The Endo Fix

Category: Daily Fix

Blue Light Special

Daily Fix

The intersection of scopes, filters, composite, and light can lead to some confusion and possibly unsafe clinical habits. So lets get the whole story straight and make sure our working habits are healthy as well as productive.

Light cure composites set when they are exposed to a light energy at a set wavelength of light. The composite has a photo-initiator called camphorquinone and an accelerator. The activator present in light activated composite is diethyl-amino-ethyl-methacrylate (amine) or diketone. They interact when exposed to light at wavelength of 400-500 nm, i.e, blue region of the visible light spectrum and cause the composite to set.

Sunlight, ambient light, and all other white light have the entire spectrum. So in the operatory, the ambient light will have enough blue light to make composite eventually cure. And your scope light with all its fabulous power will totally cook your composite. Additionally, the blue light with its low wavelength and high energy has the potential to cause harm to your eyes. Macular degeneration, retinal problems, and possibly cataracts are on the table eye damage wise. In addition, blue light is believed to affect mood and sleep among other things. Fortunately, there are filters that filter out the blue light.

Looking at the color wheel which represents the colors (ROYGBIV) and their opposites, you can see the opposite of blue is orange. So these orange filters will filter out the blue light.

Which comes in super handy when working under the scope doing composite work:

We do all our bonding using the orange filter in the scope. And here’s where some people get bamboozled.

Awash in orange light it’s easy to think that your scope filter is protecting you during the cure process.

Oh contraire monfraire!

If you were to remove the light from the back of the scope, and hit a cure, you’ll notice there is no difference whether the filter is applied or not.

The filter isn’t in the column at all. Its where the fiberoptic/liquid cable enters the back of the scope.

It’s this little guy here…

So when it’s time to cure, either look away out of the scope or don some protective eye wear.

In the case of performing a custom resin matrix, its eye wear for the both of us. Routine composite work, I usually just close my eyes till I hear the beep.

Dens Invaginatus

Daily Fix, Large Lesion

Sometimes the development of the tooth goes a little haywire and another tooth begins to develop within a tooth, but not completely. So we end up with this invagination leading to the pulp and sometimes it doesn’t completely close off. Such a situation set the pulp up for an early death as can be seen here by the lack of root development and divergent open apices. Here we have a a pretty large finding imaging wise and a swelling. We changed the calcium hydroxide medicine out over 5 months and ultimately filled the apical 5mm with MTA and then reinforced the rooth with a fiber post. At 4 years post op there appears to be complete radiographic clearing and retained radio-opacity from the calcium hydroxide.

Portal

Daily Fix

Amalgam is a great material because it’s not technique sensitive. When done well it stands up to quite a bit of abuse and hostility from the patient. Here we can see the whole distal dislodged. And while I can’t remember it ever happening to one of my buildups, I want to prevent it from happening. So I began, when reasonable making a portal that ties the distal component to the internal frustum core. A massive macromechanical retention feature. The result is this little triangle of tooth coronal to the circle in the second image. And yeah, I usually bond these big amalgams for belt suspenders as well as maybe some anti fracture attitude. The early portal cases naturally led to the double entry truss cases that followed.

Internal Approach

Daily Fix, Resorption

This tooth presented with inter-proximal external crestal resorption according to my resorption classification for clinicians. Usually I like to have an external surgical approach to ensure clean margins, manage the field, and work the appropriate matrix. However, an external approach here would have left one hell of a periodontal problem and lots of bone destruction. So, we worked it out internally. Ultimately, glass ionomer was used as the restorative choice here. On short termish recall, the perio tissues look great- 3mm probings all around and no bleeding on probing. So far so good, no resorptive recurrence.

Titanium Decision Making

Daily Fix

I’m not really even going to get into the decision making generally speaking with regard to the bridgework that cantilevers with two premolars off the back end of the canine, but doesn’t connect to the molar. But, I’m thinking that such a person used similar thinking with regard to their post choice. Radiographically this is either fiber or titanium. On access I confirmed titanium and then closed up shop and reappointed for the surgery. Unlike fiber, they can’t be drilled out, and unlike other metal posts they don’t vibrate out well, so the result of removal is coronal carnage. Thus the decision to whack.

Similar thinking led me down the road on this recall from a different patient this week. Bone fill at 6 months looks great with my eyes.

Lets leave the titanium to the implant specialists.

Root Form Appropriate Instrumentation

Daily Fix, Deep Fix

Contextualizing with history here is kinda important. As many of the old timers are calling it quits, it may be of benefit to put this down for the next generation of pulp slaying tooth fixers. The story goes like this. There was an observation that failing endodontics was associated with poorly root filled teeth. The following Schilder inference follows, namely: “Inadequate obturation of the root canal invites failure.” So the focus laser beamed on the fill and it’s associated process centered outcome. In order to employ the warm gutta percha technique, the root canal must be shaped so that a continuously tapering funnel is created with its narrowest diameter at the periodontal ligament and its widest diameter at the coronal opening or access cavity.

Back then they were doing this shaping by hand with reamers. And they had these stainless heat pluggers that looked like a spreader that they heated to a “cherry” red before “sheparding’ the gutta percha into the canals with graded stainless pluggers. So in order to get the pluggers to fit, they had to shape the canal to fit the graded pluggers. “Whala”, the continuous taper was unleashed and the rotary revolution followed suit. “Deep shape” became a thing and a lot of root dentin went down the drain. Observationally, we saw some of these break and wondered if maybe all that shape was necessary. Not to mention the strip perf’s. The first to make a change was Buchannan with GT files which at least had a maximum flute diameter. SSW under the direction of Khademi made the biggest leap a decade ago with variable taper instruments. That made things soooo much easier.

Out went shaping, deep shape and in came dentin conservation. Because, well, did you ever find anything that got stronger by whittling on it? Me neither. And yet we still had length control and root filling to contend with and accomplish. That led to the idea of rootform appropriate instrumentation. The balance of not hogging the tooth, and still accomplishing what was necessary. The apical taper kept the fillings from going long and the variable taper kept from too much coronal hogging. Using imaging and knowledge of root anatomy to guide the instrumentation was central to this approach. Using a thoughtful approach to balancing necessary and sufficient notions of root dentin removal achieve the desired process centered outcomes of the operator is the grounding principle behind root-form appropriate instrumentation., Generally speaking as long as the teeth were of average length and didn’t have extreme curves the following could be somewhat prescriptive as long as the prior principle is kept in the forefront of one’s mind and the driver doesn’t fall asleep at the wheel.

So prescription wise there are a number of great instruments out there. What I kinda landed on were three different instruments of different tips and tapers. Namely 17.04V (grey) , 20.06V (yellow), and 20.07V (blue) the V standing for variable taper as none of these are continuous taper instruments. The 17.04 and 20.06 I use are heat treated SSWhite instruments the 20.7 is the F1 by Tulsa which can be obtained in heat treated as well in their gold line. There are lots of F1 substitutes out there if your not a Tulsa fan. The colors here refer to the final file used. Longer roots than the average will typically mean dropping back a size.

This was all a decade ago, before tech. What’s necessary for tech? Probably less; hopefully less, maybe even none one day. There’s some evidence that the move to lose some weight from the continuous taper days has had some benefit in outcomes at longer time frames ie less breaking failures. Are there diminishing returns for losing additional weight, and whittling even less? Harder to tell. Maybe. Harder to root fill? Definitely. The instrumentation appears to approach some conservative silver point preps from the age before rubber or even smaller, considerably smaller with tech ended instrumentation.

The left image is presented with permission from a Shilder trained endodontist. The right was what I was trying to accomplish at the time highlighting root-form appropriate instrumentation as a pillar of Restoratively Driven Endodontics a decade ago. There are still tons of continuous taper rotary systems being employed today, pleasing the dopamine release centers of those enamored with “the look”. Countering those emotions are our own visceral response when we see extraction pending teeth that were given the deep shape death sentence.

Canine Dens

Daily Fix

Dens in dente are a relatively rare tooth deformity. Canine dens are particularly rare. The dens or “tooth within a tooth” presents problems in that the canal systems are highly irregular, challenging to disinfect, and difficult to fill. Often times surgery is necessary. In this case we were patient with the patient, used calcium hydroxide for a while and got a good result. Glad they aren’t all like this. Complete resolution in 3D with my eyes.

J- Shaped Retreatment

Daily Fix

This gentleman presented with pain and swelling as well as probing to the apex on the distal aspect of the tooth. Many people would say the tooth was cracked. But we’ve saved many, many teeth that fit this profile. J-shaped ragiographic findings are not pathognomatic for cracked roots. The the embrasure right with the tipping of the back tooth will be tough. Amalgam is a better choice when we are down on bone with potential contact issues in the future. Removing fiber posts if you have a chairside assistant in the scope is a breeze. The tooth had some reasonable buccal and lingual tooth structure so it makes it a decent retreatment candidate when following the Retreatment Algorithm.

Apically Perf’d

Daily Fix
Suffolk Endodontist

Seeing as how this case was both apically perf’d and had a large lesion, I would toss it into the problem case type bucket. But we gave it our best, and it looks like that was enough. I’m not sure I ever found the true path. Sometimes it’s worth taking a shot. Looks like things resolved completely in both 2D and 3D.

Soup to Nuts

Daily Fix

This patient was in for another tooth so we grabbed a followup of this case we performed 6.5 years ago. Pretty extensive distal caries under the crown. The wide platform lended itself to a truss access. Root-form appropriate instrumentation was completed. We used some bent ultrasonics for chamber cleanup and some bent pluggers to manage the amalgam utilizing a custom resin matrix. We can see the results of deep margin management over time.