title: Dental fracture fragment attachment: fracture model and luting agent comparisons.
abstract: OBJECTIVE
  The purpose of this study was twofold: 1. To compare two different research models for simulating a traumatic anterior tooth fracture: the blunt trauma method (standard method) and an AL2O3 sectioning method (experimental method). 2. To compare the bond strength of tooth fragments bonded with resin modified glass ionomer vs. a light cured composite resin.
  
  
  METHODS
  Two hundred bovine incisors were used in the study and kept in plain tap water throughout. The study consisted of five basic steps: 1. Fracture of the teeth by either blunt trauma (chisel and hammer) or AL2O3 sectioning disc. 2. Luting of the fractured fragments back to the teeth using either a composite resin or resin modified glass ionomer. 3. Thermocycling of the repaired teeth. 4. Dislodging the teeth to determine the strength of repair. 5. Determination of fracture type.
  
  
  RESULTS
  One-way ANOVA revealed a statistically significant difference in the forces required to fracture the resin modified glass ionomer and composite resin regardless of whether the teeth were originally fractured with the blunt force method (p=0.030) or the disc sectioning method (p=.001). One-way ANOVA also revealed a statistically significant difference between the forces required for fracture by blunt trauma and the disc fracture techniques with the resin modified glass ionomer group (p=0.000345). However, there was no significant difference when the two techniques were compared for the composite resin (p= 0.2941).
  
  
  CONCLUSIONS
  1. The resin modified glass ionomer was significantly stronger than the composite resin when both the blunt trauma and the disc fracture techniques were employed. 2. The study's results do not support substituting the ease of the AL2O3 disc for the more time-consuming blunt trauma method.
authors.affiliation: Department of Oral Facial Development, Indiana University School of Dentistry, Riley Hospital for Children, Indianapolis, USA.
authors.forename: Jeffrey A
authors.initials: JA
authors.lastname: Dean
authors.forename: George
authors.initials: G
authors.lastname: Bullard
authors.forename: Robert W
authors.initials: RW
authors.lastname: Long
authors.forename: B Keith
authors.initials: BK
authors.lastname: Moore
authors.forename: Shelley M
authors.initials: SM
authors.lastname: McDonald
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D002417:Cattle; D001840:Dental Bonding / Q000379:methods*; D003793:Dental Restoration, Permanent / Q000379:methods; D003799:Dental Stress Analysis; D017220:Dentin-Bonding Agents / Q000627:therapeutic use; D005899:Glass Ionomer Cements / Q000627:therapeutic use; D007180:Incisor / Q000293:injuries; D008422:Materials Testing; D019279:Resin Cements / Q000627:therapeutic use; D014082:Tooth Fractures / Q000628:therapy*
chemical_list: D017220:Dentin-Bonding Agents; D005899:Glass Ionomer Cements; D019279:Resin Cements; C065770:Herculite XR; C084541:Fuji glass-ionomer lining cement