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

Model Number Z95L

Device Problem Device Handling Problem (3265)

Patient Problem Laceration(s) (1946)

Event Date 07/30/2022

Event Type  Injury  

Manufacturer Narrative

The dentist refused to provide any information about the patient.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 [(b)(4)].There were no problems observed during manufacturing or testing noted in the dhr.There were no repair history records since the device was shipped.B) nakanishi conducted a preliminary visual inspection of the headcap of the returned device.There were no visible abnormalities, such as damage or deformation on the head.C) nakanishi measured the size of the bur used at the time of the event.The maximum diameter of the working portion was 2.194mm in the measurement, which is out of the device specification (2.00mm).D) nakanishi disassembled the handpiece and performed as additional visual inspection of the inside parts.Nakanishi observed the following phenomena: there was an evidence of contact between the push button and the cartridge.There was debris on the cartridge and inside of the headcap.E) 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 that the cause of the reported patient's injury, based on what nakanishi observed in the visual inspection, was the patient's oral mucosa being caught between the push button and the headcap when the push button was pressed.B) misuse by the user led to the contact between the headcap and the cartridge, which contributed 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 distributor and directed the distributor to remind the user of the importance of maintenance as instructed in the operation manual.

Event Description

On august 8, 2022, a nsk z95l handpiece was returned from a distributor to nakanishi for repair.There was a note with the device stating that the device had injured a patient.Upon receipt of the information, nakanishi made a phone call to the dental office for further information about the event including information about the patient.The details nakanishi obtained are as follows.The event occurred on (b)(6) 2022.The dentist was preparing an abutment tooth of the patient's upper left jaw using the z95l handpiece (serial no.(b)(4)).During the procedure, the headcap of the handpiece came in contact with the patient's cheek.The dentist found a bleeding wound on the oral mucosa of the patient's cheek.The patient was not under anesthesia.The dentist determined that no medical intervention was necessary.

• 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: 15308445
• MDR Text Key: 298774702
• Report Number: 9611253-2022-00057
• 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
• Report Date: 08/29/2022

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: Z95L
• Device Catalogue Number: C1034
• Was Device Available for Evaluation?: Device Returned to Manufacturer
• Date Returned to Manufacturer: 08/08/2022
• Initial Date Manufacturer Received: 08/08/2022
• Initial Date FDA Received: 08/29/2022
• Was Device Evaluated by Manufacturer?: Yes
• Date Device Manufactured: 11/25/2022
• 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