294 Theories and techniques of oral implantology

dible, the anesthetic should be given at the level of the operative zone. The solution should be slightly warm and always injected slowly, with as few penetration points as possible.

Before injection, the operative site should be disinfected. Tincture of iodine, nitromersol, thimerosal, benzalkonium chloride, and benzethonium are all good mouth-sterilizing tinctures.

The operator must be extremely careful with anesthetics containing epinephrine, as vasodilatation can occur if the solution comes directly into contact with a blood vessel. Epinephrine also can cause a postoperative paresthesia or neuralgia if injected directly into a nerve. The addition of epinephrine to local anesthetics lessens the drug's diffusion and reduces bleeding.

General anesthesia

In general anesthesia there is a lack of consciousness as a result of partial brain paralysis. Because of the following disadvantages, general anesthesia should be contraindicated for implantation insertions wherever possible.

General anesthesia makes local conditions more difficult. It is difficult to keep the head motionless, and props must be used to keep the mouth open. These props limit the amount of room needed for the intricate instrumentation procedures used during an implant intervention.

A general anesthesia also increases bleeding and the flow of saliva (sialorrhea). A powerful suction machine must be used, taking up even more room and making it even more inconvenient for the implantologist. The tongue may become rigid and protrude, an endless cause for annoyance. For the sake of safety, a tracheal intubation by the nasal or oral passage is usually necessary.

Tips for general anesthesia. An implant intervention is generally much simpler if the patient is awake and responsive to the few requests that might be asked during implant insertion. If, however, general anesthesia is still desired, it should be administered under the auspices of a hospital, dental college, or clinic with an anesthesiologist present.

MEDICATIONS

The operator who performs implant interventions must assume responsibility not only for the success or failure of the implantation but also for his patient's health before and after the operation. This means he must have more than a general knowledge of drugs and be able to prescribe them in

telligently, in order to deal with any idiosyncrasy that might arise.

Antibiotics

Unless the patient has a history of predisposition to infections or of a condition that could be seriously intensified by an infection, preoperative or postoperative use of antibiotics is not necessary. However, if the operator routinely administers antibiotics with any surgical intervention, he will probably wish to do so after the implant intervention. It is imperative if using an antibiotic, however, to make sure the patient is not hypersensitive to it.

A good rule for deciding whether or not to ad-minister antibiotics concerns the number of implants and the age of the patient. Generally, the older the patient and the more the implants, the greater the advisability of antibiotic administration. Antibiotics given to completely edentulous patients after an implant intervention should be administered parenterally, instead of orally, to avoid gastrointestinal disturbances that might result with the soft, unfamiliar, postoperative diet.

Premedications

Although not necessary with a healthy patient, the effect of a local anesthetic could certainly be enhanced by the use of a carefully chosen premedication. This premedication will lessen the patient's fear, anxiety, and apprehension and prevent or re-duce accidents of vagus origin, sialorrhea, brachycardia, lipothymia, and nausea. It also could prevent such rare accidents as convulsions. Another advantage of a premedication is that it produces a post-operative analgesia after the local anesthetic wears away, a feature always appreciated by the patient.

As a general rule, light premedications can be prescribed to ambulatory patients, but strong pre-medications should be administered only to hospitalized patients.

General premedications. Dexamethasone phosphate sodium (Decadron Phosphate) is an adrenocortical hormone preparation that reduces postoperative swelling. It should be injected intramuscularly prior to a traumatic surgical procedure, such as a subperiosteal implantation. It can also be injected intravenously in the treatment of acute disorders responsive to adrenocortical hormone therapy, or locally in the treatment of intrasynovial (intraarticular and intrabursal) and soft tissue disorders. The injection solution is a clear, colorless