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

Model Number S-MAX M600

Device Problems Use of Device Problem (1670); Device Handling Problem (3265)

Patient Problems Injury (2348); Patient Problem/Medical Problem (2688)

Event Date 02/17/2020

Event Type  Injury  

Manufacturer Narrative

Upon receiving the device involved in the mdr event from the oem, nakanishi conducted a failure analysis of the returned device.These activities are described in more detail below.Methodology used: nakanishi examined the device history record and the repair history for the subject s-max m600 device [serial no.(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 activated the handpiece to perform a simple movement test.Nakanishi observed bur runout, abnormal noise, and unsmooth rotation of the bur.Nakanishi then disassembled the handpiece and performed a visual inspection of the internal parts.Nakanishi confirmed abrasion of the bearing and evidence of contact between the push button and the cartridge.Nakanishi took photographs of all of the disassembled parts and kept them in a file.Conclusions reached based on the investigation and analysis results: nakanishi identified that the cause of the patient's injury was the handpiece overheating due to frictional heat generated by contact between the headcap and the cartridge.This contact was caused by the headcap being pressed during rotation or the patient's buccal mucous membrane being caught between the button and the cap when the push button was depressed.Misuse by the user led to the contact between the headcap and the cartridge, which contributed to the reported injury.In order to prevent a recurrence of the patient's injury, nakanishi took the following actions: nakanishi reviewed the operation manual and reconfirmed clarity and understandability of the instructions.Nakanishi will report the above evaluation results to the oem and direct the oem to remind the user of the importance of using the device as instructed in the operation manual.

Event Description

On (b)(6) 2020, an nsk s-max m600 handpiece was returned to nakanishi from an oem.There was a note with the device about a patient injury caused by the device.The details are as follows.The event occurred on (b)(6) 2020.A dentist was polishing the buccal surface of a premolar of the patient's lower right jaw using the s-max m600 handpiece (serial no.(b)(4)).The patient was not under anesthesia.During the procedure, the dentist noticed blood on the headcap of the device, and found a one-centimeter cut on the mucosa of the patient's right cheek, close to the corner of the mouth.The patient described a sharp pain.The dentist confirmed that the bleeding had stopped, and determined no medical attention was required for the injury.According to the dentist, there were no abnormalities observed in the device prior to use.

• 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: kenneth block ; 800 e campbell rd.; suite 202; richardson, tx ; 4809554
• MDR Report Key: 9864383
• MDR Text Key: 196912199
• Report Number: 9611253-2020-00009
• Device Sequence Number: 1
• Product Code: EFB
• Combination Product (y/n): N
• Reporter Country Code: JA
• PMA/PMN Number: K962543
• Number of Events Reported: 1
• Summary Report (Y/N): N
• Report Source: Manufacturer
• Source Type: foreign,other
• Reporter Occupation: Non-Healthcare Professional
• Type of Report: Initial
• Report Date: 03/23/2020

1 Device was Involved in the Event

1 Patient was Involved in the Event

• Date FDA Received: 03/23/2020
• Is this an Adverse Event Report?: Yes
• Is this a Product Problem Report?: Yes
• Device Operator: Health Professional
• Device Model Number: S-MAX M600
• Device Catalogue Number: P1004
• Was Device Available for Evaluation?: Device Returned to Manufacturer
• Date Returned to Manufacturer: 02/27/2020
• Date Manufacturer Received: 02/27/2020
• Was Device Evaluated by Manufacturer?: Yes
• Date Device Manufactured: 08/11/2009
• 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: 39 YR
• Patient Weight: 70