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

Model Number Z95L

Device Problems Detachment of Device or Device Component (2907); Device Fell (4014)

Patient Problem No Clinical Signs, Symptoms or Conditions (4582)

Event Date 06/16/2021

Event Type  malfunction  

Manufacturer Narrative

Nakanishi is trying to obtain further information about the event, including information about the patient.

Event Description

On june 17, 2021, nakanishi received a phone call from a distributor about a malfunction of an nsk handpiece.Details are as follows.The event occurred on (b)(6) 2021.The doctor was removing a crown from the patient's tooth using the z95l device (serial no.(b)(4)).During the procedure, the push button suddenly separated from the handpiece and fell into the patient's mouth.The dentist immediately retrieved the push button, and there was no effect on the patient.

Manufacturer Narrative

On june 15, 2021, nakanishi visited the dental office and the dentist refused to provide information about the patient's age and weight.Upon receiving the device involved in the mdr event from the distributor, 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.Dbkx1082].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) nakanishi conducted a visual inspection of the device that was already disassembled when returned.Nakanishi observed the following: the force fit ring came out of the push button.There was evidence of contact with the push button and the cartridge during rotation.C) nakanishi measured the size of the push button, force fit ring, and spring and observed that the sizes were within the specifications.D) 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: a) nakanishi identified the cause of the push button separation based on the findings in the visual inspection, which was that the force fit ring fixing the push button to the headcap had come off.Nakanishi considers the possibility from many years of experience and based on the evidence of contact observed, that the force fit ring coming off was caused by the headcap being pressed down during rotation.B) misuse by the user led to the above issue, which contributed to the reported event.C) in order to prevent a recurrence of the headcap separation, nakanishi took the following actions: c.1) nakanishi reviewed the operation manual and reconfirmed clarity and understandability of the instructions.C.2) nakanishi reported the above evaluation results to the user and reminded the user 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: 12125868
• MDR Text Key: 267230018
• Report Number: 9611253-2021-00038
• 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: distributor,foreign
• Type of Report: Initial,Followup
• Report Date: 07/21/2021

1 Device was Involved in the Event

1 Patient was Involved in the Event

• Date FDA Received: 07/06/2021
• Is this an Adverse Event Report?: No
• 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: 06/22/2021
• Date Manufacturer Received: 07/05/2021
• Is This a Reprocessed and Reused Single-Use Device?: No
• Patient Sequence Number: 1
• Patient Outcome(s): Other