This step-by-step technique shows how to use Komet's Expert Kit 4573ST for all-ceramic anterior crowns.
All-ceramic restorations have long been recognized for their outstanding clinical qualities.
The esthetically desirable results attained with these metal-free, all-ceramic restorations have prompted more and more patients to successfully request them. To achieve a successful all-ceramic restoration, however, all necessary clinical parameters must be considered during the preparation stages (“think ceramic”).
Premature loss of ceramic restoration often is a result of insufficient cavity depth or lack of attention to proper layer thickness. The following recommendations enable the dentist to safely prepare for an all-ceramic anterior crown.
Continue to the next page to see the step-by-step technique
Use the thin instrument (6856.FG.012) to obtain the interdental separation.
Use instrument 6837KR.FG.012 to prepare a 1 mm sized uniform shoulder approximately 0.5 –1 mm above the future preparation limit.
The occlusal view clearly shows the 1 mm circumferential shoulder following the root contour.
Using instrument 6837KR.FG.012 (see step 2), reduce the labial surface of the sagittal curve of the crown by 1 mm.
Reduce the incisal aspect with instrument 6836KR.FG.014, a short cylinder with rounded edges and a green ring. When the instrument is completely introduced, a minimal substance removal of 1.4 mm can be easily accomplished. An occlusal substance removal of up to 2 mm is possible.
With the egg-shaped instrument (6379.FG.023), reduce the palatal aspect by at least 1 mm. To protect the gingiva, placement of retraction cord is recommended following the initial preparation.
For final shaping of the preparation limit to achieve a chamfer with a radius of 0.8 mm, use the larger instrument (6856.FG.021) to simplify access to oral and vestibular areas. When using this instrument, make certain to avoid damage to adjacent teeth.
If adjacent teeth require no preparation, create the chamfer in the interdental areas with the thinner instrument (6856.FG.018) first.
Define the final preparation limit with finishing instruments of matching shape, i.e., 8856. FG.018 and 8856.FG.021.
With the egg-shaped, fine-grit instrument (8379.FG.023 finish the palatal surfaces.
Using a silicone index, ascertain that sufficient substance has been removed.
To complete the preparation for an all-ceramic restoration, round off all sharp edges and corners. Komet flexible polishing discs are particularly suitable for this purpose.