Monday, October 22, 2012

Episode 398/500: Crown Removal - Richwill Crown Removal Tabs

There are a number of ways to remove crowns - not that you typically want to remove definitely luted crowns - but - there are the times when it "just has to be done".

Just like this morning.....

Chief Complaint: 55 YO female presents with a chief complaint, "my crown is loose - can you cement it back on?"

There are many things that run through my mind when a patient presents with this scenario, including:

  1. If it fell off, what's the success going to be if I just cement it back on?
  2. How many times has it fallen off?
  3. Did it fall off - or - did the tooth/core fracture?
History of Present Illness:  The patient's crown on tooth #13 (FDI #25) was dislodged over the weekend and caused some discomfort.  The tooth has been previously endodontically treated and the full coverage restoration was placed approximately 5 years ago.  

Clinical Exam: Tooth #13 crown was still intact intraorally and on the preparation.  By using an explorer and engaging the palatal crown margin and lifting coronally, I was able to start moving the crown.

Radiographic Exam:  Tooth #13 has been previously endodontically treated and does not appear to have a post placed in either canal.  Periradicular tissue is normal (radiographically)

So - the story continues - as I am about to remove the crown, I"m thinking that perhaps I had better capture a triple tray impression of the quadrant to ensure that if the crown/tooth fractures, I will at least have a "go-by" stent to fabricate a provisional restoration.  The other option is of course, to take/make alginate impressions - however - this is a sick parade/emergency patient and there really isn't time.  I suppose that as I reflect - I could have taken alginate impressions and rebooked her for another appointment.  Either way - here we are.

Anyways, long story short - the crown wouldn't come off and I suspected that she had fractured her core.  After provision of some local anesthetic (you'll see why if you look at the photo), I just couldn't get the crown off w/ hemostats (my crown removal forceps were at our other clinic). So, we scrounged around and found these friends - the Richwill Crown removers.  These are great little friends that only work in specific situations - and this was one of them.  Dental versions of jujubes, these guys, once heated and placed on the crown you intend on removing - make life just a little easier.  However, just like the instructions say - ensure that the opposing dentition is intact, or you may be removing a restoration from the opposing arch as well.

The little tag of tissue was most likely the culprit causing the patient some discomfort when the crown was rocked to the buccal.  This discomfort was also a great hint that most likely the tooth/core was fractured.

Now what to do?!

Here are the instructions for these green friends.
richwill crown remover, crown, removal, fractured crown, dental crown,
The crown removed from it's resting place of 5 years.  The white core material appears to be a composite core buildup.  
There was no post placed, and it's hard to determine how
much ferrule was used.

richwill crown remover, crown, removal, fractured crown, dental crown,

richwill crown remover, crown, removal, fractured crown, dental crown,
I'll be $4 that the little tissue tag was causing the discomfort when
I tried to remove the crown w/out local anesthesia.

richwill crown remover, crown, removal, fractured crown, dental crown,
Ok, the crown is off.

Now what?

Saturday, October 6, 2012

Episode 397/500: Endodontic Access Help - C+ files

I've moved into another clinic (with 12 other clinicians) and I'm really appreciative of the great things that I learned during my residency.  Such simple things that even now I take for granted - are either not shared with others - or - we have information/marketing overload.  "EVERY product is amazing" nowadays.

Our endodontic cabinet is an absolute zoo.  There are remnants of file systems and products from many other clinicians and I hope not to be one of those folks - but - I probably will.  So here I am, standing infront of this huge filled cabinet and I'm trying to determine what's required and low and behold, there are no #6 files.  Of course, there probably are folks reading this right now and think, "I don't even use #6 files".  Well, uhm....ok.

For the rest of us, there are #6 files and C+ files.  C+ files are just a little more stiff than the conventional #6 files and allow you to apply just "a little" more apical pressure.  Careful - these ones have a cutting tip and who knows where that tip may cut into if you're not diligent.

k file, c+ file, dentistry, endodontic file, endo file, mirror, ndodontics
C+ files in their little carrying case. Ever used a mirror with an endo ruler milled  into the handle?

k file, c+ file, dentistry, endodontic file, endo file, mirror, ndodontics

C+ files are made in the #6,8,10 and 15 file sizes.  There are, however, a few other files out there that appear to accomplish the same thing.  The first time I heard about them was today, when I searched PubMed for any literature on c+ files.

This literature article popped up:

 2012 Oct;38(10):1417-21. doi: 10.1016/j.joen.2012.05.005. Epub 2012 Jun 29.

Mechanical behavior of pathfinding endodontic instruments.

Try these and others out - they make just make that afternoon a little easier.

Sunday, September 30, 2012

Episode 396/500: Literature Supported Clinical Decisions

In the middle of searching the literature for justification of clinical decisions (pin retained amalgams, resin bonded amalgams, provisional materials), the guy from farnamstreet blog sends out this TED talk video.  BTW, Farnam Street blog is a great place for  all sorts of things - and - I like it b/c the tag line is essentially the same as me - "Mastering the best of what other people have figured out"  I have created essentially very little - but - I have been taught a huge amount and continue to learn from my colleagues everyday.

Although the speaker (Ben Goldacre) is talking about medicine, it is definitely applicable to dentistry.  The crux of the issue is that typically only positive results in research is published.  No one cares to publish negative findings (ie -voodoo magic does not disinfect endodontic canals).  That's obvious - or is it?

Let's talk about dental implants.  There is a tip in here, so hang on.  No patient wants a dental implant.  They want a restoration....... that is perhaps supported by a dental implant.  I know, I know - I hear what you're saying - that's an obvious statement you just made.
But, what I"m really talking about are anterior, implant supported restorations - the esthetic ones.  How many times have I looked at pictures in journals (I can't read) and the author has some photos showing his/her work and I sit back and think, "the esthetics probably could have been better managed using conventional fixed prosthodontics or removable prosthesis"  Wow, going back in time?
The industry is currently at a point where any edentulous parking spot in a patient's oral cavity should be restored with an implant.  In our clinical practice (which is much different from where a patient has to pay for something), each time a patient presents with an edentulous space - they already know enough to be dangerous regarding dental implants.  "Doc, can I get an implant?"  I hear that at least 4 times a day - and that's ok.  However, so many clinical variables have to be considered before treatment planning for the "sliced bread". 

Would your treatment option be different if the adjacent teeth were
heavily restored?

(You know, the best thing since sliced bread statement... )
 How many times have I looked intraorally and thought - I don't think I could have restored/placed that implant any better - but - this restoration looks like junk esthetically.  Is this the best we can do? 
I'm for dental implants - however - there is more to prescribing this treatment than appears in the literature.  The literature only talks about survivability of implants - that is - how successful the titanium screw is - not the esthetic component.  There are no long term randomized trials discussing implant esthetics - and - isn't that what the patient really wants?  

What's esthetics?  Well - just imagine your implant patient sitting and laughing out loud, having a great time with his/her friends and at one point, a friend points and asks- "what's wrong with your gums/tooth?"  (Perhaps alcohol is involved to aid in relaxation.)  "Uh.....nothing?"
The patient may have settled for the poor esthetics b/c they sat through 8 hours of tooth extraction, impressions, implant surgery, abutment impressions, crown placement, etc.  But when the rubber hits the road - they won't be impressed if their friends can see it and they spent $x dollars.

A study titled "Prospective randomized clinical trial of dental implants: Poor esthetic outcomes"
definitely wouldn't get published.

Care of :

If you were a manufacturer of dental materials would you want a negative finding published especially -  if you paid and sponsored that researcher to do that research?  Probably not.  The Endo Blog (where I picked up the implant crown picture) has a great overview regarding endodontics and implants.  I appreciate their aspect b/c I totally forgot about treatment options before the tooth is extracted.

Therefore, before rushing to prescribe an implant to "fill a space", it's key to understand that it is really the restoration that the patient wants.  Yes, 95% of the time, the implant itself (ie titanium screw), will function.  However - how likely are you able to place an esthetic restoration on top of that boat anchor?  Esthetics is key, and I am by no means a master of that.

So, what am I saying here?  Clinical practice is difficult.  You are bombarded with advertisements, sales persons, reps, continuing education - etc etc.  Now, it's apparent that even the literature is biased as well (we all knew that).  How to make a clinical decision?  Talk to peers, review the literature and treatment plan thoroughly based on your own experiences.  It's called practice for a reason - and - you won't know of those products that had negative results, yet, are still available.



Saturday, September 29, 2012

Episode 395/500: Polymethylmethacrylate

Melted Plexisand.

Did you know that Polymethylmethacrylate is also used to make Plexiglass? I had NO idea.  I found this out 4 minutes ago while I was googling plexiglass to fabricate exterior storm windows for our home.

pmma, jet, acrylic, dentistry, plexiglass, fish, plastic
This beautiful fish has more in common with my stained, smelly, used PMMA provisionals than I thought!

Wow, 10 years of dentistry and I'm almost 100% positive that no-one had told me that before.  I just texted Dr. BD, asking him this question, "Do you know what plexiglass is made from?" He replied, "melted plexisand".........haha.

So, that dentistry PMMA material that you either did use or still do use to fabricate provisional (or interim, as I'm learning yet another term for the restoration we all know as a temporary restoration) is another version of industrial PMMA that is used for many other things.

Is this useful - probably not.  I'm not planning on using a Jet acrylic kit to fabricate a sheet of brownish yellow plexiglass either.  

But, it was just something interesting!

Here is what I started writing for this post - this is for next time.

During the moments that I have free time to think about dentistry, apart from work and our lovely 3 busy young sons, I've been trying to figure out why and when people choose to either restore a patient in Centric Relation, Centric Occlusion, or Maximum Intercuspation.  I know - boring - but, my real question is this:

if we as clinicians can really actually obtain an accurate, repeatable maxillo mandibular relationship records.  What am I talking about?  Well, I now share an office space (meaning, a small closet with 3 desks crammed into it) with a new prostho residency graduate, a periodontist and down the hall is our oral surgeon colleague.  Dr. Big Daddy continually shows me new tips everyday - and - once we get our lab space sorted (it's unbelievably a sad situation) I can start shooting some more videos.  However, in the meantime, he is all over the following idea: meticulous this that and the other thing.  He is about exact clinical outcomes - no exceptions - including interocclusal records.  I then ask myself - can we reaally be kidding ourselves to think that we can obtain an interocclusal record on an edentulous patient that is repeatable, exactly, from one day to another.  I practice this on the drive home and as a dentate person, my bite slightly changes from one attempt to another.  Is this clinically significant?  Probably not....ok..I have to stop here, b/c, this really wasn't the intent of this post!  I'll get back to this.


Tuesday, September 25, 2012

Episode 394/500: Final Impressions - Use Retractors

How many times have I neglected to heed this advice?  Many.  I think I've finally succumbed to a simple technique that aids in preventing the of an indirect restoration preparation.

Use cheek retractors during a final impression to ensure that the light body (if you're using a dual phase technique) "co-laminates" (that is a sweet term) with the medium body/heavy body.  If you have no idea what I"m talking about, neither did I.  Monophase?  Dual phase?  Co-laminate?

Ok, first things first.  When you are taking (or making...I still don't know which term is correct) a final impression, get the patient to hold cheek retractors to keep the buccal mucosa away from the preparations/implants/teeth, etc. So you can see below, by using the cheek retractors, I'm able to keep the preparations dry, as well as adjacent teeth, depending on the type of impression you are making/taking.

Cheek retractors, final impression, crown, dentistry, dental crown, implant, pvs
Cheek retractors keep the cheeks out of impression taking..making everyone's life a little easier

Ok, so to clear up that dual phase vs monophase impression technique, here are the basics.


If you are using the same viscosity (ie heavy body/putty) for the entire impression (final denture impression), then it's called a monophasic impression technique.  One type of viscosity.

Dual Phase:

A great example is classic final impressions of fixed, indirect restorations such as a single unit crown.  You typically "wash" the preparation with a light body material (#1 of 2) and then use a medium/heavy body material in a custom tray/stock tray/triple tray to pickup the wash.  Two types of viscosity.

If at any time during the dual phase, moisture (from cheeks, tongue, etc), comes in contact with one of the "phases" - ie the light body, then the heavy body won't stick.  It won't "co-laminate" with the other phase (type).  Hence, the cheek retractors will help prevent that problem.

Next up - the dry angle and keeping the tongue out of the way.