• Decrease font size
  • Return font size to normal
  • Increase font size
U.S. Department of Health and Human Services


  • Print
  • Share
  • E-mail
Super Search Devices@FDA
510(k) | DeNovo | Registration & Listing | Adverse Events | Recalls | PMA | HDE | Classification | Standards
CFR Title 21 | Radiation-Emitting Products | X-Ray Assembler | Medsun Reports | CLIA | TPLC

Model Number M800WL
Device Problem Detachment of Device or Device Component (2907)
Patient Problem No Clinical Signs, Symptoms or Conditions (4582)
Event Date 10/19/2020
Event Type  malfunction  
Manufacturer Narrative
Nakanishi did not receive any information about the patient, and is still waiting for the information from the distributor. Upon receiving the device involved in the mdr event from the distributor, nakanishi conducted a failure analysis of the returned device. These activities are described in more detail below. Methodology used: nakanishi examined the device history record and the repair history for the subject m800wl device [serial no. (b)(4)]. 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. Nakanishi conducted a visual inspection of the returned device and observed that the cartridge cap was stuck on the headcap, and both the cartridge cap and headcap were removed from the device. Nakanishi also confirmed that the cartridge case was broken. After replacing the broken cartridge with a new cartridge and setting, the returned headcap in the handpiece, nakanishi observed whether or not the headcap would loosen by rotating and then cutting a melamine plate. There was no headcap loosening observed in the evaluation. Nakanishi, then disassembled the handpiece and performed a visual inspection of the internal parts. Nakanishi observed the following phenomena: there were contact traces produced by friction heat on the surface of the push button. The cartridge bearing was abraded, soiled, and discolored. Nakanishi took photographs of all the disassembled parts and kept them in investigation report #(b)(4). Conclusions reached based on the investigation and analysis results: nakanishi could not replicate the headcap separation at the time of the event, however, based on the abnormality of the internal parts observed in the visual inspection, as well as many years of experience, nakanishi determined that the cause of the reported separation was abnormal vibration generated by contact with the push button or abrasion/debris of the cartridge bearing. In addition, some strong impact on the device or repeated cutting vibration may also have contributed to the headcap loosening. A lack of maintenance caused the accumulation of debris on the internal parts, and failure to check the handpiece before use led to user ignorance of abnormalities in the internal parts, which contributed to the headcap separation. 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 the user and reminded the user of the importance of maintenance and checking of the handpiece prior to use to prevent headcap separation/coming off, as instructed in the operation manual.
Event Description
On october 21, 2020, nakanishi received a phone call from a distributor about a malfunction of an nsk handpiece. The information nakanishi obtained from the communication is as follows: the event occurred on (b)(6) 2020. The dentist was performing a dental procedure on a patient using the m800wl handpiece (serial no. (b)(4)). During the procedure, the headcap separated from the head, and the cartridge came out and fell in the patient mouth.
Search Alerts/Recalls

  New Search  |  Submit an Adverse Event Report

Brand NameNSK
Manufacturer (Section D)
700 shimohinata
kanuma-shi, tochigi-ken 322-8 666
JA 322-8666
Manufacturer (Section G)
700 shimohinata
kanuma-shi, tochigi-ken 322-8 666
JA 322-8666
Manufacturer Contact
kenneth block
800 e campbell rd.
suite 202
richardson, TX 75081
MDR Report Key10834194
MDR Text Key216856331
Report Number9611253-2020-00046
Device Sequence Number1
Product Code EFB
Combination Product (y/n)N
Reporter Country CodeJA
PMA/PMN Number
Number of Events Reported1
Summary Report (Y/N)N
Report Source Manufacturer
Source Type distributor,foreign
Reporter Occupation Non-Healthcare Professional
Type of Report Initial,Followup
Report Date 12/14/2020
1 Device was Involved in the Event
1 Patient was Involved in the Event
Date FDA Received11/13/2020
Is this an Adverse Event Report? No
Is this a Product Problem Report? Yes
Device Operator
Device Model NumberM800WL
Device Catalogue NumberP1265
Was Device Available for Evaluation? Device Returned to Manufacturer
Date Returned to Manufacturer10/26/2020
Is the Reporter a Health Professional?
Was the Report Sent to FDA?
Event Location No Information
Date Manufacturer Received11/17/2020
Was Device Evaluated by Manufacturer? Yes
Date Device Manufactured07/22/2019
Is the Device Single Use? No
Is This a Reprocessed and Reused Single-Use Device? No
Type of Device Usage Reuse

Patient Treatment Data
Date Received: 11/13/2020 Patient Sequence Number: 1