Assessment of gingival mucosa of infant rats during teething.

AIM The aim of the present study was to perform a histological analysis of the gingival mucosa in infant rats undergoing the teething process. MATERIALS AND METHODS Eighteen Wistar rats between 8 and 15 days of life were distributed among three groups: group A--without teething; group B--eruption of incisors; and group C--eruption of incisors and molars. The samples included teeth and periodontal tissue from the region of the incisors and molars of each animal. Fragments were processed for histological analysis and submitted to immunohistochemical analysis. RESULTS In the 8-day-old rats, mild inflammatory infiltrate predominated with mononuclear cells in the pericoronal follicles of the incisors and molars. At 12 days of age, all animals exhibited moderate inflammation in the pericoronal follicles and epithelium of the incisors and mild inflammatory infiltrate with predominantly mononuclear cells in the molars. At 15 days of age, moderate neutrophilic exudate was found in the pericoronal follicles and epithelium of the incisors and molars. Immunohistochemical analysis revealed positivity for interleukin- 1b in the pericoronal follicles in the pre-eruption phase. CONCLUSION An inflammatory reaction with progressive intensity occurs during the teething process, the response of which is preceded by the release of interleukin-1b. CLINICAL SIGNIFICANCE Morphological proof of events that occur during teething that can affect the dynamics of the physiologic process manifesting as clinical symptoms.