Bioactivity and Physico-Chemical Properties of Dental Composites Functionalized with Nano- vs. Micro-Sized Bioactive Glass

Scientific paper - Original scientific paper

• Author: Reto Odermatt
• Author: Matej Par
• Author: Dirk Mohn
• Author: Daniel B. Wiedemeier
• Author: Thomas Attin
• Author: Tobias T. Tauböck
• Author's institution: University of Zagreb; School of Dental Medicine
• Scientific / art field, discipline and subdiscipline: BIOMEDICINE AND HEALTHCARE; Dental Medicine; Endodonics and Restorative Dentistry

Abstract (english)

Bioactive resin composites can contribute to the prevention of secondary caries, which is one of the main reasons for failure of contemporary dental restorations. This study investigated the effect of particle size of bioactive glass 45S5 on chemical and physical composite properties. Four experimental composites were prepared by admixing the following fillers into a commercial flowable composite: (1) 15 wt% of micro-sized bioactive glass, (2) 15 wt% of nano-sized bioactive glass, (3) a combination of micro- (7.5 wt%) and nano-sized (7.5 wt%) bioactive glass, and (4) 15 wt% of micro-sized inert barium glass. Hydroxyapatite precipitation and pH rise in phosphate-buffered saline were evaluated during 28 days. Degree of conversion and Knoop microhardness were measured 24 h after specimen preparation and after 28 days of phosphate-buffered saline immersion. Data were analyzed using non-parametric statistics (Kruskal–Wallis and Wilcoxon tests) at an overall level of significance of 5%. Downsizing the bioactive glass particles from micro- to nano-size considerably improved their capability to increase pH. The effect of nano-sized bioactive glass on degree of conversion and Knoop microhardness was similar to that of micro-sized bioactive glass. Composites containing nano-sized bioactive glass formed a more uniform hydroxyapatite layer after phosphate-buffered saline immersion than composites containing exclusively micro-sized particles. Partial replacement of nano- by micro-sized bioactive glass in the hybrid composite did not impair its reactivity, degree of conversion (p > 0.05), and Knoop microhardness (p > 0.05). It is concluded that downsizing bioactive glass particles to nano-size improves the alkalizing potential of experimental composites with no negative effects on their fundamental properties.

• Keywords (english): dental resin composites; bioactive glass filler; nanoparticles; microhardness; degree of conversion; hydroxyapatite
• Language: english
• Publication type: Scientific paper - Original scientific paper
• Publication status: Published
• Peer review: Peer review - international
• Publication version: Published version
• Journal title: Journal of Clinical Medicine
• Numbering: vol. 9, no. 3, 772
• e-ISSN: 2077-0383
• DOI: https://doi.org/10.3390/jcm9030772
• URN:NBN: urn:nbn:hr:127:906464
• Publication: 2020-03-12
• Document URL: https://www.mdpi.com/2077-0383/9/3/772
• Type of resource: Text
• Access conditions: Open access
• Created on: 2022-11-11 10:07:04