In order to maintain the health of the tissue, beneath a pontic it is desirable to :
Gingival surface of pontic: 
• In order to maintain the health of the tissue beneath a pontic it is desirable to
— Have passive contact with ridge without blanching of the tissue.
— Have minimal tissue contact
• The gingival surface of a pontic should be concave buccolingually and convex mesiodistally.
• Highly glazed porcelain is the material of choice to contact with the ridge.
• Rough gingival surfaces accumulate plaque and cause irritation.
• Patients maintenance (flossing) is more important than the pontic design itself.
Have passive contact with the ridge without blanching of the tissue.
Patients' flossing is more important than the pontic design itself.
Highly glazed porcelain is the material of choice to contact with the ridge.
All of the above.