MAUDE Adverse Event Report: NAKANISHI INC. NSK; HANDPIECE, AIR-POWERED, DENTAL

Model Number Z-ML

Device Problems Break (1069); Detachment Of Device Component (1104); Mechanical Problem (1384); Detachment of Device or Device Component (2907)

Patient Problems Tissue Damage (2104); Injury (2348); Patient Problem/Medical Problem (2688)

Event Date 07/19/2017

Event Type  Injury  

Manufacturer Narrative

The dentist did not disclose any information about the patient.This event occurred in (b)(6), but similar products are marketed in the us under k113655.

Event Description

On july 26, 2017, nakanishi received an e-mail from a distributor about a patient's injury with an nsk handpiece.Details are as follows.The event occurred on (b)(6) 2017.A dentist was cutting the patient's tooth using the handpiece, z-ml (serial no.(b)(4)).During the procedure, the handpiece head suddenly came off and damaged mucous membrane in the oral cavity.The dentist found a little bleeding from a minor cut in the patient's mouth and provided a hemostatic treatment to the patient.The dentist determined no other treatment for the cut was necessary.According to the dentist, there were no abnormalities or malfunctions observed with the handpiece prior to use.

Manufacturer Narrative

Upon receiving the device involved in the mdr event from a distributor, nakanishi conducted a failure analysis of the returned device [(b)(4)].These activities are described in more detail below.Methodology used: nakanishi examined the device history record and the repair history for the subject z-ml 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 performed a manual reproducibility test.There was no problem with how to connect the handpiece with the coupling.Nakanishi then pulled the handpiece by hand from the coupling without pulling the connector ring of the coupling or without releasing the lock to see whether or not the handpiece was removed from the coupling.Nakanishi did not observe the handpiece coming off as reported by the user.Nakanishi supplied the handpiece with air with the manufacturer's recommended pressure (0.28mpa) and stopped supplying repeatedly (100 times) to replicate the reported phenomenon.Separation of the handpiece from the coupling was not observed during the test.Nakanishi conducted the same test with the maximum pressure air (0.3mpa), but no coming off was observed.Nakanishi evaluated pull strength of the handpiece by pulling the handpiece from the coupling using force specified in the specifications (100n) or greater.The handpiece did not separate from the coupling.Conclusions reached based on the investigation and analysis results: nakanishi could not identify the exact cause of the handpiece separating from the coupling because nakanishi was not able to replicate the phenomenon during testing and did not observe any abnormalities in the visual inspection.In spite of the fact that nakanishi did not identify the cause, nakanishi considers the possibility from many years of experience that the cause of the handpiece separation from the coupling was that the connector ring of the coupling was accidentally pulled in the lock release direction by external factors.Carelessness by the user causes erroneous operation leading to the report handpiece coming off.In order to prevent a recurrence of the handpiece separating from the coupling, nakanishi reported the above evaluation results to the dentist and urged the dentist to exercise caution in use of the device.

• Brand Name: NSK
• Type of Device: HANDPIECE, AIR-POWERED, DENTAL
• Manufacturer (Section D): NAKANISHI INC.; 700 shimohinata; kanuma-shi, tochigi-ken 322-8 666; JA 322-8666
• Manufacturer (Section G): NAKANISHI INC.; 700 shimohinata; kanuma-shi, tochigi-ken 322-8 666; JA 322-8666
• Manufacturer Contact: kenneth block ; 1201 richardson dr.; suite 160; richardson, TX 75080 ; 9724809554
• MDR Report Key: 6768506
• MDR Text Key: 81899638
• Report Number: 9611253-2017-00038
• Device Sequence Number: 1
• Product Code: EFB
• Combination Product (y/n): N
• Reporter Country Code: JA
• Number of Events Reported: 1
• Summary Report (Y/N): N
• Report Source: Manufacturer
• Source Type: distributor,foreign
• Reporter Occupation: Other
• Type of Report: Initial,Followup
• Report Date: 09/12/2017

1 Device was Involved in the Event

1 Patient was Involved in the Event

• Is this an Adverse Event Report?: Yes
• Is this a Product Problem Report?: No
• Device Operator: Dentist
• Device Model Number: Z-ML
• Device Catalogue Number: P1110003
• Was Device Available for Evaluation?: Yes
• Is the Reporter a Health Professional?: No
• Was the Report Sent to FDA?: No
• Initial Date Manufacturer Received: 07/26/2017
• Initial Date FDA Received: 08/04/2017
• Supplement Dates Manufacturer Received: 08/11/2017
• Supplement Dates FDA Received: 09/12/2017
• Was Device Evaluated by Manufacturer?: Yes
• Date Device Manufactured: 06/30/2016
• Is the Device Single Use?: No
• Is This a Reprocessed and Reused Single-Use Device?: No
• Type of Device Usage: Reuse
• Patient Sequence Number: 1
• Patient Outcome(s): Other