2. ISTHMUS FRACTURE
● Major cause is shallow preparation / inadequate depth of cavity.*
● Other reasons ー too wide cavity preparation, sharp ‘axiopulpal line angle’. So bevel this axiopulpal line angle
● If asked specifically about primary tooth isthmus # - shallow preparation
● If asked specifically about permanent tooth isthmus fracture – sharp axiopulpal line angle .

Q. The most common immediate ttt. Reported for fractured teeth was 25%.

3. AMALGAM BLUEING (TOOTH)
● Seepage of amalgam contents upto DEJ causing blue discolouration.
● Management ー prior application of varnish.

4. AMALGAM TATTOO (MUCOSA)
● Seepage of amalgam into the mucus membrane.
● Restoration, also retrograde amalgam restoration after apicoectomy.
● No treatment required.