All-on-4

All-on-4 is a very suitable method for implant treatment of patients with severely degraded teeth that cannot be therapeutically restored, as well as in cases of loss of all teeth due to aggressive forms of generalized periodontitis. 

Indications for All-on-4 implant placement

In practice the use of All-on-4 is possible in almost all edentulous patients. The All-on-4 technique is applicable even in cases when the classic implant technique is extremely difficult to perform, for example due to high bone resorption (loss) in the chewing area, superficial location of the mandibular nerve or a very thin bone plate covering the sinus in the upper jaw. All-on-4 helps to avoid additional difficult interventions such as sinus lift, bone augmentation, etc. The only condition for the application of All-on-4 is to have sufficient residual bone in the frontal part up to the premolar area. 

The strength of the construction and the good prognosis of the treatment using the All-on-4 method are determined by the correct technique for implant positioning. In particular, two implants perpendicular to the bone and parallel to each other are placed in the frontal area, while another two implants are placed in the lateral area at an angle of 30 - 45°. The tilt increases significantly the contact surface between the implant and the bone ensuring excellent primary stability of the construction, maximum retention force and reliable service through the years. This allows for immediate implant loading with a construction, straight after implant insertion.

Multi-unit abutments are placed on the inserted implants. During the same visit or within three days at the most, a reduced volume prosthesis is installed.

After a 4- to 6-month period of osteointegration of the implants the All-on-4 treatment can be completed with loading of an aesthetic metal-ceramic or zirconia construction.

Advantages of the All-on-4 method: Affordable price – only four implants are inserted in the jaw. With the All-on-4 method the patient can select from a wide range of prosthetic solutions. The definitive construction can be:
a reduced plate prosthesis;
a plastic PMMA CAD-CAM construction;
a metal-ceramic or zirconia construction for incomparable and irreplaceable aesthetic look, durability and comfort.  

Advantages of the All-on-4 method: Fast recovery process and minimal trauma – the insertion of the four implants takes no longer than an hour (see surgical guides) and is performed under local anesthesia or sedation. The pre-prepared construction can be corrected immediately and the patient may walk out of the office with new teeth on the same day. Advantages of the All-on-4 method: Equal distribution of the load along the jaw bone;

Advantages of the All-on-4 method: Long service life – 10 years for the lower jaw and 5 years for the upper jaw;

Advantages of the All-on-4 method: Possibility for replacement of the prosthetic construction;

Advantages of the All-on-4 method: In most cases All-on-4 does not require bone grafting;

Advantages of the All-on-4 method: No rehabilitation period – in the treatment using the All-on-4 method you can eat properly, smile and have conversations immediately after the intervention;

Advantages of the All-on-4 method: The risk of consecutive bone resorption/atrophy is significantly reduced;

Advantages of the All-on-4 method: Complex restoration of functionality and aesthetics.

The limitations of the All-on-4 method with respect to the implant insertion phase of the treatment are the same: uncontrolled diabetes, cardiovascular diseases, disrupted blood clotting.

Disadvantages of the All-on-4 method

In spite of all listed advantages of the All-on-4 method, the reduced number of implants is not optimal. This can easily be explained. One implant has, more or less, the shape and size of a tooth root. In the upper jaw the chewing load is distributed over a minimum of 24 roots versus 18 roots in the lower jaw. Regardless of the implant system applied, its qualities or the precision of implant insertion, we CANNOT reproduce adequately the potential set by nature with only 4 implants. Furthermore, due to the lower bone density, dental practitioners consider the All-on-4 method risky and recommend the All-on-6 technique.