BACKGROUND/PURPOSE Dental rotary instruments can be applied in multiple conditions of canals, but unpredictable fatigue fracture may happen. This study evaluated the fatigue lives of two batches of nickel-titanium (NiTi) dental rotary files operating in clinically simulated root canals. METHODS Single-step cyclic fatigue tests were carried out to assess the performance of two batches of NiTi ...

Objective. The objective of this study was to evaluate the efficacy of two retreatment NiTi systems (protaper universal retreatment files, R-Endo), when compared to manual technique in removing Gutta-percha obturated with two sealers. Study Design. Sixty extracted single-rooted premolars were instrumented with Protaper rotary files till F3. The specimens were divided into six groups. Groups 1, ...

BACKGROUND The cleaning of endodontic and all dental instruments prior to sterilization is a prerequisite for their processing for re-use. This study aimed to develop a clinically practical cleaning protocol for rotary nickel-titanium (NiTi) endodontic files prior to sterilization. METHODS Cleaning experiments were conducted on six different types of files that had been used on human teeth. T...

The purpose of this project was to observe the amount of apical and mid-curve transportation produced by a range of nickel titanium (NiTi), titanium alloy and stainless steel (SS) files. Tests were carried out in simulated curved root canals produced in epoxy resin blocks. Seven commercially available file types were tested using sizes 15 to 40. Instrumentation was carried out to 1 mm beyond th...

PURPOSE The aim of this study was to compare the cleanliness of root canal walls after retreatment using ProTaper Next (PTN), ProTaper Universal Retreatment (PTR) nickel-titanium (NiTi) systems and Hedström hand files in curved mesial canals of mandibular molar teeth and the time required for gutta-percha and sealer removal. MATERIALS AND METHODS Ninety mandibular molar teeth with curved mesi...

The growing use of NiTi rotary instruments in dental practice demands a good understanding of their concept of alloy and design in relation to improved properties and inherent limitations. Nickel titanium's super elasticity allows more centered canal preparations with less transportation and a decreased incidence of canal aberrations. Furthermore, the production of files with increased taper be...

introduction: the purpose of the present study was to quantify and compare the amount of extruded debris from apical foramen after instrumentation of the root canal system with hand and rotary instruments. materials and methods: root canals of forty five fresh extracted single rooted human teeth with mature apexes and less than 15 degree of root curvature were instrumented in group a with stain...

There have been significant advancements in the development of NiTi rotary instruments in recent years. This evolution is driven by market demand and the continuous improvement in the manufacturing process. Dentists have increasingly identified the features they deem essential on the endless journey towards a more perfect file. These features include flexibility, efficiency, safety, and simplic...

Of all the procedural problems that can occur when practicing dentistry, endodontic file breakage is one dilemma that not only can lead to extreme stress for the clinician, but can cause great anxiety for the patient as well. Separated rotary nickel-titanium (NiTi) files can also pose an increased risk of post-endodontic complications. Understanding why and how endodontic file breakage occurs, ...

Aim: To evaluate the strength of an endodontically treated tooth after preservation of peri-cervical dentin and soffit. Methodology: 30 human molars having well developed cusps and morphology were extracted for periodontal reasons were included in this study. They were divided in two groups. In gp. A, ClarkKhademi access was made and endodontic treatment was carried out with 2% NiTi K-files and...