Telescope crown, konus (conus) crown, or insertion coping?
Telescope crown, konus crown or conus crown, and insertion coping are all different names given to similar retention strategies for a removable prosthesis. They can be on dental implants or teeth.
Telescope crown v conus crown v insertion coping
Telescope v. Konus (Conus)
Telescope dental crown
- Primary and secondary telescope slide on top of each other, without a terminal lock position, really like shock absorber.
- Held by friction fit – no cement.
- Milled telescope is a ZERO degree wall coping and the superstructure is not cemented, it fits by friction fit.
- Resilience Telescope mimics the PDL movement of the natural tooth while staying in friction
- Patient can remove (easily?) and easy to clean
- Can do with 1-16 teeth or implants but 2-6 is ideal and 4 if all implants (best if spread out)
- Vital teeth better, non-vital tend to break
- They are bulky so if doing teeth can be esthetic issue.
- Can include questionable teeth and if fail easy to fix removable by reline
- 3-4 teeth=reduced palate
- Heavy chamfer prep of 1mm – need room for primary coping
- Step by step can be found here
I will add I spoke with Petra Gierthmuehlen after seeing her zirconia primary coping and PEEK secondary coping case. She states that in Deutschland they are not all zero degree and she will often just use what the lab tech is comfortable with. She also adds they are difficult for labs to do well. My personal thought is best for implant supported prosthesis with high smile line when maybe not planned for.
Konus crowns (Conical Crown)
Syncone is example at 5 degrees
- Designed to be patient removable but becomes difficult and maybe impossible over time depending on case and system.
- Walls conical, varying from 1 to 6 degrees maximum.
- Have a terminal lock that generates when the conical surfaces mate in the final position. Bad part is that means parts have no contact until fully seated.
- They lock into position so they require a physical force to separate them. If many units can become impossible for patient to remove.
- No cement.
- Arian Deutsch called them a nightmare at 2019 Lab Day Chicago and other techs chimed in always either too tight or too lose.
Insertion coping (aka the North American telescope)
- Angle bigger than 6 degrees.
- Cements on
- Non Precious, Zirconia, and many others.
- Cemented on for all or screwed if implant
- Galvano (gold plated?) or USIG (vacuum formed PMMA?) secondary sleeves, you can make the tertiary frame in Chrome Cobalt.
Dental research and useful links to learn about telescope crowns, conus crowns, and insertion copings.