Odontoblast response to cavity preparation with Er:YAG laser in rat molars: an immunohistochemical study

• Published in: Odontology 2013-07, Vol.101 (2), p.186-192
• Main Authors: Shigetani, Yoshimi, Suzuki, Hironobu, Ohshima, Hayato, Yoshiba, Kunihiko, Yoshiba, Nagako, Okiji, Takashi
• Format: Article
• Language: English
• Subjects: Animals; Bromodeoxyuridine - metabolism; Dental caries; Dental research; Dentistry; HSP27 Heat-Shock Proteins - metabolism; Immunohistochemistry; Lasers; Medicine; Molar - radiation effects; Odontoblasts - cytology; Odontology; Oral and Maxillofacial Surgery; Original Article; Rats; Rats, Wistar
• ISSN: 1618-1247; 1618-1255
• DOI: 10.1007/s10266-012-0078-x

This study aimed to examine the dynamics of odontoblast-lineage cells following cavity preparation with erbium:yttrium–aluminum-garnet (Er:YAG) laser in rat molars. Cavity preparation was made with Er:YAG laser in the mesial surface of the maxillary left first molar of 8-week-old Wistar rats. Contralateral first molar served as unirradiated control. Immediately, 6 and 12 h and 1, 2, 3, 5 and 7 days after the lasing ( n  = 5, each), specimens were collected and processed for immunohistochemistry for heat-shock protein (HSP)-25 and nestin as markers for odontoblast-lineage cells. Cell proliferation assay using bromodeoxyuridine (BrdU) labeling was also performed. Unirradiated teeth showed HSP-25- and nestin-immunoreactivity in odontoblasts. At 6–12 h after irradiation, the odontoblastic layer was disorganized and some of odontoblasts lost the immunoreactivity to HSP-25 and nestin. At 1–2 days, however, HSP-25- and nestin-immunoreactivities in the odontoblast layer showed a noticeable recovery, resulting in the rearrangement of odontoblast-like cells intensely immunoreactive to HSP-25 and nestin at 3–7 days. BrdU-positive cells showed a significant increase at 2 days ( P