Subperiosteal implants

New is well forgotten old,

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What are subperiosteal implant (SPI) ?

Definition Subperiosteal dental implant is a framework like custom made structure with abutments for support and fixation of dental restorations. SPI's are made from biocompatible materials, mostly CrCo and Ti alloys. Masticatory force is transered to and distributed over large area of bone surface, rather than bulk of the bone, as compared to root form implants.Below you see some historical and current designs. (1,2 mandubular, 3 - maxillar)

1

2

3

Subperiosteal implants

IndicationsIn patients who want to have complete dental arch for proper mastication - usually 14 teeth per arch (or minimum 12 teeth per arch). Extensive bone resorption in mandible or maxilla in patient to whom bone augmentation is contraindicated or patient is not willing to undertake it. Reasons:1. Age or disease related decrease in regenerative capacity of tissues2. Sinus pathology3. Fears, because of multiple surgeries4. Financial and time constraints

Why do wee need them in 2015 ?

Subperiosteal implants

Contraindications

1. Progressive bone resorption because of calcium methabolism disorder.2. Poor quality cortical layer (eg.unhealed extraction sockets) at site of implantation3. Recent (within12 months) irradiation of the head

Manufacturing subperiosteal implants

Making involves three possible ways:1. Classic way as follows: 1st surgery, take bone impression->make refractory model-> model->lost wax casting in CrCo or Ti-> finishing->2nd surgery. It iss the most precise method today, but requires 2 surgeries.2. Hybrid method involves CT data based making of 3D model of the jaw; then model duplication into plaster and refractory model; modeling and lost wax casting in the biocompatible alloy. Finish and perform1 surgery.

3. Pure digital virtual modeling on CT data and direct SLS manufacturing in metal (still experimental), finishing and 1 stage surgery.

Subperiosteal implants

Things, as I do them

Subperiosteal implants Case 1 - maxilla,
initial situation

Subperiosteal implants Case 1 - maxilla,
manufacturing according impression from the bone

gypsum (hard rock) control model

Subperiosteal implants - Case 1
final result

Subperiosteal implants - Case 2 mandible,
initial situation

Extraction has beendone about 14 monthsbefore implantation.

Subperiosteal implants - Case 2 mandible,
hybrid manufacturing

Implant was made using jaw model generated from CT data and manufactured in plastic.Model was duplicated in plaster and refractory model.Implant design was dictated by small space and lack of anatomical retention features.

Plaster model

Subperiosteal implants - Case 2 mandible,
implant placement sugery

Mandible mucoperiosteal flap was risen and impland fixed with titanium screws.

Subperiosteal implants - Case 2 mandible,
results

In this case, intraoral x-ray was taken to check fit of the implant

Subperiosteal implants - that's it for this time

Truly yours - me