RESUMO
AIM: To evaluate apical transportation and centring ability during root canal preparation in mesial root canals of mandibular molars associated with ProTaper Gold (PTG), ProDesign S (PDS), Hyflex CM (HCM), Hyflex EDM and ProDesign Logic (PDL). METHODOLOGY: Sixty mandibular first molars with two separate canals in the mesial root were selected after root anatomy pairing by microcomputed tomography (microCT). The teeth were randomly divided into five groups (n = 24); the root canal volume was calculated to ensure sample homogeneity. All the root canals were prepared up to size 25 in accordance with the instructions of each rotary system manufacturer. After root canal preparation, the teeth were scanned by microCT to analyse apical transportation, root canal centralization and the pre- and post-preparation root canal volume at the apical and cervical levels. Kruskal-Wallis and Dunn tests were used for comparisons amongst groups for transportation values. For volume changes, the parametric ANOVA and Tukey's tests were used RESULTS: There were no significant differences in apical transportation amongst the rotary systems (P > 0.05). All the systems created apical transportation; values ranging from 0.031 mm (PDL) to 0.072 mm (PTG), and enlargements between 39% (HCM) and 91.1% (PDS) were observed. In relative to cervical transportation, significant differences were observed amongst the systems (P < 0.05). Mean transportation values between 0.07 mm (HCM) and 0.172 mm (PTG) were found, with enlargements between 35.4% (HCM) and 51.5% (PDS). CONCLUSION: All the thermally treated systems resulted in similar apical transportation. In the cervical region, the Hyflex CM and Prodesign Logic systems were associated with more centred preparations.
Assuntos
Ligas Dentárias/química , Instrumentos Odontológicos , Níquel/química , Preparo de Canal Radicular/instrumentação , Titânio/química , Cavidade Pulpar/diagnóstico por imagem , Desenho de Equipamento , Temperatura Alta , Humanos , Técnicas In Vitro , Teste de Materiais , Dente Molar , Propriedades de Superfície , Microtomografia por Raio-XRESUMO
AIM: To evaluate canal transportation and centring ability of ProTaper Next (PTN) and Twisted File Adaptive (TFA) systems using microcomputed tomographic (micro-CT) imaging. METHODOLOGY: Twenty isthmus-containing mesial roots of mandibular molars were anatomically matched based on similar morphological dimensions using micro-CT evaluation (resolution of 14.25 µm) and assigned to two experimental groups (n = 10) according to the system used for root canal preparation: PTN and TFA groups. Then, the specimens were scanned again and the matched images of the mesial canals, before and after preparation, were examined at three cross-section levels (3, 5 and 7 mm from the apical end of the root) to analyse canal transportation and centring ratio. Independent-samples t-test was used to compare canal transportation and centring ratio between the groups. All statistical procedures were performed with a significance level set at 5%. RESULTS: Root canals prepared with either PTN or TFA systems had similar canal transportation and centring ratios at all levels (P > 0.05). CONCLUSION: PTN and TFA had similar results regarding canal transportation and centring ability.