Posterior Quadrant Reconstruction With a Natural Tooth Abutment And the IMZ Implant

This cross-sectional schematic diagram illustrates the internal relationship of the implant components.

Components include from left: titanium screw and intramobile element for 4.0 mm diameter fixture; titanium screw and intramobile element for 3.3 mm diameter implant; 4.0 mm impression post; 2.0 mm impression post with model replica; impression post and model replica for 3.3 mm diameter implant.

From left: 4.0 mm implant cylinder; second phase healing screw; titanium healing screw; placement head; titanium transmucosal exten

sion; and intramobile e1ement(IME).

This shows the implant uncovered and ready for placement of trans-mucosal extension and intramobile element.

The impression post is shown screwed into place.

A full arch view of the master impreion with mudel replica attached

The distal view illustrates the impression post with the model replica properly placed back into position.

The master cast is poured and the laboratory IME is screwed into the fixture replica.

The maxillary and mandibular casts are articulated.

The occlusal height dictated by the master casts is used to correctly adjust the length of the titanium screw, the plastic waxing sleeve, and the tube and screw attachment.

The height of the waxing sleeve is reduced by removing the desired length from the middle of the sleeve. This technique maintains the preformed ends which fit the neck of the screw and the head of the 1MB. The two halves are then reattached with DuraLay resin and the component design is completed.

The tube and screw attachment (Cendres and Metaux, Sterngold) incorporates a fer-rule which has a precision fit with the head of the screw and the rim of the tube. The integrity of these components is essential to the success of the bridge.

The attachment is placed at the distal of the bicuspid abutment. It should be parallel to the path of insertion of the implant screw. The coping is waxed with the attachment enveloped in a cast position. The wax pattern is designed with an extracoronal block which has walls with a five degree taper. A surveying table or similar device is used to check the degree of taper on the three outside walls, ensuring the fit and draw of the overcasting.

The pattern is fitted with a special casting screw to maintain the threads of the female tube. It is then sprued up and invested in a high heat phosphate investment. The casting ring is burned out, cast in a noble alloy (Naturelle, Jeneric/Pentron) and allowed to bench cool.

The casting is carefully devested and fitted to the bicuspid die. The extracoronal block is then polished. The secondary component containing the plastic waxing sleeve and screw is now fabricated.

The extracoronal block is coated with lubricant and the ferrule is put to place with the screw. A resin shell is formed around the ferrule and the entire extracoronal block. Using resin, the balance of the connection is finished between the waxing sleeve and the resin-coated block. Final contours are waxed, the pattern is sprued up, invested, and cast in a noble alloy. The casting is devested and fitted precisely to the implant replica and extracoronal block. The two-piece assembly is now ready

The schematic diagram illustrates all components and crown contours in correct harmony. Note the fixing screw adjusted slightly out of occlusion. The tip of the screw reaches the recommended depth inside the IME.

The metal frame is degassed, and opaque is applied in two stages. The gingival and incisal porcelains are now blended, with particular care being taken to keep the screw holes clean and free of porcelain. Note the shape and contour of all finish lines.

All porcelain work is completed. The three-unit bridge is tried in and the occlusion is adjusted.

After a final glaze and polish, the bridge assembly is complete.