Dentemp is not a material that I use; however, cementing a crown on an implant can be quite serious. The leading reason for implant failure is the presence of excess cement below the gumline. For that reason dentists have adopted a complicated cementing process that differs significantly from that of placing a crown on a natural tooth. You would be best off letting your dentist recement your crown. If it is an emergency, use the temporary cement, but only place a minuscule amount in the crown. You do not want to see any excess express around the gums.