Dental erosion is prevalent in children and adults globally, with some researchers finding it present in approximately half of adolescents (Al-Dlaigan et al. 2001; McGuire et al. 2009). Estimated prevalence in some locations can be found in Figure 6..
Dental erosion occurs primarily due to the excessive presence of non-bacterial extrinsic acids (especially dietary acids such as acidic drinks), as well as intrinsic gastric acid associated with gastroesophageal reflux disease (GERD) and bulimia (Moazzez et al. 2004; Bouqot & Seime 1997). Dental erosion involves the demineralization and softening of the tooth surface, which once softened, is highly susceptible to abrasion and attrition (Figure 7). A diagnosis of erosion can be made based on the pattern of surface loss of enamel and/or dentin (Figures 8a,b)
Figure 7. Demineralization associated with dental erosion
Figure 8a. Generalized erosion
Courtesy of Prof. Ian Meyers
Figure 8b. Severe palatal erosion and loss of tooth structure.
Courtesy of Prof. Ian Meyers
Unlike dental caries where demineralization is initially mainly subsurface and is also reversible in its early stages, dental erosion involves repeated demineralization of the surface with subsequent surface loss and this process is irreversible (Figures 9a, b).
Figure 9a. Dental caries process
Reversible
Enamel crystals are weakened, but remain structurally intact. The early caries process is reversible
Figure 9b. Dental erosion process
Irreversible
Enamel crystals are damaged structurally from the surface down into the tooth. The erosive process is irreversible
The deposition of stannous ions at the tooth surface helps protect it against dental erosion (Faller & Eversole 2014):
A recent in vitro study compared the ability of various fluoride toothpastes to form a protective barrier layer (Faller & Eversole 2014). The toothpastes evaluated included 1,100 ppm stannous fluoride, 1,100 ppm sodium fluoride, 1,000 ppm sodium monofluorophosphate and 1,400 ppm amine fluoride. The study involved exposing etched samples to toothpaste-saliva slurries, rinsing them, and then exposing them to 2% alizarin Red-S. Dye deposition was assessed using a 5-point scale, with 0 being no dye deposition and 4 being complete dye coverage. A low score indicates a barrier layer is present, preventing the deposition of dye. The stannous fluoride toothpaste had the lowest score, 0.25. At the other extreme, amine fluoride resulted in a score of 3.7 (Figure 10). This in vitro test confirmed the ability of stannous to form a protective barrier layer, and demonstrated that stannous fluoride is a preferred fluoride for delivering an enamel protection benefit via a barrier mechanism to erosive acids.
Figure 10. Degree of dye deposition on enamel samples following exposure to toothpaste slurry followed by dye
* Average deposition of stain (based on the 5-point scale)
Other in vitro tests have also demonstrated the superior protective effect of stannous fluoride-treated enamel slabs in comparison to sodium fluoride-treated enamel slabs during an erosive challenge (Figure 11; Faller 2012). Exposure to dietary acid in an erosion cycling model resulted in surface demineralization and surface loss for the slabs treated with sodium fluoride toothpaste slurry while minimal demineralization or surface loss occurred with the slabs treated with stannous fluoride toothpaste slurry.
Figure 11. Stannous fluoride vs. sodium fluoride in in vitro treated enamel slabs
The following study summaries represent a sample of research demonstrating the benefits of stabilized stannous fluoride dentifrice for protection against acid erosion.
In addition, an independent consensus statement by the European Federation of Conservative Dentistry found “oral hygiene products, such as toothpastes or mouth rinses, containing stannous fluoride or stannous chloride have the potential to slow the progression of erosive tooth wear.” The authors found data are limited for other products. (Carvalho et al. 2015)
Reference: Hooper SM, Newcombe RG, Faller R, Eversole S, Addy M, West NX. J Dent. 2007 Jun;35(6):476-81. Epub 2007 Feb 27
The results of this study provide further support for tooth brushing before meals. Results further suggest the stannous fluoride dentifrice could be used to provide significant erosion protection in susceptible patients versus that provided by conventional fluoride products.
Consumption of soft drinks, fruit juices and sport drinks has increased dramatically in the UK, the US, and elsewhere. Previous studies have demonstrated the erosive nature of these acidic soft drinks. The objective of this study was to determine the protective effects of experimental stannous fluoride-based toothpaste, containing sodium hexametaphosphate, against an erosive challenge (orange juice) on tooth enamel.
There was significantly more erosive damage on the specimens exposed to the benchmark toothpaste (NaF) and negative control (water) compared to the test stannous fluoride toothpaste in both the in situ (Figure 1) and in vitro (Figure 2) studies.
Figure 1. In Situ Loss of Material*
Figure 2. In Vitro Loss of Material*
* mean value based on duplicate determinations of two enamel specimens
Reference: Faller RV, Eversole SL, Tzeghai G. J Dent Res. 2009;88 (Spec Iss A): Abstract 3368.
Dentifrices with RDA< 250 are considered safe for daily use. Some researchers believe products with low RDA may be less aggressive on erosively softened enamel. Others believe that once softened, erosively challenged enamel will be removed by any friction, even by the tongue. This research was conducted to determine the primary driver of enamel protection benefits: is abrasivity or fluoride (F) salt the more important factor?
Table. Results
Figure Average % Reduction in Total Mineral Loss*
* (vs. NaF product)
Reference: XY Zhao1, T He2, Y He2, C Cheng2, HJ Chen2.
1Fourth Military Medical University, Xi’an, PR China; 2Procter & Gamble.
The experimental stabilized stannous fluoride (SnF2) dentifrice provided 26.9% greater erosion protection relative to the control dentifrice at Day 10 (P<0.03).
Figure. Treatment comparison at Day 10: Median Change in Enamel (μm)
*Lussi A. Int Dent J 2014; 64 (Suppl 1): 2-3.
To compare the enamel protection efficacy of a stabilized stannous fluoride dentifrice and a marketed control dentifrice in a 10-day in situ erosion model.
Stabilized SnF2 dentifrice has been shown to provide significantly greater protection from acid erosion compared to other types of fluoride dentifrice.* In this trial, a novel stabilized stannous fluoride dentifrice showed a significant anti-erosion benefit over a sodium fluoride/potassium nitrate dentifrice which is marketed for protecting enamel against acid erosion. Dental professionals should consider recommending this SnF2 dentifrice for its high level of protection against acid erosion as well as its benefits for reduction of gingivitis and plaque.
*Lussi A. Int Dent J 2014; 64 (Suppl 1): 2-3.
Randomized in situ clinical trial evaluating erosion protection efficacy of a 0.454% stannous fluoride dentifrice
Purpose: To assess the protective effects of a 0.454% stabilized stannous fluoride dentifrice and a marketed triclosan dentifrice against enamel erosion in a 10-day in situ model.
Determining the AntiErosive Effect of a Stannous Fluoride Containing Paste
Purpose: To determine the enamel protection efficacy of a stannous fluoride containing dentifrice compared to a conventional sodium fluoride containing dentifrice using a 10 day in situ erosion model.
SENSITIVE TEETH – CAUSES AND TREATMENT
Sensitive teeth (dentinal hypersensitivity) can occur when gums pull away from your teeth at the gumline exposing the dentin layer of your tooth.
In addition to the onset of smear layer formation, the durability of the tubule occlusions also impacts the effectiveness of the anti-hypersensitivity agent. Stabilized stannous fluoride dentifrice forms a smear layer that is resistant to both daily mechanical and acid challenges. Figure 15 compares a stabilized stannous fluoride dentifrice to two other anti-hypersensitivity toothpastes which also act by a tubule occlusion mechanism. The smear layer of the stabilized stannous fluoride dentifrice is more resistant to a dietary acid challenge than that of either of the other products (Zsiska et al. 2011).
Early treatments using solutions and later gels demonstrated the desensitizing effect of stannous fluoride. The dentinal tubules are occluded by precipitated stannous salts, inhibiting fluid movement within the tubules and thereby preventing nerve stimulation and pain (Figures 13, 14; Miller et al. 1994; Thrash et al. 1995).
Figure 13. Dentinal tubule occlusion: Note the effective occlusion of dentinal tubules with stabilized stannous fluoride dentifrice (SEM x2000)
Figure 14. Pre-and post-brushing SEMs: pre-and post-treatment with open and occluded dentinal tubules Courtesy of Cosmetics & Toiletries
Figure 15. Relative dentinal tubule occlusion for stabilized stannous fluoride dentifrice versus two other anti-hypersensitivity dentifrices after treatment, mechanical agitation, and one minute acid exposure.
The following study summaries represent a sample of research demonstrating the benefits of stabilized stannous fluoride dentifrice for the reduction of hypersensitivity.
Reference: Schiff T, He T, Sagel L, et al. J Contemp Dent Pract. 2006;7(2):1-8.
Crest® PRO-HEALTH™ provided statistically significant reductions in dentinal hypersensitivity at 4 and 8 weeks compared to the sodium fluoride control dentifrice.
To compare the efficacy of Crest® PRO-HEALTH™ vs a negative control dentifrice in the reduction of dentinal hypersensitivity over an 8-week period.
Lower Schiff Air Index scores indicate less tooth sensitivity
Full text available in the Research Database at www.dentalcare.com
Reference: Schiff T, Saletta L, Baker RA, et al. Compend Contin Educ Dent. 2005;26(9 suppl 1):35-40.
Crest® PRO-HEALTH™ showed a clinically and statistically significant decrease in hypersensitivity compared to a negative control dentifrice.
To evaluate the desensitizing properties of Crest® PRO-HEALTH™ compared to a negative control dentifrice.
Lower Schiff Air Index scores indicate less tooth sensitivity
Reference: He, ML Barker, Qaqish J, et al. J Clin Dent 2011; 22: 46-50.
Figure 1. Thermal Schiff Air Index Adjusted Mean Scores
(Lower score indicates less sensitivity)
Figure 2. Thermal Air Visual Analog Scale Adjusted Mean Scores
(Lower score indicates less sensitivity)
Figure 2. Mean tactile sensitivity scores at Baseline and Week 2. N=69
To evaluate the efficacy of a SnF2 dentifrice in the reduction of dentinal hypersensitivity after immediate use, 3 days and 2 weeks of use as compared to a negative control dentifrice.
Reference: Gerlach RW, Underwood J, Miner M. Data on file, 2016.
Figure 1. Mean thermal sensitivity scores at Baseline and Week 2. N=69
Figure 2. Mean tactile sensitivity scores at Baseline and Week 2. N=69
To evaluate changes in dentinal hypersensitivity in response to using a two-step stannous fluoride dentifrice and whitening gel system relative to a positive control potassium nitrate sensitivity toothpaste.
- Crest® PRO-HEALTH™ [HD]™: Step 1 is a 0.454% stannous fluoride dentifrice; Step 2 is a 3% is a hydrogen peroxide whitening gel (Procter & Gamble)
- Positive Control: Sensodyne Extra Whitening with sodium fluoride and 5% potassium nitrate (GlaxoSmithKline)
- Both groups used a soft, manual toothbrush (Oral-B® Indicator®, Procter & Gamble)
Dentinal hypersensitivity is defined as a brief, sharp pain from the exposure of dentin to thermal, tactile, osmotic, chemical, or evaporative stimuli, which cannot be attributed to any other form of dental defect or disease. Patients commonly manage dentinal hypersensitivity by using a dentifrice containing a desensitizing agent, such as potassium nitrate or stannous fluoride. Potassium nitrate is reported to reduce sensitivity by interfering with the transmission of pain signals. Stannous fluoride has been shown to occlude open dentin tubules, reducing fluid flow in response to stimuli and thereby reducing pain.
Stabilized stannous fluoride dentifrice has been shown to provide superior relief from thermal and tactile dentinal hypersensitivity versus negative and positive controls.3 Consistent with published literature, the 2-step stannous fluoride dentifrice and whitening gel system provided superior sensitivity relief compared to a marketed potassium nitrate whitening dentifrice.* This 2-step system has also been shown to provide gingivitis reductions comparable to chlorhexidine* with significant whitening benefits.4,5 Thus, dental professionals can recommend this system to patients with dentinal hypersensitivity with confidence they will not only experience relief from sensitivity, but also improvements in gingival health and tooth whitening.
* via Step 1 stannous fluoride dentifrice
1 Schiff T, et al. J Clin Dent 1994;5 Spec No: 87-92.
2 Schiff T, et al. J Contemp Dent Pract 2006;May;(7)2:001-008.
3 Walters P. Dentinal Hypersensitivity: A Review. Updated Dec 2014; dentalcare.com CE Course #200.
4 Gerlach RW, et al. J Dent Res 2015;94 (Spec Iss A): Abstract 293.
5 Garcia-Godoy, C et al. J Dent Res 2016; 96 (Spec Iss A): Abstract 92.
Bioavailable gluconate chelated stannous fluoride toothpaste meta-analyses: Effects on dentine hypersensitivity and enamel erosion
Purpose: To compare the effect of bioavailable gluconate-chelated stannous fluoride (SnF2) toothpaste with control toothpastes for treatment of dentine hypersensitivity (DH) and enamel erosion.
A Randomized Clinical Trial to Assess the Desensitizing Benefit of a Stabilized Stannous Fluoride Dentifrice
Purpose: To assess the desensitizing efficacy of a stabilized stannous fluoride dentifrice versus a sodium fluoride negative control.
Fast onset sensitivity relief of a 0.454% stannous fluoride dentifrice
Purpose: To evaluate the efficacy of a stannous fluoride dentifrice as compared to a negative control dentifrice in the reduction of dentinal hypersensitivity after immediate use, and after three days and two weeks of use.
A Clinical Assessment of the Efficacy of a Stannous-Containing Sodium Fluoride Dentifrice on Dentinal Hypersensitivity
Purpose: To measure the desensitizing benefits of an experimental stannous-containing sodium fluoride dentifrice versus a regular sodium fluoride negative control.