Teeth And Anesthesia
Pain is the most common manifestation of dental disease and as such the advent of anesthesia may be regarded as a cornerstone in the development of modern dentistry. Historically, dental pain or a toothache is regarded as the worst thing experienced by man since times immemorial. Despite the development of modern equipment and technical expertise, if there is one thing that dentists have been unable to control, it is the pain that presents itself in a variety of ways. In fact the nerve in the tooth or the pulp as it is called has fibers that can transmit only pain as a response to any stimulus. These fibers are unique to the body in this regard. A visit to a dentist is the scariest experience for some people, while others are able to sail through it relatively unscathed. It is here that anesthetic agents have served as a blessing to dentists and patients alike.
History Of The Development Of Dental Anesthesia
The history of dentistry is somewhat chequred and is littered with unimaginable anecdotes. For example,
the whole process of pulling out a tooth before anesthesia was known makes for interesting reading. The patient or in this case the victim was lead to an open field and a thread was tied around the offending tooth. Two burly lads held the patient down while the thread was pulled by a horse galloping at full speed! Later on barber dentists arrived and the process of getting a tooth pulled became more civilized. It must be pointed out though that anesthesia is used not only for extraction of teeth, but also for procedures that cause pain such as drilling cavities or cleaning the teeth deep into the gums.
The modern anesthetics owe a lot to cocaine, which was the first natural anesthetic to be used. Although, it is no longer used in dentistry, it is worth noting that the loss of sensation caused by it was quite adequate. For that matter most of the drugs used today in dentistry are synthetic in nature. They belong to two groups, namely, Ester or Anilide group.
* Lidocaine (most commonly used)
Most of these agents produce adequate loss of sensation, but some of them have more adverse reactions than the others and are hence not in common use. Lidocaine happens to be the most commonly used anesthetic agent in dentistry today.
A typical anesthetic solution contains lidocaine, adrenaline, methyl paraben, sodium meta-bisulphate, sodium chloride and water to make the solution. Adrenaline is a vasoconstrictor, meaning that it constricts the vessels, thereby prolonging the action of the anesthetic. The other chemicals are reducing agents to lidocaine hydrochloride and adrenaline.
Basically, anesthetic solutions in dentistry are administered in two routes,
*Intra-oral, meaning into the mouth and
*Extra-oral, meaning outside the mouth on certain areas on the face.
The intraoral route is by far the commonly used route of anesthetic administration in dentistry. Again, depending on the procedure to be performed, the areas of administration vary. If a single and very mobile tooth is to be pulled out, then the area around the tooth is singularly anesthetized. Where as multiple extractions or complex surgical procedures require one side of the face to be anesthetized. This is done by injecting the solution close to the nerve, which supplies these areas of the mouth. The effects of the anesthesia last from 2-4 hours though it can either last longer or shorter depending on the concentration of the anesthetic agent.
Contraindications and complications
As such there is no absolute contraindication to the administration of anesthetic agents. There however exist some conditions where it is not advisable to give the full concentration of the drug. High blood pressure or hypertension is one such condition where adrenaline is not included in the anesthetic solution. All the other components are the same. Another condition is allergy to the solution. If the allergy is acute then local anesthetics are abandoned and general anesthetics are chosen. Complications of dental anesthesia mainly have to do with the inadvertent injection into a blood vessel. In such a case, a hematoma develops with subsequent swelling and pain. This however is treatable and goes away in no time.
Latest activity in the field
Jet injectors have been developed so that even the pain of the needle prick is not felt. Since the
administration of the injection is basically a blind process in that dentists actually do not know if the needle has gone into a vessel, efforts to incorporate a microchip connected to a monitor are being pursued. This will allow dentists to actually see where their needle has gone and could cut down the risk of injecting into a blood vessel.