title: Temperature and humidity effects on bond strength of a dentinal adhesive.
abstract: Dentin specimens from 46 extracted human molar teeth were used in a matched-pair design examining the factors of temperature/humidity on shear bond strength of a dentinal adhesive to dentin. For one tooth-half, all procedures using restorative materials were accomplished in a controlled temperature and humidity chamber (humidity 95.0 +/- 2.0%, temperature 37.0 +/- 0.3 degrees C). For the other matched tooth-half all procedures were performed at ambient room conditions (humidity 52%, temperature 23.3 degrees C/74 degrees F). Oil-free air and water were used in all restorative procedures. Application of Scotchbond Multi-Purpose Adhesive System was followed by placement of Z100 Restorative Resin, and thermocycling 1000 cycles from 5 to 55 degrees C. Each matched specimen was tested 24 hours later in an Instron Testing Machine. A paired t-test was performed for comparison of bond strength set values, since they were obtained from matching halves of the same teeth. Paired t-test comparison showed that the average humidity/temperature chamber mean of 7.14 +/- 3.12 MPa was significantly less than the ambient conditions mean of 14.29 +/- 5.07 (P = 0.0000). Bond strength testing under simulated oral conditions may produce significantly different findings than customary bench-top laboratory experiments.
authors.affiliation: University of Minnesota, School of Dentistry, Biomaterials Research Center, Minneapolis 55455, USA.
authors.forename: G P
authors.initials: GP
authors.lastname: Nystrom
authors.forename: J R
authors.initials: JR
authors.lastname: Holtan
authors.forename: R A
authors.initials: RA
authors.lastname: Phelps
authors.forename: W S
authors.initials: WS
authors.lastname: Becker
authors.forename: T B
authors.initials: TB
authors.lastname: Anderson
mesh_terms: D003188:Composite Resins; D003793:Dental Restoration, Permanent / Q000379:methods; D017220:Dentin-Bonding Agents / Q000737:chemistry*; D006801:Humans; D006813:Humidity; D016555:Matched-Pair Analysis; D008422:Materials Testing; D019279:Resin Cements / Q000737:chemistry*; D012822:Silicon Dioxide; D013696:Temperature; D013718:Tensile Strength; D015040:Zirconium
chemical_list: D003188:Composite Resins; D017220:Dentin-Bonding Agents; D019279:Resin Cements; C084018:Scotchbond Multi-Purpose; C083568:Z100 composite resin; D012822:Silicon Dioxide; D015040:Zirconium