MAUDE Adverse Event Report: NAKANISHI INC. MASTER II MINI PUSH BUTTON; HANDPIECE, AIR-POWERED, DENTAL

Model Number MASTER II MINI PUSH BUTTON

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); No Known Impact Or Consequence To Patient (2692)

Event Date 10/25/2016

Event Type  malfunction  

Manufacturer Narrative

Despite the following efforts (b)(4) made, (b)(4) was not able to obtain any further information, including patient information.On (b)(4) 2016, (b)(4) made a phone call to the dental office for information and left a message.On the afternoon of the same day, (b)(4) tried contacting the office again, and no one answered the call.(b)(4) left another message.On (b)(6) 2016, (b)(4) spoke with the staff from the dental office, but the staff did not provide any patient information.

Event Description

On (b)(6) 2016, nakanishi received an e-mail from (b)(4) about a device manufactured by nakanishi for (b)(4).The information nakanishi received in the e-mail is: the event occurred on (b)(6) 2016.A dentist was drilling off the cement on the patient's tooth using a master ii mini push button.The bur manufactured by midwest suddenly became loose from the chuck and fell off in the patient's mouth.The patient was not injured by the malfunction.

Manufacturer Narrative

Upon receiving the device involved in the mdr event from a distributor, nakanishi conducted a failure analysis of the returned device [c161116-01-1].These activities are described in more detail below.Methodology used: nakanishi examined the device history record and the repair history for the subject master ii mini push button 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 the bur retention force with a dia.1.598mm test bur.The value nakanishi observed was 15.8n, which meets the company criteria (14.7n or greater).Nakanishi tried cutting a copper plate and melamine using a new bur attached to the returned 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 did not observe any bur coming off in the evaluation nakanishi disassembled the handpiece cartridge and performed a visual inspection of the chuck.There were no abnormalities such as abrasion or dirt observed that may have caused the reported bur slippage on the bur holding parts.Nakanishi took photographs of all of the disassembled parts and kept them in a file.Conclusions reached based on the investigation and analysis results: although nakanishi could not replicate the reported event, nakanishi considers the following as possible causes, based on phenomena nsk has experienced in the past.- use of a bur with the diameter (of the chuck-connecting side) smaller than the one specified in the international standard (dia.1.590mm-1.600mm) reduced bur retention force, which led to the bur coming off.- use of a bur with the diameter (of the cutting side) larger than the one specified in the international standard (dia.2.0mm or greater) applied load exceeding the bur retention force to the chuck, which led to the bur coming off.- ingress of dirt into the bur shank reduced the bur retention force, which led to the bur coming off.- cutting under high load applied load exceeding the bur retention force to the chuck, which caused bur slip leading to the bur coming off.Failure to follow the instructions regarding burs available for use with the handpiece, or a lack of maintenance, could contribute to a bur coming off as reported above.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 (b)(4) and directed (b)(4) to remind the user of the importance of following instructions in the operation manual.

• Brand Name: MASTER II MINI PUSH BUTTON
• 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: 6152196
• MDR Text Key: 62377364
• Report Number: 9611253-2016-00068
• Device Sequence Number: 1
• Product Code: EFB
• Combination Product (y/n): N
• Reporter Country Code: US
• PMA/PMN Number: K962543
• Number of Events Reported: 1
• Summary Report (Y/N): N
• Report Source: Manufacturer
• Source Type: distributor
• Reporter Occupation: Other
• Type of Report: Initial,Followup
• Report Date: 03/27/2017

1 Device was Involved in the Event

1 Patient was Involved in the Event

• Is this an Adverse Event Report?: No
• Is this a Product Problem Report?: Yes
• Device Operator: Dentist
• Device Model Number: MASTER II MINI PUSH BUTTON
• Device Catalogue Number: 9004613
• Was Device Available for Evaluation?: No
• Is the Reporter a Health Professional?: No
• Initial Date Manufacturer Received: 11/15/2016
• Initial Date FDA Received: 12/07/2016
• Supplement Dates Manufacturer Received: Not provided
• Supplement Dates FDA Received: 03/27/2017
• Was Device Evaluated by Manufacturer?: Device Not Returned to Manufacturer
• Date Device Manufactured: 09/15/2016
• Is the Device Single Use?: No
• Is This a Reprocessed and Reused Single-Use Device?: No
• Type of Device Usage: Initial
• Patient Sequence Number: 1
• Patient Outcome(s): Other