Excess Cement Penetrating Deep into Gingival Tissue: Do Specific Implant Fixtures Prevent This?

Dr. F. asks:
I recently attended a lecture where the teacher showed some examples of complications that arose from excess cement being extruded from the crown margin and deep into the gingival tissue. He explained that since the gingival fibers adhered loosely to the implant fixture, there was no real impediment for the cement to be driven deeply subgingival. Do any implant fixtures with a particular implant surface coating produce a tighter seal around the neck of the implant that might serve as a barrier to excess cement penetrating down deeply? In one of the cases, the lecturer actually had an example of where excess cement had led to implant failure.

17 thoughts on “Excess Cement Penetrating Deep into Gingival Tissue: Do Specific Implant Fixtures Prevent This?

  1. you may use IAC by bicon, which is a cementless screwless system, also you have an option of cementing the crown extra-orally and then placing it with the abutment intra-orally, hence there is no question of cement overhang subgingivally.. .. ..

  2. you can use every typology of implant (included bicon, for the reason that frequently dislodges out and must be cemented) but you would ever have an excess of cement undergoing plus or minus in deepness of soft tissues. So the unique way to take off the cement is: use the ultrasound.

  3. Restoring doctor needs to control the position of the abutment/restoration margin as much as possible. Keep the junction at ideal position and not too subgingival, then clean up is much easier. Use a fixture level impression, establish the abutment contour and finish line on a mastercast with soft tissue analog. Then take a film after cementation if there is any question of cement left behind.

  4. I recently did a ar re-entry surgery in which nearly 70% of the bone had been lost. Cement was clearly visible on an xray. On re-entry I found gross mounts of Improv cement around the neck of the implant. It appears that Improv is cytotoxic at least to bone. I cleaned all of the cement out, detoxified the implant with citric acid, grafted the site with Alloss, placed a collagen membrane, and re-buried the implant. We will see if the treatment is successful in regenerating bone. My suggestion after this incident is to not use Improv, to use a radiopaque cement, and to take a radiograph after cementation.

  5. Any cemented implant with the abutment margin beyond 3mm subgingival is a problem. As mentioned above, you must control the planning and execution. 2mm subgingival is easy to handle and gives all the benefits you need. Otherwise, you cannot use a cementable approach. People like prefabricated abutments, but they are not always the best choice.

  6. Residual cement in an implant sulcus will create inflammation and often will contribute to crestal bone loss. Deep tissue placements of an implant should be avoided as much as possible. Where the implant does become deeply submerged, higher abutment collars should be used which will place the cement interface at about 2 mm. below the marginal gingiva. The cements that are most difficult to remove are the resin based cements and these should be avoided. Glass ionomer cements are easier to clean off as you can visually see the cement and this cement tends to dislodge in fracturable pieces. Some practitioners place a cord in the sulcus prior to cementation which assists in barricading off the cement from going deep into the sulcus. This procedure however often requires the use of local anaesthetic.

  7. I agree with Michael Affleck, do not use prefabricated abutments. Where I have to use a cemented restoration I only use custom abutments so that I decide where the crown margin will end up and it is always in an area that I can clean more easily. This does not irradicate the problem completely but it does make life a lot easier.

  8. You have hit on one of the main dilemmas of modern implant dentistry. It’s more and more of a problem especially with deeper implant placement and “Bone level” implants.

    Three main things need to be appreciated. First that there is a move away from gold emergence profiles and even titanium to zirconia, because this gives a better gingival reaction and gingival adhesion.

    Second, it’s really critical to develop the correct marginal contours of the abutment. They have to follow the rise and fall of the marginal gingiva. This way the crown margin never goes more than slightly sub-marginal, and cement removal is facilitated.

    Third is the type of cement. Some tend to crumble into pieces which are almost impossible to remove. Some flow very easily and are very hard to detect. My preference is for conventional Glass Ionomer which goes through a rubbery set stage which makes it easy for clean up.

  9. in agreement with both Michael Affleck and Mike Heads
    , whenever possible we always recommend a custom abutment for this reason in particular, deep submucosal interfaces are a chalenge when shaping a stock abutment, often the predetermined margin is too ‘low’. lately we are making more ‘Atlantis’ CAD abutments which are designed within the confines of a ‘virtual’ finished crown to give perfect marginal position coupled with ideal emergence profile, all helps with cement management.

  10. While I agree with most of the above, I will recommend you consider options that have worked for me. These are of course situation specific. I lightly coat the inside of the crown with a resin modified glass cement, seat the crown and immediately use a air water spray to rinse away the excess, wait the desired setting time and clean up conventionally. If I believe that I will have an abutment crown margin that is difficult to access then my first choice is screw retained. As long as the access is on the lingual or occlusal surfaces with the use of composite and opaquers the access hole is nearly invisible. IMHO

  11. I do not know of any cases where excessive cement has caused implant failure, but it is very possable that if an operator were not careful, it could start a gingival issue. I remove the cement as if it were a natural tooth. Sometimes you have to be aggressive, to a point.

  12. Excess cement oozing out at the crown abutment margin below the gumline for the sake of aesthetics has been an ongoing enigma in oral implantology. Thankfully, so far there seems to be few reported cases where this excess cement has stayed, strayed and caused chronic inflammation and even failure of the implant. Or maybe they have not been reported. Or maybe nobody has dared tried doing such a study because it might throw a spanner into the fast spinning wheels of the implant business. Nevertheless, the “critical margin” in oral implantology is an issue that must be addressed and I believe will be solved. The solutions so far offered are like not using cements at all like in screw-retained, friction-grip like in Bicon. And if cements are used…….blow them away before they set….ultrasonic excess away……scrape them away…..Xray to see if radio-opaque cement is used….and then do something aggressivelike to solve the problem…etc. Acessibility is a key problem here because you canna eyeball ‘em. An whatcha canna eyeball…yoou musta guessta…seeee! Boils down to some commonsense shoot what you can and God and the immune system take care of the rest…ah. One of my mentors said use good old Zinc Phosphate Cement cuz they ultimately dissolve away after some time…the excess I mean. Of course…use yer ‘ead and try to place just enough only so there will hardly be any oooooze…oK. And you can always place the critical margin above ground….I mean above gum so that you can inspect everything all round and knock of any dem old naughty inflammatory causing excess irritants. But there goes dag dem aesthetiks! Unless you have those nifty chameleon-like Zirconias!Ha Ha!
    Lastly, you can always place the critical margin exactly flush with the gum level and you can scale them all around off and maintain them regularly by running a floss all round like a hangman’s noose. Nuff said!

    Cheers!

  13. Hi,

    this why I don´t like cement retained crows….. From my point of view, there´s only one way: the old-fashioned very small hole in the palatal or oclusal so the cement can flow.

    hope that helped.

    José Rosa

  14. Why not use a screw retained restoration instead…
    Ideally, proper treatment planning and 3 dimentionally implant placement in correct location can allow screw retained restoration even in the so called “Aesthetic Zone”
    Also in case of cement retention, just adding a small amount of cement with a blunt probe circumferentially with a good retentive crown (which is generally not the issue in implant prosthodontics) could help over spill of the cement.
    Also cud use lateral hole which some abutments provide and add some temp bond for passive fit just circumferentially…

  15. One tip guys and only one tip which always work.I use a 2ml syringe( has ten markings 0.2ml each) loaded with ky gel.I put this in my ceramometal crown 1ml first and try it on my milled/prepped/non prepped abutment on the master cast.If no extrution I add 0.2ml eachtime unless there is extrution.I note this amount.I mix Kalzinol with Vaseline and use as my cement.Same syringe type and 0.2ml less than the noted amount.Never found any excess, no need to remove any.Tested on supragingival,slightly subgingival and more subgingival cases.A case report has been sent to BDJ.Good luck

  16. Dear Rosa,
    The secret tunnel might work to a point but it will not eliminate excess absolutely. There will always be some naughty cement that will just refuse to ooze through the designated hole and come out along the crown abutment margin and gatecrash the party. I like Khan’s idea more except that it does seem like a helluva detailed uncompromising steps.Thanks anyway.

    Regards.

  17. If you utilize a patient specific abutment such as Atlantis you can have total control and restoration is easier than conventional crown and bridge. The computer reads the exact topography of the tissue and expands the platform appropriately for the tooth position and places the margin at the position you prefer. Our standard protocol is 1.5mm sub g facial or buccal .75 proximally and just below the crest of tissue lingually.This allows you to be sure you are seated 100% and makes cleanup of luting material a breeze. You can use a vent hole but it is really not necessary when you have easy access.

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