In yesterday’s post I looked at the thought process of using a screw retained versus a cement retained implant crown. If the choice is made to utilize a cement retained implant crown the next question is what kind of cement will you use. Many practitioners are devoted to the concept of only using provisional cements in these situations. Many others are very comfortable utilizing a permanent cement for implant crowns. So why do one or the other. the primary reason behind using a provisional cement is the ability to retrieve the crown and be able to access the abutment and screw. On the other side of the equation is using a permanent cement whose advantage is retention. Retention and retrievability are on opposite sides of the equation, and when you increase one you decrease the other.
Crown retention is impacted by additional factors such as height of the opposing walls of the abutment, abutment taper and spacer between the abutment and the crown. If your preference is to use a temporary cement, one way to increase retention is to work with your lab to maximize the mechanical retention of the abutment design. Esthetics can also be a factor and certain clinical situations will call for a translucent cement whether temporary or permanent. One factor is the ease with which the cement can be cleaned as excess cement left behind is a key factor in periimplantitis.
In a recent study of over 60 US dental schools, resin modified glass ionomer was found to be the most commonly used and taught cement for implant crown cementation. So what cement should we use? I’d like to sue the least retentive cement that keeps the implant crown in and does not necessitate frequent visits to recement. If I have any concerns I will start with a temporary cement. In these cases if the crown comes loose I will adjust to a slightly more retentive cement. In situations where I am not concerned about gingival health, occlusal issues or needing access to the abutment I routinely use a translucent SESP resin cement.
Dear Lee Ann,
For implant crowns, I found that the most risk factor is the submarginal retained cement. The closer this retained cement is to the fixture level, the bigger the problem. Lately I found myself choosing extraorally cementing the crown on the abutment, carefully removing all excess cement or even polish the margin if I choose to bond the crown to the abutment. Having an access hole for the screw, I then torque the the abutment& crown down into the implant fixture. Of course, this restorative choice implies a thorough pre-prosthetic survey of the implant site and almost always demands the use of a surgical stent. There is more to discuss about the impact on the soft tissue stability of the removal of a zirconia abutment placed, for instance, at the time of implant placement. For anterior teeth this is the preferred method of immediate temporization and studies have show the amazing tissue stability around the zirconia. Other authors postulated that with every removal of the abutment, tissue could recede 0.5 to even 1 mm. I removed the abutment on few case for the purpose of cementing the crown on it and haven’t notice a significant tissue recession. Maybe you can give me your feedback on this aspect.
Can temporary cement work on a zirconia crown?
I am sure there is more to your question, however crowns are retained with retention form and resistance form, or the mechanical interface between the tooth and the internal of the restoration. There is no difference between cementing a zirconia crown with temp cement, than any other crown made of alternate materials. If you have lots of mechanical retention you may have trouble even getting it off. If it lacks mechanical retention, with temp cement is will be off the prep constantly.
Dear LeeAnn, how do we cement a zirconium based crown onto a zirconium abutment which has been placed and torqued down on a metallic implant . Please explain steps. Many Thanks.
There are quite a few options to cement this. After covering the screw with teflon tape, I would try cementing it first with GC Fuji Temp, a temporary Glass ionomer cement. If you want something translucent I would use TempoCem ID.
I have lost my front tooth on the left side due to a fractured crown. The root extracted easily some 5 months ago and my dentist is concerned about the health of the bone. He has attempted a bone graft which has not worked. Isn’t there a suitable bone cement to strengthen the bone at the bottom of the extraction site in order to accommodate installing the implant pin?
I have lost my upper front tooth on the left side due to a fractured crown. The root extracted easily some 5 months ago and my dentist is concerned about the health of the bone. He has attempted a bone graft which has not worked. Isn’t there a suitable bone cement to strengthen the bone at the bottom of the extraction site in order to accommodate installing the implant pin?
There are a variety of bone grafting materials, and also numerous reasons a graft may not be healing as hoped for. Discussing this with an oral surgeon or periodontist who does advanced diagnosis and grafting would be my first suggestion.