title: Shear bond strength of self-etch adhesives to enamel with additional phosphoric acid etching.
abstract: This study evaluated the shear bond strength of self-etch adhesives to enamel and the effect of additional phosphoric acid etching. Seventy sound human molars were randomly divided into three test groups and one control group. The enamel surfaces of the control group (n=10) were treated with Syntac Classic (SC). Each test group was subdivided into two groups (each n=10). In half of each test group, ground enamel surfaces were coated with the self-etch adhesives AdheSe (ADH), Xeno III (XE) or Futurabond NR (FNR). In the remaining half of each test group, an additional phosphoric acid etching of the enamel surface was performed prior to applying the adhesives. The shear bond strength was measured with a universal testing machine at a crosshead speed of 1 mm/minute after storing the samples in distilled water at 37 degrees C for 24 hours. Fracture modes were determined by SEM examination. For statistical analysis, one-way ANOVA and the two-sided Dunnett Test were used (p>0.05). Additional phosphoric etching significantly increased the shear bond strength of all the examined self-etch adhesives (p<0.001). The highest shear bond strength was found for FNR after phosphoric acid etching. Without phosphoric acid etching, only FNR showed no significant differences compared to the control (SC). SEM evaluations showed mostly adhesive fractures. For all the self-etch adhesives, a slight increase in mixed fractures occurred after conditioning with phosphoric acid. An additional phosphoric acid etching of enamel should be considered when using self-etch adhesives. More clinical studies are needed to evaluate the long-term success of the examined adhesives.
authors.affiliation: Department of Conservative Dentistry, Periodontology and Preventive Dentistry, Hannover Medical School, Hannover, Germany. Luehrs.Anne-Katrin@mh-hannover.de
authors.forename: Anne-Katrin
authors.initials: AK
authors.lastname: Lührs
authors.forename: Silke
authors.initials: S
authors.lastname: Guhr
authors.forename: Reinhard
authors.initials: R
authors.lastname: Schilke
authors.forename: Lothar
authors.initials: L
authors.lastname: Borchers
authors.forename: Werner
authors.initials: W
authors.lastname: Geurtsen
authors.forename: Hüsamettin
authors.initials: H
authors.lastname: Günay
mesh_terms: D000134:Acid Etching, Dental / Q000379:methods*; D000180:Acrylic Resins / Q000737:chemistry; D000268:Adhesiveness; D003188:Composite Resins / Q000737:chemistry; D001840:Dental Bonding; D003743:Dental Enamel / Q000648:ultrastructure*; D003799:Dental Stress Analysis / Q000295:instrumentation; D017220:Dentin-Bonding Agents / Q000737:chemistry*; D006801:Humans; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry; D008855:Microscopy, Electron, Scanning; D010756:Phosphoric Acids / Q000737:chemistry*; D019279:Resin Cements / Q000737:chemistry; D033081:Shear Strength; D013314:Stress, Mechanical; D013499:Surface Properties; D013696:Temperature; D013997:Time Factors; D014867:Water / Q000737:chemistry
chemical_list: D000180:Acrylic Resins; C489662:AdheSE cement; C520091:CeramX; D003188:Composite Resins; D017220:Dentin-Bonding Agents; D008689:Methacrylates; D010756:Phosphoric Acids; D019279:Resin Cements; C078484:Syntac dentine adhesive; C501891:Tetric EvoCeram; C487957:Xeno III; C512545:futurabond NR; D014867:Water; C030242:phosphoric acid