Questions and Answers

Questions by 4122 Fourth year student 

Q1. How can I distinguish CLINICALLY between affected and infected dentin in deep excavations?

Answer:
 You have to observe the degree of discoloration (extrinsic stain)  and test the area for hardness by the feel of an explorer tine .
Sometimes the discoloration is slight and gradually changeable (in acute caries) and the hardness felt by the hand through an instrument may be an inexact guide, In this case  we can  use caries- staining products (a 1% acid red 52 solution for 10 seconds).

Q2. Should I remove all discolorations ?

Answer: 
In chronic (slow) caries , infected dentin  usually is discolored,and  the bacterial front is close to the discoloration front, therefore  all discolored dentin should be removed unless judged to be within 0.5mm of the pulp.

In acute(rapid) caries, the discoloration is slight, and the bacterial front is well behind the discoloration front, some discolored dentin may be left , although any remarkable discoloration should be removed.

procedure:

Start by removing the area of darker stain,and when working in the more lightly stained area ,use a spoon excavator to check for firmness: where it is firm ,protein matrix and tooth structure should not be removed,Hence all stains lighter than this should be left in place.


Art and science  of operative dentistry fifth edition chapter 9