Basic Implant Prepping and Customizing Help

[TripL3]

Hey!

I am a 5 year exp tech (primarily C&B waxer and e.max/metal framework) who was just recently introduced to implant fabrication and I was just wondering if anyone knows any books or sources for where I can obtain basic to advanced info on the fabrication of implants. I've fab'd billions of cementable restorations on implant abuments but only until recently have I done preps on titanium abutments. I've been doing the preps with a high speed handpiece with 2 kinds of carbide burs (FG-558, FG-1158, never done milling or CAD/CAM) and fabricated several custom abutments. I have trouble making them parallel, and aren't entirely sure what tools to use. The only knowledge I've had was from previous in-person observations of fellow experienced co-workers working on them and a few tips on how to do it.

Yes, I am a pure amateur at this, so please excuse my epic fail on implant knowledge

I'm specifically looking to know the official 'textbook' method of implants such as:

- knowledge of the several aspects regarding the implant such as the analog, impression coping, soft tissue models, etc
- implant identification
- parallelism
- single and multi-abutment comprehensive prep guide
- what a surveyer is
- how to use a surveyer
- margin guide
- in-depth guide to customizing, sprueing, casting, and finishing abutments
- anything else I should know

Even small bits of advice, or 1 sentence tips will be appreciated! Thank you DLN community

 

[Jo Chen]

Genieoss

 

[Brett Hansen CDT]

JoChen's site is a great resource.

-I started doing what you are describing 6 years ago. For parallelism with one abutment...you need to survey your abutment to the adjacent contacts so your resulting crown will have a path of insertion that will have optimal proximal contacts. For multi-abutment cases, every abutment must be parallel to each other. I usually will set the surveyor up by using the most troublesome contact from the teeth adjacent to the restoration site and then make sure every abutment I adjust is at least paralellel to that. We have a surveyor from Ney. It is simple and the manual will help you get started.

-For margins, most of the information I have read says you want to be about 1.5mm sub-gingival on the buccal/facial of the abutment and then around 1mm for the mesial, distal, and lingual. Some docs prefer a margin on the lingual to be slightly supra-gingival to facilitate the removal of cement.

-For occlusal reduction, you want to give yourself sufficient room for whatever type of restoration you will be fabricating. You also need to make sure that you do not reduce the abutment to the point where it won't have enough retention for the cemented crown.

-For single abutment cases, you need to make sure your final adjusted abutment has adequate crown retention. This is accomplished by cutting a flat side into the abutment...I usually put in on the buccal side of the abutment because that will give me more room to make the restoration more esthetic.

-I rarely do UCLA or cast-to abutments anymore. I do a lot of Atlantis custom abutments. They are a great company if you are new to custom abutments. One trick I learned for investing UCLA abutments is to take some very thin wire wax and insert it through the waxed up abutment. Then fill the ring slowly with investment until it is just covers the top of the abutment's screw-channel. Then slowly remove the wire wax and fill the ring to the appropriate level. This will make sure you don't get any air bubbles in the screw channel.

-Finally, I would find out what types of implants are used predominately in your area and then call those implant companies and get lab procedural manuals from them. You should also get the names and numbers of their sales reps. For some companies, I have found them to be very helpful.

Good Luck!

 

[Brett Hansen CDT]

One more thing, I use a Universal Cutter from NTI for the majority of my abutment adjustments. the one I use is cylindrical with a round head. It cuts a nice margin and a good flat side for retention. The MFG. No. for that bur is UC293E. It is about 25$ in the Zahn catalog and the last one I had lasted me a year even though I adjust about 5 abutments every week.

 

[TripL3]

Thank you! I'll have to read up more on surveying. Although I'm still lost on what actual tools to use step-by-step. The Genieoss guide gives me a brief description but not enough to fully understand. At times, I was advised to make a heavy shoulder margin as well, and I'm not quite sure what tools to use to do it efficiently.

From what I know, I believe it's in this order?:

1. Mizzy wheel to do the majority of the occlusal reduction.
2. FG-1158 Carbide Bur to set margin.
3. FG-558 Carbide Bur to set abutment into correct parallelism.

And I'm clueless on how to actually finish the abutment. From my knowledge, I've seen others use polishing wheels and points to numerous burs including the one you mentioned, Mr. Hansen, to finish the abutment. If it's not too much, can you share with me what tools you use for each step of the preparation? (Along with what #'s, sizes, etc each tool is -- if you can)

Either way, thank you very much for sharing your experience with me Mr. Jo Chen and Mr. Hansen.

 

[Brett Hansen CDT]

I don't polish the adjust portion of the abutment. I leave it rough to help with cement retention. I use the same grinding wheel I use to remove the sprues from copings to do large occlusal adjustments, then I us the long bur I described above to do everything else. The type of margin I leave on the abutment depends on the type of crown I will be making and how deep the interface is below the gingival crest.