What is the Success Rate for "All on Four" Dental Implants?

I read ALOT. I've also restored ALOT of All-on-4 cases myself. The answer must be based on science!! The doctor that invented the procedure (Dr. Malo) published many papers on longterm followup, with good results. The All-on-4 was originally designed to replace the lower teeth, since lower conventional dentures are very poorly accepted by patients. There is more data on lower All-on-4 treatments...He will have 15 year data on these patients soon. Since there was good results on the lower, they started tracking the upper treatment outcomes, which they only have 5 year followup (soon 10yr). He looked at a couple of different things--- 1. Teeth vs. No teeth? Do success rates differ if the patient has teeth currently that need to be extracted, compared to a patient that needs the All-on-4 with no teeth at all?? Or in other words: Does the patient currently have a few missing teeth (partial edentulism) or are they already missing ALL of their teeth (full edentulism)... Does it matter?2. Upper Arch (Maxilla) vs. Lower arch (Mandible)? Bone is typically more dense in the lower mandible compared to the upper maxilla. Does it matter?Actual Success Rates for "All-on-4" implants:Lower Arch: 5 year followup: 94.8 percent (for people that had the procedure and started with full edentulism; no teeth at all) and 98.1 percent (for partial edentulism)10 year followup: 93.8 percent (started with full edentulism) and 94.8 percent (for partial edentulism)Upper Arch:5 year followup: 93 percent (full edentulism)Generally speaking, longterm success depends on many factors: patient compliance, hygiene, use of night guards, overall systemic health of patient, grinding of teeth (bruxism), general wear and tear from usage of bridges, trauma, smoking, etc.Overall, the procedure has some of the highest success rates for ANY dental procedure. However, there is a trend that the lower treatment is slightly more successful than the upper, nonetheless, BOTH are in the ++90%. The above information is for educational purposes only. You should have a consultation with your Prosthodontist and Oral Surgeon prior to any treatment.

While you may read that the success rate for implants is quite high nowadays (e.g. 99% or even higher), it all depends on a variety of factors. The brand and material of the implants is key, because scientific tests have shown certain materials such as Titanium to be most compatible with human bone and therefore have greater chances of integration. Many top tier companies have patented their own designs of implants which are also recognized for achieving greater torque, etc. The patient's set of circumstances will also affect the chances of implant survival. Will patients comply with post-op instruction during the healing period? Are they smokers? Do they suffer from diabetes or other health conditions that may compromise or slow down integration? Lastly and most importantly, the skill and experience of the implantologist is crucial, as is the approach used in installing the implants. All-on-Four implants tend to have higher chances of success because implants are splinted together with the provisional denture during the healing period. This distributes chewing pressure more evenly, preventing undue strain on any single implant.

Full arch implant treatments have a very high success rate overall, but there are different outcomes depending on how the case is planned out. When a patient presents to our office wanting full arch implant treatment, I do not stop with 4 implants. I place as many implants as the bone will allow.  The reason for this is more implants more foundation. This basic building principle applies to building houses and also dental implants because if there are 8 implants and 1 fails, it is not a big catastrophic deal. If there are  4 implants and 1 fails, the whole structure fails. 

At our facility, our procedure has a success rate of 99.9% for a non-smoker and 98% for a smoker. Titanium is an extremely biocompatible material, meaning the body does not reject it. Titanium is used in other common procedures like hip and knee replacements. It is rare for an implant to fail if done in the right facility. 

Most of the dental implants are made of Grade 4 and 5 Titanium. Titanium is one of the most bio compatible materials used in medicine and dentistry, i have never seen anybody allergic to titanium in my 2 decades of implant experience. As far success rate of All-on-4 implant protocol is concerned, in our practice we have consistently noticed that the it is 99.6%. Most important factors that contributed to this is the experience of the implantology team in planning and execution, supported by accurate vitual planning using the inhouse CBCT Scan facility alongside precision prosthesis post operatively having an inhouse dental lab with highly ecperienced Master Technicians.

since I can see that you already have got answers for the success rate of the all on four prosthesis it varies between 95%- 99 percent. Yet there are so many factors which can govern success of all on four in your case. 
An important advice is you should go for All on four only if it is indicated or adviced by your implantologist or prosthodontist . That means if you have good quality of bone in the back region where implants are possible then it is better to have 6-7 I implants for the longevity and stability of the prosthesis. 
Regarding your second question to develop any negative reaction due to implants,  fortunately titanium is the most biocompatible and allergy free material being used in dentistry since decades. So don't worry it's absolutely safe. Now whether your body will be able to take up the implants placed is based on various factors like your age , healing capacity, quality and quantity of  jaw bone, any medical illnesses, presence of decayed tooth. 

All on 4 style dental implant treatment is one of the most successful dental implant procedures available.  This is not simply conjecture, it is published fact.  Studies evaluating traditional dental implant treatment show success rates that range from approximately 93-98%.  Studies evaluating All-On-4 style dental implant treatment typically show success rates in the range of 98-99%.  Why the higher success rate for All-On-4 style implant treatment?  First of all, this treatment allows all of the implants to be splinted (attached) together allowing them to work as a team rather than individual implants.  Second, the back implants are angled in relation to the front implants which creates a "truss" effect very similar to the trusses that are used in traditional bridge building (bridges that cars and trains drive on!).  Same design concept.  

The question should be more like: why do all on 4? All on 4 implant design has been around for many years but not well studied. It was created for low cost alternative to proper multiple implant design and prosthesis. It's really an "under-treatment" for the purpose of keeping costs lower then they should be. The problem with this alternative is that if one implant fails, the entire single unit prosthesis that sits on all four implants will fail too and will need to be remade at full cost. Think twice about doing this treatment modality. In my extensive 20 PLUS years experience with dental implants, all short cut modalities (such as all on 4) fail and in most cases cost more then it would to do it right the first time. My 2 cents.....

There are
actually 2 answers. One is implant survival
rate which is 93-98%. Since there are a minimum of 4 implants placed, this may
not mean a failure of the implant supported bridge if one of the implants fail. Secondly and more importantly is the prosthesis (implant bridge) survival rate. I prefer to place more than 4 implants if space permits. This means that if an implant fails, which is rare, the prosthesis is still
a success. According to Dr. P. Malo, the
originator of the All on 4 concept, the bridge survival rate in the lower jaw
was 99.2% after 10 year follow up. In
the upper jaw, after 5 year follow up, the bridge survival rate was 100%.

All on 4 technique was created by Dr. Paulo Malo and many research papers have shown an excellent success rate.  The success rate of the prosthesis is close to 100%.  The average implant survival rate is about 95%.  Since the All on 4 uses four or more implants per arch, a loss of one implant does not equate to failure of the restoration.  If an implant fails for various reasons, the implant can be replaced or repositioned to acheive a better final prosthesis.The titanium used in dental implants are biocompatible.  Titanium is prefered in dental implants due to is ability to osseointergrate and its corosion resistance.