Testimonials: University of Tromsø

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"The hardness testing equipment will enable... a significant increase in the throughput of test specimens..."

The Customer

The University of Tromsø was established in 1968 and has a modern, technically advanced and well equipped campus. The university is an international institution contributing high quality research and scientific and artistic development. The campus includes 14 research centers and is particularly strong in marine based studies.

Oral health and dental health services in northern Norway have been inferior to the rest of the country, mainly due to lack of manpower. In 2002 the Norwegian Parliament therefore decided to establish dental education at the University of Tromsø (since 2013 The Arctic University of Norway). Dental education and research is organised by the Department of Clinical Dentistry integrated in the Faculty of Health Sciences. The department has the responsibility for a master program in dentistry, bachelor program for dental hygienists as well as three post graduate educations and research. The research is conducted in research groups and the department has collaboration partners within the university as well as national and international partners. Several of the staff members are also involved in international standardisation concerning biomaterials.

Hardness tester at Uni of Tromso
Hardness tester at Uni of Tromso

Zwick Roell Indentec ZHVμ-A hardness tester

The Challenge

The Department of Clinical Dentistry is leading research into biomaterials for dental purposes (e.g. dental prosthetics). New polymer (e.g plastics) technologies for both clinical and cosmetic applications are developing at a rapid pace and hardness is one of the essential characteristics of materials used in such areas. The department was therefore looking for state of the art equipment to determine hardness of new biomaterials. The equipment was required to reach international standards of metrology and also allow multiple tests without requiring supervision of laboratory technicians whose time is very valuable.

The Solution

The Department determined to take advantage of developments in image processing to seek an automatic Micro Vickers Hardness tester. It was decided that a fully automatic system would offer two significant benefits: it would free a technician's time to perform other tests and would remove operator influence from the results thereby increasing the repeatability and reproducibility of the results. It was also of importance that booth Vickers and Knoop hardness could be tested. In particular it was important that weight of indentation could be used with a high degree of accuracy.

Technical proposals were requested from several of the leading hardness tester manufacturers. Indentec offered the ZHVμ-A Vickers Hardness testing machine. The ZHVμ-A machine, which incorporates ZHμ.HD software, has user-friendly interfaces and extremely fast and reliable automatic indentation focus and measurement. In addition, Indentec could offer UKAS certified calibration and measurement capabilities unmatched by other bidders and traceability to the German National Physical Laboratory (PTB). The department was looking for trouble-free installation and running so installation by an Indentec UKAS certified calibration engineer was included as part of the tender.

It was also decided that, as a failsafe system a dual light path machine would be required so that manual measurement using the traditional eyepiece would also be possible. Indentec therefore manufactured a machine with a digital camera located safely within the body of the hardness tester and an external manual eyepiece.

The Result

"The hardness testing equipment will enable the Department of Clinical Dentistry to cater for a significant increase in the throughput of test specimens and, in particular, provide the scientific community with a greater understanding of modern biomaterials used in dentistry (and also in medicine)," stated Professor (Biomaterials) Ulf Örtengren.

"Indentec and Zwick demonstrated their ability to thoroughly understand the biomaterials researchers' exacting requirements and their ability to provide technical and service support of the installed product."

Current Research

The department is currently performing research on dental composite resins. This work is intended to evaluate the hardness of dental composite resins samples which are elaborated with different monomer composition. The objective is to determine a correlation between the material hardness and its degree of conversion (when the resin converted all its monomer to polymer during the polymerization reaction).

During the pilot study at least 200 indentations have been performed to get significant results. The possibility to automate our tests has been of great importance and saved a lot of time. As soon as the test parameters are set the hardness tester can operate almost without supervision. Moreover this feature increases the reproducibility and the repeatability of our results. Hence we got very consistent preliminary research results.

Future Perspective

Further research on polymerisation of polymer-based materials used in dentistry and medicine will be conducted as well as corrosion tests, evaluation of changes in the surface texture of dental biomaterials subjected to situations applicable to the clinical situation.

For further details please contact us.