829 Two-way Permeability of Ion Permeable Mirocapsules for Remineralization

Friday, March 23, 2012: 2 p.m. - 3:15 p.m.
Presentation Type: Poster Session
T. GREVING1, M.Q. SCHMIDT2, W. MCHALE3, M.A. LATTA4, and S. GROSS1, 1Creighton University, Omaha, NE, 2Chemistry, Creighton University, Omaha, NE, 3Product Development, Premier Dental Products Company, Plymouth Meeting, PA, 4School of Dentistry, Creighton University, Omaha, NE

Objectives: The objective of this study was to measure the release of calcium, phosphate and fluoride ions from microcapsules with ion permeable membranes that have been charged or recharged with aqueous salt solutions.  Methods: A heterogeneous polymerization technique was utilized to prepare a series of microcapsules with an ethylene glycol based polyurethane shell containing nanopure water or different aqueous solutions of potassium phosphate dibasic or potassium phosphate dibasic of different concentrations.  Ion release profiles of charged and recharged microcapsules were studied as a function of initial ion concentration within the microcapsule, ion concentration of the charging solution, time of exposure to the charging solution, ion identity (fluoride, phosphate, calcium) and temperature. Phosphate ion detection was performed by the molybdenum blue method.  Calcium and fluoride ion release measurements were performed using ion specific electrodes.  Results:   Ion release profiles of ions released from charged and recharged microcapsules were studied under various conditions.  A table highlighting some of the results is shown below.

Salt in the recharging solution

Concentration of charging solution

1 hour (ppm)

4 hours

(ppm)

12 hours

(ppm)

24 hours

(ppm)

Potassium phosphate dibasic

0.4

3

10

17

22

Potassium phosphate dibasic

0.8

15

31

86

125

Potassium Phosphate Dibasic

1.6

7

14

35

59

Potassium Phosphate Dibasic

2.4

2

3

4

4

Calcium Nitrate

0.8

24

59

145

167

Conclusions: Ion release profiles were generated for charged and recharged microencapsulated aqueous solutions that contained biologically available ions useful in remineralization.  The potential for recharging the microcapsules compounded in a variety of dental formulations was demonstrated.  This work is funded in part by Premier Dental Products Incorporated, GL Materials Research LLC and an NSF University-Industry Partnership grant.

This abstract is based on research that was funded entirely or partially by an outside source: NSF/EPSCoR University-Industry Partnership Grant

Keywords: Dental materials, Mineralization, Remineralization and varnish