ABSTRACT
BACKGROUND: Despite the recent increase in application of Er:YAG laser for various dental treatments, limited information is available regarding the contact tips. This study examined the changes in energy output and surface condition of quartz and sapphire contact tips after Er:YAG laser contact irradiation for tooth enamel ablation. MATERIALS AND METHODS: Ten sets of unused quartz or sapphire contact tips were employed for contact irradiation to sound enamel of extracted teeth. The teeth were irradiated with Er:YAG laser at approximately 75 J/cm(2)/pulse and 20 Hz under water spray for 60 minutes. The energy output was measured before and every 5 minutes after irradiation, and the changes in morphology and chemical composition of the contact surface were analyzed. RESULTS: The energy output significantly decreased with time in both tips. The energy output from the sapphire tips was generally higher on average than that of the quartz. The contact surfaces of all the used quartz tips were concave and irregular. Most of the sapphire tips also appeared rough with crater formation and fractures, except for a few tips in which a high energy output and the original smooth surface were maintained. Spots of melted tooth substances were seen attached to the surface of both tips. CONCLUSION: In contact enamel ablation, the sapphire tip appeared to be more resistant than the quartz tip. The quartz tips showed similar patterns of energy reduction and surface alteration, whereas the sapphire tips revealed a wider and more characteristic variation among tips. Lasers Surg. Med. 41:595-604, 2009. (c) 2009 Wiley-Liss, Inc.
Subject(s)
Aluminum Oxide/radiation effects , Energy Transfer/radiation effects , Laser Therapy/instrumentation , Lasers, Solid-State , Quartz/radiation effects , Tooth Preparation/instrumentation , Dental Enamel/radiation effects , Humans , Surface Properties/radiation effects , Tissue Culture TechniquesABSTRACT
OBJECTIVES: The purpose of this study was to investigate the DIAGNOdent values applicable as a guide for removal of outer layer of carious dentin with Er:YAG laser. METHODS: Carious dentin of human extracted molars was removed by bur with Caries Detector (Group 1: red stained dentin was left, Group 2: light pink stained dentin was left) and by Er:YAG laser with DIAGNOdent value as a guide (30>Group 3>21, 20>Group 4>11, 10>Group 5). The cavity floor dentin after removing carious dentin was examined using microradiograms, EPMA and SEM. RESULTS: The cavity floor dentin of group 1,3 showed the decreases in the degree of X-ray absorption. In group 2,4 and 5, decrease of Ca, P were not observed. The decrease of Mg was observed on the more superficial part of the cavity floor for group 3 than for group 4. CONCLUSIONS: When carious dentin was removed using Er:YAG laser, the carious dentin outer layer was ideally removed with DIAGNOdent values: 11-20. DIAGNOdent values: 11-20, could indicate the completion of outer layer removal of carious dentin with Er:YAG laser, but there are some problems that must be addressed before the clinical application.
Subject(s)
Dental Caries/radiotherapy , Dental Instruments , Dentin/ultrastructure , Laser Therapy , Aluminum/therapeutic use , Dental Caries/diagnostic imaging , Dentin/diagnostic imaging , Dentin/radiation effects , Erbium/therapeutic use , Humans , Radiography , Yttrium/therapeutic useABSTRACT
The purpose of this study was to investigate the contact probes of Er:YAG laser before and after tooth ablation. Three kinds of contact probe were prepared. The first was an unused probe (NE). The second was used to prepare 10 cervical cavities (KP). The third was a probe that was judged for an exchange by three dentists who had expertise with Er:YAG laser (EX). The surface observation and mapping analysis were performed. The contact surface of NE was a flat and smooth surface, only Si was observed. KP demonstrated an uneven surface, Si was observed throughout, with scattered indications of Ca and P. EX displayed regions of fracture along the edge and a surface exhibiting dissolved adherents in parts. It was suggested that micro-explosions have effects on not only the tooth substance, but also the contact surface of the probe.
