Amorphous calcium phosphate-containing orthodontic composites. Do they prevent demineralisation around orthodontic brackets?
BACKGROUND
A preliminary study using laser fluorescence suggested that amorphous phosphate-containing orthodontic composites may prevent demineralisation around bonded orthodontic brackets.


OBJECTIVE
To compare the microhardness of the enamel around brackets bonded with an amorphous calcium phosphate-containing orthodontic composite (ACP-containing) with the microhardness of the enamel around brackets bonded with a conventional composite resin.


METHODS
Forty extracted upper premolars were used. Orthodontic brackets were bonded to the teeth with either an ACP-containing composite resin (N = 20) or a conventional composite resin (N = 20). The latter were used as the control. The crowns of all teeth were painted with an acid resistant varnish, leaving a 2 mm ring of exposed enamel around the brackets. The teeth were then subjected to a daily cycle of demineralisation for 6 hours and remineralisation for 18 hours for 21 days. Each tooth was sectioned and the microhardness of the enamel determined 25, 50, 75, 100 and 150 microm from the surface.


RESULTS
The enamel was significantly harder 25 microm (p = 0.000) and 50 microm (p = 0.001) from the enamel surface in the teeth with brackets bonded with the ACP-containing composite resin as compared with the control teeth.


CONCLUSIONS
ACP-containing orthodontic composite resins may reduce the enamel decalcification found in patients with poor oral hygiene.
Uysal
Tancan
T
Department of Orthodontics, Erciyes University, Kayseri, Turkey. tancanuysal@yahoo.com
Amasyali
Mihri
M
Koyuturk
Alp Erdin
AE
Ozcan
Suat
S
Sagdic
Deniz
D
D000134:Acid Etching, Dental; D002130:Calcium Phosphates / Q000737:chemistry*; D002327:Cariostatic Agents / Q000737:chemistry*; D003188:Composite Resins / Q000737:chemistry*; D055117:Curing Lights, Dental; D001840:Dental Bonding; D003738:Dental Cements / Q000737:chemistry; D003743:Dental Enamel / Q000648:ultrastructure; D006244:Hardness; D006801:Humans; D008422:Materials Testing; D016910:Orthodontic Brackets; D019279:Resin Cements / Q000737:chemistry*; D013997:Time Factors; D017001:Tooth Demineralization / Q000517:prevention & control*; D014089:Tooth Remineralization
C528777:Aegis Ortho adhesive; D002130:Calcium Phosphates; D002327:Cariostatic Agents; D003188:Composite Resins; D003738:Dental Cements; D019279:Resin Cements; C516047:Transbond XT Light Cure Adhesive Primer; C519480:amorphous calcium phosphate