911 Enamel remineralization by amelogenin-containing hydrogel with oral simulated biofilm

Friday, March 23, 2012: 2 p.m. - 3:15 p.m.
Presentation Type: Poster Session
Y. FAN, Department of Comprehensive Dentistry and Biomaterials, Louisiana State University, New Orleans, LA, S. LIAO, School of Dentistry, Louisiana State University, New Orleans, LA, Z. WEN, Health Sciences Center, Oral and Craniofacial Biology, Louisiana State University, New Orleans, LA, and X. XU, Comprehensive Dentistry & Biomaterials, Louisiana State University, New Orleans, LA

Enamel remineralization with the assistant of fluoride and recombinant full-length amelogenin has been proven a promising approach via the formation of enamel-like nanocrystals. Objectives: To investigate the effect of amelogenin-containing hydrogels on the enamel hardness at the initial stage of remineralization in the presence oral simulated biofilms. Methods: Amelogenin-containing remineralization hydrogels were prepared and the releasing profile of protein and ions was tested. Artificial caries on tooth slabs were generated by etching in pH=4.5 lactic acid. Thirty tooth slabs were treated for 5 days with three remineralization hydrogels (n=10 each group) in the presence of ten-multispecies oral biofilm in a constant depth film fermentor (CDFF) (pH=7.2 continuous flow 0.5ml/min, at 5%CO2 and 95%N2, 37oC): Gel-1: hydrogel containing amelogenin (100ug/mL) and [Ca]=2.5mM, [PO4]=1.5mM and [F]=10mg/L. Gel-2 contained no amelogenin; other compositions were the same as Gel-1. Gel-3 contained no amelogenin and fluoride; other compositions were the same as Gel-1. Knoop's hardness numbers (KHN) were tested by a microhardness tester (Buehler) with 25g force. ANOVA with Tukey's post-hoc test was used to compare the five materials' increase in hardness.

Results: Table 1. Knoop hardness before and after remineralization (Mean±SD)



Gel -2

Gel -3





Artificial Caries(AC)




Remineralization Treatment(RT)




Increase (RT-AC)




Lower-case superscripts indicate grouping in each column. Upper-case superscripts indicate grouping in last row. Different letters indicate significant difference (p<0.05).

Treatment with all three remineralization hydrogels increased the surface hardness significantly (p<0.05).  Gel-1 group had significantly greater hardness increase than Gel-2 and Gel 3 (p<0.001). Densely-packed enamel-like nanorods were observed on the tooth in Gel-1. Conclusions: Remineralization hydrogel containing amelogenin and fluoride leads to a significant recovery of the hardness of eroded enamel in CDFF multispecies oral biofilm models. Supported by NIH/NCRR-COBRE grant 5P20RR020160-05.


This abstract is based on research that was funded entirely or partially by an outside source: NIH/NCRR COBRE grant (5P20RR020160-05)

Keywords: Cariology, Enamel and Mineralization