In vitro re-hardening of artificial enamel caries lesions using enamel matrix proteins or self-assembling peptides

Abstract

Objectives 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.Material and 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.

Effect of self-assembling peptide P11-4 on orthodontic treatment-induced carious lesions

“…The greater difference between test and control lesions, however, occurred in the impedance values compared with that in the morphometric measurements, thereby confirming that SAP P 11 -4 acts predominantly by regenerating the mineral structure of the enamel of the lesion body and not just the surface 23,24 . Moreover, at the last study visit at day 180, the impedance values for test lesions indicated regression of caries into very outer enamel, whereas the impedance values for the control lesions indicated still caries throughout the whole enamel layer 31,33 , which agrees with previous data that fluoride (in the present study as fluoride-based professional prophylaxis paste and home care toothpaste) only acts in the top 30-50 µm of the enamel surface 13,14,34 .…”

Effects of Self-Assembling Peptide P11-4, Fluorides, and Caries Infiltration on Artificial Enamel Caries Lesions in vitro

“…At pH >7.2, P11-4 is obtained as an isotropic fluid which is supposed to transform into a viscous birefringent nematic state in the pH range 5.0-7.0 [Aggeli et al, 2003]. In the nematic state P11-4 seems to promote remineralization in vitro [Kirkham et al, 2007;Jablonski-Momeni and HeinzelGutenbrunner, 2014;Schmidlin et al, 2016] by presumably diffusing into the lesions and producing 3-dimensional gels comprising β-sheet aggregates [Aggeli et al, 2003]. Therefore, it might be speculated that an effect of the enhanced incorporation of Ca 2+ and PO 4 3-from saliva (and thus pronounced remineralization) after the application of the self-assembling peptide might be observed in the same setting but under net-remineralizing conditions.…”

“…Although these results were stable for 6 months, only 11 lesions were included and the study design included neither a positive (e.g., fluoridation) nor a negative control (placebo/no treatment). In vitro, a significant increase in the subsurface microhardness could be observed after the application of Curodont TM Repair [Schmidlin et al, 2016]. Furthermore, after the application of Curodont TM Repair significantly improved quantitative light-induced fluorescence values could be observed in another in vitro study, but only when 2 control groups were merged in the analysis [Jablonski-Momeni and Heinzel-Gutenbrunner, 2014].…”

State of the Art Enamel Remineralization Systems: The Next Frontier in Caries Management

“…Moreover, net salivary remineralization is a slow process [Dowd, 1999], with a tendency for mineral gain only on the surface of the WSL due to the low ion concentration gradient from saliva into the lesion [Silverstone, 1972]. Fluoride-mediated salivary remineralization is also seen to be restricted to the outer 30 μm of the tooth [Schmidlin et al, 2016]. This surface-only remineralization improves neither the aesthetics nor the structural properties of the subsurface lesion [Cochrane et al, 2010].…”

“…The P11-4 fibrillar matrix has a high affinity for Ca 2+ ions and acts as a nucleator for de novo HA formation resulting in remineralization of the lesion body [Kind et al, 2017;Kirkham et al, 2007]. Analysis of in vitro data showed that the presence of P11-4 fibres in the lesion body resulted in faster HA formation, yielding tangentially arranged needle-shaped crystals, with increased microhardness of the remineralized subsurface lesion [Schmidlin et al, 2016;Sousa et al, 2017;Takahashi et al, 2016].…”