Sinus Lift Bone Graft- How Big Should the Implant Be?

A sinus lift bone graft is common!

What is a sinus bone graft?

The sinus is a hollow space above your upper molar teeth. There is usually not enough bone to place implants. The sinus lift bone graft builds the vertical height only. It does not build width. And it only builds height internally… Not externally where you can see in your mouth

There are two main types of sinus lifts.  A lateral window sinus lift and an internal sinus lifts.

Having implants that are not too short on the upper back teeth is important to longevity.

The left side of the image is the lump of bone I created in the sinus.

If you avoid the sinus lift and place really short implants, they are likely to fail.

What size should an implant be in the sinus?

Ideally the implants are no less than 4.7mm wide in the sinus. Also the implants should be no less than 10 mm tall.

A very normal size implant that I place place in the sinus on a daily basis is a 5.2 x 13 mm or a 5.2 x 11.5 mm. Sometimes a very wide jaw will accept a 7.0 mm diameter.

Of course there are exceptions where biomechanically a shorter smaller Implant may be able to be connected to a larger, longer Implant to make up for it.

In two decades of doing sinus lift bone grafting both lateral window and internal I can tell you that size matters.

That being said bigger is not always better!!

I also find that many  less trained dentists try to avoid this procedure and push the limits of the closed/internal version of the sinus lift bone graft. This technique of trying to go beyond the limits of what internal sinus lifting can do often ends up with failed implants and torn sinus membranes!!!

Both the lateral window and internal/crestal approach are both very good. I do both of them. The problem is when somebody only knows how to do one version that particular technique is pushed too far and Implant can end up dislodging and get stuck in the sinus…I remove one last week for another dentist

Ramsey A. Amin, D.D.S.

Diplomate of the American Board of Oral Implantology /Implant Dentistry

Fellow-American Academy of Implant Dentistry 

5 thoughts on “Sinus Lift Bone Graft- How Big Should the Implant Be?”

  1. Dear Dr. Amin,
    Thanks for all the helpful info you provide. My tooth #3 was extracted in 2021 after yet another infection after multiple apicoectomies and root amputation over the years. At one point infection spread to #2 at its root level so #2 had to be extracted as well. I understand why I need a sinus lift for an implant for #3, and periodontist recommends mixture of bovine xenograft and allograft to maintain height for a 10-mm implant. My concern is transmission of prion diseases, like Creutzfeldt–Jakob disease (CJD) and Alzheimers, from bovine and/or human donors. The disease-carrying prions cannot be inactivated or removed. 1) Am I right to be concerned? 2) Can you point me to sources from graft manufacturers that guarantee their human donors were free of prion diseases? (For bovine xenografts, Geislicht at least seems to use Australian cows that have no history BSE.) 3) Do you ever use equine bone-grafting material which seems to not have any risk for BSE? What is the product name for the equine bone-grafting material?
    4) Can I have an autograft instead for the sinus lift? I’ve been told autograft resorbs too quickly for a sinus lift by periodontist, but I keep reading in dental research papers that “autograft” is the gold standard. It’s frankly confusing. (No implant is being mentioned for #2, because, I am guessing, the tooth opposing #2 has been removed. It grew in sideways—childhood orthodontist removed normal molar and let wisdom tooth grow in sideways. This sideways tooth was yanked at the same time as #2.)
    Thanks for your time and consideration!
    Kind regards!

    Reply
    • Hi Tess,

      I love your detail 😃

      The bone bank I have used for 21 years uses gamma radiation which is beyond lethal to anything. I understand that no one really knows 100% but allografts have been safely used for a very long time. Xenografts such as bio-oss are manufactured to a very high standard as well.

      If I were you I would use autograft only along with PRF. It does dissolve a bit faster but to change the dynamic of resorbtion you have to harvest it in a different manner. The bone cortex needs to be harvested and not just the marrow. The reality is most DDS don’t know how to do this and there are not a lot of patients that want it that way! 😢

      I have done tons of autograft only sinus grafts. They work but you can’t do it the same way as we did in the 90’s! This way you don’t have to worry about prions! I just did an implant bone graft on my mom and used some allograft though!

      #2 likely does not need to be replaced and here is why.

      Reply
  2. Hi,
    I had a failed root canal, had the tooth extracted (upper back tooth 2nd from last), and had a bone graft at the same time as the extraction.

    Fast forward 4 months to my follow up appointment today. I was told I would need a sinus lift before they can put in an implant.

    From what I’ve read, a sinus lift is basically another bone graft. I am confused as to why I would need ANOTHER bone graft?

    Reply
    • Ahh. The first bone graft only preserves the width but did not add height.

      When I do this procedure I add beight but in reality very few dentists are skilled enough to do that at the same time.

      Sorry 😐

      Reply

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