In vitro microleakage of adhesive-sealed dentin with lactic acid and saliva exposure: a radio-isotope analysis.
OBJECTIVE
The aim of this study was to evaluate the dentin-protective potential of two dentin-bonding systems (Syntac and Clearfil SE Bond) on artificial saliva and lactic acid exposure.


METHODS
Radiochemical analysis in combination with polarization-microscopy was used in the current study. Different applications in MOD preparations in irradiated human molars were compared. Untreated cavities and cavities covered with flowable resin served as controls. Forty-eight specimens were immersed in artificial saliva (pH 7.5), 48 in lactic acid (pH 4). Activity of (32)P was measured between days 1 and 21 and loss of mineralized tissue was estimated.


RESULTS
In lactic acid, cavities sealed with single bond, double bond or bond plus cavity sealer application resulted in significantly lower mineralized tissue loss compared to negative controls (p < 0.05). Upon both saliva and lactic acid exposure, bonding plus sealer application proved to be the most protective treatment (p < 0.05).


CONCLUSIONS
Based on these in vitro findings it may be advisable to use a filled cavity sealer or a flowable resin to protect dentin from demineralization. The radiochemical analysis appeared to be valuable in evaluating the protective potential of bonding agents against dentin demineralization.
Department of Preventive Dentistry, Periodontology and Cariology, Center for Dental and Oral Medicine, University of Zurich, Plattenstrasse 11, P.O. Box 163 Zurich, Switzerland. till.goehring@zzmk.unizh.ch
T N
TN
Göhring
M
M
Zehnder
B
B
Sener
P R
PR
Schmidlin
D000134:Acid Etching, Dental; D000179:Acrylates / Q000627:therapeutic use; D000704:Analysis of Variance; D003188:Composite Resins / Q000627:therapeutic use; D003736:Dental Cavity Lining / Q000379:methods*; D003763:Dental Leakage / Q000517:prevention & control*; D003804:Dentin / Q000187:drug effects*; D017220:Dentin-Bonding Agents / Q000627:therapeutic use*; D006801:Humans; D019344:Lactic Acid / Q000494:pharmacology; D008689:Methacrylates / Q000627:therapeutic use; D008859:Microscopy, Polarization; D008963:Molar; D019279:Resin Cements / Q000627:therapeutic use; D012464:Saliva, Artificial / Q000009:adverse effects; D012588:Scintillation Counting; D018709:Statistics, Nonparametric; D017001:Tooth Demineralization / Q000517:prevention & control*
D000179:Acrylates; C084544:Clearfil Linerbond System; C438313:Clearfil SE Bond; D003188:Composite Resins; D017220:Dentin-Bonding Agents; D008689:Methacrylates; D019279:Resin Cements; D012464:Saliva, Artificial; C078484:Syntac dentine adhesive; C452226:tetric flow composite resin; D019344:Lactic Acid; C040415:heliobond