Affiliations 

  • 1 Joshua Ee Xin Ong, BDS, MJDF RCS, MOSc, Centre of Restorative Dentistry Studies, Faculty of Dentistry, MARA University of Technology, Malaysia
  • 2 Adrian U-Jin Yap, BDS, MSc, PhD, Grad Dip Psychotherapy, Department of Dentistry, Ng Teng Fong General Hospital, National University Health System, Singapore
  • 3 Azwatee Abdul Aziz, BDS, MClinDent, PhD, Department of Restorative Dentistry, Faculty of Dentistry, University of Malaya, Malaysia
  • 4 *Noor Azlin Yahya, DipTrans, BDS, MDentSci, Department of Restorative Dentistry, Faculty of Dentistry, University of Malaya, Malaysia
Oper Dent, 2023 Jan 01;48(1):90-97.
PMID: 36445974 DOI: 10.2341/21-202-L

Abstract

This study investigated the effects of environmental pH on the flexural properties of ion-releasing restorative materials (IRMs), including giomer (Beautifil-Bulk Restorative - BB), alkasite (Cention N - CN), bioactive composite (Activa - AB) and resin-modified glass ionomer (Riva Light Cure -RV) restoratives. A bio-inert resin-based composite (Filtek Bulk-fill Posterior - FB) served as the control. Stainless steel molds were used to fabricate 40 beam-shaped specimens (12mm × 2mm × 2mm) for each material. The specimens were finished, measured, and randomly distributed into four groups (n=10) and immersed in aqueous solutions of pH 3.0, pH 5.0, pH 6.8, and pH 10.0 at 37°C for 28 days. Specimens were then subjected to a uniaxial three-point bending flexural test with a load cell of 5 KN and a fixed deformation rate of 0.5 mm/min until fracture occurred. Flexural modulus and strength were statistically analyzed using analysis of variance/Dunnet T3's test (p=0.05). Mean flexural modulus varied from (2.40±0.41 to 9.65±1.21 GPa), while mean flexural strength ranged from (21.56±2.78 to 163.86±13.13 MPa). Significant differences in flexural properties were observed among the various pH values and materials. All materials immersed in artificial saliva (pH 6.8) presented the highest flexural properties, except AB. The flexural strength of AB was significantly better when exposed to acidic environments. FB had better flexural properties than IRMs after exposure to a range of environmental pH values.

* Title and MeSH Headings from MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.