Available online 22 February 2024, 104021

The low concentrations of photocatalytic nanoparticles, such as emodin (≤0.5%), curcumin (≤0.5%), curcumin nisin (≤5%), and Ulva lactuca (≤1%), could be incorporated into orthodontic acrylic resins without compromising flexural strength.

The addition of zinc oxide (≤2%) and titanium dioxide (≤3%) to acrylic resins improved flexural strength.

Titanium dioxide was found to be the most prevalent photocatalytic nanoparticle.

Orthodontic acrylic resins containing antimicrobial photocatalytic nanoparticles aims to reduce oral lesions including denture stomatitis and white spot lesions but they should not imperil its mechanical properties. This systematic review was done to evaluate the effect of various photocatalytic nanoparticles on the flexural strength (FS) of acrylic resins.

We systematically searched the PubMed/Medline, Cochrane Library, and Scopus databases from January 2018 to October 2023. The review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, and the quality of the studies was evaluated using the QUIN tool, which is specifically designed to assess the risk of bias in in vitro studies.

Following screening of 1016 initial records, 23 studies were deemed eligible for inclusion. The addition of photocatalytic nanoparticles, such as emodin (Emo), curcumin (Cur), Cur nisin (CurNis), zeolite/zinc oxide (Zeo/ZnO), and Ulva lactuca (U. lactuca), to acrylic resins resulted in a reduction in FS, with the extent of reduction dependent on the nanoparticle concentration. Specifically, the addition of Emo (≥0.5%), Cur (≥0.5%), CurNis (≥5%), Zeo/ZnO (≥2), and U. lactuca (≥1%) to acrylic resins significantly decreased FS. Conversely, the inclusion of ZnO and titanium dioxide (TiO2) in acrylic resins improved FS, but higher concentrations (≥5% for TiO2) had a limited positive effect.

Our study supports the use of low concentrations of photocatalytic nanoparticles, such as ZnO (≤2%), TiO2 (≤3%), Emo (≤0.5%), Cur (≤0.5%), CurNis (≤5%), and U. lactuca (≤1%), in orthodontic acrylic resins without compromising FS.

Nanoparticles

Photocatalytic

Poly methyl methacrylate

Flexural strength

Antimicrobial

© 2024 Published by Elsevier B.V.