title: [Comparative study on the penetration abilities of resin infiltration into proximal initial caries lesions in primary molars and permanent posterior teeth].
abstract: OBJECTIVE
  To compare the penetration abilities of resin infiltration into proximal lesions in primary molars and permanent posterior teeth in vitro.
  
  
  METHODS
  Extracted or exfoliated primary molars (n = 32) and permanent posterior teeth (n = 36) with proximal white spot lesions were selected. Roots of the teeth were removed, and the crowns were cut across the caries lesions perpendicular to the surface. Cut surfaces were examined with stereo microscopy and classified with respect to histological lesion extension (C1-C4): Lesions confined to the outer half on enamel (C1), lesions confined to the inner half on enamel(C2), lesions confined to the outer half on dentin(C3), lesions extending into the inner half of dentin (C4). C4 were excluded. Caries lesions were etched for 2 min with 15% hydrochloric acid gel and were subsequently treated for 5 min with resin infiltration. Thin sections from each lesion were prepared and specimens were observed with confocal laser scanning microscopy (CLSM) through a dual-fluorescence staining technique. Lesion depth (LD) and penetration depth (PD) of resin infiltration were measured in primary molars and permanent posterior teeth in confocal microscopic images, and percentage penetration (PP) were calculated respectively. The date were collected and analyzed.
  
  
  RESULTS
  There were no significant differences for overall PP in primary molars and permanent posterior teeth groups (P > 0.05). However, the penetration abilities in primary molars were slight higher than those in permanent posterior teeth in C1 group (P < 0.05). The penetration abilities had no significant difference in primary molars and permanent posterior teeth in both C2 and C3 groups (P > 0.05).
  
  
  CONCLUSIONS
  Resin infiltration have satisfied penetration abilities in primary molars and permanent posterior teeth with proximal initial lesions. The better penetration abilities of resin infiltration in primary molars are shown in Cl lesions than those in permanent posterior teeth.
authors.affiliation: Dept. of Oral Medicine, The Second Hospital of Hebei Medical University, Shijiazhuang 050000, China.
authors.forename: Yonghong
authors.initials: Y
authors.lastname: Liu
authors.forename: Lihong
authors.initials: L
authors.lastname: Ge
authors.forename: Huizhen
authors.initials: H
authors.lastname: Chen
mesh_terms: D003731:Dental Caries; D003743:Dental Enamel; D003804:Dentin; D006801:Humans; D006851:Hydrochloric Acid; D018613:Microscopy, Confocal; D008963:Molar; D014094:Tooth, Deciduous
chemical_list: D006851:Hydrochloric Acid