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

Model Number X-SG65L

Device Problems Overheating of Device (1437); Temperature Problem (3022); Noise, Audible (3273)

Patient Problems Burn(s) (1757); Injury (2348); Patient Problem/Medical Problem (2688); Partial thickness (Second Degree) Burn (2694)

Event Date 01/13/2017

Event Type  Injury  

Manufacturer Narrative

Nakanishi tried to obtain the patient's weight, but the dentist refused to provide it.

Event Description

On february 1, 2017, nakanishi received a phone call from a distributor about a handpiece overheating.Details are as follows.The event occurred on (b)(6) 2017.A dentist was performing an alveolectomy on a patient for extraction of the lower right tooth #8 using the nsk handpiece, x-sg65l (serial no.: (b)(4)).The patient was under general anesthesia.The dentist was made aware of a white blister on the right side of the patient's lower lip.There were abnormal noises from the handpiece during rotation.The dentist provided the patient with a steroid ointment and a pain reliever.The patient is receiving follow-up observations and showing a smooth recovery.The dentist will continue with the follow-ups and may consider a medical intervention (plastic surgical procedure) to be necessary depending on the situation.

Manufacturer Narrative

Upon receiving the device involved in the mdr event, nakanishi conducted a failure analysis of the returned device that included measuring the temperature of the operating device [c170201-07-1].These activities are described in more detail below.Methodology used: nakanishi examined the device history record and the repair history for the subject x-sg65l device [serial number (b)(4)].There were no problems observed during the manufacturing or testing noted in the dhr.The repair history showed 2 service records (september 2015 and june 2016) since the device was shipped.According to the service record, after repairing the handpiece (replacement of components), nakanishi performed all of the necessary operation checks.Nakanishi confirmed that all of the criteria were met.Nakanishi tried to rotate the handpiece's motor to conduct temperature testing, however, the motor did not rotate at all.Therefore, nakanishi was not able to measure the temperature rise of the returned device.Identification of the specific failure mode(s) and/or mechanism(s) and the associated device components involved: nakanishi disassembled the handpiece and performed a visual inspection of the inside parts.Nakanishi observed the following phenomena: - dirt and corrosion inside parts - dirt and breakage of the bearing (ball retaining part) incorporated in the tip of the handpiece 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 overheating of the returned device was abnormal resistance during rotation caused by the broken bearings due to the ingress of dirt into the bearing.Nakanishi also heard from the dentist about the maintenance the dentist regularly did, which indicates failures the dentist made in their maintenance method.A lack of maintenance causes the accumulation of dirt in the inside parts, which causes dirt ingress into the bearing during rotation, leading to the broken bearings.This contributes to the handpiece overheating.In order to prevent a recurrence of the handpiece overheating, nakanishi took the following actions: nakanishi reviewed the operation manual and reconfirmed clarity and understandability of the instructions.Nakanishi reported the above evaluation results to the dentist and reminded the dentist 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: kenneth block ; 1201 richardson dr.; suite 160; richardson, TX 75080 ; 9724809554
• MDR Report Key: 6352776
• MDR Text Key: 68129888
• Report Number: 9611253-2017-00011
• Device Sequence Number: 1
• Product Code: KMW
• Combination Product (y/n): N
• Reporter Country Code: JA
• PMA/PMN Number: K970953
• Number of Events Reported: 1
• Summary Report (Y/N): N
• Report Source: Manufacturer
• Source Type: distributor,foreign
• Reporter Occupation: Other
• Type of Report: Initial,Followup
• Report Date: 06/06/2017

1 Device was Involved in the Event

1 Patient was Involved in the Event

• Date FDA Received: 02/23/2017
• Is this an Adverse Event Report?: Yes
• Is this a Product Problem Report?: No
• Device Operator: Dentist
• Device Model Number: X-SG65L
• Device Catalogue Number: H1009
• Was Device Available for Evaluation?: Device Returned to Manufacturer
• Date Returned to Manufacturer: 02/02/2017
• Is the Reporter a Health Professional?: No
• Date Manufacturer Received: 02/10/2017
• Was Device Evaluated by Manufacturer?: Yes
• Date Device Manufactured: 05/30/2014
• 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