BEUDAMED
    FDA Adverse Event Injury Summary report: N

    DA-800C5L

    MDR report key: 5624347 · Received May 2, 2016

    Report

    Report Number
    9611253-2016-00022
    Event Type
    Injury
    Date Received
    May 2, 2016
    Date of Event
    April 12, 2016
    Report Date
    October 24, 2016
    Manufacturer
    NAKANISHI INC.
    Product Code
    EGS
    Adverse Event
    Yes
    Report Source
    Manufacturer report
    Reporter Location
    JA
    Reporter Occupation
    OTHER

    Narratives

    Additional Manufacturer Narrative · 1

    THIS EVENT OCCURED IN (B)(6), BUT THE SIMILAR PRODUCTS ARE MARKETED IN THE US UNDER K972569.

    Additional Manufacturer Narrative · 1

    UPON RECEIVING THE DEVICE INVOLVED IN THE ADVERSE EVENT, NAKANISHI CONDUCTED A FAILURE ANALYSIS OF THE RETURNED DEVICE: METHODOLOGY USED: NAKANISHI EXAMINED THE DEVICE HISTORY RECORD FOR THE SUBJECT DA-800C5L DEVICE (SERIAL NUMBER (B)(4)). THERE WERE NO PROBLEMS OBSERVED DURING THE MANUFACTURING OR TESTING NOTED IN THE DHR. THERE WERE NO REPAIR HISTORY RECORDS SINCE THE DEVICE WAS SHIPPED. INVESTIGATION OF OVERHEATING TEMPERATURE SENSORS WERE FIRST ATTACHED TO THE EXTERIOR OF THE DEVICE AT VARIOUS TEST POINTS (I.E. MOST PROXIMAL TO THE PATIENT, TESTING POINT (1), AND ALONG POINTS FURTHER TOWARDS THE DISTAL END OF THE DEVICE, TESTING POINTS (2) THROUGH (4)). THE TEST WAS SET UP TO TAKE TEMPERATURE MEASUREMENTS AT ALL POINTS SIMULTANEOUSLY, INCLUDING A REFERENCE MEASUREMENT AT AMBIENT ROOM TEMPERATURE. NAKANISHI ATTACHED A THERMOCOUPLE (SENSOR TO MEASURE TEMPERATURE) TO EACH POINT. NAKANISHI ROTATED THE MOTOR AT 40,000 MIN-1, WHICH IS MAXIMUM RPM FOR THE MOTOR THAT DRIVES THE HANDPIECE (200,000 MIN-1 FOR THE HANDPIECE), WITH WATER SPRAY, AND MEASURED THE EXOTHERMIC SITUATION. NAKANISHI OBSERVED ABNORMAL TEMPERATURE RISES AT TEST POINTS (1) AND (2) 42 SECONDS AFTER THE START. TEMPERATURE MEASUREMENTS 42 SECONDS AFTER THE START ARE AS FOLLOWS: TEST POINT (1): 55.7 DEGREES C, TEST POINT (2): 70.5 DEGREES C, TEST POINT (3): 31.5 DEGREES C, TEST POINT (4): 32.0 DEGREES C. THE TEMPERATURE TESTING WAS CONDUCTED FOR ONLY 42 SECONDS INTO THE PLANNED 5 MINUTE EVALUATION. IDENTIFICATION OF THE SPECIFIC FAILURE MODE(S) AND/OR MECHANISM(S) : NAKANISHI DISASSEMBLED THE HANDPIECE AND PERFORMED A VISUAL INSPECTION OF THE INSIDE PARTS. NAKANISHI OBSERVED THAT THE BEARING RETAINER (BALL RETAINING PLASTIC PART) WAS BROKEN. NAKANISHI ALSO OBSERVED RUST AND CORROSION INSIDE OF THE CARTRIDGE, AND BROKEN PARTS ON THE GEAR AT THE MESHING PORTION INSIDE OF THE CARTRIDGE. NAKANISHI TOOK PHOTOGRAPHS OF ALL OF THE DISASSEMBLED PARTS AND KEPT THEM IN A FILE. CONCLUSION REACHED BASED ON THE INVESTIGATION AND ANALYSIS RESULT: NAKANISHI IDENTIFIED THAT THE CAUSE OF THE OVERHEATING OF THE RETURNED DEVICE WAS ABNORMAL RESISTANCE DURING ROTATION CAUSED BY CENTRIFUGAL FORCE DUE TO THE BROKEN BALL RETAINER PLASTIC PART. THE CAUSE OF THE BREAKAGE OF THE BEARING RETAINER WAS HIGH LOAD APPLIED TO THE BEARING RETAINER CAUSED BY THE INGRESS OF DEBRIS FROM THE BROKEN GEAR. A LACK OF MAINTENANCE CAUSES RUST, CORROSION, AND BREAKAGE OF THE INSIDE PARTS. IN ORDER TO PREVENT A RECURRENCE OF THE HANDPIECE OVERHEATING, NAKANISHI TOOK THE FOLLOWING ACTIONS: NAKANISHI REVIEWED THE OPERATION MANUAL AND RECONFIRMED CLARITY AND UNDERSTANDABILITY OF THE INSTRUCTIONS. NAKANISHI REPORTED THE ABOVE EVALUATION RESULT TO THE DISTRIBUTOR AND DIRECTED THE DISTRIBUTOR TO REMIND THE USER OF THE IMPORTANCE OF MAINTAINING AND CHECKING THE HANDPIECE PRIOR TO USE TO PREVENT OVERHEATING, AS INSTRUCTED IN THE OPERATION MANUAL. NAKANISHI CONTACTED THE DISTRIBUTOR FOR PATIENT INFORMATION ON (B)(4) 2016, BUT THE DISTRIBUTOR DID NOT DISCLOSE THE PATIENT ID, AGE, SEX, OR WEIGHT.

    Description of Event or Problem · 1

    ON (B)(6) 2016, A HANDPIECE DA-800C5L (SERIAL NO.(B)(4)) WAS RETURNED FROM A DISTRIBUTOR TO NAKANISHI FOR REPAIR. THERE WAS A NOTE COMING WITH THE HANDPIECE REFERRING TO THE HANDPIECE OVERHEATING. DETAILS ARE AS FOLLOWS. THE EVENT OCCURED ON (B)(6) 2016. THE DENTIST WAS TREATING A TOOTH #6 UPPER RIGHT JAW USING THE DA-800C5L. WHEN THE DENTIST MOVED ON TO THE NEXT TREATMENT ON A FRONT TOOTH, THE HANDPIECE TOUCHED THE PATIENT'S LIP AND THE PATIENT GOT BURNT ON THE LIP. ACCORDING TO THE DENTIST, THERE WAS NO FOLLOW-UP TREATMENT WITH THE PATIENT BECAUSE THE DENTIST DETERMINED THE INJURY WAS MINOR.

    Devices

    Seq Brand Generic Product Code Manufacturer Model Lot UDI-DI
    278481 DA-800C5L HANDPIECE, CONTRA-AND RIGHT ANGLE ATTACHMENT, DENTAL EGS NAKANISHI INC. DA-800C5L

    Patients

    Seq Age Sex Outcome Treatment
    1 Other