CAD0111

I 25 industry report _ CAD/CAM bar restoration I CAD/CAM 1_2011 on two implants, which would be more economical, was not an alternative from a medical perspective. The patient desired as stable a restoration as possi- ble and we had to avoid degradation of the implant site through tilting motions in each case. In the current case, the precision, which can only be achieved with this procedure, turned the balance in favour of a CAD/CAM-produced bar construction. This is also the reason that our dental laboratory, whenever possible, uses wide-span superstructures that are fabricated industrially. The result becomes ultra-predictable in conjunction with the two-stage impression process that we have been implementing with a conventionally cast framework for years. We frequentlyusethetwo-stagemethodwheneverthere are high demands on accuracy of the impression. _Transfer of implant positions Fourmonthsafterinsertion,theosseointegrated implants (XiVE S, length: 13 mm; diameter: distal 4.5 mm, mesial 3.8 mm) were restored with gingiva formers. The situation was impressed and an indi- vidual tray created. The impression at implant level was made two weeks after uncovering (Fig. 2). The DENTSPLY Friadent pick-up transfer copings were then screwed onto the analogues in the dental lab- oratory. Precisely transferring the oral situation with the abutments onto the model requires a sec- ond impression with an appropriate control key. Abarmadefromautopolymerisatewasusedforthis. In order to reconcile any tensions, which develop during polymerisation, the bar is divided into four parts (Fig. 3). We went on to make a second individ- ual tray (Fig. 4) and a plastic-based template to de- terminetherelation.Wedesignedthetemplateinsuch a way that it can be secured with two impression copingsontotheFriadentMPabutments(DENTSPLY Friadent) fixed in the mouth (Fig. 5). This is the only waytotestthebitereliably,aswellastheaesthetics, function and phonetics during the later wax-up. During the session to determine the relation, an impression was also made at gingiva level using the plasticbar.Theindividualpartswerescrewedonthe Fig. 5_The bite template is fixed in the mouth on two implants. Fig. 6_Preparation for pick-up impression: The four separate parts of the bar are screwed-in in the mouth. Fig. 7_The segments are splinted with a small amount of autopolymerisate. The Friadent MP abutments are not removed afterwards. Fig. 8_Double-mix impression. Fig. 9_The master cast with removable gingiva mask. Fig. 10_The wax-up. Fig. 6 Fig. 10 Fig. 5 Fig. 8Fig. 7 Fig. 9