Abstract
Objectives: The objective of this study was to investigate selected physical properties of nine contemporary and recently marketed glass ionomer cement (GIC) and four resin-modified glass ionomer cement (RMGI) dental restorative materials. Materials and methods: Specimens (n = 12) were fabricated for fracture toughness and flexure strength using standardized, stainless steel molds. Testing was completed on a universal testing machine until failure. Knoop hardness was obtained using failed fracture toughness specimens on a microhardness tester, while both flexural modulus and flexural toughness was obtained by analysis of the flexure strength results data. Testing was completed at 1 h, 24 h, 1 week, and then at 1, 3, 6, and 12 months. Mean data was analyzed with Kruskal-Wallis and Mann-Whitney (p = 0.05). Results: Physical properties results were material dependent. Physical properties of the GIC and RMGI products were inferior at 1 h compared to that at 24 h. Some improvement in selected physical properties were noted over time, but development processes were basically concluded by 24 h. A few materials demonstrated improved physical properties over the course of the evaluation. Conclusions: Under the conditions of this study:1.GIC and RMGI physical property performance over time was material dependent;2.Polyalkenoate maturation processes are essentially complete by 24 h;3.Although differences in GIC physical properties were noted, the small magnitude of the divergences may render such to be unlikely of clinical significance;4.Modest increases in some GIC physical properties were noted especially flexural modulus and hardness, which lends support to reports of a maturing hydrogel matrix;5.Overall, GIC product physical properties were more stable than RMGI;6.A similar modulus reduction at 6 months for both RMGI and GIC produced may suggest a polyalkenoate matrix change; and7.Globally, RMGI products demonstrated higher values of flexure strength, flexural toughness, and fracture toughness than GIC materials. Clinical relevance: As compared to RMGI materials, conventional glass ionomer restorative materials demonstrate more stability in physical properties.
Original language | English |
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Pages (from-to) | 1295-1308 |
Number of pages | 14 |
Journal | Clinical Oral Investigations |
Volume | 23 |
Issue number | 3 |
DOIs | |
State | Published - Mar 8 2019 |
Bibliographical note
Publisher Copyright:© 2018, Springer-Verlag GmbH Germany, part of Springer Nature.
Keywords
- Glass ionomer
- Hydrogel matrix
- Physical property testing
- Polyalkenoate
- Resin modified glass ionomer
ASJC Scopus subject areas
- General Dentistry