Stability of two resin combinations used as sealants against toothbrush abrasion and acid challenge in vitro.
OBJECTIVE
To test the stability of two conventional adhesives when combined with a low-viscosity caries infiltrant used for sealing sound enamel against toothbrush abrasion and acid challenge in vitro.


METHODS
Bovine enamel discs (Ø = 3 mm) randomly assigned to three groups (n = 10/group) were etched with 37% phosphoric acid for 30 s and treated with resins of different monomer contents forming three test groups: (1) Untreated specimens (Control); (2) Infiltrant (Icon, DMG) + conventional enamel bonding adhesive (Heliobond, Ivoclar Vivadent); and (3) Infiltrant + conventional orthodontic adhesive (Transbond XT Primer, 3M Unitek). All specimens were immersed in hydrochloric acid (pH 2.6) for up to 9 days, during which they were exposed to 1825 toothbrush-strokes per day. Calcium dissolution was assessed using Arsenazo III method at 24-h intervals. Data were analyzed by Kruskal-Wallis and Wilcoxon signed ranks tests.


RESULTS
Cumulative calcium dissolution for the untreated specimens (39.75 ± 7.32 μmol/ml) exceeded the sealed groups (Icon + Heliobond: 23.44 ± 7.03 μmol/ml; Icon + Transbond XT Primer: 22.17 ± 5.34 μmol/ml). Untreated specimens presented a relatively constant calcium dissolution rate throughout the experimental period, whereas the sealed groups presented a gradual increase indicating weakening of the seal by toothbrush abrasion. Both sealed groups presented significantly lower daily calcium dissolution at all time points compared to the control, except for Group 2 on the last measurement day.


CONCLUSIONS
Low-viscosity caries infiltrant application on sound enamel prior to conventional resin application provided a protective effect against enamel demineralization, but this effect was not stable when challenged mechanically by toothbrush abrasion.
Department of Orthodontics, University of Ege , Izmir , Turkey.
Enver
E
Yetkiner
Florian Just
FJ
Wegehaupt
Rengin
R
Attin
Annette
A
Wiegand
Thomas
T
Attin
D000134:Acid Etching, Dental / Q000379:methods; D000179:Acrylates / Q000627:therapeutic use; D000818:Animals; D001150:Arsenazo III; D002118:Calcium / Q000032:analysis; D002417:Cattle; D004396:Coloring Agents; D003743:Dental Enamel / Q000737:chemistry / Q000473:pathology*; D003764:Dental Materials / Q000737:chemistry; D006851:Hydrochloric Acid / Q000737:chemistry; D010756:Phosphoric Acids / Q000737:chemistry; D010895:Pit and Fissure Sealants / Q000627:therapeutic use*; D011897:Random Allocation; D019279:Resin Cements / Q000627:therapeutic use; D012117:Resins, Synthetic / Q000627:therapeutic use*; D012995:Solubility; D013997:Time Factors; D014072:Tooth Abrasion / Q000517:prevention & control*; D014077:Tooth Erosion / Q000517:prevention & control*; D014099:Toothbrushing / Q000295:instrumentation
D000179:Acrylates; D004396:Coloring Agents; D003764:Dental Materials; D010756:Phosphoric Acids; D010895:Pit and Fissure Sealants; D019279:Resin Cements; D012117:Resins, Synthetic; C477790:Transbond XT; C578177:icon infiltrant; D001150:Arsenazo III; C040415:heliobond; C030242:phosphoric acid; D006851:Hydrochloric Acid; D002118:Calcium
caries infiltrant; sealant; white spot lesion