I need to properly store a 2 unit nesbit following implants. Made out of acrylic or plastic with no metal clasps. Do not want it to split if gets dry?

Store in water. Store in water and change the water daily to prevent bacterial growth. Clean and wash the denture daily as well.
Water and Vinegar. Store the nesbit overnight in water, adding half of a teaspoon of white vinegar will help keep them clean and odor free.
Moisture. Keep it wet. Cover with water, drop in a denture cleaning tablet. Change water and put in new tablet daily.