Retrieve Cement: Solution for Removing Crowns and Bridges on Implant Abutments?
I have read about the new implant cement that Parkell has come out with called Retrieve. They claim it does not harden completely but hardens enough to retain cemented crowns and bridges on implant abutments. They recommend lubricating the coronal half of the abutment before using their cement. Since it does not harden completely you should be able to remove crowns and bridges cemented with Retrieve, especially if the coronal half of the abutment has been lubricated. Have any of you tried this product and does it work as they claim it does? In the past, I have had no luck in getting off cemented crowns and bridges, so I’m interested in any feedback on this product and/or any other techniques people have used with cemented crowns and bridges.
13 Comments on Retrieve Cement: Solution for Removing Crowns and Bridges on Implant Abutments?
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John Manuel DDS
11/27/2012
While the idea of a flexible cement is enticing, the longevity and performance have been disappointing. Also, I have read that there is not long term benefit from resilient cements and crown materials in implant restorations.
Personal experience with Retrieve has been tht the smaller crown preparations (2-3 mm diam) suffer early failure in that the lateral forces pierce the cement wall. Wider abutment preparations (4-5 diam) follow the same path with a 9-12 month delay.
It also seems to absorb moisture like the old Durelon and can allow the cement space to harbor bacteria before the cement failure becomes clinically noticeable.
As such, I have ceased using it. We will have to see what the experience of others is on this.
John
Barry Tibbott
11/27/2012
I have used both types of this cement: 'Retrieve' and 'Premier' both with quite good success. One of the overriding problems with cement retained prostheses is retained cement around the crown/abutment interface which has been shown to cause peri-implantitis. The beauty of these slow setting cements is that you can use a small amount of cement inside the crown, seat it fully and then remove the crown. the nurse can remove excess cement from around the crown while the dentist (under loupes with a micro brush) can remove excess cement from around the abutment. The crown is then re-seated without the danger of excess cement. However John is correct that with narrow abutments there is a danger of the crown de-cementing. In these cases a definitive cement can be used or a screw retained crown. hope this helps and good luck
Barry Tibbott
John Manuel, DDS
11/27/2012
The use of a small amount of a cohesive, non adhesive, cement, like Ketac-Cem, to the marginal few millimeters can be easily broken with a sharp tap. Also, it will come loose if a leak develops, which is very nice for implant situations.
If a slightly stronger bond is required, the Fuji Plus or Duet, compomer can work if applied sparingly. If used heavily it can be pretty permanent esp without Vaseline.
The old school used zinc oxide eugenol with some Vaseline in it. You could put Vaseline sparingly on the Ketac or Fuji cemented abutment tops. The easiest to remove is the Ketac Cem, even easier than the Retrieve if used sparingly on margin areas.
Robert Holt
11/27/2012
Please, no matter what your cement choice may be, make sure the cement is radio-opaque. This way, a post cementation radiograph will show excess. For example, Premier Implant Cement, the number one seller in the US, is radiolucent and a PA will not show it. This is a prelude to peri-implantitis.
Peter Fairbairn
11/28/2012
Hi Barry I agree these cements ( I have used premier in about 1,000 cases ) are easier to comtrol but the crical aspect here is the fashion to place Implants deeper and deeper ( I see Ankylos 5 mm subcrestally ) to improve "emergence profile " which is not actually a big issue in implants.
Whilst doing this is protocol for these implant types it does bring issues of cemetation to the fore leading to many crticisms of the cements rather than looking at techniques and often when that deep screw retained would be a better option.
Varing depth of placement is best dealt with varying abutment heights always keeping the cement interface at or just below the gingival margin where these cements can easily be cleaned of in the "rubber" phase.
Again it is always the Golf clubs fault .
Regards
Peter
John Manuel DDS
11/28/2012
I agree, Peter. The Bicon does have the advantage of being able to cement the crown to the abutment OUTSIDE of the oral environment, followed by seating the abutment to the implant via the Morse taper lock. This allows easy cleaning and even polishing if needed.
The depth problem with the Retrieve, in my experience, is that it does not seem impervious to oral fluids and bacteria. Perhaps the flexibility allows some capillary action between the internal crown surface and the outside abutment surface, but the long term result seem so harbor bacteria and exude their by-products at the margin over time.
John
CRS
11/28/2012
Isn't better to use screw retained crowns for retrievability and avoiding the cement issue? Cement causes perimplantitis and failure. If the implants can be placed for a screw retained prosthesis shouldn't that be the first choice? Please note that I don't want to take the comments out of context and sometimes cement retained is the only option. Thanks
John Manuel DDS
11/28/2012
CRS, et al,
You are correct in that cementing a restoration to a screw retained abutment will cause retrievability problems. However, cementing a restoration to a true Morse taper retained abutment (no screws) is no problem at all. The abutment and restoration can be retrieved with a simple twist and tap.
Whole screw retained abutments have advantages on near to surface locations, however, they can exhibit troublesome leaks when used more deeply in the tissues due to the difficulty in achieving a bacteria proof seal in threaded designs. The true 'ores taper locking abutments of Bicon seal so tightly that bacteria cannot penetrate and we often see bone growing up and over the abutment/implant junction.
I think what we are discussing in this thread are the various ways in which one can use cemented abutments in an easily retrievable manner since the classic, full cement loaded, manner is problematic, as you mention.
John
Chris Stevens DDS
11/28/2012
This comment is not about retrieval but rather excess cement and peri-implantitis. Please refer to the work of Dr. Chandur Wadhwani, a prosthodontist from WA. Search his name for his website and look for the pdf on cementation of implants. He makes and uses a "chairside copy die" to control excess cement. Wonderful technique.
Chris
Brad F.
11/28/2012
You all add great points. I personally prefer to use a "Permanent" cement for any cement retained implant case. My thought is that if I have any doubt about needing to retrieve a crown/abutment in the future I am going to use a screw retained restoration. I believe that the idea of an "implant cement" such as premier was developed during the external hex era where abutment loosening was a much more common problem. Now with internal hex I don't see many situations where I would want to retrieve a single unit ( or short span) restoration. On most longer multiple units, I prefer screw retained. For the very rare case that may need to retrieve a crown and have to cut it off, then I eat the cost of the lab fee but I also don't risk damaging the internal aspect of the implant or breaking a screw while trying to "tap" the crown off of the abutment. This is just what works for me.
Thanks, Brad
Richard Hughes, DDS, FAAI
11/29/2012
Everyone has made decent comments. I have found that in most instances a polycarboxylate cement works very well, next a ZnPO4 cement for times when retention is questionable. I do not use glass ionomers because restorations cemented with them are impossable to remove, unless you cut them off. Usually you have to cut off restorations cemented with polycarboxylates or ZnPO4 cements. I am referring to single units. Bridges are managed well with Fynal cement or a polycarboxylate cement. Some say that polycarboxylates cause corrosion of Ti. This level of corrosion is moot.
As for internal hexed abutments not becoming lose. They can, due to two reasons. First, the abutment was not properly seated. Second, the patients pare function over time can causenthe small screw to back out. Then you usually have to cut off the restoration and start over again, this is an ugly little fact.
Brad F
11/29/2012
True, I was not suggesting that internal hex abutments can not come loose. Rather that with newer technologies (internal hex, morse tapers, and better machining) as compare to the days when external hex was the only option, abutments come loose FAR less often. Of course there are exceptions to everything. But as far as "abutment was not properly seated" that is an operator error and should be redone anyway. As far as parafunctional patients hopefully those patients are wearing a nightguard and personally I would use a screw retained restoration in those cases because obviously some patients are non compliant with night guards. Yes abutments can still come loose and if it make you more comfortable to use a "retrievable cement" then that is what you should do. I personally prefer to cement permanently and redo the rare case that comes loose (I couldn't tell you the last time I had to. If your abutments are still coming loose frequently then I would consider switching implant systems
Richard Hughes, DDS, FAAI
11/30/2012
Brad, I agree with you 100%. I give all my fixed implant patients a night guard. I don't know if they wear them, but at least I practiced due dillagence. Fortunately only a very few abutments come lose, but when they do, it's a real pain in the neck. I even have one implant overdenture case (removable over denture) case in a night guard. This implant arena is not cookie cutter. We have to be ready for the unusual.
