Morphological Changes in Coated Nd-YAG Laser Enamel

1993 IAPD/ASDC MEETING 1993/ October 15 Chicago Illinois MORPHOLOGICAL CHANGES IN COATED ND-YAG LASED ENAMEL CORPAS PASTOR, L. ELÍAS-BONETA, A. VILLALBA MORENO, J. (School of Dentistry, U. Puerto Rico & U. Granada-Spain) ABSTRACT The objetive of this pilot study was to: (1) Evaluate with scanning electron microscopy (s.e.m.) the enamel surface alteration microscopic patterns after laser etching and acid etching technique, and (2) suggest the Nd-YAG laser power output necessary formeffective enamel-bracket bonding technique. 4 caries free human premolars were extrated and stored in saline wáter. Enamel etching were performed by using a Nd-YAG laser (American Dental Laser) with pulsed energy type and variable power (up to 3 W.) delivered by optic fiber. Every specimen underwent a different etching procedure. Samples were inmersed in tridistilled deionized wáter, rinsed, and sputtered with a layer of gold in an “ETEC gold sputtering BIO RAD, Mod. E 5200”, by using 18 mA. for 100 seconds. Morphology of each specimen was evaluated by s.e.m. The results show that the highest laser doses tried (20 pps/ 1.50 Watts), by using both primers, causes a fused enamel with melting and many pits of variable diameter, giving a drilled aspect. There are some microfractures that seemed to be narrowwer tan teh ones obtained with the 20pps /1.50 dosage. Higher numer of pits ad narrower microfractures appears by using black ink as laser primer. Hece, more research should be suggested about the clinical relevance of microfratures before using laser on patients, but for our purpose, double exposition at 15 pps/ .75 Watts with black ink as primer will be choosen as the laser dosaje to be used in the following bod strength test. Funded, in part. NIH award. RR-03051.