BEUDAMED
    FDA Adverse Event Injury Summary report: N

    NSK

    MDR report key: 18994515 · Received March 28, 2024

    Report

    Report Number
    9611253-2024-00016
    Event Type
    Injury
    Date Received
    March 28, 2024
    Date of Event
    January 16, 2024
    Report Date
    August 21, 2024
    Manufacturer
    NAKANISHI INC.
    Product Code
    KMW
    PMA / PMN Number
    K171155
    Removal / Correction Number
    9611253-060818-001-R
    Adverse Event
    Yes
    Product Problem
    Yes
    Report Source
    Manufacturer report
    Reporter Location
    PA, 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, WHICH INCLUDED MEASURING THE OPERATING TEMPERATURE OF THE DEVICE [REPORT NO. C240309-01]. THESE ACTIVITIES ARE DESCRIBED IN MORE DETAIL BELOW. METHODOLOGY USED: A) NAKANISHI EXAMINED THE DEVICE HISTORY RECORD AND THE REPAIR HISTORY FOR THE SUBJECT SGS-E2S DEVICE [ABE10048]. 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 VARIOUS TEST POINTS. THIS INCLUDED THE POINT MOST PROXIMAL TO THE PATIENT (TESTING POINT (1)) AND POINTS FURTHER TOWARD THE DISTAL END OF THE DEVICE (TESTING POINTS (2) THROUGH (4)). THE TEST SETUP WAS PREPARED TO TAKE TEMPERATURE MEASUREMENTS AT ALL 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'S MOTOR AT 40,000MIN-1, WHICH IS THE MAXIMUM RPM FOR THE MOTOR THAT DRIVES THE HANDPIECE (80,000MIN-1 FOR THE HANDPIECE), WITHOUT WATER SPRAY, AND MEASURED THE EXOTHERMIC RESPONSE. B.3) NAKANISHI MEASURED THE TEMPERATURE RISE OF THE RETURNED HANDPIECE SET AT 80,000MIN-1 (MOTOR REVOLUTION 40,000MIN-1). NAKANISHI OBSERVED AN ABNORMAL TEMPERATURE RISE AT THE TEST POINT (1) 20 SECONDS AND (2) 50 SECONDS INTO THE TEST. TEMPERATURE MEASUREMENTS ABOUT 60 SECONDS AFTER THE START OF THE TEST WERE AS FOLLOWS: - TEST POINT (1): 87.4 DEGREES C. - TEST POINT (2): 61.0 DEGREES C. - TEST POINT (3): 35.4 DEGREES C. - TEST POINT (4): 40.9 DEGREES C. THE INCREASE IN TEMPERATURE WAS SO SUDDEN THAT THE TEST WAS CONCLUDED ABOUT 60 SECONDS INTO THE PLANNED 5-MIMUTE EVALUATION PERIOD. IDENTIFICATION OF THE SPECIFIC FAILURE MODE(S) AND/OR MECHANISM(S) OF THE ASSOCIATED DEVICE COMPONENTS WAS CONDUCTED AS FOLLOWS: A) NAKANISHI DISASSEMBLED THE HANDPIECE AND PERFORMED A VISUAL INSPECTION OF THE INTERNAL PARTS. NAKANISHI OBSERVED THAT THE BEARING WAS SOILED AND BROKEN. B) NAKANISHI TOOK PHOTOGRAPHS OF ALL THE DISASSEMBLED PARTS AND KEPT THEM IN THE INVESTIGATION REPORT NO. C240309-01. CONCLUSIONS REACHED BASED ON THE INVESTIGATION AND ANALYSIS RESULTS: A) NAKANISHI DETERMINED THAT THE CAUSE OF THE HANDPIECE OVERHEATING WAS ABNORMAL RESISTANCE DURING ROTATION DUE TO THE BROKEN BEARING. NAKANISHI CONSIDERS THE POSSIBILITY FROM MANY YEARS OF EXPERIENCE THAT THE CAUSE OF THE BROKEN BEARING WAS THE INGRESS OF UNDESIRABLE MATERIALS INTO THE BEARING, LEADING TO ABRASION. B) A LACK OF MAINTENANCE CAUSED THE ACCUMULATION OF DEBRIS ON THE INTERNAL PARTS, WHICH CAUSED DEBRIS INGRESS INTO THE BEARING DURING ROTATION. THIS CONTRIBUTED TO THE HANDPIECE OVERHEATING. C) IN ORDER TO PREVENT A RECURRENCE OF THE HANDPIECE OVERHEATING, NAKANISHI TOOK THE FOLLOWING ACTIONS: 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 DISTRIBUTOR AND DIRECTED THE DISTRIBUTOR TO REMIND THE USER OF THE IMPORTANCE OF MAINTENANCE 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, (B)(4), UNDER REPORT NUMBER (B)(4). THE DENTIST REFUSED TO PROVIDE ANY INFORMATION ABOUT THE PATIENT.

    Description of Event or Problem · 0

    ON MARCH 9, 2024, NAKANISHI BECAME AWARE OF A HANDPIECE OVERHEATING THROUGH A COMPLAINT INPUT INTO THE COMPLAINT DATABASE BY A DISTRIBUTOR ((B)(4)). ACCORDING TO THE DISTRIBUTOR, THERE ARE THREE DEVICES SUSPECTED TO BE INVOLVED IN THE EVENT, BUT THE DENTIST COULD NOT IDENTIFY WHICH ONE OF THE DEVICES ACTUALLY CAUSED THE FOLLOWING EVENT. THEREFORE, NAKANISHI IS SUBMITTING THREE SEPARATE MDRS FOR THIS EVENT. THIS MDR IS REGARDING THE HANDPIECE WITH THE SERIAL NUMBER ABE10048. DETAILS ARE AS FOLLOWS: - THE EVENT OCCURRED ON JANUARY 16, 2024. - THE DENTIST WAS PERFORMING A SURGICAL THIRD MOLAR EXTRACTION PROCEDURE ON A PATIENT USING THE SGS-E2S HANDPIECE (SERIAL NO. (B)(6)) - DURING THE PROCEDURE, THE SURGICAL HANDPIECE OVERHEATED, AND THE PATIENT RECEIVED A SECOND DEGREE BURN TO THEIR LIP. - THE PATIENT WAS TREATED FOR THE BURN INJURY IN THE ER AT THE TIME OF THE INCIDENT AND WAS RECOMMENDED TO FOLLOW UP WITH THE BURN CENTER IF NECESSARY. - THE DENTIST HAS NOT BEEN MADE AWARE OF THE NEED FOR ADDITIONAL MEDICAL TREATMENT OR COMPLICATIONS FROM THE INJURY SINCE THE INCIDENT.

    Devices

    Seq Brand Generic Product Code Manufacturer Model Lot UDI-DI
    715539 NSK HANDPIECE, ROTARY BONE CUTTING KMW NAKANISHI INC. SGS-E2S

    Patients

    Seq Age Sex Outcome Treatment
    1 NA Unknown Other