Planning implants crown down--a systematic quality control for proof of concept.
OBJECTIVE
We evaluated an innovative approach for conventional surgical or transmucosal implantation applying backward planning with bone oriented crown down implant positions, followed by immediate restoration.


METHODS
Our workflow combined computer-assisted preoperative planning with the well-known intraoperative handling of surgical templates. To guarantee optimal accuracy, the complete process was bone borne, not soft tissue borne. Furthermore, in this concept, the definite prosthesis was manufactured on a plaster cast and fixed with technical implants inserted into the model using the same drilling template applied for intraoperative guidance of the drill. This bone-based workflow avoids the accumulation of errors throughout all steps of the treatment. In the present study, we have provided a concise quantitative quality control using 4 in vivo implants. This goal was accomplished by image matching of the preoperative plan with the corresponding postoperative computed tomography scan, applying descriptive statistics, the 1-sample t test, and the Student t test.


RESULTS
Statistical evaluation showed that the bone-borne drilling template provides sufficient accuracy for immediate restoration with the definite prosthesis at the end of the operation. Deviation in the apex plane was 0.8 ± 0.42 mm, with 0.33 at the maximum. The angular deviation was 3.18° ± 0.78°.


CONCLUSIONS
Our workflow is a promising approach with respect to handling, accuracy, and intraoperative safety.
University Clinic of Maxillofacial Surgery, Medical University of Vienna, Vienna, Austria. rolf.ewers@meduniwien.ac.at
Rolf
R
Ewers
Rudolf
R
Seemann
Gerald
G
Krennmair
Kurt
K
Schicho
Ayman Omar
AO
Kurdi
Axel
A
Kirsch
Astrid
A
Reichwein
D000044:Dental Abutments; D003758:Dental Implantation, Endosseous / Q000295:instrumentation / Q000379:methods* / Q000592:standards; D015921:Dental Implants / Q000592:standards; D017267:Dental Prosthesis Design / Q000592:standards; D019094:Dental Prosthesis, Implant-Supported; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007430:Intraoperative Care / Q000295:instrumentation; D003765:Models, Dental; D010347:Patient Care Planning / Q000592:standards; D011786:Quality Control; D012984:Software; D014057:Tomography, X-Ray Computed
D015921:Dental Implants