NiTi Rotary Systems Research Articles

OUTCOME EVALUATION OF ENDODONTIC TREATMENT WITH PROTAPER ROTARY INSTRUMENT SYSTEM ON MAXILLARY INCISORS

In recent years, thanks to the rapid advancement of science and technology and a better understanding of the anatomy of the root canal system, many new endodontic instruments and materials have been introduced with the desire to minimize complications in the process of preparing the root canal, help the cleaning and shaping process to complete well. It is noteworthy that the emergence of new endodontic files made of Nickel-Titanium alloy (NiTi files), which, according to the recommendations of manufacturers, make the preparation of root canals faster and more efficient, with a much simpler shaping technique than previous stainless-steel files. This is the topic that attracts great interest from clinicians. Therefore, it is necessary to conduct studies to evaluate these types of instruments. Over the years, there has been a lot of research on NiTi instrument systems carried out in the world, which mainly focused on the current types of rotary NiTi files. In Vietnam, although the NiTi instrument system appears a lot on the market and is increasingly employed by many dentists and endodontic experts, the amount of research on them is limited.
 Therefore, in order to contribute to more understanding and improve the effectiveness of endodontic treatment with niti rotary instrument systems we carry out the research: “Outcome Evaluation of endodontic treatment with Protaper rotary instrument system on maxillary incisors" with two aims:
 
 To evaluate root canal sealing results with cone beam computed tomography (CBCT)
 To evaluate the outcomes of maxillary incisor root canal treatment with the Protaper rotary instrument system.

Post-Instrumentation Dentinal Microcracks Induced by Two NiTi Rotary Systems with Increased Super Elasticity and Shape Memory: A MicroCT Comparative and Methodological Ex Vivo Study

This study aimed to determine the incidence of dentinal microcracks after instrumenting the root canals of maxillary premolars using two novel rotary instrumentation systems. Micro-computed tomography (microCT) scans and images generated by sectioning and observation with a stereomicroscope were used to assess the specimens. Twenty-two freshly extracted maxillary premolars were collected and the specimens were divided into two groups of eleven. The tested radicular shaping systems were XP-Endo shaper and TRUShape (i.e., single file). The specimens were scanned with microCT pre- and post-instrumentation, and the newly formed microcracks were detected. The post-instrumentation scans were also compared with images obtained by sectioning method and stereomicroscope inspection, comparing the incidence of microcracks in either microCT scans or images. The results identified an overall incidence of 0.49% of newly formed microcracks, with no statistically significant differences (p = 0.689) between the shaping systems (0.11% for TRUShape and 0.87% for XP-Endo shaper). There were statistically significant differences (p < 0.001) between the microcracks incidence in microCT scans and the sectioning method (16.6% more for the latter). In conclusion, the results show that neither TRUShape nor XP-Endo shaper created dentinal microcracks during root canal instrumentation. The sectioning method with stereomicroscope evaluation overestimates the presence of microcracks with a statistically significant difference compared to microCT scans.

Antibiofilm activity of ultrasonic and diode laser activated sodium hypochlorite, chitosan, and chlorhexidine: A confocal laser scanning microscopic in vitro study.

The aim of this study was to assess and compare the effect of ultrasonic and diode laser-activated sodium hypochlorite (NaOCl), chitosan, and chlorhexidine (CHX) on the removal of Enterococcus faecalis biofilm adherent to the root canal using a confocal laser scanning microscope (CLSM). Root canals in 112 single-rooted teeth were instrumented using a rotary Ni-Ti system. Biofilms of E. faecalis were generated based on an established protocol. Samples were randomly divided into three experimental (n = 28) and one control (n = 28) group based on the irrigation protocol employed and the three experimental groups were further subdivided into subgroups based on the activation protocol (subgroup A - ultrasonic activated and subgroup B - diode laser activated). The groups were Group 1 (control), Group 2 (3% NaOCl for 6 min; subgroup A - activated using a diode laser, subgroup B - ultrasonic activation), Group 3 (2% CHX for 6 min; subgroup A - activated using a diode laser, subgroup B - ultrasonic activation), and Group 4 (0.2% chitosan for 6 min; subgroup A - activated using a diode laser, subgroup B - ultrasonic activation. Confocal laser scanning microscopy was used to assess bacterial viability in situ. Data were analyzed by appropriate statistical analyses with P = 0.05. All experimental irrigation protocols destroyed the biofilm in the root canal lumen. Within the dentinal tubules, all groups had a significantly higher percentage of dead bacteria than the saline control (P < 0.05). There was no significant difference between CHX activated with ultrasonics, CHX activated with a diode laser, chitosan activated with ultrasonics and chitosan activated with diode laser groups (P > 0.05), whereas NaOCl ultra and NaOCl diode groups brought about more bacterial reduction than other groups (P < 0.05). The mean effectiveness and the bacterial kill ability were seen highest for the NaOCl activated with the ultrasonics group. There was no significant difference between diode laser activation and ultrasonic activation in CHX activated with ultrasonics, CHX activated with a diode laser, chitosan activated with ultrasonics and chitosan activated with diode laser groups (P > 0.05), but there was a significant difference between diode laser and ultrasonic activation in NaOCl group. Ultrasonic activation of the NaOCl was more effective than diode activation in reducing E. feacalis biofilms (P < 0.05). The use of NaOCl with the activation by ultrasonics caused the greatest reduction of E. faecalis. Ultrasonic activation was found superior to diode laser activation in dentinal tubule disinfection.

CBCT assessment of dentin thickness of lower incisors after shaping with NiTi instruments – in vivo study

Remaining root dentin thickness plays a key role in the longevity of endodontically treated teeth. Purpose: The aim of this study was to compare the root canal wall thickness in the danger zones of mandibular incisors before and after their instrumentation with two different NiTi rotary systems by means of CBCT. Methodology: Thirty lower incisors of patients aged 45 – 55 years underwent primary endodontic treatment with two NiTi files systems: ProTaper Universal and WaveOne Gold. The changes of the root canal thickness in the danger zones of the incisors were investigated by two CBCT scans – one at the beginning of the experiment and the other after the shaping of the root canals. Results: Shaping of the root canals of lower incisors with the two NiTi systems significantly decreased the mesio-distal root dentin thickness in all root canal levels when compared with the baseline values (p≤0.001). NiTi files from both experimental groups removed substantially more root dentin in the coronal portion of the root than in the apical (p&lt;0.05). The intergroup comparison between the two tested NiTi systems revealed no statistically significant difference in their performance at the three observation levels (p&gt;0.05). Conclusions: Both NiTi systems performed equally and removed dentin more aggressively in the coronal portion of the root. Further clinical experiments are necessary to find the minimally invasive endodontic systems for an optimal preservation of root dentin in the danger zones of mandibular inciso

Stereomicroscope Analysis of the Cleaning Capacity of an Abrasive-Expansive System in Oval Canals: A Laboratory Study

Background: The aim of this study was to evaluate, by means of a stereomicroscope, the influence on the removal of smear layer obtained by the XP-endo Finisher and Tornado Disinfection Kit systems during the final agitation of the irrigating solution, in conservative preparations. Materials and methods: Ten extracted human lower premolars were chemically-mechanically prepared with the ProDesign Logic 2 NiTi rotary system (25/.05) and 2.5% NaOCl. The same specimens were submitted to three different protocols of agitation of the irrigating solution: Conventional irrigation, XP-endo Finisher and Tornado Disinfection Kit. For this, a closed system was made, the roots were cleaved and three holes were made in each third of the root canal and filled with dentinal debris to take initial photos under a stereomicroscope. The amount of debris was rated using a 4-point scoring system. The data obtained were submitted to the Wilcoxon, Kruskal-Wallis and Dunn tests (p&lt;0.05). Results: In the analysis of the effectiveness of each protocol, it was possible to observe a statistically significant difference in the removal of debris in all thirds for all protocols (p&lt;0.05). Regarding the difference in score found before and after application of the protocol, a significant difference was observed between the apical and the middle third in the Tornado Disinfection Kit group (p&lt;0.05) and there was no difference between the same third for different groups (p&gt;0.05). Conclusion: Based on the methodology and the results presented, it was concluded that both evaluated protocols improved the cleaning of root canal recesses in all thirds, with no difference between them.

Comparative evaluation of cleaning efficiency of single file NiTi rotary system during root canal treatment procedure - A scanning electron microscope study.

Optimal biomechanical preparation, thorough irrigation, proper disinfection, and finally, well-sealed obturation is a must to attain definitive success in root canal procedure. Proper preparation of the root canal is all the more imperative to establish a hermetic apical seal with adequately placed filling materials. The present study was conducted for comparing the Cleaning Efficiency of F360 system and the WaveOne Gold (WOG) system of rotary NiTi instrumentation for a root canal. One hundred freshly extracted noncarious mandibular canines were obtained. Access cavity of standard size was made followed by the establishment of working length. Afterward, random division of all the specimens was done into two study groups: group A: the group in which F360 system was used for instrumentation and group B: the group in which the WOG system was used for instrumentation. Irrigations of all the specimens of both the study groups were done followed by root canal shaping by the instrument system of their respective study groups. Scanning electron microscope (SEM) was used for assessment after specimens were cut buccolingually. Debris score and residual smear layer score were used for assessment. Among group A specimens, the mean smear layer score at the coronal third, middle third, and apical third was 1.76, 2.39, and 2.65, respectively. Among group B specimens, the mean smear layer score at the coronal third, middle third, and apical third was 1.34, 1.59, and 1.92, respectively. While analyzing statistically, it was seen that the mean smear layer score was significantly higher among specimens of group A in comparison to group B. While analyzing statistically, it was seen that the mean debris score was significantly higher among specimens of group A in comparison to group B. The cleaning effectiveness of WOG instruments was significantly enhanced in comparison to F360 equipment.

The effect of NiTi rotary systems activated with different kinematics on canal transportation and centring ability. A concise review

One of the most crucial steps in endodontic therapy is canal preparation. The root canal should have a flare shape from apex to coronal areas, with the apical foramen maintained in its original relationship to the surrounding tissues and root surface. Anatomical complexity causes most endodontic problems. Ledges, zips, perforations, and root canal transportation are more probable in curved canals because all preparation procedures and instruments deviate the prepared canal away from its initial axis. The type of kinematics employed, including continuous rotation, reciprocation movement, and adaptive movement, as well as root canal anatomy and instrument design features, all have been found as factors that may affect canal transportation. There are controversial results concerning the influence of kinematic on canal transportation. These results may be attributed to a lack of standardisation in file characteristics such as taper, size, and cross-section. Studies started using the same system under continuous rotation and reciprocation movement or adaptive motion to overcome these issues. This article reviews the effects of movement types on canal transportation and centring ability when all other variables are the same.

The Effect of Different Irrigant Activation Methods on Postoperative Pain After Endodontic Retreatment

Aim: This study was designed to evaluate the effect of different irrigant activation methods on post operative pain after endodontic retreatment. Materials and Methods: seventy eight patients need non-surgical retreatment in mandibular first molar were involved in the study. The retreatment was performed in two visits, at first visit cases were randomly divided into three groups according to methods of irrigant activation after root canal retreatment with protaper next rotary ni-ti system. Group A (n=26) Root canals were irrigated using 2.6% sodium hypochlorite (NaOCl) with manual dynamic agitation using master cone Group B (n=26) Root canals were irrigated using 2.6% sodium hypochlorite (NaOCl) using ultrasonic machine (ultra-x) for 60 seconds. Group C (n=26) Root canals were irrigated using 2.6% sodium hypochlorite (NaOCl) with NaviTip (29-gauge 27 mm) with double side tip. At second visit after one week, obturation was performed using modified single cone technique ans access cavity was filled with coronal restoration. After two visits root canal treatment and a specific method of agitation, depending on each group, the patients were given a questionnaire on which the patient would mark the degree of pain in a scale from 0 to 10 at 6, 12, 24, 48 72 hrs and one week post-obturation. Data were statistically analyzed with a significance level of P ≤0.05. Results: At 6,12,24 hrs., there was significant difference between the groups in pain intensity where control group C (Navitip with side vented needle) showed more pain scores than in the intervention groups (Ultra X and manual dynamic agitation). On the other hand, at 48, 72 hours and 7 days post- operative, there was no statistically significant difference in pain among tested groups. Conclusion: Agitation of the irrigation is reliable safe to clinican and effective as final step irrigation protocol with successful management of postoperative pain in retreatment cases. The intensity of postoperative pain decreased with time regardless of final irrigation protocol used.

Mechanical Properties and Root Canal Shaping Ability of a Nickel-Titanium Rotary System for Minimally Invasive Endodontic Treatment: A Comparative In Vitro Study.

Selection of an appropriate nickel-titanium (NiTi) rotary system is important for minimally invasive endodontic treatment, which aims to preserve as much root canal dentin as possible. This study aimed to evaluate selected mechanical properties and the root canal shaping ability of TruNatomy (TRN), a NiTi rotary system designed for minimally invasive endodontic shaping, in comparison with existing instruments: HyFlex EDM (HEDM), ProTaper Next (PTN), and WaveOne Gold (WOG). Load values measured with a cantilever bending test were ranked as TRN &lt; HEDM &lt; WOG &lt; PTN (p &lt; 0.05). A dynamic cyclic fatigue test revealed that the number of cycles to fracture was ranked as HEDM &gt; WOG &gt; TRN &gt; PTN (p &lt; 0.05). Torque and vertical force generated during instrumentation of J-shaped artificial resin canals were measured using an automated instrumentation device connected to a torque and vertical force measuring system; TRN exhibited smaller torque and vertical force values in most comparisons with the other instruments. The canal centering ratio for TRN was smaller than or comparable to that for the other instruments except for WOG at the apex level. Under the present experimental conditions, TRN showed higher flexibility and lower torque and vertical force values than the other instruments.

Comparative Assessment of The Fracture Resistance of Teeth Instrumented by Two Different Nickel Titanium Rotary Systems

Aim: This study aimed to compare the fracture resistance exhibited by roots on instrumentation using two endodontic rotary systems: SANI S3 and EdgeEndo X7 rotary file systems. Materials and Methods: Sixty recently extracted human mandibular premolars comprising single root canals were selected in this study. All specimens were decoronated and mounted perpendicularly in self-cure acrylic resin blocks exposing 6 mm of the roots out of the acrylic resin blocks. The specimens were divided into two experimental groups, according to NiTi rotary systems used and one control group (n = 20). After instrumentation, the specimens of both experimental groups were then filled using master Gutta-percha cones size 35 (0.04 taper) and obturation was done using continuous wave compaction technique. The specimens were kept at 37 °C and 100% humidity for 2 weeks to allow complete setting of the sealer. Root fracture resistance was assessed using a universal testing machine (Instron) and the amount of load necessary for root fracture was recorded in Newtons (N). Statistics: Data were collected, tabulated and statistically analyzed using one-way ANOVA test and Tukey’s posthoc test. Results: Group C (control) exhibited the highest mean fracture force (357.13 ± 20.61) while group A (SANI S3) showed the lowest mean fracture force (192.60 ± 22.73). One-way ANOVA test showed statistically significant differences between tested groups. Regarding inter-group comparisons using Tukey’s test, there was a significant statistical difference between groups (A and B) and between groups (A and C). Furthermore, there was a statistically significant difference between groups (B and C). (P?0.05) Conclusion: 1-Root canal instrumentation with NiTi rotary files possessed a negative impact on roots and higher risks of root fractures compared to intact unprepared roots. 2-Design of NiTi files with improved cutting efficiency could diminish the risk of crack formation in root canal dentinal walls.

Comparative evaluation of canal transportation and centering ability of various Ni-Ti rotary systems in retreatment of curved root canals

Background: The aim of the present study was to evaluate the canal transportation and centering ability of ProTaper, HeroShaper and two Ni-Ti rotary systems developed for retreatment (ProTaperRetreatment and R-Endo). Materials and Methods: One hundred twenty mesial canals of mandibular molars with curvatures between 30-40 degrees and radii of curvatures between 4-9 mm were embedded in a modified muffle system. The teeth were randomly divided into 8 groups (n=15). The roots were sectioned horizontally at 3, 6 and 9 mm from the working length. Cross-sections were digitally photographed under standardized conditions. Half of the root canals were prepared with ProTaper and the rest with HeroShaper. Postoperative photographs were obtained. Root canals were obturated with the respective gutta-percha cones of the systems and AHPlus sealer. Following retreatment with four systems, photographs were assessed for the canal transportation in 8 directions, and centering ratio. Results: Initial shaping with ProTaper resulted in more significant transportation than HeroShaper (p&amp;lt;0.05). After retreatment, R-Endo yielded negative transportation values in the apical and mid-sections. In canals prepared with ProTaper, in the apical and coronal root sections ProTaperRetreatment, and in the mid-sections ProTaper revealed more acceptable re-shaping results. In the canals prepared with HeroShaper, after retreatment, transportation and centering ability were relatively efficient with HeroShaper in the apical and mid-sections; and with ProTaper in the coronal sections. Conclusion: All systems caused a certain amount of transportation and eccentricity. Protaper, ProtaperRetreatment and HeroShaper showed similar re-shaping performance with regard to the initial shaping procedure. However, R-Endo yielded insufficient root canal cleaning in the apical and mid-sections.

Comparative Evaluation Between Two NiTi Rotary Files Using CBCT

AIM: The aim of the study was to evaluate and compare the effects of WaveOne and Protaper Next on volume of dentin removed, centering ability and dentin thickness using CBCT on human mandibular molars. MATERIALS AND METHOD: Methodology: 50 recently extracted human mandibular molars were taken and divided into two groups i.e. Group 1- Pro taper next and Group -2 Wave One. The distal root was discarded and the mesiobuccal root canals were selected. Further the selected root canals were scanned to standardize the mesial root canal ranging from 15o to 45o followed by root canal preparation. Here CBCT a non invasive technique was used for assessment. The data extracted were tabulated and subjected to statistical analysis for pair wise comparison. RESULTS: It was seen that Protaper Next showed statistically significant centric ability where as dentin thickness at cervical, middle and apical level and showed no significant differences. Even mean of volume of removed dentin also showed no significant difference (p&gt;0.05) between the groups. CONCLUSION: The inventive method of NiTi rotary system is having better-quality shaping ability in curved canals that results more centered instruments and less canal errors.

Shaping ability of different NiTi rotary systems during the preparation of printed mandibular molars.

This study aimed to evaluate the shaping ability of XP-endo Shaper, TruNatomy and EdgeFile X3 during the preparation of resin-printed mandibular molar mesial root canals. Thirty-three resin-based mandibular mesial roots with two canals, obtained from extracted tooth cone-beam computed tomography (CBCT) image and printed on a three-dimensional (3D) printer, were divided into three experimental groups according to the different nickel-titanium (NiTi) systems used for root canal preparation. The specimens were scanned using CBCT imaging before and after root canal preparation. Then images were registered using a dedicated software and changes in the canal area, volume, untouched canal surface and the maximum and minimum dentine wall wear were calculated. The XP-endo Shaper instruments showed improved shaping ability with lower untouched root canal surface and better preservation of root canal anatomy during the preparation of resin-printed mandibular mesial root canals compared with TruNatomy and EdgeFile X3 systems.

Endodontic Rotary Files, What Should an Endodontist Know?

Clinicians should be aware of all the characteristics and capacities of the instruments that are possible to use when conducting a root canal treatment. The wide variety of nickel–titanium (Ni-Ti) rotary systems on the market and the lack of standardisation of this type of instrument makes the choice in each specific case difficult. Therefore, this review is intended to summarize the characteristics that should be taken into account when choosing one instrument over another. It will be essential to know characteristics, of alloy from which the instrument is made. Moreover, the geometry of the instrument will determine its behaviour, being the mass, the one that marks its resistance to a greater extent. The movement performed by the file is another of the fundamental keys to understand rotary instruments. In conclusion, when performing root canal treatment, the characteristics of the instrument and the tooth must be taken into account, and the operator’s own limitations should be known. This paper provides the key points to keep in mind when making this type of treatment.

The effectiveness of rotary and reciprocating techniques in curved root canals retreatment: a micro-CT analysis.

Introduction: Different NiTi rotary systems have been developed to improve efficiency and retreatment success rates. Aim: To evaluate the Protaper Universal retreatment system and WaveOne instrument in removing the filling material from curved canals during retreatment. Materials and Methods: Thirty mesial root canals of extracted human mandibular molar teeth were randomly allocated into 2 groups (n=15). In the PT group, retreatment was performed with ProTaper Universal Retreatment according to the manufacturer’s instructions. In the WO group, was used WaveOne Primary. ProTaper Universal F2 and F3 were used to achieve the apical diameter in both groups. The samples were scanned by micro-computed tomography pre and postoperatively to evaluate the filling material remaining. The percentage of material filling was compared between groups using Student’s T test and in the same group among thirds was compared using Kruskal-Wallis followed by Dunn’s post hoc test. Results: The filling material remaining was not statistically different between the groups (p≥0.05). The apical third presented a greater amount of remaining filling material when compared with the cervical third for both groups (p&lt;0.05). Conclusion: Rotary and reciprocating techniques can effectively, but not completely, remove the filling materials from the root canal system. The apical third presented a more significant amount of remaining filling material.

Comparison of cyclic fatigue resistance of three different rotary NiTi systems – An in-vitro study

Background: Nickel–titanium (NiTi) alloys created a revolution in the instrumentation of endodontics. However, they undergo unexpected fracture during the instrumentation of curved root canals due to cyclic fatigue. Hence, innumerable scientific and manufacturing researches are focused on fabricating NiTi rotary instruments with greater cutting efficiency and increased fatigue resistance. Aim: The aim of this study is to compare and evaluate the cyclic fatigue resistance of three different NiTi rotary file systems: Hyflex CM, Endostar E3, and Mani Silk. Materials and Methods: In this in-vitro study, 30 Hyflex CM (25/0.06), 30 Mani Silk (25/0.06), and 30 Endostar E3 (25/0.06) instruments were included. The static cyclic fatigue test was performed using a custom-made jig. The artificial canal was made of stainless-steel jig with an inner diameter of 1.5 mm, 45° angle of curvature, and radii of curvature of 5 mm. All the instruments were rotated according to the manufacturer's recommendations until failure occurred. The time taken to failure was recorded in seconds for each group using a digital chronometer. The data were analyzed statistically using the one-way analysis of variance, Post hoc test of Bonferroni was performed to identify pair-wise significance through SPSS 21.0 software (SPSS Inc, Chicago, IL, USA). The statistical significance was set at 5%. Results: Hyflex CM had the statistically highest fatigue resistance followed by Mani Silk and Endostar E3 (P &lt; 0.05). Conclusion: Within the limitations of the present in vitro study, it was found that cyclic fatigue resistance of Hyflex CM files was higher than the cyclic fatigue resistance of Mani Silk and Endostar E3 files.

A Comparative Examination of Cyclic Fatigue and Fragment Length of Three Different Types of Endodontic Rotary Files: An In Vitro Study

Introduction: Although of great scientific advancement in the properties and form, fracture of nickel-titanium (NiTi) files could occur during their use. The goal of this study was to compare resistance to cyclic fatigue of various rotary systems used in endodontics. Materials and Methods: Three types of NiTi rotary systems were tested – group A: One Curve, group B: Edge File, and group C: lusterdent NiTi files. In these files, taper is 0.06, and their diameter is 25 mm. Stainless steel block was used. This block contains artificial canals with a 60o curvature, 5 mm radius of curvature, 21 mm length, and 1.5 mm width. A number of cycles before fracture were obtained and measurement of fragment length was achieved. Statistical evaluation of readings was accomplished with ANOVA and Tukey post hoc test. Results: There were statistically significant differences between the three types of NiTi rotary systems considering the number of cycles before file fracture (P < 0.001). The differences between fracture lengths were not statistically significant (P = 0.15). Conclusion: The Edge File revealed the highest cyclic fatigue resistance.

Sealing ability of different obturating techniques in apically separated rotary files: An In Vitro study

Aim:Testing whether two sealant systems (cold laterally compacted gutta-percha and Obtura II) can be used with extraction across two apically separated rotational nickel-titanium files was the primary objective of this study (RACE and K3).Materials and Methods:Both the positive and negative control teeth were randomly distributed among 62 mandibular premolars to create two groups of 30 each. Following the RACE and K3 approaches, four subgroups were created from the roots. Subgroups A1, B1, and A2, B2 (n = 10 each) were formed in the apical thirds of the canal at 3 mm from the tip. There was no division of instruments between groups A3, B3, B4, and A4. When it came to obturation, the Obtura II method was used for A2, A4, B2, B4, and A1, A3. A dye extraction process was employed to determine whether the specimens had been obliterated. Analysis of variance (ANOVA), Student t test (two-tailed, independent), and Leven's test were used to ascertain the values for each of the study groups.Results:Group A1 had a substantially lower leakage rate than group B1. Groups A2, B2 and A3, B3 had no statistically significant differences. Group A4 had a substantially lower leakage rate than group B4.Conclusion:Even when the cracked NiTi rotary system was not present, Obtura II-obturated groups had less leakage than the lateral condensation approach.

Evaluation of Postoperative Pain Following Single-Visit Root Canal Treatment with Rotary and Reciprocal Ni-Ti File Systems in Children.

Background and Objectives: Postoperative pain is a common symptom of a flare-up after root canal treatments (RCTs). Insufficient instrumentation, extrusion of irrigation solutions and debris, and the existence of a periapical lesion are the factors affecting postoperative pain after root canal treatments. The aim of this study was to evaluate the postoperative pain and instrumentation time of the single-file reciprocating system and multiple-file Ni–Ti rotary system in children ages 9–12 years old. Materials and Methods: Our study was conducted on 51 permanent mandibular molars with the diagnosis of irreversible pulpitis. Patients were randomly assigned into two groups, and RCTs were completed with either the Reciproc Blue or Protaper NEXT file systems. Instrumentation time for each system was noted, and patients were given a pain scale that included a visual analog scale for 6, 24, 48, and 72 h after treatment. Postoperative pain scores and instrumentation times were analyzed statistically with a chi-square test and Student’s t-test. Results: There was no statistically significant difference in postoperative pain between the Reciproc Blue and Protaper NEXT systems at all time intervals. Instrumentation time was significantly shorter in the Reciproc Blue group in comparison with the Protaper NEXT group. Conclusions: Postoperative pain findings following RCT using single-file reciprocating systems were similar to the rotary system group. However, chair time in the reciprocating system group was significantly lower. This provided a comfortable and patient-friendly treatment approach for children, and could enhance their cooperation.

Shaping Ability of Three Ni-Ti Rotary Systems in Curved Root Canals of Extracted Teeth

Aims. The purpose of this study was to compare the effects of 3 different rotary Ni-Ti instruments used to prepare curved root canals on the root canal curvature by using Digora system. Methods. Mesiobuccal canals of 30 mandibular first molars with curvature between 20-40 degrees were divided into 3 equal groups according to Ni-Ti rotary system need for root canal preparation: Alpha, RaCe and ProTaper system. Root canal curvatures from both buccal and proximal view were measured before and after instrumentation by using Digora system and image analysis software according Schneider's technique. Results. The result indicated that ProTaper system showed significantly greater decrease in curvature in the mesio-distal view and in the bucco-lingual view (p&lt;.05). Conclusion. The current study concluded that the rotary Ni-Ti RaCe system better maintained the original root canal curvature than the rotary Ni-Ti Alpha System and ProTaper Universal Systems. It may be better to use the rotary Ni-Ti RaCe system to prepared curved canal in order to maintained the original root canal curvature.