title: Assesment of artificial caries lesions through scanning electron microscopy and cross-sectional microhardness test.
abstract: OBJECTIVE
  To assess through scanning electron microscopy (SEM) and cross-sectional microhardness (CSMH) test whether the methodology exposed in this experiment can be used to produce artificial active white spot lesions (AAWSLs) on smooth unabraded human dental enamel.
  
  
  METHODS
  Ten human permanent molars were used in this experiment. One section of each tooth was double coated with nail varnish except for a limited central area sized 2.5 mm × 1 mm (2.5 mm 2 ). Each specimen was individually exposed to 10.4 ml of a demineralizing solution at pH 5.0, during 42 days (37°C) without agitation. Samples were sectioned in the center of the AAWSL and one half was analyzed in SEM and the other half was subjected to CSMH. Descriptive statistics was performed to determine mean depth of the lesion.
  
  
  RESULTS
  The mean depth of AAWSL was 100 μm (s.d. =12.1) and a white dull rough surface could be detected by the unaided eye. SEM images demonstrated that although some surface areas of the lesion appeared to be relatively intact, erosion was present. A prismatic pattern of dissolution was observed in all samples with an enlargement of the prism sheaths and some samples had also sites of destruction of prism cores.
  
  
  CONCLUSIONS
  This methodology can be used to induce AAWSLs in human dental enamel but surface erosion has to be taken into account when performing CSMH test.
authors: Department of Community and Preventive Dentistry of Rio de Janeiro, Rio de Janeiro, Brazil.
authors: Mirian de Waele Souchois
authors: Mde W
authors: de Marsillac
authors: Ricardo de Sousa
authors: Rde S
authors: Vieira
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry; D000328:Adult; D019412:Anatomy, Cross-Sectional; D003731:Dental Caries / Q000473:pathology*; D003743:Dental Enamel / Q000648:ultrastructure; D003747:Dental Enamel Solubility; D017886:Durapatite / Q000737:chemistry; D005459:Fluorides / Q000737:chemistry; D006244:Hardness; D006801:Humans; D006863:Hydrogen-Ion Concentration; D019344:Lactic Acid / Q000737:chemistry; D008855:Microscopy, Electron, Scanning; D013696:Temperature; D013997:Time Factors; D017001:Tooth Demineralization / Q000473:pathology
chemical_list: D000180:Acrylic Resins; D019344:Lactic Acid; C006903:carbopol 940; D017886:Durapatite; D005459:Fluorides