For multiple anterior implants the Essix appliance is the best way to temporize.  It alleviates tissue pressure and can even have an ovate shape to it to help train the gingival tissues from the start.  

I recently had my assistant make a modification to the traditional Essix appliance to give better esthetics.

What we did was take a thicker thermal plastic material and made a suck down off the diagnostic wax up. Then the teeth were built on the internal with composite. The facial area is cut away and the lingual area has holes to help retain the composite. Bonding agent can also used to help adhere the composite to the plastic matrix. 

The advantage of this type of Essix appliance is that it gives a much nicer esthetic appliance for the patient to wear during the healing phase of implant therapy.