title: Pilot study of the effects of three bonding systems on the torsional resistance of a titanium-reinforced composite core.
abstract: BACKGROUND
  There are no studies analyzing the effects of a bonding agent on torsional resistance for a titanium-reinforced core material bonded with a multistep bonding system.
  
  
  OBJECTIVE
  This pilot study investigated the effects of multistep bonding agents on torsional resistance of a titanium-reinforced composite core material (Ti-Core core material).
  
  
  METHODS
  A total of 40 recently extracted human molars with their crowns removed were placed into acrylic resin blocks and divided into 4 groups of 10 specimens. Only multistep bonding systems were used (AllBond-2, ScotchBond Multi-
  
  
  OBJECTIVE
  Tenure A&B, and the control without bonding agent). Specimens were prepared according to manufacturer's instructions. The control group was etched with a 37.5% phosphate acid. All cores were fabricated with Ti-Core titanium core material with No. 1 hard copper bands as the matrix. Ti-Core core material was applied and allowed to cure for 1 hour, then the cores were placed in 100% humidity (water) for 1 week. Test specimens were placed in a special jig and a clockwise torsional force applied. Torsional force was measured on a Lebow 1102-200 torque transducer and recorded on a Hewlett Packard 7015B X-Y recorder in inch x ounce then converted into Newton-meter. One-way analysis of variance (ANOVA) was used to test for statistical significance (P <.05).
  
  
  RESULTS
  Torsional values (Newton-meter) were AllBond-2, 0.1980, ScotchBond Multi-
  
  
  OBJECTIVE
  0.1890, Tenure A&B, 0.2142; the control group recorded a value of zero. Statistical analysis revealed that bonding systems did not differ from one another.
  
  
  CONCLUSIONS
  Use of a bonding agent increased the core's resistance to torsional forces. Lack of a bonding agent dramatically reduced the resistance to torque.
authors.affiliation: Essential Dental Laboratories, South Hackensack, NJ 07606, USA.
authors.forename: B I
authors.initials: BI
authors.lastname: Cohen
authors.forename: M K
authors.initials: MK
authors.lastname: Pagnillo
authors.forename: B L
authors.initials: BL
authors.lastname: Musikant
authors.forename: A S
authors.initials: AS
authors.lastname: Deutsch
authors.forename: G
authors.initials: G
authors.lastname: Cofrancesco
mesh_terms: D000704:Analysis of Variance; D003188:Composite Resins / Q000737:chemistry; D003799:Dental Stress Analysis; D017220:Dentin-Bonding Agents; D006801:Humans; D008422:Materials Testing; D008689:Methacrylates; D010865:Pilot Projects; D011176:Post and Core Technique; D019279:Resin Cements; D014025:Titanium; D019415:Torque
chemical_list: D003188:Composite Resins; D017220:Dentin-Bonding Agents; D008689:Methacrylates; D019279:Resin Cements; C084018:Scotchbond Multi-Purpose; C074811:Tenure adhesive; C079578:Ti-Core composite resin; C100742:All-Bond 2; D014025:Titanium