Study of the retention of pins

The retention of cemented and threaded pins was examined. The cemented pins were serrated and plain and the cements used were: (1) ZOE, (2) zinc phosphate, (3) glass ionomer, and (4) polycarboxylate. The decisive factors for the retention of the cemented pins were the types of cements and the external morphology of the pin. The threaded pins of the same diameter and the same depth as those of the cemented pins possessed approximately three times greater retention.