The inferior alveolar nerve block is the most common method of local anesthesia for intraoral surgery at the posterior mandibular region. However, unexpected complications may occur when administering the local anesthesia. One of these uncommon complications is the fracture of the needle. If the injection needle is broken during the surgery, it should be removed immediately. However, this is one of the most difficult procedures. In this report, we present two cases of needle fracture during the procedure, and its successful removal under general/local anesthesia administration.
Anesthesia ; Anesthesia, Local ; Mandibular Nerve* ; Methods ; Needles* ; Nerve Block

Purpose: Cention N (Ivoclar Vivadent) was a recently introduced alkasite-based restorative material that was expected to replace amalgam and glass ionomer cement. This material was an esthetic restoration with adequate mechanical strength and release of fluoride and calcium. The purpose of this study was to measure the water sorption and water solubility of Cention N and evaluate its long-term durability compared to other esthetic restorations (Resin-Modified Glass Ionomer cement [RMGIC], Giomer, Composite Resin). Materials and Methods: Twenty specimens each of Cention N (CN), Resin Modified-Glass Ionomer Cement (FJ), Giomer (BF), and Composite Resin (FZ) were made. After each specimen was completely dried in a desiccator for 24 hours using a vacuum pressure pump, the specimen was weighed (m1). After that, the specimen was immersed in distilled water at 37°C for 7 days, stored in a drying oven, and weighed (m2). After drying completely for 24 hours in a desiccator, the specimen was weighed (m3) to calculate the water absorption and water solubility using Formulas 1 and 2. The measured values were statistically processed and analyzed using SPSS, and the significance level was set at 0.05.Result: When measuring water sorption, FJ (122.61 μg/mm3 ) showed significantly higher water sorption than CN (35.42 μg/mm3 ) (P<0.05). There was no significant difference between FZ (18.03 μg/mm3 ) and BF (14.76 μg/mm3 ) (P=0.930). When measuring water solubility, CN (6.65 μg/mm3 ) showed significantly higher water solubility than FJ (1.47 μg/mm3 ) (P<0.05). Conclusion Cention N had lower water sorption than RMGIC, but higher water solubility, indicating that it is more vulnerable to moisture and has lessened long-term durability.