implants - international magazine of oral implantology

I industry report _ CAD/CAM bar restoration _Conventional or CAD/CAM?Today,dentaltech- nicians and implantologists ponder this question morefrequentlythanever.Moreandmoreoften,they tend towards CAD/CAM. Owing to their tension-free fit, CAD/CAM-fabricated solutions are particularly well suited for the restoration of larger jaw sections. Deciding in favour of or against a CAD/CAM restora- tion should thus always be a team decision. With his expertise and training, the dental technician is able to contribute considerably to an aesthetic and techni- cally perfect result. Toensuresuccessfulprostheticrestorations,allthe stepsofaprocedure—fromplanningthroughimpres- sion to insertion—need to be performed with utmost care. This is equally true for both conventionally cast work and CAD/CAM-fabricated structures. With both methods, only a precise transfer of the oral situation to the model guarantees success. Precision is vital for both methods, particularly when restoring larger jaw sections. Outstanding results can also be obtained with conventional casting technology if the work is doneaccuratelyandwithsufficientexperience.How- ever, the risk of an ill fit is substantially higher com- pared with modern CAD/CAM procedures. Further- more, wide-spanning and solid frameworks in partic- ular enable cavities to arise and the framework to warp. Also, (partial) overheating of the melt, another potentialqualityflaw,isoftenobservedwithlargevol- umes. These problems do not occur with CAD/CAM technology. _Therapy decision Ourpatientwishedtoregainafirmbiteandunim- paired speech. She had already been wearing mu- cosa-supported complete dentures for 20 years, but wascomfortableonlywiththemaxillarydenture.The grip of the mandibular prosthesis was inadequate owing to the resorbed alveolar ridge (Fig. 1) and ob- Passive fit—for the first time CAD/CAM bar restoration Author_Björn Roland & Dr Peter Gehrke, Germany 24 I implants3_2011 Fig. 1 Fig. 2 Fig. 1_The panorama image shows the situation prior to insertion of the XiVE S implants. Fig. 2_Two weeks after being uncovered, an open pick-up impression is made at implant level with an individual tray. Fig. 3_In order to check the accuracy of transfer, a bar made from autopolymerisate is manufactured on a screwed-in Friadent MP abutment and split into segments. Fig. 4_The individual tray for the pick-up impression with fixed pick-up screws. Fig. 3 Fig. 4