Minimally-invasive dentistry via dual-function novel bioactive low-shrinkage-stress flowable nanocomposites

Ebtehal G Albeshir; Abdulrahman A Balhaddad; Heba Mitwalli; Xiaohong Wang; Jirun Sun; Mary Ann S Melo; Michael D Weir; Hockin H K Xu

doi:10.1016/j.dental.2021.12.023

Minimally-invasive dentistry via dual-function novel bioactive low-shrinkage-stress flowable nanocomposites

Dent Mater. 2022 Feb;38(2):409-420. doi: 10.1016/j.dental.2021.12.023. Epub 2021 Dec 30.

Authors

Ebtehal G Albeshir¹, Abdulrahman A Balhaddad², Heba Mitwalli³, Xiaohong Wang⁴, Jirun Sun⁵, Mary Ann S Melo⁶, Michael D Weir⁷, Hockin H K Xu⁸

Affiliations

¹ Ph.D. Program in Dental Biomedical Sciences, University of Maryland School of Dentistry, Baltimore, MD 21201, USA; Department of Restorative Dentistry, King Abdul-Aziz Medical City, Riyadh 11426, Saudi Arabia. Electronic address: ealbeshir@umaryland.edu.
² Ph.D. Program in Dental Biomedical Sciences, University of Maryland School of Dentistry, Baltimore, MD 21201, USA; Department of Restorative Dental Sciences, College of Dentistry, Imam Abdulrahman bin Faisal University, Dammam 31441, Saudi Arabia. Electronic address: aabalhaddad@umaryland.edu.
³ Ph.D. 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.
⁴ Volpe Research Center, American Dental Association Foundation, Frederick, MD 21704, USA.
⁵ The Forsyth Institute, A Harvard School of Dental Medicine Affiliate, 245 First Street, Cambridge, MA 02142, USA. Electronic address: jsun@forsyth.org.
⁶ 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.
⁷ Department of Advanced Oral Sciences and Therapeutics, School of Dentistry, University of Maryland, Baltimore, MD 21201, USA. Electronic address: michael.weir@umaryland.edu.
⁸ 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.

PMID: 34973816
DOI: 10.1016/j.dental.2021.12.023

Abstract

The objectives of this in vitro study were to develop a novel low-shrinkage-stress flowable nanocomposite with antibacterial properties through the incorporation of dimethylaminohexadecyl methacrylate (DMAHDM) and nanoparticles of amorphous calcium phosphate (NACP), and investigate the mechanical and oral biofilm properties, to be used in minimally-invasive techniques.

Methods: The light-cured low-shrinkage-stress flowable resin was formulated by mixing urethane dimethacrylate (UDMA) and triethylene glycol divinylbenzyl ether (TEG-DVBE) at a 1:1 mass ratio. Different mass fractions of glass, and either 5% DMAHDM or 20%NACP or both were incorporated. Paste flowability, ultimate micro tensile strength and surface roughness were evaluated. The antibacterial response of DMAHDM resin was assessed by using biofilms of human saliva-derived microcosm model. Virtuoso flowable composite was used as a control.

Results: (45% resin+5% DMAHDM+20% NACP+30% glass) formula yielded the needed outcomes. It had flow rate within the range of ISO requirement. The micro tensile strength was (39.1 ± 4.3) MPa, similar to (40.1 ± 4.0) MPa for commercial control (p > 0.05). The surface roughness values of the novel composite (0.079 ± 0.01) µm similar to commercial composite (0.09 ± 0.02) µm (p > 0.05). Salivary microcosm biofilm colony forming unit values were reduced by 5-6 logs (p < 0.05). Biofilm metabolic activity was also substantially reduced, compared to control composite (p < 0.05).

Significance: The novel bioactive flowable nanocomposite achieved strong antibacterial activities without compromising the mechanical properties. It is promising to be used as pit and fissure sealants, and as fillings in conservative cavities to inhibit recurrent caries and increase restoration longevity.

Keywords: Antibacterial monomer; Bioactive nanocomposite; Dental material; Flowable composite; Low polymerization stress; Minimally-invasive dentistry; Oral biofilm; Sealant; Secondary caries.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Anti-Bacterial Agents / pharmacology
Biofilms
Calcium Phosphates / pharmacology
Dentistry
Humans
Methacrylates* / pharmacology
Methylamines
Nanocomposites*

Substances

Anti-Bacterial Agents
Calcium Phosphates
Methacrylates
Methylamines
dimethylaminohexadecyl methacrylate