Dental calculus forms through the mineralization of dental plaque, resulting in a variety of different crystalline forms (Sidaway 1978). First, new crystals form, that are composed of calcium and phosphate, which then grow and harden into calculus (Figures 18-19). The mineral content for supragingival and subgingival calculus is on average 37% and 58% by volume, respectively (Friskopp & Isacsson 1984). Supragingival calculus also contains bacterial debris and toxins as well as viable aerobic and anaerobic bacteria (Tan et al. 2004a; Tan et al. 2004b; White et al. 1997). This is of clinical significance as it can be a reservoir of pathogenic bacterial species (Tan et al. 2004b). Dental calculus is common in adults, and less common in children (Anerud et al. 1991).
Figure 18. Formation of dental calculus
In the 2-step and smooth texture formulas, the positively charged zinc ion (Zn2+) inhibits crystal growth by substituting for calcium in the crystal lattice of calcium phosphate (Figure 22). This interferes with the crystal formation and slows crystal growth (Segreto et al. 1991). Stannous fluoride also inhibits plaque formation, which is the structure on which calcium and phosphate precipitate.
Figure 19. Supragingival calculus
Figure 20. Hexametaphosphate molecule
Pyrophosphate helps to reduce dental calculus through a mineral chelating effect that inhibits plaque mineralization. It has a natural binding affinity for calcium ions. The anticalculus effect is due to adsorption and binding of the pyrophosphate to the tooth surface and to forming crystals of calcium phosphate in plaque, helping to inhibit the growth and maturation of calculus (White & Gerlach 2000; Rykke & Rolla 1990; Rolla et al. 1988). Sodium hexametaphosphate (Figure 20) is a longer-chain form of pyrophosphate, with more binding sites. It has a greater affinity for hydroxyapatite surfaces, and binds strongly to the tooth surface and the surface of developing calculus in plaque. (Figure 21 White & Gerlach 2000; Baig et al. 2002, Busscher et al. 2002)
Figure 21. Mechanism of action of sodium hexametaphosphate
In the 2-step and smooth texture formulas, the positively charged zinc ion (Zn2+) inhibits crystal growth by substituting for calcium in the crystal lattice of calcium phosphate (Figure 22). This interferes with the crystal formation and slows crystal growth (Segreto et al. 1991). Stannous fluoride also inhibits plaque formation, which is the structure on which calcium and phosphate precipitate.
Figure 22. Mechanism of action of zinc
The following study summaries represent a sample of research demonstrating the benefits of stabilized stannous fluoride dentifrice for calculus inhibition.
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):29-34.
Over a 6-month period a stabilized stannous fluoride dentifrice with sodium hexametaphosphate showed superior anticalculus efficacy compared with a marketed tartar control triclosan/copolymer control.
To assess the anticalculus efficacy of a 0.454% stabilized stannous fluoride dentifrice with sodium hexametaphosphate vs a positive control dentifrice.
Reference: Gerlach R, Farrell S, Anastasia MK, Amini P. J Dent Res 2016; 95 (Spec Iss A): Abstract 0093.
Figure 1. Tooth Stain Scores
* Baseline and post-prophy scores are means; Week 4 and Week 10 scores are adjusted means
** P<0.0005
Figure 2. Plaque Scores
* Baseline and post-prophy scores are means; Week 4 and Week 10 scores are adjusted means.
** P<0.0001
Figure 3. Calculus Scores
* Baseline and post-prophy scores are means; Week 4 and Week 10 scores are adjusted means.
** P<0.01
To assess the effectiveness of a daily 2-step dentifrice and gel system to prevent the formation of stain, calculus and plaque after a dental prophylaxis.
- Negative control - 0.76% sodium monofluorophosphate dentifrice (Colgate® Cavity Protection, Colgate-Palmolive)
- Daily 2-step dentifrice and gel system (Crest® PRO-HEALTH™ [HD]™) - Step 1, 0.454% stannous fluoride dentifrice; Step 2, 3% hydrogen peroxide whitening gel
Both groups brushed twice daily with a soft manual toothbrush (Oral-B® Indicator™, Procter & Gamble).
1 Lobene RR. Effect of dentifrices on tooth stain with controlled brushing. J Am Dent Assoc. 1968;77:849-855.
2 Volpe AR, Manhold JH, Hazen SP. In vivo calculus assessment. I. A method and its examiner reproducibility. J Periodontol. 1965;36:32-38.
3 Rustogi KN, Curtis JP, Volpe AR, Kemp JH, McCool JJ, Korn LR. Refinement of the modified Navy Plaque Index to increase efficiency in gumline and interproximal tooth areas. J Clin Dent. 1992;3 (Suppl C):C9-12.
Reference: Milleman JL, He T, Anastasia MK. J Dent Res 2017; 96 (Spec Iss A): Abstract 2816.
Figure. Calculus scores (VMI) per group.
N=78. *Significant difference between groups (P<0.05) using analysis of covariance.
To assess the calculus prevention benefit of an experimental stabilized SnF2 dentifrice relative to a negative control dentifrice.
- Experimental 0.454% stabilized SnF2 dentifrice (Crest® PRO-HEALTH™ Clean Mint [Smooth Formula], Procter & Gamble) with zinc to control calculus; or
- Negative control dentifrice (Colgate® Cavity Protection, Colgate-Palmolive).
Calculus build-up can lead to less efficient oral hygiene and tooth discoloration, as well as extending the time required for a dental prophylaxis. This research demonstrated a directional anti-calculus benefit for the SnF2 dentifrice relative to the control dentifrice in as early as 6 weeks. The relative benefit for the SnF2 dentifrice was even greater after 12 weeks of use. Dental professionals should consider recommending the SnF2 dentifrice for patients who form calculus, as it also improves gingival health and strengthens enamel.
In Vitro and In Vivo Evaluations of the Anti-calculus Effect of a Novel Stabilized Stannous Fluoride Dentifrice
Purpose: To evaluate the effect of a novel stannous fluoride dentifrice with zinc citrate on calculus inhibition using both in vitro and clinical models.
Anti-calculus Efficacy of a SnF2 Dentifrice in a Three-month Clinical
Purpose: The objective of the study was to assess the calculus prevention benefit of an experimental 0.454% Stannous Fluoride (SnF2) dentifrice relative to a negative control dentifrice.
Three Month Clinical Trial on the Anti-Calculus Effects of Two Dentifrices
Purpose: Supra-gingival dental calculus formation is a common problem for consumers. The present study was undertaken to evaluate the anti-calculus efficacy of a 0.454% Stannous Fluoride (SnF2)/sodium hexametaphosphate dentifrice relative to a marketed positive control dentifrice.
WHAT IS PLAQUE?
Dental plaque is a sticky, colorless or pale yellow film that is constantly forming on your teeth.
TARTAR ON TEETH
Teeth tartar, also called dental calculus, is a crusty deposit that can trap stains on the teeth and cause discoloration.