Calcium phosphate technology in dentistry.......

Calcium phosphate technology products treat demineralization, dental hypersensitivity

Mar 18, 2011

By Terri Tilliss, RDH, BS, MS, MA, PhD

Products utilizing calcium phosphate technology are often administered and recommended to treat both demineralization and dentinal hypersensitivity. This technology was developed over 20 years ago in an ADA-associated research center.
The rationale behind its development was to provide the same minerals found in hydroxyapatite to speed up remineralization in the presence of fluoride. The concept is that by rapidly depositing additional mineral onto the tooth, surface defects would remineralize. It has been extrapolated that these same minerals would also block exposed dentinal tubules and improve dentinal hypersensitivity.
To evaluate whether calcium phosphate containing products can remineralize tooth structure and/or treat dentinal hypersensitivity, it is useful to utilize an evidence-based assessment. The evidence-based process is a systematic approach for reviewing the large volume of health care literature.
This approach integrates: 1) clinically relevant scientific evidence relating to the patient’s oral and medical condition and history, 2) clinical expertise, 3) the patient’s treatment needs and preferences.(1)
With calcium phosphate products, there has been an emphasis on the 2nd and 3rd components of this triad, without enough emphasis on accumulating the best scientific evidence. Most studies that support utilizing these products for caries control have been conducted with animals, had an in-vitro design (laboratory-based), or were conducting utilizing in-situ caries models, and nearly all have looked at remineralization, not desensitization.
These types of research alone do not constitute "best evidence." This term refers to information obtained from randomized and non-randomized controlled clinical trials, cohort studies, case-control studies, crossover studies, cross-sectional studies, case studies, and the consensus opinion of experts in appropriate fields of research or clinical practice.
These types of research still need to be conducted with calcium phosphate products. An additional concern is that many of completed studies have been supported by, promoted by, or conducted by those with a vested interest in the outcomes and commercial products.
Our understanding of plaque biofilm provides a striking example of why in-vivo research is critical. We learned that bacteria function very differently in the laboratory compared to when they live in the oral cavity. Clinical studies elucidated the critical concept of biofilm, a community of bacterial microcolonies, an extracellular slime layer, and fluid channels; this was not fully evident using in-vitro or in-situ models.
Calcium phosphate products have been introduced to the dental profession and marketed to the public for caries control without a body of valid and reliable clinical trials. The products are advertised as beneficial for all patients with caries and sensitivity. However, experts have stated that these products are most likely to provide remineralization benefits for those with poor salivary flow and consequent deficient calcium phosphate levels.(2)
For people with normal salivary flow and composition, there is already adequate calcium and phosphate; adding more does not provide additional benefits. An article reviewing caries management with calcium phosphate agents concurs that patients with salivary hypofunction including low flow, low pH, and poor buffering capacity may benefit from the use of these agents, but that for those with normal saliva, there are already sufficient calcium and phosphate ions present.(3)
Although clinical studies have suggested desensitization benefits of calcium phosphate products (4,5), there is a need for more trials before "best evidence" is available. Experts have explained that remineralization products and the biofilm are linked to both sensitivity problems and solutions,(6) but that the mechanisms involved in remineralization and sensitivity are very different and the outcomes may differ7.
The successful sales of calcium phosphate products been based largely on the 2nd and 3rd parts of the evidence-based triad; however, both clinical expertise and patient preference can be easily biased by the idea or suggestion that a product "should" work.
Evidence-based dentistry requires that scientific evidence be combined with views of the clinician and patients. Additional in-vivo clinical trials are requisite to establish the clinical relevance of this calcium phosphate technology for controlling caries and dentinal sensitivity.
References
1. American Dental Association Center for Evidence-Based Dentistry. Accessed at ebd.ada.org/about.aspx, 3/8/11.
2. Chow L, Wefel JS. The dynamics of de-and remineralization. Dimensions Dent Hyg 2009; 7(2):42-6.
3. Hurlbutt M. Caries management with calcium phosphate. Dimensions Dent Hyg 2010; 8:40,42,44-46.
4. Tung Ms, Eichmiller FX. Dental applications of amorphous calcium phosphates. J Clin Dent 1999; 10 (special number):1-6.
5. Giniger M, Macdonald J, Siemba S, Felix H. The clinical performance of professionally dispensed bleaching gel with added amorphous calcium phosphate. JADA 2005; 136:383-391.
6. Wolff MS. Dentin hypersensitivity, the biofilm, and remineralization: what is the connection? Adv Dent Res 2009; 21:21-24.
7. Pitts NB, Wefel JS. Remineralization/desensitization: What is known? What is in the future? Adv Dent Res 2009; 21:83-86.
Schematic is from The ADA Center for Evidence-Based Dentistry. Accessed at: ebd.ada.org/About.aspx, 3/9/11