Narrow implant or Wide Implant with GBR: How do you decide?

Always the 3.5 in this situation , the Implants never fail but the bone does, so the more TRUE host Bone not remnant particles the better . This bone is critical for the presence of attached gingiva ( not merely keratinized tissue ) which determines long term success of the case . Peter

Peter's comments are well taken, but I take into account the age, physical status of the patient and the morphology of the bone site for the grafting. I like to use expanders and growth factors to generate new bone, I also stage when necessary. I agree that more bone is optimal not more implant a wide implant takes up more real estate that could be bone. The "grafts" unless autogenous are really just spacers while the body regenerates new bone and there are definite limitations to what we get. You are not going to get attached gingival around an implant there is no PDL. If you have a narrow emergence profile in the posterior maxilla, food can pack in the area. So I don't have a pat answer I can vary the implant type 4.1 in this case with some expansion and growth factor grafting. Often a CT graft is necessary to keep the area healthy long term.

If you place a narrow implant in a molar site, there will be a discrepancy between the occlusal table of the molar and the diameter of the fixture, which will have a high susceptibility to peri implantitis in the future

This is a subject that I have been researching for the last five years. I got into the implant process by taking a residency at University of Oklahoma to learn about the use of small diameter implants (MDI's) to support a lower denture back in 2002. I have since used these small diameter implants to replace one tooth, for molars I use two, I've been very successful using these small implants. I've put three or four in the bone to replace two molars. I've used 8 or 9 and made a round house cemented to them and have been successful. Over the last 5 or 6 years I have been using root form implants that are 3.5mm -6mm wide successfully. But the question I always ask the instructor is "will the restoration last longer with a larger diameter implant so there is more integration surface for the bone and implant or is a smaller diameter implant going to be better because there is more bone/bone cells/and blood supply to keep the tissue healthy? Cost and agravation is an issue as well as time to get the new crown in place. Often it is quicker, less agravation and less surgery, and lower cost for the patient to use the smaller diameter implants. So I am a fan of smaller size implants where the larger ones won't work.

Bone expansion can often be used to place an adequately large implant to be able to transfer the load to the bone and not bend under function. The problem with skinny implants is their restoration. The options are usually limited, and we know that skinny implants will usually require a prosthesis with downward facing margins (limits margin design) and will depend on the prosthesis to create the entire emergence profile from a subgingival position? Where do you think the excess cement will go? How are you going to clean it out? Go to www.ReverseMargin.com to find out more about the "Gingival Effects" - how the Gingiva causes subgingival cement projection. Emil

If forced to use a smaller than optimal diameter implant to restore a molar site, instruct your lab to make the crown with a narrow occlusal table to minimize load. All we really need in most cases is to have a positive occlusal stop. If you explain this to the patient they will accept a "small" looking molar. We are trying to achieve function in these cases and not esthetics. I don't understand the previous post about "skinny" implants. The diameter of the implant has nothing to do with emergence profile and/or cement retention. Physiologic profiles that are maintainable by the patient can be achieved with any diameter implant and good prosthetic design

There are way too many "lollipop" implants out there....narrow diameter implants that have been restored with supposedly phsiologic crown contours.