The replacement of old metal-ceramic crowns for metal-free zirconia crowns
Our female patient, aged 37, reported to our clinic with the following requests:
- Her teeth had made her reserved.
- Aesthetic restoration was all-important for her since she wanted to feel at ease to smile
- She sought to have flawless and uniform teeth.
At the first encounter a panoramic radiograph and photographs were taken of the teeth. The radiograph and thorough examination of the mouth revealed that the upper left premolar had chipped off and needed to undergo a second root canal treatment and to be reinforced with a post and core for the secure retention of a crown. The upper two central incisors and right lateral incisor had also been root canal treated and needed to be reinforced with post and core abutments. After weighing the options with the patient we decided in favour zirconia crowns to be placed on the upper incisors and the chipped-off premolar. Aesthetics can be best restored with a metal-free solution but since the teeth were root canal treated and had post and core abutments our choice fell on zirconia crowns instead of all-ceramic crowns.
Panoramic radiograph of the initial condition
Once the teeth were filed down and prepared a precision impression was taken thereof. Tartar removal and Zoom 2 in-office teeth whitening were performed to be able to match the colour of the all-ceramic crown to the restored colour of natural teeth and achieve a perfect smile. The patient’s every single request and photographs were forwarded to the dental technician.
While the permanent crowns were being fabricated the tooth preparations were covered with provisional crowns using the Scutan procedure in order to protect them and provide an aesthetically acceptable condition for the turnaround time of the zirconia crowns. Several trial fittings follow impression taking while the dental technician is proceeding with the fabrication of the crowns.
During the framework trial fitting, the impressions are checked for trueness, and the frameworks of the tooth restorations are checked for accuracy and a seamless fit of on the master cast. Front teeth zirconia crowns have a white framework and are milled using the CAD/CAM computer-driven technology.
At the preliminary trial fitting the crowns are almost complete with the ceramics already sintered onto the framework with a matte finish. At this trial fitting the patient’s bite (function), the shape and colour of the crowns and the midline and smile line can be checked again (aesthetic trial fitting).
Several days may elapse between the different trial fittings while the dental technicians are working on the tooth restorations in the background.
If no adjustments are required following the preliminary trial fitting, the crowns are given their final glossy finish. With the permanent crowns cemented on our patient recovered his self-esteem and feels at ease to smile again.
Implant-borne tooth restorations require as much, if not more attention, care and follow-up as restorations retained by natural teeth. It is often thought that tooth restorations need no professional tartar removal, but this is a misbelief. There is a close relationship between oral hygiene, the quantity and quality of tartar and the long-term success of the implants. To this end, make sure to abide by the following instructions:
- Reporting for regular annual follow-up, which is also a condition for warranty.
- Professional tartar removal every once or twice a year.
- Use of dental floss (Super Floss) for cleaning bridges and a suitably sized interdental brush at least once in the evening before going to sleep.
- Thorough brushing after each meal, preferably with a soft bristle tooth brush.
Follow-up panoramic radiograph of the zirconia crowns designed for natural teeth