MAUDE data represents reports of adverse events involving medical devices. This maude entry was filed from a company representative report with the FDA on 2018-08-30 for NSK SGS-E2S H266 manufactured by Nakanishi Inc..
[118765136]
(b)(4).
Patient Sequence No: 1, Text Type: N, H10
[118765137]
On august 8, 2018, nakanishi received an e-mail from a distributor ((b)(4)) about a handpiece overheating. Details are as follows. The event occurred on (b)(6) 2018. A dentist was performing a third molar extraction on a patient using the sgs-e2s handpiece (serial no. : (b)(4)). The patient was under anesthesia (moderate sedation). According to the dentist, the handpiece was warm to touch prior to observing the injury. After the procedure was completed, the patient returned home and reported a burn on the lower left lip, approximately 6mm wide and 1cm long, extending distally. The dentist sent the patient an ointment cream with care instructions. The dentist discovered from the communication with the patient over the phone and through email that the patient's injury had healed normally but the lower lip was scarred.
Patient Sequence No: 1, Text Type: D, B5
[123738422]
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 operating temperature of the device [(b)(4)]. These activities are described in more detail below. Methodology used: nakanishi examined the device history record and the repair history for the subject sgs-e2g 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 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. Nakanishi conducted temperature testing of the returned device in the following manner: 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. 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), with water spray, and measured the exothermic response. 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 (1) and (2) a few seconds after the start. Temperature measurements 39 seconds after the start are as follows: test point (1): 69. 1 degrees c; test point (2): 71. 2 degrees c; test point (3): 33. 8 degrees c; test point (4): 35. 7 degrees c; the rise in temperature was so sudden that the test was concluded 39 seconds into the planned 5 minute evaluation period. Nakanishi cleaned the inside of the handpiece using nakanishi pana spray plus. Nakanishi observed debris being expelled from the head of the handpiece by using a white filter to catch anything that was expelled. After cleaning and lubricating the handpiece as defined in the operation manual, nakanishi measured the temperature of the handpiece for the entire 5-minute evaluation period. Even after cleaning, nakanishi observed a quick rise in temperature, as follows. Test point (1): 69. 0 degrees c; test point (2): 70. 9 degrees c; test point (3): 30. 9 degrees c; test point (4): 39. 5 degrees c. 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 the following phenomena: there was massive debris on the bearing incorporated in the test point (1). The bearing incorporated in the test point (2) was broken. There was debris and corrosion on the other parts. Nakanishi took photographs of all of the disassembled parts and kept them in the investigation report # (b)(4). Nakanishi then replaced the broken bearings with new bearings and measured the exothermic situation yet again. There was no abnormal rise in temperature during the 300-second-test period (see below). Nakanishi confirmed that the returned handpiece was operating as expected and within temperature specifications once the broken bearings had been replaced. Test point (1): 48. 4 degrees c; test point (2): 46. 1 degrees c; test point (3): 44. 4 degrees c; test point (4): 43. 8 degrees c. Conclusions reached based on the investigation and analysis results: nakanishi identified that the cause of the overheating of the returned device was abnormal resistance during rotation caused by the corroded/broken bearings due to the ingress of undesirable materials into the bearings. A lack of maintenance causes the accumulation of debris on the inside parts, which causes debris ingress into the bearing during rotation. This contributes to the handpiece overheating. Nakanishi shipped the updated operation manuals that contain detailed reprocessing methods to nsk america. Nsk america will distribute the updated manuals to the sub-distributors and users including the complainant to convey the detailed reprocessing methods to prevent a recurrence of the handpiece overheating.
Patient Sequence No: 1, Text Type: N, H10
| Report Number | 9611253-2018-00039 |
| MDR Report Key | 7832640 |
| Report Source | COMPANY REPRESENTATIVE |
| Date Received | 2018-08-30 |
| Date of Report | 2018-10-15 |
| Date of Event | 2018-06-01 |
| Date Facility Aware | 2018-06-25 |
| Report Date | 2018-08-08 |
| Date Reported to Mfgr | 2018-08-08 |
| Date Mfgr Received | 2018-09-19 |
| Device Manufacturer Date | 2014-09-29 |
| Date Added to Maude | 2018-08-30 |
| Event Key | 0 |
| Report Source Code | Manufacturer report |
| Manufacturer Link | Y |
| Number of Patients in Event | 0 |
| Adverse Event Flag | 3 |
| Product Problem Flag | 3 |
| Reprocessed and Reused Flag | 3 |
| Reporter Occupation | PHYSICIAN ASSISTANT |
| Health Professional | 3 |
| Initial Report to FDA | 3 |
| Report to FDA | 3 |
| Event Location | 3 |
| Manufacturer Contact | MR KENNETH BLOCK |
| Manufacturer Street | 800 E CAMPBELL RD. SUITE 202 |
| Manufacturer City | RICHARDSON TX 75081 |
| Manufacturer Country | US |
| Manufacturer Postal | 75081 |
| Manufacturer Phone | 9724809554 |
| Manufacturer G1 | NAKANISHI INC. REGISTRATION NUMBER : 9611253 |
| Manufacturer Street | MFR RPT# : 9611253-2018-00039 700 SHIMOHINATA |
| Manufacturer City | KANUMA-SHI, TOCHIGI-KEN 322-8666 |
| Manufacturer Country | JA |
| Manufacturer Postal Code | 322-8666 |
| Single Use | 3 |
| Remedial Action | RC |
| Previous Use Code | 3 |
| Removal Correction Number | 9611253-060818-001-R |
| Event Type | 3 |
| Type of Report | 3 |
| Brand Name | NSK |
| Generic Name | HANDPIECE, ROTARY BONE CUTTING |
| Product Code | KMW |
| Date Received | 2018-08-30 |
| Model Number | SGS-E2S |
| Catalog Number | H266 |
| Operator | HEALTH PROFESSIONAL |
| Device Availability | N |
| Device Age | 4 YR |
| Device Eval'ed by Mfgr | R |
| Device Sequence No | 1 |
| Device Event Key | 0 |
| Manufacturer | NAKANISHI INC. |
| Manufacturer Address | 700 SHIMOHINATA KANUMA-SHI, TOCHIGI-KEN 322-8666 JA 322-8666 |
| Patient Number | Treatment | Outcome | Date |
|---|---|---|---|
| 1 | 0 | 1. Other | 2018-08-30 |