title: In vitro re-hardening of artificial enamel caries lesions using enamel matrix proteins or self-assembling peptides.
abstract: OBJECTIVE
  To assess the re-hardening potential of enamel matrix derivatives (EMD) and self-assembling peptides in vitro, hypothesizing that these materials may increase the mineralization of artificial carious lesions and improve hardness profiles.
  
  
  METHODS
  Forty-eight enamel samples were prepared from extracted bovine lower central incisors. After embedding and polishing, nail varnish was applied, leaving a defined test area. One third of this area was covered with a flowable composite (non-demineralized control). The remaining area was demineralized in an acidic buffer solution for 18 d to simulate a carious lesion. Half the demineralized area was then covered with composite (demineralized control), while the last third was left open for three test and one control treatments: (A) Application of enamel-matrix proteins (EMD - lyophilized protein fractions dissolved in acetic acid, Straumann), (B) self-assembling peptides (SAP, Curodont), or (C) amine fluoride solution (Am-F, GABA) for 5 min each. Untreated samples (D) served as control. After treatment, samples were immersed in artificial saliva for four weeks (remineralization phase) and microhardness (Knoop) depth profiles (25-300 µm) were obtained at sections. Two-way ANOVA was calculated to determine differences between the areas (re-hardening or softening).
  
  
  RESULTS
  Decalcification resulted in significant softening of the subsurface enamel in all groups (A-D). A significant re-hardening up to 125 µm was observed in the EMD and SAP groups.
  
  
  CONCLUSIONS
  This study showed that EMD and SAP were able to improve the hardness profiles when applied to deep demineralized artificial lesions. However, further research is needed to verify and improve this observed effect.
authors.affiliation: Clinic of Preventive Dentistry, Periodontology and Cariology, Center of Dental Medicine, University of Zurich, Zurich, Switzerland.
authors.forename: Patrick
authors.initials: P
authors.lastname: Schmidlin
authors.affiliation: Clinic of Preventive Dentistry, Periodontology and Cariology, Center of Dental Medicine, University of Zurich, Zurich, Switzerland.
authors.forename: Katja
authors.initials: K
authors.lastname: Zobrist
authors.affiliation: Clinic of Preventive Dentistry, Periodontology and Cariology, Center of Dental Medicine, University of Zurich, Zurich, Switzerland.
authors.forename: Thomas
authors.initials: T
authors.lastname: Attin
authors.affiliation: Clinic of Preventive Dentistry, Periodontology and Cariology, Center of Dental Medicine, University of Zurich, Zurich, Switzerland.
authors.forename: Florian
authors.initials: F
authors.lastname: Wegehaupt
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D002417:Cattle; D003731:Dental Caries; D003743:Dental Enamel / Q000737:chemistry*; D003746:Dental Enamel Proteins / Q000737:chemistry*; D006244:Hardness; D008422:Materials Testing; D012016:Reference Values; D015203:Reproducibility of Results; D012464:Saliva, Artificial / Q000737:chemistry; D018709:Statistics, Nonparametric; D013499:Surface Properties; D013997:Time Factors; D017001:Tooth Demineralization; D014089:Tooth Remineralization / Q000379:methods
chemical_list: D003746:Dental Enamel Proteins; D012464:Saliva, Artificial; C109069:enamel matrix proteins