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

Model Number Z900KL

Device Problem Detachment of Device or Device Component (2907)

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

Event Date 01/06/2023

Event Type  malfunction  

Event Description

On january 19, 2023, nakanishi became aware of a malfunction of a nsk handpiece through a complaint input into the complaint database by a distributor ((b)(4)).According to the distributor, there are two devices suspected to be involved in the event, but the dental office could not identify which one of the devices actually caused the following event.Therefore, nakanishi is submitting two separate mdrs for this event.This mdr is regarding the handpiece with the serial number (b)(4).Details are as follows: the event occurred around (b)(6) 2023.(the exact date is unknown.).A dentist was performing a dental procedure on a patient's tooth using the z900kl.Handpiece (serial no.(b)(4)).During the procedure, the bur was released from the handpiece and landed at the back of the patient's throat.The bur was recovered by the dentist and the patient was not injured in the event.

Manufacturer Narrative

The same adverse event in this report has been reported to the fda separately by the distributor, (b)(4), under report number 1422375-2023-00002.

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 z900kl device [0bj80327].There were no problems observed during manufacturing or testing noted in the dhr.There were no records indicating nakanishi (the manufacturer) repaired the device since the device was shipped.Nakanishi received the repair record from nsk america (the distributor), which included the detailed information about the repair nsk america carried out.Nakanishi kept the repair record in a file.B) nakanishi conducted a visual inspection of the returned device and observed that the holding portion of the broken bur was left behind in the handpiece.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 bearing of the cartridge were soiled and corroded.- the bur-holding part of the chuck was slightly abraded.B) nakanishi measured the size of the broken bur attached in the handpiece.The length of the chucking portion was 8.00mm in the measurement, which is out of the device specification (12.00mm).C) nakanishi took photographs of all the internal 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 visual inspection that the cause of the reported event was that the bur had been broken during cutting and landed in the patient's mouth.Nakanishi considers the possibility from many years of experience that the cause of the broken bur was increase of the cutting vibration due to the combination of the use of the out-of-specification bur, accumulation of debris on the bearing and the high-load cutting.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 broken bur , nakanishi took the following actions: c.1) nakanishi reviewed the operation manual and reconfirmed the clarity and understandability of the instructions.C.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, 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: sean kaufman ; 1800 global parkway; hoffman estates, IL 60192 ; 2245128921
• MDR Report Key: 16359901
• MDR Text Key: 309607361
• Report Number: 9611253-2023-00009
• Device Sequence Number: 1
• Product Code: EFB
• Combination Product (y/n): N
• Reporter Country Code: US
• PMA/PMN Number: K113655
• Number of Events Reported: 1
• Summary Report (Y/N): N
• Report Source: Manufacturer
• Source Type: Company Representative,Distributor
• Reporter Occupation: Physician Assistant
• Type of Report: Initial,Followup
• Report Date: 04/17/2023

1 Device was Involved in the Event

1 Patient was Involved in the Event

• Is this an Adverse Event Report?: No
• Is this a Product Problem Report?: Yes
• Device Operator: Health Professional
• Device Model Number: Z900KL
• Device Catalogue Number: P1113
• Was Device Available for Evaluation?: Device Returned to Manufacturer
• Date Returned to Manufacturer: 01/30/2023
• Is the Reporter a Health Professional?: Yes
• Initial Date Manufacturer Received: 01/19/2023
• Initial Date FDA Received: 02/12/2023
• Supplement Dates Manufacturer Received: 03/24/2023
• Supplement Dates FDA Received: 04/16/2023
• Was Device Evaluated by Manufacturer?: Yes
• Date Device Manufactured: 08/24/2018
• 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