The effect of procedures intended to alter the interstitial fluid pressure in the sockets of resected rat incisors on their eruption rate.

Eruption rates of resected incisors were measured while their sockets were kept open to the mouth. In other resected incisors, hypertonic solutions were placed in the pulp cavity, with the intention of drawing fluid by osmosis across the membrane separating the pulp cavity from the socket, to lower the pressures within the socket. These procedures slowed eruption when control resected incisors were erupting rapidly but not during their initial and final slow phases of eruption. The findings are consistent with there being two factors making resected incisors erupt, tentatively identified as the periodontal ligament and, when eruption is rapid, the interstitial pressures of the tissues in the socket.