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

Model Number Z900L

Device Problems Detachment Of Device Component (1104); Mechanical Problem (1384); Device Slipped (1584); 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); No Code Available (3191)

Event Date 10/20/2017

Event Type  malfunction  

Manufacturer Narrative

Nakanishi is scheduled to visit the dental office to obtain information about the patient and details of the event.

Event Description

On (b)(6) 2017, an nsk z900l handpiece was returned from a dealer 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 z900l handpiece (serial no.: (b)(4)).- during the procedure, the bur suddenly came out of the handpiece and the patient swallowed the bur.

Manufacturer Narrative

In the communication with the dealer on december 15, 2017, the dealer confirmed with the dentists that the bur was not swallowed by the patient, but did not provide the patient identifier and weight, because the dentist refused to disclose the information.

Event Description

On december 15, 2017, nakanishi made a phone call to the dealer and obtained detailed information on the event.The procedure the dentist was performing at the time of the event was a caries removal.The patient was not under anesthesia.No abnormality or malfunction was observed with the device prior to the event.During the procedure, the bur suddenly slipped and dropped in the patient's mouth.The dentist retrieved the bur from the patient's mouth and determined that no medical intervention was necessary.

Manufacturer Narrative

Nakanishi is still trying to obtain information about the patient and details of the event.Upon receiving the device involved in the mdr event from a dealer, nakanishi conducted a failure analysis of the returned device [c171027-06].These activities are described in more detail below.Methodology used: nakanishi examined the device history record and the repair history for the subject z900l 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 12.7n, which falls below the company criteria (25n or greater).Nakanishi tried rotating the handpiece with the air supply pressure of 0.28mpa.The bur came out of the handpiece and made an abnormal noise.Nakanishi disassembled the handpiece cartridge and performed a visual inspection of the chuck.Nakanishi observed an accumulation of debris on the bur holding surface.When cleaning the debris off the bur holding surface, it was noted that there was abrasion on the surface.Nakanishi took photographs of all of the disassembled parts and kept them in the investigation report #(b)(4).Conclusions reached based on the investigation and analysis results: nakanishi identified that the cause of the reported bur coming out was bur slip caused by insufficient bur retention force due to the accumulation of debris and abrasion on the bur holding surface.A lack of maintenance causes the above phenomena, which leads to the bur coming out.In order to prevent a recurrence of the bur coming out, 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 ; 800 e campbell rd.; suite 202; richardson, TX 75081 ; 9724809554
• MDR Report Key: 7036324
• MDR Text Key: 92165951
• Report Number: 9611253-2017-00063
• Device Sequence Number: 1
• Product Code: EFB
• Combination Product (y/n): N
• Reporter Country Code: JA
• PMA/PMN Number: K113655
• Number of Events Reported: 1
• Summary Report (Y/N): N
• Report Source: Manufacturer
• Source Type: foreign,other
• Reporter Occupation: Other
• Type of Report: Initial,Followup,Followup
• Report Date: 01/06/2018

1 Device was Involved in the Event

1 Patient was Involved in the Event

• Date FDA Received: 11/16/2017
• Is this an Adverse Event Report?: Yes
• Is this a Product Problem Report?: Yes
• Device Operator: Dentist
• Device Model Number: Z900L
• Device Catalogue Number: P1111
• Was Device Available for Evaluation?: Device Returned to Manufacturer
• Date Returned to Manufacturer: 10/27/2017
• Is the Reporter a Health Professional?: No
• Was the Report Sent to FDA?: No
• Date Manufacturer Received: 12/15/2017
• Was Device Evaluated by Manufacturer?: Yes
• Date Device Manufactured: 09/30/2015
• 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: 40 YR