MAUDE Adverse Event Report: NAKANISHI INC. NSK; SCALER, ULTRASONIC

Model Number H-SG1

Device Problems Break (1069); Fracture (1260); Material Integrity Problem (2978)

Patient Problems No Patient Involvement (2645); No Known Impact Or Consequence To Patient (2692)

Event Date 08/03/2016

Event Type  malfunction  

Manufacturer Narrative

As of september 5, 2016, nakanishi has not received information about patient's weight.Nakanishi will ask for the information at the next contact.This event occurred in (b)(6), but similar products are marketed in the us under k073678.

Event Description

On august 19, 2016, an nsk variosurg3 tip, h-sg1 (lot no.0f7) was returned from a distributor to nakanishi.There was a note with the tip describing the occurrence of tip breakage.Details are as follows.The event occurred on (b)(6) 2016.A dentist was cutting a bone for extraction of a tooth of the patient's lower left jaw using the h-sg1.During the bone cutting, the tip suddenly broke.The breakage occurred on the third use of the tip.Nakanishi is still investigating whether or not the event posed a health hazard to the patient.

Manufacturer Narrative

On september 5, 2016, nakanishi received the information from the distributor that the patient had not been injured by the event and that the patient weight had not been provided from the dentist.Upon receiving the device involved in the mdr event from a distributor, nakanishi conducted a failure analysis of the returned device [c160819-04-1].These activities are described in more detail below.Methodology used: nakanishi examined the device history record and the repair history for the subject h-sg1 device [lot number 0f7].There were no problems observed regarding manufacturing or testing that were noted in the dhr.There were also no repair history records since the device was shipped.Nakanishi conducted a visual inspection of the returned device.Nakanishi observed that the tip was broken into two at the curved part.Nakanishi then performed a visual inspection of the tip using an electronic microscope.Nakanishi observed: - fatigue/ductile fracture on the broken surface of the tip.- deformation/abrasion on the blade of the tip.Nakanishi took photographs of all the damage on the tip and kept them in a file.Conclusions reached based on the investigation and analysis results : nakanishi identified from the above observation that the cause of tip breakage was cutting under high load with a metallically-fatigued tip.Metal fatigue/deformation of the tip led to decreased cutting efficiency, which led to breakage when cutting under high load.Failure to follow the instructions in the operation manual about when to replace the tip led to the above phenomenon, which contributed to the reported breakage of the tip.In order to prevent a recurrence of the tip breakage, 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 distributor and directed the distributor to remind the user of the importance of replacing the bur in a timely manner, as instructed in the operation manual.

• Brand Name: NSK
• Type of Device: SCALER, ULTRASONIC
• 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: 5938803
• MDR Text Key: 54767845
• Report Number: 9611253-2016-00053
• Device Sequence Number: 1
• Product Code: ELC
• Combination Product (y/n): N
• Reporter Country Code: JA
• 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: 01/24/2017

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: H-SG1
• Device Catalogue Number: Z305151
• Device Lot Number: 0F7
• Was Device Available for Evaluation?: Device Returned to Manufacturer
• Date Returned to Manufacturer: 08/19/2016
• Is the Reporter a Health Professional?: No
• Initial Date Manufacturer Received: 08/19/2016
• Initial Date FDA Received: 09/09/2016
• Supplement Dates Manufacturer Received: Not provided
• Supplement Dates FDA Received: 01/24/2017
• Was Device Evaluated by Manufacturer?: Yes
• Date Device Manufactured: 07/14/2016
• 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