thanks for sharing your concern,
(LA) will temporarily interrupt conduction when absorbed into the nerve.
a blockade of afferent nerve transmission produces anesthesia
and lack of all sensations.
blockade of those fibers transmitting pain , sensation only results in regional analgesia.
the perception of heat cold and pressure are abolished by higher concentration of anesthetic agent then are required for interruption for pain.
the local anesthetic produces loss of function in following order, pain , temperature, proprioception
and skeletal muscle tone
the return sensation in the reverse order is expected.
some times patient under the effect of anesthesia traumatize their tongue cheek or lips for this reason longer acting agents may be contra indicated.
remember the local anesthetic solution are eventually absorbed in to the general circulation and can have toxic manifestation in overdosage.
yes repipititive usage of local anaesthesia have too many side effects like syncope,muscle trismus,haematoma,and adverse effects on CNS(central nervous system
),and CVS(Cardio vascular system.
therefore i would suggest, minimal usage of anaesthesia is best,if required post treatment analgesics could be prescribed.please donot be apprehensive about dental treatment.
if required you can take anti anxiety agents like alprazolam.
hope this helps.