Toothless jaw restoration

If there is too little bone in the posterior region of the mandible to anchor further implants and the patient wants a fixed screw-retained solution, it is possible with drilling templates (navigated implantation) to place the terminal implant obliquely over the exit point of the mandibular nerve.

The aim is to move the support of the prosthesis as far back as possible so that fewer leverage forces act on the firmly screw-retained prosthesis.

In the upper jaw, 4 implants are only possible if the upper jaw bone has sufficient strength; it may then be possible to dispense with bone augmentation in the maxillary sinus (sinus lift).

If there is too little bone available in the maxillary sinus area, the terminal implant is placed at an angle using a drilling template (navigated implant placement) to achieve sufficient support in the posterior area of the prosthesis. In this way, bone augmentation in the maxillary sinus (sinus lift) may not be necessary.

The prerequisite is the preparation of a DVT X-ray to show the bone availability in 3 dimensions. A drilling template can be fabricated on the basis of this imaging procedure.

Advantage of All on 4 and All on 6 concept:

• less surgical effort
  
• cost reduction, because complex bone augmentation can be dispensed with
  
• immediate temporary restoration is possible
  
• shorter operation times
  

If there is sufficient bone available in the posterior region of the mandible, this should be used in any case to achieve optimum force distribution and force transmission into the jawbone.

A fixed screw-retained restoration or a removable restoration with a bar can then be used.

Navigated implant placement and fabrication of a surgical guide allow faster and gentler implant placement. The prerequisite is the preparation of a DVT X-ray for 3-dimensional imaging of the bone.

For the fixed screw-retained prosthesis in the maxilla, at least 6, preferably 8 implants have proven successful. Bone augmentation in the maxillary sinus on both sides (sinus lift) is often necessary because the maxillary bone recedes very quickly after extraction.

With a fixed prosthesis in the upper jaw, the patient is spared a palatal plate that impairs taste, the prosthesis cannot come loose and the chewing force corresponds to the natural teeth.

Modern imaging techniques have entered implantology in recent years and allow preoperative planning that enables very safe and predictive implant placement.

The 3-dimensional representation of the bone enables backward planning. This means that first the tooth is virtually placed in the ideal position, then the implant is virtually planned underneath in the correct position. In this way it can be determined whether there is sufficiently high and sufficiently wide bone at this position. If there is a slight deviation, a change in the implant position, implant diameter or implant length is sufficient for a suitable implant placement. This is then incorporated into a drilling template and surgical protocol.

If too much bone is missing at this site, virtual bone grafting can be used to determine the missing bone. This virtual bone part is then milled from a foreign bone by a milling machine using the CAD-CAM process (printed via 3D printer in the near future).

Through a surgical procedure, this manufactured bone part is screwed under the oral mucosa where it is needed. The healing time is 4 - 6 months. Then the implant can be placed in the ideal position.

By making drill templates that allow guided implantation, it is possible to implant very gently, possibly even without opening the oral mucosa, which ensures faster surgery, less swelling and less postoperative discomfort.

Planning also makes it possible to fabricate a temporary denture before implantation, so that the patient can be fitted with it immediately after the operation.

Advantages of navigated implant placement and backward planning:

• predictable results
  
• short operation times
  
• less swelling
  
• less postoperative discomfort
  
• immediate provisionalization on the same day
  

There is always enough bone to place 4 implants in the anterior region of the mandible, between the exit openings of the mandibular nerves that provide sensation to the lower lip. A bar can be screwed onto these 4 implants, which remains in the mouth. The prosthesis snaps onto this bar with retention elements and gets an excellent hold. The implants transfer the chewing force directly into the bone, as with natural teeth, so that the chewing performance corresponds to a toothed situation.

If the bone in the upper jaw is sufficiently strong, 4 implants may be sufficient there as well.

The advantage of this treatment method is that the prosthetic restoration can be started immediately after implant placement. It takes about 4 weeks until the final prosthesis is fabricated. If the patient wishes, an immediate temporary denture can be prepared, which is screwed to the implants.

If there is sufficient distance to the mandibular nerve in the posterior region of the lower jaw or sufficient distance to the maxillary sinus in the upper jaw, 6 implants can also be placed for better force distribution and greater chewing comfort.

A bar can be screwed onto these 6 implants, which remains in the mouth. The denture snaps onto this bar with retention elements and gets an excellent hold. The implants transfer the chewing force directly into the bone, as with natural teeth, so that the chewing performance corresponds to a toothed situation.

The advantage of this treatment method is that the prosthetic restoration can be started immediately after the implantation. It takes about 4 weeks until the final prosthesis is fabricated. If the patient wishes, an immediate temporary denture can be fabricated, which is screwed to the implants.

Modern imaging techniques have entered implantology in recent years and allow preoperative planning that enables very safe and predictive implant placement.

The 3-dimensional imaging of the bone enables backward planning. This means that first the tooth is virtually placed in the ideal position, then the implant is virtually planned underneath in the correct position. In this way it can be determined whether there is sufficiently high and sufficiently wide bone at this position. If there is a slight deviation, a change in the implant position, implant diameter or implant length is sufficient for a suitable implant placement; this is then incorporated into a drilling template and an operation protocol.

If too much bone is missing at this site, virtual bone grafting can be used to determine the missing bone. This virtual bone part is then milled from a foreign bone by a milling machine using the CAD-CAM process (in the near future printed via 3D printer).

Through a surgical procedure, this manufactured bone part is screwed under the oral mucosa where it is needed, it heals there for 4 - 6 months. Then the implant can be placed in the ideal position.

By making drilling templates that allow guided implantation, it is possible to implant very gently, possibly even without opening the oral mucosa, which ensures faster surgery, less swelling and less postoperative discomfort.

Planning also makes it possible to fabricate a temporary denture before implantation, so that the patient can be fitted with it immediately after the operation.

Advantages of navigated implant placement and backward planning:

• predictable results
  
• short operation times
  
• less swelling
  
• less postoperative discomfort
  
• immediate provisionalization on the same day