Effect of Experimental Bleaching Gels With Enzymes on Composite and Enamel

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.

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).

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.

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.