As a dental professional, how often can I expect to utilize Phocal disks in my everyday practice?
Studies show that on average, 250 surfaces between teeth (five adult patients) are examined by a dentist during a working day. (Jackson and Lazar JADA 1999). Approximately 40 of these surfaces could show subtle initial decay (Winn et al 1996 NHANES III). Although potentially reversible, many will develop a carious lesion within five years (Majare et al Caries Res 1999). Thus, 40 Phocal disks could be used per working day based on radiographic diagnosis alone. Therefore, 8,000 Phocal disks could be used by a dentist during a 200-day working year.
Is there a significant difference in performance between the Apf and pHn versions of Phocal disks?
Since they are less acidic, the Phocal pHn disks will not etch ceramic crowns or tooth-colored restorations while fluoridating and/or remineralizing tooth surfaces. Phocal Apf disks induce an optimized low pH environment that cleans carious debris from lesions and etches tooth surfaces, as well as causing more penetrating remineralization and fluoridation.
For maximum effectiveness in treating incipient interproximal caries, the Phocal Apf disk should be used first for deep fluoridation and remineralization and nanoscopic pH sensitive fluoride deposition over 2-3 months. Then the Phocal pHn disk should be applied 2-6 months later to further fluoridate and remineralize the healing lesion.
Does the site need to be kept dry during disk application, and if so, does a rubber dam need to be used?
The treatment site and the Phocal disk should remain dry during placement. After placement, the disk absorbs saliva to promote disk biodegration, thus a rubber dam should not be used.
What are isocaps and negative pressure that result at interproximal sites, and how do Phocal disks overcome these problems?
Interproximal sites that are not submerged in saliva form capillaries called isocaps, which are similar to water between two glass slides. These isocaps induce a negative pressurized micro environment (which can even bend glass slides) (O’Brien 1978). This restricts the flow of therapeutic and preventive agents such as fluoride into interproximal sites.
Because Phocal disks are inserted directly into the interproximal site, they effectively break the isocap and directly deposit fluoride to prevent and remineralize interproximal caries.
Can Phocal disks be directly inserted between all teeth?
Yes. Phocal disks can be placed effectively between any teeth. In some cases, the teeth may require separation prior to insertion.
How long does Phocal’s fluoride reservoir last after treatment?
Phocal disks deposit nanoscopic calcium fluoride-like particles that serve as long-term (2-3 months) pH-sensitive, fluoride reservoirs. The initial fluoridation and the pH sensitive fluoride release cause the fluoride to be incorporated in the apatite tooth crystals making them more resistant to caries and enhancing remineralization (Chow and Vogel Operative Dent 2001).
Will using a protective varnish in concert with a Phocal disk increase the effectiveness of the treatment?
Yes. After placement of a Phocal Apf or Phocal pHn disk, the buccal or lingual portion can be coated with a protective varnish. When using the folding technique, after placement, the buccal and occlusal portions can be coated with a protective varnish. Nevertheless, it is important to not cover the entire disk with varnish.
Is it necessary to treat a problematic interproximal area more than once?
For maximum benefit and effectiveness, patients may be recalled at intervals of 2-12 months for repeated treatments. This depends on the lesion size, the patient’s caries risk patterns and their interproximal oral hygiene.
What instruments and materials will I need for the placement of Phocal disks?
No unusual equipment is required. To obtain a dry site for placement, the use of cotton rolls and/or gauze is recommended (a rubber dam should not be used). For placement, a pair of good thin forceps is suggested. In some cases, you may choose to use a separator and/or wedge to assist with disk placement. A fluoride varnish and applicator will be required when adding varnish to the inserted Phocal disk.
What instructions should I give my patients after disk placement?
Advise the patient:
- They may experience slight discomfort immediately after placement but this will ease as the disks biodegrade.
- The patient should not eat, drink or rinse for at lest 30 minutes after treatment and obviously the patient should not floss or brush the site for the 30 minutes after treatment. If a varnish is used, flossing and brushing of the site should be avoided for about 8 hours.
- Routine systemic and topical administrations of fluoride should be suspended during the day of application.
