A comparative study to evaluate the effect of immediate versus delayed dowel space preparation on the apical seal of epiphany obturation system with different obturation techniques : an in vitro study

Abstract EN

Background : The aim of this in vitro study was to compare the effect of immediate versus delayed dowel space preparation using rotary instruments (peeso reamers) on the apical seal of roots filled with epiphany obturation system by two different obturation techniques: Lateral condensation technique and Thermo-plastic Injection technique (Obtura II).

Materials and Methods : Forty freshly extracted human teeth with single and straight canals were used in this study.

These teeth were cleaned and their crowns were removed at the cemento-enamel junction, the roots were instrumented using the step-back technique, instrumentation was accomplished by using the Gates-Glidden drills with copious irrigation of 2.5% NaOCL and 17% buffered solution of EDTA was used as the final rinse to remove smear layer.

All roots of all groups were obturated with epiphany obturation system and the roots were randomly divided into 4 groups (10 teeth for each group) : Group A (Lateral condensation technique + immediate dowel space preparation), Group B (Lateral condensation technique + delayed dowel space preparation), Group C (Thermoplastic Injection technique (Obtura II) + immediate dowel space preparation) and Group D (Thermo-plastic Injection technique (Obtura II) + delayed dowel space preparation).

The roots of groups A and C received dowel space preparation immediately after obturation using peeso reamers to a depth that left 5mm of the filling material apically while the roots of groups B & D received dowel space preparation after one week storage in 100% humidity condition at 37Cْ in an incubator.

The external surfaces of all roots were coated by two layers of sticky wax except for apical 2 mm and then were submerged in 2% methylene blue dye for 3 days at 37 C.ْ After that all roots were longitudinally sectioned for linear measurement of dye penetration through the apical forman using a stereomicroscope at X40 magnification with calibrated scale ocular grid.

Results : The results showed that for immediate dowel space preparation group C showed the lowest mean of dye leakage (1.525 mm) while for delayed dowel space preparation group D showed the lowest mean of dye leakage (2.335 mm).

Conclusion : Significantly less apical leakage in roots obturated by thermo-plastic Injection technique than those obturated by lateral condensation technique for both immediate and delay dowel space preparation and highly significant less apical leakage in roots received immediate dowel space preparation than those received delayed one despite the type of obturation technique.