Zirconia (zirconium dioxide) crowns are made of solid monolithic zirconia ceramic material. Although discovered in 1789 by the German chemist Martin Heinrich Klaproth, zirconia has been used as a biomaterial since the late 1960s. Its use as a dental restorative material became popular in the early 2000s with the advent of CAD-CAM technology. In the later part of the decade they became available as preformed crowns for primary teeth.5
Zirconia Crown Technique (technique description and illustrations courtesy of EZ Pedo Crowns)
Reduce the lingual surface by removing .75-1.25mm of tooth structure from the lingual surface, extending from 1-2mm subgingivally to the middle of the incisal edge of the prep following the natural contours of the existing clinical crown. The facial and lingual preps should meet in a thin incisal edge. Check the occlusion to insure there is adequate clearance from opposing dentition.
Preparation for Cementation
Rinse the preparation and remove all blood and residue from the tooth. If bleeding continues, squeeze the preparation with a moist 2x2 gauze or carefully apply Superoxol to the tissue using a micro brush. Using peroxide or alcohol, thoroughly clean the internal surface of the crown so that all blood residue is removed.
Cementation is the most important step to creating a beautiful smile. Tooth orientation and emergence profile are key. Centrals should always be cemented together first and then the laterals. Apply consistent, firm finger pressure during cementation using glass ionomer cement. The crown should remain undisturbed until the cement has completely hardened. Wiping excess cement from the facial embrasure will allow a clearer facial view and insure a better final alignment, dramatically improving the final esthetic result. Tooth labeling can be scratched off with a spoon or polished off with coarse prophy paste.
With all full coverage restorations parents must be advised to institute appropriate preventive health practices (elimination of sugar containing drinks, regular tooth brushing and topical fluoride application) to maximize gingival health and minimize the recurrence of caries under the restorations.