Energy output reduction and surface alteration of quartz and sapphire tips following Er:YAG laser contact irradiation for tooth enamel ablation.
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.


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.


CONCLUSIONS
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.
Department of Endodontics and Operative Dentistry, School of Life Dentistry at Tokyo, Nippon Dental University, Tokyo, Japan. info@egurodental.com
Toru
T
Eguro
Akira
A
Aoki
Toru
T
Maeda
Aristeo Atsushi
AA
Takasaki
Mitsuru
M
Hasegawa
Masaaki
M
Ogawa
Takanori
T
Suzuki
Kazuaki
K
Yonemoto
Isao
I
Ishikawa
Yuichi
Y
Izumi
Ichiroh
I
Katsuumi
D000537:Aluminum Oxide / Q000528:radiation effects*; D003743:Dental Enamel / Q000528:radiation effects; D004735:Energy Transfer / Q000528:radiation effects*; D006801:Humans; D053685:Laser Therapy / Q000295:instrumentation*; D053844:Lasers, Solid-State; D011791:Quartz / Q000528:radiation effects*; D013499:Surface Properties / Q000528:radiation effects; D046509:Tissue Culture Techniques; D019246:Tooth Preparation / Q000295:instrumentation*
D011791:Quartz; D000537:Aluminum Oxide