It has been generally accepted that mandibular molars are the most difficult teeth to anaesthetise, especially if irreversible
Molars are large, flat teeth located at the back of your mouth. They are primarily used for grinding and crushing food. Molar root canals are usually more difficult than incisors because they have more roots and require specialized instruments to access them.
In our list above, it's the “inferior alveolar nerve block” (mandibular block) that's singled out as the most painful of the routine injections used to numb up teeth. van Wijk performed a study to determine exactly how much pain is felt when one of these injections is given. It evaluated 230 oral surgery patients.
The techniques most commonly used in maxillary anesthesia include supraperiosteal (local) infiltration, periodontal ligament (intraligamentary) injection, PSA nerve block, MSA nerve block, anterior superior alveolar nerve block, greater palatine nerve block, nasopalatine nerve block, local infiltration of the palate, ...
With the reduction of infection in the area, inflammation also begins to slowly subside. This allows your dentist to fully numb the hot tooth in question, and perform the procedure without putting you through the anguish of dental pain.
If you have a particularly painful tooth and it won't get numb, your dentist might refer to it as a “hot tooth.” When a tooth causes significant pain, it can change the nerves which can make them overactive. If it's overactive, it will require more anesthetic than usual to calm it down.
A serious dental infection can “neutralize” the effects of local anesthetics making it very difficult to numb the patient for treatment. Infected lower molars are especially difficult to numb in the presence of a serious infection.
The superior alveolar nerves, anterior, and posterior, form a loop within the maxilla. From this loop dental and gingival branches arise that supply the upper teeth, and the upper gums. The maxillary nerve also gives off palatine and nasopalatine branches that supply the palate, and parts of the nasal cavity.
A maxillary nerve block is administered to nerves near the upper bone plate of the jaw to numb the face. A maxillary nerve block is a procedure that provides regional anesthesia to parts of the nose, upper jaw, cheek, and mouth.
The mental nerve block provides anesthesia only to the lower lip and soft tissue of the chin. It does not anesthetize the teeth, which would require an inferior alveolar nerve block. If the foramen is not directly palpable, the anesthetic can be injected into the buccal mucosa between the 2 lower premolar teeth.
Nerve damage after a dental injection
This nerve damage could be minor, and the symptoms may disappear on their own after a few days or weeks. Alternatively, the nerve could potentially be damaged more seriously, which may mean long-term or even permanent symptoms.
Root canals are a painful surgical procedure involving cleaning the insides of the root canal in your tooth, irritating the surrounding nerves and gums. Root canal treatment is an endodontic procedure to eradicate infections within your tooth.
Most local anesthetic is more acidic than our body's natural pH level, which is very close to neutral. Because of this, we feel a burning sensation as it is injected. This burning sensation is registered as pain.
Root Canals Aren't Possible with Severe Infection
If the deepest layers of the pulp become infected, it may be too late to save the tooth. In addition, if a large portion of the tooth is lost and a crown cannot be placed on what's left, root canal treatment is no longer a viable solution.
The canines have a single long root and a single root canal. The canine roots are the longest root of all teeth. Furthermore, the upper canines have longer roots when compared to the mandibular canines. The canines serve to support the incisors.
Understanding Root Canals
For example, molars take the longest and they may take as long as 90 minutes because they have four roots. On the other hand, canines and incisors only have one root and take only 45 minutes to treat.
You may not be eligible for one if you have an infection at the site where the injection would be made, if you have a bleeding disorder, if you are taking an anticoagulant (a drug such as warfarin that prevents blood clots) that you have not stopped ahead of time, or if you have had problems with the nerve in the area ...
The posterior superior alveolar (PSA) injection will anesthetize the maxillary molars except for the mesiobuccal aspect of the first molar (Figure 1). The periodontal ligament (PDL), bone, periosteum, and buccal soft tissue adjacent to these teeth are also anesthetized.
The inferior alveolar nerve block, a common procedure in dentistry, involves the insertion of a needle near the mandibular foramen in order to deposit a solution of local anesthetic near to the nerve before it enters the foramen, a region where the inferior alveolar vein and artery are also present.
Anterior superior alveolar nerve block
The anterior superior alveolar (ASA) nerve block anesthetizes the maxillary canine, the central and lateral incisors, and the mucosa above these teeth, with occasional crossover to the contralateral maxillary incisors (see image below).
As a branch of the trigeminal nerve, the maxillary nerve is often implicated in trigeminal neuralgia, a rare condition characterized by severe pain in the face and jaw. 1 In addition, lesions of this nerve can cause intense hot and cold sensations in the teeth.
It runs inferior and lateral to the ophthalmic nerve. It then leaves the middle cranial fossa through foramen rotundum and enters the superior part of the pterygopalatine fossa.
In case of inflammation where there is acidic pH (5–6), the amount of free base liberated from the tissues is less thereby minimal local anesthetic molecules penetrate into the nerve membrane. This is the reason for local anesthetics do not work efficiently in infected and inflamed pulp and periapical tissues [1, 3].
An X-ray of the aching tooth can help identify an abscess. Your dentist may also use X-rays to determine whether the infection has spread, causing abscesses in other areas.
When the nerve is severely inflamed by bacterial from deep cavities, a root canal removes the living portion of the tooth and does kill the nerve. This is only done when the tooth nerve is beyond healing and cannot repair itself. Severe pain and sensitivity to cold and hot can be indications the tooth cannot heal.