NSK SGS-E2S H185

MAUDE Adverse Event Report

MAUDE data represents reports of adverse events involving medical devices. This maude entry was filed with the FDA on 2016-11-01 for NSK SGS-E2S H185 manufactured by Nakanishi Inc..

Event Text Entries

[58934309] (b)(4). (b)(4) took the following actions for more information about the event, however, the detailed information was not provided. - on (b)(6) 2016, right after becoming aware of the event, (b)(4) contacted the dental office, but the office manager was not available at the time to take the call. (b)(4) left a voice mail message with a request for a return call. The office manager returned the call to (b)(4) and refused to provide the details from a place of the office manager. The assistant and the dentist was not in the office to provide the information. The manager requested (b)(4) to email the information request form (qa-011) to the office and promised to complete and send back the form immediately. (b)(4) sent the information form as requested. No response was returned from the dental office. - on october 3, 2016, (b)(4) sent a follow-up email to the office manager to ask if the email and the request form were received and if any assistance was needed. (b)(4) received no response. - on october 5, 2016, (b)(4) made a phone call and spoke with the office manager. The manager promised again that the dental office would forward the information as soon as possible. (b)(4) received no response. - on october 11, 2016, (b)(4) left a voice mail message inquiring about the requested paperwork, but (b)(4) did not receive any response. - october 11, 2016, (b)(4) called and left a voice mail message. In addition, (b)(4) sent an email to follow up to the message. No response was returned. Despite all the above efforts, (b)(4) could not obtain the further information including the patient information.
Patient Sequence No: 1, Text Type: N, H10


[58934310] On october 13, 2016, nakanishi received an e-mail from a distributor ((b)(4)) about handpiece overheating. Details are as follows. - on september 30, 2016, (b)(4) was made aware of the event by incoming service repair paperwork. - the event occurred on (b)(6) 2016. - an nsk handpiece, sgs-e2s (serial no. : (b)(4)) overheated and burned a patient's lip.
Patient Sequence No: 1, Text Type: D, B5


[68247501] Upon receiving the device involved in the mdr event from a distributor, nakanishi conducted a failure analysis of the returned device that included measuring the temperature of the operating device [c161014-11-1]. These activities are described in more detail below. Methodology used: a) nakanishi examined the device history record and the repair history for the subject sgs-e2s 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. B) nakanishi conducted a visual inspection of the returned device and performed a simple movement test. There were no visible abnormalities, such as cracks or dents, on the outside of the handpiece. Nakanishi then set a test bur in the handpiece and rotated it by hand. Nakanishi observed that the bur did not rotate smoothly. C) nakanishi conducted temperature testing of the returned device in the following manner: c. 1) temperature sensors were attached to the exterior of the device at various test points. This included the point most proximal to the patient (testing point (1)) and points further toward the distal end of the device (testing points (2) through (4)). The test setup was prepared to take temperature measurements at all points simultaneously, including a reference measurement at ambient room temperature. C. 2) nakanishi attached a thermocouple (sensor to measure a temperature) to each of the testing points. Nakanishi rotated the device's motor at 40,000 min-1, which is the maximum rpm for the motor that drives the handpiece (80,000 min-1 for the handpiece), and measured the exothermic situation. C. 3) nakanishi measured the temperature rise of the returned handpiece set at 80,000 min-1 (motor revolution 40,000 min-1). Nakanishi observed an abnormal temperature rise at test point (2) 30 seconds after the start. Temperature measurements 30 seconds after the start are as follows: - test point (1): 48. 7 degrees c - test point (2): 73. 6 degrees c - test point (3): 30. 7 degrees c - test point (4): 40. 4 degrees c the rise in temperature was so sudden that the test was ended only 30 seconds into the planned 5 minute evaluation period. D) nakanishi washed the inside of the handpiece using nakanishi pana spray plus. Nakanishi observed dirt being expelled from the head of the handpiece by using a white filter to catch anything that was expelled. E) after cleaning and lubricating the handpiece as defined in the operation manual, nakanishi measured the temperature of the handpiece. Even after cleaning, nakanishi still observed a quick rise in temperature, as follows. - test point (1): 43. 0 degrees c - test point (2): 66. 1 degrees c - test point (3): 23. 2 degrees c - test point (4): 33. 6 degrees c identification of the specific failure mode(s) and/or mechanism(s) and the associated device components involved: a) nakanishi disassembled the handpiece and performed a visual inspection of the inside parts. Nakanishi observed the following phenomena: - dirt on the bearing incorporated in test point (1). - the bearing incorporated in test point (2) was completely broken and the inner race was only seen in the bearing. - dirt and abrasions in the inside parts. B) nakanishi took photographs of all of the disassembled parts and kept them in a file. C) nakanishi then replaced the broken bearings and measured the exothermic situation yet again. There was no abnormal rise in temperature during the test period (see below). Nakanishi confirmed that the returned handpiece was operating as expected and within temperature specifications once the damaged bearings had been replaced. - test point (1): 43. 7 degrees c - test point (2): 40. 0 degrees c - test point (3): 37. 1 degrees c - test point (4): 39. 8 degrees c conclusions reached based on the investigation and analysis results: 1) nakanishi identified that the cause of the overheating of the returned device was abnormal resistance during rotation caused by the broken/worn bearings due to the ingress of dirt into the bearings. 2) 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/worn bearings. This contributes to the handpiece overheating. 3) in order to prevent a recurrence of the handpiece overheating, nakanishi took the following actions: 3. 1) nakanishi reviewed the operation manual and reconfirmed clarity and understandability of the instructions. 3. 2) nakanishi reported the above evaluation results to nsk america and directed nsk america to remind the user of the importance of maintenance, as instructed in the operation manual.
Patient Sequence No: 1, Text Type: N, H10


MAUDE Entry Details

Report Number9611253-2016-00063
MDR Report Key6069928
Date Received2016-11-01
Date of Report2018-07-10
Date of Event2016-09-20
Date Facility Aware2016-09-30
Date Mfgr Received2018-06-09
Device Manufacturer Date2014-01-29
Date Added to Maude2016-11-01
Event Key0
Report Source CodeManufacturer report
Manufacturer LinkY
Number of Patients in Event0
Adverse Event Flag3
Product Problem Flag3
Reprocessed and Reused Flag3
Reporter OccupationDENTIST
Health Professional3
Initial Report to FDA3
Report to FDA3
Event Location3
Manufacturer ContactMR KENNETH BLOCK
Manufacturer Street800 E CAMPBELL RD. SUITE 202
Manufacturer CityRICHARDSON TX 75081
Manufacturer CountryUS
Manufacturer Postal75081
Manufacturer Phone9724809554
Manufacturer G1NAKANISHI INC. REGISTRATION NUMBER : 9611253
Manufacturer StreetMFR RPT# : 9611253-2016-00063 700 SHIMOHINATA
Manufacturer CityKANUMA-SHI, TOCHIGI-KEN 322-8666
Manufacturer CountryJA
Manufacturer Postal Code322-8666
Single Use3
Previous Use Code3
Removal Correction Number9611253-060818-001-R
Event Type3
Type of Report3

Device Details

Brand NameNSK
Generic NameHANDPIECE, ROTARY BONE CUTTING
Product CodeKMW
Date Received2016-11-01
Returned To Mfg2016-10-19
Model NumberSGS-E2S
Catalog NumberH185
OperatorDENTIST
Device AvailabilityR
Device Age2 YR
Device Eval'ed by MfgrY
Device Sequence No1
Device Event Key0
ManufacturerNAKANISHI INC.
Manufacturer Address700 SHIMOHINATA KANUMA-SHI, TOCHIGI-KEN 322-8666 JA 322-8666


Patients

Patient NumberTreatmentOutcomeDate
101. Other 2016-11-01

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