Effect of Experimental Bleaching Gels With Enzymes on Composite and Enamel

Int Dent J. 2025 Apr;75(2):1234-1245. doi: 10.1016/j.identj.2024.08.014. Epub 2024 Sep 12.

Abstract

Introduction and aims: Potential secondary or toxic effects of peroxide-based whitening gels have driven the search for alternative methods that use natural compounds with gentle action on tooth enamel that provide remineralizing benefits.

Methods: This study introduces four innovative experimental whitening gels (GC, G1, G3, G4) formulated with enzymes (Bromelaine and Papaine) and natural extracts, along with SiO2. The efficacy of these gels was tested on nanohybrid dental composite (EsCOM100, Spident Company) and dental enamel stained with coffee and natural juice (Tedi) over 10 days. The structural changes in samples before and after bleaching were examined using scanning electron microscopy and atomic force microscopy. Additionally, cytotoxicity tests were conducted on the gels using mesenchymal stem cells from human dental pulp (dMSC) and human keratinocytes (HaCaT). Antibacterial activity was assessed on five strains (Streptococcus mutans. Porphyromonas gingivalis; Enterococcus faecalis; Escherichia coli; Staphylococcus aureus).

Results: Coffee and natural juice stains significantly increase the roughness of composite and enamel surfaces by forming deposits. The enzymatic action of bromelain and papain effectively disorganizes and removes these clusters, significantly reducing surface roughness.

Conclusion: Notably, the gel containing papain and nanostructured SiO2 proved to be the most effective in removing coffee stains from both composite surfaces and enamel. On the other hand, the gel with bromelain and nanostructured SiO2 was the most efficient in removing natural juice stains. The absence of SiO2 in the experimental gels slightly decreased the enzymes' effectiveness in stain removal. The antibacterial activity observed in the experimental gels is attributed solely to the enzymatic compounds.

Keywords: Bleaching gel; Bromelain; Papain; Stains removal.

MeSH terms

  • Anti-Bacterial Agents / pharmacology
  • Bromelains* / pharmacology
  • Coffee
  • Composite Resins* / chemistry
  • Dental Enamel* / drug effects
  • Dental Pulp / cytology
  • Dental Pulp / drug effects
  • Escherichia coli / drug effects
  • Gels
  • Humans
  • Microscopy, Atomic Force
  • Microscopy, Electron, Scanning
  • Papain* / pharmacology
  • Silicon Dioxide / pharmacology
  • Streptococcus mutans / drug effects
  • Surface Properties
  • Tooth Bleaching Agents* / pharmacology
  • Tooth Bleaching* / methods

Substances

  • Papain
  • Tooth Bleaching Agents
  • Gels
  • Bromelains
  • Composite Resins
  • Coffee
  • Silicon Dioxide
  • Anti-Bacterial Agents