Dr. Berg - Pediatric Case Study

Use of Phocal Fluoride pHn Disks in Interproximal Lesions in Pediatric Populations –

A Case Study
Joel Berg, Amy Kim, Sung Mo Ku, and Rebecca Slayton
The Center for Pediatric Dentistry at University of Washington


Dental caries is an oral health disease thought to be in decline due to improvements in oral hygiene practices and fluoridation of water.  It may be declining in certain population subsets while others are experiencing increases in caries rates. This case study explored feasibility and ease of use of a new treatment paradigm in caries prevention and possible arrest, Phocal Fluoride Disks, in a pediatric patient.  Feasibility and ease of use was assessed at initial placement of device; and the disks’ caries arrest effects were observed in an interproximal incipient lesion over a period of 4 months.

Key Words: Early caries, Phocal Fluoride, interproximal incipient lesion, caries prevention, fluoride treatment.

Dental caries is a world-wide epidemic that affects approximately 9% of the pediatric population, or 620 million children. (Vos et al, 2012)  It is estimated to be the most common chronic childhood disease, around 5 times more prevalent than asthma according to Healthy People 2010. Once a disease of nearly universal occurrence for nearly all children, tooth decay is now generally distributed in the pediatric population to the point that roughly 80 percent of caries in permanent teeth is concentrated in 25 percent of U. S. children. (Kaste et al, 1988)  The high-risk, high-prevalence, high-severity group, which currently represents nearly 20 million children, is largely comprised of low-income children (nearly all of whom are eligible for Medicaid or SCHIP), with higher levels of caries found in African-American and Hispanic groups at all ages. (Vargas et al, 1998)  The US Department of Health and Human Services also notes that the minority and low-income children disproportionately experience decay in their primary teeth in their “Guide to Children’s Dental Care in Medicaid.”

Dental clinicians have differing philosophies regarding early caries in pediatric populations. Some dentists take a “wait and see” approach and follow white lesions until they become frank cavities. Others take a more aggressive approach and “drill fill and bill” for all questionable lesions. Although both options are viable, once tooth structure is removed there is no way to restore it back to enamel.  The tooth may fare well with a small restoration and the patient may have fine outcomes with no sensitivity or need for future treatment. However, common sequelae from restorative treatment include the need for more invasive restorative treatment; root canal and crown; and/or failure altogether. Clearly it is best when a tooth may remain whole.

Phocal Fluoride disks are a product that may be part of a paradigm shift to focus on prevention and treatment of early caries with medicinal therapeutics rather than restorative interventions. Phocal Fluoride disks are topical delivery vehicles designed to fluoridate interproximal tooth surfaces. This action aids in the prevention of dental caries on intact surfaces, arrests progress on surfaces with incipient carious lesions and enhances remineralization. The disks contain 1.23% fluoride and expand when positioned interproximally into a gel; and release fluoride for approximately 10 minutes before biodegrading.

This case study assessed the capability of the Phocal pHn disks to affect any changes on existing interproximal incipient lesions in a pediatric patient following a period of 4 months.  Feasibility and ease of use in a pediatric patient was also assessed.



A 3 year old male patient of record at the Center for Pediatric Dentistry was diagnosed with early caries in the interproximal area of teeth E and F.  The early caries lesion was characterized as an intact chalky white enamel surface with shadowing that spans the mesial surfaces of E and F.

A non-acidic sodium fluoride pHn disk was placed between teeth E and F following manufacturer’s guidelines below:

Prior to treatment using either of the placement methods below, all debris and calculus should be removed from the selected site(s) and the site(s) should remain dry during placement. Premature wetting softens the disks and can compromise correct interproximal placement.

The clinician noted that the placement of the pHn disk after wedging teeth E and F was quick, easy, and minimally invasive.  The patient was very cooperative and stated there was no discomfort or objectionable tastes or smells. The patient commented he felt “something between my teeth” but did not complain of any pain or discomfort.

The patient completed the recall and prophy visit after placement of the Phocal Fluoride pHn disk without incident.  The patient remained highly cooperative and reported no complaints.

The patient returned for a follow-up visit after 4 months.  The interproximal early caries lesion noted at baseline had not progressed, and looked as though it had remineralized.  When the surface of the lesion was examined with an explorer, it was noted to be quite solid.  The parent stated there were no complaints or adverse events after placement of the Phocal Fl disk at the last visit.



This case study assessed the feasibility, and ease of use of the Phocal Fluoride pHn disks in pediatric populations; and observed any changes on existing interproximal incipient lesions in a pediatric patient following a period of 4 months. 

Based on our clinical and radiographic observations, we concluded that the Phocal Fluoride pHn disk is a viable non-invasive treatment modality possibility for incipient or early caries lesions in pediatric populations due to quick placement times, simple technique, and minimal armamentarium required. 

After following up with the patient after a period of 4 months we found that the early caries lesion in the interproximal areas of E and F had not progressed any further from what was seen clinically prior to treatment.  It is not knowable whether Phocal Fluoride pHn disks affected this lack of disease sequeale; however, it was a positive clinical outcome nonetheless.  One that required no “drilling and filling” for this child at this early stage of development.