Substantive Fluoride Release from a New Fluoride Varnish Containing CXP™
The caries process requires bacteria, a susceptible host, an ideal environment, and time. Teeth are in a constant demineralization/remineralization cycle, fluoride in plaque and saliva help maintain an environment ideal for remineralization. In a study published in December 2015 in the journal Dentistry, the authors compare the quantity and rate of fluoride release from a newly marketed fluoride varnish with three other widely used varnishes.1
Though fluoride varnish is widely used as a caries prevention method in Canada and Europe, in the US the FDA has not approved fluoride varnishes for this purpose. This has not stopped many dental professionals from using it off label and with great success. The mechanism of action shows that fluoride deposited on the tooth’s surface is converted to fluorapatite. Further studies have shown the rate of dissolution of fluoride increases with a cariogenic challenge.
Many topical fluoride varnish manufacturers use additives they claim enhances the varnishes clinical efficacy. Some of the additives explored in this study include tri-calcium phosphate (TCP), amorphous calcium phosphate (ACP), and xylitol coated calcium phosphate (CXP™). The fluoride varnishes compared in the study were Duraphat→, Enamel Pro→, Vanish™, and Embrace™.
Duraphat→ (Colgate Palmolive, New York, NY) was the first commercially available fluoride varnish and is still widely used today. It contains either 2.26% fluoride ion or 5% NaF with no proprietary additives. Studies do confirm its efficacy with a reported 30% caries reduction rate.
Vanish™ (3M ESPE, St. Paul, MN) is reported to be the number one selling topical fluoride varnish in the United States. The formulation consists of 5% NaF and TCP as a proprietary additive. The manufacturer states, “TCP, unlike other calcium phosphate additives, is able to achieve more acid-resistant mineral nucleation through the addition of functionalized TCP.”
Enamel Pro→ varnish (Premiere Dental, Plymouth Meeting, PA) consists of 5% NaF and ACP as an additive. The manufacturers claim it is “able to deliver up to four times more fluoride than the leading varnish.” Previous studies have shown “a reduction in hydraulic conductance by 73% and semi-permanent occlusion of dentinal tubules.” This supports the second claim made by manufacturers that the varnish helps reduce dentinal sensitivity.
Embrace™ (Pulpdent Corporation, Watertown, MA) consists of 5% NaF with the additive CXP™. The manufacturer claims the varnish has “ten times more fluoride release over a 4-hour period than the leading varnish brand.” The manufacturers go on to claim the incorporation of CXP™ helps sustain the time-released properties. Reportedly, saliva dissolves the xylitol coating allowing the calcium and phosphate ions to react with the fluoride ions in a continuous manner.
The results of the study show Embrace™ released significantly greater cumulative amounts of fluoride after application when compared to the other varnishes. The claim made by the manufacturers of Embrace™ regarding the release of ten times more fluoride over a 4-hour period was examined. The results show fluoride release was approximately six, thirteen, and fifteen times higher than the other varnishes respectively, supporting the manufacturer’s claims.
The results of this study, which is also supported by several other studies show that fluoride release may be dependent on the type of resin carrier or additive. The authors conclude by stating, “In summary, Embrace™ had the greatest initial fluoride release, exceeding ten times that rate of a leading fluoride varnish (i.e., Vanish™) in a four-hour period. However, Embrace™ had the highest rate of fluoride depletion and the lowest substantivity of all varnishes tested. Vanish™ and Duraphat→ had the lowest initial fluoride release; however, they had greater substantivity than Embrace™.”
MilburnJL, Henrichs LE, Banfield RL, Stansell MJ, Vandewalle KS (2015) Substantive Fluoride Release from a New Fluoride Varnish Containing CXP™. Dentistry 5: 350. Doi: 10.4172/2161-1122.1000350.