title: [Micro-CT observations of the adaptation at gingival wall in Class II restorations with different dental restorative materials].
abstract: OBJECTIVE
  To evaluate the adaptation of different materials for gingival layer in Class II restorations using Micro-CT.
  
  
  METHODS
  Eighteen extracted human premolars were selected, and Class II cavities were prepared. The teeth were randomly divided into six groups and restored using layering technique. Six materials were used for gingival layer, including four injectable materials: Beautifil Flow Plus F00 (F00), Beautifil Flow F10 (F10), Filtek Z350 Flowable (Z350F), FujiII LC CAPSULE (Fuji), and two packable materials: BeautifilII (BF), Filtek Z350 (Z350). The restored teeth were scanned with micro-CT and the images were 3D reconstructed to evaluate the volumes and the distribution of the voids on the restoration-tooth interface of the gingival layer. The volume of the voids were statistically analyzed using nonparametric Jonckheere-Terpstra tests.
  
  
  RESULTS
  The volumes (mm(3)) of the voids on the restoration-tooth interface were: Z350F (0.000 15), F10 (0.000 39), F00 (0.012), Fuji (0.070), Z350 (0.16) and BF (0.20). There were significant differences between Z350F/F10 and Fuji/Z350/BF (P < 0.05). Most of the voids were found on the point-line angles of the cavities.
  
  
  CONCLUSIONS
  The voids on the restoration-tooth interface were mainly on the point-line angles of the cavities. Injectable materials with high flowablility could reduce the restoration-tooth interface voids significantly when used for the gingival layer in Class II restorations.
authors.affiliation: Department of Cariology and Endodontology, Peking University School and Hospital of Stomatology, Beijing 100081, China.
authors.forename: J
authors.initials: J
authors.lastname: Nie
authors.affiliation: Department of Cariology and Endodontology, Peking University School and Hospital of Stomatology, Beijing 100081, China.
authors.forename: X Y
authors.initials: XY
authors.lastname: Wang
authors.affiliation: Department of Cariology and Endodontology, Peking University School and Hospital of Stomatology, Beijing 100081, China.
authors.forename: X J
authors.initials: XJ
authors.lastname: Gao
mesh_terms: D001641:Bicuspid; D003188:Composite Resins; D003736:Dental Cavity Lining; D003763:Dental Leakage; D003764:Dental Materials; D003793:Dental Restoration, Permanent; D005881:Gingiva; D006801:Humans; D055114:X-Ray Microtomography
chemical_list: D003188:Composite Resins; D003764:Dental Materials; C533204:filtek Z350