Is it better to get a Bone Graft When getting a tooth extracted, if you plan to get an implant?

bone Graft at the time of extraction is a good idea. It helps reduce bone loss which happens to different degrees after extraction. Bone grafting after extraction is more predictable and a much easier procedure compared to bone regeneration and augmentation once the bone has been lost 

Studies show that bone will resorb more if the site is not grafted after an extraction than if it is. This tends to be more important in the anterior region of the mouth, as the pattern of resorption is more significant for the front teeth. As a general rule of thumb, it is important to bone graft because it will preserve the contours of the bone as well as the over-lining gum tissue. This will translate to a nicely shaped final crown contour that will prevent food impaction or unsightly appearance.

Hello,

The answer to your question revolves around the common practice oral surgeons employ of socket preservation. Socket preservation is a treatment that prevents the rapid bone deterioration that typically occurs after a tooth is extracted or lost. Oral surgeons are often able to perform a socket preservation procedure immediately after a tooth has been removed. This procedure is time-efficient because it saves the patient from needing a separate bone grafting procedure later when they’re ready for dental implants.

Hi:I usually recommend bone grafting after extraction to try to preserve as much bone as possible.  If there is a plan for future implant this is even more important since high percentage of the bone get resorted after extraction. Best,Dr. Maddahi

The reason bone is placed after an extraction is not because the grafted bone is stronger. It's placed so that you don't lose bone support after the extraction. It's meant to preserve the bone, since there's a degree of bone loss after an extraction. These days the standard of care is to place a bone graft into the extraction socket, though it doesn't necessarily mean that if you had teeth extracted without placing bone grafts, you're implants won't last as long and be healthy. 

Bone grafting is dependent on many factors. Each case is evaluated separately which is why your friend needed grafting and you didn't. It is very common to bone graft if the implant is to be done in the future.