Objective: Retrievability of prostheses is necessary when restoring osseointegrated implants with cemented castings.  The purpose of this study was to compare the tensile bond strength (TBS) of provisional luting agents used to cement metal castings (IS-64, Ivoclar) to pre-fabricated implant abutments (HL series #2235 lot 954516, Steri-Oss).  Methods:  TempBond (Kerr) served as the control.  10 implant abutments were attached to implant analogs secured in acrylic resin blocks.  10 gold 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.  All specimens were stored in distilled water at 37ēC for 48hr before testing on an Instron machine with a load of 500kg at a crosshead speed of 0.5 cm/min.  Results: One-way ANOVA (α=0.05) revealed a significant difference between materials.  Similar values are denoted by letters as shown by Scheffe's analysis (α=0.05).

Provisional Cement	Type of Cement	Mean (MPa)	SD	SEM
Zone (Cadco)	Non-Eugenol	0.40	0.12	0.04
Temp Bond (Kerr)	Eugenol	1.28A	0.24	0.08
Provilink (Ivoclar)	Resin	1.31A	0.34	0.11
Embonte (Cadco)	Eugenol	1.33A	0.29	0.09
Temp Bond Clear (Kerr)	Resin	1.48A	0.19	0.06
ImProv w/ vaseline (Steri-Oss)	Resin	2.07B	0.28	0.09
Temp Bond NE (Kerr)	Non-Eugenol	2.14B	0.34	0.11
ImProv  (Steri-Oss)	Resin	2.17B	0.17	0.05
IRM (Caulk/Dentsply)	Eugenol	2.95C	0.41	0.13
Neo-Temp w/ releasing agent(Teledyne)	Resin	3.04C	0.23	0.07
Neo-Temp (Teledyne)	Resin	4.08	0.32	0.10

Conclusion:  The TBS of Zone was statistically lower than that of the other cements.  Neo-Temp had the highest TBS, and was approximately three times stronger than Temp Bond.  The type of cement did not significantly impact the TBS.