Inhibition of tooth eruption through calcium-phosphate ceramic granules in the rat.

This experiment investigated the reason for disturbances of tooth eruption through hydroxylapatite (HA) granules. HA granules of compact and porous structure were implanted in the pathway of erupting teeth in 14 five-day-old rats. The results demonstrate that the use of this material can result in tooth retention and malformed tooth crowns. Tooth crown malformation can be traced to the formation of ceramo-dentinous complexes which promote bacterial invasion of the pulp cavity, resulting in arrest of the tooth eruption process.