Influence of thickener kind and hydrogen peroxide gel viscosity on the properties of the hydrogen peroxide gel

Author(s)

Sabrina Elise Moecke

• Document type: Master's Dissertation
• Press: São José dos Campos. 2020-11-30.
• Institution: Universidade Estadual Paulista (Unesp). Instituto de Ciência e Tecnologia. São José dos Campos
• Defense date: 2020-10-01
• Advisor: Carlos Rocha Gomes Torres

Abstract

The study evaluated how the thickening agent and the viscosity of a 35% hydrogen peroxide gel can influence the chemical reactions occurring inside the gel layer. 540 bovine incisors were used, from which 270 were used for color evaluation. The other 270 bovine incisors were used for gel changing evaluation. Experimental bleaching gels (hydrogen peroxide 35% and pH 6.5) were prepared using five thickening agents (CAR– Carbopol; SA– Salcare, ARI– Aristoflex, CMC– Carboxymethylcellulose, AER– Aerosil), which were added to produce gels with low (L - 50.000 cP), medium (M - 250.000 cP) and high (H – 1.000.000 cP) viscosities. In addition, three control groups were prepared: PC (Positive Control) – a hydrogen peroxide solution; CC (Commercial Control) – Whiteness HP, FGM; NC (Negative Control) – purified water. The bleaching gels were applied for 45 minutes over the specimens. The evaluation were performed for color change, and concentration change of peroxide, pH and free radicals. Data were statistically analyzed with two-way ANOVA (THICKNER AND VISCOSITY) and Tukey Test. For control groups comparison Dunnett test was used ( = 5%). Significant differences were observed for both factors for all measurements performed (p <0,05). For color change (ΔE*ab) Tukey Test results were: THICKNER - CMC 2.80(0.78)a, SA 2.81(0.8)a, AER 3.13(0.8)ab, CAR 3.24(1.05)ab, ARI 3.32(0.89)b; VISCOSITY - H 2.90(0.78)a, M 3.02(0.84)b, L 3.27(1.0)c. The results for peroxide concentration for THICKNER - CMC -4.86(1.85)a, AER -3.79(1.36)b, SA -3.53(0.74)b, ARI -3.48(1.21)b, CAR -2.5(1.40)c; VISCOSITY - H -4.41(2.16)a, M -3.26(0.91)b, L -3.23(0.92)b. The results for pH for THICKNER - SA -13.87(3.05)a, CAR -12.62(2.72)b, ARI -5.82(2.41)c, AER -4.94(1.42)d, CMC -4.43(1.68)e; VISCOSITY - H -9.22(5.82)a, M -8.8(4.88)b, L -6.99(2.34)c. The results for free radicals for THICKNER - SA 4.93a, CAR 6.83b, ARI 10.88c, AER 16.48d, CMC 29.76e; VISCOSITY - H 11.27a, M 13.82b, L 16.24c. The difference between NC and experimental groups certify the methods used and the efficiency of bleaching results. The similarity between CC and experimental groups results demonstrate the achievement of the expected bleaching result. Based on the results, it can be concluded that: The thickening agent and the gel viscosity significantly influence the product interaction with the dental structure and consequently on dental color. (AU)

• FAPESP's process: 18/06961-6 - Influence of thickener kind and hydrogen peroxide gel viscosity on the properties of the hydrogen peroxide gel
• Grantee: Sabrina Elise Moecke
• Support Opportunities: Scholarships in Brazil - Master