1996 Fiscal Year Final Research Report Summary
On the morphological changes of local dental anesthetic injection with 2% Lidocaine to the bundle of the inferior alveolar nerve and artery.
Grant-in-Aid for Scientific Research (C)
|Allocation Type||Single-year Grants |
|Research Institution||Meikai University |
FUJITA Kuniya Meikai University School of Dentistry, Professor, 歯学部, 教授 (90028746)
SIGEMATSU Hisao School of Dentistry, Meikai University, Assistant, 歯学部, 助手 (70187350)
SAITO Kazuhiko School of Dentistry, Meikai University, Assistant, 歯学部, 助手 (30153795)
SIGEMATSU Yoshiaki School of Dentistry, Meikai University, Assistant, 歯学部, 助手 (90162594)
SUZUKI Seiji School of Dentistry, Meikai University, Assistant Professor, 歯学部, 助教授 (40129119)
|Project Period (FY)
1995 – 1996
|Keywords||rat inferior alveolar nerve / rat inferior alveolar artery / infiltrative injection. / histopathological changes / mandibular nerve block anesthesia|
In a surgical procedures in any speciality of dentistry there is an inherent risk of damage to peripheral nerves and/or arteries. This has resulted in continuous reserch of local anesthesia in the field of dentistry, aiming at safer drugs and better techniques. Local complications of dental anesthesia depend on the trauma caused by the needle and injection and/or the local toxicity of the anest hetic drugs, concern primarily the nerve, but also neighboring structures. This study evaluated the results of the local infiltrative anesthesia of clinical training of students (1541 students-M : 1217, F : 324). The most frequent complication was postinjection trismus (10.4%), but paresthesia of nerve was 4 cases (1 : inferior alveolar nerve, 2 : lingual nerve, 1 : transient facial nerve paralysis). Blood-aspirations were demonstrated in 4.4% (112/2573) of the cases. These complications associated with inferior alveolar nerve block were generally tempolar and the symptoms were mild.
studies were conducted to investigate histopathologically the effects on the rat inferior alveolar nerve and artery in the mandibular canal of infiltrative injection of 0.027ml of 2% HCI-lidocaine with (LE) or without (L) 1/80000 epinephrine directly into the bundle delivered by a constant low-speed (0.009ml/sec) motor-injector with 30G short-beveled needle. As for the severity of damage of injection, the LE groups showed earlier onset of the damage and longer duration with respect to than the L groups.
With respect to the difference in the damage caused by the number of insersions of the needle, more insertions (L 10, LE 10) resulted in greater damage than a single insertion (L 1, LE 1) (in both L and LE groups). The groups that received epine phrine (LE 1, LE 10) showed greater damage than those that did not receive it. The damage observed degeneration or destruction and disappearance of myelinated fibers. The initial changes in the nerve involved interruption, granulation and disappearance of myelin in areas of stronger damage.
The change in the artery appeared initially as a contraction accompanied by thinning of the adventitia ; after there, the specimens showed thickning of the adventitia. Disturbances of the inferior alveolar nerve and artery in this experiment were generally reversible, probably owing to slight damage to the microcirculation in the mandibular canal. Repeated insertion resulted in the greater severity of the damage and more delay in healing. Less
Research Products (10 results)