BEUDAMED
    FDA Adverse Event Injury Summary report: N

    NSK

    MDR report key: 6776587 · Received August 9, 2017

    Report

    Report Number
    9611253-2017-00039
    Event Type
    Injury
    Date Received
    August 9, 2017
    Date of Event
    July 7, 2017
    Report Date
    April 5, 2018
    Manufacturer
    NAKANISHI INC.
    Product Code
    EGS
    Adverse Event
    Yes
    Product Problem
    Yes
    Report Source
    Manufacturer report
    Reporter Location
    JA
    Reporter Occupation
    OTHER

    Narratives

    Additional Manufacturer Narrative · 0

    THE DENTIST REFUSED TO PROVIDE INFORMATION ABOUT THE PATIENT'S WEIGHT. UPON RECEIVING THE DEVICE INVOLVED IN THE MDR EVENT FROM A DISTRIBUTOR, NAKANISHI CONDUCTED A FAILURE ANALYSIS OF THE RETURNED DEVICE [C170727-02]. THESE ACTIVITIES ARE DESCRIBED IN MORE DETAIL BELOW. METHODOLOGY USED: NAKANISHI EXAMINED THE DEVICE HISTORY RECORD AND THE REPAIR HISTORY FOR THE SUBJECT DA-280C DEVICE [SERIAL NUMBER (B)(4)]. THERE WERE NO PROBLEMS OBSERVED DURING THE MANUFACTURING OR TESTING NOTED IN THE DHR. THERE WERE ALSO NO REPAIR HISTORY RECORDS SINCE THE DEVICE WAS SHIPPED. NAKANISHI CONDUCTED A VISUAL INSPECTION OF THE RETURNED DEVICE AND OBSERVED LOOSENING OF THE HEADCAP SCREW AND THE UNION RING SCREW. NAKANISHI ALSO CHECKED THE BUR ENGAGEMENT STATE BY PULLING THE BUR BY HAND. THE BUR WAS ENGAGED WITH THE CHUCK ENOUGH NOT TO COME OUT OF THE HANDPIECE. NAKANISHI MEASURED THE BUR RETENTION FORCE USING A MEASURING INSTRUMENT TO CONFIRM WHETHER OR NOT THE FORCE MEETS THE ISO7785-2 CRITERIA, WHICH IS 45N OR GREATER. THE RETENTION FORCE OBSERVED IN THE MEASUREMENT WAS 90N. NAKANISHI TRIED CUTTING A COPPER PLATE AND MELAMINE USING THE SUBJECT BUR ATTACHED TO THE RETURNED HANDPIECE TO SEE WHETHER OR NOT THE BUR WOULD COME OUT. NAKANISHI DID NOT OBSERVE ANY BUR COMING OUT IN THE EVALUATION. NAKANISHI MEASURED THE DIAMETER AND LENGTH OF THE BUR SHANK AND CONFIRMED THAT THE BUR WAS COMPLIANT WITH ISO7785-2. IDENTIFICATION OF THE SPECIFIC FAILURE MODE(S) AND/OR MECHANISM(S) AND THE ASSOCIATED DEVICE COMPONENTS INVOLVED: NAKANISHI DISASSEMBLED THE HANDPIECE AND PERFORMED A VISUAL INSPECTION OF THE INSIDE PARTS. NAKANISHI OBSERVED THE FOLLOWING PHENOMENA: THE LATCH THAT WAS SUPPOSED TO BE FIXED TO THE LATCH RETAINER WITH PINS CAME OUT OF THE LATCH RETAINER. ONE OF THE PINS WAS MISSING. NAKANISHI TOOK PHOTOGRAPHS OF ALL OF THE DISASSEMBLED PARTS AND KEPT THEM IN THE INVESTIGATION REPORT # (B)(4). CONCLUSIONS REACHED BASED ON THE INVESTIGATION AND ANALYSIS RESULTS: ALTHOUGH NAKANISHI COULD NOT REPLICATE THE REPORTED PHENOMENON, NAKANISHI CONSIDERS THE POSSIBILITY, FROM MANY YEARS OF EXPERIENCE THAT THE CAUSE OF THE BUR SEPARATION FROM THE HANDPIECE WAS INSUFFICIENT ENGAGEMENT OF THE BUR WITH THE CHUCK. FAILURE TO CHECK THE BUR STATE PRIOR TO USE COULD CONTRIBUTE TO THE REPORTED EVENT. IN ORDER TO PREVENT A RECURRENCE OF THE BUR COMING OUT, NAKANISHI TOOK THE FOLLOWING ACTIONS: NAKANISHI REVIEWED THE OPERATION MANUAL AND RECONFIRMED CLARITY AND UNDERSTANDABILITY OF THE INSTRUCTIONS. NAKANISHI REPORTED THE ABOVE EVALUATION RESULTS TO THE DENTIST AND REMINDED THE DENTIST OF THE IMPORTANCE OF PREUSE CHECK TO ENSURE THE SECURE FIXATION OF THE BUR, AS INSTRUCTED IN THE OPERATION MANUAL.

    Description of Event or Problem · 0

    ON AUGUST 22, 2017, NAKANISHI RECEIVED DETAILED INFORMATION ON THE EVENT FROM THE PHARMACEUTICALS AND MEDICAL DEVICES AGENCY, AS FOLLOWS. THE EVENT OCCURRED ON (B)(6) 2017, NOT (B)(6), 2017. THE PROCEDURE THE DENTIST WAS PERFORMING AT THE TIME OF THE EVENT WAS POLISHING DENTAL METAL ON THE UPPER LEFT TOOTH #8 FOR OCCLUSION USING THE SUBJECT HANDPIECE WITH A SILICONE POLISHING POINT BUR. THE PATIENT WAS NOT UNDER ANESTHESIA. DURING THE PROCEDURE, THE BUR SUDDENLY CAME OFF AND DROPPED IN THE PATIENT'S MOUTH. THE PATIENT UNDERWENT A SURGICAL PROCEDURE TO REMOVE THE BUR. ACCORDING TO THE DENTIST, THERE WERE NO ABNORMALITIES OBSERVED IN THE DEVICES INCLUDING THE BUR. THE DENTIST ALSO STATED THAT THE PERIODICAL MAINTENANCE OF THE HANDPIECE WAS NOT PERFORMED.

    Additional Manufacturer Narrative · 1

    NAKANISHI IS STILL COLLECTING INFORMATION ABOUT THE PATIENT AND DETAILS OF THE EVENT. THIS EVENT OCCURRED IN (B)(6), BUT SIMILAR PRODUCTS ARE MARKETED IN THE US UNDER K972569.

    Description of Event or Problem · 1

    ON JULY 27, 2017, AN NSK DA-280C HANDPIECE WAS RETURNED FROM A DISTRIBUTOR TO NAKANISHI FOR REPAIR. THERE WAS A NOTE WITH THE DEVICE STATING A BUR COMING OUT OF THE HANDPIECE. THE DETAILS ARE AS FOLLOWS. - THE EVENT OCCURRED ON (B)(6) 2017. - A DENTIST WAS PERFORMING A DENTAL PROCEDURE USING THE DA-280C HANDPIECE (SERIAL NO.: (B)(4)). - DURING THE PROCEDURE, THE BUR SUDDENLY CAME OUT OF THE HANDPIECE AND DROPPED IN THE PATIENT'S MOUTH.

    Devices

    Seq Brand Generic Product Code Manufacturer Model Lot UDI-DI
    562778 NSK HANDPIECE, CONTRA- AND RIGHT-ANGLE ATTACHMENT, DENTAL EGS NAKANISHI INC. DA-280C

    Patients

    Seq Age Sex Outcome Treatment
    1 85 YR Other| R