Anesthetic technique for inferior alveolar nerve block: a new approach

BACKGROUND: Effective pain control in Dentistry may be achieved by local anesthetic techniques. The success of the anesthetic technique in mandibular structures depends on the proximity of the needle tip to the mandibular foramen at the moment of anesthetic injection into the pterygomandibular region. Two techniques are available to reach the inferior alveolar nerve where it enters the mandibular canal, namely indirect and direct; these techniques differ in the number of movements required. Data demonstrate that the indirect technique is considered ineffective in 15 percent of cases and the direct technique in 13-29 percent of cases. OBJECTIVE: The aim of this study was to describe an alternative technique for inferior alveolar nerve block using several anatomical points for reference, simplifying the procedure and enabling greater success and a more rapid learning curve. MATERIAL AND METHODS: A total of 193 mandibles (146 with permanent dentition and 47 with primary dentition) from dry skulls were used to establish a relationship between the teeth and the mandibular foramen. By using two wires, the first passing through the mesiobuccal groove and middle point of the mesial slope of the distolingual cusp of the primary second molar or permanent first molar (right side), and the second following the oclusal plane (left side), a line can be achieved whose projection coincides with the left mandibular foramen. RESULTS: The obtained data showed correlation in 82.88 percent of cases using the permanent first molar, and in 93.62 percent of cases using the primary second molar. CONCLUSION: This method is potentially effective for inferior alveolar nerve block, especially in Pediatric Dentistry.

Evaluation of superficial microhardness in dental enamel with different eruptive ages

This study evaluated the superficial microhardness of enamel in teeth at different posteruptive ages (before eruption in the oral cavity, 2-3 years after eruption, 4-10 years after eruption and more than 10 years after eruption). The study sample was composed of 134 specimens of human enamel. One fragment of each tooth was obtained from the flattest central portion of the crown to produce specimens with 3 x 3 mm. The enamel blocks were minimally flattened out and polished in order to obtain a flat surface parallel to the base, which is fundamental for microhardness testing. Microhardness was measured with a microhardness tester and a Knoop diamond indenter, under a static load of 25 g applied for 5 seconds. Comparison between the superficial microhardness obtained for the different groups was performed by analysis of Student's t test. The results demonstrated that superficial microhardness values have a tendency to increase over the years, with statistically significant difference only between unerupted enamel and that with more than 10 years after eruption. According to the present conditions and methodology, it was concluded that there were differences between the superficial micro-hardness of specimens at different eruptive ages, revealing an increasing mineralization. However, this difference was significant only between unerupted specimens and those with more than 10 years after eruption.