Effect of magnesium oxide nanoparticles on the flexural strength, surface roughness, and color of self-cure PMMA provisional crowns
Abstract
This in vitro study evaluated the effects of magnesium oxide (MgO) nanoparticles on the flexural strength, surface roughness, and color characteristics of a self-cure polymethyl methacrylate (PMMA) provisional crown material. A commercially available PMMA resin was modified with 0.3, 0.5, or 1.0% w/w MgO nanoparticles, while unmodified resin served as the control. A total of 144 specimens were prepared and allocated equally among the four groups for the three outcome assessments. Surface roughness was measured using a contact profilometer, flexural strength was determined using a three-point bending test according to ISO 4049, and color coordinates were recorded using a spectrophotometer in the CIE L*a*b* system. Data were analyzed using the Kruskal–Wallis test followed by Dunn’s post-hoc test with Holm correction. Surface roughness differed significantly among the groups ( p = 0.008), with the 1.0% MgO group exhibiting significantly lower roughness than the control. Flexural strength also differed significantly ( p < 0.001); the 0.5 and 1.0% MgO groups showed significantly higher values than the 0.3% group, while none differed significantly from the control. L* and b* did not differ significantly among the groups, whereas a* showed a significant shift ( p < 0.001). Control-referenced ΔE*ab values derived from the group mean CIELAB coordinates remained below established perceptibility and acceptability thresholds. Within the limitations of this study, 1.0% MgO reduced surface roughness while maintaining flexural strength and overall color characteristics comparable to the control.
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BibTeX
@article{kotian2026effect,
title = {{Effect of magnesium oxide nanoparticles on the flexural strength, surface roughness, and color of self-cure PMMA provisional crowns}},
author = {Preetham Kotian and I. N. Aparna and Gayathri Krishnamoorthy and Gauri Shahi and Shilpa S. Prabhu and Prajna Pramod Nayak},
journal = {Scientific Reports},
year = {2026},
month = oct,
doi = {10.1038/s41598-026-74371-0},
url = {https://www.nature.com/articles/s41598-026-74371-0},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Effect of magnesium oxide nanoparticles on the flexural strength, surface roughness, and color of self-cure PMMA provisional crowns
AU - Preetham Kotian
AU - I. N. Aparna
AU - Gayathri Krishnamoorthy
AU - Gauri Shahi
AU - Shilpa S. Prabhu
AU - Prajna Pramod Nayak
PY - 2026
DA - 2026/10/14
JO - Scientific Reports
DO - 10.1038/s41598-026-74371-0
UR - https://www.nature.com/articles/s41598-026-74371-0
AB - This in vitro study evaluated the effects of magnesium oxide (MgO) nanoparticles on the flexural strength, surface roughness, and color characteristics of a self-cure polymethyl methacrylate (PMMA) provisional crown material. A commercially available PMMA resin was modified with 0.3, 0.5, or 1.0% w/w MgO nanoparticles, while unmodified resin served as the control. A total of 144 specimens were prepared and allocated equally among the four groups for the three outcome assessments. Surface roughness was measured using a contact profilometer, flexural strength was determined using a three-point bending test according to ISO 4049, and color coordinates were recorded using a spectrophotometer in the CIE L*a*b* system. Data were analyzed using the Kruskal–Wallis test followed by Dunn’s post-hoc test with Holm correction. Surface roughness differed significantly among the groups ( p = 0.008), with the 1.0% MgO group exhibiting significantly lower roughness than the control. Flexural strength also differed significantly ( p < 0.001); the 0.5 and 1.0% MgO groups showed significantly higher values than the 0.3% group, while none differed significantly from the control. L* and b* did not differ significantly among the groups, whereas a* showed a significant shift ( p < 0.001). Control-referenced ΔE*ab values derived from the group mean CIELAB coordinates remained below established perceptibility and acceptability thresholds. Within the limitations of this study, 1.0% MgO reduced surface roughness while maintaining flexural strength and overall color characteristics comparable to the control.
SN - 2045-2322
ER -