Tooth extraction, bone graft (sinus lift), implant surgery, screw-retained implant fabricated with CAD CAM technology, metal-ceramic crown
Our patient aged 66 reported to our clinic with the following requests:
- His front left root canal treated tooth had chipped off.
- He sought to have an overall assessment of his teeth and existing implants
- He desired to have the required treatments done.
- Should a tooth be extracted, he would like to have it restored with an implant.
- He did not keep aloof from a bone graft if that is the only way to install a dental implant.
First treatment session (3 workdays)
At the first encounter a panoramic radiograph was made, and following the examination of the oral cavity a treatment plan was drawn up which handed over to our patient with a quote included.
In the maxilla, the removal of the upper right first molar (no. 16) and left radix (no. 26 root remnants) was necessary. It was readily apparent from the panoramic radiograph that if an implant was to be installed, following healing a bone graft surgery (sinus lift) was indicated in the upper right quadrant where bone height was inadequate.
At our patient’s request only the left tooth was removed at this treatment session. Since he travels extensively and has to attend appointments his treatment schedule was broken down into several short sessions, so that his off time could be reduced to a minimum.
At our patient’s request no immediate denture was fabricated for the time of healing. The absence of this single rear tooth is inconspicuous and not wearing an immediate denture is more conducive to healing too. And not least of all, this way our patient could also save money.
Panoramic radiograph of the initial condition. The existing 3 implants were not installed at the Suba Dentál Clinic.
Second treatment session (3 workdays)
At the second encounter a CBCT (Cone beam computed tomography) scan was made in order to examine residual bone mass in 3 dimensions prior to the implant surgery. The CT scan revealed that at the site of the molar extracted 3 months earlier on the left hand side bone width and height were appropriate for an implant to be installed. Since the stability of the implant exceeded 30 Ncm the gums could be sealed with a gingiva former following surgery. Simultaneously, the focally infected molar in the upper right quadrant was removed. No immediate denture was fabricated and nor was one made for the other side.
A CT scan picturing the maxilla and the maxillary sinus where bone height and width can be examined in 3 dimensions. The lower 3 images demonstrate a bone height of 13.4 mm which qualifies as ideal bone mass for a dental implant.
Follow-up panoramic radiograph capturing a DIO implant installed at the site of tooth number 26 and the removal of tooth number 16
Third treatment session (5 workdays)
Following 5 months’ postoperative healing we were able to set about the fabrication of the permanent restoration. Our patient opted for the screw-retained implant crown. With screw-retained implant crowns, whenever an issue arises with the implant or the ceramic crown is damaged the screw-retained implant crown can be removed, the implant underneath treated and the same crown can be placed back on following treatment, without a new crown being necessary.
A precision impression was taken of the implant by means of a closed-tray impression coping. The dental technician thus obtains an accurate picture of the position of the implant and the adjacent teeth and can fabricate a crown that perfectly blends in with its environment.
In our patient’s case we decided for the cutting-edge screw-retained metal-ceramic crown. The essence of the so-called CAD CAM procedure is that the abutment and the metal base of the crown do not require a two-piece assembly but are milled from a single “block” by a computer-driven machine. Once ready, the base is given a ceramic sintering much in the same way as its “conventional” counterparts.
The finished crown only needed to be screwed in place with a screw and the site of screw head sealed with a filling.
In order to examine the site of the upper molar removed at the previous treatment session a CBCT (Cone beam computed tomography) scan was recorded allowing for a 3 dimensional examination of residual bone mass prior to the implant surgery. The CT scan revealed that bone height was indeed way too low for an implant to be inserted and a bone graft surgery (a so-called sinus lift) would be necessary. Our patient was not taken unawares by this piece of news and willingly consented to the intervention. Since there was at least 4 mm of residual bone height bone graft and the insertion of the implant were scheduled simultaneously, and meanwhile the dental technician was proceeding with the left hand side crown.
The treatments will be resumed after 6 months’ healing time, that is, when a crown will be fabricated for the upper implant. A dental implant surgery necessitating a bone graft requires 6 months for the implant to osseointegrate before a permanent crown can be fixed on.
Dental implant restorations require the same, if not more, attention, care and follow-up as those retained by natural teeth. Patients are advised to report for a short check-up, tartar removal and bite check twice in the first year. There is a close relationship between the tartar and the long-term success of the implants. It is advisable to frequently check occlusion since if the crown is not a hundred per cent comfortable, the porcelain may chip off due to overload or traumatic occlusion and inflammation around the implants (periimplantitis) may develop.
Follow-up panoramic radiograph with an implant installed at the site of (upper left) tooth number 16. The whitish granular tracings around the implant indicate the bone graft material inserted in the course of the sinus lift
Follow-up panoramic radiograph of the implant and bone graft inserted at the site of tooth number 16 and the screw-retained metal-ceramic implant crown installed at the site of tooth number 26.
The single-unit abutment and base of the crown fabricated with CAD CAM technology
The screw-retained metal-ceramic implant crown installed at the site of tooth number 26 on the master cast
The screw-retained metal-ceramic implant crown with the screw driver with which the crown is screwed in place – as laid out on the master cast
Side view of the screw-retained metal-ceramic implant crown designed for the site of upper left tooth number 6 as laid out on the master cast
The gums perfectly shaped by the gingiva former above the implant.
Bottom view of the screw-retained metal-ceramic implant crown designed for the site of the upper left first molar (as seen in a mirror)
Side view of the screw-retained metal-ceramic implant crown designed for the site of the upper left first molar (as seen in a mirror)
The screw-retained metal-ceramic implant crown designed for the site of the upper left first molar covered with a permanent composite filling (as seen in a mirror) in the mouth.
On top of the screw-retained crowns a small hole can be seen, through which the crown is screwed in place. This hole is covered with an aesthetic filling. Unfortunately a composite filling does not cover perfectly well and the hole sometimes shows through to some extent but only for “those looking to find” an aesthetic fault with the tooth. Ideally this small hole only contrasts in colour and is indiscernible during speech or laughter – especially on an upper rear molar.
Keywords: implant, dental implant, screw-retained implant crown, metal-ceramic crown, CAD CAM procedure, bone graft, sinus lift, bone graft material, tooth extraction