Preparation and Characterization of Natural Bleaching Gels Used in Cosmetic Dentistry

Abstract

The novelty of this study consists of the formulation and characterization of three experimental bleaching gels with hydroxylapatite oxides and fluorine (G28®, G29®, G30®) based on natural fruit extracts compared to the commercial Opalescence 15% (GC, Ultradent, South Jordan, UT, USA). Studies have been conducted on the effect that the experimental bleaching gels have on the color and morphology of different restorative materials (Nanofill®-Schulzer, P.L. Superior Dental Materials GmbH, Hamburg, Germany, and experimental nanocomposites (P11®, P31®, P61®)), immersed in coffee and artificial saliva (for 10 days and 30 days). The study also includes a cytotoxicity test on the gels and nanocomposites after bleaching, with ISO 109993-5 protocols on human dental follicle stem cells. UV-VIS spectroscopy, computerized measurement, and fluorescence spectrometry were used in order to observe the color changes, while the microstructure of the surface was investigated by Scanning Electron Microscopy (SEM). All of the samples immersed in coffee showed the highest color shift in comparison to the baseline. The color difference ΔE values obtained using the two methods (UV-Vis, computerized based on digital images) both after coloring and bleaching, respectively, were different for all four types of nanocomposites stored in the coffee, while no difference was observed in those stored in artificial saliva. The studied experimental gels and nanocomposites had a low cytotoxic effect on cell cultures after bleaching.

Preparation and In Vitro Characterization of Gels Based on Bromelain, Whey and Quince Extract

“…Toothpastes based on proteolytic enzymes have proven their effectiveness by removing tooth stains, this being done with reduced roughness [ 5 ]. Indeed, for dental applications—such as toothpaste or whitening solutions—the main candidates as alternatives to peroxides are cysteine-protease enzymes, such as papain and bromelain, described as active agents with whitening potential [ 5 , 20 , 21 , 22 , 23 ]. Proteases disrupt or remove the portion of protein in the film layer that forms on the surface of the teeth, thus removing the pigments that are bound to them.…”

An Evaluation of the Demineralizing Effects of Various Acidic Solutions

“…Case reports and other studies suggest that dietary acid erosion is playing a significant role in tooth wear [35,36]. How demineralizing a solution is depends on the type of acid it contains, its pH value, its acid concentration and its temperature [37][38][39][40][41][42][43]. The results of this in vitro study show that acids in liquid state are more harmful to the dental hard tissues than gels; therefore, beverages and acid reflux represent a greater concern.…”

Calcium-Polyphosphate Submicroparticles (CaPP) Improvement Effect of the Experimental Bleaching Gels’ Chemical and Cellular-Viability Properties

“…The MTT reduction method was performed to determine the viability of MDPC-23 cells after exposure to the bleaching gels. The MDPC-23 cells were cultured in Dulbecco's modified Eagle's medium (DMEM, Sigma-Aldrich, St. Louis, MO, USA) supplemented with antibiotics, 100 IU/mL penicillin and 100 µg/mL streptomycin (Vitrocell Embriolife, Campinas, Brazil), 2 mmol/L glutamine, and 10% fetal bovine serum (FBS-GIBCO; Thermo Fisher Scientific, Waltham, MA, USA) at 37 • C in a 5% CO 2 atmosphere [39,46].…”