RT - Journal of Clinical Pediatric Dentistry ID - 10.17796/jcpd.32.1.a57600rm6vrx3174 T1 - Analysis of Primary and Permanent Molars Prepared with High Speed and Ultrasonic Abrasion Systems A1 - Rafael De Lima Pedro A1 - Livia Azeredo Alves Antunes A1 - Áurea Simone Barrôso Vieira A1 - Lucianne Comple Maia K1 - Dental instruments K1 - Cavity preparation K1 - Ultrasound in dentistry K1 - Primary teeth K1 - Permanent teeth. Smear layer YR - 2007 SP - 49 AB -

The aim of this study was to compare high speed and ultrasonic systems with regard to both topography and smear layer formation in the cavity preparations of sound primary and permanent molars. Class I occlusal cavities measuring 2.00 x 2.00 x 2.00 mm were performed in 14 molars, equally divided into two groups (GI= 7 primary teeth and GII = 7 permanent teeth). High speed rotary instruments produced regular layers of enamel and dentin, despite the marked presence of grooves and microfractures on enamel surfaces. On the other hand, ultrasonic abrasion yielded more irregular surfaces in enamel and dentin, with a granular and wavy aspect, but without microfractures in enamel. Both types of dental substrates were found to have an intense smear layer formation, partially or even completely obliterating the dentinal tubules (p>0.05), irrespective of the instrument used. No difference was observed in either primary or permanent teeth as regards the amount of smear layer produced by high speed or ultrasonic abrasion instruments (p>0.05). It was concluded that with regard to the topography of cavity preparations, there were differences between the instruments used, irrespective of the dental substrate. Both systems allowed dense smear layer formation, which completely or partially obliterated the dentinal tubules of primary and permanent teeth.