Guided implantology: the procedure planned in advance

What guided implantology means

In the conventional approach the dentist decides the direction and depth of the implant during the procedure itself, from what he sees and feels. In a guided approach that decision is made in advance — on a computer, on a model built from your own scans.

There are usually two things behind it at once: a three-dimensional X-ray that shows the shape and thickness of the bone as well as the course of the nerves and the sinuses, and a scan of the teeth or of their plaster model, which captures the gums and the neighbouring teeth exactly. An X-ray on its own does not say where a new tooth will look right; a scan on its own does not say where there is enough bone beneath it. Only put together do they give a model in which both can be planned at once.

How the plan and the surgical template are made

In the combined model the implant is placed where it needs to be for the future crown, and then it is checked whether the bone really is there and whether it comes too close to the nerve or to the sinus. If it does not fit, the position is changed on the screen — not in the mouth.

The procedure usually has four steps:

• a three-dimensional X-ray of the jaw and a scan of the teeth or of their model
• combining the two into a single model and planning the position of every implant
• making the surgical template that transfers this plan into the mouth
• the procedure itself, in which the template guides the drilling in the planned direction and to the planned depth

The template is in effect a form seated on the teeth, the gum or the bone, with guide holes exactly where the plan put them. It does not do the procedure for the dentist — it holds the direction that was decided beforehand.

What you get out of it

The main difference is that the position of the implant is not estimated during the procedure but copies a decision made calmly, one that could be rewritten as many times as it needed to be.

A few practical things follow from that:

• the implant goes where the plan put it, even in places where there is little bone or the nerve is close
• if conditions allow, the work can be done through a smaller access or without cutting the gum, only through the opening in the template
• the time spent in the chair tends to be shorter, because what has already been decided is not decided again during the procedure
• the crown or bridge can be prepared in advance, once the position of the implant is known before it is even placed

What a guided procedure does not solve

Planning on a computer does not create bone that is not in the jaw. If there is too little of it in the intended place, the plan will show that more precisely than anything else — but the answer is still to add bone or lift the floor of the sinus, or to place the implant differently. Precise planning here prevents an unpleasant surprise during the procedure rather than replacing missing tissue.

Nor is it an approach that suits everyone. The template together with the instruments takes up a height in the mouth that has to be opened up — with the back teeth, and where mouth opening is limited, that is often the reason for going the conventional way. And access without cutting the gum is not always right: where there is little firm gum around the implant, it is better to lift it and see it than not to see it at all.

How accurate it really is

A guided procedure is not flawless and should not be presented as such. Reviews of the literature comparing the planned position of an implant with the actual one after the procedure repeatedly measure deviations in the order of a millimetre and a few degrees. That is considerably less than freehand estimation, and at the same time it is not zero.

The template is only as good as the scan and the plan behind it. An inaccurate scan, a template that does not sit firmly during drilling, or a plan made in a hurry will carry their error into the mouth just as reliably as a correct decision. It is a tool that helps an experienced dentist do more precisely what he has decided to do — it does not replace his judgement or his experience.

What it costs

The way into the whole procedure is an examination. The implantology consultation is free with us; of the X-rays, it is the 3D image at 40 € that matters for three-dimensional planning, while the panoramic OPG image at 15 € is a flat overview and is not enough on its own to plan a position in space.

The implant itself is priced by system — MegaGen 350 €, Straumann 650 € — and the abutment that joins it to the crown costs 150 €. If the examination shows there is not enough bone, a large augmentation during a longer procedure costs 480 € and sinus lifting 900 €.

Neither the planning nor a surgical template has its own item in our price list, so what exactly your case will need and what it will cost is something we go through at the consultation.

Whether a guided procedure is needed in your case, and whether it is possible at all, will only be shown by an examination in person with an X-ray.