Is it possible to just numb the tooth being worked on instead of whole side of mouth?

[credenza]

Is this something I can request my dentist to do? I have anxiety surrounding the numbing of my whole face and am looking to see if it’s possible to just numb a specific area for the most part. I am not worried about needles, just being numb.

 

[MattKW]

For upper teeth in general, the numbing is fairly localised because the injection is placed immediately adjacent to the bone and soaks through the relatively porous bone - an infiltration injection. Numbness of upper back teeth is the least annoying to patients, upper front teeth involving the lips is more annoying. Upper infiltrations are so reliable that we normally just get straight to work after a few minutes without checking the tooth numbness with a vitality test.
The bone around lower back teeth is usually too thick to allow penetration of the bone by direct infiltration, so a block injection is used which takes out the whole nerve to all lower teeth plus half the tongue and half the lip. This is the one that annoys most people. It has the added benefit that when your lip goes numb, we know that your teeth are numb.

• Infiltration of the upper teeth wears off faster than injections for lower teeth because there is a better blood supply in the upper jaw.
• The numbness to the teeth is is shorter than numbness to the soft tissues (cheek, lip, gums). For teeth most LA (combined with adrenaline) wears off in 60-90 mins, but the soft tissues may go 3-5 hours, and that works fine for most dental procedures from a dentist perspective. A shorter effect is obtained with LA that has no adrenaline but the operating time is lessened and not always good from a dental perspective.
• The adrenaline prolongs the numbness by restricting the blood vessels and thus the ability for the LA to be carried away. It also helps reduce bleeding if doing a bloody procedure like extractions. Surgical extractions with a plain LA is quite bloody.
• Some people claim that an articaine LA can be used as infiltration for lower back teeth - unfortunately it's not reliable, and if it doesn't work then you have to add a block which maybe should've been done anyway.
• For lower front teeth (incisors) you can try infiltration with relatively good success, or a lower mental block (premolars and incisors) which doesn't numb the tongue.
• There are other techniques like intraligamental - instant effect but short working time and more risk of bruising to local gums; intraosseous - instant effect but slow healing of injection site and higher risk of other complications. These techniques are generally better kept for supplemental LA usage where infiltration or blocks have not worked well enough, e.g. "hot" pulps.
• For upper front teeth some dentists and hygienists like to try a palatal AMSA because it can numb teeth and gums but not the lips. The downside is that it is best used without adrenaline so as to avoid possible tissue damage, but this will reduce working time.
• There is a reversal injection called Oraverse available that increases the local blood supply where adrenaline has been used. Some care must be used, but also consider that any painful procedure (deep fillings, extractions, deep scaling) will therefore wake up quicker, plus you will have extra tissue bruising from the added injection.
• Anecdotally, I have had a few patients who go to the gym after a simple filling and the exercise increases the blood flow and makes it wear off faster. Not after extractions!

So, no perfect answer.

 

[credenza]

For upper teeth in general, the numbing is fairly localised because the injection is placed immediately adjacent to the bone and soaks through the relatively porous bone - an infiltration injection. Numbness of upper back teeth is the least annoying to patients, upper front teeth involving the lips is more annoying. Upper infiltrations are so reliable that we normally just get straight to work after a few minutes without checking the tooth numbness with a vitality test.
The bone around lower back teeth is usually too thick to allow penetration of the bone by direct infiltration, so a block injection is used which takes out the whole nerve to all lower teeth plus half the tongue and half the lip. This is the one that annoys most people. It has the added benefit that when your lip goes numb, we know that your teeth are numb.

• Infiltration of the upper teeth wears off faster than injections for lower teeth because there is a better blood supply in the upper jaw.
• The numbness to the teeth is is shorter than numbness to the soft tissues (cheek, lip, gums). For teeth most LA (combined with adrenaline) wears off in 60-90 mins, but the soft tissues may go 3-5 hours, and that works fine for most dental procedures from a dentist perspective. A shorter effect is obtained with LA that has no adrenaline but the operating time is lessened and not always good from a dental perspective.
• The adrenaline prolongs the numbness by restricting the blood vessels and thus the ability for the LA to be carried away. It also helps reduce bleeding if doing a bloody procedure like extractions. Surgical extractions with a plain LA is quite bloody.
• Some people claim that an articaine LA can be used as infiltration for lower back teeth - unfortunately it's not reliable, and if it doesn't work then you have to add a block which maybe should've been done anyway.
• For lower front teeth (incisors) you can try infiltration with relatively good success, or a lower mental block (premolars and incisors) which doesn't numb the tongue.
• There are other techniques like intraligamental - instant effect but short working time and more risk of bruising to local gums; intraosseous - instant effect but slow healing of injection site and higher risk of other complications. These techniques are generally better kept for supplemental LA usage where infiltration or blocks have not worked well enough, e.g. "hot" pulps.
• For upper front teeth some dentists and hygienists like to try a palatal AMSA because it can numb teeth and gums but not the lips. The downside is that it is best used without adrenaline so as to avoid possible tissue damage, but this will reduce working time.
• There is a reversal injection called Oraverse available that increases the local blood supply where adrenaline has been used. Some care must be used, but also consider that any painful procedure (deep fillings, extractions, deep scaling) will therefore wake up quicker, plus you will have extra tissue bruising from the added injection.
• Anecdotally, I have had a few patients who go to the gym after a simple filling and the exercise increases the blood flow and makes it wear off faster. Not after extractions!

So, no perfect answer.

Wow. Thank you SO much for such a thorough answer. I've considered the Oraverse route, as well as the LA without adrenaline. You say a LA for teeth wears off in about 60-90 minutes but lasts 3-5 hours on the soft tissues - what about LA without adrenaline? How long do teeth and soft tissue stay numb then?

Thank you!

 

[MattKW]

I've never heard of any colleagues using Oraverse (phentolamine mesylate) so it might be hard to find.
Sorry, LA without adrenaline only seems to reduce the length of tooth numbness, not the tissue numbness. Prob due to different nerve fibres for pain versus pressure.
Maybe it'd just be easier to go for a brisk walk afterwards!