MAUDE Adverse Event Report: NAKANISHI INC. NSK; HANDPIECE, CONTRA- AND RIGHT-ANGLE ATTACHMENT, DENTAL

Model Number Z95L

Device Problems Break (1069); Unintended Movement (3026)

Patient Problems Laceration(s) (1946); Tooth Fracture (2428); Skin Tears (2516)

Event Date 10/15/2020

Event Type  Injury  

Manufacturer Narrative

The dentist refused to provide the patient id and weight.

Event Description

On (b)(6) 2020, nakanishi received a phone call from a dealer about a patient injury caused by an nsk handpiece.Upon receipt of the information, nakanishi visited the dental office for further information about the event.The details nakanishi obtained from the communication are as follows: the event occurred on (b)(6) 2020.The dentist was performing an aesthetic dental procedure on a patient using the z95l handpiece.During the procedure, the mani bur attached to the device run out of control, broke the patient's upper left tooth, and cut the patient's lip.The wound required a few stitches to be closed.The dentist could not identify which one of the two suspect devices actually caused the above event.Therefore, nakanishi is submitting two separate mdrs for this event based on the information from the dentist.This mdr is regarding the handpiece with the serial number (b)(4).

Event Description

On november 13, 2020, nakanishi received detailed information on the event from the dentist.At the time of the event, the dentist was grooving the labial surface of #1 of the patient's upper right jaw.During the procedure, the bur rotated off-center and caused the event.

Manufacturer Narrative

Upon receiving the device involved in the mdr event, nakanishi conducted a failure analysis of the returned device [report no.(b)(4)].These activities are described in more detail below.Methodology used: a) nakanishi examined the device history record and the repair history for the subject z95l device [serial no.(b)(6)].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.B) since the mani bur used with the handpiece at the time of event was not returned, nakanishi attached a test bur to the device and observed rotational resistance, pull-out strength, and whether or not the bur would rotate off-center.Nakanishi did not observe any abnormality during the evaluation.Conclusions reached based on the investigation and analysis results: a) although nakanishi could not replicate the reported phenomena, nakanishi identified the cause of the patient's injury from the device usage at the time of the event nakanishi heard from the dentist; that use of the out-of-specification bur (mani bur) increased the probability of off-center rotation leading to the bur coming off, which have resulted in the patient's injury.B) misuse by the user contributed to the bur separation, leading to the reported injury.C) in order to prevent a recurrence of the patient's injury, nakanishi took the following actions: c.1) nakanishi reviewed the operation manual and reconfirmed the clarity and understandability of the instructions.C.2) nakanishi reported the above evaluation results to the dentist and reminded the dentist of the importance of using the device as instructed in the operation manual.

• Brand Name: NSK
• Type of Device: HANDPIECE, CONTRA- AND RIGHT-ANGLE ATTACHMENT, DENTAL
• Manufacturer (Section D): NAKANISHI INC.; 700 shimohinata; kanuma-shi, tochigi-ken 322-8 666; JA 322-8666
• MDR Report Key: 10820982
• MDR Text Key: 216311656
• Report Number: 9611253-2020-00043
• Device Sequence Number: 1
• Product Code: EGS
• Combination Product (y/n): N
• PMA/PMN Number: K182999
• Number of Events Reported: 1
• Summary Report (Y/N): N
• Report Source: Manufacturer
• Source Type: foreign,other
• Type of Report: Initial,Followup,Followup
• Report Date: 01/12/2021

1 Device was Involved in the Event

1 Patient was Involved in the Event

• Date FDA Received: 11/11/2020
• Is this an Adverse Event Report?: Yes
• Is this a Product Problem Report?: Yes
• Device Operator: Health Professional
• Device Model Number: Z95L
• Device Catalogue Number: C1034
• Was Device Available for Evaluation?: Device Returned to Manufacturer
• Date Returned to Manufacturer: 12/07/2020
• Date Manufacturer Received: 12/17/2020
• Is This a Reprocessed and Reused Single-Use Device?: No
• Patient Sequence Number: 1
• Patient Outcome(s): Other
• Patient Age: 20 YR