Assessment of tubule occlusion properties of an experimental stannous fluoride toothpaste: A randomised clinical in situ study

Abstract

Keywords:Crossover Dentine hypersensitivity Dentinal tubule occlusion in situ model Stannous fluoride Toothpaste A B S T R A C TObjectives: To evaluate the ability of a modified in situ model to differentiate dentinal tubule occlusion properties of toothpaste formulations over 10 days of treatment.Methods: This was a single-centre, three-treatment period, crossover, randomised, single-blind study with healthy participants wearing two lower oral appliances, each retaining four dentine samples, for 10 treatment days during each period of the study. Samples were power-brushed ex vivo twice on each treatment day with a Test toothpaste containing 0.454% stannous fluoride, a Control fluoride toothpaste containing 0.76% sodium monofluorophosphate, or mineral water. Dentine samples were subjected to in situ acid challenge (orange juice) on Days 9 and 10. Scanning electron microscopy images obtained at baseline and after 1, 4, 8 and 10 days of treatment were graded for degree of surface coverage by four calibrated examiners; the primary study endpoint was Day 8. Results: After 4, but not 8, days' treatment, the degree of tubule occlusion increased in the dentine samples treated with the Test or Control toothpastes compared with the water-treated samples (p < 0.01 and p < 0.05, respectively). Following the acid challenge (Day 10), there was a statistically significantly greater degree of occlusion in the Test toothpaste-treated dentine samples compared with those treated with water (p < 0.01). No other comparisons were statistically significant. All study treatments were generally well-tolerated. Conclusions: This modified in situ model was unable to demonstrate statistically significant between-treatment differences in dentinal tubule occlusion after 8 days. Conversely, there are recognised developments that could be made to better identify product differences. Clinicaltrials.gov: NCT02768194. Clinical significance: Dentine hypersensitivity can be managed through brushing with stannous fluoride toothpastes, which occlude patent dentine tubules. Clinical studies measure pain but in situ models are needed to demonstrate occlusion intra-orally. However, this study did not demonstrate superior occlusion with stannous toothpaste; further methodological development is required to investigate its mode of action.

Measurement of eroded dentine tubule patency and roughness following novel dab-on or brushing abrasion

“…Occlusion might occur either at or below the dentine surface ('sub-surface' occlusion) [11]. Stannous fluoride (SnF2) has been shown to occlude dentine tubules [12] and offer resistance to acid challenge [13]. It may offer benefits in reducing erosive dentine wear [14].…”

Stannous Fluoride Effects on Enamel: A Systematic Review

“…Zero et al [ 42 ] showed that all 1400–1450 ppm F dentifrices provide better remineralization than placebo, except for the SnF 2 group. According to West et al [ 43 ] there is a high grade of tubule occlusion in the toothpaste containing 0.454% stannous fluoride and in the fluoride toothpaste containing 0.76% sodium monofluorophosphate brushed dentine samples. There are no statistical differences between the first and second group of study.…”

“…Huysmans et al [ 56 ] with their SEM analysis concluded that SnF 2 toothpaste could reduce erosive tooth wear in situ. West et al [ 43 ] concluded that there are no differences in tubule occlusion capability between toothpaste containing 0.454% stannous fluoride and fluoride toothpaste containing 0.76% sodium monofluorophosphate. However, following the acid challenge, there was a statistically significantly greater degree of occlusion in the stannous fluoride toothpaste.…”

The ability of a potassium oxalate gel strip to occlude human dentine tubules; a Novel in vitro: In situ Study

“…Other in vitro studies with no external oral influences such as oral debris within the model found that imaging the surface did not reveal a complete coating on the surface of the dentine and tubules appeared occluded in the depth of the tubule rather than at the surface [33]. It is therefore important to investigate the tubule occlusion in the depth of the tubule for this agent as opposed to the surface alone in line with the mode of action of a number of other occluding agents, as this will not reveal the potential occlusion benefit for potassium oxalate [34].…”