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

Model Number X95

Device Problem Detachment of Device or Device Component (2907)

Patient Problem Foreign Body In Patient (2687)

Event Date 06/17/2021

Event Type  Injury  

Manufacturer Narrative

Nakanishi is still trying to obtain detailed information about the event, including information about the patient.Upon receiving the device involved in the mdr event from the distributor, nakanishi conducted a failure analysis of the returned device [report (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 x95 device [(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 measured the bur retention force and observed 17.0n, which is below the device specification (22.0n or greater).Identification of the specific failure mode(s) and/or mechanism(s) of the associated device components was conducted as follows: nakanishi disassembled the handpiece and performed a visual inspection of the internal parts.Nakanishi observed the following: the bur holding part of the chuck was abraded and soiled.There was evidence of contact between the headcap and cartridge pusher.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 identified that the cause of the bur separation from the handpiece was a decrease in bur retention force due to the accumulation of debris on the chuck and abrasion of the chuck.Nakanishi considers the possibility from many years of experience that the cause of the prematurely abraded chuck was the bur spinning around in the chuck due to cutting with force exceeding the retention force device specification, which accelerated abrasion of the chuck.A lack of maintenance caused the accumulation of debris on the internal parts, which contributed to the reported bur separation.In order to prevent a recurrence of the bur separation, nakanishi took the following actions: nakanishi reviewed the operation manual and reconfirmed the clarity and understandability of the instructions.Nakanishi reported the above evaluation results to the dentist, and reminded the dentist of the importance of maintenance and checking of the handpiece prior to use to prevent overheating, as instructed in the operation manual.

Event Description

On (b)(6) 2021, an nsk x95 handpiece was returned from a distributor to nakanishi for repair.There was a note with the device stating that the device had malfunctioned.The details are as follows: the event occurred on (b)(6) 2021.A dentist was performing a dental procedure using the x95 handpiece (serial (b)(4)).During the procedure, the bur suddenly separated from the handpiece and fell into the patient's mouth.

Manufacturer Narrative

No detailed information about the event, including information about the patient, was provided despite the repeated attempts as follows.- (b)(6) 2021, nakanishi made a phone call to the dentist, but the dentist was not available.- (b)(6) 2021, nakanishi visited the dental office to obtain information but did not receive any information.- (b)(6) 2021, nakanishi made another phone call to the dentist, but the dentist refused to disclose any information.

• 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
• Manufacturer (Section G): NAKANISHI INC.; 700 shimohina; kanuma-shi, tochigi-ken 322-8 666; JA 322-8666
• Manufacturer Contact: kenneth block ; 800 e campbell rd.; suite 202; richardson, TX 75081 ; 9724809554
• MDR Report Key: 12170896
• MDR Text Key: 266948754
• Report Number: 9611253-2021-00040
• Device Sequence Number: 1
• Product Code: EGS
• Combination Product (y/n): N
• Reporter Country Code: JA
• PMA/PMN Number: K182999
• Number of Events Reported: 1
• Summary Report (Y/N): N
• Report Source: Manufacturer
• Source Type: Foreign,Distributor
• Reporter Occupation: Non-Healthcare Professional
• Type of Report: Initial,Followup
• Report Date: 11/30/2021

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?: Yes
• Device Operator: Health Professional
• Device Model Number: X95
• Device Catalogue Number: C610
• Was Device Available for Evaluation?: Device Returned to Manufacturer
• Date Returned to Manufacturer: 06/24/2021
• Initial Date Manufacturer Received: 06/24/2021
• Initial Date FDA Received: 07/14/2021
• Supplement Dates Manufacturer Received: 11/10/2021
• Supplement Dates FDA Received: 11/29/2021
• Was Device Evaluated by Manufacturer?: Yes
• Date Device Manufactured: 01/31/2019
• 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