Lower Molar: Surgical Extraction and Implant Placement at Same Time?

Dr. C. asks:
I have a patient who would like a dental implant to replace a lower molar. The distal root of the tooth has been removed, but a surgical extraction will be required to remove what is left of the mesial root. There is plenty of bone distally to place an implant. Can the surgical extraction be done at the same time as preparing the implant site and placing the implant? Or should the root be removed first and the site allowed to heal before implant placement?

21 thoughts on “Lower Molar: Surgical Extraction and Implant Placement at Same Time?

  1. Implant should be placed where it is needed, not where, there is bone.
    Remove the mesial root,graft the area and place wider diameter implant in the center(mesio-distally)of ridge at later date for better disribution of load.

  2. I agree with Dr. Joshi. However I had few cases where I did ridge preservation to place an implant later and later I lost some bone. Recently I am trying to place an immediate implant right in the septum (when the width is ok) and that will be ideal. I believe placing a wide diameter (4.5mm and up) towards the mesial or distal “40/60″ should also be ok. Again you can also bone graft and come later, but bone grafts are not always predictable (at least in my opinion). Good Luck

  3. I would just say NNNNNOOOOOO…. dont ever place implants in the lower jaw at the same time of extraction, ITS THE EASIEST WAY INTO A LAWSUIT for numbing the patients jaw.
    Better safe than sorry and if the patient wants a n inmediate implant do it the next day with or without graft, that is up to you.
    best of luck

  4. Dear Dr C,

    I always believe in the KISS method. To get a Predictable result, I would do the following:

    1 Diagnostic models with the molar waxed up to idea occlusion( as long as the opposing is not being restored)

    2 Surgical guide- I found that the best guide is acrylic with the pilot hole through the central groove and then cut to a thickness just above the height of the gingiva( hard to hit bone if the pilot stops due to the height of the clinical crown).

    Then remove the remaining root. Place the surgical template and drill a starter hole. Fully reflect the tissue and see where you are. If there is going to be a compromise, graft, and if not, place the implant. Implants are circles and a tooth crossectionally is rhomboid. The mesial root may only show the mesial threads of the implant and this is easy to graft and is very predictable as long as the body of the implant is in good bone and secure.

  5. I concur with Dr. Knecht in that with a surgical guide and proper drilling protocol, an immediate implant is very possible. If the mesial root is not too robust, then there should be sufficient bone on the mesial, lingual, and distal to stabilize the implant and prevent it from “drifting” mesial at placement. Review of the radiograph would give you that information. As long as the planned implant placement did not extend past the apex of the mesial root, then the concern expressed by Dr. Berg should not be an issue. Augmentation of any exposed threads on the mesial with Puros small particle cancellous bone ideally hydrated with PRP would work fine. Primary closure would be difficult to obtain and if you did, you would loose your zone of attached gingiva. If you achieved 35-45 newtons of torque, a healing abutment would be appropriate.

    Of course, if you wanted to KISS, then socket preservation and place in 2 months.

  6. I think that Dr. Knecht gave an excellent input.
    Dr. Berg, can you please explain your rationale behind your comment? I dont understand why will an immediate placement result in a numbing jaw? Unless you are very close to the IA bundle and I think this is a totally different story.
    Thanks

  7. GET A CT SCAN DONE FIRST and you’ll know exactly where you are going and how much bone there is before you extract the tooth if an immediate implant placement is desired. If there is sufficient bone to stabilize the implant, you can place the implant immediately upon extraction. Graft the socket area around the implant. Surgical guides should be used as needed for proper placement. Injury to the inferior alveolar nerve should not be any more a concern for this than any other mandibular posterior implant placement.

  8. Placing the implant at the same time as the extraction can be performed judiciously and safely depending on how much bone is in the furcation in order to get a good result. The more important question and issue regarding this case is the age and gender of the patient. Implants should not be inserted into teenagers until the best determination is that there will be no more growth. If the patient is female, maybe growth has ceased by age 16. One needs to look at the parents and consult with the orthodontist. If it is a male, the chances are too great that there will be a growth spurt. If the implant is inserted and then the jaw grows, the implant functions like an ankylosed deciduous tooth and the occlusal plane will be off. A serious of problems could occur, all of which are avoidable if the implant placement is delayed. Eighteen is usually the youngest age to insert an implant in a male.

  9. Dr Berg ..Im not sure what you are talking about?
    There is no greater risk of nerve impingement post ectraction or by delayed placement

    Extraction immidiate placement is practiced so widley now it is considered routine

    I agree with Dr Joshi for good placement wait for the simple graft to heal ..so what you get your crown 2 months latter ?
    This is without question the best way and what I would do in my mouth

    Only in cases where Im doing a lower jaw clearance and immidiate placement for a multiunit bridge I would not be concerned if molar placement is 2mm mesial or distal

    Re CT scan pre op ..I dont see the point
    Your surgical site is relevant AFTER the tooth is extracted not before
    What if the extraction takes out part, or all of the interdental bone or some of the wall of the socket ?
    Now the scan is worse than useless

  10. Several comments come to mind. There are so many different opinions it is hard to gleen the wheat from the chaff.

    I agree that immidiate placement is routine and well accepted. I have been doing this for several years and the success rate has been excellent. There are of course situations where the condition of bone requires reconstruction with a graft. If such is the case I would consider more then two months to let this graft mature. I would suggest more like 4-6 months before placement.

    Regarding growth potential for younger patients. If you want to be safe I would suggest requesting wrist bone films. I have seen 18 year old male grow until 20+. If the wrist bones are closed the growth is over. Most Orthodontists can either take these films or tell you where to order them.

    In most cases a template, guide, stent
    should not be needed. The extraction socket defines the location and placement. Also unless radiographs show close proximity to nerves or sinus ect save the c.t scan.

  11. Dr.SS is correct.Ct scan prior to extraction will not be as useful as architecture of remaining ridge will be different after healing.
    For posterior single tooth implant,Surgical guide is also not must.
    Just follow opposing occlusion and adjacent teeth,try to place implant in interredicular bone which is better quality then grafted socket.

    I do not see very good reason to rush the case and take extra risks of failure.

  12. What is the general consensus as to how long we wait after grafting/socket preservation?
    Osurg talks about 6 months …socket preservation in a lower molar ??
    I respectfully disagree that while 6 months does no harm for a socket preservation it is not necassary

    Im going into grafted sinus before 6 months..

    Dr Joshi you had the first comment in this dialogue
    How long are you waiting before you place that implant after socket preservation /grafting and haow does it vary according to site in your view
    Thanks

  13. Dear Dr.SS
    In my opinion waiting period variation depends upon graft materials we use rather than site itself.Site may be playing role,due to different morphology of bone at different sites,which I am not aware of it.
    But as a general rule in nongrafted sockets or sockets grafted with mineralised cancelous bone (cadaver)we usually go back in 4 months,while sockets grafted with bovine bone like bio-oss we wait for atleast 6 months.
    To be honest I find better quality of bone with cadaver bone.
    I do not like to use TCP.Some other faculty love TCP.
    In molors we do not try to have primary closure if all walls are intact,instead we cover with RCM.

    Most of my residents place implants in 4 months.

  14. We have very distinguished faculty very experiennced in socket preservation named Dr. BOb Horowitz who already have spoken about it in details few months ago.You can contact him about site specific variation,He does do hisological studies.

  15. Use a wide diameter implant to obliterate the socket – distil root prob has bone developed put the implant in the correct position – avoid non autogenous materials osteoblasts will “jump” upto 1mm and integrate – we do no put materials in sockets to aid healing do we !! therefore why put any material here.Assess carefully after extraction a CT is worthless pre op as it will depend on how the root is removed calibrate a OPG and stay 2mm clear of the IA nerve . If the xla is traumatic wait 4-6 months then re assess and place – tell your patient you may place the implant or not dependant on what the extraction is like and consent them for every eventuality – good luck hope this helps

  16. If this was my patient, I would take study models.I would visualize on the model,( check the occlusion with opposing tooth); and pencil the mesial-distal dimension of the proposed molar.Drill a hole in the stone model where the ideal site for the future implant is to be placed.

    Place a small piece of a round stick ( a wooden cotton stick applicator is fine) into the hole, and build an acrylic tooth on it. Drill a small depression into the occlusal surface of this acrylic crown where you want the implant to be placed.

    Make a surgical guide using a vaccum former ( such as the machine you use to make bleaching trays or mouth guards).

    At the time of surgery,( the patient is completely prepared, and premedicated) before any extracting or reflecting of the tissues, place acrylic into the void area of the tray, and seat in the mouth.

    Once the acrylic is set,remove the tray from the mouth and drill completely through the occlusal depresion on the proposed molar, and this will be your guide.

    Anaesthetize the patient with local anaesthetic, using buccal and lingual infiltration only…no mandibular block is necessary.

    Place the plastic shell over the lower teeth, and drill a pilot hole through the acrylic crown that will penetrate the mucosa and a few mm into the underlying bone.

    Remove the tray, visualize the puncture hole, and drill sufficiently down to seat a titanium measuring pin ( usually 5mm in the bone when seated).

    Using an XCP to firmly and accurately hold the radiograph film, shoot and develop the film.

    The film will show you exactly where you are, the mesial root still in place. You will then decide if there is adequate bone available for the osteotomy in the mesial-distal dimension, and how much bone you have vertically.

    If there appears to be adquate space, simply use elevators and periotomes to flip out the mesial root; complete the osteotomy and save the autogenous bone you will harvest from the drilling, to be used in the graft mixture.Place the implant,pack in the graft and cover the mesial open hole with a resorbable collagen material and suture into place.Keep the implant buried for 4-6 months

    If there appears to be inadequate space, then remove the mesial root, and graft as suggested above and wait 4-6 months before implant placement.

    No reflecting of soft tissue is not necessary so that the blood supply to the area is not interfered with, and a lightly anaesthetized area, without a block is sufficient and will be a good indicator if you should drill too deep.

    Gerald Rudick dds Montreal, Canada

  17. I agree almost totally with Dr. Joshi, Don’t do an immediate implant here in a 16 year old undergoing orthodontic treatment. Extract the mesial root and augment to preserve ridge dimension. Allow orto tx. to finish and then send for a tomogram. When the patient is old or mature enough, place the implant into the center of the space mesio distally.

    Immediate implants are routine and predictable in the right location. I personally never do immedinte fixtures in a molar site. Why compromise position or take a chance on incomplete bone regeneration on the exposed side of an implant in a wide socket?

    If a socket is augmented with Bio Oss, wait at least 6 months. Even then it will still be of questionable quality/density compared to natural bone healing or even allograft bone. I would almost always prefer to use cortical crushed allograft when socket augmentation is indicated because it results in a better quality implant site much more quickly.

    Good luck with your case. Steve

  18. Would anybody care to comment on immediate placement in sockets of mandibular premolars? There is no septum of bone to engage. How wide a diameter can you go to engage lateral walls? The mental foramen is very close by especially at the apex of the first premolar. What has been your experience?

  19. In a lower permolar situation I always get a tomogram first so I know exactly where everything is situated with relation to the root socket. If the inferior alveolar or mental nerves are too close, an immediate implant is not an option for me. I rely on extending the osteotomy about 3 mm beyond the socket in order to provide initial implant stability.

    In most immediate implant cases, which for me are only in single rooted tooth sites, I use a 5 mm diameter implant. On occasion it may be best to use a 4.0 or 4.3 mm diameter for a small tooth or as large as a 6 mm diameter for a very large tooth. It is not necessary to fill the entire socket with the implant. In fact in the maxillary anterior I prefer to leave some open space(0.5-1.0 mm) on the labial surface of the implant and allow bone regeneration to give a thicker labial plate over the implant.

  20. When conditions are right, I routinely surgically extract mandibular molars and place immediate implants. The key is to have some primary stability. If I can place an implant into the mandibular molar extraction site with primary stability, I will graft the site with FDBA and cover with a resorbable membrane. I then advance the flap to obtain primary closure. This is a bit technique sensitive. If you are not used to significantly advancing flaps for coverage, this may be difficult to perform. Additionally, it is a bit tricky to place the implant in this situation. As you are only placing the apical portion of the implant into existing bone, you must be very exacting with your osteotomy preparation. Preparing an accurate osteotomy in a narrow septum is not as easy as it sounds.

    With this technique, it is imperative to take accurate measurements concerning the IAN. If the IAN is too close to the tooth, you will not be able to extract the tooth and attain primary stability in an immediately placed man molar implant. There simply is not enough bone between the extraction site and the nerve.

  21. GSquare Says: February 10th, 2008 at 11:12 am
    Would anybody care to comment on immediate placement in sockets of mandibular premolars? There is no septum of bone to engage. How wide a diameter can you go to engage lateral walls? The mental foramen is very close by especially at the apex of the first premolar. What has been your experience?
    +++++++
    I have used implants up to 5 mm in diameter to engage socket walls without any difficulty. In fact, the width of the mandibular premolar at the CEJ is 5.0 mm according to Ash and Nelson. Typically, the insertion torque and initial stability of these fixtures is very high. Depending on local anatomy and your preference, you can use straight or tapered implants. This is not to say a 5 mm wide fixture can be used for all mandibular premolars. A smaller tooth and space width will require a 4 to 4.3 mm fixture.

    Also, as I stated earlier in this thread, a CT scan before the tooth is extracted can be very helpful if the intention is to place the implant at the time of tooth extraction. The apical aspect of the implant can be directed lingually away from the mental foramen, and in certain instances can engage part of the inferior lingual cortex of the mandible for additional fixation in some mandibles, which may even extend apical to the path of the inferior alveolar nerve. There are a number of variations in mandibular shapes that can be used to your advantage in immediate implant placement that you’ll never know about unless you take a pre-extraction CT scan.

    Usually these are placed as a single stage and a 5 mm wide healing abutment is generally placed on these implants. I generally use a straight emergence impression coping (no flare) on a 5 mm wide fixture in premolar sites.

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