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.


Saturday, September 22, 2012

Episode 393/500: Provisional Crown Repair

When we were shooting the block provisional technique of Dr. K, he continued on (to my excitement), to discuss one method of repairing a provisional restoration.  Keep in mind that he's using Snap - PEMA material and this may not work with bis-acryl.

Provisional Restoration Repair

In addition

Crown Margins

Dr. Big Daddy recently graduated from a prosthodontic residency, and by golly, he is excited to hand out hints as they come up.  Even though he's a prosthodontist, he mentioned a tip that he used for finding MB2 canal before his residency.  Once I find the requisite material, I'll post a video.

Most of us travel through dental school with the light on at the end of the tunnel - ie - you just can't wait to get out and do your own thing.  However, once you get there, at some point, you'll be wanting to learn more - useful things.  I"m going to backtrack during this post b/c several basic concepts that I learned.....I never really knew who coined them.  Is that important?  Not sure.  Here is a great review of basic concepts by Dr. John Kois in his 1995 article in Peridontology 2000, "The restorative periodontal interface: biological parameters"

Thursday, September 13, 2012

Episode 392/500: Endodontic Diagnosis and Terminology (AAE)

First, before reading the characters below, take a look at this great powerpoint from the AAE regarding diagnosis.  I have the link to the AAE and to my google docs.  Like everything in life, the AAE link will probably change and will render this entire post useless.  The Google Docs - I hope - will not!

aae diagnosis, tracing the fistula, fistula, endodontics, root canal

American Academy of Endodontists - Diagnosis PowerPoint

In preparation for a lecture next week, I was reviewing the literature regarding some of the small endodontic tips that I was fortunate to learn.  Some of those include:  

  1. Diagnostic Tips - I was reviewing the AAE site and came upon the powerpoint as shown above - wow - what a great overview.
  2. Radiographs - ie - how to describe what I see on a radiograph to a shark sitting in the room waiting to sink his teeth into any perceivable errors that I made - it happened often.  Also include a basic number of radiographs and when to take them.
  3. Root fractures - how to clinically and radiographically determine if there was a's dicey at best.
  4. Sodium Hypochlorite - used in full strength these days - but why you ask?  One article suggests that that dilution by 50% decreases its effectiveness by 2/3rd (Hand 1978) - but that's only one of a few.  Oh yeah, and, it doesn't matter if you use spring fresh either....I'll find that reference somewhere.
  5. MB2 findingMB2 discovery white board
  6. Gates Glidden Drill Sizes - I didn't wonder about the sizes ever.
  7. Current thoughts on File Separation -
  8. Shift Shot Assistance 

As well, I am intending on reviewing the American Academy of Endodontists Diagnostic Terminology.    Since it's publication in JOE (2009), it's slowly made its way into mainstream.  The terminology is broken down into a pulpal diagnosis and an apical (periradicular) diagnosis.

The following radiographic images are from a review article published in JOE 2009. Identify and Define All Diagnostic Terms for Periapical/ Periradicular Health and Disease States. Remember, a diagsnosis is a complete procedure and radiographs are an adjunct to a complete clinical exam.  (thanks dad.)


Normal pulp 
       A clinical diagnostic category in which the pulp is symptom-free and normally responsive to pulp testing.

Reversible pulpitis A clinical diagnosis based on subjective and objective findings indicating that the inflammation should resolve and the pulp return to normal.

Symptomatic irreversible pulpitis  A clinical diagnosis based on subjective and objective finding indicating that the vital inflamed pulp is incapable of healing. Additional descriptors: lingering thermal pain, spontaneous pain, referred pain.

Asymptomatic irreversible pulpitis A clinical diagnosis based on subjective and objective findings indicating that the vital inflamed pulp is incapable of healing. Additional descriptors: no clinical symptoms but inflammation produced by caries, caries excavation, trauma.

Pulp necrosis A clinical diagnostic category indicating death of the dental pulp. The pulp is usually nonresponsive to pulp testing.

Previously treated A clinical diagnostic category indicating that the tooth has been endodontically treated and the canals are obturated with various filling materials other than intracanal

Previously initiated therapy A clinical diagnostic category indicating that the tooth has been previously treated by partial endodontic therapy (eg, pulpotomy, pulpectomy).


Normal apical tissues Teeth with normal periradicular tissues that are not sensitive to percussion or palpation testing. The lamina dura surrounding the root is intact, and the periodontal ligament
space is uniform.

root canal, radiograph, xray, dental xray, bone, pulp, crown
Symptomatic apical periodontitis Inflammation, usually of the apical periodontium, producing clinical symptoms including a painful response to biting and/or percussion or palpation. It might or might not be associated with an apical radiolucent area.

root canal, radiograph, xray, dental xray, bone, pulp, crown, symptomatic, acute, periodontitis

Asymptomatic apical periodontitis Inflammation and destruction of apical periodontium that is of pulpal origin, appears as an apical radiolucent area, and does not produce clinical symptoms.

root canal, radiograph, xray, dental xray, bone, pulp, crown, asymptomatic, chronic, periodontitisroot canal, radiograph, xray, dental xray, bone, pulp, crown, asymptomatic, chronic, periodontitisroot canal, radiograph, xray, dental xray, bone, pulp, crown

Acute apical abscess An inflammatory reaction to pulpal infection and necrosis characterized by rapid onset, spontaneous pain, tenderness of the tooth to pressure, pus formation, and swelling of
associated tissues.

root canal, radiograph, xray, dental xray, bone, pulp, crown, symptomatic, acute,abcess, apical, periodontitis
Chronic apical abscess An inflammatory reaction to pulpal infection and necrosis characterized by gradual onset, little or no discomfort, and the intermittent discharge

root canal, radiograph, xray, dental xray, bone, pulp, crown, asymptomatic, chronic, periodontitis

But then I read this article (from the AAE website and published in 2009 (JOE) and I was confused - is it really supporting the current terminology - or not??


Wednesday, September 12, 2012

Episode 391/500: Endodontic Radiographs

Before the residency, I"ll be honest, it was infrequent that I made a habit of taking a shift shot radiograph to aid during my endodontic exam.  Yes, I know what you're thinking, but I have to be honest.  
I was talking with a new grad a few weeks ago - she was asking me about endodontic rotary systems, etc, etc.  I wanted to talk about the tooth she was about to continue her endodontic therapy on, and asked to see her radiographs.  I had deja vu - was I really looking at only 1 preoperative radiograph - just like I used to do?  Dang - hence the reason for this post.

Our endodontic mentor described an interesting case regarding a postoperative complication following calcium hydroxide placement into a mandibular molar....that somehow found its way into the mandibular canal (IAN)'s in the video.  The point is that there is probably a minimum number of radiographs that should be taken during endodontic therapy.  What do you think?

Further to this video, a viewer mentioned something about the possibility of a fracture into the furcation in the second photo.  I took a look at the CBCT shot that I have on this patient (I removed a non restorable implant from her earlier) to see if there was indeed any fracture.

So, here are a few more radiographs that I was able to pull up.  Can you see how the superimposition of the tooth onto itself (PDL space as well) could be responsible for that "crack" in the furcation.  I looked on the CBCT, but the resolution is too poor to be diagnostic.

What do you think?  We'll talk more next time.

Monday, September 10, 2012

Root Fracture or Root Superimposition

A viewer on youtube mentioned that perhaps there was a root fracture in the furcation of tooth #19 (FDI #36).  The video was in response to a discussion that I had earlier that day to a recent dental graduate - the topic - you guessed it - endodontics.  Specifically, she was asking about rotary endodontics and file systems - that's an opinion filled hornet's nest that I really don't want to get into here.  On that note, dentistry is like the rest of life - many things are based on opinions by experts who try to be justified by some "research"......don't get me wrong, research/evidence based dentistry is important.  My problem is this: just that how much of the literature is a true representation of what really was observed - or - was observed to fulfill a financial obligation to a sponsoring company...I've always wondered as Seth Godin wonders..."if everyone wanted a reliable automobile that gets them from point a to b - why wouldn't you drive a Honda?"  

Thursday, September 6, 2012

Episode 390/500: Dental Radiolucency Endodontic Diagnosis

Case Study:

Chief Complaint:  31 year old male presents with a chief complaint of "I"d like my front teeth fixed"
History of Present Illness: Patient was in a soccer incident when he was 14 years old.  The central incisor (#8 or FDI #11) was avulsed and not reimplanted at the time.  The patient has been asymptomatic ever since.
Medical History:  No Medications, no medical conditions, non smoker, BP: 115/65, Pulse: 72
Extraoral Exam:  Non remarkable
Intraoral Exam:  Soft Tissues non remarkable
Endodontic Tests:  (shortened version) #7 (FDI #22) tests non responsive to cold and EPT.  No percussion pain.  Miller mobility 1, Probing depths <3mm, no palpation pain, no swelling apical region #7.

What is your radiographic diagnosis for tooth #7 (FDI #12)?

fracture, root fracture, crown, radiolucency, endodontics, extraction, dental trauma
fracture, root fracture, crown, radiolucency, endodontics, extraction, dental trauma

fracture, root fracture, crown, radiolucency, endodontics, extraction, dental trauma

Endodontic Irrigation - Sodium Hypochlorite

This morning, I had a discussion with a relatively new grad regarding his endodontic irrigation protocol, "Dan, what irrigant do you use and when?"  Well Dan, as I'm finding out, there is controversy regarding almost everything we do in dentistry, including endodontic irrigants.  With that said, I believe that most of the practicing population would agree that it is the intent of endodontics to ensure a "as close to bacteria free" canal system prior to obturating.  Does that happen - maybe?

During our residency, we were guided to use full strength Sodium Hypochlorite (5.25% or 6% depending on where you reside in the world).  Again the literature is abound with opinions and some evidence and quite frankly, you have to

Wednesday, September 5, 2012

Endodontic Radiographs

Is there a minimum number of radiographs required during endodontic treatment?  I"m not sure there is an exact standard, however, I've b

Monday, September 3, 2012

Episode 389/500: Dental Emergency Kits

Annually, (above and beyond our BLS requirement), the clinic typically has a round robin afternoon where each of the clinic members (approximately 60 members) go through basic scenarios including anaphylaxis, syncope, seizure, MI, etc.

In the process of familiarizing myself with the clinic's medical emergency kits (ie the location of the oxygen tanks, emergency kits - and - the procedures for initiating the emergency medical system), I stumbled upon the bees nest also known as the medical emergency kit.  Now, I must be honest, this is the medical kit for a satellite clinic, and, it really needs to be simplified.  I've been in a few emergencies and the simpler the protocol and kit -  the better.

Keep it simple, stupid.

Here is an example of a card that can be put into a ziploc bag along with the appropriate medications.  I attended an amazing medical emergencies course put on by Dr. Haas a few years ago and I've never looked back with regards to setting up a medical emergencies course.
Please understand that protocols do change and if you're viewing this in the year 2290, things may have changed.

syncope, hypotension, dental emergency kit, medical emergency kit
Ziploc Bag example from Dr. Haas' superb continuing education course



Medical Emergencies in the Dental Office, 6th edition, Malamed
Dental Emergencies, 2007, Dr. Haas, University of Toronto

Saturday, September 1, 2012

Episode 388/500: Alveoloplasty Part 2

Here is part 2 in a 2 part series regarding the alveoloplasty for Aaron and his immediate denture.   There are a few learning points that are included in this video, however, overall - it's a fairly simple procedure.  Next time I'd use a continuous suture - less knots = less irritation under the denture.

D McT has taken over the case and I'm excited to see post "new denture" photos.  I believe that Aaron is currently being worked up to be presented to the implant board for 2 mandibular implants to support, retain, and stabilize some sort of mandibular prosthesis.

More to follow.