Novel riboflavin/VE-TPGS modified universal dentine adhesive with superior dentine bond strength and self-crosslinking potential

U Daood; Salvatore Sauro; Malikarjuna Rao Pichika; Hanan Omar; Seow Liang Lin; A S Fawzy

doi:10.1016/j.dental.2019.11.003

Novel riboflavin/VE-TPGS modified universal dentine adhesive with superior dentine bond strength and self-crosslinking potential

Dent Mater. 2020 Jan;36(1):145-156. doi: 10.1016/j.dental.2019.11.003. Epub 2019 Dec 7.

Authors

U Daood¹, Salvatore Sauro², Malikarjuna Rao Pichika³, Hanan Omar⁴, Seow Liang Lin¹, A S Fawzy⁵

Affiliations

¹ Clinical Dentistry Division, Restorative Division, School of Dentistry, International Medical University Kuala Lumpur, 126, Jalan Jalil Perkasa 19, Bukit Jalil 57000, Wilayah Persekutuan Kuala Lumpur, Malaysia.
² Dental Biomaterials and Minimally Invasive Dentistry, Departmento de Odontologia, Facultad de Ciencias de la Salud Universidad, CEU-Cardenal Herrera, Spain.
³ Department of Pharmaceutical Chemistry, School of Pharmacy, International Medical University Kuala Lumpur, 126, Jalan Jalil Perkasa 19, Bukit Jalil 57000, Wilayah Persekutuan Kuala Lumpur, Malaysia.
⁴ Missouri School of Dentistry and Oral Health (MOSDOH) - ATSU, United States.
⁵ UWA Dental School, University of Western Australia, 17 Monash Avenue, Nedlands, WA 6009, Australia. Electronic address: amr.fawzy@uwa.edu.au.

PMID: 31818524
DOI: 10.1016/j.dental.2019.11.003

Abstract

Objective: To modify a universal dentine adhesive with different concentrations of riboflavin and D-Alpha 1000 Succinate polyethylene (VE-TPGS) as a chemical enhancer and to assess the micro-tensile bond strength (24h/12 months), determine resin penetration, measurement of intermolecular interactions and cytotoxicity.

Materials and methods: An experimental adhesive system based on bis-GMA, HEMA and hydrophobic monomer was doped with RF0.125 (RF - Riboflavin) or RF/VE-TPGS (_0.25/0.50) and submitted to μTBS evaluation. Resin dentine slabs were prepared and examined using SEM and TEM. Adhesion force was analysed on ends of AFM cantilevers deflection. Quenched peptide assays were performed using fluorescence scanner and wavelengths set to 320nm and 405nm. Cytotoxicity was assessed using human peripheral blood mononuclear cell line. Molecular docking studies were carried out using Schrödinger small-molecule drug discovery suite 2018-2. Data from viable cell results was analyzed using one-way ANOVA. Bond strength values were analysed by two-way ANOVA. Nonparametric results were analyzed using a Kruskal-Wallis test at a 0.05 significance level.

Results: RF/VE-TPGS_0.25 groups showed highest bond strength results after 24-h storage in artificial saliva (p<0.05). RF/VE-TPGS_0.50 groups showed increased bond strength after 12-months of ageing. RF/VE-TPGS modified adhesives showed appreciable presence of a hybrid layer. Packing fraction indicated solid angle profiles describing well sized density and topology relations for the RF/VE-TPGS adhesives, in particular with the RF/VE-TPGS_0.50 specimens. Qualitative analysis of the phenotype of macrophages was prominently CD163+ in the RF/VE-TPGS_0.50. Both the compounds showed favourable negative binding energies as expressed in terms of 'XP GScore'.

Conclusion: New formulations based on the incorporation of RF/VE-TPGS in universal adhesives may be of significant potential in facilitating penetration, distribution and uptake of riboflavin within the dentine surface.

Keywords: Bond strength; Crosslinking; Dentine; Hybrid; Molecular docking; Riboflavin.

Publication types

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

MeSH terms

Dental Bonding*
Dental Cements
Dentin
Dentin-Bonding Agents*
Humans
Leukocytes, Mononuclear
Materials Testing
Molecular Docking Simulation
Resin Cements
Riboflavin
Surface Properties
Tensile Strength
Vitamin E

Substances

Dental Cements
Dentin-Bonding Agents
Resin Cements
Vitamin E
tocophersolan
Riboflavin