title: Effect of CO₂ laser irradiation on wound healing of exposed rat pulp.
abstract: This study examined the effects of direct pulp capping treatment using super-pulsed CO₂ laser preirradiation on the wound healing process of exposed rat pulp on days 1, 3, 7, 14, and 28 postoperatively. Group 1 was irradiated with a CO₂ laser and directly capped with a self-etching adhesive system. The laser was operated in super-pulse mode (pulse duration, 200 μs; interval, 5800 μs; 0.003 J/pulse). The irradiation conditions were a power output of 0.5 W, an irradiation time of 3 s, and repeat mode (10 ms of irradiation at 10-ms intervals for a total beam exposure time of 1.5 s), defocused beam diameter of 0.74 mm (approximately 20 mm from the exposed pulp surface), energy density of 0.698 J/cm² per pulse, total applied energy of 0.75 J, and an activated air-cooling system. Group 2 was capped with the self-etching adhesive system. Group 3 was capped with commercially available calcium hydroxide, and the self-etching adhesive system was applied to the cavity. The following parameters were evaluated: pulp tissue disorganization, inflammatory cell infiltration, reparative dentin formation, and bacterial penetration. The results were statistically analyzed using the Kruskal-Wallis test for differences among the groups at each observation period (P < 0.05). There were no significant differences among the experimental groups in any parameters at any postoperative period (P > 0.05). CO₂ laser irradiation was effective in arresting hemorrhaging but showed a tendency to delay reparative dentin formation compared with the application of calcium hydroxide.
authors.affiliation: Department of Operative Dentistry, The Nippon Dental University School of Life Dentistry at Niigata, 1-8 Hamaura-cho, Chuo-ku, Niigata, 951-8580, Japan. collagen@ngt.ndu.ac.jp.
authors.forename: Masaya
authors.initials: M
authors.lastname: Suzuki
authors.affiliation: Comprehensive Dentistry, The Nippon Dental University Niigata Hospital, Niigata, Japan.
authors.forename: Takahito
authors.initials: T
authors.lastname: Ogisu
authors.affiliation: Department of Operative Dentistry, The Nippon Dental University School of Life Dentistry at Niigata, 1-8 Hamaura-cho, Chuo-ku, Niigata, 951-8580, Japan.
authors.forename: Chikage
authors.initials: C
authors.lastname: Kato
authors.affiliation: Department of Operative Dentistry, The Nippon Dental University School of Life Dentistry at Niigata, 1-8 Hamaura-cho, Chuo-ku, Niigata, 951-8580, Japan.
authors.forename: Koichi
authors.initials: K
authors.lastname: Shinkai
authors.affiliation: Department of Operative Dentistry, The Nippon Dental University School of Life Dentistry at Niigata, 1-8 Hamaura-cho, Chuo-ku, Niigata, 951-8580, Japan.
authors.forename: Yoshiroh
authors.initials: Y
authors.lastname: Katoh
mesh_terms: D000818:Animals; D002126:Calcium Hydroxide / Q000627:therapeutic use; D002245:Carbon Dioxide; D003763:Dental Leakage / Q000517:prevention & control; D003782:Dental Pulp / Q000378:metabolism / Q000528:radiation effects*; D003785:Dental Pulp Capping / Q000379:methods*; D003789:Dental Pulp Exposure / Q000628:therapy*; D003809:Dentin, Secondary / Q000378:metabolism* / Q000528:radiation effects; D016326:Extracellular Matrix Proteins / Q000096:biosynthesis; D050958:HSP47 Heat-Shock Proteins / Q000096:biosynthesis; D006489:Hemostatic Techniques; D054020:Lasers, Gas; D008297:Male; D010750:Phosphoproteins / Q000096:biosynthesis; D051381:Rats; D017207:Rats, Sprague-Dawley; D019279:Resin Cements / Q000627:therapeutic use; D012387:Root Canal Filling Materials / Q000627:therapeutic use; D053773:Transforming Growth Factor beta1 / Q000378:metabolism; D014945:Wound Healing / Q000528:radiation effects*
chemical_list: C081635:Dmp1 protein, rat; D016326:Extracellular Matrix Proteins; D050958:HSP47 Heat-Shock Proteins; D010750:Phosphoproteins; D019279:Resin Cements; D012387:Root Canal Filling Materials; D053773:Transforming Growth Factor beta1; D002245:Carbon Dioxide; D002126:Calcium Hydroxide