Adding Nitrate to a Sucrose Rinse Reduces Acidogenicity: An in vivo Study

Consuelo A Silva-Acevedo; Bob T Rosier; Cesia J Vargas; Alex Mira; Livia M A Tenuta; Constanza E Fernández

doi:10.1159/000549489

Adding Nitrate to a Sucrose Rinse Reduces Acidogenicity: An in vivo Study

Caries Res. 2025 Nov 24:1-11. doi: 10.1159/000549489. Online ahead of print.

Authors

Consuelo A Silva-Acevedo¹, Bob T Rosier², Cesia J Vargas¹, Alex Mira², Livia M A Tenuta³, Constanza E Fernández^{4

5}

Affiliations

¹ Master Program in Oral and Maxillofacial Health Sciences, Faculty of Dentistry, University of Talca, Talca, Chile.
² Department of Health and Genomics, Center for Advanced Research in Public Health, FISABIO Foundation, Valencia, Spain.
³ Department of Cariology, Restorative Sciences and Endodontics, School of Dentistry, University of Michigan, Ann Arbor, Michigan, USA.
⁴ Master Program in Oral and Maxillofacial Health Sciences, Faculty of Dentistry, University of Talca, Talca, Chile, cfernandez.go@gmail.com.
⁵ Cariology Unit, Department Oral Rehabilitation, Faculty of Dentistry, University of Talca, Talca, Chile, cfernandez.go@gmail.com.

PMID: 41284576
DOI: 10.1159/000549489

Abstract

Introduction: Potential dental health benefits, including pH buffering, have been demonstrated for nitrate in placebo-controlled studies when consumed one or several hours before sugar intake. However, its immediate local effect when co-administered with sugar is unclear. Our aim was to test the local effect of adding nitrate to a sugar rinse on human saliva acidification.

Methods: A double-blind, crossover study was conducted with three periods. In each period, 18 adults, equally distributed between men and women (n = 9 each), aged 25.4 ± 3.8 (mean ± SD), with normal salivary flow, rinsed for 2 min using 10 mL of one of the following rinses: spinach-only (blended spinach providing 8 m<sc>m</sc> nitrate), spinach+sucrose (blended spinach providing 8 m<sc>m</sc> nitrate + 20% sucrose), or sucrose-only (20% sucrose). Unstimulated saliva was collected at baseline and every 3 min up to 24 min. pH, lactate, nitrate, and nitrite were measured using Reflectoquant®. The effect of treatment and time was assessed using a linear mixed model (α = 0.05). Nitrate reduction capacity was determined in vitro using baseline saliva.

Results: All saliva samples demonstrated nitrate reduction activity. The lowest pH values were observed 6 min after rinsing, with all groups differing from each other: sucrose only (6.56 ± 0.38; mean ± SD), spinach+sucrose (6.83 ± 0.37), spinach only (7.15 ± 0.44, no pH drop). The pH returned to baseline values 12 min after the spinach+sucrose rinse, but not after the sucrose-only rinse at any time point. Nitrate and nitrite concentrations increased in saliva after using spinach-containing rinses, returning to their baseline levels after 6 min and 12 min. Lower lactate levels were detected after 12 min, suggesting proton consumption during nitrate metabolism in the spinach+sucrose group.

Conclusion: Adding a low dose of nitrate to a sucrose rinse limited sugar-induced salivary acidification in vivo, supporting the potential for topical nitrate strategies to reduce sugar acidogenicity.

Keywords: Acidogenicity; Local effect; Oral prebiotics; Salivary pH; Sucrose.