A new method for restoration of the masticatory apparatus in cases of partial or complete edentulism

Nowadays the restoration of partial or complete edentulism is achieved through intraosseous implants combined with fixed or semi-fixed prosthetic structure. However, there are too many cases of insuficient bone due to sinus cavities in the maxilla or extreme atrophy and specifics of the canal in the mandibula. In such cases treatment plans involving intraosseous implants are inapplicable or or only possible after bone grafting which could be a very expensive, time-consuming and unreliable surgical intervention. Moreover, in cases of severe atrophy bone grafting would be hardly possible and with high risk of failure.
An alternative solution is the use of partial or complete plate prosthesis which many patients reject as an option in spite of the active advertising of prosthetic glues, e.g. Corega. Another alternative could be subperiosteal implants. They have been known in Bulgaria and around the world for quite a long time though rejected by patients for a number of reasons. First, dental practitioners not well familiar with this method have long presented it to patients as old and unreliable. Second, the two surgical interventions – one for taking the bone print and one for placing the implant – are considered a setback. The latest world-wide research shows similarity in the outcome of intraosseous and subperiosteal implants. The same conclusions are discussed at recent implantology congresses. In cases of severe bone atrophy when bone grafting and intraosseous implants as well as conventional plate prosthesis are not applicable, subperiosteal implants are the only possible treatment solution. The new aspect in subperiosteal implantology is the introduction of CAD/CAM technologies. The development of computer assisted technologies made it possible to reduce one of the surgical interventions, i. e. the intervention for taking the bone print before designing the implant. This is now done by designing a model of the jaw using tomography data and specialisied software for a computer operated equipment. It could be considered a revolutionary development in the area also because the model is designed with better precision as compared with the bone imprint method thus leading to more precise implant and better success rates of the treatment. Last but not least, under the same conditions, subperiosteal implant restoration would be more cost-effective than using intraosseous implants.




Fig. 1 – The x-ray shows a case of severely atrophic mandibula which does not allow for any type of bone grafting to facilitate intraosseous implants. Restoration with conventional plate prosthesis is also impossible because of the practical lack of gingiva to hold the prosthesis.

Fig. 2 – Top left picture shows the same case. Top right picture shows the first surgical intervation for taking the bone print. The bottom pictures show the print.

Fig. 3 – The top two pictures show the laboratory stage of the production of the subperiosteal implant. The bottom two pictures show the implant with its round joint heads.

Fig. 4 – The top pictures show the implant with the attached prosthetic construction over the laboratory model. The bottom pictures show the second surgical intervention for the implant placement.

Fig. 5 – Top left picture shows a stage of the second surgical intervention. Top right picture shows the implant after the healing of the surgical incision. The bottom picture shows the complete restoration with prosthetic structure.

Fig. 6 – Picture on the left shows the prosthesis. Picture on the right shows an x-ray of the implant.

Fugures 1 to 6 present in detail the classic two-stage method of subperiosteal implantology.


Fig. 7 – A plastic model of the mandibular bone designed through CAD/CAM technology.
Fig. 8 – Prosthesis and implant positioned over the model.

Figures 7 and 8 present the new approach of subperiosteal implantology where the first surgical intervention is avoided. For more information contact pfhristov@yahoo.com