Prevention of Enamel Demineralization by Use of K18-smooth Surface Sealant

Esthetics is a motivating factor to seek orthodontic treatment. However, if oral hygiene is
inadequate during fixed appliance wear, unsightly white spot lesions (WSL) may develop. WSLs
are areas of enamel demineralization that develop due to microbial assault that manifest as
white, chalky opacity on the enamel. Urethane dimethacrylate (UDMA) can be modified to
produce an antimicrobial compound, UDMA-K18, that has been proven to decrease microbial
attachment in-vitro. (Sticker 2016) The use of a UDMA-K18 containing sealant may help to
eliminate the development of WSLs around orthodontic brackets.

This study will place experimental or control smooth surface resins on teeth that are
scheduled to be extracted for orthodontic reasons. These teeth are typically bicuspids that
are to be extracted to create room for the orthodontic movement of teeth. These teeth are
usually not extracted at the advent of first orthodontic bracket bonding but are extracted
about 30 days later. The design of this study is to place sealants on those teeth (or as
control, no sealant) and evaluate the teeth after they have been extracted.

Design: The study is a prospective, paired randomized control trial for which treatment (no
sealant, UDMA-control, or UDMA-K18 sealant) will be applied clinically and evaluated on
extracted teeth in laboratory conditions.

Procedures: Before bonding, one premolar per patient will be assigned to a group. The group
each premolar is assigned to will be determined by a randomized, computer generated program.
The allocation will be concealed in an opaque envelope that will be opened at the time of
initial bonding. If a fourth premolar is planned for extraction, a random selection of the
treatments will be selected in a 1:1:1 ratio and this treatment will be applied to the fourth
premolar.

At the time of initial bonding, the UDMA and UDMA-K18 sealant will be applied to the selected
premolar following manufacturer instructions. Briefly, the clinician will isolate the teeth
using the NOLA Dry Field System and excess saliva will be removed by drying the teeth with an
air-water syringe. In the treatment group, 37 % Phosphoric Acid will be applied to the entire
buccal surface for 30 seconds, rinsed, and dried. Next, the assigned sealant will be evenly
applied to the entire buccal surface of the premolar and light cured. The sealant which is
adhesive will be applied to the bracket pad and the bracket pad will be pushed to place,
excess cement will be removed and light cured.

In the control group, 37 % Phosphoric Acid will be applied for 30 seconds strictly to the
area where the bracket will be bonded on the buccal surface, rinsed, and dried. No sealant
will be applied. The adhesive sealant will be applied to the bracket pad and the bracket pad
will be pushed to place, excess cement will be removed and light cured. After 3-6 weeks, the
patient will have their premolars extracted. After extraction they will be placed in a Tooth
Storage Solution (25 % ethanol, 75 % water with the addition of saturated hydroxyapatite, 20
mg of NaN3, and 40 mg Thymol) that is antimicrobial and does not alter the tooth surface.
These teeth will be collected by the investigators for histologic study.

The collected, extracted teeth will be sectioned using a water-cooled, Buhler slow speed
diamond saw in three 2mm sections through the bracket base. A polarized light microscopy
(PLM) digitized photograph of the cross-sectional sample will be analyzed to determine the
depth of lesions, if present. The mineral density profile will be analyzed using contact
micro radiography (TMR).

Inclusion Criteria:

- Orthodontic patients at the Department of Orthodontics Clinic, School of Dental
Medicine, University of Colorado who agree to consent to this study.

- Orthodontic treatment plans that include fixed appliances from the second premolar to
second premolar in both arches.

- Orthodontic treatment plans that include extractions of at least 3 bicuspids at about
1 month after bracket placement.

- The patient has adequate oral hygiene

Exclusion Criteria:

- Evidence of decalcification or restorations on any of the premolars planned for
extraction prior to orthodontic treatment,

- Pregnant women (self reported)

- Any condition that contraindicates orthodontic treatment,

- Not willing to consent to the study.