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

Model Number Z95L

Device Problem Detachment of Device or Device Component (2907)

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

Event Date 03/28/2023

Event Type  malfunction  

Manufacturer Narrative

The same adverse event in this report has been reported to the fda separately by the distributor, nsk america corporation, under report number 1422375-2023-00010.

Event Description

On (b)(6) 2023, nakanishi became aware of a malfunction of a nsk handpiece through a complaint input into the complaint database by a distributor (nsk america).Details are as follows: the event occurred on (b)(6) 2023.A dentist was performing a crown preparation procedure on a patient using the z95l handpiece (serial no.(b)(6) ).During the procedure, the bur came out of the handpiece chuck unexpectedly and landed at the back of the patient's throat.The dentist used the suction immediately to prevent the patient from swallowing or aspirating the bur, but at the time of the event the dentist was uncertain if the suction had been successful in capturing the bur before it was swallowed.The dentist sent the patient to the emergency room for a chest x-ray exam to confirm if the bur had been ingested or aspirated and if so, identify the location of the bur.The result of the examination was negative, and the bur was not observed on the images.The dentist checked the suction trap the following day and was able to identify the bur had been captured by the suction during the procedure and the patient had not ingested it.The patient has not reported any need for additional attention or adverse effects since the incident.

Manufacturer Narrative

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 [dbkz0683].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 returned device and observed that the headcap remained depressed in the handpiece (sliding failure).Identification of the specific failure mode(s) and/or mechanism(s) of the associated device components was conducted as follows: a) nakanishi disassembled the handpiece and performed a visual inspection of the internal parts.Nakanishi observed the following: - the headcap was deformed.- the inside of the headcap and the rear side of the cartridge parts were abraded.B) nakanishi took photographs of all the disassembled parts and kept them in the investigation report no.(b)(4).Conclusions reached based on the investigation and analysis results: a) nakanishi identified from the findings in the visual inspection, as well as many years of experience that the cause of the bur separation from the returned handpiece was the opened chuck, which was caused by the headcap remaining depressed during rotation (sliding failure) b) nakanishi also considered the deformed headcap due to impact or drop as a cause of sliding failure.C) misuse by the user led to the above issue, which contributed to the reported event.D) in order to prevent a recurrence of the bur separation , nakanishi took the following actions: d.1) nakanishi reviewed the operation manual and reconfirmed the clarity and understandability of the instructions.D.2) nakanishi will report the above evaluation results to the distributor and directed the distributor to remind 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
• Manufacturer (Section G): NAKANISHI INC.; 700 shimohinata; kanuma-shi, tochigi-ken 322-8 666; JA 322-8666
• Manufacturer Contact: sean kaufman ; 1800 global parkway; hoffman estates, IL 60192 ; 2245128921
• MDR Report Key: 16850598
• MDR Text Key: 314381647
• Report Number: 9611253-2023-00029
• Device Sequence Number: 1
• Product Code: EGS
• Combination Product (y/n): N
• Reporter Country Code: US
• PMA/PMN Number: K182999
• Number of Events Reported: 1
• Summary Report (Y/N): N
• Report Source: Manufacturer
• Source Type: Company Representative,Distributor
• Reporter Occupation: Dentist
• Type of Report: Initial,Followup
• Report Date: 07/27/2023

1 Device was Involved in the Event

1 Patient was Involved in the Event

• Date FDA Received: 05/01/2023
• 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
• Is the Reporter a Health Professional?: Yes
• Date Manufacturer Received: 07/03/2023
• Was Device Evaluated by Manufacturer?: Yes
• Date Device Manufactured: 12/04/2019
• 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
• Patient Age: 78 YR
• Patient Sex: Female
• Patient Weight: 66 KG
• Patient Ethnicity: Non Hispanic
• Patient Race: White