The influence of smear layer removal on primary tooth pulpectomy outcome: a 24‐month, double‐blind, randomized, and controlled clinical trial evaluation

Abstract

The effect of smear layer (SL) removal on primary tooth pulpectomy outcome has not been well elucidated. To determine the effect of SL removal on primary tooth pulpectomy outcome. This is a double-blind, randomized, and controlled clinical trial. Forty-eight patients were randomly divided into SL removal (G1 = 40 teeth) or smear layer nonremoval (G2 = 42 teeth) groups. Following the chemomechanical preparation with K-files and 2.5% sodium hypochlorite (NaOCl), teeth were irrigated with either 6% citric acid and 0.9% physiologic solution (G1) or only 0.9% physiologic solution (G2). Camphorated paramonochlorophenol was used as intracanal medication. At the second appointment, 1 week after, root canals were filled with zinc oxide-eugenol paste. Clinical and radiographical baseline criteria were stipulated equally for both groups. The success rate (G1 = 91.2%; G2 = 70.0%) was statistically different (P = 0.04) between the groups. In G2, the outcome was affected significantly by pulpal necrosis (P = 0.02), pre-operatory symptoms (P = 0.02), and periapical/inter-radicular radiolucency (P = 0.04). The pulpectomy outcome was improved by smear layer removal. The outcome for teeth with pulpal necrosis, pre-operatory symptoms, or periapical/inter-radicular radiolucency was significantly improved by removal of the smear layer.