Response of human pulpal tissue to orthodontic extrusive applications

The aim of this study was to investigate histologically the human pulp resp onse to orthodontic extrusive force applications. In group 1, 20 teeth were extruded with the use of a fixed sectional orthodontic appliance. In group 2, 20 teeth were extruded by means of 1/4-inch 4.5-oz elastics. The test p eriods were 10 and 40 days. None of the teeth in the groups showed any infl ammatory reactions or reparative dentin formation at the test periods. Five teeth from the elastics group and two teeth from the sectional appliance g roup showed large and numerous pulp stones in the serial sections (17.5% of all cases). Seven teeth from the sectional appliance group and two teeth f rom the elastics group showed odontoblast aspiration into the dentin tubule s (22.5%). The results of the study showed that the extrusive forces applie d in this study did not cause significant pathological changes in human pul p tissue.