Novel methodology to evaluate the effect of residual moisture on epoxy resin sealer/dentine interface: a pilot study

Gibby SG, Wong Y, Kulild JC, Williams KB, Yao X, Walker MP. Novel methodology to evaluate the effect of residual moisture on epoxy resin sealer/dentine interface: a pilot study. International Endodontic Journal 44, 236–244, 2011. Aim To evaluate the sealer/dentine interface associated with an epoxy resin sealer using the combination of Goldner’s trichrome stain (GTS) and scanning electron microscopy (SEM) to verify the use of the experimental methodology. Methodology Extracted human maxillary incisors (6) were subjected to root canal treatment. Subsequent to pulp removal, canal instrumentation and smear layer removal using EDTA and NaOCl, teeth were randomly and equally assigned to a ‘wet’ or ‘dry’ group. The ‘dry’ group was desiccated (95% ethanol/suction/paper points/air‐drying), whilst the ‘wet’ group was treated with a saline rinse/suction/single paper point. Canals were then filled with an epoxy‐based resin sealer and warm vertical gutta‐percha compaction. After 7‐day storage at 37 °C, roots from each group were sectioned into apical, middle and coronal horizontal subsections that were cut and split into paired halves and evaluated with GTS or SEM. With GTS sections, hybrid layer and sealer tubular penetration were measured (n = 15 measurements/intracanal location/condition) and evaluated using a two‐factor repeated measures analysis of variance. The SEM qualitative analysis of paired sections was included as a complementary confirmation of GTS analyses. Results In dry and wet groups, there was no conspicuous sealer/dentine interface hybrid layer, irrespective of canal location. However, dry specimens exhibited more uniform sealer distribution with deeper tubular penetration in the coronal and middle third (P