Is temporary cement on an implant crown normal?
Seattle cosmetic dentist Lance Timmerman DMD in Tukwila is often asked if temporary cement for a permanent implant crown is normal. While it may not seem intuitive, temporary cement IS common, although the temporary nature is not the goal. This “temporary” cement is used “permanently”.
Old dental implant design
When implants were first developed, they looked like a nut was welded on top of a bolt.
This was called an “external hex” design. In order to make room for the restoration (crown or bridge), the height of the hex was limited and allowed permanent crowns to wiggle microscopically. Over time this movement would lead to the internal screw that held the crown in place with the implant to becoming loose. Loose screws would need to be torqued, or tightened, in order to stay put. We dentists needed to have access to the screws for routine tightening, often as frequent as every year.
Modern dental implant design
Someone had the bright idea to have the “welded nut” put on the inside of dental implants, what is now called “internal hex”.
This design allows a much larger surface area of the hex and is much more stable. The internal screws rarely become loose anymore so easy access is no longer necessary. However, old habits die hard and “if it ain’t broke, don’t fix it” approach is common in dental offices. A desire to access the implant screw remains, so temporary cement remains common in securing permanent dental implant crowns.