Removing decay qs?

[sddat]

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This is a weird question, but I'm having trouble removing decay on pts with caries. I never feel like I know how far to go before I will hit the pulp. I'm always worried about going too far. Does anyone have any tips for removing caries on pts? This is something that was not simulated in my preclinical experience.

Thank you

 

[DrJeff]

This is a weird question, but I'm having trouble removing decay on pts with caries. I never feel like I know how far to go before I will hit the pulp. I'm always worried about going too far. Does anyone have any tips for removing caries on pts? This is something that was not simulated in my preclinical experience.

Thank you

It's pretty simple actually. The decay goes where the decay goes. The pulp is where the pulp is. You can't change either of those factors.

Personally after working on teeth for almost 20 years, I still go by the basic cavity preparation principles as outlined by G.V. Black the vast majority of the time.

And that's start with the overall outline form of your cavity preparation and make it as ideal as possible (i.e. breaking interproximal and gingival contacts for a class II prep, extension into the grooves for a class I/II prep, dove tail and cavo-surface margin bevel for a class III prep, etc). Once you have that classical, "ideal" outline form, then target the decay - the majority of the time it's just as simple as following that typically brown colored dentin initially, and then when you have uniformed colored dentin it time to get either your explorer or spoon excavator out and make sure that the dentin is all uniformly hard. If you've got unformly colored and firm dentin inside your prep, then chances are that you've removed all the decay. If in doing this, the pulp is exposed, well then it's exposed, that's just restorative dentistry.

Initially as you're removing decay once the classical outline form has been established, just go slow either with a spoon excavator or a slow speed round bur. After your comfort level goes up and/or you reach private practive, you tend to do the vast majority of your outline form and caries removal seemlessly, all with your high speed hand piece and your bur of choice at that moment. Initially though, go slow and really learn what carious dentin both looks and feels like, since there is no real subsitute for clinical experience. Initially some caries indicating solution might help, after a while you'll see that you can do just as good a job, visually and tactily without the indicator solution and having to deal with cleaning it up after! 😀

 

[djeffreyt]

I'll start with the assumption you are just starting clinic in school. If you are removing decay for a filling, and this is a wild generalization, chances are you won't hit the pulp. If the decay was big enough that it would hit the pulp, I would hope your instructors would have caught that and determined the need for RCT or crown treatments. 99% of the teeth we try to fill should not reach the pulp or even come close.

Most beginning students are very cautious when it comes to removing decay, so this is a normal question. Best ways to determine decay clinically are to prep until you reach dentin...it's yellow, it should be easy to tell. Then use your explorer. Is it sticky and soft? Then it's decay, cut further. Depending on how sticky and soft and how far your explorer goes, that will determine if you cut half a mm or 2 mm further. If you touch the tooth and it's hard, great, chances are you've got all the decay. If you want to be more cautious, air dry the tooth and then scratch the hard surface with the explorer, if it's chalky and the explorer leaves little white scratch marks, you probably have a tiny bit more to remove. No marks or silvery lines, no problem. stop cutting. Teeth can have stain without decay, just cause you see a brown line in dentin, doesn't mean you need to cut it out if it's hard as nails. When you do class 2 preps, make sure you break all the interproximal contacts. Once you've done that, you can check visually. If the margins of your box look chalky white or stained, I'd enlarge your box margins in that area, but otherwise if it's hard the the radiograph showed the decay just below the contact area, then I wouldn't cut further.

Another option is to use a spoon excavator. With light pressure, a spoon should not remove healthy dentin, but it will cut out unhealthy dentin. Another option if you are being cautious is to use a slow speed with light pressure. Want to be even more cautious, put the slow speed in reverse. A slow speed in reverse without a lot of force will remove any decayed and soft dentin easily but will not cut easily into hard and sound dentin. Not to say if you don't push hard enough you can't cause it to cut into dentin, but without a lot of force and the flutes of the bur running in reverse, it's not gonna cut sound dentin easily.

Lastly, if you are doing an occlusal, the average pulp is probably 5-7 mm from the occlusal surfance, so if you are 2 mm into a tooth and debating if you'll hit the pulp in the next mm, you probably won't.

Use your radiographs as a guide, they will tell you a lot about how much room you have for errors.

 

[sddat]

Thank you both DrJeff and Djeffreyt

Yes I'm brand new to clinic..both of your posts are extremely helpful.

I have spent so much time in preclinic, that I don't really know what to do in real clinical situations. Both of your post are similar in that you start your prep and then find the decay. So should I always make that perfect class I prep at first, and if so how far should my initial bur depth be?

For example, if I have a class 1 lesion, would you sink a 330 bur about 1.5 mm and do a typical class I prep (extending to the secondary grooves) all the while looking for the decay or is that too much extension? My biggest problem is, I don't know where to start.

My professors say to follow the caries, but I think that can be interpreted in different ways.
Thank you again

 

[DrJeff]

Thank you both DrJeff and Djeffreyt

Yes I'm brand new to clinic..both of your posts are extremely helpful.

I have spent so much time in preclinic, that I don't really know what to do in real clinical situations. Both of your post are similar in that you start your prep and then find the decay. So should I always make that perfect class I prep at first, and if so how far should my initial bur depth be?

For example, if I have a class 1 lesion, would you sink a 330 bur about 1.5 mm and do a typical class I prep (extending to the secondary grooves) all the while looking for the decay or is that too much extension? My biggest problem is, I don't know where to start.

My professors say to follow the caries, but I think that can be interpreted in different ways.
Thank you again

Personally as I'm about to start prepping a tooth, removing decay, and restoring it, I very often think about what IDEALLY I want the final restoration to look like, and then base my preparation around that IDEAL shape that I want to enable me to restore that tooth to the best of my ability - *Most* of the time the vast majority, if not all the decay will be removed in the process of making that ideal prep. Sometimes, based on where the decay goes my final prep will look far from ideal 😱 , but then again that's just restorative dentistry days 😉

So in that hypothetical class I that you mentioned, yup, I'm going to go in initally and make my prep to that "ideal" 1.5-2mm depth. The only variance may is that as I'm starting my prep, I'm going to begin in the groove(s) where I see the decay clinically, and if in prepping the tooth, I clinically see that a different groove is caries free (and I'm 99.9% sure of it), then I'll very often leave that "virgin" enamel and dentin alone and just restore the caries affected area. After my initial ideal prep, then I'll assess if there still is caries present and what direct it appears to be heading, and then remove all the caries. After all the caries has been removed, then I reassess what that inital "ideal" prep looks like now (afterall there are sometimes when to remove all the caries, you will have to alter the shape of your initial ideal prep) and then if needed make appropriate modifications to the shape of the inital prep to remove any unsupported enamel and make sure that my the prep that i'm about to restore will have appropriate resistance and retention forms - and there are sometimes when after decay removal, I'm going to end up having the conversation with my patient where I tell that that based on where THEIR decay was in THEIR tooth, that ideally THEIR tooth should be restored not with direct filling material but with a crown/inlay/onlay.

Right now,e arly in your career, if it seems like there's about 1001 things to think about, yup that probably about right! After some experience, it WILL become a seemless thought process for you!

 

[Kam1]

You could use 'caries indicator,' it's a dye that'll stain the decay.

Good luck...

 

[djeffreyt]

Thank you both DrJeff and Djeffreyt

Yes I'm brand new to clinic..both of your posts are extremely helpful.

I have spent so much time in preclinic, that I don't really know what to do in real clinical situations. Both of your post are similar in that you start your prep and then find the decay. So should I always make that perfect class I prep at first, and if so how far should my initial bur depth be?

For example, if I have a class 1 lesion, would you sink a 330 bur about 1.5 mm and do a typical class I prep (extending to the secondary grooves) all the while looking for the decay or is that too much extension? My biggest problem is, I don't know where to start.

My professors say to follow the caries, but I think that can be interpreted in different ways.
Thank you again

I agree with Dr. Jeff. Ideal prep form first, but just a quick preparation of ideal. Don't sit there spending all this time making every exit angle perfect and all the depths perfect. Chances are you will extend some and cut more, so why prerfect a shape that will change momentarily, just make a good shot at ideal. Check for the need to prep more for decay removal, and do it....then finish and refine the prep as Dr. Jeff mentioned.

A lot of preparation shape and extension is patient dependent. I work on a fairly low income and low socio-economic patient pool. While I definitely have a range, the majority of my patients do not have the best home care. While a secondary groove may not have caries, sometimes removing it because the patient has a very high caries rate in grooves in general, is a good idea. If I had a 40 year old woman with a dental history of 2 fillings, regular cleanings, low plaque score and a single occlusal stick on #30 on the mesial pit and stained but non-cavitated areas on other teeth including #30, I'd just fill the mesial pit and leave the rest of the tooth in virgin form. That same mesial pit stick on a patient with 8 other pit and fissure caries and heavy plaque gets a much mroe aggressive filling on #30.

Good luck.

 

[HupHolland]

^ what he said.

Use a 245 or 556 instead of the 330 you were used to in preclinic. "Ideal" prep doesn't matter anymore. Assess your patients caries risk and combine that with your clinical + radiographic findings. Prep ideal with the intentions of extending your prep based on sticky dentin. Rock solid dentin need not be removed - even if it's discolored.. If unsure, take a round bur in your slow speed and cut. If its coming out chunky, it's caries. If it's chalky, leave it alone.

There have been instances where I have left a minimal amount of caries adjacent to pulpal wall, as removing it would result in a pulpal exposure. I place a glass ionomer (vitrebond, fugi liner, etc.) and restore. Let the patient know temp sensitivity is normal, ache/throb is abnormal and may need a root canal. More ofthen than not, pt will be asymptomatic. In cases they do become symptomatic, you gave them a heads up.

Hope that helps,
Hup