Supraperiosteal Injections (Local Infiltration)

Supraperiosteal injection (commonly known as local infiltration) is indicated whenever dental procedures are confined to a localized area in either the maxilla or mandible. The terminal endings of the nerves innervating the region are anesthetized. The indications are pulpal anesthesia of all the maxillary teeth (permanent and primary), mandibular anterior teeth (primary and permanent) and mandibular primary molars when treatment is limited to one or two teeth. It also provides soft tissue anesthesia as a supplement to regional blocks. The contraindications are infection or acute inflammation in the injection area and in areas where dense bone covers the apices of the teeth, i.e., the permanent first molars in children. It is not recommended for large areas due to the need of multiple needle insertions and the necessity to administer larger total volumes of local anesthetic that may lead to toxicity.

Local Infiltration for Mandibular Molars

A number of studies have reported on the effectiveness of injecting local anesthetic solution in the mucobuccal fold between the roots of the primary mandibular molars. When comparing the effectiveness of mandibular infiltration to mandibular block anesthesia, it was generally agreed that the two techniques were equally effective for restorative procedures, but the mandibular block was more effective for pulpotomies and extractions than mandibular infiltration. The mandibular infiltration should be considered in situations where one wants to perform bilateral restorative procedures without anesthetizing the tongue. Bilateral anesthesia of the tongue is uncomfortable for both children and adults (Figure 9).

Technique:

• Retract the cheek so the tissue of the mucobuccal fold is taut.
• Apply topical anesthetic.
• Orient the needle bevel toward the bone.
• Penetrate the mucous membrane mesial to the primary molar to be anesthetized directing the needle to a position between the roots of the tooth. Slowly inject a small amount of anesthetic while advancing the needle to the desired position and injecting about a ½ cartridge of anesthetic.
• If lingual tissue anesthesia is necessary (rubber dam clamp placement), then one can inject anesthetic solution directly into the lingual tissue at the free gingival margin or one can insert the needle interproximally from the buccal and deposit anesthesia as the needle is advanced lingually.
• The needle is withdrawn and recapped.
• Wait 3-5 minutes before commencing treatment.

Figure 9. Infiltration of mandibular molars

Figure 9. Infiltration of mandibular molars

Local Infiltration for Mandibular Incisors

The indications for mandibular incisor infiltration are:

• To supplement an inferior alveolar block when total quadrant anesthesia is desired.

• Excavation of superficial caries of the mandibular incisors or extraction of partially exfoliating primary incisor (Figure 10).

If quadrant treatment is planned involving posterior and anterior teeth, mandibular infiltration is necessary to anesthetize the terminal ends of the inferior alveolar nerves that cross over the midline from the contralateral quadrant.

Figure 10. Infiltration for Mandibular Incisors

Figure 10. Infiltration for Mandibular Incisors