Journal of Dental Research, Vol 61, 400-402, Copyright © 1982 by International & American Associations for Dental Research Online Journals
Slots vs pins: a comparison of retention under simulated chewing stresses
W. C. Outhwaite, S. W. Twiggs, C. W. Fairhurst and G. E. King
The specimens of composite resin retained by pins exhibited significantly
lower cycle life than did all other groups. At low loads, the pins and
slots are comparable (when composite resin is used), but there is a
dramatic decrease in the life of restorations retained with pins as the
load is increased. At the 30-micrometer end point, the composite
restorations retained with pins failed at a mean of 250 cycles, whereas the
composite restorations retained with a slot failed at 250,000 cycles - a
1000X increase in cycle life. In general, cycle life of composite resin
retained with a slot is comparable to or greater than that of amalgam
retained with a slot or pins. Whether the life difference between the pin-
and slot- retained amalgam restoration is clinically significant is not
known; however, the baseline for a clinical study of the two types of
retention for definitive amalgam restorations has been completed and will
be reported in the future.
