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Statistical Comparison of the Hardness and Scratch-Resistance of the PMMA Polymers Used in Orthodontic Appliances

Domagała Ivo, Gil Leszek, Firlej Marcel, Pieniak Daniel, Selech Jarosław, Romek Dawid, Biedziak Barbara

Advances in Science and Technology. Research Journal

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2020

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Vol. 14, no 4

250--261

EN

The paper presents the studies and results of the Shore hardness and scratch test of polymer materials used in medical devices. Polymers of organic PMMA (poly(methyl methacrylate)) origin for the manufacture of orthodontic appliances were tested. Samples of test materials differed in manufacturing technology. The surface functional properties of four materials were compared. Hardness tests were performed with the Shore D hardness test method. The scratch test was done with a Rockwell diamond cone indenter. The hardness was also calculated from the scratch test. Shore’s highest hardness was demonstrated in 1A material. But the differences in Shore’s hardness were small. Larger differences between the tested materials were shown in the scratch test than in the Shore hardness test. The lowest residual scratch depth (Rd) was obtained for 1A material. 3A material had the highest scratch hardness.

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Surface analysis for signs of corrosion of fixed orthodontic appliances used in vivo

Łępicka M., Grądzka-Dahlke M.

Advances in Materials Science

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2016

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Vol. 16, nr 3(49)

5--14

EN

The objective was to evaluate and assess the surface quality of fixed orthodontic appliances after intraoral usage for several months. Nine sets of orthodontic brackets by three different manufacturers and twelve archwires differing in chemical composition were analyzed in a scanning electron microscope with an energy dispersive X-ray analyzer for signs of corrosion. Obtained results showed that the majority of the evaluated appliances displayed no traces of corrosion. Machining or casting defects hardly ever act as the origins of corrosion processes. However, some samples displayed signs of corrosion of a galvanic and pitting nature. The authors claim, that despite the surface defects, most of the appliances were able to retain the desired corrosion resistance, although in some cases these flaws could act as the origin of corrosion processes.

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Instalacja do oceny stopnia uwalniania jonów metali ze stopów w warunkach in vitro

Wołowiec P., Mikulewicz M., Chojnacka K.

Przemysł Chemiczny

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2012

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T. 91, nr 5

1074-1077

PL

Przedstawiono koncepcję instalacji do oceny stopnia uwalniania jonów metali w warunkach in vitro ze stopów stali nierdzewnej stosowanych w ortodoncji. Skonstruowana aparatura składa się z termostatowanego szklanego reaktora, łaźni wodnej z obiegiem zewnętrznym, pompy perystaltycznej oraz mieszadła magnetycznego z funkcją grzania i kontrolą temperatury. Konstrukcja reaktora umożliwia symulację przepływu śliny, dzięki czemu w możliwie bliski sposób zostaną odwzorowane warunki panujące w jamie ustnej. W badaniach zostanie przeprowadzona ocena uwalniania jonów metali z aparatów ortodontycznych z wykorzystaniem różnych ekstrahentów.

EN

A review, with 31 refs., of construction materials used in orthodontic appliances and methods for testing their corrosion resistance in saliva. New test stand consisting of a thermostated glass reactor, water bath with an external circulation, peristaltic pump and a magnetic stirrer with heating function and temp. control was designed and constructed to study the metal ion leaching from stainless steel and nonferrous alloys. The program of the study was outlined.

4

Nowa koncepcja oceny narażenia pacjentów leczonych ortodontycznie na toksyczne metale

Mikulewicz M., Chojnacka K., Janeczek M., Zielińska A., Wołowiec P., Górecki H.

Przemysł Chemiczny

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2011

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T. 90, nr 5

923-926