https://www.endoexperience.com/documents/FractureRotaryNiTiInstrumentFractureanditsConsequencesParashos2006.pdf

Rotary NiTi instrument fracture and its consequences.

The expanded use of nickel-titanium (NiTi) rotary instruments in root canal procedures has led to the development of a wide variety of shapes, designs and applications. Root canal anatomy has not changed, however, and the same challenges exist in both initial treatment and the revision of unacceptable treatment. These challenges include application with high levels of achievement and low to no levels of adverse effects, such as instrument fracture, root canal wall ledging, dentine wall perforation and so forth. To that end, many manufacturers have been seeking ways to alter the presently available and wide range of root canal instrument designs, with a focus on altering the surface of the alloy or altering the alloy microstructure with post-machining or post-twisting heat treatment. This focused review will address the impact that these modifications have had on instrument flexibility, resistance to cyclic fatigue and cutting efficiency.

Alteration in the inherent metallic and surface properties of nickel-titanium root canal instruments to enhance performance, durability and safety: a focused review.

Difficulties with the integration of CO 2 and Nd-YAG lasers into a machining centre have hitherto impeded industrial implementation of laser assisted machining technologies. The rapidly emerging new technology of high-power diode lasers holds potential in this regard, on account of the laser being compact and the feasibility of fiber optic beam transport. In comparison to other commercial systems, high-power diode lasers combine higher efficiency and metal absorption with lower capital and operating costs; however, their current metal processing applications are confined largely to surface hardening and joining, due to their lower power density. With a view to expanding their application envelope, the work presented in this paper explores high-power diode laser assisted turning of fully hardened AISI D2 tool steel, a material that is difficult to machine. Laser assist is shown to inhibit saw tooth chip formation, suppress chatter, deter catastrophic tool fracture and bring about a substantial reduction in tool wear and cutting forces, with minimal affect on the integrity of the machined surface.

High-power diode laser assisted hard turning of AISI D2 tool steel

Causes of failure and repairing options for dies and molds: A review

Microstructure and wear behavior of laser cladding VC–Cr7C3 ceramic coating on steel substrate

Comparison of wear properties of tool steels AISI D2 and O1 with the same hardness

Darabara M, Bourithis L, Zinelis S, Papadimitriou GD. Susceptibility to localized corrosion of stainless steel and NiTiendodontic instruments in irrigating solutions. InternationalEndodontic Journal, 37, 705–710, 2004. Aim To evaluate the pitting and crevice corrosioncharacteristics of stainless steel (SS) and NiTi endodon-tic ﬁles in R-EDTA and NaOCl irrigating solutions.Methodology The corrosion behaviour of twoH-ﬁles produced from different SS alloys (Mani, AISI303 SS, Dentsply Maillefer, AISI 304 SS) and one ﬁleproduced from NiTi alloy (Maillefer) was determined inR-EDTA and NaOCl irrigating solutions by the cyclicpotentiodynamic polarization method. The cuttingﬂutes of 12 ﬁles of each material were embedded inan epoxy resin, polished, exposed to the irrigatingsolutions and used as an electrode. An Ag/AgClelectrode was used as a reference, a platinum platewas used as a counter electrode and polarization curveswere obtained for all ﬁles in R-EDTA and NaOClirrigating solutions in 37 C with a potential scan rateof 5 mV min

https://www.endoexperience.com/filecabinet/Clinical%20Endodontics/Instruments%20-%20Files/Susceptibility%20to%20localized%20corrosion%20of%20stainless%20steel%20and.pdf

Susceptibility to localized corrosion of stainless steel and NiTi endodontic instruments in irrigating solutions

Metal Matrix Composites (MMC) with boron reinforcement exhibit significant increase in the mechanical strength and wear characteristics compared to matrix alloys. Titanium Diboride (TiB 2 ) particles have ideal properties for being used as reinforcing material due to their excellent mechanical and wear properties. This study enlightens the possibility of synthesizing Fe 2 B–TiB 2 MMC layers on the surface of a plain steel using the plasma transferred arc (PTA) technique. The microstructure of the final alloyed layers depends on the portion of B and TiB 2 powders used as covering material. TiB 2 covering results in a microstructure of primary titanium diboride particles in a eutectic mixture of iron and TiB 2 eutectic particles. Increasing B progressively leads to microstructures approximately described as hypoeutectic, eutectic or hypereutectic according to the Fe–B binary system, with the presence of TiB 2 grains uniformly distributed throughout the alloyed layer.

L. Bourithis

Papers

Comparison of wear properties of tool steels AISI D2 and O1 with the same hardness

Susceptibility to localized corrosion of stainless steel and NiTi endodontic instruments in irrigating solutions

Production of Fe–B–TiB2 metal matrix composites on steel surface

Assessment of elemental composition, microstructure, and hardness of stainless steel endodontic files and reamers.

Three body abrasion wear of low carbon steel modified surfaces