BEUDAMED
    FDA Adverse Event Malfunction Summary report: N

    NSK

    MDR report key: 6287878 · Received January 30, 2017

    Report

    Report Number
    9611253-2017-00006
    Event Type
    Malfunction
    Date Received
    January 30, 2017
    Date of Event
    January 7, 2017
    Report Date
    September 19, 2017
    Manufacturer
    NAKANISHI INC.
    Product Code
    EGS
    PMA / PMN Number
    K972569
    Adverse Event
    Yes
    Product Problem
    Yes
    Report Source
    Manufacturer report
    Reporter Location
    TX, US
    Reporter Occupation
    DENTIST

    Narratives

    Additional Manufacturer Narrative · 0

    EXEMPTION NUMBER E2016004. NAKANISHI INC. (MANUFACTURER) IS SUBMITTING THIS REPORT ON BEHALF OF (B)(4). (B)(4) IS LISTED HERE IN H-10 AND (B)(4) IN G.1 BECAUSE (B)(4) IS THE OFFICIAL CORRESPONDENT OF BOTH NAKANISHI INC. AND (B)(4).

    Description of Event or Problem · 0

    ON (B)(6) 2017, NAKANISHI RECEIVED AN EMAIL FROM A DISTRIBUTOR ((B)(4)) DESCRIBING A HANDPIECE HEAD CAP HAD COME OFF IN A PATIENT'S MOUTH. DETAILS ARE AS FOLLOWS. ON (B)(6) 2017, (B)(4) WAS MADE AWARE OF AN UNCONFIRMED PATIENT INJURY BY AN (B)(4) SALES REPRESENTATIVE: THE (B)(4) SALES REPRESENTATIVE COMMUNICATED THAT THE HEAD CAP OF THE HANDPIECE CAME OFF DURING USE; THE (B)(4) SALES REPRESENTATIVE PROVIDED A CONTACT NUMBER FOR THE DENTIST AT THAT TIME, AND (B)(4) IMMEDIATELY CONTACTED THE DENTIST BY PHONE; THE DENTIST STATED THAT THERE WAS NO INJURY TO THE PATIENT; (B)(4) EMAILED THE DENTIST TO OBTAIN MORE INFORMATION, AND THE (B)(4) PATIENT INFORMATION FORM WAS IMMEDIATELY FORWARDED TO THE DENTIST TO BE COMPLETED; ON (B)(6) 2017, (B)(4) SENT ANOTHER EMAIL REQUESTING PATIENT INFORMATION, BUT THERE WAS NO RESPONSE FROM THE DENTIST; ON (B)(6) 2017, (B)(4) RECEIVED THE INFORMATION FROM THE DENTIST, AND THE DETAILS ARE AS FOLLOWS. THE EVENT OCCURRED ON (B)(6) 2017. THE PROCEDURE AT THE TIME OF THE EVENT WAS A FILLING/RESTORATION PROCEDURE. THE PATIENT WAS NOT UNDER ANY SEDATION OR ANESTHESIA. THERE WAS NO INDICATION OF ANY ABNORMALITY OR MALFUNCTION WITH THE HANDPIECE PRIOR TO USE. THERE WAS NO INJURY TO THE PATIENT. ACCORDING TO THE DENTIST, NO TREATMENT WAS ADMINISTERED, AND NO FOLLOW UP WAS NECESSARY FOR THE PATIENT.

    Additional Manufacturer Narrative · 1

    UPON RECEIVING THE DEVICE INVOLVED IN THE MDR EVENT FROM A DISTRIBUTOR, NAKANISHI CONDUCTED A FAILURE ANALYSIS OF THE RETURNED DEVICE [C170119-01-1]. 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 [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. OTHER THAN WASHERS MISSING FROM THE HANDPIECE WHEN THE DEVICE WAS RETURNED, THERE WERE NO VISIBLE ABNORMALITIES, SUCH AS CRACKS, DENTS OR DEFORMATION, ON THE OUTSIDE OF THE HANDPIECE. NAKANISHI ALSO OBSERVED NO ABRASIONS, DETERIORATION OR DIMENSIONAL ABNORMALITY OF THREADS OF THE HEAD/HEADCAP IN THE VISUAL INSPECTION. NAKANISHI OBSERVED WHETHER OR NOT A HEADCAP ATTACHED TO THE RETURNED HANDPIECE WOULD LOOSEN UNDER THE FOLLOWING CONDITIONS. NEW WASHERS WERE USED FOR THIS TESTING BECAUSE THE WASHERS INVOLVED IN THE EVENT WERE NOT RETURNED. TIGHTENING TORQUE: 50NCM (SPECIFICATION AT THE MANUFACTURING)/45NCM/35NCM/30NCM/25NCM/20NCM/15NCM/10NCM/5NCM. BUR: TEST BUR (DIA.: 1.598MM, LENGTH: 19.01MM)/2 CARBIDE BURS (DIA.: 1.594MM, LENGTH: 19.40MM & DIA.: 1.594MM, LENGTH: 19.42MM)/DIAMOND BUR (DIA.: 1.592MM, LENGTH: 19.18MM). MOTOR ROTATION SPEED: TEST BUR (40,000RPM)/CARBIDE BUR (40,000RPM)/DIAMOND BUR (16,000RPM). LOAD: UNDER NO-LOAD AND UNDER LOAD (LINE ENGRAVING OF PHOSPHOR BRONZE/MELAMINE PLATE). EVALUATION PERIOD: 3 MINUTES FOR EACH EVALUATION UNDER NO-LOAD AND LOAD. NAKANISHI DREW A LINE ON THE HEADCAP AND HEAD AND OBSERVED FOR MISALIGNMENT AFTER EACH USE. THERE WAS NO HEADCAP LOOSENING OBSERVED UNDER ANY CONDITIONS DESCRIBED ABOVE IN THE EVALUATION. CONCLUSIONS REACHED BASED ON THE INVESTIGATION AND ANALYSIS RESULTS: ALTHOUGH NAKANISHI COULD NOT REPLICATE THE REPORTED EVENT, NAKANISHI CONSIDERS THE POSSIBILITY, FROM SIMILAR PHENOMENON NSK HAS OBSERVED IN THE PAST, THAT THE COMBINATION OF A REDUCTION IN HEADCAP TIGHTENING FORCE WITH ABNORMAL VIBRATION (E.G. BUR RUNOUT, CUTTING UNDER HIGH LOAD, ETC.) COULD RESULT IN THE REPORTED HEADCAP LOOSENING/COMING OFF. FAILURE TO CHECK THE HEADCAP TIGHTENESS BEFORE EACH USE AS INSTRUCTED IN THE OPERATION MANUAL, CONTRIBUTES TO THE HEADCAP LOOSENING/COMING OFF WHEN COMBINED WITH ABNORMAL VIBRATION. IN ORDER TO PREVENT A RECURRENCE OF THE HEADCAP LOOSENING/COMING OFF, 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 NSK AMERICA AND DIRECTED NSK AMERICA TO REMIND THE USER OF THE IMPORTANCE OF FOLLOWING INSTRUCTIONS IN THE OPERATION MANUAL.

    Devices

    Seq Brand Generic Product Code Manufacturer Model Lot UDI-DI
    68695 NSK HANDPIECE, CONTRA-AND RIGHT-ANGLE ATTACHMENT, DENTAL EGS NAKANISHI INC. Z95L

    Patients

    Seq Age Sex Outcome Treatment
    1 22 YR Other