Novel rechargeable calcium fluoride dental nanocomposites

Heba Mitwalli; Rashed AlSahafi; Abdullah Alhussein; Thomas W Oates; Mary Anne S Melo; Hockin H K Xu; Michael D Weir

doi:10.1016/j.dental.2021.12.022

Novel rechargeable calcium fluoride dental nanocomposites

Dent Mater. 2022 Feb;38(2):397-408. doi: 10.1016/j.dental.2021.12.022. Epub 2021 Dec 31.

Authors

Heba Mitwalli¹, Rashed AlSahafi², Abdullah Alhussein³, Thomas W Oates⁴, Mary Anne S Melo⁵, Hockin H K Xu⁶, Michael D Weir⁷

Affiliations

¹ Program in Dental Biomedical Sciences, University of Maryland School of Dentistry, Baltimore, MD 21201, USA; Department of Restorative Dental Science, College of Dentistry, King Saud University, Riyadh 11451, Saudi Arabia. Electronic address: hmitwalli@umaryland.edu.
² Program in Dental Biomedical Sciences, University of Maryland School of Dentistry, Baltimore, MD 21201, USA; Department of Restorative Dental Sciences, College of Dentistry, Umm Al-Qura University, Makkah 24211, Saudi Arabia. Electronic address: rashed.alsahafi@umaryland.edu.
³ Program in Dental Biomedical Sciences, University of Maryland School of Dentistry, Baltimore, MD 21201, USA; Department of Restorative Dental Science, College of Dentistry, King Saud University, Riyadh 11451, Saudi Arabia. Electronic address: aalhussein@umaryland.edu.
⁴ Department of Advanced Oral Sciences and Therapeutics, School of Dentistry, University of Maryland, Baltimore, MD 21201, USA. Electronic address: TOates@umaryland.edu.
⁵ Department of Advanced Oral Sciences and Therapeutics, School of Dentistry, University of Maryland, Baltimore, MD 21201, USA; Division of Operative Dentistry, Department of General Dentistry, University of Maryland School of Dentistry, Baltimore, MD 21201, USA. Electronic address: MMelo@umaryland.edu.
⁶ Department of Advanced Oral Sciences and Therapeutics, School of Dentistry, University of Maryland, Baltimore, MD 21201, USA; Center for Stem Cell Biology & Regenerative Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, USA; Marlene and Stewart Greenebaum Cancer Center, University of Maryland School of Medicine, Baltimore, MD 21201, USA. Electronic address: HXu2@umaryland.edu.
⁷ Department of Advanced Oral Sciences and Therapeutics, School of Dentistry, University of Maryland, Baltimore, MD 21201, USA. Electronic address: michael.weir@umaryland.edu.

PMID: 34974900
DOI: 10.1016/j.dental.2021.12.022

Abstract

Objectives: Composite restorations with calcium fluoride nanoparticles (nCaF₂) can remineralize tooth structure through F and Ca ion release. However, the persistence of ion release is limited. The objectives for this study were to achieve long-term remineralization by developing a rechargeable nCaF₂ nanocomposite and investigating the F and Ca recharge and re-release capabilities.

Methods: Three nCaF₂ nanocomposites were formulated: (1) BT-nCaF₂:Bisphenol A glycidyl dimethacrylate (BisGMA) and triethylene glycol dimethacrylate (TEGDMA); (2) PE-nCaF₂:Pyromellitic glycerol dimethacrylate (PMGDM) and ethoxylated bisphenol A dimethacrylate (EBPADMA); (3) BTM-nCaF₂:BisGMA, TEGDMA, and Bis[2-(methacryloyloxy)ethyl] phosphate (Bis-MEP). All formulations contained 15% nCaF₂ and 55% glass particles. Initial flexural strength and elastic modulus, F and Ca ion release, recharge and re-release were tested and compared to three commercial fluoride-containing materials.

Results: BT and BTM nCaF₂ composites were 3-4 times stronger and had elastic modulus 2 times that of resin-modified glass ionomer controls. PE-nCaF₂ had comparable strength to RMGIs. All nCaF₂ composites had significant F and Ca ion release and ion rechargeability. In F and Ca recharging cycles, PE-nCaF₂ had the highest ion recharging capability among nCaF₂ groups, followed by BT-nCaF₂ and BTM-nCaF₂ (p < 0.05). For all recharge cycles, ion release maintained similar levels, demonstrating long-term ion release was possible. Furthermore, after the final recharge cycle, nCaF₂ nanocomposites provided continuous ion release for 42 days without further recharge.

Significance: Novel nCaF₂ rechargeable nanocomposites exhibited significant F and Ca ion release over multiple recharge cycles, demonstrating continuous long-term ion release. These nanocomposites are promising restorations with lasting remineralization potential.

Keywords: Calcium fluoride ion release; Dental caries inhibition; Nanoparticles of calcium fluoride; Rechargeability; Remineralization; Resin composites.

MeSH terms

Calcium Fluoride*
Calcium Phosphates / chemistry
Composite Resins / chemistry
Flexural Strength
Fluorides
Materials Testing
Nanocomposites* / chemistry

Substances

Calcium Phosphates
Composite Resins
Calcium Fluoride
Fluorides