Daily exposure to fluoride mouthrinse produces sustained fluoride release from orthodontic adhesives in vitro.
OBJECTIVE
To determine firstly, if sustained fluoride release can be achieved from five orthodontic adhesives: Ketac-Cem, Fuji ORTHO LC, Sequence, Transbond and Right-On, with daily exposure to fluoride mouthrinse in vitro, and secondly, if sustained fluoride release can be re-established from the same specimens, after an interruption in mouthrinse exposure.


METHODS
Ten brackets were bonded to bovine incisors using each adhesive. Each adhesive group was divided equally into a test and a control sub-group. In phase 1 (42 days), the test sub-groups were exposed for 1min daily to fluoride mouthrinse (225 ppm), followed by immersion in de-ionised water for 42 days to deplete their fluoride reserves. Mouthrinse exposure was then resumed in phase 2 (28 days). Mean cumulative fluoride release (MCFR) was calculated for days 0-21 of phase 1 and for the plateau portion of the fluoride release curves in phase 1 (days 21-42) and phase 2 (days 7-28).


RESULTS
During phase 1, the MCFR for each test sub-group was significantly greater than its control (p<0.05). There was no significant difference in MCFR between the curve plateau portion of phases 1 and 2 for all adhesives except Transbond, for which MCFR was less in phase 2 (p<0. 05).


CONCLUSIONS
Sustained fluoride release occurred for each adhesive exposed daily to fluoride mouthrinse, at a level significantly greater than its control. After fluoride exhaustion, re-exposure to daily fluoride mouthrinse produced sustained fluoride release levels comparable to those prior to exhaustion, for all adhesives except Transbond.
Benington
P C
PC
Unit of Orthodontics, Glasgow Dental Hospital and School, 378 Sauchiehall Street, G2 3JZ, Glasgow, UK.
Gillgrass
T J
TJ
Foye
R H
RH
Millett
D T
DT
Gilmour
W H
WH
D000180:Acrylic Resins; D000538:Aluminum Silicates; D000704:Analysis of Variance; D000818:Animals; D019540:Area Under Curve; D017438:Bisphenol A-Glycidyl Methacrylate; D002417:Cattle; D001840:Dental Bonding; D017220:Dentin-Bonding Agents / Q000737:chemistry*; D005459:Fluorides / Q000008:administration & dosage*; D005899:Glass Ionomer Cements / Q000737:chemistry*; D017736:Ion-Selective Electrodes; D008277:Magnesium Oxide; D008689:Methacrylates; D009067:Mouthwashes / Q000737:chemistry*; D016910:Orthodontic Brackets; D011076:Polycarboxylate Cement; D011140:Polyurethanes; D019279:Resin Cements / Q000737:chemistry*; D015034:Zinc Oxide
D000180:Acrylic Resins; D000538:Aluminum Silicates; D017220:Dentin-Bonding Agents; C095451:Fuji Ortho LC; D005899:Glass Ionomer Cements; D008689:Methacrylates; D009067:Mouthwashes; D011076:Polycarboxylate Cement; D011140:Polyurethanes; D019279:Resin Cements; C091935:Sequence (bonding agent); C071164:Right-On cement; C065742:Transbond; D008277:Magnesium Oxide; D017438:Bisphenol A-Glycidyl Methacrylate; C040235:Ketac-cem; D005459:Fluorides; D015034:Zinc Oxide