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International Journal of Oral Science Feb 2022Various engine-driven NiTi endodontic files have been indispensable and efficient tools in cleaning and shaping of root canals for practitioners. In this review, we... (Review)
Review
Various engine-driven NiTi endodontic files have been indispensable and efficient tools in cleaning and shaping of root canals for practitioners. In this review, we introduce the relative terms and conceptions of NiTi file, including crystal phase composition, the design of the cutting part, types of separation. This review also analysis the main improvement and evolution of different generations of engine-driven nickel-titanium instruments in the past 20 years in the geometric design, manufacturing surface treatment such as electropolishing, thermal treatment, metallurgy. And the variety of motion modes of NiTi files to improve resistance to torsional failure were also discussed. Continuous advancements by the designers, provide better balance between shaping efficiency and resistance to of NiTi systems. In clinical practice an appropriate system should be selected based on the anatomy of the root canal, instrument characteristics, and operators' experience.
Topics: Dental Alloys; Dental Instruments; Equipment Design; Nickel; Root Canal Preparation; Titanium
PubMed: 35181648
DOI: 10.1038/s41368-021-00154-0 -
Brazilian Oral Research Oct 2018The introduction of automated instrumentation in endodontics represented a major advance in progress for this specialty, with improvements in the quality and... (Review)
Review
The introduction of automated instrumentation in endodontics represented a major advance in progress for this specialty, with improvements in the quality and predictability of root canal preparation and a significant reduction in procedural errors. In recent years, endodontic instruments have undergone a series of changes brought about by modifications in design, surface treatments, and thermal treatments. In addition, new movements have also been incorporated to offer greater safety and efficiency, optimizing the properties of the NiTi alloy, especially through eccentric rotary motion. An understanding of the mechanical properties of these new NiTi instruments and their effect on the clinical performance of root canal preparation is essential if dental practitioners are to select the instruments that provide optimal clinical outcomes, especially in curved or flattened canals. The objective of this literature review is to present and discuss the characteristics of the NiTi alloys used in the major instrumentation systems available in the market, as well as the influence of the metallurgical and mechanical properties of NiTi instruments and the movements that drive them, to enable more accurate and predictable planning of root canal preparation.
Topics: Alloys; Dental Alloys; Dental Instruments; Equipment Design; Humans; Root Canal Preparation; Surface Properties
PubMed: 30365608
DOI: 10.1590/1807-3107bor-2018.vol32.0067 -
British Dental Journal Apr 2021
Topics: Dental Alloys; Orthodontic Appliance Design; Orthodontic Brackets
PubMed: 33893403
DOI: 10.1038/s41415-021-2970-7 -
Journal of Oral Science 2018The castability, mechanical properties, and fracture characteristics of Ti-15Mo-5Zr-3Al alloy were compared with those of Ti-6Al-7Nb alloy and pure titanium (CP Ti) for...
The castability, mechanical properties, and fracture characteristics of Ti-15Mo-5Zr-3Al alloy were compared with those of Ti-6Al-7Nb alloy and pure titanium (CP Ti) for application of this β-type titanium alloy in cast dental prostheses. Cast specimens were prepared with a centrifugal casting machine. A tensile test was performed according to ISO standard 22674. The castability index for Ti-15Mo-5Zr-3Al was lower than those for Ti-6Al-7Nb and CP Ti. The tensile strength of Ti-15Mo-5Zr-3Al was 852 MPa, which was lower than that of Ti-6Al-7Nb and higher than that of CP Ti. The proof strength of Ti-15Mo-5Zr-3Al was 799 MPa, which was comparable to that of Ti-6Al-7Nb and higher than that of CP Ti. The elastic modulus of Ti-15Mo-5Zr-3Al was 81.0 GPa, which was lower than the values for Ti-6Al-7Nb and CP Ti. Elongation of Ti-15Mo-5Zr-3Al was 5.1%, which was comparable to that of Ti-6Al-7Nb and less than that of CP Ti. The shape of the fractured segment was narrower for Ti-15Mo-5Zr-3Al than for Ti-6Al-7Nb and CP Ti. The deformation characteristics of Ti-15Mo-5Zr-3Al may result in decreased stress relative to increased strain during plastic deformation in the stress-strain diagram. In conclusion, Ti-15Mo-5Zr-3Al alloy has a low elastic modulus and exhibits limited ductile plastic deformation in cast dental prostheses.
Topics: Biocompatible Materials; Dental Alloys; Dental Casting Technique; Dental Stress Analysis; Elastic Modulus; Oxides; Tensile Strength; Titanium
PubMed: 29925713
DOI: 10.2334/josnusd.17-0280 -
Australian Dental Journal Mar 2017Adverse effects can arise from the clinical use of orthodontic materials, due to the release of constituent substances (ions from alloys and monomers, degradation... (Review)
Review
Adverse effects can arise from the clinical use of orthodontic materials, due to the release of constituent substances (ions from alloys and monomers, degradation by-products, and additives from polymers). Moreover, intraoral aging affects the biologic properties of materials. The aim of this review is to present the currently identified major adverse effects of the metallic and polymeric components found in orthodontic appliances and materials. Corrosion in metallic orthodontic attachments releases metal ions, mainly iron, chromium, and nickel. The latter has received the greatest attention because of its reported potential for an allergic response. The formation of an oxide layer may inhibit the outward movement of ions, thereby acting as an obstacle for release. Titanium alloys have superior corrosion resistance than stainless steel. The efficiency of polymerisation is considered an essential property for all polymers. A poor polymer network is susceptible to the release of biologically reactive substances, such as bisphenol-A (BPA), which is capable of inducing hormone-related effects. The close proximity of a light-curing tip to the adhesive, pumice prophylaxis after bonding, indirect irradiation and mouth rinsing during the first hour after bonding may decrease BPA release. The adverse effects of some orthodontic materials should be considered during material selection and throughout orthodontic treatment, in order to minimise possible undesirable implications.
Topics: Benzhydryl Compounds; Corrosion; Dental Alloys; Humans; Hypersensitivity; Metals, Heavy; Orthodontic Appliances; Phenols
PubMed: 28297095
DOI: 10.1111/adj.12473 -
Dental Materials : Official Publication... Aug 2022Titanium (Ti) is considered bioinert and is still regarded as the "gold standard" material for dental implants. However, even 'commercial pure' Ti will contain minor...
OBJECTIVE
Titanium (Ti) is considered bioinert and is still regarded as the "gold standard" material for dental implants. However, even 'commercial pure' Ti will contain minor fractions of elemental impurities. Evidence demonstrating the release of Ti ions and particles from 'passive' implant surfaces is increasing and has been attributed to biocorrosion processes which may provoke immunological reactions. However, Ti observed in peri-implant tissues has been shown to be co-located with elements considered impurities in biomedical alloys. Accordingly, this study aimed to quantify the composition of impurities in commercial Ti dental implants.
METHODS
Fifteen commercial titanium dental implant systems were analyzed using inductively coupled plasma-mass spectrometry (ICP-MS) and optical emission spectrometry (ICP-OES).
RESULTS
The elemental composition of implants manufactured from commercially pure grades of Ti, Ti-6Al-4V, and the TiZr alloy (Roxolid) conformed to the respective ISO/ASTM standards or manufacturers´ data (TiZr/Roxolid). However, all implants investigated included exogenous metal contaminants including Ni, Cr, Sb, and Nb to a variable extent. Other contaminants detected in a fraction of implants included As and the radionuclides U-238 and Th-232.
SIGNIFICANCE
Although all Ti implant studies conformed with their standard compositions, potentially allergenic, noxious metals and even radionuclides were detected. Since there are differences in the degree of contamination between the implant systems, a certain impurity fraction seems technically avoidable. The clinical relevance of these findings must be further investigated, and an adaptation of industry standards should be discussed.
Topics: Alloys; Dental Alloys; Dental Implants; Spectrum Analysis; Surface Properties; Titanium; Uranium
PubMed: 35781168
DOI: 10.1016/j.dental.2022.06.028 -
Journal of Oral Science Sep 2012There are several benefits in using adhesive technique in removable prosthodontics as well as fixed prosthodontics. Previous studies have examined denture-base surface... (Review)
Review
There are several benefits in using adhesive technique in removable prosthodontics as well as fixed prosthodontics. Previous studies have examined denture-base surface treatments that improve bond strength between a denture base resin and autopolymerizing repair resin. Dichloromethane and ethyl acetate are organic solvents that swell the denture base surface, thereby permitting diffusion of the acrylic resin. The optimal treatment duration is 5-10 s for dichloromethane and 120 s for ethyl acetate. It was reported that the bond durability of dichloromethane was superiorto that of ethyl acetate. Bonding between metal components and the denture base resin has an important role in the longevity of removable prostheses. The combination of metal conditioners and alumina air-abrasion is effective in fabricating and repairing removable dentures. Acidic monomers (4-META and MDP) are appropriate for base metal alloys, including Co-Cr alloy and titanium alloy, while thione monomers (MTU-6 and VBATDT) are suitable for noble metal alloys such as gold alloy and silver-palladium-copper-gold (Ag-Pd-Cu-Au) alloy. As an alternative to conventional restorations, resin-bonded restorations can provide precisely parallel guide planes with well-made rest seats. Careful consideration should be paid to stabilizing loosened teeth by fixing them with resin-bonded splints or fixed partial dentures.
Topics: Acetates; Dental Abutments; Dental Alloys; Dental Bonding; Dental Clasps; Denture Bases; Denture Repair; Denture, Partial, Removable; Humans; Methylene Chloride; Periodontal Splints; Resin Cements; Solvents; Surface Properties; Tooth Mobility; Tooth Preparation, Prosthodontic
PubMed: 23047030
DOI: 10.2334/josnusd.54.205 -
Journal of Oral Science 2022This study investigated whether additive manufactured (AM) surfaces inhibit accumulation of bacterial biofilm on the surfaces of Ti-6Al-4V alloy dental implants....
PURPOSE
This study investigated whether additive manufactured (AM) surfaces inhibit accumulation of bacterial biofilm on the surfaces of Ti-6Al-4V alloy dental implants. Bacterial biofilms are thought to cause peri-implant disease, which develops in mucosa surrounding titanium (Ti) and Ti alloy dental implants and can lead to bone loss and implant failure.
METHODS
Accumulation of a Streptococcus mutans (ATCC 25175) biofilm on Ti-6Al-4V alloy was compared in relation to fabrication method, ie, AM using electron beam melting (EBM) or laser beam melting (LBM). Conventional lost-wax casting was used as positive control, and Teflon was used as negative control. Biofilm accumulation on the alloys and negative control (each n = 10) was conducted at 37°C under anaerobic conditions. After 4 h, the number of metabolically active S. mutans bacteria adhering to the alloy was determined with a bioluminescence assay.
RESULTS
The quantitative roughness values of the specimens, before exposure to bacteria, ranked EBM > LBM > cast > Teflon.
CONCLUSION
The amount of biofilm accumulation on the investigated AM metals and cast metal controls did not significantly differ.
Topics: Alloys; Biofilms; Dental Alloys; Titanium
PubMed: 35370181
DOI: 10.2334/josnusd.21-0521 -
Indian Journal of Dental Research :... 2009Titanium and its alloys are used in dentistry for implants because of its unique combination of chemical, physical, and biological properties. They are used in dentistry... (Review)
Review
Titanium and its alloys are used in dentistry for implants because of its unique combination of chemical, physical, and biological properties. They are used in dentistry in cast and wrought form. The long term presence of corrosion reaction products and ongoing corrosion lead to fractures of the alloy-abutment interface, abutment, or implant body. The combination of stress, corrosion, and bacteria contribute to implant failure. This article highlights a review of the various aspects of corrosion and biocompatibility of dental titanium implants as well as suprastructures. This knowledge will also be helpful in exploring possible research strategies for probing the biological properties of materials.
Topics: Biocompatible Materials; Corrosion; Dental Alloys; Dental Implants; Dental Restoration Failure; Electrogalvanism, Intraoral; Humans; Saliva; Titanium
PubMed: 19336868
DOI: 10.4103/0970-9290.49068 -
Dental Materials Journal 2016The mechanical properties -tensile strength, yield strength, elongation after fracture, and Vickers hardness- and alloy phases of the dental cast alloys Ti-6%Nb-4%Cu,...
The mechanical properties -tensile strength, yield strength, elongation after fracture, and Vickers hardness- and alloy phases of the dental cast alloys Ti-6%Nb-4%Cu, Ti-18%Nb-2%Cu, and Ti-24%Nb-1%Cu were investigated. Ti-6%Nb-4%Cu consisted of a single α-phase, while Ti-18%Nb-2%Cu and Ti-24%Nb-1%Cu consisted of α- and β-phases. The tensile strengths, yield strengths, and hardnesses of these alloys were higher than those of Ti-5%Cu and Ti-30%Nb; however, their breaking elongations were smaller. These differences in the mechanical properties are attributable to solid-solution strengthening or to precipitation strengthening by the dual-phase (α+β) structure. Thus, Ti-Nb-Cu alloys are suitable for use in high-strength dental prostheses, such as implantretained superstructures and narrow-diameter implants.
Topics: Alloys; Dental Alloys; Hardness; Materials Testing; Tensile Strength; Titanium
PubMed: 27477221
DOI: 10.4012/dmj.2015-354