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

Model Number S-MAX M600L

Device Problems Detachment Of Device Component (1104); Mechanical Problem (1384); Detachment of Device or Device Component (2907)

Patient Problems No Consequences Or Impact To Patient (2199); Foreign Body In Patient (2687); Patient Problem/Medical Problem (2688)

Event Date 06/27/2017

Event Type  malfunction  

Manufacturer Narrative

The dentist did not provide information about the patient's id and weight.

Event Description

On june 29, 2017, an nsk s-max m600l handpiece was returned from a distributor to nakanishi for repair.There was a note with the device stating a bur coming out of the handpiece.The details are as follows.- the event occurred on (b)(6)2017.- a dentist was performing a dental procedure using the s-max m600l handpiece (serial no.: (b)(4)).- during the procedure, the bur suddenly came out and dropped in the patient's mouth.- immediately, the dentist removed the bur from the patient's mouth using tweezers.- the patient was not hurt or injured in the event.

Manufacturer Narrative

Upon receiving the device involved in the mdr event from a distributor, 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 m600l device [serial number (b)(4)].There were no problems observed during the manufacturing or testing noted in the dhr.There were also no repair history records since the device was shipped.Nakanishi measured rotation speed and chuck pull-out force of the returned handpiece.The values nakanishi observed were; rotation speed: 379,000min-1 (company criteria: 360,000-430,000min-1).Chuck pull-out force: 12.7n (company criteria: 14.7-39.2n).The value of the chuck pull-out force did not meet the criteria.Nakanishi tried cutting melamine using a new carbide bur attached to the handpiece to see whether or not the bur would come off.The reason for the new bur being used in the cutting test was because the bur involved in the event was not returned from the distributor.Nakanishi observed bur coming off in the evaluation.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 dirt on inside the headcap, on the bur holder and on the bur pusher retainers.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 bur coming off was ingress of dirt into the bur shank reduced the bur retention force, which led to the reported phenomena.A lack of maintenance could contribute to a bur coming off from the subject device.In order to prevent a recurrence of the bur coming off, 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, 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 ; 1201 richardson dr.; suite 160; richardson, TX 75080 ; 9724809554
• MDR Report Key: 6740515
• MDR Text Key: 82050961
• Report Number: 9611253-2017-00036
• 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: distributor,foreign
• Reporter Occupation: Other
• Type of Report: Initial,Followup
• Report Date: 08/03/2017

1 Device was Involved in the Event

1 Patient was Involved in the Event

• Date FDA Received: 07/25/2017
• Is this an Adverse Event Report?: No
• Is this a Product Problem Report?: Yes
• Device Operator: Dentist
• Device Model Number: S-MAX M600L
• Device Catalogue Number: P1002
• Was Device Available for Evaluation?: Device Returned to Manufacturer
• Date Returned to Manufacturer: 06/29/2017
• Is the Reporter a Health Professional?: No
• Was the Report Sent to FDA?: No
• Date Manufacturer Received: 07/06/2017
• Was Device Evaluated by Manufacturer?: Yes
• Date Device Manufactured: 02/28/2011
• 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: 50 YR