MAUDE Adverse Event Report: NAKANISHI INC. NSK; HANDPIECE, ROTARY BONE CUTTING

Model Number SGS-E2S

Device Problem Overheating of Device (1437)

Patient Problem Burn(s) (1757)

Event Date 11/14/2022

Event Type  Injury  

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 (b)(4).

Event Description

On (b)(6) 2022, nakanishi became aware of a handpiece overheating through a complaint input into the complaint database by a distributor (nsk america).Details are as follows: the event occurred on (b)(6) 2022.The dentist was performing a surgical extraction on a patient using the sgs-e2s handpiece (serial no.Abk20007).During the procedure, the device overheated and the patient received a minor burn injury to their lip.No medical treatment was required at the time of the event.The patient is reported to have healed normally without any need for further treatment.

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.C221208-01].These activities are described in more detail below.Methodology used: a) nakanishi examined the device history record and the repair history for the subject sgs-e2s device [abk20007].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 connected the handpiece to the motor and tried to rotate the motor.However, the handpiece was locked, and the motor did not rotate at all.Therefore, nakanishi was not able to conduct temperature testing of the device.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 that the gear shaft was soiled, discolored, and broken.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 could not replicate the temperature increase from the event, but based on the findings in the visual inspection, nakanishi identified that the cause of the handpiece overheating was abnormal resistance during rotation due to the broken gear shaft.B) nakanishi considers the possibility from many years of experience that the cause of the broken gear shaft was the ingress of undesirable materials into the bearing, leading to abrasion.C) a lack of maintenance caused the accumulation of debris on the internal parts, which contributed to the handpiece overheating.D) in order to prevent a recurrence of the handpiece overheating, nakanishi took the following actions: d.1) nakanishi reviewed the operation manual and reconfirmed the clarity and understandability of the instructions.D.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.

• Brand Name: NSK
• Type of Device: HANDPIECE, ROTARY BONE CUTTING
• 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 60192 ; 2245128921
• MDR Report Key: 16030504
• MDR Text Key: 305976900
• Report Number: 9611253-2022-00088
• Device Sequence Number: 1
• Product Code: KMW
• Combination Product (y/n): N
• Reporter Country Code: US
• PMA/PMN Number: K171155
• Number of Events Reported: 1
• Summary Report (Y/N): N
• Report Source: Manufacturer
• Source Type: Company Representative,Distributor
• Reporter Occupation: Administrator/Supervisor
• Remedial Action: Recall
• Type of Report: Initial,Followup
• Report Date: 03/14/2023

1 Device was Involved in the Event

1 Patient was Involved in the Event

• Date FDA Received: 12/21/2022
• Is this an Adverse Event Report?: Yes
• Is this a Product Problem Report?: Yes
• Device Operator: Health Professional
• Device Model Number: SGS-E2S
• Device Catalogue Number: H266
• Was Device Available for Evaluation?: Device Returned to Manufacturer
• Date Returned to Manufacturer: 12/16/2022
• Date Manufacturer Received: 02/15/2023
• Was Device Evaluated by Manufacturer?: Yes
• Date Device Manufactured: 02/15/2019
• Is the Device Single Use?: No
• Is This a Reprocessed and Reused Single-Use Device?: No
• Type of Device Usage: Reuse
• Removal/Correction Number: 9611253-060818-001-R
• Patient Sequence Number: 1
• Patient Outcome(s): Other
• Patient Age: 81 YR
• Patient Sex: Male
• Patient Weight: 82 KG
• Patient Ethnicity: Non Hispanic
• Patient Race: White