Artigos Científicos

Elemental analysis of commercial zirconia dental implants - Is “metal-free” devoid of metals?


Link: https://www.sciencedirect.com/science/article/pii/S1751616120303131?fbclid=IwAR1rrGQGDU1ocyFM4X-vISkJchvjMIaD3au9V8lqSUyi-Oybs3lQx4HleiY#undfig1
 

ChristianThomasBergfeldtbTobiasFretwurstaRenéRothweileraKatjaNelsonaAndresStrickera

 

Journal of the Mechanical Behavior of Biomedical Materials

Volume 107, July 2020, 103759 

https://doi.org/10.1016/j.jmbbm.2020.103759

 

Abstract

Objectives

The interest in ceramic dental implants made of yttria-stabilized tetragonal zirconia polycrystals (Y-TZP) or alumina toughened zirconia (ATZ) has increased in recent years. However, in the light of aging, corrosion, and potential impurities of zirconia ceramics, the material composition of these implants and the associated term “metal-free” is persistently questioned. Thus, the present study aimed to conduct an elemental analysis of commercial zirconia dental implants to specify their elemental composition and to identify contaminants.

Methods

Nine commercial zirconia dental implant systems and corresponding material samples were analyzed using inductively coupled plasma-mass spectrometry (ICP-MS) and optical emission spectrometry (ICP-OES).

Results

While the elemental composition was dominated by the main components Zr, Y and Al (in ATZ samples), all investigated samples contained impurities with Hf and contamination with alkali and alkali earth elements (Na, K, Mg, Ca), essential trace elements (e.g. Fe, Cu, Zn) but also potentially noxious metal elements (e.g. Ni, Cr). Furthermore, ultra-trace level contamination with the radionuclides U-238 and Th-232 was found in the majority of samples.

Significance

The results indicate that, although all the investigated Y-TZP and ATZ dental implants meet the currently relevant ISO standards and manufacturer's specifications, from an elemental point of view, they are not devoid of metals. Due to the lack of a universal definition and thresholds for the term “metal-free”, the question of whether the examined zirconia dental implants can be holistically classified as “metal-free” or not remains a controversial, philosophical one.
 

Special attention to:

All investigated samples contained impurities with Hf and contamination with alkali and alkali earth elements (Na, K, Mg, Ca), essential trace elements (Fe, Cu, Zn) but also potentially noxious metal elements (Ni, Cr).

Portuguese: 

Todas as amostras investigadas continham impurezas com Hf e contaminação com elementos alcalinos e alcalino-terrosos (Na, K, Mg, Ca), oligoelementos essenciais (Fe, Cu, Zn), mas também elementos metálicos potencialmente nocivos (Ni, Cr).

 



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