Differentiate Composite from Tooth?

[BigSmiles]

I had a 'test case' today that I totally bombed because I had to go into a mesial Class III on 7 to take care of some recurrent caries. I thought I had gotten all the composite but the teacher disagreed. She told me to take an explorer and go over the tooth and the composite will 'make a white line'(?)...which I COULD NOT SEE....is there a sure way of telling where the composite ends and tooth starts?

 

[cmcner]

Drying the tooth off makes it easier to see composite. If that doesn't work etching is a good way to double check because composite won't etch.

 

[BigSmiles]

The tooth was pretty bone dry, I still couldnt tell. I had on loupes w/ the light....There's gotta be a better way....I have several test cases coming up w/ removal of composite so it's pretty essential I learn a sure shot way....

 

[lemoncurry]

i've replaced a number of class III comps in my limited experience thus far, and the only sure fire method that works for me is using a slow speed round bur. if it cuts, it is either decay or composite (unless you're laying on it heavy). if you've gone over the whole prep with the round bur, you can feel the difference btwn tooth and comp with your explorer. my experience is that if something feels off, it probably is. I replaced a class II comp recently and was finishing up my box prep when i got the feeling that the tooth structure on the gingival floor seemed too smooth and evenly shaded. turns out there was a layer of comp still there.

 

[Streetwolf]

It will come with experience. For a while I had trouble with it but now I'm really starting to figure out composite vs tooth. It's just something I have to see.

Are you using a real tooth or typodont? Could be harder on typodont if the shade of composite is a good match.

 

[The Hammer]

If you dry composite you can scratch it with a sharp explorer and it will leave a mark (a dark line). Enamel and dentin won't mark like that

 

[HupHolland]

+1 for the etch check. Although you would never do this in the real world, I would definitely recommend it for competencies and board exams.

Hup

 

[BigSmiles]

Streetwolf- I was working on a pt, not a typodont....
Thanks for the tips guys...I will def try the 'etch check' next time....meanwhile....I guess I will slowly learn the tactile differentiation part with more experience....