Comparison of TISAB II and III for salivary fluoride determination: addressing a bioanalytical challenge in fluoride analysis

BACKGROUND: Accurate determination of salivary fluoride (F) depends on appropriate analytical conditions, particularly the buffering system used before ion-selective electrode measurements. RESEARCH DESIGN AND METHODS: This laboratory-based analytical study addressed the practical challenge of selecting between two total ionic strength adjustment buffers (TISAB II and TISAB III) for salivary F-determination using samples obtained from previously conducted clinical trials. Unstimulated saliva from eight participants was collected at baseline and at 5 min, 30 min, 1 h, 4 h, and 12 h after exposure to three F-treatments: F-varnish, 1,450 ppm F-dentifrice, and 5,000 ppm F-dentifrice. F-concentrations were measured using an F-ion-selective electrode after buffering with either TISAB II or TISAB III. Data were analyzed using paired statistical tests and Pearson correlation analysis (α = 0.05). RESULTS: < 0.001), and no differences were detected in the area under the concentration-time curve. CONCLUSIONS: These findings indicate that both TISAB II and TISAB III provide comparable analytical performance for salivary fluoride determination under the tested conditions, although differences may occur at lower fluoride concentrations.