title: Effect of tooth age on microtensile bond strength of two fluoride-releasing bonding agents.
abstract: OBJECTIVE
  The purpose of this study was to evaluate the effect of age of dentin and enamel on the microtensile bond strengths of a glass-ionomer based, all-in-one, single-step, self-etching adhesive system (Reactmer Bond, RB) and an antibacterial, two-step self-etching primer system (ABF Bond, ABF).
  
  
  METHODS
  Extracted molars from 3 age groups (20 to 25, 35 to 40, and 50 to 55 years) were used. Enamel was removed from the occlusal surfaces of the teeth, and the entire flat surfaces were covered with composite resin (4 mm in height) following application of bonding agents. The bonded specimens were thinly sectioned parallel to the long axis of the tooth into 0.87 +/- 0.03 mm2 rectangular sections, resulting in 6 to 7 enamel specimens and 10 to 15 dentin specimens per tooth. The specimens were subjected to the microtensile test at a crosshead speed of 1 mm/min. The data were analyzed by Univariate ANOVA, Tukey HSD, and regression analysis.
  
  
  RESULTS
  The bond strength of ABF to both enamel and dentin was higher than the bond strength of RB. Bond strengths of ABF to dentin were significantly higher than the bond strengths to enamel (p < 0.05). The 35- to 40-year age group of ABF showed the highest bond strength of all. In RB dentin groups, 34% of specimens showed cohesive failure in composite resin material.
  
  
  CONCLUSIONS
  Bond strength values to enamel were not affected by age of teeth in either bonding system. Dentinal bond strength using ABF changed according to age of the teeth. Age did not affect bond strength values of RB to dental hard tissues. However, the high number of cohesive failures in Reactmer paste indicated low tensile strength of the material.
authors.affiliation: Selcuk University, Faculty of Dentistry, Department of Operative Dentistry, Konya, Turkey. fozer@selcuk.edu.tr
authors.forename: Füsun
authors.initials: F
authors.lastname: Ozer
authors.forename: Abdulkadir
authors.initials: A
authors.lastname: Sengun
authors.forename: Bora
authors.initials: B
authors.lastname: Ozturk
authors.forename: Esra Can
authors.initials: EC
authors.lastname: Say
authors.forename: Junji
authors.initials: J
authors.lastname: Tagami
mesh_terms: D000268:Adhesiveness; D000328:Adult; D000375:Aging / Q000473:pathology*; D003188:Composite Resins / Q000737:chemistry; D001840:Dental Bonding; D003743:Dental Enamel / Q000033:anatomy & histology*; D003799:Dental Stress Analysis / Q000295:instrumentation; D003804:Dentin / Q000033:anatomy & histology*; D005899:Glass Ionomer Cements / Q000737:chemistry*; D006801:Humans; D008422:Materials Testing; D008875:Middle Aged; D019279:Resin Cements / Q000737:chemistry*; D013314:Stress, Mechanical; D013499:Surface Properties; D013718:Tensile Strength
chemical_list: C504139:ABF Bond; D003188:Composite Resins; D005899:Glass Ionomer Cements; D019279:Resin Cements; C447779:reactmer bond; C465006:reactmer paste