The basis of modern tooth whitening systems is the use of a whitening gel, which usually contains hydrogen peroxide or carbamide peroxide. The study included 81 patients aged 22 to 35 years with a tooth color A2 and a darker color on the Vita Classic scale. The purpose of our research was to identify a new approach to whitening teeth to improve safety and gentleness. To perform this, we assessed the effect of the tooth whitening procedure on the mineral composition of the oral fluid. A new approach to the teeth whitening procedure was to use a mouth retractor and a tool for aspirating the whitening gel, which we developed. Before the procedure, a protective film-forming aerosol, which included sodium ascorbate, was applied. After the tooth whitening procedure, the enamel was remineralized with a sealing liquid for 14 days. The concentrations of calcium and phosphorus in the oral fluid were determined using a spectrophotometer with a set of reagents (Human). The results obtained indicate that the new approach to the teeth whitening procedure contributed to less pronounced changes in the concentrations of calcium (+29.07, p < 0.001) and phosphorus (-14%, p < 0.001) in the oral fluid immediately after the procedure and in combination with the standard procedure for teeth whitening; immediately after this procedure, the calcium concentration increased by 74.4% (p < 0.001), and the phosphorus concentration decreased by 23.07% (p < 0.001). The use of remineralizing agents led to a faster recovery of the initial levels of calcium and phosphorus in the oral fluid.