Comparison of incidence of dentinal defects after root canal preparation with continuous rotation and reciprocating instrumentation

Comparative evaluation of incidence of dentinal defects after root canal preparation using three different endodontic retreatment systems - An in vitro study

Context

Safe and efficient removal of all root filling materials from the root canal system without compromising radicular dentin structure is essential for optimal nonsurgical retreatment.

Aims

The aim of this study was to evaluate and compare the incidence of dentinal defects caused during root canal filling removal using conventional, rotary, and reciprocating retreatment file systems.

Settings and Design

A detailed protocol explaining purpose and procedures of the study was submitted to the Institutional Ethics Committee and ethical clearance obtained.

Subjects and Methods

Sixty human maxillary permanent central incisors were collected and decoronated to 12-mm standardized length. The canals prepared up to a master apical file size F3 with Protaper hand files, obturated using AH plus sealer, examined under the stereomicroscope (×40 magnification): Group I: Control (n = 15), Group II: Conventional (n = 15), Group III: Protaper Universal Retreatment Files (n = 15), and Group IV: Reciproc Blue (n = 15). After instrumentation, teeth were sectioned at 3, 6, and 9 mm from the apex to evaluate the presence of dentinal defects under the stereomicroscope.

Statistical Analysis Used

Statistics were performed using the SPSS, version, 25 (SPSS Inc., Chicago, IL, USA). Initially, normality test was done using the Shapiro-Wilk test and data were not normally distributed followed by Kruskal-Wallis test. P < 0.05 is considered statistically significant.

Results

Maximum percentage increase in dentinal defects was observed in Protaper Universal Retreatment Files followed by Conventional method and Reciproc Blue.

Conclusions

Significantly Reciproc Blue reduced the incidence of dentinal defects after root canal preparation.

The state of the art and future trends of root canal files from the perspective of patent analysis: a study design

The goal of this review is to present a detailed and comprehensive description of the published work from the past decade regarding methods of improved material, geometric design, and additional functions in root canal files. The main improved methods of files and the most common technologies were further addressed, underlining their advantages and main limitations. Online databases (the Derwent Innovations Index) were consulted on this topic. Published work from 2010 to 2022 was collected and analyzed the relevant papers were chosen for inclusion in this review. The patent map classified the latest phase of the root canal files based on the analysis of the number of patents. The performance of the root canal files, such as materials. Directly affects the quality of the root canal therapy. We provided a thorough review of advances in the field of root canal files. In particular, three categories of improved methods were examined and compared, including material-based methods, geometry-based methods, and those based on additional functions. To understand this state of the art of different improved methods of root canal files, we conducted a literature analysis and a series of comparisons between different methods. The features and limitations of each method of root canal files were further discussed. Finally, we identified promising research directions in advancing the methods for the improved performance of root canal files. There is no perfect technology for all material/geometric design/additional functions, capable alone of fulfilling all the specificity and necessities of every patient. Although it is very promising, the material of the files remains understudied, and further work is required to make material science a pervasive technology in root canal therapy, and contribute to endodontic and periapical diseases by assisting in the subsequent development of root canal files.

ÇEŞİTLİ YENİ EĞE SİSTEMLERİNİN NEDEN OLDUĞU DENTİN ÇATLAKLARININ MİKRO BİLGİSAYARLI TOMOGRAFİK DEĞERLENDİRİLMESİ

Amaç: Bu çalışmanın amacı, ProTaper Gold (PTG), WaveOne Gold (WOG), OneShape Yeni Nesil (OSNG), K3XF nikel-titanyum (NiTi) enstrümantasyon sistemlerinin kullanımından sonra gözlenen dentin mikro çatlaklarının insidansını değerlendirmektir. . Gereç ve Yöntem: Altmış adet çekilmiş insan mandibular birinci molar dişi rastgele dört gruba ayrıldı (n = 15). Kök kanalları PTG, WOG, OSNG ve K3XF sistemleri ile enstrümante edildi. Köklerin kesit görüntüleri, dentin çatlaklarının varlığını tespit etmek için hazırlıktan önce ve sonra yüksek çözünürlüklü mikro bilgisayarlı tomografi görüntüleme kullanılarak tarandı. Bulgular: PTG ve WOG sistemleri arasında istatistiksel olarak anlamlı bir fark olmamasına rağmen, WOG tüm gruplar arasında daha az mikro-çatlamaya neden oldu. K3XF, OSNG'den istatistiksel olarak daha az çatlak gösterdi. K3XF ve OSNG sistemleri, her iki Gold sisteminden istatistiksel olarak daha fazla dentin mikro çatlaklarına neden oldu. WOG ve PTG sistemleri, bu çalışmada değerlendirilen sistemler arasında daha az mikro çatlak oluşumuna neden olmuştur. Kanal tedavileri sırasında mikro çatlakları en aza indirmek için her iki Gold sistemi de daha güvenli olarak tercih edilebilir. Sonuçlar: Kullanılan tüm sistemler farklı derecelerde çatlak oluşumlarına neden olmuştur. Ayrıca WOG ve PTG sistemleri, OSNG ve K3XF sistemlerine göre dentin çatlakları oluşturma konusunda üstün özellikler göstermiştir.

Stereomicroscopic Evaluation of Microcrack Formation in Dentin by ProTaper Next, Revo S, and WaveOne Gold File System

Background

During the biomechanical preparation of the root canal by rotary file systems, stress is generated within the canal, which leads to dentinal microcrack formation. Such defects are evaluated only under the microscope.

Aim

The present study aimed to evaluate dentinal microcrack formation after instrumentation with ProTaper Next (M-wire), Revo S (conventional NiTi), and WaveOne Gold (Gold-wire) file systems under the stereomicroscope.

Materials and Methods

Forty single-rooted teeth free from any defect were selected and divided into four groups (Control, PTN, RS, and WOG). Experimental groups were instrumented with file system used in the study, and the control group were left unprepared. Samples were further decoronated and sectioned at 3 mm, 6 mm, and 9 mm from the apex perpendicular to the long axis and examined under a stereomicroscope at ×25 for different types of microcracks (no fracture, complete fracture, partial fracture, and other fracture).

Statistical Analysis Used

Data analysis was done by the Chi-square test using the SPSS version 17.0 software. A two-sided (α = 2) P < 0.05 (P < 0.05) was considered statistically significant.

Results

The null hypothesis was rejected. There was a statistically significant difference between the groups. All file systems created microcracks in the root dentin. WOG group showed an incidence of 66.7% for no fracture, PTN group had 40% for other fracture, and RS group had 60% for complete fracture.

Conclusion

Single file system WOG with gold wire technology proves to be the best choice for canal preparation among the tested groups in terms of least dentinal crack formation.

Micro-computed tomography evaluation of dentinal microcracks following canal preparation with thermomechanically heat-treated engine-driven files

This study aimed to evaluate and compare the frequency of microcracks and its severity at different root canal dentin locations, after preparation with thermomechanically heat‐treated engine‐driven nickel‐titanium instruments. Forty mandibular premolars were assigned to four experimental groups (n = 10): ProTaper Next, ProTaper Gold, WaveOne Gold and Reciproc Blue. After pre‐instrumentation micro‐computed tomography scans, the root canals were prepared to size 25. Following post‐instrumentation scans, pre‐ and post‐instrumentation scanned images were analysed for the presence and extent of dentinal defects. A total of 56 500 cross‐sectional images were obtained, showing that less than 2.3% with pre‐existing dentinal microcracks. No new microcracks were identified during the post‐instrumentation analyses. No significant association was found between the types of dentinal defects, file motions and sequences. Thermomechanically heat‐treated rotary files did not induce the formation of new microcracks. There was also no association between the kinematic motions and sequences of the rotary instruments to the types of dentinal defects.

Influence of Root Canal Preparation on Formation of Dentinal Microcracks: A Systematic Review

The effect of root canal preparation technique on microcrack initiation is a controversial issue. This systematic review aimed to assess the role of root canal preparation techniques with different kinematics (manual, rotary, reciprocating, adaptive, self-adjusting file) on microcrack initiation. In vitro and in situ studies comparing the influence of at least two different root canal preparation techniques on the initiation of dentin microcracks were searched in PubMed/MEDLINE and SCOPUS up to June 5, 2018 without language and period restriction. Two authors independently reviewed all identified titles and abstracts for eligibility. Tables were generated to summarize the included studies, and the included studies were assessed for bias. Fifty-four (n=54) articles met the eligibility criteria. The results were classified according to the method used for microcrack evaluation, and most studies that used micro-computed tomography showed no formation of new cracks after root canal preparation. In general, the instrumentation techniques induced microcrack formation when the methods were destructive, irrespective of kinematics. In relation to the apex region, when the preparation working length was set as the root canal length subtracted of 1 mm, the risk of microcrack initiation reduces. The majority of the included studies had low risk of bias for all assessed domains. Our results seem to indicate that the various root canal preparation techniques considered in this study will not cause damage to the dental structure when adequately employed and the proper methodology is applied.

Effect of Root Canal Preparation Techniques on Crack Formation in Root Dentin

INTRODUCTION

The aim of this study was to assess the frequency of root crack formation caused by the use of manual instrumentation, 2 rotary systems, and 1 reciprocating system using light-emitting diode transillumination.

METHODS

One hundred fifty mandibular premolars were randomly divided into 5 groups (n = 30): control 1, no intervention; control 2, instrumented with hand files; group 3, instrumented with ProTaper Universal rotary files (Dentsply Maillefer, Ballaigues, Switzerland); group 4, instrumented with OneShape rotary files (Micro-Mega, Besancon, France); and group 5: instrumented with the WaveOne reciprocal system (Dentsply Maillefer, Ballaigues, Switzerland). After root canal preparations, the roots were sectioned at 3, 6, and 9 mm from the apex with water irrigation. The slices were inspected under a stereomicroscope with light-emitting diode transillumination from the buccal, lingual, mesial, and distal directions at ×40 magnification to determine the presence/absence of cracks (dentinal defects). The chi-square test was used to analyze the data.

RESULTS

There was a significant difference among the groups in crack frequency (P < .05). The 2 single systems had significantly higher cracks than the other 3 groups. At 3 mm from the apex, there were significantly more cracks in groups 4 and 5 than in groups 1, 2, and 3 (P < .05). At 6 mm from the apex, no significant difference was noted (P > .05). At 9 mm from the apex, the frequency of cracks in group 3 was significantly higher (P < .05).

CONCLUSIONS

According to the results, using rotary instrumentation can result in some dentinal defects, and single-file systems, regardless of motion type, can cause significantly higher crack formation in the apical third of root canals.

Incidence of Dentinal Crack after Root Canal Preparation by ProTaper Universal, Neolix and SafeSider Systems

Introduction:

This study aimed to compare the incidence of dentinal crack formation by instrumentation with ProTaper Universal system (rotary, multi-file system), SafeSider (reciprocation movement, multi-file system) and Neolix (rotary, single-file system).

Methods and Materials:

In this in vitro study, 60 freshly extracted mandibular first molars were randomly divided into three experimental groups (n=15) and a control group containing unprepared teeth (n=15). Instrumentation in different groups was accomplished using either ProTaper, Neolix or SafeSider systems up to 25/0.08. The teeth were then sectioned at 3, 6 and 9 mm from the apex, and observed under a stereomicroscope for presence of dentinal cracks. Data were analyzed with Chi square test, Fisher’s exact test and Bonferroni correction.

Results:

Micro cracks were seen in all experimental groups (13.3% in ProTaper, 26.7% in SafeSider and 40% in Neolix). There was a significant difference between Neolix and the control groups in microcrack formation (P=0.042). Micro cracks mainly occurred in the coronal section (9 mm). No microcrack occurred in the control group.

Conclusion:

Neolix rotary single-file system caused more dentinal cracks compared to the unprepared roots. All the instrumentation systems increased the number of micro cracks compared to unprepared teeth.