The quality of Thermafil obturations with different final apical tapers: a three-dimensional microcomputed tomographic comparative study.

AIM The aim of this study is to evaluate the influence of final canal taper on the sealing ability of Thermafil by using microcomputed tomography (micro-CT). MATERIALS AND METHODS Fifty-four single-rooted teeth were instrumented to apical size 40 taper 4, 6 and 8%. Teeth were divided into three groups. All teeth were filled with Thermafil (Dentsply,Tulsa Dental Products). Using micro-CT, roots were scanned and volume measurements of voids at 1, 3 and 5 mm from the apex were calculated using specialized CT software. Measurements were analyzed statistically with ANOVA followed by Bonferroni multiple comparison correction. RESULTS Data analysis showed that 0.08 preparations provided better results than 0.06 and 0.04% tapered samples especially at 1 mm from the apex. Mean percentage of voids were significantly higher with Thermafil taper 0.06% (p = 0.05). None of the root canals filled teeth were gap free. Root canal preparations with bigger taper exhibited less voids than smaller tapered preparations. CLINICAL SIGNIFICANCE In our daily practice, enlarging the apical third (last 3 mm) of root canals to an 8% taper gives a better sealing ability and thus long-term success for our root canal obturations.