Evaluation of Curved Canal Transportation Using the Neoniti Rotary System with Reciprocal Motion: A Comparative Study

The ideal root canal preparation is where the original canal morphology is maintained during the biomechanical preparation. Preparation of curved canals has always been a challenge to clinicians. Better results have been suggested for a single NiTi instrument with reciprocating motion than the conventional continuous rotation method in the preparation of curved root canals. Although the Neoniti rotary system is not suggested to be used with reciprocal motion, running a pilot study, we found that it could be possible. The present study aimed to investigate if shaping curved canals using the Neoniti rotary system with reciprocal motion leads to better results in terms of root canal transportation. One hundred acrylic j-shape canal simulator endoblocks were used in this study. Five preparation sequences were applied: GPS followed by A1#20 (GPS + A1#20), GPS followed by A1#20 and then A1#25 (GPS + A1#20 + A1#25), GPS followed by A1#25 (GPS + A1#25), hand file followed by A1#20 (hand file + A1#20), and GPS followed by A1#20 (with reciprocal motion) (GPS + A1#20(reciprocal)). Pictures were taken from blocks once before and once after preparation from two dimensions. Before-and-after pictures were superimposed in Photoshop software. Measurements were performed in Digimizer. The number of autoreverses and pecking motions was recorded after reviewing the recorded videos. Data were analyzed in SPSS, version 26. A p value of less than 0.05 was considered statistically significant. The group GPS + A1#20 + A1#25 had more transportation compared with the others, at apical, middle, and coronal thirds not only in the frontal view but also in the lateral view. Other groups were not significantly different. The number of peckings and autoreverses was significantly less when A1#25 was used after GPS and A1#20. When A1#20 was used with reciprocal motion, it had less peckings compared with the same file with continuous rotation, and no autoreverses were observed in that group. Using Neoniti files with reciprocal motion might result in less instrument fatigue and favorable results, with respect to canal anatomy preservation. Using A1#20 before A1#25 also will decrease the stress on the instrument during preparation. However, this may lead to significantly more canal transportation.

Shaping ability of 2Shape and NeoNiTi rotary instruments in preparation of curved canals using micro-computed tomography

Background Various systems of nickel-titanium (NiTi) instrument have long been commercially available. However, the preparation of narrow and curved root canals has always been challenging. The purpose of this study was to compare the shaping ability of two NiTi systems (2Shape and NeoNiTi) in severely curved root canals with different morphological patterns using micro-computed tomography (Micro-CT). Methods A total of 22 human extracted permanent teeth of mandibular first molars, with the exact mesial angle of curvature of 25 and 35 degrees, according to Schneider’s technique, were distributed randomly into two groups (group I: 2Shape, group II: NeoNiTi) based on the rotary system used (n = 22). The groups were subdivided into two subgroups corresponding to the angle of canal curvature (25° and 35°) (n = 11). Canals were scanned using Micro-CT pre- and post-preparation to assess the volume of dentin removed; canal transportation; and canal centering ratio at 3, 6, and 9 mm from the apex. The Mann–Whitney U test was utilized to determine any significant differences between the two systems. The level of statistical significance was set at p < 0.05. Results There was no significant difference between the two groups in volume of dentin removed; canal transportation; and centering ability for 25° and 35° canal curvatures at 3, 6, and 9 mm from the apex (coronal, middle, and apical) thirds (p > 0.05). At the middle third, the NeoNiTi group demonstrated a statistically significant increase in volume of dentin removed for 35° canal curvatures compared to the 2Shape group. Conclusion Within the limitation of our in vitro study, 2Shape and NeoNiTi systems with severely curved canals were confirmed to be relatively safe in preparation and to respect original canal anatomy. Nevertheless, NeoNiTi instruments produced more centered preparation and minimal canal deviation compared to the 2Shape system.

Comparison of Canal Transportation and Centering Ability of One-G, EdgeGlidePath, and Neolix: A MicroComputed Tomography Study of Curved Root Canals

Aims. A glide path is created prior to root canal instrumentation by nickel-titanium (NiTi) rotary files to increase the efficiency and safety of cleaning and shaping. This study aimed to assess root canal transportation in use of different glide path files in curved canals. Materials and Methods. 30 sound mesiobuccal root canals of mandibular molars with 20° to 40° curvature were selected and randomly assigned to 3 groups of EdgeGlidePath (EGP, EdgeEndo), One-G (Micro-Mega), and Neolix (Neoniti). The specimens were scanned before and after glide path creation by microcomputed tomography (micro-CT). The pre- and postoperative micro-CT scans were superimposed, and the degree of canal transportation and centering ratio were measured at 1, 3, 5, and 7 mm distances from the apical foramen. Statistical Analysis. The data were analyzed by two-way and one-way ANOVA. Results. The effects of distance from the apical foramen and instrument type and the interaction effect of the two were not significant on the centering ability of the files or canal transportation. Conclusion. EdgeGlidePath, One-G, and Neolix files fabricated from the conventional NiTi alloy or heat-treated M-Wire alloy showed similar performance regarding centering ability and canal transportation in glide path preparation in curved canals.

Comparison of the canal transportation of ProTaper GOLD, WaveOne GOLD, and TruNatomy in simulated double-curved canals

Background In root canal preparations, it is important to maintain the original canal shape. However, it is difficult to accomplish this, especially due to the complex canal anatomy. This study aimed to compare the shaping ability of the ProTaper GOLD, WaveOne GOLD, and newly developed TruNatomy in simulated S-shaped canals. Methods The root canals of 60 S-shaped resin blocks were dyed using ink and photographed. The blocks were then randomly divided into three groups: group ProTaper GOLD (n = 20), WaveOne GOLD (n = 20), and TruNatomy (n = 20). The simulated canals were instrumented according to the NiTi file system and photographed again after being dyed with red ink. The pre- and post-preparation images were superimposed, and the amount of resin removed from both the mesial and distal sides of the canal measured up to 9 mm from the apical terminus, with a 1 mm increment. The preparation time was also calculated. A paired t-test was used to determine the degree of deviation at different levels within the groups. To compare the degree of transportation at different levels between the groups, one-way ANOVA and Kruskal–Wallis tests were performed according to the normality. Results TruNatomy showed a significant deviation between the mesial and distal sides of the canal only in the coronal area at 6, 7, 8, and 9 mm levels of the canal (p < 0.05). When comparing the amount of transportation in the 3 groups at 9 different levels, TruNatomy showed significantly less canal transportation than the other groups at the 3-and 5-mm levels of the canal (p < 0.05), while ProTaper GOLD showed the largest amount of transportation in the apical curved area at the 2 and 3 mm levels (p < 0.05). TruNatomy removed less resin than other groups in all sections (p < 0.05), while ProTaper GOLD removed slightly more resin than WaveOne GOLD; however, there was no significant difference (p = 0.043). Shaping time was the least for TruNatomy, followed by the WaveOne GOLD and ProTaper GOLD (p < 0.05). Conclusions TruNatomy maintained the original apical canal curvature in S-shaped curved canals better than ProTaper GOLD and WaveOne GOLD.

What’s new for the clinician? - Excerpts from and summaries of recently published papers

Endodontic files are used to remove intracanal pulpal tissues, microbial biofilm, and toxic by-products and to develop a continuously tapering canal while maintaining the canal geometry that ultimately allows for the delivery of irrigating solutions and intracanal medicaments as well as the three-dimensional filling of the root canal system. Historically, stainless steel hand files have been used to perform canal shaping. However, these files are stiff and associated with increased operator fatigue, and when used in the preparation of curved root canals, the restoring forces of the files tend to return the file back to its original shape, resulting in canal transportation.

Impact of Contracted Endodontic Access Cavity on Shaping Ability of Hyflex Electrical Discharge Machining Single File Using Cone Beam Computed Tomography: An Ex Vivo Study

AIM: The aim of the study was to evaluate and compare the effect of different access cavity designs, using cone-beam computed tomography (CBCT), on root canal transportation, and centralization performed on two rooted maxillary premolars. METHODS: Twenty maxillary premolars were randomly divided into two groups. In Group 1, traditional endodontic cavities (TECs) were prepared. In Group 2, contracted endodontic cavities (CECs) were prepared. Mechanical preparation was done by HyFlex electrical discharge machining (EDM) single file in both groups. CBCT imaging was performed pre- and post-root canal preparation for calculations of root canal transportation and centering ability. RESULTS: Data were analyzed using Mann–Whitney U test and Kruskal–Wallis test. For transportation, teeth with CECs showed the statistically significantly highest median amount of transportation, while as for centering ability, results showed no significant difference between both groups. CONCLUSION: Under the conditions of this study, HyFlex EDM prepared canals with different access cavity designs without significant shaping errors. TEC showed less transportation than CEC, while both TEC and CEC had no effect on the file centering ability.

Canal Transportation and Volumetric Dentin Removal Abilities of Ni-Ti Rotary File Systems in Curved Primary Root Canals: CBCT Study

Current improvements in nickel-titanium (Ni-Ti) rotary file systems have created a paradigm shift in the root canal therapy of primary teeth. Therefore, it is necessary to perform a comprehensive evaluation regarding the efficiencies of newly manufactured instruments for different parameters. The current study was conducted to evaluate the abilities of RaceEvo, R-Motion, ProTaper Gold (PTG) systems in curved primary root canals with regard to the patterns of canal transportation and volumetric dentin removal by using cone-beam computed tomography (CBCT). Two experimental sets were designed following the determination of experimental groups by using pre- and post-operative CBCT data: canal transportation and volumetric dentin removal. The highest amount of canal transportation was significantly detected in the PTG group in comparison to RaceEvo and R-Motion groups. When the mean values of volumetric dentin removal data were analyzed across all groups, the PTG group again exhibited the significantly highest value of dentin removal volumetrically, compared to RaceEvo, R-Motion and manual instrumentation groups. It is possible to state that R-Motion and RaceEvo rotary systems could be used as reliable alternatives without causing adverse mechanical effects and maintaining the original root canal anatomy of curved primary root canal systems compared with PTG rotary systems and manual instrumentation, with a high diagnostic sensitivity of CBCT in pediatric endodontics when the alternative methods are not adequate.

Comparison of Canal Transportation, Separation Rate, and Preparation Time between One Shape and Neoniti (Neolix): An In Vitro CBCT Study

Purpose. This in vitro study compared root canal preparation in curved mesiobuccal canals of molar teeth using either the One Shape™ or the Neoniti (Neolix) rotary NiTi single-file systems, assessing canal transportation, instrument separation and time required for preparation. Methods. Extracted maxillary and mandibular human molar teeth with mesiobuccal canals having apical angles of curvature between 25 and 35o were selected and embedded in acrylic resin blocks, and an initial CBCT was taken. The teeth were divided into two equal groups (n = 20), and the canals were cleaned and shaped using either Neoniti™ or One Shape™ engine-driven NiTi rotary files. Each individual instrument was used to prepare 5 canals. The time required for the preparation of each canal was recorded. Postpreparation CBCT scans were taken and used to determine the extent of canal transportation at levels of 2, 4, 6, and 8 mm from the apex. The Kolmogorov–Smirnov test for normality was applied, and then, datasets were compared using independent t-tests, with a threshold of P < 0.05 . Results. Neoniti rotary files caused significantly less canal transportation of the curved canals ( P = 0.0001 ). On the other hand, the time required for canal preparation was significantly shorter for One Shape ( P = 0.0001 ). No instrument separation was recorded in both groups. Conclusion. Based on these results, the Neoniti™ rotary file system is preferred because it maintains the original shape of curved root canals better than One Shape™; even though this benefit comes at the cost of an increase in preparation time in clinical practice, the better technical performance may be more important than a difference in procedural time.

Comparison of Shaping Ability between Continuous Rotary and Manual Instrumentations in Pediatric Endodontics

Objective: The aim of this in vitro study was to evaluate the efficacy of rotary EndoArt Ni-Ti Gold Pedo Kit and K-files in shaping ability, canal transportation, centering ability and instrumentation time in primary molars. Methods: For the study total of 30 extracted primary molars root with minimum 7mm root length were selected. Shaping of root canals in primary molars were done using the two systems, and CBCT and specialized software were used for scanning and analysis of pre-operative and post-operative to evaluate the groups for their shaping properties, apical transportation and preparation time in primary root canals. Results: No differences were found in canal transportation measures and instrumentation time between the two groups (p>0.05). The EndoArt group removed more dentin compared to K-file in all sides of the root curvature. The statistical differences were significant for coronal and middle third of the root (p<0.05). Conclusions: Under the conditions of this study, rotary EndoArt Ni-Ti Gold Pedo Kit provided more conical canals than K-files in primary teeth.

Evaluation of the Shaping Ability of Three Thermally Treated Nickel–Titanium Endodontic Instruments on Standardized 3D-printed Dental Replicas Using Cone-Beam Computed Tomography

Background and Objectives: The aim of the present study is to compare the efficacy of three root canal preparation systems in the shaping of 3D-printed root canal replicas of single rooted teeth. Materials and Methods: Sixty 3D-printed root canal replicas were produced and divided into three groups, each consisting of twenty samples. Each group was shaped with a different instrument: Reciproc Blue R25/08 (VDW GmbH, Munich, Gemany), WaveOne Gold Primary 25/07 (Dentsply Sirona, Ballaigues, Switzerland), and ProTaper Gold F2 25/08 (Denstply Sirona). To ensure the reproducibility of pre- and post-operative CBCT images of the root canals, the endodontic printed replicas were placed in a mould of silicon impression material. A cone-beam computed tomography (CBCT) software was used to compare pre- and post-instrumentation images collected at three levels of the root canal length: 3, 6, and 9 mm from the apical foramen. The amount of transportation, centring ability, and curvature angle after shaping were evaluated for each system. The results were statistically analysed and compared using one-way analysis of variance (ANOVA). Results: Regarding the transportation of the root canal after shaping, significant differences between groups at 3 mm (p = 0.010721) and 6 mm (p = 0.000046) were recorded in the mesio-distal direction, while in the bucco-lingual significant differences were only observed at 6 mm (p = 0.000554). Reciproc Blue removed more dentin from the mesial and buccal wall of the root canal. When evaluating the centring ability of the three systems, significant differences were observed between the groups at the level of 9 mm (p = 0.037258) in the mesio-distal direction, and at the level of 6 mm (p = 0.038197) in the bucco-lingual direction. Significant differences of the canal curvature angle after shaping were also observed between groups (p = 0.000001). Reciproc Blue straightened the curvature the most, while ProTaper Gold the least. Conclusions: All systems produced minor root canal transportation. No instrument was able to achieve a perfect centring preparation of the root canal. All systems produced a small degree of root canal straightening.