Restoration of edentulisms and discoloration due to tetracycline and elimination of gaps between teeth (diastemata) with zirconia crowns
Male patient in his forties reported to our clinic with the following complaints:
- He was greatly disturbed by the deteriorated aesthetics of his teeth.
- He did not dare to smile in company due to the greyish-yellowish colour of his teeth.
- He wanted to have the gaps between his teeth (diastema) eliminated.
- He a sought to restore his self-esteem by repairing the aesthetics of his teeth.
- He desired to feel to at ease to smile.
- Since he is young, he would be in favour of metal-free crowns for their aesthetic appeal.
Aesthetic rehabilitation with zirconia crowns (10 workdays)
At the first consultation and clinical examination it was determined that all teeth could be preserved. Having received information on the treatment, the patient decided in favour of a metal-free restoration, i. e. zirconia crowns. When multiple teeth need to be filed down, one day is devoted to teeth in the lower arch and another one to teeth in the upper arch and precision impressions are taken thereof. Once the teeth are prepared, the precision impressions along with the patient’s aesthetic requests are forwarded to the dental laboratory. Until the completion of the permanent crowns, the tooth preparations are fitted with provisional (plastic) crowns (fabricated with the Scutan method) to protect them and ensure acceptable appearance. The provisional crowns are fabricated at the chairside immediately after the treatment, so the patient does not have to leave with filed-down tooth stumps. These plastic provisional crowns can be removed during the treatments and placed back on following treatment.
Following impression taking a gnathological treatment (viz. an instrument-aided bite registration) was performed with an (Artex facebow) in order to see the exact position of the jawbones and the tooth preparations in the articulator and determine the correct occlusal position of the temporomandibular joints for the patient’s new crowns.
Trial fittings form a crucial part of the treatment for the timely recognition and easy rectification of any issues that may arise. The first trial fitting is that of the framework, during which the impressions and the framework are verified for accuracy and all tooth restorations must seamlessly fit the master cast. The lengths of the framework and the tooth are checked along with the middle position of the central incisors and the rearward curve of the teeth. This serves as the basis for aesthetics, since, for instance, if the framework proves too long, the tooth also will be too long, which is unappealing. If all is found in order at the trial fitting of the framework, the trial fitting of the matte teeth may ensue. At the trial fitting of the matte teeth the teeth are almost ready having received their ceramic coating (with ceramics already sintered on). This trial fitting allows a closer verification of occlusion (function) and the shape, colour and centre and smile lines (trial fitting for aesthetics). Trial fitting of the matte teeth is only followed by handover, during which the crowns are permanently glued in place. At handover the patient was shown the ins and outs of cleaning and accessories to be able to carry out cleaning at home.
Our patient left satisfied with the results. He pledged to return once a year for follow up and tartar removal (scaling).
What to know about zirconium crowns?
Commonly referred to as zircon crowns, this crown type actually has a zirconium dioxide framework, hence the designation. Zirconium itself is an element found in the periodic table among metals, and as such it displays great mechanical strength. However, it cannot be used for medical purposes until it comes into chemical reaction with oxygen, which gives rise to zirconium-dioxide (zirconium oxide, zirconia), a highly resistant material, metal-free by now and with a high melting point.
- Applicable with discoloured teeth reinforced with metal post and core abutments.
- Applicable with dark and discoloured root canal treated teeth as no greyish hue will show through.
- The framework of the crowns is created using CAD/CAM technology, which means that a high precision computer-driven machine mills them out with an error margin of less than a few microns.
- Can be used for stand-alone crowns or bridges, as well as in the molar region.
- Can be applied both for the abutment of natural teeth and implants.