Neoniti Research Articles

The Evaluation of Debris and Smear Layer Generated by Three Rotary Instruments Neo NiTi, 2Shape and Revo_S: An Ex-vivo Scanning Electron Microscopic Study.

This study compared the cleaning effectiveness of NeoNiTi, 2Shape and Revo_S rotary instruments. Fifty mandibular molar mesial roots were selected with an angle of curvature less than 20 degrees divided into three groups (n=15). Five samples were selected as negative control group. In all three systems, the final file was 25, 6%. The score of debris and smear layer in three thirds (coronal, middle and apical) of the root canal walls were evaluated using scanning electron microscopic (SEM) magnification. The data were analyzed using the Kruskal Wallis and Mann Whitney U tests for intergroup comparison (P≤0.05) and Freidman and Wilcoxon signed-rank test was employed for intragroup comparison (P≤0.05). Residual debris of the 2Shape system in the apical region was significantly higher than the other two systems (P=0.039). Revo_S and 2Shape groups had significantly higher quantities of debris in the apical than the coronal region (P=0.029 and P=0.02, respectively). In the 2Shape group, the amount of mid-region debris was significantly higher (P=0.005) than the coronal. In inter-group comparison there was no significant difference in residual smear layer between the systems. In intra-group comparison in all three systems, the amount of smear layer in the coronal third was significantly higher than in the other two areas. (P=0.017, P<0.001 and P=0.032, respectively). 2Shape left the highest amount of debris in the apical region. The amount of debris in Revo_S and 2Shape groups in the apical region was significantly higher than in the coronal. The amount of smear layer in all three groups in the coronal area was higher than the middle and apical areas.

Comparative evaluation of fracture resistance of hyflex edm, neolix neo niti, protaper next and protaper gold files- an in-vitro study

Aim: The purpose of the present research was to assess the comparison of the fracture resistance ability of various endodontic files like- Hyflex EDM, Neolix Neo NiTi, Protaper Next and Protaper Gold. Methodology: All the instruments were subjected to fracture test using a stainless-steel artificial canal. Time required for fracture as well as number of cycles to failure was calculated at 5 and 8 mm distance from the end of root canal tip. The fractured surfaces were then visualized using electron microscope. The data was analysed using student t-test and Weibull reliability estimation. Results: Hyflex EDM OneFile instruments showed significantly greater cyclic fatigue resistance than protaper Gold Primary instruments as well as protaper next and neolix NiTi. A significant difference was found between the groups for the length of the fracture 5 mm from the tip (P &lt; 0.01). No significant difference was found between the groups for the length of the fracture 8 mm from the tip (P &gt; 0.01). Conclusion: Hyflex EDM OneFile demonstrated the highest performance in terms of cyclic fatigue resistance.

Micro-computed tomography assessment of dentinal microcracks after the preparation of curved root canals with rotary and reciprocal systems.

Root canal preparation with nickel-titanium (NiTi) instruments may lead to the formation of microcracks in the root canal wall. Vertical root fractures may initiate from dentinal cracks, and eventually necessitate tooth extraction. This study aimed to assess the effect of the instrumentation of curved root canals of mandibular molars with the 2Shape (2S) sequential rotary, EdgeFile® X1 (EFX1) reciprocating and NeoNiTi (NN) rotational single-file systems on the formation of dentinal microcracks with the use of micro-computed tomography (micro-CT). Thirty curved mandibular molar root canals were instrumented with the 2S, EFX1 and NN systems (10 in each group). The teeth underwent micro-CT before and after instrumentation. Next, the pre-instrumentation and post-instrumentation cross-sectional images were evaluated and compared for the detection of dentinal microcracks. The number of microcracks in each group was calculated and reported as percentage. The data was analyzed using the McNemar's test with the IBM SPSS Statistics for Windows software, v. 25.0 (α = 0.05). Out of the 29,280 cross-sectional images evaluated in this study, 11.5% showed dentinal microcracks (n = 3,362). On the post-instrumentation images, the frequency percentage of microcracks was 12.0% (n = 585) in the 2S group, 8.8% (n = 402) in the EFX1 group and 13.3% (n = 694) in the NN group. All of the microcracks detected on the post-instrumentation images were also present on the preinstrumentation images and no new microcracks were formed after root canal instrumentation with the aforementioned systems. Root canal instrumentation with the 2S, EFX1 and NN systems did not result in the formation of new dentinal microcracks.

Cutting efficiency and dentinal defects using two single-file continuous rotary nickel–titanium instruments

Aim: The aim of this study was to evaluate and compare the cutting efficiency and dentinal defect rates using two single-file continuous rotary nickel–titanium instruments. Materials and Methods: Thirty-two resin endo training blocks and 48 mesiobuccal roots of extracted human first lower molars were divided into five groups (16 for each group). Roots were checked for the homogeneities of root canal dimensions, thickness of dentin walls, and curvatures using images of X-ray radiographs on AUTOCAD software. Two groups of resin blocks and two groups of mesiobuccal canals were instrumented using two continuous rotary nickel–titanium instruments (Neoniti A1 and OneShape), the remaining group (control group) of mesiobuccal canals was left intact. The cutting efficiencies of instruments were quotients of the loss weights of specimens, and the time needed for instrumentation. ANOVA and post hoc Tukey tests were used to analyze the differences among the experimental groups. The cracks on the sectioned root surfaces at 3-, 6-, and 9-mm levels were recorded. Fisher exact test was used to analyze the differences among the experimental groups. Results: Cutting efficiency of OneShape was greater than that of Neoniti on both resin and human root canals (P 0.05). Conclusions: OneShape instrument was more efficient than Neoniti on both kinds of root canals. Both instruments created dentinal defects on root canal walls.