Complex and Neutralize VSC by using Zinc Containing Toothpaste

Objectives: To evaluate the Volatile Sulfur Compounds (VSC) neutralization efficacy of Zinc containing toothpaste as compared to a control toothpaste.
Methods: Volatile sulfur compounds (VSCs) produced in the oral cavity is a major cause of oral malodor. Hydrogen sulfide is one of the most prevalent VSCs involved in oral malodor that have a distinct unpleasant odor even in extremely low concentrations. In this study, an in-vitro method was developed to mimic the generation of VSCs from saliva and the concentration of hydrogen sulfide in the headspace was measured using gas chromatography. Agilent 7890B GC system is equipped with 7697A headspace auto-sampler and flame photometric detector to measure the hydrogen sulfide. A series of hydrogen sulfide standard samples were prepared and measured to validate the GC method. After method validation, the saliva solution was treated with toothpaste with or without zinc, and hydrogen sulfide was measured to investigate the VSC reduction efficacy of toothpaste.
Results: Retention time of hydrogen sulfide was determined as 5.4 minutes in the developed GC method. A linear response was observed between the hydrogen sulfide concentration and the logarithm of GC integrated peak area (R2=0.98). Method validation was completed with high accuracy (RSD=4.7%). Study showed that after treatment of toothpaste containing zinc, hydrogen sulfide was below detection limit. While for treatment of control toothpaste without zinc, the integrated area of hydrogen sulfide was 6.59 *10⁶.
Conclusions: An in-vitro hydrogen sulfide measurement method was developed and result showed that a zinc containing toothpaste effectively neutralized hydrogen sulfide as a major component of volatile sulfur compounds.