Clinical evaluation of tooth sensitivity during cavity preparation with Er:YAG laser

International Congress Series 1248 (2003) 223 – 225 Clinical evaluation of tooth sensitivity during cavity preparation with Er:YAG laser Junji Tagami a,*, Masayuki Otsuki a, Toru Nikaido a, Masatoshi Nakajima a, Yasushi Shimada a, Masaomi Ikeda a, Hideaki Narusawa b, Wataru Yukitani b, Takashi Yamashita b, Teruo Toko b, Hisashi Hisamitsu b a Cariology and Operative Dentistry Graduate School, Tokyo Medical and Dental University, 1-5-45, Yushima, Bunkyo-ku, Tokyo 113-8549, Japan b Department of Operative Dentistry, School of Dentistry, Showa University, 2-1-1, Kitasenzoku, Ota-ku, Tokyo 145-8515, Japan Abstract The efficacy of a high-pulse Er:YAG laser in treating caries was evaluated clinically. Caries removal and cavity preparation were performed using an Er:YAG laser (Er-D1, Hoya Continuum, Japan) at 30 – 350 mJ/pulse, 20 or 30 pps without local anesthesia. The cavities were restored with adhesive resin composite according to the manufacturer’s instructions. After treatment, the patients were asked to express the level of pain and discomfort felt during cavity preparation with the Er:YAG laser by means of a Visual Analogue Scale (VAS). The mean VAS value for discomfort was 6.03 and female patients recorded a lower value than male patients ( P < 0.05). The mean VAS value of pain was 22.53 and a statistically significant tendency for elderly patients to record a lower value than younger patients was found ( P < 0.05). The mean value and the tendency were comparable to those obtained in a previous study in which caries removal and cavity preparation were performed using rotary cutting instruments and caries detection dye. Patients with sensitivity caused by a jet of air before the treatment gave a higher value for pain during the treatment than patients without any sensitivity before treatment ( P < 0.05). It was concluded that caries removal and cavity preparation for adhesive restorations could be performed using an Er:YAG laser with little or no pain or discomfort. D 2002 Published by Elsevier Science B.V. Keywords: Er:YAG laser; Clinical evaluation; Caries treatment; Pain; Visual Analogue Scale * Corresponding author. Tel.: +81-3-5803-5480; fax: +81-3-5803-0195. E-mail address: tagami.ope@tmd.ac.jp (J. Tagami). 0531-5131/02 D 2002 Published by Elsevier Science B.V. doi:10.1016/S0531-5131(02)01296-7 224 J. Tagami et al. / International Congress Series 1248 (2003) 223–225 1. Introduction It is widely believed that restorative treatment involving the use of an Er:YAG laser for the removal of caries and cavity preparation is not painful or is less painful compared with the conventional method using rotary cutting instruments. A high-pulsed Er:YAG laser apparatus has recently been developed, which enables the pulse rate per second (pps) to be increased to 30 pps. The purpose of this study was to evaluate the pain and discomfort experienced by patients during caries treatment using the newly developed Er:YAG laser in a clinical trial. 2. Materials and methods The protocol of the present clinical study was approved by the ethics committees for clinical studies at both university hospitals of Showa University, School of Dentistry, and Faculty of Dentistry, Tokyo Medical and Dental University. Each hospital accepted 33 patients for treatment, and the total number of the patients was 66. The average age was 43.6 years, varying from 16 to 75 years. Active carious lesions were treated using an Er:YAG laser apparatus (Er-D1, Hoya Continuum, Japan), with energy of 30 –350 mJ/ pulse and up to 30 pps. The caries treatment applied was fundamentally the same as the method established by Fusayama [1]. This technique involves the removal of only the outer layer of dentin caries leaving the inner layer of dentin caries, in which bacterial invasion is not observed and remineralization is expected after placement of the restoration. Removal of the outer layer of caries was guided by natural discoloration and/or staining with a caries detecting dye solution (Caries Detector, Kuraray Medical, Japan). After the cavity preparations, so-called adhesive restorations were applied using an adhesive resin (Clearfil SE Bond, Kuraray Medical, Japan) and resin composite (Clearfil AP-X, Kuraray Medical, or Palfique Estelite, Tokuyama Dental, Japan) according to the manufacturers’ instructions. Treatment was completed without any request for anesthesia from the patients. Table 1 VAS values of pain and discomfort of the patients recorded with each age group Age (N) Pain (S.D.) Discomfort (S.D.) 10 and 20 (16) 38.2 (25.3) 8.1 (7.4) 30 (16) 18.2 (20.1) 5.8 (15.3) 40 (6) 18.7 (11.3) 2.2 (4.0) 50 (15) 19.9 (22.8) 7.5 (12.8) > 60 (13) 14.9 (19.7) 4.0 (5.7) Table 2 VAS values of pain and discomfort in the groups of the patients with or without sensitivity of the tooth before the treatment Pain (S.D.) Discomfort (S.D.) With sensitivity (N = 8) Without sensitivity (N = 58) 41.8 (21.7) 8.4 (9.8) 19.9 (21.4) 5.7 (10.9) J. Tagami et al. / International Congress Series 1248 (2003) 223–225 225 After treatment, patients were asked to express the level of the discomfort and pain they had experienced by means of a Visual Analogue Scale (VAS). Sensitivity and other clinical symptoms were evaluated for up to 3 months after placement of the restorations. 3. Results The mean VAS value for discomfort was 6.0 and female patients recorded a significantly lower value than male patients ( P < 0.05 by Unpaired t test). The mean VAS value of pain was 22.5. When the values in each age group were analyzed using Kruskal –Wallis and Mann – Whitney U tests, a statistically significant tendency for elderly patients to give a lower value than younger patients was obtained ( P < 0.05, Table 1). Patients with sensitivity caused by a jet of air before the treatment recorded a higher value of pain during the treatment than patients without any sensitivity before treatment ( P < 0.05 by Paired t test, Table 2). 4. Discussion Regarding pain experienced during the treatment, the mean value and tendency were comparable to those obtained in a previous study [2] in which caries removal and cavity preparation were performed using rotary cutting instruments and caries detection dye. Because the VAS value of pain during the injection of local anesthesia is reported to be about 50 [3], caries treatment using an Er:YAG laser can be said to be less painful than an injection of local anesthesia. For some patients with sensitivity to a jet of air or cold water, local anesthesia may be necessary. References [1] T. Fusayama, Two layers of carious dentin: diagnosis and treatment, Oper. Dent. 42 (1979) 63 – 70. [2] H. Terano, A. Koiwa, M. Okuda, N. Inai, M. Otsuki, J. Tagami, Evaluation of pain during caries treatment with composite restoration, J. Dent. Res. 79 (abst. #1162) 289. [3] J. Tagami, T. Niakido, M. Otsuki, R. Foxton, How to reduce postoperative sensitivity with adhesive restorations, in: T. Ishikawa, et al. (Eds.), Dentin/Pulp Complex, Quintessence Publishing, Tokyo, 2001, pp. 78 – 83.