title: Enamel-dentin crown fractures bonded with various bonding agents.
abstract: A method is described, by which the fracture strength of bonded, previously fractured incisors can be measured. The study employed incisors from sheep, which could be obtained in suitable numbers and with limited variation in size. The incisors were fractured parallel to the incisal edge. The mean fracture area +/- SD of central incisors was 8.45 +/- 0.89 mm2 and of lateral incisors 6.50 +/- 0.64 mm2. The enamel area constituted about 30% of the total fracture area. Acid etching of the enamel and bonding of the fractures with an unfilled resin yielded a fracture strength, which was approximately 38% of the fracture strength of fractured teeth restored with acid etching of enamel, Gluma treatment of dentin and bonding with the unfilled resin. Teeth restored in this way, but using the dentin bonding agent Tenure or Scotchbond2 instead of Gluma, exhibited mean fracture strengths which were not significantly different from that obtained when Gluma was employed as the bonding agent. The mean fracture strength by using one of the three bonding agents in combination with acid etching of enamel was about 8 MPa, which is approximately 50% of the fracture strength of intact teeth.
authors.affiliation: Department of Dental Materials and Technology, University Hospital (Rigshospitalet), Copenhagen, Denmark.
authors.forename: E C
authors.initials: EC
authors.lastname: Munksgaard
authors.forename: L
authors.initials: L
authors.lastname: Højtved
authors.forename: E H
authors.initials: EH
authors.lastname: Jørgensen
authors.forename: J O
authors.initials: JO
authors.lastname: Andreasen
authors.forename: F M
authors.initials: FM
authors.lastname: Andreasen
mesh_terms: D000134:Acid Etching, Dental; D000818:Animals; D001840:Dental Bonding; D003738:Dental Cements; D003799:Dental Stress Analysis; D005976:Glutaral; D008422:Materials Testing / Q000379:methods; D009566:Nitrates; D017942:Nitric Acid; D010070:Oxalates; D011109:Polymethacrylic Acids; D019279:Resin Cements; D012756:Sheep; D013718:Tensile Strength; D014082:Tooth Fractures
chemical_list: D003738:Dental Cements; D009566:Nitrates; D010070:Oxalates; D011109:Polymethacrylic Acids; D019279:Resin Cements; C061140:Tenure Dentin Conditioner; D017942:Nitric Acid; C041330:Scotchbond; C044372:Gluma; D005976:Glutaral