Factors affecting the time of onset of resorption in avulsed and replanted incisor teeth in children.

Resorption is the main reason for loss of replanted teeth. The outcome examined in this study is the timing of the onset of resorption. The effect of dichotomised dry and wet time intervals as well as the presence of additional crown damage and of contamination were determined. Of 84 replanted teeth, 67.5% developed resorptions. Twenty-eight had detectable additional crown damage with a more rapid onset being seen in these cases (P=0.009). The critical limit for dry time was 15 min (P=0.038) and significant differences persisted for greater limits also. Serial analysis of the association between the time of onset of root resorption and dichotomised wet time variables failed to yield any significant associations. There was visible contamination detected in 32 teeth and these exhibited a more rapid onset of resorption than the other cases (P=0.030). Teeth with inflammatory root resorption (12.8%) had a more rapid onset of resorption than those that developed replacement resorption (54.7%) (P<0.001). It is concluded that the risk of early resorption is increased in teeth that have additional damage or have contamination, or are kept in dry conditions for longer than 15 min.