Targeted Delivery of Anesthetic Agents to Bone Tissues using Conductive Microneedles Enhanced Iontophoresis for Painless Dental Anesthesia

• Published in: Advanced functional materials 2021-11, Vol.31 (47), p.n/a
• Main Authors: Seeni, Razina Z., Zheng, Mengjia, Lio, Daniel Chin Shiuan, Wiraja, Christian, Mohd Yusoff, Mohammad Firdaus Bin, Koh, William Teck Yeow, Liu, Yuchun, Goh, Bee Tin, Xu, Chenjie
• Format: Article
• Language: English
• Subjects: Anesthesia; Arrays; bones; Dentistry; drug delivery; iontophoresis; Local anesthesia; Materials science; microneedles; Needles; Nerves; Pain; Syringes
• ISSN: 1616-301X; 1616-3028
• DOI: 10.1002/adfm.202105686

Pain management during dental procedures is a cornerstone for successful daily practice. In current practice, the traditional needle and syringe injection is used to administer local anesthesia. However, the appearance of long needles and the pain associated with it often leads to dental anxiety deterring timely interventions. Microneedles (MNs) have emerged as a minimally invasive alternative to hypodermic needles and shown to be effective in transdermal drug delivery applications. In this article, the potential use of MNs for local anesthesia delivery in dentistry is explored. The development of a novel conductive MN array that can be used in combination with iontophoresis technique to achieve drug penetration through the oral mucosa and the underlying bone tissue is presented. The conductive MN array plays a dual‐role, creating micro‐conduits and lowering the resistance of the oral mucosa. The reduced tissue resistance further enhances the application of a low‐voltage current that is able to direct and accelerate the drug molecules to target the sensory nerves supplying teeth. The successful delivery of lidocaine using this new strategy in a clinically relevant rabbit incisor model is shown to be as effective as the current gold standard. As an alternative to the traditional needle and syringe for dental anesthesia delivery, a novel conductive microneedle array, is designed to significantly lower oral mucosal tissue resistance and amplify the effects of simultaneous application of iontophoresis. When applied on a rabbit incisor, the onset of the anesthetic effect is immediate and achieves a duration of action similar to that of the conventional method.