Inside Dentistry
July 2017
Volume 13, Issue 7

Delivery of Fluoride Solutions to Proximal Tooth Surfaces

Part I: Caries prevention with fluoride varnish and gel

Theodore P. Croll, DDS | Joel H. Berg, DDS, MS

The development of proximal decalcification and caries lesions can be especially distressing to patients, parents, orthodontists, and other dentists who provide orthodontic services. Bonded orthodontic hardware makes it difficult to diagnose proximal decalcification with bitewing images or other radiographs (Figure 1), and even with transillumination (Figure 2) and other methods, such proximal damage can still occur undetected. In addition, the development of decalcification and caries lesions on the distal surfaces of primary second molars and the contacting mesial surfaces of permanent first molars due to poor flossing compliance is regularly diagnosed by dentists.

Although protocols for more frequent professional applications of topical fluoride solutions and at-home daily exposure of topical fluoride are available,1 this brief report offers recommendations for more exacting delivery of preventive fluoride solutions into interproximal regions to assure that proximal dental surfaces benefit from the maximum exposure and uptake of fluoride into the enamel, especially among young patients wearing fixed orthodontic appliances. These recommendations include methods for easy, periodic “in-office” proximal delivery of fluoride solutions and daily saturation of proximal sites with a non-prescription stannous fluoride gel.

In-Office Proximal Fluoride Delivery

GUM® Soft-Picks® (Sunstar Americas, Inc.) and TePe EASYPICK™ (TePe USA, Elevate Oral Care) interdental picks are not only excellent for cleaning between contacting teeth, but their irregular side surfaces also carry fluoride solutions into interproximal sites and agitate the fluids once inserted (Figure 3).

The dentist chooses the fluoride solution (eg, a 2.5% (11,300 ppm) fluoride varnish with proven high fluoride ion uptake by enamel) based on his or her own preference (Figure 4). After routine prophylaxis, flossing, and fluoride application, the interdental pick is dipped in the fluoride solution and inserted interproximally. In patients with bonded orthodontic hardware, the tip is inserted both below and above the arch wire (Figure 5 and Figure 6). The pick can also be inserted from the lingual direction to assure complete saturation of the site (Figure 7). These fluoride varnish applications can be performed by either the dentist or auxiliary staff.

Based on a patient’s susceptibility to caries, the frequency of in-office interproximal fluoride delivery, as described here, can occur with each recall visit. The traditional frequency of visits has been every 6 months; however, certain patients (especially those in full orthodontic appliances) can seen more frequently at the clinician’s preference.

At-Home Proximal Fluoride Delivery

For orthodontic patients, as well as those with high caries susceptibility and poor flossing compliance, the above “in-office” protocol can be duplicated at home using a prescription 5000 ppm sodium fluoride gel. Another option is a 0.40% stannous fluoride gel (Enamelon® Preventive Treatment Gel, Premier Dental Products), which has 970 ppm fluoride and excellent fluoride ion uptake (Figure 8).2 Young patients (and their parents) are instructed to first complete the daily brushing and flossing routine, then dip the interdental pick into the gel and insert it into each interproximal space in the same manner as described for in-office delivery (Figure 5 through Figure 7). In addition, the Enamelon can be used as a daily dentifrice.


Because compliance with dental flossing is often less ideal among young patients, interdental picks can assist in removing food debris and bacteria from interproximal sites. In addition, if the picks are coated with preventive fluoride solutions and used frequently, it logically follows that the occurrence of proximal decalcification and caries will decrease. Further research, such as an in vitro study in an artificial caries model using extracted teeth, could confirm that proximal sites are better protected by the fluoride delivery methods and materials suggested here.


Neither author has any financial interest in any product or company mentioned in this article, and there was no remuneration of any kind for the production of this work.

Editor’s note: Look for Part II of this article, “Caries Interception with Silver Diamine Fluoride,” in an upcoming issue of Inside Dentistry.


1. Croll TP, Berg JH. Use of fluoride products for young patients at high risk of dental caries. Compendium Contin Educ Dent. 2014;35(8):602-606.

2. Croll TP, DiMarino JC. A Review of Contemporary Dentifrices. RDH. 2014;34(9):[Suppl].

About the Author

Theodore P. Croll, DDS
Private Practice
Doylestown, Pennsylvania
Affiliate Professor
Department of Pediatric Dentistry, UW School of Dentistry
Seattle, Washington Adjunct Professor
Department of Pediatric Dentistry, UT Health Science Center
San Antonio, Texas

Joel H. Berg, DDS, MS Dean
University of Washington School of Dentistry
Seattle, Washington

© 2021 AEGIS Communications | Privacy Policy