Immunohistochemical Study of Neural Elements in Rat Alveolus Following Tooth Extraction

Thosapol Piyapattamin*, Mayuree Sarai, Pattana Haputta and Pacharapol Samneang

ABSTRACT: The morphology of neural elements at the alveolar sockets after tooth extraction was assessed by means of immunohistochemistry for protein gene product 9.5 (PGP 9.5) at the light microscopic level. Under general anaesthesia, maxillary right second molars of 10-week-old Wistar rats were removed. The animals were perfusion-fixed immediately after tooth extraction or 7, 30, 90, or 180 days later. Frozen sagital cryostat sections of the decalcified maxillae were prepared and stained with the avidin-biotin complex method. Histological sections showed that alveolar sockets gradually exhibited numerous small blood vessels, osteoblasts and newly formed bone, suggesting healing processes of the post-operative wound. Throughout the experimental periods, no large PGP 9.5-immunoreactive nerve trunks were recognized. On day 7 after the tooth extraction, beaded nerve fibers were seen within the central portion and also distributed to the periphery of the healing area. They were more frequently detected on day 30, but tended to decrease in their number by day 90. Compared with those observed in the controls, Ruffini nerve endings around apical areas of the healing sockets displayed smooth and swollen contours on day 7. By day 30, no nerve endings with a morphology resembling Ruffini nerve endings were found. However, free nerve endings were noticeable in the healing areas of all animals. These results indicated that the tooth extraction caused changes in the morphology and number of nerve fibers and endings at the healing sites.

Download PDF

Faculty of Dentistry, Naresuan University, Amphor Muang, Phitsanulok 65000, Thailand.

* Corresponding author, E-mail: thosapolp@nu.ac.th

Received 6 Jan 2005, Accepted 18 May 2005