title: Evaluation of restorative materials using a new perfusion system.
abstract: OBJECTIVE
  1) To test a new perfusion device able to alternate demineralizing/nondemineralizing solutions, as an acid attack system, and 2) to standardize the dentin demineralization procedure, in order to define the in vitro secondary caries inhibiting potential of different restorative materials.
  
  
  METHODS
  A fluoride-containing adhesive/composite resin (group A), an experimental adhesive/composite resin (group B), and a glass-ionomer cement (group C) were used to restore 24 Class II cavities in extracted molars. Optimal conditions to obtain dentin demineralization inside the perfusion device were identified and applied to restored teeth. Dentin demineralization after perfusion was analyzed by microradiography. The output parameters were lesion morphology, dentin mineral volume percentage, and integrated mineral loss (Delta Z, % volume x microm) of the exposed (outer lesions) and marginal (inner lesions or caries inhibition zones, CIZs) dentin.
  
  
  RESULTS
  Demineralization increased as follows: group A < group B < group C. Group A behaved better than group B, probably due to fluoride content, as indicated by Delta-Z values, higher number of CIZs, and few inner lesions. Group C showed a marginal protective effect, demonstrated by the frequent CIZs and Delta-Z positive values. This effect, however, was unable to reduce the high demineralization, probably due to the critical handling characteristics, inducingthe worst marginal adaptation.
  
  
  CONCLUSIONS
  A new dynamic perfusion device was tested and a reproducible procedure was standardized in order to achieve in vitro conditions that could better simulate the pH changes of oral environment. A limited fluoride protective effect was demonstrated by using the perfusion system, whereas a perfect marginal adaptation was shown as a paramount factor to prevent restoration failure.
authors.affiliation: Laboratory for Pathophysiology of Orthopedic Implants, Rizzoli Orthopedic Institute, Bologna, Italy. lucia.savarino@ior.it
authors.forename: Lucia
authors.initials: L
authors.lastname: Savarino
authors.forename: Michelina
authors.initials: M
authors.lastname: Greco
authors.forename: Nicola
authors.initials: N
authors.lastname: Baldini
authors.forename: Armando
authors.initials: A
authors.lastname: Giunti
authors.forename: Mariantoinetta
authors.initials: M
authors.lastname: Pistone
authors.forename: Silvia
authors.initials: S
authors.lastname: Marchionni
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Breschi
authors.forename: Carlo
authors.initials: C
authors.lastname: Prati
mesh_terms: D002327:Cariostatic Agents / Q000008:administration & dosage; D003188:Composite Resins; D003720:Densitometry; D018772:Dental Marginal Adaptation; D003793:Dental Restoration, Permanent; D003804:Dentin / Q000737:chemistry; D005460:Fluorides, Topical / Q000008:administration & dosage; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008852:Microradiography; D010477:Perfusion / Q000295:instrumentation* / Q000379:methods; D019279:Resin Cements; D017001:Tooth Demineralization / Q000517:prevention & control*; D014089:Tooth Remineralization
chemical_list: D002327:Cariostatic Agents; D003188:Composite Resins; D005460:Fluorides, Topical; D019279:Resin Cements