Background: The aim was to study structure of lower incisor in rats of different ages after 60-day inhalation of epichlorohydrin vapours (EV) and administration of thiotriazoline (Th) and Echinaceae tinctura (ET) as medication.
Methods: The study involved 420 male rats of three ages. The animals were split into the groups: 1st group comprised control animals, the 2nd group comprised the animals that received inhalations of EV in dosage of 10 MPC as a single 5-hour exposure per day, 2rd group - inhalations of EV and intraperitoneal Th in dosage of 117.4 mg per kg, 4th group - inhalations of EV and intragastric ET in dosage of 0.1 mg of active substance per 100 grams of body weight. After EV discontinue cross-sections of the lower incisor sampled as a segment next to the second molar tooth were HE stained. Morphometry included measurements of odontoblast layer, pre-dentin, and mature dentin and mesio-distal size (V. Luzin, 2011).
Results: By the 1st day upon EV discontinue, width of odontoblasts layer, pre-dentin layer, dentin layer and mesio-distal size in young rats were lower than that of the controls by 12.83%, 11.35%, 11.47% and 10.70%. In mature rats all the values listed were lower by 12.56%, 9.74%, 9.56%, and in old rats 8.85%, 8.67%, 7.37% ? 8.95%. In readaptation period after EV discontinue, alterations gradually reduced in young and mature animals yet by the 60th day majority of the values were markedly lower than those of the controls and old animals yielded few signs of restoration. After administration of Th, restoration of dentin structures in young rats was registered from the 1st to the 30th day, in adult rats from the 1st to the 60th day, and in old rats - from the 15th to the 60th day. After administration of ET, positive effects in young and adult rats were observed from the 7th to the 60th day and in old rats from the 15th to the 60th day.
Conclusions: 60-day inhalation of EV results in inhibition of functional activities of dentin secreting structures of the lower incisor. Restoration of dentin structure well depended on age of animals. Young animals exhibited faster restoration while in old animals such manifestations were scarce. Administration of Th or ET resulted in restoration of structure of the lower incisor. Th appeared to be more effective than ET.
Disclosure: The authors declared no competing interests.