title: Experimental primers containing synthetic and natural compounds reduce enzymatic activity at the dentin-adhesive interface under cyclic loading.
abstract: To evaluate the effect of experimental primers (chlorhexidine, enriched mixture of proanthocyanidins, and doxycycline) on the adhesive properties and gelatinolytic activity at dentin-resin interfaces of occlusal Class I restorations.
  
  
  
  The inactivation of enzymes by the experimental primers was assessed by fluorescence assay and gelatin zymography. To assess the adhesive properties, occlusal Class I cavities were prepared in sound human molars, etched with phosphoric acid and restored with one of the primers and an etch-and-rinse adhesive system (Adper Single Bond Plus-3M ESPE). After the restorative procedures, specimens were divided into two subgroups (n=6) consisting of storage in incubation buffer or axial cyclic loading at 50N and 1,000,000 cycles. Then, the specimens were sectioned and slices were assigned to in situ zymography assay and microtensile bond strength (TBS) test.
  
  
  
  Fluorescence assay and gelatin zymography revealed that the experimental primers inactivated rMMPs. In situ zymography (2-way ANOVA, Tukey, p<0.05) showed that cyclic loading increased the gelatinolytic activity at the resin-dentin interface and the experimental primers decreased the gelatinolytic activity at the adhesive interface. The experimental primers had no significant effects on dentin-adhesive bond strengths with or without cyclic loading (2-way ANOVA, p>0.05).
  
  
  
  The use of experimental primers impaired the enzymatic activity at the dentin-adhesive interface after cyclic loading and the activity of rMMPs. Cyclic loading did not have a significant effect on the bond strength.
authors.affiliation: Department of Restorative Dentistry, College of Dentistry, University of Illinois at Chicago, IL, USA; Department of Dental Materials and Prosthodontics, Ribeirão Preto Dental School, University of São Paulo, SP, Brazil.
authors.forename: Ana Beatriz
authors.initials: AB
authors.lastname: Silva Sousa
authors.affiliation: Department of Restorative Dentistry, College of Dentistry, University of Illinois at Chicago, IL, USA.
authors.forename: Cristina M P
authors.initials: CMP
authors.lastname: Vidal
authors.affiliation: Department of Restorative Dentistry, College of Dentistry, University of Illinois at Chicago, IL, USA.
authors.forename: Ariene Arcas
authors.initials: AA
authors.lastname: Leme-Kraus
authors.affiliation: Department of Dental Materials and Prosthodontics, Ribeirão Preto Dental School, University of São Paulo, SP, Brazil.
authors.forename: Fernanda C P
authors.initials: FCP
authors.lastname: Pires-de-Souza
authors.affiliation: Department of Restorative Dentistry, College of Dentistry, University of Illinois at Chicago, IL, USA. Electronic address: bedran@uic.edu.
authors.forename: Ana K
authors.initials: AK
authors.lastname: Bedran-Russo
mesh_terms: D000134:Acid Etching, Dental; D003188:Composite Resins; D001840:Dental Bonding; D003738:Dental Cements; D003804:Dentin; D017220:Dentin-Bonding Agents; D006801:Humans; D008422:Materials Testing; D019279:Resin Cements; D013718:Tensile Strength
chemical_list: D003188:Composite Resins; D003738:Dental Cements; D017220:Dentin-Bonding Agents; D019279:Resin Cements
keywords: Adhesion; Chlorhexidine; Cross-linking agent; Cyclic loading; Dentin; Doxycycline; Enzymatic activity; In situ zymography; Matrix metalloproteinases; Proanthocyanidins