Objective: The purpose of this study was to evaluate the tensile bond strength (TBS) of  provisional cements used to retain gold castings (IS-64, Ivoclar) to pre-fabricated implant abutments (HL series #2235 lot 954516, Steri-Oss) over time. Methods:  TBS was tested at 2, 5, and 10 days. TempBond served as the control.  10 implant abutments were attached to implant analogs secured in acrylic resin blocks.  10 castings were made from a 0.025 mm spaced die and each was randomly paired with one of 10 abutments.  Each casting was cemented with each of the cements.  Castings were heated to 600ēC for 1.5hr, bench cooled, then cleaned in an ultrasonic cleaner for 30 minutes to remove cement.  Specimens were stored in distilled water at 37ēC before testing on an Instron machine with a load of 500kg at a crosshead speed of 0.5 cm/min. Results:  ANOVA and Scheffe's analysis (α =0.05) revealed differences within times (letters denote similar values) and over time.  TempBondNE and TempBond Clear showed significantly less TBS over time between 2 and 10 day data.

Conclusion:  TBS of all materials degraded after 10 days.  TempBondNE showed the greatest TBS decrease (58%) while ImProv demonstrated the least TBS loss after 10 days (4%).