Effect of fluoridated bleaching gels on the remineralization of predemineralized bovine enamel in vitro.
OBJECTIVE
This study evaluated possible differences regarding the remineralization of predemineralized enamel after exposure to fluoridated or non-fluoridated bleaching gels.


METHODS
120 enamel specimens were prepared from sixty bovine incisors; before and after demineralization (37 degrees C; pH 4.95; 10d), one-quarter of each specimen's surface was covered with nail varnish (control sound/demineralized). Subsequently, the specimens were stored for 16h daily in a remineralizing solution (pH 7.0; 14d), while for the remaining time (8h) various bleaching gels were applied: (1) no treatment (control), (2) Opalescence regular (O, Ultradent), (3) Opalescence PF (O-PF), (4) Nite White ACP (NW-ACP, Discus Dental) and (5) Nite White ACPF (NW-ACPF). Following, half of the bleached parts were nail-varnished and stored for another 3-weeks period in a remineralizing solution. Differences in mineral losses (DeltaDeltaZ) and lesion depths (DeltaLD) before and after treatment/remineralization period were evaluated from microradiographs. DeltaDeltaZ(surface) values (mineral loss of the outer 18microm of the lesion) were calculated.


RESULTS
After 2 and 5 weeks DeltaDeltaZ/DeltaLD values of the bleaching groups did not differ significantly from the controls. Treatment with NW-ACPF for 2 weeks resulted in significantly lower DeltaDeltaZ values compared to NW-ACP (p=0.032) and NW-ACPF in higher values than Opalescence regular (p=0.006). Two weeks treatment with O and O-PF resulted in decreased DeltaDeltaZ(surface) values compared to control (p<0.0005), whereas with NW-ACPF no significant differences could be observed (p=0.062). Application of NW-ACP induced significantly increased DeltaDeltaZ(surface) values compared to control (p=0.001).


CONCLUSIONS
No supporting influence of fluoride-containing bleaching gels on remineralization could be observed.
Tschoppe
Peter
P
Department of Operative Dentistry and Periodontology, University School of Dental Medicine, CharitéCentrum 3, Germany. peter.tschoppe@charite.de
Neumann
Konrad
K
Mueller
Jan
J
Kielbassa
Andrej M
AM
D000818:Animals; D002130:Calcium Phosphates / Q000008:administration & dosage / Q000627:therapeutic use; D000077463:Carbamide Peroxide; D002327:Cariostatic Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D002417:Cattle; D003743:Dental Enamel / Q000187:drug effects* / Q000473:pathology; D004338:Drug Combinations; D005459:Fluorides / Q000008:administration & dosage / Q000627:therapeutic use*; D006813:Humidity; D006863:Hydrogen-Ion Concentration; D008422:Materials Testing; D008852:Microradiography; D008903:Minerals / Q000032:analysis; D016877:Oxidants / Q000008:administration & dosage / Q000627:therapeutic use*; D010545:Peroxides / Q000008:administration & dosage / Q000627:therapeutic use; D011897:Random Allocation; D013696:Temperature; D013997:Time Factors; D014073:Tooth Bleaching / Q000379:methods*; D017001:Tooth Demineralization / Q000188:drug therapy* / Q000473:pathology; D014089:Tooth Remineralization; D014508:Urea / Q000008:administration & dosage / Q000031:analogs & derivatives / Q000627:therapeutic use
D002130:Calcium Phosphates; D002327:Cariostatic Agents; D004338:Drug Combinations; D008903:Minerals; D016877:Oxidants; D010545:Peroxides; C519480:amorphous calcium phosphate; D000077463:Carbamide Peroxide; D014508:Urea; D005459:Fluorides