You might have seen ads on TV advertising “teeth in one day”, “get teeth in one appointment” or “get permanent teeth”.
The majority of my patients who have done research on it ask me what is “all-on-four”. This concept came from placing 4 implants in one arch. The two back implants are angled to avoid bone graft in the sinus, make the treatment more affordable or simply the patient does not have a lot of bone.
You might be wondering, does it have to be long angled implants always? Do straight implants work the same? What is best?
Is there are any alternatives to “all-on-four?
There are actually a few alternatives a clinician, I personally prefer to have straight implants, whenever possible and more than 4 implants (See impression case with temporary abutments below).
+ Stone model reproduced from making an impression of the implant in patient’s mouth ready to start designing the final teeth
+ Frontal view of the same case mode before the fabrication of final Prosthesis, “permanent teeth”
Factors that I worried about this patient when I planned the case, placed the implants and design final prostheses :
- Avoiding a cantilever on the last few teeth can prevent fracture of the prosthesis
- Six implants provide a better prognosis long term. In the case one implant was to fail, the prosthesis continues to work well. In the case of 4 implants, the case is over.
- Whenever the patient has bone available, it is easier to place straight implants and easier to restore, in my hands.
- This patient is a clencher and bruxer
- For this patient, I went one step further. I planed the implants straight to do an implant level prosthesis and avoid using multi-unit abutments. This has worked very well for me and the patient is doing very well.
What I like the most doing it this way is that the implant screw is much longer, thicker and stronger compared to the tiny screw for the multiunit abutment.
+ View of the lower jaw when the bone was leveled, 5 straight implants placed and the patient is ready to close gums and allow for healing.
In my opinion, more than 4 implants (6 on the maxilla and 5-6 in the mandible) is a safeguard for the potential longer survival of the prosthesis and follow the scientific guidelines of recommended implants.