Guided Implant Surgery

Guided implant surgery is a method in which the implant is planned on a computer before the operation and placed according to that plan during surgery. It is not a different type of implant; the implant used is the same. What changes is how the implant's position is decided and how it is placed in the bone.

In the conventional method, the surgeon studies the CT scan, makes a plan and places the implant freehand based on that information. In the guided method, the CT scan and an intraoral scan are combined on a computer; the length, diameter, angle and depth of the implant are decided on screen, with the surrounding nerve, sinus and neighbouring tooth roots in view. A custom guide that fits the mouth is then produced from this plan. During surgery, the sleeves in the guide help the drills and the implant follow the planned direction.

There are two approaches:

• Static guide: A plate made on a 3D printer according to the plan, which rests on the teeth, gum or bone. It stays in the mouth during the operation.
• Dynamic navigation: No plate is used in the mouth. Special cameras track the position of the drill in real time, and the surgeon follows its position against the planned path on a screen.

The guided method is not necessary for every implant, but in some situations transferring the plan directly to surgery is especially useful:

• When several implants are to be placed or implants are planned for a whole jaw (such as All-on-4 and All-on-6)
• When the implant site is close to a nerve, the sinus or neighbouring tooth roots
• In areas where appearance matters, such as front teeth, where the angle and depth of the implant directly affect how the tooth looks
• When the procedure is to be done without an incision or with a small one and the bone is suitable for this
• When a temporary tooth is prepared in advance to be fitted shortly after surgery
• When bone volume is limited and the available bone needs to be used as well as possible

In some cases that need additional procedures such as bone grafting or a sinus lift, the area has to be opened and seen directly. In these cases the guide can help with planning, but the procedure may not be possible without an incision.

1. 3D CT scan. The height, width and density of the bone and the position of structures such as nerves and the sinus are imaged.
2. Intraoral scan. The teeth and gums are scanned with an optical scanner or an impression is taken. This record is needed for the guide to fit the mouth precisely.
3. Digital planning. The CT scan and the intraoral scan are superimposed on the computer. First the ideal position of the future tooth is decided, then the implant is placed in the bone so that it supports that tooth best. In other words, the plan is made backwards from the tooth.
4. Confirming the plan. The position, angle and length of the implants are checked one last time; where needed, the temporary tooth is designed on the same plan.
5. Producing the guide. If a static guide is used, it is made on a 3D printer according to the plan and its fit in the mouth is checked.

The area is numbed with local anaesthesia; you feel no pain during the procedure. The guide is placed in the mouth and its fit is checked. If the bone is suitable, only a small opening the width of the implant is made in the gum; if needed, the gum is lifted with a small incision. The drills pass through the sleeves in the guide to prepare the planned site in the bone, and the implant is placed.

When no incision is made or it is kept small, there are usually fewer stitches and swelling and tenderness after surgery may be milder. In suitable cases, a temporary tooth prepared in advance can be fitted the same day or shortly afterwards. The healing period and making the permanent tooth are the same as with conventional implant treatment (see Dental Implants).

• The plan is carried into surgery. The implant's position is decided in advance, with the surrounding structures in view; there is less guesswork during surgery.
• Deviation is generally lower than with freehand placement. Scientific studies report that deviation from the planned position is generally lower with guided placement than without a guide.
• Working without an incision or with a small one may be possible. In suitable cases this can mean fewer stitches and a milder healing period.
• Surgery time may be shorter. Because most decisions are made during planning, the procedure proceeds more predictably, especially with multiple implants.
• The tooth and the implant are designed together. Because the implant is planned in the position that best supports the future tooth, a result that is better for appearance and chewing is aimed for.

Guided surgery is a powerful aid, but it is not a magic solution. There are limitations you should know about:

• Deviation is not zero. A guide can also deviate by fractions of a millimetre. For this reason, a safety margin is left from structures such as nerves and the sinus during planning.
• Enough mouth opening is needed. With a static guide, the drills pass over the guide, so enough mouth opening is needed, especially for back teeth. For patients with limited mouth opening, dynamic navigation or the conventional method may be more suitable.
• It is only as good as the plan. An error in the CT scan or intraoral scan is carried into the guide; so the accuracy of the records and the fit of the guide in the mouth are checked before surgery.
• It is not suitable for every case. Areas that need additional bone procedures or where the bone is very thin may need to be opened and seen directly.
• It requires extra preparation and cost. Scanning, digital planning and guide production add steps before surgery.

The guided method does not remove the general risks of implant treatment; it aims to reduce them through good planning:

• Mild swelling, tenderness and bruising in the first days
• Infection during healing
• The implant not bonding with the bone; in that case it is removed and can be re-planned once the area has healed
• The guide not seating fully or breaking during surgery; in that case the procedure can continue with the conventional method
• Rarely, changes in sensation near a nerve or sinus-related problems in the upper jaw
• Over the years, gum inflammation and bone loss around the implant (peri-implantitis)

• First 48 hours. When the procedure is done without an incision or with a small one, discomfort is usually mild. Cold compresses and the recommended painkiller are usually enough; avoid hot drinks and smoking.
• First week. Choose soft, lukewarm foods and do not chew on the treated side. Any stitches are removed on day 7–10.
• Healing period. Usually a few months, depending on bone quality. If you have a temporary tooth, avoid putting hard foods on it, and attend your check-ups.
• After the permanent tooth. Daily brushing, floss or interdental brushes, and regular check-ups with professional cleaning.