Funny how ideas come in and out of fashion. This not only happens to individuals but also on a clinical level, like at a local dentist in Tunbridge Wells and on the institutional level. This has happened in sedation dentistry, as dental teams have moved away from cognitively impairing medications towards local numbing agents. Only to then find the calming effect of those early tools were very valuable and have had to re-adopt methods with a similar effect.
The early days
Pre-analgesics, distress and discomfort of treatment was one of the major elements of dental care. Well-off clients would be able to afford opium but poorer patients would drink heavily before a procedure.
The introduction of ether and nitrous oxide into clinics rendered patients unconscious during procedures. From a patient perspective this was ideal, but both ether and nitrous oxide suppress respiration during sedation leading to unnecessary fatalities. In the backlash, there was a big push to phase out sedation in dentistry, and the adoption of novocaine and lidocaine, which provided relief whilst retaining conscience.
Modern pharmaceuticals
With a better understanding of drug design and higher safety standards during the clinical trials, finding a safe sedation option in dentistry has been an active area of research. Leading to several drug options growing used in clinics.
Midazolam
This is a modern adapted benzodiazepine. It causes full sedation when used in high doses, and in low doses, suppresses the symptoms of anxiety whilst having minimal impact on respiratory depression or slowing the heart rate. This conveniently causes period or anterograde amnesia making it highly unlikely that the patient will remember any of the procedure. Its rapid onset of 15 minutes combined with its total half-life of three-and-a-half hours when administered intravenously makes it practical in dentistry.
Midazolam has not been proven safe in patients under the age of 3 or in the case of pregnant women.
Propofol
This has found itself as the most popular clinic option; it has a very quick on-set, a maximum of 8 minutes and a 7-hour half-life. It has been associated with falls in blood pressure during treatment and afterwards, making it inappropriate for patients who already have low blood pressure or are susceptible to fainting.
It also relaxes the throat tissues and can cause complications in patients suffering from apnoea or other ventilation complications like emphysema.
Ketamine
Ketamine has a long history of use in veterinary surgery; it is a disassociated analgesic in low dosages, allowing a patient to remain conscious and respond to requests whilst not experiencing any discomfort and having absolute memory loss. Patients can often enter into a rigid trance-like state. It has no impact on airway reflexes or cardio stability making it clinically very safe.
It is a central nervous system depressant and patients may experience depressive-like symptoms in the days following treatment; it can also complicate withdrawal regimes. It is not recommended for patients with psychiatric conditions or a history of substance abuse due to its association with relapse.
Ketamine is an excellent option for patients with complicated health conditions that could be aggravated by many traditional sedatives.