MI Paste

by Robert Margeas, DDS

In order for the caries process to begin, there must be a series of demineralization/remineralization events involving enamel and dentin. The process is initiated by the dissolution of tooth mineral (demineralization) by organic acids (lactic and acetic) produced by the action of plaque bacteria on dietary carbohydrates.1

If the demineralization process predominates, this carious lesion progresses to form a cavity. Remineralization (deposition of tooth mineral) can repair or arrest the caries lesion if caught in a timely manner. This can prevent cavity formation and the need to restore the tooth with a restoration.2 Numerous strategies have been focusing on minimizing bacterial growth, neutralizing the acids formed, and using remineralizing agents.

Professor Eric Reynolds and his research group at the University of Melbourne started investigating the anticariogenic properties of milk products in the early 1980s. They identified the role of casein phosphopeptides (CPP) in the stabilization and localization of amorphous calcium phosphate (ACP) at the tooth surface. More recently they have shown that CPP-ACP can repair early lesions by promoting subsurface remineralization.3

Cariogenic biofilms thrive in an acidic environment, which is partly created by food and beverage ingestion.4 An acidic environment also can develop if the saliva is of poor quality that is manifested as low pH.5

As we enter the early years of the 21st century, GC America is eager to contribute to the improvement of dental health by providing techniques, materials, instruments, equipment, and information for 1. identification of caries risk 2. prevention of caries, and 3. control of caries. The concept is called, the MI concept. MI is the abbreviation for “Minimum Intervention” dentistry. Recognizing decay at an early stage is critical to making MI dentistry work. GC has recently launched a new product in the U.S. called MI paste. This is a water based sugar free paste containing Recaldent CPP-ACP.

When MI paste is applied to tooth surfaces it binds to biofilms, plaque, bacteria, hydroxyapatite and surrounding soft tissues localizing bio-available calcium and phosphate. The Recaldent (CPP-ACP) technology releases the calcium and phosphate when a patient’s saliva is acid challenged by the normal digestive process. Under optimum circumstances, when fluoride, calcium, and phosphorus are available in the erupting tooth, the mix develops into a tooth that is resistant to all acid challenges.2 Fluoride also works better when it is used with calcium and phosphorus.6

Saliva enhances the effectiveness of CPP-ACP. The longer CPP-ACP in maintained in the mouth, the more effective the result. A delicate balance exists between health and disease. It involves acids and bacteria laden plaque competing with protective factors provided through normal salivary flow and good oral hygiene.

There are several indications for the use of Prospec (Professionally Specified) MI paste. It is used for post-bleaching sensitivity. The protocol is as follows: The paste is generously extruded into a custom bleaching tray after it has been rinsed out. The paste is allowed to come in contact with the teeth for three minutes. The patient does not rinse the paste away. Just expectorate what paste is left in the mouth. This will help seal any exposed dentinal tubules. A prophy cup application can be used following scaling and root planning to decrease post-operative sensitivity. In some situations MI paste can be used to reverse white spot lesions with orthodontic treatment and fluorosis. In theses defects, there are subsurface voids, which can be very effectively remineralized by application of MI paste, and this has been shown using optical and also radiographic tests at the University of Melbourne. Other clinical applications for MI paste include treating dentinal hypersensitivity, treatment of erosion and incipient carious lesions, caries prevention, and it promotes fluoride uptake.

MI paste comes in five tasty flavors — melon, mint, strawberry, tutti fruitti and vanilla. This new technology has a unique ability to deliver bio-available calcium and phosphate when they are needed most.

Dr. Margeas lectures internationally on the subject of aesthetic dentistry. He is board certified by the American board of operative dentistry. He is an adjunct professor at the University of Iowa, College of Dentistry and maintains a private practice in Des Moines, Iowa.

Oral Health welcomes this original article. References available upon request.


1.Loesche WJ: Role of Streptococcus mutans in human dental decay. Microbiol Rev 50:353-380, 1986.

2.Anusavice KJ: Efficacy of non-surgical management of the initial caries lesion. J Dent Educ 61:895-905, 1997.

3.Reynolds EC: Remineralization of enamel subsurface lesions by casein phosphopeptide-stabilized calcium phosphate solutions. J Dent Res 76:1587-1595, 1997.

4.Bradshaw DJ, Marsh PD, Hodgson RJ, et al: Effects of glucose and fluoride on competition and metabolism within in vitro dental bacterial communities and biofilms. Caries Res. 2002;36(2):81-86.

5.Sanchez CA, Fernandez D, Preliasco MV: Salivary pH changes during soft drink consumption in children. Int J Paediatr Dent. 2003;13(4):251-257.

6.Featherstone JD: The science and practice of caries prevention. J Am Dent Assoc. 2000;131(7):887-889.