Evolution and development: engine-driven endodontic rotary nickel-titanium instruments

Electrochemical Properties of Nickel-Titanium Rotary Endodontic Instruments

INTRODUCTION

Nickel-titanium rotary endodontic files have been commercially available for decades, but more recent innovations have introduced heat-treated and surface-treated files. This study investigated the corrosion properties of various nickel-titanium files in normal saline and sodium hypochlorite (NaOCl).

METHODS

Ten different file brands of size 40 with a 0.04 taper were subjected to electrochemical testing in 0.9% NaCl (saline) and 5.25% NaOCl at room temperature. The Open Circuit Potential (OCP) was observed for 1 hour followed by a cyclic polarization test from -300 to 700 mV and back to -300 mV (vs OCP). Nonparametric ANOVA and a pairwise comparison (P < .05) were used for statistical analysis of the OCP at 1 hour and the corrosion current (Icorr) obtained via the cyclic polarization test.

RESULTS

Significant differences (P < .05) were found between files with respect to OCP and Icorr in both solutions. Nine files exhibited significantly greater (P < .05) Icorrs in NaOCl than in saline. Conversely, pitting corrosion was observed in the saline solution but not NaOCl. Weak and/or moderate correlations existed between OCP and Icorr measures in the 2 solutions.

CONCLUSION

Significant differences in electrochemical properties were observed among the 10 brands of files. Overall, there was not a clear trend between conventional, heat-treated, or surface-treated files among OCP or Icorr in either solution.

Substance P/calcitonin gene-related peptide and their receptors expression in human periodontal ligament after root canal preparation with five different systems

AIM

The purpose of this study was to quantify the effect of five different root canal preparation instruments on Substance P (SP), Calcitonin gene-related peptide (CGRP) and their receptors expression in healthy human periodontal ligament.

METHODOLOGY

STROBE guidelines were used to design a study using 60 periodontal ligament samples obtained from healthy lower premolars where extraction was indicated for orthodontic reasons. Prior to extraction 40 of these premolars were equally divided into four groups and root canals were prepared using different systems: Mtwo, Reciproc Blue, HyFlex EDM and Plex-V. Ten premolars were prepared with hand files and served as a positive control group. The remaining 10 premolars where extracted without treatment and served as a negative control group. All periodontal ligament samples were processed to measure the expression of SP, CGRP and their receptors by radioimmunoassay. Kruskal-Wallis and Duncan tests were performed to determine statistically significant differences between the groups for each variable.

RESULTS

Greater expression of all the peptides measured were found in the hand-file preparation group, followed by the Reciproc Blue, Mtwo, HyFlex EDM and Plex-V groups. The lower SP, CGRP and their receptors values were for the intact teeth control group. Kruskal-Wallis test showed statistically significant differences amongst groups (p < .001). Dunn post-hoc tests showed statistically significant differences in SP, CGRP and their receptors expression between the intact teeth and the hand-file and Reciproc Blue groups. Hand-file group showed significant differences with the other groups, except with Reciproc Blue, where no differences were observed in any of the peptides measured. Finally, no differences were observed between Plex-V and HyFlex in any of the peptides measured.

CONCLUSIONS

Root canal preparation with hand files and Reciproc Blue generates the highest expression of SP, CGRP, NK1 and CGRP1R in human periodontal ligament, whilst Plex-V and HyFlex maintain the basal expression of neuropeptides and their receptors. Mtwo showed intermediate results between Reciproc Blue and HyFlex.

Root Canal Instrumentation: Current Trends and Future Perspectives

The evolution of root canal instrumentation techniques has significantly impacted the field of endodontics, enhancing both the efficiency and outcomes of treatments. This review outlines the transition from manual to mechanical and rotary instruments, highlighting the role of nickel-titanium (NiTi) alloys and smart technologies in advancing procedural precision and reducing patient discomfort. Key historical developments and technological innovations, such as digital imaging and navigation systems, are explored for their contributions to improved clinical outcomes and patient satisfaction. Additionally, the review addresses the challenges presented by the complex anatomy of the root canal system and the advent of current instrumentation techniques. The potential of emerging trends, including artificial intelligence and advances in materials science, is discussed in the context of future endodontic practices. Despite the progress, challenges related to using advanced instrumentation methods, ethical considerations, and the cost factor of new technologies persist. The present review underscores the ongoing need for research and development to further refine root canal instrumentation techniques, ensuring that advancements in endodontic care remain patient-centered and accessible.

Can instrumentation kinematics affect postoperative pain and substance P levels? A randomized controlled trial

BACKGROUND

This study aimed to assess the influence of continuous rotation and reciprocation kinematics on postoperative pain (POP) levels and substance P (SP) levels in patients diagnosed with irreversible pulpitis and symptomatic apical periodontitis (SAP).

MATERIALS AND SUBJECTS

A total of twenty patients were randomly assigned into two groups: Continuous Rotation Group (CRG) (n = 10), subjected to mechanical preparation with the EdgeEndox7 rotary system (Albuquerque, NM, USA), and Reciprocation Group (RG) (n = 10), treated with the EdgeOne Fire reciprocating system (Albuquerque, NM, USA). Apical fluid (AF) samples were collected, and SP levels were quantified through radioimmunoassay. POP was assessed using the Numerical Rating Scale (NRS) at various time intervals (preoperatively, 6 h, 12 h, 24 h, 48 h, and 72 h). Data were statistically analyzed utilizing the independent t-test, Mann-Whitney U test, Friedman's test, and Nemenyi post hoc test.

RESULTS

There was a significant increase in SP levels in the reciprocating group compared to the continuous rotation group (P ≤ 0.05). Additionally, patients in the reciprocating group reported significantly higher POP levels (P ≤ 0.05) at all measured intervals (6 h, 12 h, 24 h, and 48 h), with both groups exhibiting similar pain level reductions at the 72-hour mark.

CONCLUSION

Our findings suggest that continuous rotation kinematics in root canal preparation leads to a considerable reduction in SP expression and POP.

TRIAL REGISTRATION

The study protocol was retrospectively registered on the www.

CLINICALTRIALS

gov database (NCT06081335) at (13/10/2023) after the approval of the Ethics Committee, Faculty of Dentistry, Ain Shams University (FDASU-RecIM012135).

Life span of Neoendo Flex and ProTaper Next rotary files with reciprocating motion in single-rooted teeth

Background

Cleaning and shaping represent a vital step in the endodontic procedure. In routine endodontic therapy, the fracture of nickel-titanium (NiTi) instruments is a procedural problem creating a major obstacle to therapy.

Aim

This study examines the life span of one Neoendo Flex and ProTaper Next (PTN) rotary file using reciprocating motion and compares the time required by both file systems for canal preparation.

Materials and Methods

One hundred maxillary permanent central incisors were selected. In that, fifty teeth are utilized in a reciprocating motion (RM) with the PTN file (n = 25) and Neoendo Flex file (n = 25). To check fractured resistance and the overall root canal preparation time, fifty more teeth are employed in continuous motion (CM) with canals prepared using PTN (n = 25) and Neoendo Flex (n = 25). All canals are prepared following the sequence of respective files. Later, the fracture mechanism of the files was inspected using a scanning electron microscope.

Results

In an RM motion, both PTN and Neoendo Flex files can be used in a minimum of 25 canals in single-rooted teeth. Statistical analysis using the Mann-Whitney U-test showed no significant difference in total time taken by PTN and Neoendo Flex in both motions.

Conclusion

Within the limitation of this study, the RM was found to be better than CM with less incidence of instrument fracture.

A review of the latest developments in rotary NiTi technology and root canal preparation

The introduction of nickel-titanium (NiTi) mechanical instruments dramatically changed clinical endodontics over the last few decades. Before NiTi, it was necessary to use more instruments to create an ideal root canal shape, and many approaches, sequences and techniques were developed over the years. Recently, NiTi endodontic instruments have undergone a series of changes brought about by modifications in design, surface treatments, and thermal treatments to improve their root canal preparation outcomes and reduce associated canal preparation risks during root canal treatment. Heat treatment is one of the most fundamental approaches to improving the fatigue resistance and flexibility of NiTi endodontic instruments. In addition, new kinematics have been developed to offer greater safety and efficiency. This narrative review describes the general properties and manufacturing of NiTi instruments, and the mechanical system evolution of NiTi instruments.

Evaluating occupational exposures of dental nurses: A retrospective study

Objective

The objective of this study was to investigate occupational blood-borne pathogen exposure among dental nurses and their attitudes toward infected patients, as well as the effectiveness of the training course, to provide a scientific basis for improving the quality of safety management in the dental hospital.

Materials and methods

The study was conducted using questionnaires administered from November 2019 to December 2019 in three hospitals in Sichuan Province, China. Frequencies for answers were calculated and presented as percentages.

Results

In total, 257 valid questionnaires were returned. Most (61.9%) nurses stated that they were involved in occupational exposure. Among them, 154 had experienced sharp injuries, and the syringe needle was the most common instrument for injuries (45.8%). Twenty-two individuals had mucosal exposure, and the proportion of eye exposure was the highest (90.9%). Only associations between training and mucosal membrane exposure were found; however, the relevance was weak (r = 0.141). Of the participants, 86.4% felt morally responsible for taking care of patients with infectious diseases, and most (92.6%) said they would continue with this career.

Conclusion

Occupational exposure, particularly to sharp injuries, was common in medical care among dental nurses; however, vocational training had little effect on their incidence. As dental nurses still have positive attitudes toward patients with infectious diseases, more effective training should be conducted.

Knowledge, awareness, and perception on root canal treatment among South Indian population - A survey

The pulp is removed, and the interior of the tooth is cleaned and sealed during root canal treatment. Root canals are dreaded by many people because they are considered to be painful. The following are indicators of pulpal damage, color changes, swelling, thermal sensitivity, and pain in the gums. The pulp gets inflamed or diseased when it becomes infected, then RCT or extraction is needed to eliminate the inflamed or infected tissue and heal that particular region. The questionnaire was circulated to the sample population through a Google Docs link. Pie charts with a frequency table were created when the survey data were acquired. The Chi-square test was used to evaluate the connection using the SPSS software. Eighty-four percent of people are aware of RCT and what it is intended for and 80% of the participants themselves have undergone endodontic treatment. Most of the South Indian population were aware of root canal treatment and have undergone an RCT procedure.

A Comparative Study of Two Martensitic Alloy Systems in Endodontic Files Carried out by Unskilled Hands

The aim of this study was to compare the behavior of two heat-treated file systems on resin blocks in unskilled hands. For this purpose, an in vitro, randomized, cross-sectional study was conducted to compare ProTaper Gold (PTG) with BlueShaper (BS) files. A total of 81 resin blocks were used and analyzed photographically to assess the amount of material removed during instrumentation. PTG removed more material on the outside of the curve in the coronal and apical third, while BS removed more material on the inner part of the curve in the middle third. The procedural errors observed in the total sample were apical transportation (33.8%), blockages (4.9%), ledges (3.7%), and canal perforation. PTG produced more apical transportation, and there were no statistically significant differences between the groups in the formation of ledges, canal perforations, or blockages. No file fractures were recorded during the study. Within the limitations of this study, we can affirm that neither file excessively deformed the artificial canals, and the PTG file produced more apical transportation.