A crown may be used in conjunction with a space maintainer. Although a crown can be fitted to a model of the prepared tooth, it is always better to furnish the lab with a prepared crown of your choice. As with the other unilateral space maintainers, an occlusal rest on the adjacent tooth will prevent unwanted mesial tipping of the molar. Note - When taking an impression for this appliance, it is best to take the impression with the crown in place. Then, pour the impression with the crown firmly seated in the impression.