness and Flexure Properties

“…As this explosion occurs in water, it is so-called a preparation induced by water. Therefore, a water spray is used for cooling [20], [21].…”