Minocycline impairment of both osteoid tissue removal and osteoclastic resorption in a synchronized model of remodeling in the rat.

In addition to their antibacterial effects, tetracyclines may inhibit interstitial collagenase activity and bone resorption. These properties were assessed morphometrically using minocycline (25 and 50 mg/kg/day given by the IM route) in a rat model of synchronized remodeling in which osteoclastic resorption peaks 4 days after the activating event (the extractions of the upper molars) along the antagonist mandibular cortex, a zone undergoing physiologically active formation. During the first 2 days of activation, minocycline at the two doses impaired very significantly the disorganization of both the osteoid seam and the layer of osteoblasts, a prerequisite to give osteoclasts access to the mineralized bone surface.

[Emergency treatment: coronal restoration with pulpal-dentinal protection. Splints].

The authors, explain the need of a pulpo-dentinal protection, and present the way to adopt in case of dental traumas, as well for hard tissues (coronal and radicular) and for non calcified tissues (luxations). This protection allows a cicatrisation of dento-periodontal tissues.

Changes in mast cell number during the activation phase of an induced synchronized remodeling sequence in the rat.

Increase in mast cell (MC) number has been reported in some pathological conditions with increased remodeling. However, it is not known whether MCs are involved in the physiological remodeling of bone. In the present study the possible variations in MCs were investigated during the activation phase in a rat model of synchronized remodeling.