Local & Regional Anesthesia in Pediatric General Dentistry.

Figure 55-1. Waving the syringe in front of the child before the administration of local anesthesia as a common mistake in dental practice.

There are two important aspects of administering painless anesthesia: ( 1 ) communication and (2) technical. The occurrence of fear and a negative experience of local anesthesia are most frequently found in children.^4,5

A calm and relaxed child is not only important for easier administration of anesthesia but also for its success, that is, the effect of the anesthetic.^5,10,11 Psychological and pharmacologic techniques can both be used to prepare the child for the administration of local anesthesia.

It should be stressed that a tense patient with an increased anticipation of pain usually feels more intense pain during local anesthesia. Acquainting the patient with surface (topical) anesthesia and the subsequent anticipation that there will be no pain, can reduce the anticipation of pain to a great extent. It is also important to stress that suggestion can be used, with the aim of reducing anticipation of pain. Suggestion and relaxation before the injection are also important for the effect of the local anesthesia.^5,11

Verbal communication with the patient is essential, and it should be maintained during the preparation and administration of local anesthesia. It is important to emphasize that surface anesthesia is given initially to ensure that all other procedures are painless and pleasant. The patient should be encouraged while administering the anesthesia. It should be stressed that this is done slowly so that the administration is more pleasant and the anesthesia is maximally effective.

Conversation with the patient achieves better relaxation before and during administration. If this is not possible by psychological means, sedation (eg, nitrous oxide or midazolam) can be used. However, sedation cannot replace local anesthesia; it is merely preparation for easier and more successful administration of the local anesthesia.¹¹

Injection Needle

The main reason for fear of local anesthesia for most patients is the needle. In the case of patients with strong fears or phobias of the needle, a needleless technique of local anesthesia can be applied (eg, jet injection).

During administration of needle injection anesthesia attention should be paid to ensure that the discomfort of needle insertion is minimal or completely prevented. Factors that influence the discomfort during the penetration of the needle include diameter (gauge) of the needle, type of needle, method of penetration through tissue, and quality of the topical anesthesia of the mucous membrane. For instance, a thinner needle causes less tissue trauma and less pain during penetration of the tissue (Figure 55-2). Needles thicker than 27 gauge (optimal 27 and 30 gauge) are not recommended for use in children.¹¹ Also, a slow injection of small amounts of anesthetic is less painful to patients. The site of the needle penetration should be prepared with the application some form of surface anesthesia.

Figure 55-2. Recommended sizes of the local anesthetic needles: A: Intraligamentar anesthesia: 30 gauge, 12 mm; B: Infiltration anesthesia: 27 gauge or 30 gauge; C: Mandibular block: 27 gauge, 25 mm.

Anesthetic

Two features of local anesthetic have an influence on pain during injection: temperature and pH. Prior to administering anesthesia, the local anesthetic should be at room temperature. If the anesthetic is kept in a refrigerator, it should be warmed up to body temperature prior to use by holding it in the hand or better yet, in a warming device^10,11 (Figure 55-3).

Local anesthetic that contains a vasoconstrictor (epinephrine) has an appreciably lower pH than plain solutions of local anesthetic. The lower the pH of the anesthetic, the more painful is the injection. Consequently, the use of local anesthetic without a vasoconstrictor is appropriate in children (eg, plain solutions of mepivacaine or prilo- caine). Indeed, studies have shown that pain associated with the intraoral administration of local anesthesia can be significantly reduced if a plain anesthetic without vasoconstrictor is used.^10,12

Figure 55-3. A device for warming up a refrigerated cartridge of local anesthetic prior to use.

Syringe

The level of anxiety in the patient before administration of local anesthesia also depends to a large extent on the appearance of the syringe. The traditional needle-injection assembly automatically induces fear of dental treatment in a child. To avoid fear of the needle or tension in the patient prior to anesthesia, it is possible to successfully use jet injection in some areas. This method then can be extended by additional administration of injection anesthesia, if necessary.