All-on-6 dental implants provide a full set of fixed teeth supported by six implants, offering enhanced strength, stability, and long-term durability compared to fewer implant systems like all-on-4. Though all-on-4 works well for many cases, there is an issue with cantilever forces in long-term studies, which might cause some prosthetic failures after 10 years or so. The all-on-6 basically was introduced to completely remove these cantilever forces, and so it's very much like all on 4, but having 2 more implants on each side, like a distal post to remove the cantilever effect.

So, for a good maxilla, all the 6 implants are placed in the premaxilla region and fixed teeth are screw-attached to the implant, but if the maxilla is deficient, where only four can be placed in the premaxilla...then 2 implants are placed into the pterygoid bone of each side, and so it's called all on 6 with pterygoids.

At your dentist, Dr. E. Surendranath, always go for a bicortical engagement, i.e., he engages both the cortices of a jaw bone with implants, and so the stability is way more than the generally followed unicortical engagement technique. and also due to this bi-cortical engagement, the immediate loading is also possible due to the additional stability produced by the bi-cortical engagement, which is basically what orthopedic surgeons do their entire life.

The reason why many dentists or oral surgeons don't do bi-cortical engagement is that they should be using very long implants to engage the second cortical instead of a short implant, which engages the 1st cortical and is called unicortical engagement. Also, engaging the far cortical needs more surgical accuracy and dexterity, and so a very small number of dentists practice this concept.

Also, by engaging the pterygoid bone, which is positioned just beside the maxilla or the jawbone, there is an immense increase in the primary stability and cumulative torque value, and so immediate loading is very much possible.

At your dentist, Dr. E. Surendranath is well trained in all on 6 with or without pterygoids (depending on the available bone) and has done hundreds of all on 6  cases to date, and the majority of them are immediate loading cases, and a small minority is delayed loading, especially bin patients with osteoporosis, etc.

And with the latest advancements, we can do all on 6 with computer-guided implant surgery that gives more accuracy to the treatment process. A stent prevents the surgeon's drill from deviating to any other vital structure and directs it towards the maximum bone available.