Dentinal Defects Research Articles

Evaluation of Effect of Hyflex EDM on Root Dentin during Root Canal Preparation-A Stereomicroscopic Study

<p><strong>Background:</strong> Root canal preparations done using many rotary endodontic instruments results in formation of root dentin defects because of the stress induced by the instruments within the root canal during cleaning and shaping, thereby worsening the long term prognosis of the root canal treated teeth. Many rotary instruments are been globally studied for the purpose of generating a correct instrument for root canal preparation.</p><p><strong>Objective:</strong> This study was done to evaluate the effect of HyFlex EDM, which is a new rotary system on root dentin during root canal preparation.</p><p><strong>Materials and methods:</strong> Fourteen single rooted premolars were selected and divided into two groups, Group 1-Protaper Universal and Group 2-HyFlex EDM. All the specimens were decoronated. Roots of each specimen were sectioned at 3mm, 6mm and 9mm and were then viewed under stereomicroscope for dentinal defects. t-test was done for the statistical analysis and level of significance was set at p=0.05.</p><p><strong>Results:</strong> Protaper Universal showed highest percentage of defect than HyFlex EDM.</p><p><strong>Conclusion:</strong> HyFlex EDM showed lowest percentage of defects in root dentin. Thus, HyFlex EDM is more efficient in root canal preparation than that of Protaper Universal thereby preventing dentinal defects or microcracks leading to root fractures.</p>

Evaluation of Effect of Hyflex EDM on Root Dentin during Root Canal Preparation-A Stereomicroscopic Study

Background: Root canal preparations done using many rotary endodontic instruments results in formation of root dentin defects because of the stress induced by the instruments within the root canal during cleaning and shaping, thereby worsening the long term prognosis of the root canal treated teeth. Many rotary instruments are been globally studied for the purpose of generating a correct instrument for root canal preparation. Objective: This study was done to evaluate the effect of HyFlex EDM, which is a new rotary system on root dentin during root canal preparation. Materials and methods: Fourteen single rooted premolars were selected and divided into two groups, Group 1-Protaper Universal and Group 2-HyFlex EDM. All the specimens were decoronated. Roots of each specimen were sectioned at 3mm, 6mm and 9mm and were then viewed under stereomicroscope for dentinal defects. t-test was done for the statistical analysis and level of significance was set at p=0.05. Results: Protaper Universal showed highest percentage of defect than HyFlex EDM. Conclusion: HyFlex EDM showed lowest percentage of defects in root dentin. Thus, HyFlex EDM is more efficient in root canal preparation than that of Protaper Universal thereby preventing dentinal defects or microcracks leading to root fractures.

Occurence of dentinal defects after root canal preparation with R-phase, M-Wire and Gold Wire instruments: a micro-CT analysis

BackgroundThis study aims to evaluate the frequency of dentinal defects after root canal preparation with the ProTaper NEXT, K3XF and WaveOne GOLD systems using microcomputed tomography.MethodsSixty permanent mandibular incisors with a single canal were selected. Inspection of the teeth was performed under a stereomicroscope (15x) to observe the presence of pre-existing cracks and fractures lines. Samples were divided into three experimental groups (n = 20): ProTaper NEXT (PTN), K3XF (K3XF) and WaveOne GOLD (WOG). Specimens were scanned through high-resolution microcomputed tomography before and after the preparation of the root canal. Subsequently, all the axial images were examined by two different methods to find possible dentinal defects. Furthermore, an analysis of each millimeter of ten apical millimeters was also performed. The absence or presence of dentinal defects was screened by 3 pre-calibrated blinded examiners.ResultsAfter analysing all 45,720 slices, dentinal defects were observed in 48,33% (22096 slices). PTN, K3XF and WOG groups represented 11,11% (5079 slices), 17,22% (7873 slices) and 20% (n = 9144) of the cross-sectional images, respectively. At 10 apical millimeters (600 slices), 33,33% (200 slices) presented some dentinal defects, representing 7,22% (43 slices), 13,33% (80 slices) and 12,77% (77 slices) of the cross-sectional images in the PTN, K3XF and WOG groups, respectively. All the dentinal defects presented in the postoperative images existed in the images prior to instrumentation.ConclusionsThere was no correlation between the preparation of a root canal using the PTN, K3XF and WOG systems and the formation of new dentinal defects.

Ancient Vitamin D Deficiency: Long-Term Trends

Vitamin D deficiency is now widely recognized as one of the most common health conditions in the world, with important consequences for overall health. Levels of deficiency appear to be rising, but the extent to which past humans were affected by vitamin D deficiency and the roles of this hormone in past human health are currently unknown. The discovery that mineralization defects in tooth dentin reflect periods of deficiency and are preserved in our earliest ancestors offers a unique opportunity to provide information on past social and cultural organization and, with further work, to contribute to ongoing debates on change in skin pigmentation. Here we show that humans from some of the earliest Middle Eastern and European communities were affected by deficiency, but levels and severity appear to have increased notably through time. On a simple comparative scale, severity of deficiency was four times as high in Greek communities in 1948 CE as in early farming communities from ca. 3000 BCE; some individuals in the later periods would have had rickets. Research using interglobular dentin in humans and nonhuman primates has the potential to fill in many important gaps in understanding past and present aspects of vitamin D deficiency.

Effect of ProTaper Gold, Self-Adjusting File, and XP-endo Shaper Instruments on Dentinal Microcrack Formation: A Micro–computed Tomographic Study

IntroductionThe aim of the present study was to evaluate the frequency of dentinal microcracks observed after root canal preparation with ProTaper Universal (PTU; Dentsply Tulsa Dental Specialties, Tulsa, OK), ProTaper Gold (PTG; Dentsply Tulsa Dental Specialties), Self-Adjusting File (SAF; ReDent Nova, Ra'anana, Israel), and XP-endo Shaper (XP; FKG Dentaire, La Chaux-de-Fonds, Switzerland) instruments using micro–computed tomographic (CT) analysis. MethodsForty extracted human mandibular premolars having single-canal and straight root were randomly assigned to 4 experimental groups (n = 10) according to the different nickel-titanium systems used for root canal preparation: PTU, PTG, SAF, and XP. In the SAF and XP groups, the canals were first prepared with a K-file until #25 at the working length, and then the SAF or XP files were used. The specimens were scanned using high-resolution micro–computed tomographic imaging before and after root canal preparation. Afterward, preoperative and postoperative cross-sectional images of the teeth were screened to identify the presence of dentinal defects. For each group, the number of microcracks was determined as a percentage rate. The McNemar test was used to determine significant differences before and after instrumentation. The level of significance was set at P ≤ .05. ResultsThe PTU system significantly increased the percentage rate of microcracks compared with preoperative specimens (P < .05). No new dentinal microcracks were observed in the PTG, SAF, or XP groups. ConclusionsRoot canal preparations with the PTG, SAF, and XP systems did not induce the formation of new dentinal microcracks on straight root canals of mandibular premolars.

Evaluation of dentinal defects during root canal preparation using thermomechanically processed nickel-titanium files.

Objective:The aim of this study was to compare the incidence of root cracks after root canal instrumentation with thermomechanically processed nickel-titanium (Ni-Ti) files with different instrumentation kinematics.Materials and Methods:A total of 150 extracted mandibular premolars with mature apices and straight root canals were divided into five groups and used in this study. In Group 1, 30 teeth were prepared using hand K-files and assigned to control group, Group 2 was instrumented using K3XF Rotary files (SybronEndo, Glendora, CA, USA) with continuous rotary motion. The teeth in Group 3 were instrumented by ProTaper Next (Dentsply Maillefer, Ballaigues, Switzerland) rotary files which make asymmetric rotary motion, In Group 4, teeth were instrumented by RECIPROC (VDW, Munich, Germany) with reciprocation motion and in Group 5, teeth were instrumented by Twisted File (TF) Adaptive (SybronEndo, Orange, CA, USA) files that use combination of continuous rotation and reciprocation motion (n = 30/per group). All the roots were horizontally sectioned 3, 6, and 9 mm from the apex with a low speed saw under water cooling. Then, the slices were examined through a stereomicroscope to determine the presence of dentinal microcracks.Results:For the apical (3-mm) and coronal (9-mm) sections, the ProTaper Next and TF Adaptive produced significantly more cracks than the hand files, RECIPROC, and K3XF (P < 0.05). There was no significant difference between the experimental groups and control group at the 6-mm level (P > 0.05).Conclusions:Within the limitations of this in vitro study, all thermal-treated Ni-Ti instruments and hand files caused microcracks in root canal dentin.

Influência da solução irrigadora na formação de defeitos dentinários após preparo com Sistema Reciproc®

Resumo Introdução Diferentes concentrações de hipoclorito de sódio (NaOCl) estão disponíveis para serem utilizadas durante o preparo biomecânico dos canais radiculares pelos instrumentos reciprocantes. Devido à rapidez com que o canal é instrumentado nessa nova cinemática reciprocante, concentrações mais elevadas de NaOCl são recomendadas. Assim, torna-se oportuna uma investigação para avaliar se a solução irrigadora NaOCl potencializa a possibilidade de formação de defeitos dentinários provocados pelo sistema Reciproc. Objetivo Analisar a influência da solução irrigadora hipoclorito de sódio na formação de defeitos dentinários provocados pelo sistema de instrumentação Reciproc®. Material e método Foram utilizados 60 primeiros pré-molares superiores extraídos, sendo estes distribuídos em dois grupos: (G1) NaOCl 5,25% (n=30) e (G2-controle) água destilada (n=30), nos quais somente o conduto vestibular foi instrumentado com o Sistema Reciproc® e irrigado com as soluções citadas. Todas as coroas dos dentes foram cortadas perpendicularmente ao seu longo eixo e as raízes foram incluídas em alvéolo e ligamento periodontal simulados. Os condutos palatinos não foram instrumentados nem irrigados, pois estes serviram como controle para o próprio espécime. Ao término da instrumentação, as raízes foram seccionadas em 2, 4, 6 e 8 mm a partir do forame apical, e levadas ao microscópio estereoscópico para se avaliar e registrar a formação de defeitos dentinários. Resultado Foram encontrados defeitos dentinários no Grupo controle (G2) e no grupo hipoclorito de sódio 5,25% (G1), porém não houve diferença estatisticamente significante entre esses grupos (p&gt;0,05). Conclusão O hipoclorito de sódio não desencadeou alterações de defeitos dentinários quando utilizado em associação com a instrumentação pelo Sistema Reciproc®.

Incidence of Dentinal Defects on the External Apical Root Surface after Instrumentation with WaveOne Reciprocating Files at Different Working Lengths

IntroductionThe aim of this in vitro study was to identify the formation of dentinal defects on the external apical root surface of teeth instrumented at different working lengths by using WaveOne reciprocating files. MethodsSixty human single-rooted mandibular premolars were divided into 3 groups (n = 20) according to the file used for instrumentation: WaveOne Small (WOS), premolars presenting mechanical resistance to the penetration of #10 K-file 1 mm short of the apical foramen; WaveOne Primary (WOP), this limit easily reached with #10 K-file; and WaveOne Large (WOL), this limit easily reached with #20 K-file or higher. A closed system and a muffle were created to allow alternating sessions of root canal instrumentation and image acquisition. The teeth were further divided according to 3 different working lengths: 1 mm short of the apical foramen, flush with the apical foramen, and 1 mm beyond the apical foramen. Micrographs of the external apical root surface of each specimen at baseline and after instrumentation up to each working length were examined for the presence of dentinal defects. Inter-examiner agreement was evaluated by using Pearson correlation test, and the Kruskal-Wallis test was used to analyze intragroup and intergroup differences (P < .05). ResultsInter-examiner agreement was high in all experimental groups (r = 1.0000, r = 0.8885, and r = 0.7867 for WOS, WOP, and WOL, respectively). There was no significant difference in the number of teeth with dentinal defects in the intergroup (P = .8119) or intragroup analyses (P = .9309, .8648, and .4772 for WOS, WOP, and WOL, respectively). ConclusionsInstrumentation with different WaveOne files up to different working lengths was not associated with the formation of dentinal defects.

Micro–computed Tomography Assessment of Dentinal Micro-cracks after Root Canal Preparation with TRUShape and Self-adjusting File Systems

IntroductionThe aim of the present study was to evaluate the percentage frequency of dentinal micro-cracks observed after root canal preparation with TRUShape and Self-Adjusting File (SAF) systems by means of micro–computed tomography imaging analysis. A conventional full-sequence rotary system (BioRace) and a single-file reciprocation system (Reciproc) were used as reference techniques for comparison because of their known assertive cutting efficiency. MethodsForty anatomically matched mandibular incisors were selected, scanned at a resolution of 14.25 μm, and assigned to 4 experimental groups (n = 10), according to the preparation protocol: TRUShape, SAF, BioRace, and Reciproc systems. After the experimental procedures, the specimens were scanned again, and the registered preoperative and postoperative cross-section images of the roots (n = 70,030) were screened to identify the presence of dentinal micro-cracks. ResultsOverall, dentinal defects were observed in 28,790 cross-section images (41.11%). In the TRUShape, SAF, BioRace, and Reciproc groups, dentinal micro-cracks were visualized in 56.47% (n = 9842), 42.38% (n = 7450), 32.90% (n = 5826), and 32.77% (n = 5672) of the slices, respectively. All dentinal defects observed in the postoperative data sets were already present in the corresponding preoperative images. ConclusionsNone of the preparation systems induced the formation of new dentinal micro-cracks.

In vivo remineralization of dentin using an agarose hydrogel biomimetic mineralization system

A novel agarose hydrogel biomimetic mineralization system loaded with calcium and phosphate was used to remineralize dentin and induce the oriented densely parallel packed HA layer on defective dentin surface in vivo in a rabbit model. Firstly, the enamel of the labial surface of rabbits’ incisor was removed and the dentin was exposed to oral environment. Secondly, the hydrogel biomimetic mineralization system was applied to the exposed dentin surface by using a custom tray. Finally, the teeth were extracted and evaluated by scanning electron microscopy, X-ray diffraction, and nanoindentation test after a certain time of mineralization intervals. The regenerated tissue on the dentin surface was composed of highly organised HA crystals. Densely packed along the c axis, these newly precipitated HA crystals were perpendicular to the underlying dental surface with a tight bond. The demineralized dentin was remineralized and dentinal tubules were occluded by the grown HA crystals. The nanohardness and elastic modulus of the regenerated tissue were similar to natural dentin. The results indicated a potential clinical use for repairing dentin-exposed related diseases, such as erosion, wear, and dentin hypersensitivity.

Phenotype and genotype analyses in seven families with dentinogenesis imperfecta or dentin dysplasia.

Hereditary dentin defects can be categorised into two classes according to their clinical manifestations: dentinogenesis imperfecta (DGI), which includes three types (DGI-I, DGI-II and DGI-III), and dentin dysplasia (DD), which includes two types (DD-I and DD-II). This study investigated the phenotypic characteristics and genetic causes of hereditary dentin defects in seven Chinese families. Seven families affected with DGI-II, DGI-III or DD-II were enrolled. Clinical examinations were performed to determine the phenotypic characteristics, and DNA samples were collected for Sanger sequencing. Clinical diagnoses revealed DGI-II in five families, DGI-III in one family and DD-II in one family. Variants of the dentin sialophosphoprotein (DSPP) gene were found in six of the seven families. Of these, c.52G>T was identified in two families. Each of the remaining four families had a different variant: c.2684delG, c.52-2A>G, c.1874-1877delACAG and c.3509-3521del13bp; the last three variants were novel. This is the first study to analyse all three important types of hereditary dentin defect and include comprehensive genetic analyses of both dentin sialoprotein and dentin phosphoprotein in Chinese families. This study expands the spectrum of DSPP variants, highlighting their associated phenotypic continuum.

Effect of different nickel-titanium rotary files on dentinal crack formation during retreatment procedure.

Background. The aim of this study was to compare the dentinal defects caused by Reciproc, TF Adaptive and ProTaper Next NiTi rotary file systems during the retreatment procedure. Methods. A total of 150 mandibular incisors with straight and single root canals were included in the present study. All the root canals were prepared up to an apical diameter 0.40 mm using stainless steel files. Thirty teeth were randomly stored as the negative control group. A total of 120 specimens were obturated with gutta-percha and AH Plus sealer using vertical compaction technique. Thirty specimens with root canal filling were randomly separated for the only-filled group. Then the teeth were randomly divided into 3 groups; Reciproc, TF Adaptive and ProTaper Next. The retreatment procedure was performed with these NiTi files. Then 150 specimens were cut perpendicular to tooth axis at 3-, 6-, and 9-mm distances from the apex, and examined to determine the presence of any cracks at ×25 under a stereomicroscope. Chi-squared test was used at 5% significance level. Results. All the tested NiTi file systems were found to cause significantly more dentinal defects compared to unprepared and only-filled groups (P<0.05). No statistically significant differences were found between the groups in terms of dentinal defects (P>0.05). No correlation was found between the slice levels and the dentinal defect distribution (P>0.05). Conclusion. Within the limitations of present study, all the tested NiTi file systems were found to cause significantly more dentinal defects compared to unprepared and only-filled groups.

Comparison of Dentinal Defects induced by Hand Files, Multiple, and Single Rotary Files: A Stereomicroscopic Study

ABSTRACT Aim This study was carried out to compare the dentinal defects induced by single rotary file system, multiple rotary file system, and hand files. Materials and methods Sixty single-rooted premolars were selected based on predetermined criteria. They were divided into three groups: Group I (hand K files), group II (Hero Shaper), and group III (One Shape). Biomechanical preparation was carried out as per the manufacturer's instructions. Each specimen was sectioned horizontally and divided into apical, middle, and coronal sections. These sections were visualized under stereomicroscope to evaluate the dentinal defects using predetermined criteria. Results Roots prepared with Hero Shaper showed more number of defects than One Shape, whereas in roots prepared with hand files lowest percentage of dentinal defects were present. There was statistically significant difference between the Hero Shaper group and the One Shape group (p &lt; 0.05). Conclusion All rotary files induce defects in root dentin, whereas the hand instruments induce minimal defects. Clinical significance With single rotary file system, preparation time is reduced and it is easier for patients to accept the treatment. Moreover, the potential of root fracture is reduced. How to cite this article Jain A, Bhadoria K, Choudhary B, Patidar N. Comparison of Dentinal Defects induced by Hand Files, Multiple, and Single Rotary Files: A Stereomicroscopic Study. World J Dent 2017;8(1):45-48.

Light-emitting diode assessment of dentinal defects: the role of presumed extraction forces.

ObjectivesThe evaluation of iatrogenic dentinal defects in extracted teeth may be influenced by extraction forces and prolonged dry times. The purpose of this study was to compare the presence of dentinal defects in freshly extracted, periodontally compromised teeth with those in a group of teeth with uncontrolled extraction forces and storage time.Materials and MethodsThe experimental group consisted of eighteen roots obtained from teeth extracted due to periodontal reasons with class II or III mobility. They were kept in saline and sectioned within 1 hour following extraction. The control group consisted of matched root types obtained from an anonymous tooth collection, consistent with previous dentinal defect studies. The slices were obtained at 3, 6, and 9 mm from the apex. The imaging process exposed all specimens to no more than 60 seconds of dry time. The × 12.8 magnification was used for the 9 mm slices and × 19.2 magnification for the 3 mm and 6 mm slices under light-emitting diode (LED) transillumination. The root canal spaces and periodontal tissues were masked to minimize extraneous factors that might influence the evaluators. Chi-square test was used for statistical analysis.ResultsDentinal defects were detected in 17% of the experimental group teeth, compared to 61% of control teeth (p = 0.015).ConclusionsLED transillumination assessment of freshly extracted roots with class II or III mobility showed smaller number of dentinal defects than roots with uncontrolled storage time and extraction forces. The use of freshly extracted roots with mobility should be considered for future dental defect assessment studies.

Evaluation of Dentin Defect Formation during Retreatment with Hand and Rotary Instruments: A Micro-CT Study.

The purpose of this study was to compare the incidence and longitudinal propagation of dentin defects after gutta-percha removal with hand and rotary instruments using microcomputed tomography. Twenty mandibular incisors were prepared using the balanced-force technique and scanned in a 19.9 μm resolution. Following filling with the lateral compaction technique, gutta-percha was removed with ProTaper Universal Retreatment (PTUR) or hand instruments. After rescanning, a total of 24,120 cross-sectional images were analyzed. The numbers, types, and longitudinal length changes of defects were recorded. Defects were observed in 36.90% of the cross sections. A total of 73 defects were comprised of 87.67% craze lines, 2.73% partial cracks, and 9.58% fractures. No significant difference in terms of new defect formation was detected between the retreatment groups. The apical and middle portions of the roots had more dentin defects than the coronal portions. Defects in three roots of the PTUR instrument group increased in length. Under the conditions of this in vitro study, gutta-percha removal seemed to not increase the incidence of dentin defect formation, but the longitudinal defect propagation finding suggests possible cumulative dentinal damage due to additional endodontic procedures. Hand and rotary instrumentation techniques caused similar dentin defect formation during root canal retreatment.

Comparative evaluation of dentinal defects induced by hand files, hyflex, protaper next and one shape during canal preparation: A stereomicroscopic study

Aim: This study aims to evaluate and compare the incidence of dentinal defects induced by Hand Files, HyFlex CM, ProTaper Next (PTN), and One Shape during canal preparation. Materials and Methods: One hundred and fifty extracted mandibular premolar teeth with single root canal were selected. Specimens were then divided into five groups with thirty specimens each. Group I: Specimens were prepared with hand instruments. Group II: Specimens were prepared with HyFlex CM rotary files (Coltene) using a crown-down technique according to the manufacturer's instructions. Group III: Specimens were prepared with PTN rotary files (Dentsply) using a crown-down technique according to the manufacturer's instructions. Group IV: Specimens were prepared with One Shape Single file rotary system (MicroMega) using a crown-down technique according to the manufacturer's instructions. Group V: Specimens were used as a control and left unprepared. All roots were cut horizontally at 3, 6, and 9 mm from the apex. Sections were then viewed under stereomicroscope and dentinal defects were registered as “no defect,” “fracture,” and “other defects.” Statistical Analysis: Results of the study were subjected to Chi-square test. Results: Results were expressed as the number and percentage of defected, partially defected and roots with no defects in each groups. Conclusion: Hand files and One Shape file system caused less root defects compared to PTN and HyFlex file systems.

Incidence of Dentinal Defects and Vertical Root Fractures after Endodontic Retreatment and Mechanical Cycling.

Introduction:The aim of this study was to evaluate the incidence of dentinal defects and vertical root fractures (VRFs) after endodontic retreatment and mechanical cycling (MC). Methods and Materials:Two hundred mandibular premolars were selected. Forty teeth were left unprepared (control group). The remaining 160 root canals were prepared with ProTaper instruments and filled by using two different techniques [eighty with lateral compaction (LC) and eighty with single-cone (SC)]. Forty canals from each group (LC and SC) received no further treatment. The remaining eighty teeth were divided into two groups (LCR and SCR) (n=40) in order to undergo the removal of the root filling, re-preparation and refilling with lateral compaction and single-cone, respectively. All of the teeth were subjected to MC (1000000 cycles, 130 N, 2.2 Hz and 37°C). The roots were sectioned at 3, 6 and 9 mm from the apex and observed under 20× magnification. The defects were classified as: no defect, VRF and other defects. Statistical analysis was performed using the Fisher’s Exact test and the Chi-Squared tests (α=0.05). Results:MC alone did not promote any other defects or VRFs. Experimental groups presented higher dentinal defects than the control group (P=0.021). Retreatment groups did not present a higher amount of dentinal defects than the groups that were subjected to the first treatment (P>0.05). Conclusion:Endodontic treatment and retreatment, regardless of the filling technique and MC, did not influence the occurrence of dentinal defects or VRFs in the human premolars.

Incidence of dentinal defects during root canal preparation with hand files using different irrigants: An in vitro study.

Introduction:The purpose of this in vitro study was to compare the incidence of dentinal defects during root canal preparation with hand files using different irrigants.Materials and Methods:A total of 120 extracted mandibular incisors were randomly divided into onecontrol group and five experimental groups (n = 20) depending on the irrigant used. Biomechanical preparation was not done in control group. Teeth in experimental groups were prepared with hand K-files to a master apical file #35 with 1-mm increments step-back up to #50. In Group 2, saline was used as an irrigant. In Groups 3, 4, 5, and 6, 3% sodium hypochlorite (NaOCL), SmearClear, 17% ethylenediaminetetraacetic acid (EDTA), and 2% chlorhexidine (CHX), respectively, were used as an irrigant. Specimens were sectioned perpendicular to the long axis at 3, 6, and 9 mm from the apex. Sections were observed under a digital stereomicroscope at 30× magnification. Two-tailed t-test was used for statistical analysis.Results:There was a statistically significant difference between the six groups. Group 5 (17% EDTA) had the highest number of dentinal defects, followed by Group 3 (3% NaOCl), Group 4 (SmearClear), and Group 6 (2% CHX).Conclusions:17% EDTA causes more dentinal defects as compared to 3% NaOCl, SmearClear, 2% CHX, and saline.

Dentinal Defects in Endodontically Treated Teeth using NiTi Rotary vs Reciprocating Endodontic Instruments- A Systematic Review

Dentinal Defects in Endodontically Treated Teeth using NiTi Rotary vs Reciprocating Endodontic Instruments- A Systematic Review

Comparison of the Effects of Three Different Nickel–titanium Rotary Instruments on the Fracture Resistance of Obturated Roots: An in vitro Study

ABSTRACTAimThe aim of the article is to compare the effects of three different nickel–titanium (NiTi) rotary instruments on the fracture resistance of obturated roots.Materials and methodsA total of 100 permanent mandibular premolars were randomly divided into four groups of 25 teeth each and biomechanical preparation was done: group I: stainless steel K-hand files (HFs), group II: ProTaper NiTi instruments (PT), group III: HyFlex CM NiTi instruments (HCM), and group IV: K3XF NiTi instruments. Following root canal preparation, the canals were obturated using lateral condensation. A light body silicone impression material was used to simulate the periodontal ligament (PDL). Fracture resistance was tested in an Instron testing machine.Statistical analysisData were analyzed with Kruskal–Wallis test.ResultsThere was no difference in significance (p &lt; 0.05) among the different groups tested with respect to their fracture resistances.ConclusionThe present study concluded that rotary instrumentation could result in an increased chance for dentinal defects as compared with hand instrumentation. Greater taper rotary NiTi instruments do not increase the fracture susceptibility of roots, which in turn depends on various factors other than instrumentation alone.Clinical significanceGreater taper achieved by rotary NiTi files during canal preparation facilitates efficient irrigation and complete debridement. Root fracture might occur as a result of microcracks or craze lines that propagate with repeated stress application by occlusal forces and also during canal preparation. Based on the results obtained, it can be decided whether the use of the newer rotary NiTi system contributes to endodontic success and long-term survival of endodontically treated teeth.How to cite this articleShaikh SAH, Shenoy VU, Sumanthini MV, Pawar RB. Comparison of the Effects of Three Different Nickel–titanium Rotary Instruments on the Fracture Resistance of Obturated Roots: Anin vitroStudy. J Contemp Dent 2017;7(2):86-90.