Comparative Evaluation of Enhancing Retention of Dislodged Crowns Using Preparation Modifications and Luting Cements:...

Complete cast crowns are good alternatives and have best longevity for the restoration of damaged posterior teeth. Occasionally, a crown with clinically acceptable margins, preparation design, and occlusion becomes loose. Providers often debate whether such a crown can be successfully recemented with any degree of confidence that it will not be dislodged under normal masticatory function. It has been documented that resistance form increases by placing grooves opposing each other in a crown and tooth; cements also have a role to play in retention of crowns. To determine whether the addition of horizontal groove in the internal surface of the crown and/or tooth preparation will increase retention of the crowns, without remaking them and achieving better retention with cements.

A total of 80 extracted human mandibular molars were taken and standard preparation was done. After the crowns were ready, the groove was made in the internal surface of the crown and on the tooth, which were cemented with glass ionomer cement and resin cement. The tensile force needed to dislodge the crowns and teeth after cementation was found out.

The mean tensile force needed to dislodge the crown and tooth combination was highest for the group in which crown had a groove without any groove on the tooth and cemented using resin cement (252.60N).

It can be concluded from the study that it is best to recement a crown and tooth combination using resin cement where the crown has a groove, and the tooth has no groove.