Final answer:
The most common procedure for vital primary teeth is pulpotomy.
Step-by-step explanation:
The procedure most commonly used for vital primary teeth is Pulpotomy. A pulpotomy is a dental procedure that involves removing a portion of the pulp tissue from the crown of the tooth, while leaving the healthy pulp in the root intact. This procedure is performed to treat deep cavities or teeth that have been injured, and it helps to preserve the primary tooth until it naturally falls out.