title: Micro-hardness and mineral loss of enamel lesions after infiltration with various resins: influence of infiltrant composition and application frequency in vitro.
abstract: OBJECTIVE
  The aim of this in vitro study was to evaluate the influence of infiltrant composition and application frequency on micro-hardness and lesion progression after resin infiltration of artificial enamel lesions.
  
  
  METHODS
  In each of 100 bovine enamel samples, three artificial caries lesions were created (pH=4.95, 50 days). After etching two of the lesions (37% phosphoric acid) specimens were randomly allocated to five infiltrants (four experimental infiltrants with different monomer and solvent compositions and penetration coefficients, and one commercial infiltrant [Icon, DMG]). Lesions were then infiltrated and light-cured, and infiltration repeated afterwards for one of the lesions. Infiltrated samples were cut into halves, with one half being demineralised for further 50 days. Micro-hardness (VHN) and integrated mineral loss (ΔZ) were evaluated at baseline and after second demineralisation. Repeated measures ANOVA and paired t-tests were used to analyse influence of material composition and application frequency on micro-hardness and lesion progression (integrated mineral loss difference ΔΔZ).
  
  
  RESULTS
  Resin infiltration significantly increased micro-hardness and reduced lesion progression compared to untreated artificial lesions (p<0.05, t-test). Neither micro-hardness nor lesion progression were significantly influenced by material composition (p>0.05, ANOVA). In contrast, twice application resulted in significantly increased micro-hardness and demineralisation resistance of infiltrated lesions (p<0.05, ANOVA).
  
  
  CONCLUSIONS
  Resin infiltration significantly improves micro-hardness and demineralisation resistance of enamel lesions; these effects are significantly enhanced if resins are applied twice. Experimental resins did not outperform the commercial infiltrant.
  
  
  CONCLUSIONS
  This in vitro study demonstrated that resin infiltration significantly increases both micro-hardness and demineralisation resistance of enamel caries lesions. Twice application of the infiltrant seems to increase these effects. In contrast, the composition of the infiltrant had no significant influence on investigated parameters.
authors.affiliation: Department for Conservative Dentistry and Periodontology, Christian-Albrechts-Universität, Kiel, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Paris
authors.forename: F
authors.initials: F
authors.lastname: Schwendicke
authors.forename: S
authors.initials: S
authors.lastname: Seddig
authors.forename: W-D
authors.initials: WD
authors.lastname: Müller
authors.forename: C
authors.initials: C
authors.lastname: Dörfer
authors.forename: H
authors.initials: H
authors.lastname: Meyer-Lueckel
mesh_terms: D000818:Animals; D017438:Bisphenol A-Glycidyl Methacrylate / Q000737:chemistry; D002417:Cattle; D003188:Composite Resins / Q000008:administration & dosage / Q000737:chemistry*; D003743:Dental Enamel / Q000737:chemistry / Q000648:ultrastructure*; D003764:Dental Materials / Q000737:chemistry*; D018450:Disease Progression; D000431:Ethanol / Q000737:chemistry; D006244:Hardness; D055115:Light-Curing of Dental Adhesives / Q000379:methods; D008852:Microradiography; D008903:Minerals / Q000032:analysis; D010756:Phosphoric Acids / Q000737:chemistry; D011092:Polyethylene Glycols / Q000737:chemistry; D011109:Polymethacrylic Acids / Q000737:chemistry; D011897:Random Allocation; D012117:Resins, Synthetic / Q000737:chemistry; D012997:Solvents / Q000737:chemistry; D013499:Surface Properties; D013997:Time Factors; D017001:Tooth Demineralization / Q000473:pathology*; D062366:para-Aminobenzoates / Q000737:chemistry
chemical_list: D003188:Composite Resins; D003764:Dental Materials; D008903:Minerals; D010756:Phosphoric Acids; D011109:Polymethacrylic Acids; D012117:Resins, Synthetic; D012997:Solvents; C578177:icon infiltrant; D062366:para-Aminobenzoates; C020946:triethylene glycol dimethacrylate; D000431:Ethanol; D011092:Polyethylene Glycols; D017438:Bisphenol A-Glycidyl Methacrylate; C030747:ethyl 4-dimethylaminobenzoate; C030242:phosphoric acid