BEUDAMED
    FDA Adverse Event Malfunction Summary report: N

    NSK

    MDR report key: 15664622 · Received October 25, 2022

    Report

    Report Number
    9611253-2022-00076
    Event Type
    Malfunction
    Date Received
    October 25, 2022
    Date of Event
    September 26, 2022
    Report Date
    December 1, 2022
    Manufacturer
    NAKANISHI INC.
    Product Code
    EGS
    PMA / PMN Number
    K972569
    Product Problem
    Yes
    Report Source
    Manufacturer report
    Reporter Location
    IL, US
    Reporter Occupation
    501

    Narratives

    Additional Manufacturer Narrative · 0

    UPON RECEIVING THE DEVICE INVOLVED IN THE MDR EVENT FROM THE DISTRIBUTOR, NAKANISHI CONDUCTED A FAILURE ANALYSIS OF THE RETURNED DEVICE [REPORT NO. C221004-01]. THESE ACTIVITIES ARE DESCRIBED IN MORE DETAIL BELOW. METHODOLOGY USED: NAKANISHI EXAMINED THE DEVICE HISTORY RECORD AND THE REPAIR HISTORY FOR THE SUBJECT Z95L DEVICE [ABE40094]. 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. NAKANISHI DISASSEMBLED THE HANDPIECE AND CONDUCTED A VISUAL INSPECTION OF THE INTERNAL PARTS. NAKANISHI OBSERVED THAT THE CARTRIDGE AND THE DRIVE SHAFT WERE SOILED AND ABRADED. NAKANISHI MOUNTED A NEW CARTRIDGE TO THE HEAD OF THE HANDPIECE AND ROTATE THE HANDPIECE UNDER NO LOAD AND CUT A MELAMINE PLATE WHILE ROTATING THE HANDPIECE MOTOR AT THE MAXIMUM SPEED (200,000MIN-1) TO CHECK WHETHER OR NOT THE HEADCAP WOULD LOOSEN. THE REPORTED LOOSENING OF THE HEADCAP WAS NOT REPLICATED IN THE DEVICE EVALUATION. NAKANISHI TOOK PHOTOGRAPHS OF ALL THE DISASSEMBLED PARTS AND KEPT THEM IN THE INVESTIGATION REPORT NO. C221004-01. CONCLUSIONS REACHED BASED ON THE INVESTIGATION AND ANALYSIS RESULTS: ALTHOUGH NAKANISHI COULD NOT REPLICATE THE REPORTED EVENT, NAKANISHI CONSIDERS THE POSSIBILITY FROM SIMILAR EVENT THAT NSK HAS EXPERIENCED IN THE PAST, THE COMBINATION OF A STRONG IMPACT ON THE DEVICE TOGETHER WITH CUTTING VIBRATION COULD RESULT IN THE REPORTED HEADCAP LOOSENING/SEPARATION. MISUSE BY THE USER LED TO THE ABOVE ISSUE, WHICH CONTRIBUTED TO THE REPORTED EVENT. IN ORDER TO PREVENT A RECURRENCE OF THE HEADCAP LOOSENING/SEPARATION, NAKANISHI TOOK THE FOLLOWING ACTIONS: NAKANISHI REVIEWED THE OPERATION MANUAL AND RECONFIRMED THE CLARITY AND UNDERSTANDABILITY OF THE INSTRUCTIONS. NAKANISHI WILL REPORT THE ABOVE EVALUATION RESULTS TO THE DISTRIBUTOR AND DIRECTED THE DISTRIBUTOR TO REMIND THE USER OF THE IMPORTANCE OF USING THE DEVICE AS INSTRUCTED IN THE OPERATION MANUAL.

    Additional Manufacturer Narrative · 0

    THE SAME ADVERSE EVENT IN THIS REPORT HAS BEEN REPORTED TO THE FDA SEPARATELY BY THE DISTRIBUTOR, NSK AMERICA CORPORATION, UNDER REPORT NUMBER (B)(4).

    Description of Event or Problem · 0

    ON (B)(6) 2022, NAKANISHI BECAME AWARE OF A MALFUNCTION OF A NSK HANDPIECE THROUGH A COMPLAINT INPUT INTO THE COMPLAINT DATABASE BY A DISTRIBUTOR (NSK AMERICA). DETAILS ARE AS FOLLOWS: THE EVENT OCCURRED ON (B)(6) 2022. A DENTIST WAS PERFORMING A CROWN PREPARATION PROCEDURE ON A TOOTH IN THE UPPER LEFT QUADRANT OF A PATIENT USING THE Z95L HANDPIECE (SERIAL NO. (B)(4)). DURING THE PROCEDURE, THE HEAD CAP OF THE HANDPIECE CAME OFF INSIDE THE PATIENT'S MOUTH. THE HEAD CAP WAS RECOVERED IMMEDIATELY, AND THE PATIENT WAS NOT AFFECTED. THE DENTIST SWITCHED TO A DIFFERENT HANDPIECE AND THE PROCEDURE WAS COMPLETED SUCCESSFULLY.

    Devices

    Seq Brand Generic Product Code Manufacturer Model Lot UDI-DI
    2351275 NSK HANDPIECE, CONTRA- AND RIGHT-ANGLE ATTACHMENT, DENTAL EGS NAKANISHI INC. Z95L

    Patients

    Seq Age Sex Outcome Treatment
    1 Unknown Other