Quantitative nano-mechanical mapping AFM-based method for elastic modulus and surface roughness measurements of model polymer infiltrated ceramics

Nada Alharbi; Supontep Teerakanok; Julian D Satterthwaite; Russel Giordano; Nick Silikas

doi:10.1016/j.dental.2022.03.002

Quantitative nano-mechanical mapping AFM-based method for elastic modulus and surface roughness measurements of model polymer infiltrated ceramics

Dent Mater. 2022 Jun;38(6):935-945. doi: 10.1016/j.dental.2022.03.002. Epub 2022 Mar 12.

Authors

Nada Alharbi¹, Supontep Teerakanok², Julian D Satterthwaite³, Russel Giordano⁴, Nick Silikas⁵

Affiliations

¹ Division of Dentistry, School of Medical Sciences, The University of Manchester, Manchester, UK; School of Dentistry, Taibah University, Madina, Saudi Arabia.
² Faculty of Dentistry, Prince of Songkla University, Songkhla, Thailand.
³ Division of Dentistry, School of Medical Sciences, The University of Manchester, Manchester, UK.
⁴ Department of Restorative Sciences/Biomaterials, Boston University, Boston, MA, USA.
⁵ Division of Dentistry, School of Medical Sciences, The University of Manchester, Manchester, UK. Electronic address: nick.silikas@manchester.ac.uk.

PMID: 35292156
DOI: 10.1016/j.dental.2022.03.002

Abstract

Objectives: The aim of this in vitro investigation was to assess and compare surface characteristics and nanomechanics of model polymer infiltrated ceramic network (PICN) materials compared to CAD/CAM resin composite blocks.

Material and methods: Four model PICN materials sintered at different temperatures (Exp.125, Exp.130, Exp.135 and Exp.155) were investigated along with three CAD/CAM resin composites; Lava Ultimate (LU), Cerasmart (CS) and Grandio Bloc (GB), and one commercial PICN block - Vita Enamic (VE). Forty samples were prepared with dimensions of 14 × 12 × 2 mm for resin ceramic and VE blocks and 15 × 2 mm discs for model PICN materials. All samples were scanned using atomic force microscopy (AFM) (n = 3) at multiple locations and two different scan sizes (20 ×20 µm and 3 ×3 µm). Surface optical gloss (n = 5) at 60° was also determined for all the groups. Data were analysed using one-way ANOVA, and Tukey's post hoc test (α = 0.05).

Results: Resin composite blocks showed smoother surfaces compared to the PICN materials. The average surface roughness values (Ra) ranged from 7.75 nm to 31.21 nm and the gloss value ranged from 56.43 GU to 91.81 GU. The highest surface roughness value was found for Exp.125 (31.21 nm) while LU showed the lowest roughness value (7.75 nm) (the difference being statistically significant: p = 0.001). Variation was noticed in terms of nanomechanical mapping within and between the groups. Images generated from the elastic modulus map values clearly indicated that all PICN materials had more than one phase and very different components.

Conclusions: CAD/CAM resin composite blocks exhibited higher gloss and lower roughness values compared to PICN materials. However, both the commercial and model PICN materials showed more stiffness than resin composite with the presence of at least two different phases. Sintering temperature appears to have a significant effect on material topography and nanomechanical properties. The model PICN sintered at 1550 °C showed a comparable range of elastic modulus values to those of enamel.

Keywords: Alumina; Atomic force microscopy; CAD/CAM; Elastic modulus; Polymer-infiltrated; Resin composites.

MeSH terms

Ceramics*
Composite Resins
Computer-Aided Design
Elastic Modulus
Materials Testing
Microscopy, Atomic Force
Polymers*
Surface Properties

Substances

Composite Resins
Polymers