Pulpectomy is, indicated for primary teeth with irreversibly inflamed or necrotic radicular pulps because of caries or trauma. The main aim of this trial was to evaluate the outcome of pulpectomy with smear layer removal versus no smear layer removal.

Patients were randomised to receive pulpectomy under rubber dam with either smear layer removal (G1) or no smear level removal (G2). 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. restoration was with composite resin, light-cured glass ionomer dental restorative material, or a preformed metal crown.

The authors reported  that:-

•  G1 showed a higher success frequency (91.2%; 31⁄ 34) when compared with G2 (70.0%; 28⁄ 40), with a significant difference between them (P = 0.04).
• 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).

However, it should be noted that figure 2 and table 4 in their paper reports that the success frequency should be  (93.9%; 31/33   for G1 and   (82.4%;28/34 ) at 24 months. This difference is not statistically different.

The authors concluded

 This study suggests that the smear layer removal improved the pulpectomy outcome in primary teeth in a 24-month period.

BARCELOS, R., TANNURE, P. N., GLEISER, R., LUIZ, R. R. and PRIMO, L. G. (2011), The influence of smear layer removal on primary tooth pulpectomy  outcome: a 24-month, double-blind, randomized, and controlled clinical trial evaluation. International Journal of Paediatric Dentistry. doi: 10.1111/j.1365-263X.2011.01210.x

Related reviews  and guidelines

American Academy of Pediatric Dentistry (AAPD). Guideline on pulp therapy for primary and immature permanent teeth. Chicago (IL): American Academy of Pediatric Dentistry (AAPD); 2009. 8 p. [107 references]

Nadin G, Goel BR, Yeung A, Glenny AM. Pulp treatment for extensive decay in primary teeth. Cochrane Database of Systematic Reviews 2003, Issue 1. Art. No.: CD003220. DOI: 10.1002/14651858.CD003220.