title: Does inhibition of proteolytic activity improve adhesive luting?
abstract: Endogenous enzymes may be involved in the biodegradation of adhesive restoration-tooth interfaces. Inhibitors of matrix metalloproteinases (MMPs) have been suggested to retard the bond-degradation process. Limited data are available on whether composite cements may also benefit from MMP inhibitors. Therefore, the aim of this study was to determine the effect of two MMP inhibitors--chlorhexidine digluconate (CHX) and galardin--on the microtensile bond strength (μTBS) of two self-adhesive composite cements to dentin. Ceramic specimens were cemented to bur-cut dentin surfaces using the self-adhesive composite cements RelyX Unicem 2 (3M ESPE) or Clearfil SA (Kuraray), or the etch-and-rinse composite cement Nexus 3 (Kerr) that served as the control. The surfaces were left untreated or were pretreated with MMP inhibitors (2% CHX or 0.2 mM galardin). The μTBS was determined 'immediately' and upon ageing (water storage for 6 months). Statistical analysis revealed a significant effect of the factors 'composite cement' and 'storage', as well as all interactions, but no effect of the MMP inhibitors. After 6 months of ageing, the μTBS decreased for all cements, except for the multistep etch-and-rinse luting composite when it was applied without MMP inhibitors. The MMP inhibitors could not prevent the decrease in μTBS upon ageing and therefore do not improve the luting durability of the composite cements tested.
authors.affiliation: KU Leuven-BIOMAT, Department of Oral Health Sciences, KU Leuven (University of Leuven), & Dentistry, University Hospitals Leuven, Leuven, Belgium. luehrs.anne-katrin@mh-hannover.de
authors.forename: Anne-Katrin
authors.initials: AK
authors.lastname: Lührs
authors.forename: Jan
authors.initials: J
authors.lastname: De Munck
authors.forename: Werner
authors.initials: W
authors.lastname: Geurtsen
authors.forename: Bart
authors.initials: B
authors.lastname: Van Meerbeek
mesh_terms: D003188:Composite Resins / Q000737:chemistry*; D001840:Dental Bonding / Q000379:methods*; D003799:Dental Stress Analysis; D006801:Humans; D008422:Materials Testing; D061965:Matrix Metalloproteinase Inhibitors / Q000737:chemistry*; D008964:Molar, Third; D019279:Resin Cements / Q000737:chemistry*; D013718:Tensile Strength
chemical_list: D003188:Composite Resins; D061965:Matrix Metalloproteinase Inhibitors; D019279:Resin Cements