Toggle Main Menu Toggle Search

Open Access padlockePrints

Aluminium radiopacity standards for dentistry: An international survey

Lookup NU author(s): Professor John McCabe

Downloads

Full text for this publication is not currently held within this repository. Alternative links are provided below where available.


Abstract

Objective: the aims of this study were to determine the appropriate composition and purity limits of aluminium alloy radiopacity standards for dental biomaterials, taking into account the current status in representative laboratories worldwide, and to formalise the calculation procedure for processing radiopacity data. Methods: a series of aluminium step-wedges were obtained from academic and industrial research laboratories. These were analysed by energy dispersive X-ray procedures. The set of step-wedges were independently characterised for radiopacity at two University dental schools. Results: the percentage of aluminium together with the percentages of minor alloying elements (magnesium, manganese, iron and silicon) have been determined as mass percentages. For each centre, the optical density versus step-height for all wedges was judged to fall on a common curve, with the main exception of one step-wedge that was found to contain 4% copper, by mass. A suitable calculation procedure was described explicitly. Conclusion: of the examined representative step-wedges, all but the aluminium-4% copper material were satisfactory and gave results comparable with wedges of high purity. Limits should therefore be revised for composition of aluminium radiopacity step-wedges or test blocks to a more realistic level of purity. Alloys with more than 0.05% copper or 1.0% iron should be excluded and the aluminium content should be at least 98% by mass. In the calculations deployed for deriving radiopacity as 'equivalent aluminium thicknesses', an appropriate linear regression procedure should be employed and considerable care taken in the evaluation of materials of low or borderline radiopacity, relative to specification limits. The method described is principally suitable for materials with radiopacity greater than 1 mm. For materials with radiopacity less than 1 mm aluminium, thicker specimens (2 mm) should be used. © 1998 Elsevier Science Ltd. All rights reserved.


Publication metadata

Author(s): McCabe JF; Watts DC

Publication type: Article

Publication status: Published

Journal: Journal of Dentistry

Year: 1999

Volume: 27

Issue: 1

Pages: 73-78

Print publication date: 04/01/1999

ISSN (print): 0300-5712

ISSN (electronic): 1879-176X

Publisher: Elsevier Ltd

URL: http://dx.doi.org/10.1016/S0300-5712(98)00025-6

DOI: 10.1016/S0300-5712(98)00025-6

PubMed id: 9922615


Altmetrics

Altmetrics provided by Altmetric


Share