Evaluation of calcium hydroxide and zinc oxide eugenol as root canal filling materials in primary teeth

Author(s): Mani SA et al.
Journal: Journal of Dentistry for Children
Volume (number): n/a
Month, Year: March-April 2000
Major topic: Ca(OH)2 as a medicament in pulpectomies of primary molars
Minor topic(s): ZnOE application in pulpectomies
Type of Article: research article
Main Purpose: to evaluate Ca(OH)2 as a root canal filling material in primary teeth, using ZnOE as the control
Overview of method of research: 60 mandibular primary molars in 50 children (ages 4-9 years, with the majority being between 6-8 years) were endodontically treated in two groups: Control group - (Group 1 with ZnOE as medicament) and Experimental group – (Group 2 with Ca(OH)2 as medicament). Presenting symptoms (pain, tenderness to percussion, mobility) were recorded prior to treatment; radiographic evaluation was done to exclude teeth showing internal resorption, pathological external root resorption, or inadequate bone support. Any teeth with evidence of abscess were opened for drainage and the patient was placed on a 3-4 day course of antibiotics prior to proceeding with the root canal. 51 of the 60 teeth were treated in a single-sitting procedure, with the remaining 9 teeth being treated in two sittings due to uncooperative behavior of the patients. Once anesthesized, rubber dammed, debrided of carious material and accessed, the pulpal debris was removed with barbed broaches and the root canals were irrigated with 5% NaOCL. Working length was established to 1 mm short of the apex and confirmed with radiographs. The operators attempted to file along the outer wall to lessen the chance of perforation. The final irrigating solution was 0.5% I.V. metronidzaole solution. The canals were then filled with their assigned paste using lentulospirals. Access cavities were filled with a fast-setting ZnOE paste. Quality and extent of filling was then evaluated radiographically immediately post operatively, and then at 2, 4 and 6 months.
Findings: No statistical difference was found between the two groups in terms of adequate fill, over fill, or underfill of the canals. In the ZnOE group, 25% of the canals were overfilled, and of these canals, 33.3% showed completed resorption of the materials within 4 months while the remaining 66.7% showed partial or no decrease in overfill; of this last-mentioned group, 60% showed migration of the overfill material to the interradicular area. In the Ca(OH)2 group, complete resorption of material was seen at the first follow-up in any overfilled canal. This was a statistically significant difference. There was no statistically significant difference in the two groups in terms of failures (increase in radiolucencies at follow-up). Physiologic resorption in ZnOE teeth resulted in either the filling depleting at the same rate or slower. Physiologic resorption in the Ca(OH)2 teeth resulted in the filling depleting at the same rate or faster. An additional finding in the Ca(OH)2 group was that before root resorption, Ca(OH)2 began to deplete in 14 teeth either from the apical portion of the canal, vertical generalized pattern, or from the pulp chamber area without involving the root canals.
Key points/Summary: A success rate of 86.7% in the Ca(OH)2 group and 83.3% in the ZnOE group was achieved. This was not statistically significant. In this study ZnOE did not contain a fixative as it has in previous studies. The authors argue against fixative use based on their successful study results, stating that fixatives may cause a foreign body reaction. Ca(OH)2 has irritant nature that destroy cells in the immediate vicinity and then stimulates cells further away to respond with calcification, due to its alkaline property .
Assessment of article: Well-presented research