title: Sealing root canals with low-viscosity resins in vitro: a scanning electron microscopy study of canal cleansing and resin adaption.
abstract: Low-viscosity resins of the fissure sealant type have been suggested in the literature as having potential for use as root canal filling materials. A low-viscosity resin may seal a root canal by flowing into clean dentinal tubules after smear layer removal. This investigation with scanning electron microscopy examines the efficacy of two methods of root canal preparation and the effectiveness of different chemicals on smear layer removal. Ultrasonic preparation with 0.25% sodium hypochlorite solution and final agitation with 50% citric acid solution were found to produce a very clean canal wall, free of smear layer in coronal and middle parts. However, low-viscosity resin used in conditions that aimed to simulate in vivo conditions failed to penetrate open dentinal tubules to a significant extent. On the basis of these observations made with scanning electron microscopy, low-viscosity resins would not seem suitable as root canal filling materials, because they are unlikely to form a satisfactory adaption to the canal wall. In addition, if treatment fails, these resins are impossible to remove from a root canal without much destruction of tooth substance.
authors.affiliation: Department of Restorative Dentistry, Charles Clifford Dental Hospital, Sheffield, England.
authors.forename: A
authors.initials: A
authors.lastname: Rawlinson
mesh_terms: D002951:Citrates / Q000008:administration & dosage; D019343:Citric Acid; D001840:Dental Bonding; D003804:Dentin / Q000648:ultrastructure*; D006801:Humans; D008855:Microscopy, Electron, Scanning; D010895:Pit and Fissure Sealants; D011670:Pulpectomy; D012117:Resins, Synthetic; D012387:Root Canal Filling Materials; D012388:Root Canal Irrigants / Q000008:administration & dosage; D012973:Sodium Hypochlorite / Q000008:administration & dosage; D013499:Surface Properties; D014464:Ultrasonic Therapy; D014783:Viscosity
chemical_list: D002951:Citrates; D010895:Pit and Fissure Sealants; D012117:Resins, Synthetic; D012387:Root Canal Filling Materials; D012388:Root Canal Irrigants; D019343:Citric Acid; D012973:Sodium Hypochlorite