Effect of the order of application of toothpaste and solutions containing fluoride and stannous on the progression of erosive wear on bovine enamel and dentin - an in situ study

Author(s)

Alana Cristina Machado

• Document type: Doctoral Thesis
• Press: São Paulo.
• Institution: Universidade de São Paulo (USP). Faculdade de Odontologia (FO/SDO)
• Defense date: 2021-03-05

Examining board members

Taís Scaramucci Forlin; Sávio José Cardoso Bezerra; Daniela Rios Honório; Fausto Medeiros Mendes

• Advisor: Taís Scaramucci Forlin

Abstract

Considering that the eroded enamel is more susceptible to be wear off by toothbrushing abrasion, and that fluoride, or the combination between fluoride and stannous, can induce precipitates that are relatively resistant to toothbrushing, the objective of this in situ study was to evaluate the impact of the application of a F- /Sn2+ containing mouthrinse before or after toothbrushing with a F- /Sn2+/chitosan toothpaste on the progression of erosion/abrasion on enamel and dentin. This study had 2 experimental factors, substrates and treatments. Two hundred and twenty-five enamel and dentin specimens (with 3mmx3mmx1.5mm) were cut from bovine incisors, flattened, polished, and randomly allocated into 5 experimental groups (n=45 from each substrate), according to the following treatments: Control (toothbrushing without toothpaste), E (toothbrushing with toothpaste), E+B (toothbrushing with toothpaste and rinse with mouthrinse), B+E (rinse with mouthrinse and toothbrushing with toothpaste), and B (rinse with mouthrinse). Fifteen subjects used removable mandibular appliances containing 3 enamel and 3 dentin specimens, which were subjected to the following erosion-abrasion cycling with 5 phases according to the treatment: 60 min salivary pellicle formation, followed by 5 min extraoral erosion with 1% citric acid (4x/day for 5 days). Treatments were performed in situ after first and last erosive challenges with rinse (10 ml; 30 s) and/or toothbrushing with/without toothpaste (with electric toothbrush; 5 s per specimen; total 2 min contact with slurry). Surface loss (SL) was evaluated with an optical profilometer. Data were analyzed by two-way repeated measures ANOVA and Tukey tests (? = 0.05). There was no interaction between the factors, thus the Control showed the highest SL (mean ± SD for enamel: 24.58 ± 11.32; dentin: 32.32 ± 10.10; all µm). Rinsing alone resulted in significantly lower SL value (enamel: 8.30 ± 4.96; dentin: 16.15 ± 8.29) compared with arms that applied toothpaste, except Brushing+Rinsing. None of the arms that underwent toothbrushing with the toothpaste differed from each other (p>0.05). Dentin specimens showed significantly higher SL values than enamel (p<0.001). We can conclude that the order of treatment applications has no influence on their anti-erosive effect; however, toothbrushing with F- /Sn2+/chitosan toothpaste reduce enamel surface loss. Additional rinsing with F- /Sn2+ mouthrinse do not offer improved protection. (AU)

• FAPESP's process: 17/24714-3 - Effect of the order of application of dentifrices and solutions containing fluorides and tin in the progression of erosive wear on enamel and bovine dentin - in situ study
• Grantee: Alana Cristina Machado
• Support Opportunities: Scholarships in Brazil - Doctorate