Er:YAG Laser Effects on Enamel Occlusal Fissures: Anin VitroStudy

Abstract

This study evaluated by scanning electron microscopy (SEM) the morphological changes in occlusal fissure enamel, of permanent models, irradiated by Er:YAG laser using contact and noncontact fiberoptics in vitro. Previous studies have demonstrated the efficacy of Er:YAG laser for dental hard tissue removal and cavity preparation. The treatment of occlusal fissures in noncarious permanent human molars (n = 9) was carried out with Er:YAG laser (KEY Laser II) using handpiece no. 2051, noncontact, focused (12 mm), water spray-cooled, pulse energy 200 mJ, and frequency 2 Hz (group 1), and handpiece no. 2055 with a quartz fiberoptic 50/10, in contact, air cooled, pulse energy setting of 350 mJ and frequency 2 Hz (group 2) and 400 mJ/2 Hz (group 3). The specimens were sectioned, dehydrated in a graded series of aqueous ethanol, dried, and sputtering with gold. Morphological change analysis on occlusal fissures was performed by SEM. Group 1 showed removal of fissure debris and predominantly enamel etching-like patterns, and groups 2 and 3 showed irregular edges, melting, and recrystallization of fissure enamel, with a lava-like structure and bubble-like voids. The results of this in vitro study suggest that the irradiation of fissures by Er:YAG laser using a fiberoptics (contact and air cooled) produced melting and recrystallization of fissures enamel. Further studies are required with different energy parameters and water cooling to evaluate the thermal effects on teeth.

Effects of different types of adhesive systems on the microleakage of compomer restorations in Class V cavities prepared by Er,Cr:YSGG laser in primary teeth

“…Detrimental temperature increase in the pulp can cause the cells to deteriorate, leading to pulpal pain and sensitivity 56) . Other drawbacks pertaining to the use of burs include unnecessary removal of sound tooth tissue 58) and failed root canal treatments due to microbial infection 59) . Microorganisms inhabit the deep layers of dentin and can cause failures in the conventional treatment of infected root canals if they are not sufficiently removed by preparation and chemical disinfection of the root canal 59,60) .…”

Effect of acid etching and different Er:YAG laser procedures on microleakage of three different fissure sealants in primary teeth after aging

“…Some studies have demonstrated that the microroughened appearance of the surface morphology after laser irradiation on permanent enamel has indicated similarities to those obtained with conventional acid etching 14,15) . Furthermore, the irradiation of fissure enamel of permanent teeth with Er:YAG laser produced some morphological changes such as melting and recrystallization of fissure enamel 16) . In-vivo evaluation of dental materials has caused difficulties in clinical trials.…”

Structural Changes on Human Dental Enamel Treated with Er:YAG, CO2 Lasers and Remineralizing Solution: EDS Analysis

“…Nevertheless, the modification of organic matter has been reported as one of the mechanisms in laser-induced caries prevention (the organic blocking theory) . In laser therapy, several factors related to exposure need to be considered: the wavelength and energy density of the laser, the irradiation time, the focal distance, and water cooling www.intechopen.com Morioka, et al, 1991;Fried, et al, 1996;Featherstone, et al, 1998;Hossain, et al, 2000;Young, et al, 2000;Hsu, et al, 2000;Tisai, et al, 2002;Kato, et al, 2003;Matson, et al, 2002;Apel, et al, 2002Apel, et al, , 2004Apel, et al, , 2005Rodrigues, et al, 2004;Westerman, et al, 2002;Nammour, et al, 2005Cecchini, et al, 2005Liu, et al, 2006;Fried, et al 2006;Castelan, et al, 2007). Furthermore, to achieve additional prevention, special attention has focused on laser irradiation, topical fluorides and remineralizing solution associations, showing very promising results (Hossain, et al, 2002;Delbem, et al, 2003;Chin-Ying, et al, 2004;Tepper et al, 2004;Rodrigues, et al, 2004;Kwon, et al, 2005;Ana, et al, 2006;Westerman, 2006;Tagliaferro et al, 2007).…”

“…Although this laser was introduced into dentistry for the ablation of dental hard tissue , an early report (Kayano, et al, 1989) suggested an increase in acid resistance of the enamel adjacent to the ablated area. Later, several in vitro studies (Morioka, et al, 1991;Fried, et al, 1996;Hossain, et al, 2000;Cecchini, et al, 2005;Castelan, et al, 2007) on smooth dental enamel surfaces reported that Er:YAG irradiation promotes caries prevention as well as morphological enamel changes (Matson, et al, 2002;Cecchini, et al, 2005;Apel et al, 2005;). Furthermore, it was reported that both effects depend on the energy density of the laser, among other parameters, including irradiation time, focal distance, and water cooling (Morioka, et al, 1991;Fried, et al, 1996;Hossain, et al, 2000;Young, et al, 2000;Matson, et al, 2002;Apel, et al;Cecchini, et al, 2005;Liu, et al, 2006;Castelan, et al, 2007).…”