Effective ablation of dental hard tissues by means of the erbium-doped:yttrium-aluminum garnet (Er:YAG) laser has been reported recently, and its application to caries removal and cavity preparation has been expected. However, few studies have investigated the capability of the Er:YAG laser to treat caries. In the present study, the effectiveness of caries removal by using an Er:YAG laser in vitro was compared with that of conventional mechanical treatment. Thirty-one extracted human teeth with root caries were used. Half of the caries in each tooth was treated with the Er:YAG laser, and the other was removed with a conventional bur or was left untreated as a control. Laser treatment was performed by means of a combination of contact and non-contact irradiation modes with cooling water spray, with a new fiber delivery and contact probe system. Conventional bur treatment was conducted by means of a low-speed micromotor. Measurements of the time required for caries removal, histopathological observations of decalcified serial sections, scanning electron microscope (SEM) observations, and hardness measurements of the treated cavity-floor dentin were performed for each treatment. Due to the careful irradiation technique, a longer treatment time was required for the complete removal of carious dentin by the Er:YAG laser. However, the Er:YAG laser ablated carious dentin effectively with minimal thermal damage to the surrounding intact dentin, and removed infected and softened carious dentin to the same degree as the bur treatment. In addition, a lower degree of vibration was noted with the Er:YAG laser treatment. The SEM examination revealed characteristic micro-irregularities of the lased dentin surface. Our results show that the Er:YAG laser system is promising as a new technical modality for caries treatment.
Adrian JC, Bernier JL, Sprague WG (1971). Laser and the dental pulp. J Am Dent Assoc83(Jul):113-117.
2.
Ando Y., Aoki A., Watanabe H., Ishikawa I. (1996). Bactericidal effect of erbium YAG laser on periodontopathic bacteria. Lasers Surg Med19:190-200.
3.
Aoki A., Ando Y., Watanabe H., Ishikawa I. (1994). In vitro studies on laser scaling of subgingival calculus with an erbium:YAG laser. J Periodontol65:1097-1106.
4.
Bassi G., Chawla S., Patel M. (1994). The Nd:YAG laser in caries
5.
removal. Br Dent J177:248-250.
6.
Burkes EJ Jr, Hoke J., Gomes E., Wolbarsht M. (1992). Wet versus dry enamel ablation by Er:YAG laser . J Prosthet Dent67:847-851.
7.
Fox JL, Yu D., Otsuka M., Higuchi WI, Wong J., Powell GL (1992). Initial dissolution rate studies on dental enamel after CO2 laser irradiation. J Dent Res71:1389-1398.
8.
Frentzen M., Koort HJ (1990). Lasers in dentistry: New possibilities with advancing laser technology? Int Dent J40:323-332.
9.
Frentzen M., Koort HJ, Thiensiri I. (1992). Excimer lasers in dentistry: Future possibilities with advanced technology. Quintessence Int23:117-133.
10.
Fusayama T. (1988). Clinical guide for removing caries using a caries-detecting solution. Quintessence Int19:397-401.
11.
Goldman L., Hornby P., Meyer R., Goldman B. (1964). Impact of the laser on dental caries. Nature203:417.
12.
Goldman L., Gray JA, Goldman J., Goldman B., Meyer R. (1965). Effect of laser beam impacts on teeth. J Am Dent Assoc70:601-606.
13.
Harnirattisai C., Inokoshi S., Hosoda H., Shimada Y. (1992). Interfacial morphology of an adhesive composite resin and etched caries-affected dentin. Oper Dent17:222-228.
14.
Hibst R., Keller U. (1989). Experimental studies of the application of the Er:YAG laser on dental hard substances: I. Measurement of the ablation rate . Lasers Surg Med9:338-344.
15.
Jennett E., Motamedi M., Rastegar S., Frederickson C., Arcoria C., Powers JM (1994). Dye-enhanced ablation of enamel by pulsed lasers . J Dent Res73:1841-1847.
16.
Kayano T., Ochiai S., Kiyono K., Yamamoto H., Nakajima S., Mochizuki T. (1991). Effect of Er:YAG laser irradiation on human extracted teeth. J Clin Laser Med Surg9:147-150.
17.
Keller U., Hibst R. (1989). Experimental studies of the application of the Er:YAG laser on dental hard substances: II. Light microscopic and SEM investigations . Lasers Surg Med9 :345-351.
18.
Keller U., Hibst R. (1990). Ultrastructural changes of enamel and dentin following Er:YAG laser radiation on teeth. Proc SPIE1200:408-415.
19.
Keller U., Hibst R. (1991). Tooth pulp reaction following Er:YAG laser application . Proc SPIE1424:127-133.
20.
Keller U., Hibst R. (1993a). Effects of Er:YAG laser on enamel bonding of composite materials. Proc SPIE1880:163-168.
21.
Keller U., Hibst R. (1993b). Kariestherapie mit dem Erbium:YAG Laser-Erste Klinische Ergebnisse. ZWR102:804-807.
22.
Kinsersly T., Jarabak JP, Phatak NM, DeMent J. (1965). Laser effects on tissue and materials related to dentistry. J Am Dent Assoc70:593-600.
23.
Koort HJ, Frentzen M. (1992). YAG-lasers in restorative dentistry : A histological investigation. Proc SPIE1643:403-411.
24.
Kumazaki M. (1995). Removal of hard dental tissue (cavity preparation) with the Er:YAG laser. In: 4th International Congress on Lasers in Dentistry. Loh HS, editor. Bologna: Monduzzi Editore, pp. 151-157.
25.
Kumazaki M., Kumazaki M. (1994). Etching with the Er:YAG laser. J Jpn Soc Laser Dent5:103-110.
26.
Li ZZ, Reinisch L., Van de Merwe WP (1992a). Bone ablation with Er:YAG and CO2 laser: study of thermal and acoustic effects. Lasers Surg Med12:79-85.
27.
Li ZZ, Code JE, Van de Merwe WP (1992b). Er:YAG laser ablation of enamel and dentin of human teeth: Determination of ablation rates at various fluences and pulse repetition rates. Lasers Surg Med12:625-630.
28.
Lobene RR, Bhussry BR, Fine S. ( 1968). Interaction of carbon dioxide laser radiation with enamel and dentin. J Dent Res47:311-317.
29.
Matsumoto K., Nakamura Y., Mazeki K., Kimura Y. (1996). Clinical dental application of Er:YAG laser for class V cavity preparation. J Clin Laser Med Surg14: 123-127.
30.
Melcer J., Chaumette MT, Melcer F., Dejardin J., Hasson R., Merard R., et al. (1984). Treatment of dental decay by CO2 laser beam: Preliminary results. Lasers Surg Med4:311-321.
31.
Nelson JS, Orenstein A., Liaw LH, Berns MW (1989). Mid-infrared erbium:YAG laser ablation of bone: The effect of laser osteotomy on bone healing. Lasers Surg Med9:362-374.
32.
Niemz MH (1995). Cavity preparation with the Nd:YLF picosecond laser. J Dent Res74:1194-1199.
33.
Nuss RC, Fabian RL, Sarkar R., Puliafito CA (1988). Infrared laser bone ablation. Lasers Surg Med8:381-391.
34.
Paghdiwala AF (1991). Er:YAG laser hard tissue effects. In: Lasers in dentistry. Moretti M, editor. Westford, Massachusetts: Penn Well Publishing Co., pp. 63-75.
35.
Powell GL, Kelsey WP, Blankenau RJ, Barkmeier WW (1989). The use of an argon laser for polymerization of composite resin. J Esthet Dent1:34-37.
36.
Robertson CW, Williams D. (1971). Lambert absorption coefficients of water in the infrared. Opt Soc Am61:1316-1320.
37.
Roth KK-F, Duczynski EW (1995). Ablation of healthy and carious enamel and dentin by erbium:YAG laser irradiation . Proc SPIE1984:44-51.
38.
Sano H. ( 1987). Relationship between caries detector staining and structural characteristics of caries dentin. J Stomatol Soc Jpn54:241-270 (in Japanese).
39.
Scheinin A., Kantola S. (1969). Laser-induced effects on tooth structure. II. Microradiography and polarized light microscopy of dental enamel and dentine . Acta Odontol Scand27:181-192.
40.
Seka W., Featherstone JDB, Fried D., Visuri SR, Walsh JT (1996). Laser ablation of dental hard tissue: from explosive ablation to plasma-mediated ablation. Proc SPIE2672:144-158.
41.
Sekine Y., Ebihara A., Takeda A., Suda H. ( 1995). Pulpal reaction in dog following cavity preparation by Er:YAG laser. Proc SPIE1984:159-167.
42.
Sonntag KD, Klitzman B., Burkes EJ, Hoke J., Moshonov J. (1996). Pulpal response to cavity preparation with the Er:YAG and Mark III free electron lasers. Oral Surg Oral Med Oral Pathol81:695-702.
Takizawa M., Aoki S., Takase Y., Ishikawa T., Kumazaki M., Inoue M., et al. (1995). Clinical evaluation of Er:YAG laser for cavity preparation. Jpn J Conserv Dent38:1035-1047 (in Japanese).
45.
Visuri SR, Walsh JT Jr, Wigdor HA (1996a). Erbium laser ablation of dental hard tissue: Effect of water cooling. Lasers Surg Med18:294-300.
46.
Visuri SR, Gilbert JL, Wright DD, Wigdor HA, Walsh JT (1996b). Shear strength of composite bonded to Er:YAG laser-prepared dentin. J Dent Res75:599-605.
47.
Watanabe H., Ishikawa I., Suzuki M., Hasegawa K. (1996). Clinical assessments of the erbium:YAG laser for soft tissue surgery and scaling. J Clin Laser Med Surg14(2):67-75.
48.
White JM, Goodis HE, Setcos JC, Eakle WS, Hulscher BE, Rose CL ( 1993). Effects of pulsed Nd:YAG laser energy on human teeth: a three-year follow-up study. J Am Dent Assoc124(Jul):45-51.
49.
Wigdor HA, Abt E., Ashrafi S., Walsh JT Jr (1993). The effect of lasers on dental hard tissues. J Am Dent Assoc124(Feb):65-70.
50.
Wigdor HA, Walsh JT Jr, Featherstone JD, Visuri SR, Fried D., Waldvogel JL (1995). Lasers in dentistry. Lasers Surg Med16:103-133.
51.
Yamamoto H., Sato K. ( 1980). Prevention of dental caries by Nd:YAG laser irradiation . J Dent Res59:2171-2177.
