Sensitivity elsewhere during a cavity preparation

 Often times when performing a cavity preparation, there will be sensitivity elsewhere in the mouth either due to exposed dentine or caries. This can make the procedure more difficult in patients with rampant caries, recession or generalised wear. Pain relief is important at this time so there are several strategies I use in these situations:

1. Use rubber dam, This will remove the problem entirely, sometimes if the situation is nfavourable, rubber dam may not be possible to use for the entire restoration, but at least short term use of the dam can help get the bulk of the prep out of the way comfortably.

2. Give local anaesthetic in the other areas. You can be hesitant to do this because that isn't the area you are working on but in the end, we give anaesthetic to block nerve conduction percieved as pain so the patient can get through the appointment comfortably. Therefore, if the patient is agreeable, local anaesthetic at the other painful sites can be very useful to achieve this. If there problem is widespread caries, if the other teeth are planned to restore, you could consider numbing all the areas, prepping all the teeth and covering all the areas with temporaries. Then you can come back another day to definitively restore the teeth with localised anaesthetic.

3. Apply flouride varnish to the sensitive areas: If the problem is with exposed dentine especially from toothbrush abrasion or active erosion, covering all exposed dentine areas with flouride varnish can provide instant relief to the air and water spray. I did this quite a lot in my first few years when I was treating quite a lot of these patients but rediscovered this trick just recently. 

4. Minimise the use of air and water spray: If the patient isn't that sensitive and the cavity is conducive, strategies such as using a spoon excavator instead of a handpiece and a slow speed suction/handpiece instead of a high speed can help to minimise the drop in temperature and flow of air that can trigger patient's pain. I don't like this idea as much because the first 3 options are simple, efficient and don't require much departure from normal practice. However, I can imagine a situation where a patient doesn't want a whole mouth of numbness, won't tolerate rubber dam and has large carious lesions which aren't helped with flouride varnish.