الفهرس 
Shaping AbilityOnly 14 pages are availabe for public view
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Abstract
Over the decades, evolutional changes have been introduced for the Ni-Ti rotary files to facilitate the shaping and cleaning ability for the curved canals; these changes have included the design and the alloy itself. TFAdaptive is considered to be one of these recently introduced files that have unique features of being with R-phase technology, adaptive motion.
This study aimed to evaluate the effect of the Twisted File Adaptive and ProTaper Next and Twisted File rotary Ni-Ti files regarding the shaping ability via assessment of canal centering ability and canal curvature as well as its cleaning efficiency via assessment of the percentage of surface area covered with debris. The percentage of change in canal curvature, the Mesiodistal transportation and centering ability were assessed by comparing pre- and post- instrumentation measurements taken on CBCT images, while the canal cleanliness was evaluated using the stereomicroscope. Sixty human permanent mandibular molars were used in this study. Access cavities were done; then special measures were taken to ensure standardization and reproducibility of CBCT images.
Samples were classified into two main groups (n=30) according to method of evaluation. group I: shaping evaluation and group II: cleaning evaluation. Each group was further subdivided into three different subgroups (n=10) according to instrument used for root canal preparation .Subgroup A: TF Adaptive, Subgroup B: Twisted File, Subgroup C: ProTaper Next.
Shaping ability assessment was through using CBCT images analysis: Change in canal curvature was assessed by comparing pre- and post- CBCT images in the sagittal sections while measurements to assess in two direction Mesio-distal &Bucco-lingual transportation and centering ability were taken on the axial sections at three levels (2,5 and 8 mm). Data were collected then statistical analysis was performed. Canal cleanliness assessment: Longitudinal sections were photographed using the stereomicroscope then images were analyzed using image J software to measure the percentage of the surface area covered in debris at the coronal, middle and apical thirds.
Concerning the change in canal curvature the results showed statistically significant difference between the adaptive motion and the continuous rotation favoring Adaptive one also there was significant Difference favored Twisted File design and metallurgy R-phase technology. Concerning Mesio-distal transportation and centering ability the results showed very comparable results that always favored the Adaptive technique when statistically significant results were recorded.
Concerning the canal transportation, TFAdaptive showed no significant difference between both Dimension which told us that dentin cutting was linear in both directions at all cut levels in MD and BL dimensions. While PTN showed higher significant difference for BL dimension at 2 mm cut level and Twisted File cut dentin in MD direction more than BL.