BEUDAMED
    FDA Adverse Event Injury Summary report: N

    NSK

    MDR report key: 19348671 · Received May 19, 2024

    Report

    Report Number
    9611253-2024-00025
    Event Type
    Injury
    Date Received
    May 19, 2024
    Date of Event
    April 19, 2024
    Report Date
    June 24, 2024
    Manufacturer
    NAKANISHI INC.
    Product Code
    KMW
    Adverse Event
    Yes
    Product Problem
    Yes
    Report Source
    Manufacturer report
    Reporter Location
    JA
    Reporter Occupation
    DENTIST
    Health Professional
    Yes

    Narratives

    Additional Manufacturer Narrative · 0

    THIS EVENT OCCURRED IN JAPAN, BUT SIMILAR PRODUCTS ARE MARKETED IN THE US UNDER K173905. THE DENTIST REFUSED TO PROVIDE INFORMATION ABOUT THEIR AGE, GENDER, WEIGHT.

    Additional Manufacturer Narrative · 0

    UPON RECEIVING THE DEVICE INVOLVED IN THE MDR EVENT, NAKANISHI CONDUCTED A FAILURE ANALYSIS OF THE RETURNED DEVICE, WHICH INCLUDED MEASURING THE OPERATING TEMPERATURE OF THE DEVICE [REPORT NO. C240422-03]. THESE ACTIVITIES ARE DESCRIBED IN MORE DETAIL BELOW. METHODOLOGY USED: A) NAKANISHI EXAMINED THE DEVICE HISTORY RECORD AND THE REPAIR HISTORY FOR THE SUBJECT SG80M DEVICE (B)(6). THERE WERE NO PROBLEMS OBSERVED DURING MANUFACTURING OR TESTING NOTED IN THE DHR. THERE WERE ALSO NO REPAIR HISTORY RECORDS SINCE THE DEVICE WAS SHIPPED. B) NAKANISHI CONDUCTED TEMPERATURE TESTING OF THE RETURNED DEVICE IN THE FOLLOWING MANNER: B.1) TEMPERATURE SENSORS WERE ATTACHED TO THE EXTERIOR OF THE DEVICE AT TWO TEST POINTS. THIS INCLUDED THE POINT CLOSE TO THE HANDPIECE (TESTING POINT (5)) AND POINT CLOSE TO CENTER OF THE DEVICE (TESTING POINTS (6)). THE TEST SETUP WAS PREPARED TO TAKE TEMPERATURE MEASUREMENTS AT THE TWO POINTS SIMULTANEOUSLY, INCLUDING A REFERENCE MEASUREMENT AT AMBIENT ROOM TEMPERATURE. B.2) NAKANISHI ATTACHED A THERMOCOUPLE (SENSOR TO MEASURE TEMPERATURE) TO EACH OF THE TESTING POINTS. NAKANISHI ROTATED THE DEVICE AT 30,000 MIN-1, WHICH IS THE SAME RPM AS ROTATION SPEED AT THE TIME OF THE EVENT FOR THE MOTOR AND MEASURED THE EXOTHERMIC RESPONSE. B.3) NAKANISHI MEASURED THE TEMPERATURE RISE OF THE RETURNED MOTOR SET AT 30,000MIN-1. NAKANISHI OBSERVED RISES IN TEMPERATURE AT THE TEST POINTS AS SHOWN BELOW; HOWEVER, THE TEMPERATURES WERE NOT HIGH ENOUGH TO CAUSE A BURN INJURY. THE MAXIMUM TEMPERATURE MEASURED 5 MINUTES INTO THE TEST WERE AS FOLLOWS: - TEST POINT (5): 38.1 DEGREES C - TEST POINT (6): 38.5 DEGREES C IDENTIFICATION OF THE SPECIFIC FAILURE MODE(S) AND/OR MECHANISM(S) OF THE ASSOCIATED DEVICE COMPONENTS WAS CONDUCTED AS FOLLOWS: A) NAKANISHI DISASSEMBLED THE MOTOR AND PERFORMED A VISUAL INSPECTION OF THE INTERNAL PARTS. NAKANISHI OBSERVED THE FOLLOWING: - THE INSIDE OF THE INSERT WAS SOILED. B) NAKANISHI TOOK PHOTOGRAPHS OF ALL THE DISASSEMBLED PARTS AND KEPT THEM IN THE INVESTIGATION REPORT NO. C240422-03. CONCLUSIONS REACHED BASED ON THE INVESTIGATION AND ANALYSIS RESULTS: A) NAKANISHI COULD NOT IDENTIFY THE EXACT CAUSE OF OVERHEATING OF THE RETURNED DEVICE BECAUSE NAKANISHI WAS NOT ABLE TO REPLICATE THE TEMPERATURE RISE AT THE TIME OF THE EVENT AND DID NOT OBSERVE ANY ABNORMALITIES IN THE VISUAL INSPECTION. B) IN SPITE OF THE FACT THAT NAKANISHI COULD NOT IDENTIFY THE CAUSE, NAKANISHI TOOK THE FOLLOWING ACTIONS TO BE SAFE: C.1) NAKANISHI REVIEWED THE OPERATION MANUAL AND RECONFIRMED THE CLARITY AND UNDERSTANDABILITY OF THE INSTRUCTIONS. C.2) NAKANISHI REPORTED THE ABOVE EVALUATION RESULTS TO THE DENTIST AND REMINDED THE DENTIST OF THE IMPORTANCE OF PERUSE CHECK AND OF MAINTENANCE, AS INSTRUCTED IN THE OPERATION MANUAL.

    Description of Event or Problem · 0

    ON APRIL 22, 2024, NAKANISHI RECEIVED A PHONE CALL FROM A DENTIST ABOUT AN NSK MOTOR OVERHEATING. THE DETAILS NAKANISHI OBTAINED ARE AS FOLLOWS. THE EVENT OCCURRED ON APRIL 19, 2024. THE DENTIST WAS EXTRACTING IMPACTED WISDOM TEETH OF THE PATIENT'S UPPER AND LOWER JAW USING THE SG80M MOTOR (SERIAL NO. (B)(6)) AND X-SG65L HANDPIECE (SERIAL NO. (B)(6)). DURING THE PROCEDURE, THE MOTOR OVERHEATED, AND THE DENTIST RECEIVED A BURN INJURY TO THEIR FINGERS. THE INJURY HAS BEEN HEALED WITHOUT NEED FOR ADDITIONAL MEDICAL TREATMENT. ACCORDING TO THE DENTIST, THERE WERE NO ABNORMALITIES OBSERVED IN THE DEVICE PRIOR TO USE.

    Devices

    Seq Brand Generic Product Code Manufacturer Model Lot UDI-DI
    1161363 NSK HANDPIECE, ROTARY BONE CUTTING KMW NAKANISHI INC. SG80M

    Patients

    Seq Age Sex Outcome Treatment
    1 NA Male Other