On the mesial surfaces of the second molars in each rat, the following histometric measurements were performed: the distance of the CEJ to the coronal level of epithelial cells (JEc) (attachment loss); the distance of the CEJ to the alveolar bone crest (ABC) (the alveolar crest bone level); the distance of the apical level of epithelial cells (JEa) to the ABC (the CT attachment); and the region of collagen deposited connective tissue in a zone of 0.