BEUDAMED
    FDA Adverse Event Injury Summary report: N

    NSK

    MDR report key: 4942496 · Received July 21, 2015

    Report

    Report Number
    9611253-2015-00102
    Event Type
    Injury
    Date Received
    July 21, 2015
    Report Date
    March 12, 2018
    Manufacturer
    NAKANISHI, INC.
    Product Code
    EGS
    PMA / PMN Number
    K972569
    Report Source
    Manufacturer report
    Reporter Occupation
    OTHER

    Narratives

    Additional Manufacturer Narrative · 1

    UPON RECEIPT FROM NSK AMERICA OF THE DEVICE INVOLVED IN THE MDR EVENT, NAKANISHI CONDUCTED A FAILURE ANALYSIS OF THE RETURNED DEVICE THAT INCLUDED MEASUREMENT OF THE TEMPERATURE OF THE OPERATING DEVICE [C150706-17-01]. THESE ACTIVITIES ARE DESCRIBED IN MORE DETAIL BELOW. METHODOLOGY USED : A) NAKANISHI EXAMINED THE DEVICE HISTORY RECORD FOR THE SUBJECT TI-MAX X95L DEVICE [SERIAL NUMBER (B)(4)]. THERE WERE NO PROBLEMS OBSERVED DURING THE MANUFACTURING OR TESTING NOTED IN THE DHR. B) NAKANISHI CONDUCTED A VISUAL INSPECTION OF THE RETURNED DEVICE AND PERFORMED A SIMPLE MOVEMENT TEST. THERE WERE NO VISIBLE ABNORMALITIES, SUCH AS CRACKS OR DEBRIS, ON THE OUTSIDE OF THE HANDPIECE. NAKANISHI THEN SET A TEST BUR IN THE HANDPIECE AND ROTATE IT BY HAND TO SEE BEARING CONDITION. NAKANISHI OBSERVED THAT THE BUR ROTATED SMOOTHLY. C) NAKANISHI CONDUCTED A TEMPERATURE TESTING OF THE RETURNED DEVICE IN THE FOLLOWING MANNER. C.1) TEMPERATURE SENSORS WERE FIRST ATTACHED TO THE EXTERIOR OF THE DEVICE AT VARIOUS TEST POINTS (E.G., MOST PROXIMAL TO THE PATIENT AND ALONG POINTS FURTHER TOWARD THE DISTAL END OF THE DEVICE). THE TEST SETUP WAS PREPARED TO TAKE TEMPERATURE MEASUREMENTS AT ALL POINTS SIMULTANEOUSLY, INCLUDING A REFERENCE MEASUREMENT AT AMBIENT ROOM TEMPERATURE. C.2) NAKANISHI ATTACHED A THERMOCOUPLE (SENSOR TO MEASURE A TEMPERATURE) TO EACH OF THE TESTING POINTS (A), (B), (C) AND (D). NAKANISHI ROTATED THE HANDPIECE AT 40,000RPM, WHICH IS MAXIMUM RPM FOR THE MOTOR THAT DRIVES THE HANDPIECE (200,000 PRM FOR THE HANDPIECE), WITH WATER SPRAY AND MEASURED THE EXOTHERMIC SITUATION. C.3) NAKANISHI MEASURED THE TEMPERATURE RISE OF THE RETURNED HANDPIECE SET AT 200,000 RPM (MOTOR REVOLUTION 40,000RPM). NAKANISHI CONFIRMED THE TEMPERATURE RISE AT THE TEST POINTS AS FOLLOWS AFTER THE BEGINNING OF THE MEASUREMENT ; (A) 33.5 DEGREES C, (B) 35.6 DEGREES C, (C) 32.6 DEGREES C AND (D) 31.7 DEGREES C. ALL THE TEMPERATURES OBSERVED IN THE MEASUREMENT WERE WITHIN THE NAKANISHI SPECIFICATION RANGE. THEREFORE, NAKANISHI DID NOT OBSERVE ABNORMAL TEMPERATURE AT ANY MEASURING POINT. IDENTIFICATION OF THE SPECIFIC FAILURE MODE(S) AND/OR MECHANISM(S) AND THE ASSOCIATED DEVICE COMPONENT(S) INVOLVED : A) NAKANISHI CLEANED AND LUBRICATED THE INSIDE OF THE HANDPIECE USING NAKANISHI PANA-SPRAY AS DEFINED IN THE OPERATION MANUAL. WHEN SPRAYING, NAKANISHI USED A WHITE FILTER TO CATCH ANYTHING THAT WAS EXPELLED. NAKANISHI DID NOT OBSERVE ANY DIRT/DEBRIS BEING EXPELLED FROM THE HEAD OF THE HANDPIECE. B) NAKANISHI DISASSEMBLED THE HANDPIECE AND PERFORMED A VISUAL INSPECTION OF THE INSIDE PARTS. NAKANISHI DID NOT OBSERVE ANY DAMAGE ON THE INSIDE PARTS. CONCLUSIONS REACHED BASED ON THE INVESTIGATION AND ANALYSIS RESULTS : NAKANISHI DID NOT IDENTIFY THE CAUSE OF OVERHEATING OF THE RETURNED DEVICE BECAUSE NAKANISHI WERE NOT ABLE TO REPLICATE THE TEMPERATURE RISE AT THE TIME OF THE EVENT AND DID NOT OBSERVE ANY ABNORMALITIES IN THE VISUAL INSPECTION.

    Additional Manufacturer Narrative · 1

    ON OCTOBER 14, 2016, NAKANISHI HEARD FROM THE DISTRIBUTOR THAT NO ADDITIONAL INFORMATION REGARDING THE PATIENT WAS AVAILABLE.

    Description of Event or Problem · 1

    (B)(4).

    Devices

    Seq Brand Generic Product Code Manufacturer Model Lot UDI-DI
    470848 NSK HANDPIECE, CONTRA AND RIGHT-ANGLE ATTACHMENT, DENTAL EGS NAKANISHI, INC.

    Patients

    Seq Age Sex Outcome Treatment
    1