The effect of dowel space preparation on the apical seal of Resilon & Gutta-percha obturation materials. (An in vitro comparative study

Abstract

Aim: The aim of this in vitro study was to compare the effect of immediate versus delayed dowel space preparation using peeso reamers on the apical seal of roots filled by Gutta-percha with two types of resin based-sealers (AH26 and AH Plus) and by Epiphany obturation system.Methodology: Sixty freshly extracted human teeth with single and straight canals were used in this study. The roots were instrumented using the step-back technique, instrumentation was accomplished by using the Gates-Glidden drills with copious irrigation of 2.5% sodium hypochlorite and 17% solution of aqueous EDTA to remove smear layer. The roots were randomly divided into 3 main groups according to the type of obturation materials using lateral condensation technique (20 teeth for each group):Group A: Gutta-percha + AH26 root canal sealer.Group B: Gutta-percha + AH Plus sealer.Group C: Resilon+ Epiphany sealer+ prime. (Epiphany obturation system)Then each group divided into two subgroups according to the time of dowel space preparation either immediately after obturation or after one week. The external surfaces of all roots were coated by two layers of sticky wax except for the apical 2 mm and were then submerged in 2% methylene blue dye for 3 days at 37ºC. After that, all roots were longitudinally sectioned for linear measurement of dye penetration through the apical foramen using a stereomicroscope. The data obtained were analyzed statistically using ANOVA and Student t-tests.Results: Significantly less apical leakage in roots filled by gutta-percha with AH Plus than those filled by gutta-percha with AH26 and those filled by Epiphany obturation system for delayed dowel space preparation (P< 0.05) and there was a significantly less apical leakage in roots filled by Epiphany obturation system that prepared immediately after obturation than those received delayed preparation (P< 0.05).Conclusion: All the groups had apical leakage what ever the type of obturation material or time of dowel space preparation.