Avoiding Procedure Redo Due to Contamination: Class II Caries

By Back Lexi Marino June 4, 2021

Procedure redo’s are a dentist’s worst nightmare. That’s why we interviewed Dr. Tom Hirsch, DDS to see how he avoids contamination in a Class II caries case.

Watch this video to learn how to achieve better clinical outcomes in 3 ways:

  • Keep the patient’s tongue permanently retracted
  • Continually remove excess blood and saliva
  • Achieve a well-lit field to confidently find all decay that needs to be removed


Rolando Mia: Good morning everybody. Welcome, welcome to Dental Voice, “On the Case”. In this series, various clinicians are sharing with us how they overcome challenges during their dental procedures. Today, Dr. Tom Hirsch is going to share with us how he achieves a better clinical outcome by eliminating contamination in a Class II Caries procedure.

The Case: Class II Caries

Dr. Tom Hirsch, DDS: So today, we’re going to talk about Class II restorations and how to prevent contamination.

I was doing two Class II back-to-back restorations. One was an MO on tooth number four, and the other was a DO on tooth number five. What we’re trying to do here, contrary to the GV black cavity preparations that we were taught in school, is we’re just trying to do minimally invasive dentistry right now. So, I’m trying to get the interproximal decay out. Which we had a little spot right there a little mesial aspect.

We can see here that there’s a lot of ways to reduce contamination. One of the ways we’re taught in school is the rubber dam, which I think is just fabulous. Any time that I’m going in and I’m doing a class two restoration where it is subgingival at all. I’m going to go ahead and use a rubber dam. I can wedge the contact area.

Keeping the Tongue Away from the Working Area

However, in this particular case, we didn’t need to do that. Isolite®’s isolation is another really good way to do it. So, what we’re doing right now is we’re just removing all of the decay. One of the issues that people come up when we’re working in areas like this for contamination is keeping the tongue out of the way. I’ve got all the decay cleaned out and going and I’m etching the teeth and we need to keep that tongue out of the way. Contamination can come from blood, from saliva, from not getting the preparation cleaned.

With, the Isolite in this instance, is we’re getting the tongue out of the way. I don’t have any bleeding; I don’t have any moisture contamination. Which you can see here. We’ve got those preps cleaned, dry and isolated. Little bit of bleeding going on there. So, we’re going to want to control that hemorrhage on that.

We’re putting on a circular matrix. I’m putting both these on back-to-back. Sometimes when we do this, the Isolite might get in your way. If you don’t have enough room when you’re doing this, what I do is I’ll take the Isolite out for a second, put the matrix bands around the teeth, and then go ahead and put the Isolite back in so that they don’t have any contamination.

Keep Minimal Amount of Hands Working in the Mouth

So now we’ve gone ahead, we bonded these restorations. Putting a little flowable down to the gingival aspect. This way, we get a seal down there at the bottom. Then what I’m going to do is just pack these things up gently. Really make sure we don’t have any air bubbles in there. And just get it done.

The nice thing about this is I don’t have the tongue in my way and my assistant can really be there just to help me. Now I don’t fill these back-to-back because, with two matrix bands in there, we’re going to have a space issue. Make sure that we still have a good gingival seal. We’ll put a little Garrison ring on there for separation on that mesial.

We’re going to go ahead and fill the mesial first. Oh, check that out in the back. I didn’t even notice that when I took the matrix ring way in the back, the extra part of the matrix retainer is just sitting in the back. I didn’t even notice that until just now. One of the things we’d have to worry about is that going down somebody’s throat with the Isolite in the mouth. So, we get in there, we just fill these things right up. Whether we’ve used the rubber dam or whether we use the Isolite. We just have great contamination control. Yep, I use cotton rolls too.

Permanent Isolation Reduces the Risk of Contamination

Rolando Mia: Dr. Tom I noticed that during the treatment, your patient doesn’t seem to be compromised at all. She looks really comfortable.

Dr. Tom Hirsch: Yeah, she’s just relaxed. She’s just sitting there just nice and relaxed. This took about 20 minutes. Not bad start to finish.

Rolando Mia: During the course of this video, you mentioned the Isolite sometimes gets in the way. Does that often happen or no?

Dr. Tom Hirsch: Sometimes, when it’s in the way I’ll take it out and I’ll put it right back in. For instance, if I had to have my handpiece coming here from the lingual and there wasn’t enough room with the finishing of the end. I just take it out and do that finishing at the very end. It’s going to come out anyway and we don’t have to worry at the end of the procedure for any contamination. You know, the filling is done, it’s in place, it’s bonded well.

The thing that we don’t want is to have contamination during procedures. Because if we get any contamination we’re going to have to go back in and have to redo that at some point in time in the future. We don’t like to redo our work, we want to be done with it.

Rolando Mia: Yeah, and I noticed too… Class II’s are common would you say?

Dr. Tom Hirsch: Most of our work involves the interproximal surfaces in the teeth.

Rolando Mia: And when or if they become contaminated typically what happens? How does that restoration fail?

Better Clinical Outcomes

Dr. Tom Hirsch: In a week, you know, if they get contaminated, we all know we get marginal leakage, bacteria gets in there and get staining of the margins, and it’s going to re-decay. We have to avoid that at all costs.

Rolando Mia: Yeah. I just recently had several of my amalgams taken out and with the Isolite, it’s incredible. I like the fact that you’re able to keep that tongue cheek out of the way, even use the cotton rolls in there to give you an additional kind of a spacer or keep all that contamination out. Your outcomes are phenomenal because everything is completely clean.

Fantastic! Thank you so much, Dr. Hirsch. Have a great day everyone. We look forward to seeing you. If you like this, please share. If you have any questions, let us know. We look forward to seeing you again on Dental Voice “On the Case”. Appreciate it.

Dr. Tom Hirsch: See you guys later. Bye.