Why Amorphous Calcium Phosphate
Makes a Difference for Enhancing Remineralization and Reducing Sensitivity
What is ACP? | ACP Benefits | ACP's role in tooth whitening
What is ACP?
Chemical Makeup
ACP is an abbreviation for Amorphous Calcium Phosphate. ACP is created when dissolved calcium ions and phosphate ions react to form a non-crystalline insoluble salt. Due to the reactive nature of the chemicals involved, the calcium and phosphate must be stored separately until they are applied to the tooth surface.
How ACP Works
Tooth demineralization from acid results in dulling, loss of tooth luster, and a higher susceptibility to caries. The oral environment can naturally rebuild enamel, through a process called remineralization, to some extent on its own, but the extent of remineralization is controlled by pH and the amount and availability of calcium and phosphate ions present in the mouth. Remineralization can easily be reversed in an under-saturated environment.
The natural rebuilding of enamel is a slow kinetic reaction which can be rapidly sped up by the addition of ACP-forming components into the oral environment. Amorphous Calcium Phosphate (ACP) is the reacted complex of calcium and phosphate ions that precipitate and can grow on tooth surfaces in the oral environment.
These initial ACP complexes are thermodynamically unstable under the conditions normally prevalent in the oral environment; pH, temperature, etc. Over time, these unstable compounds will undergo further reactions as well as phase transformation into other more stable forms of calcium phosphate. The precise path of the complex transformation is not fully understood, but the final form has been shown to be hydroxyapatite: a large constituent of the normal, mineralized structure of healthy teeth. In practice, introducing ACP onto a tooth surface will lead to rapid deposition of a new coating of hydroxyapatite over the original tooth surface.1,2
At normal oral pH and temperature, the addition of ACP-components to the salivary system can cause the hydrolysis of ACP into apatite within a few minutes, which is roughly 20,000 times faster than normal, physiologic formation of apatite.3 Besides adding to the external resistance of the teeth by building a barrier of acid resistant hydroxyapatite, ACP also biases the remineralization-demineralization equilibrium by releasing essential ions that favor remineralization by increasing the degree of saturation with respect to hydroxyapatite. Furthermore, calcium and phosphates can bind with other ions such as fluoride, and other proteins in saliva, to form complexes that can be stored in plaque and saliva, ready to release calcium, fluoride, and phosphate ions in response to acid challenges.4
ACP Benefits
Rebuilds Enamel
The deposition of hydroxyapatite onto teeth rebuilds enamel and restores luster through a process called remineralization. Preliminary research by Flaitz & Hicks at the University of Texas, Houston, showed that,"The addition of calcium phosphate to whitening agents reduces the susceptibility of enamel to "in-vitro" lesion initiation and progression."5
Effective Desensitizer
ACP mimics the natural desensitizing process by eliminating the source of sensitivity by plugging dentinal tubules with calcium phosphate, the tooth mineral. This is similar to the process of sclerosis, where salivary mineral precipitates slowly over time in these tubules and reduces sensitivity. ACP simply speeds this process considerably with the same mineral at much higher concentrations.
ACP has been clinically shown to dramatically reduce dentinal hypersensitivity by occluding dentinal tubules.6
Improved Appearance -
Restores Enamel Luster
ACP has been clinically shown to improve the smoothness and luster of teeth8 by filling superficial tooth defects and improving the overall smoothness and luster of patients' smiles.3
Lasting Results
In clinical studies, patients who used a take-home dental tooth whitener containing ACP experienced less fadeback six months after treatment compared to patients who used an identical take-home whitener without ACP.9
ACP's Role in Tooth Whitening
Rebuilds Enamel
The deposition of hydroxyapatite onto teeth rebuilds enamel and restores luster through a process called remineralization. Preliminary research shows that remineralization can both strengthen teeth10,11 and reduce the susceptibility of enamel to in vitro lesion initiation and progression.5
Prevents Sensitivity
Clinical tests comparing a leading whitening product used in two groups, one with ACP, the other without, showed that patients who used the same whitener containing ACP reported 30% less sensitivity, with twice as many patients experiencing zero sensitivity.7
Improves Appearance
Tooth whitener with ACP also adds to the improved cosmetic appearance of teeth by restoring enamel luster to create a smoother, glossier appearance. Studies also show the patients who used a tooth whitener with ACP experienced less fadeback to their original tooth color after six months.8
ACP is patented technology exclusively licensed by the ADA Foundation.
Endnotes
- 1 Tung, M.S., Eichmiller, F.C. Amorphous Calcium Phosphate for tooth mineralization. Compend Contin Educ Dent, Vol 25, No 9 Suppl 1, Sep 2004, pp 9-13. Journal Code 9600713, Journal Subset MEDJSD, ISSN 1548-8578. Corporate Author: American Dental Association Foundation.
- 2 M. Markovic, B.O. Fowler And M.S. Tung. Preparation and Comprehensive Characterization of a Calcium Hydroxyapatite Reference Material. Journal of Research of the National Institute of Standards and Technology, Volume 109, Number 6, November-December 2004.
- 3 Tung, M.S., Eichmiller, F.C. Amorphous Calcium Phosphate for tooth mineralization. Compend Contin Educ Dent, Vol 25, No 9 Suppl 1, Sep 2004, pp 9-13. Journal Code 9600713, Journal Subset MEDJSD, ISSN 1548-8578. Corporate Author: American Dental Association Foundation.
- 4 Grant LP, Thompson A, Tanzer JM. Caries inhibition in rats by a remineralizing toothpaste. Journal of Clinical Dentistry. 1999;10(1 spec no):30-33.
- 5 5 Flaitz C, Hicks J. Whitening Agent Effects on Enamel Caries Formation and Progression. IADR Unpublished Abstract #73739.
- 6 M. Cherng, S. Takagi And L.C. Chow. Reduction in Dentin Permeability Using a Calcium Phosphate Slurry. Journal of Dental Research 83 (Special Issue A); IADR CD-ROM Abstract No. 0119, 2004.
- 7 Giniger, MacDonald, Ziemba, Felix. The Clinical Performance of Professionally Dispensed Bleaching Gel with Added Amorphous Calcium Phosphate. Jada Vol. 136, March 2005.
- 8 Giniger M, Spaid M, Felix M, MacDonald J, Ziemba S. Tooth Surface Enhancement by a 16% Carbamide Peroxide Take-Home Bleaching Gel Containing ACP. Journal of Dental Research. 84(Spec Issue A): 1793,2005.
- 9 Giniger M, Spaid M, Felix H, MacDonald J. A 180-Day Clinical Investigation of the Tooth Whitening Efficacy of a Bleaching Gel with Added Amorphous Calcium Phosphate. Journal of Clinical Dentistry, Volume XVI, No. 1, 2005.
- 10 Schemehorn BR, Orban JC, Wood GD, et al. Remineralization by fluoride enhanced with calcium and phosphate ingredients. J Clin Dent. 1999;10(1 spec no):13-16.
- 11 Litkowski, Quinlan, Ross, Church & Dwight. Intraoral Evaluation of Mineralization of Cosmetic Defects by a Toothpaste Containing Calcium, Fluoride, and Sodium Bicarbonate. Compendium Vol. 25, No. 9 (Suppl 1) September 2004.
