Which abutment is left hexed for 3-unit screw retained bridge?

If you use one hexed and one non hexed abutment for a screw-retained bridge, which one do you choose to be left hexed? Mesial one or distal one? or depending on the path of insertion and proximal surfaces of the adjacent teeth?

BroMike BroMike comments:

1. if I choose one hexed and one non hexed abutment for the screw retained bridge, I assume I should use one hexed and one non hexed open tray impression coping, correct?
  1. if I choose two non hexed abutments for the screw retained bridge, would it increase the impression accuracy if I use two hexed open tray impression copings rather than non-hexed?

  2. in what circumstances do we need to splint the open tray impression copings using the GC Pattern?

prosdoc. comments:

the key to a screw retained FPD is passivity. Therefore, it should be cemented intraorally. To do that, both abutments need to be hexed. Place the abutments then try in the bridge. once the occlusion and contacts have been worked out, cement one abutment with permanent cement. Remove the bridge with the one abutment cemented and cut off the hex. Replace the bridge and cement the second abutment (you cement them one at a time in case the hexes are not parallel). Remove the bridge and cut off the second hex. Then screw the bridge to place and torque the screws to their final value. you do not need to splint impression copings if they are pick up copings and you use a good stiff impression material (I use impregum)

BroMike BroMike comments:

screwmentable bridge with both hex cut off?

Prosdoc comments:


Rick CDT comments:

If you are going to leave one implant engaging, do it on the implant that is most parallel to the adjacent contacts. Based on the info given, Leave both non-engaging.