Long-term follow up of root canal treated primary molars

Root canal treatment (RCT) is commonly performed to preserve primary molars with an infected or necrotic pulp.

This study evaluates the long-term effects of RCT in primary molars on the development and eruption of their permanent successors.

This is a retrospective study of treatment of pulpectomised primary molars in a public dental clinic. All teeth were treated by the same operator using the same material (Endoflas F.S.) and the same method. Records of 194 patients with 242 pulpectomised primary molars (124 in 97 boys and 118 in 97 girls) met the inclusion criteria. The children's age at the time of treatment ranged from 5 to 11 years (mean 6.72). Follow-up time ranged from 6 to 113 months (mean 33.5).

Eight (3.3%) of the 242 primary molars presented a new radiolucent defect or enlargement of existing periapical radiolucency. Of the 106 molars followed until eruption of the permanent successor, none had radiographic pathological signs. Of 17 permanent teeth evaluated clinically, three were erupted into a rotated alignment, and one premolar presented hypocalcified defect in the enamel.

Failure of root canal treatment in primary molars may be evident from development of new radiolucent defects or enlargement of existing defects. No relationship was found between RCT in the primary molars and the appearance of enamel defects or the ectopic eruption of following permanent teeth.