Dental local anesthesia and complications
1-The principle of local dental anesthesia
Technically, anesthesia is a transient and reversible suppression of sensitivity in a given area. The anesthetic blocks all nerve transmissions. The brain therefore does not feel pain. Anesthesia is called local if it affects the nerve endings. We will speak of regional anesthesia if the nerve trunk is desensitized.
The goal is to be able to operate on the patient without him feeling any pain. In the context of dental anesthesia, it is a question of numbing the apex of the tooth. This area is responsible for the sensitivity of the teeth. The dental apex is the opening of the pulp of the tooth up to the root. It is through this area that all nerve transmissions and blood vessels pass.
2-Indications for local dental anesthesia
- treatment of a cavity;
- tooth extraction;
- care on a dental root (root canal treatment);
- implant placement;
- bone graft.
3-Approach to local dental anesthesia
Periapical or para-apical, intrapulpal, loco-regional or osteocentral anesthesia: 4 possible methods of dental anesthesia.
*-Periapical or para-apical anesthesia
This anesthesia technique is generally used in the context of a tooth extraction . However, it does not work on molars. This method is painless for the patient. It allows one tooth to be numb at a time. Its scope is therefore relatively limited.
This anesthesia is done by injection at the gum level. The dental practitioner places the anesthetic product near the dental apices. The product diffuses towards the targeted area through the bone wall.
*-The intrapulpal method
This method of dental anesthesia is generally reserved for root canal treatment . It is the subject of heated debate among practitioners, because it is extremely painful for the patient. Some consider that it is preferable to resort to other anesthesia practices.
In practice, the specialist performs the injection directly into the pulp of the tooth . It can be used in addition to another dental anesthesia technique. Generally, the dental practitioner will use it as a last resort, due to the pain experienced by the patient.
*-Loco-regional anesthesia
This practice is used for molars on which periapical anesthesia does not work. It causes the mandibular nerve to be put to sleep in order to work on an entire part of the mouth. The effects are felt a few hours after the procedure. This dental anesthesia technique provides the opportunity to remove several wisdom teeth at the same time.
Local anesthetics are injected into the vicinity of a nerve or spinal cord. This helps numb the area the practitioner is going to work on. This type of anesthesia promotes rapid recovery and causes fewer side effects than general anesthesia.
Dental local anesthesia and complications
*-Osteocentral anesthesia
This practice is an innovation in the field of dentistry. It will have the same level of effectiveness as transcortical anesthesia, bypassing anatomical difficulties. However, osteocentral anesthesia cannot be used on all areas of the mouth.
In osteocentral anesthesia, the injection is made into the cancellous bone . This allows several teeth to be numbed at once, without numbing the soft tissues. This method does not cause problems with paralysis of the lip or mouth after surgery.
4-Adverse effects and complications
After dental anesthesia, care should generally be taken to avoid biting the cheek, lips or tongue; in fact, the lack of sensation means that the injuries caused are sometimes deep. The ideal is to avoid eating while the loss of sensation is still present (3 to 4 hours in general). Athletes should also be aware that some anesthetic products used for dental care can give a positive result in anti-doping tests.
A/ Local complications
*-Painful injection
The causes:
lack of experience of the practitioner
injection speed too fast
solution temperature too cold
poor choice of anesthetic technique
non-stretched mucosa
nerve damage
unsuitable needle type.
Dental local anesthesia and complications
*- Needle breakage
The causes:
manufacturing defect,
technical error by the practitioner,
sudden movement of the patient
*- Edema
The causes:
injection too fast
allergy.
*- Hematoma/Hemorrhage
The causes:
Vascular injury
*-Nerve damage
The causes:
direct nerve trauma (following truncal anesthesia),
following a hematoma or edema.
*- Lockjaw
The causes:
muscle trauma,
hematoma, muscle edema ,
infection.
*- Septic complication
The causes:
failure to comply with asepsis rules,
oral environment with many infectious foci.
*-Soft tissue injury
The causes:
Prolonged anesthesia → involuntary biting of the lips ; tongue (children and disabled people +++)
*- Complications related to the anesthetic solution (Gaping reflex, Dry socket,
Irritation or ischemia of the oral mucosa).
B/ Systemic complications
*- Vasovagal discomfort
It is a discomfort that can be attributable to excessive activity of the parasympathetic nervous system or to a decrease in activity of the sympathetic nervous system.
*- Anesthetic overdose
Causes: intravascular injection, amount of anesthetic administered (exceeding the
dosage), inflammatory state, patient’s terrain as in hepatic insufficiency.
*- Allergic reactions
Causes: allergenic molecules → anesthetic molecule (amino-esters +++),
preservatives, latex.
*- Anaphylactic shock
It is an exacerbated allergic reaction that can be life-threatening.
Dental local anesthesia and complications
Untreated cavities can reach the nerve of the tooth.
Porcelain veneers restore a bright smile.
Misaligned teeth can cause headaches.
Preventative dental care avoids costly treatments.
Baby teeth serve as a guide for permanent teeth.
Fluoride mouthwash strengthens tooth enamel.
An annual checkup helps monitor oral health.