Structural Analysis of NiTi Endodontic Instruments: A Systematic Review.

Introduction: Irregularities and defects on NiTi endodontic instruments originating from the manufacturing process can lead to the structural collapse and fracture of these instruments during treatment. To assess the cause of instrument wear and fracture, as well as increasing fracture incidence, destructive and non-destructive methods have been used for the analysis of surfaces and internal structures of new and used NiTi instruments. The aim of this systematic review was to undertake a detailed analysis of the methods used to evaluate the surface and internal microstructure of endodontic instruments.

How can we reduce the risks of SARS-CoV-2 (COVID-19) for dentists and their patients?

Design Special report.Study population This paper presented a report about the experience of the oral and maxillofacial surgeons (OMS) of Peking University School and Hospital of Stomatology, during the COVID-19 (SARS-CoV-2) pandemic.Data analysis The experience of that department formed the content of the report.

In vitro cytotoxicity of dental adhesives: A systematic review.

Objectives: The increased demand for esthetics and minimally invasive tooth restorations resulted in a rapid development of adhesive dentistry. However, much controversy remains about the safe use and cytotoxic effects of different groups of dental adhesives. The present study performed a systematic review to identify the answer to the following question: are self-etch adhesives more cytotoxic than those employing the etch-and-rinse system?

Methods: This systematic review was performed in accordance with the PRISMA statement; a quality assessment for in vitro studies was conducted using the ToxRTool.

Noncontact three-dimensional evaluation of surface alterations and wear in NiTi endodontic instruments.

The aim of this study was to undertake a qualitative and quantitative assessment of nanoscale alterations and wear on the surfaces of nickel-titanium (NiTi) endodontic instruments, before and after use, through a high-resolution, noncontact, three-dimensional optical profiler, and to verify the accuracy of the evaluation method. Cutting blade surfaces of two different brands of NiTi endodontic instruments, Reciproc R25 (n = 5) and WaveOne Primary (n = 5), were examined and compared before and after two uses in simulated root canals made in clear resin blocks. The analyses were performed on three-dimensional images which were obtained from surface areas measuring 211 × 211 µm, located 3 mm from their tips.

A comparison of two reciprocating instruments using bending stress and cyclic fatigue tests.

The aim of this study was to comparatively evaluate the bending resistance at 45º, the static and dynamic cyclic fatigue life, and the fracture type of the WaveOne (Dentsply Maillefer, Ballaigues, Switzerland) 25-08 and Reciproc (VDW, Munich, Germany) 25-08 instruments. A total of 60 nickel-titanium (NiTi) instruments (30 Reciproc and 30 WaveOne) from three different lots, each of which was 25 mm in length, were tested. The bending resistance was evaluated through the results of a cantilever-bending test conducted using a universal testing machine.