Influence of cavity preparation technique (rotary vs. ultrasonic) onmicroleakage and marginal fit of six end-root filling materials

ABSTRACT

Objectives: To evaluate in vitro the effect of cavity preparation with microburs and diamond-coated ultrasonic tipson the microleakage and marginal fit of six end-root filling materials.Study Design. The following materials were assessed amalgam (Amalcap), zinc oxide eugenol (IRM), glassionomer (Vitrebond), compomer (Cavalite), mineral particle aggregate (MTA) and composite (Clearfil). Cavitypreparation was performed with microburs or diamond ultrasonic tips in single-root teeth. The seal was evaluatedin two experiments a microleakage assay on the passage of dye to the interface; and a scanning electron microscopystudy and analysis of epoxy resin replicas, measuring the size of gaps in the interface between filling materialand cavity walls. Multifactorial ANOVA, multiple comparison test and Student’s t test were used for statisticalanalyses of the data, considering p<0.05 to be significant.Results: Clearfil and MTA achieved a hermetic seal. Leakage and interface gap size was greater with Cavalitethan with Clearfil and MTA, followed by Vitrebond and IRM. The worst seal was obtained with Amalcap. Theuse of diamond-coated ultrasonic tips improved the seal and reduced the gap when using materials that did nothermetically seal the cavity (Amalcap, IRM, Cavalite, Vitrebond). The preparation technique did not affectmaterials that achieved a hermetic seal (Clearfil, MTA).Conclusions: Clearfil and MTA obtained a hermetic seal due to their excellent marginal fit and are the mostrecommended materials for clinical use, taking account of their sealing capacity. Ultrasonic cavity preparationis preferable because it improves the seal and marginal fit of materials that do not achieve a hermetic seal of thecavity (Amalcap, IRM, Cavalite, Vitrebond) (AU)