METHODS  OF  ADMINISTRATION Oral In dentistry, drugs are introduced into the body by different routes, each serving a specific purpose. We will cover parenteral, oral, inhalation, and topical administration of drugs next. Parenteral Parenteral medications are those introduced by injection. All drugs used by this route must be pure and sterile. Always check the solution to ensure it has not expired and is clear in color. Several types of parenteral administration can be used in dentistry. Intravenous—The  drug  is  introduced  directly into   the   vein.   Example:   Intravenous   sedation. Guidance   to   dental   treatment   facilities   for   the administration of outpatient anesthesia services in intravenous (IV) sedation to dental patients can be found in BUMEDINST 6710.67. Infiltration—This method that is commonly used to anesthetize maxillary teeth. The dental needle and anesthetic are placed into the mucosa along the side of the tooth (facial aspect) and alveolus that is being treated. This technique is possible because the porous composition  of  alveolus  cancellous  bone  allows  the anesthetic to soak through the bone and anesthetizes the apices of the teeth. It is also used in procedures such as biopsy, gingivectomy, frenectomy, and the excision of abnormal tissue. Block—Because  the  mandibular  bone  is  very dense, infiltration techniques cannot always be used to achieve adequate anesthesia. A block technique is the most effective means to achieve anesthesia of the mandibular teeth. A dentist will use various types of blocks  to  anesthetize  specific  areas.  When  performing  a block technique, the dentist will place the needle and anesthetic into the mucosa and aim them near a specific nerve where the solution is deposited. The area of the nerve is blocked and all surrounding areas the nerve branches   off   to   are   also   anesthetized.   When   a mandibular block (inferior alveolar nerve block) is performed, the patient will experience anesthesia on half of the mandible, including the teeth and lower lip. Periodontal   ligament   injection—If   this procedure is needed, it can be used instead of an infiltration  injection.  The  needle  and  anesthetic  are placed directly into the periodontal ligament along the side of the tooth, where the solution is deposited under pressure. This injection is very painful. Oral administration of medications comes in the form of tablets, capsules, liquids, and suspensions. Dental  patients  may  receive  medications  by  this method preoperatively (before) or postoperatively (after)  a  dental  procedure.  Another  route  closely associated with oral administration is SUBLINGUAL. The drug is placed under the tongue and is rapidly absorbed directly into the blood stream. An example is nitroglycerin sublingual tablets. Inhalation Inhalation  is  the  introduction  of  medication through the respiratory system in the form of a gas, vapor, spray, or powder. The three major types are vaporization,  nebulization,  and  gas  inhalation.  The most common type of gas inhalation used in dentistry is nitrous oxide sedation and will be discussed later in the chapter. Topical Topical agents are applied to a particular surface area of the skin being treated. Examples of topical agents  are  ointments,  creams,  lotions,  shampoos, paste, gels, and liquids. Dental topical agents will be discussed in this chapter under anesthetics. DRUG CLASSIFICATIONS The definition of a drug is any chemical substance that has an effect on living tissue but is not used for food. Drugs are used on or administered to humans or animals  as  an  aid  in  the  diagnosis,  treatment,  or prevention of disease or other abnormal conditions, for the relief of pain or suffering, or to control or improve any  physiological  or  pathological  condition.  A  drug may be classified in various categories, depending upon  different  criteria.  Examples  are  general, chemical, and therapeutic. General—Drugs are grouped according to their source,  whether  animal,  vegetable,  or  mineral  in composition. Chemical—Medications  are  grouped  by  their chemical  characteristics.  Examples  are  acids, bases, or salts. Therapeutic  (Pharmacological)—Drugs  are classified according to their action on the body. A drug may have more than one action. 7-2