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I 19 case report _ ceramic bridge I CAD/CAM 2_2010 captured,thetemporarywasremovedandtitanium dioxide was sprayed onto the abutments once again. We then used the CEREC Bluecam to capture the abutments (Fig. 2). The bridge we wanted to copy virtually over- lapped the prepared model. The gold colour model underneath was the original prepared image and the grey image on top was the correlation model. It was evident that the model matched from the speckledlooktothegreymodel,asitperfectlyover- lapsthepreparedmodel.Weneedthiskindofspeck- ledlooktooccurbecausethereisa20°pitchandroll yee and yaw of the camera in order to match up the images. Although the CEREC software merges the imagesthisdoesnotmeanthattheimageswillcor- relate 100 %. The correlation may thus be reduced even though we have a virtual model (Fig. 3). When using the correlation design technique, one can draw the margin starting with any one of the abutments. Simply start to draw the margin close to the interproximal. As one draws around the preparation, do not close the loop on the prepara- tion on which you started. Continue to draw the margin out onto the tissue, thus creating a second margin on the imaginary pontic area. Continue on to the next abutment, draw around the next abut- ment, then continue back onto the tissue to con- tinue the lingual margin of the pontic. Finally, join the rest of the margin to the original abutment to close the loop. Once the loop has been completed, onecancarryontothenextwindow.Inthisway,we fool the CEREC software into thinking this pontic loop is one crown (Fig. 4). Figure 5 shows our completed bridge that was milledusingtheVITAForteblock,whichisnotaplain monochromatic block. The final result will have a natural gradient built into it when completed, as it is has four colour steps to it (Fig. 5). In order to achieve the proper shading for our ceramic, I used Quick Match (Hankins Laboratories), whichcanbeusedtomimicthestumpshadevalueof theabutments(Fig.6).Next,IusedtheIvoclarStump ShadeGuidetomatchtheshadetabtotheappropri- ate colour on the Quick Match syringe. I injected the fireable stump shade material into the bridge abut- ments. Once the Quick Match had been injected, I started applying the glaze. The glaze turned the ceramic into a window showing us the internal core value. This makes staining the ceramics an easy process once firing is completed. The process can be repeated should more stain be required (Fig. 7). I personally find that using the Quick Match product not only creates the right stump shade value, but is also great to use whenfiringsmallabutments that will not fit a peg (Fig. 8). The final result is a bridge thatisvirtuallyindistinguish- able from the original. This was all completed in a two- hourvisitandthepatientwas very pleased with the final result. In this particular scenario, I was not worried about the bridge failing because of the size of the connecters. I know that using a feldspathic ceramic is not the number one choice;however,theamountofloadontheanteriors will not be such that the bridge will fail (Fig. 9)._ Chris Leinweber is the owner of Kensington Dental Ceramics located in Calgary.He is a registered dental technologist, a certified dental technician and an ISCD-certified CEREC trainer.He currently provides two-day advanced CEREC courses atVident CEREC University in Brea, California,USA.He lectures internationally and is the creator and host of the innovative CEREC Made Easy DVD training series.All his training material and an updated course schedule are available online at www.cerecmadeeasy.com. CAD/CAM_about the author Fig. 8 Fig. 9 Fig. 7Fig. 6