MAUDE Adverse Event Report: NAKANISHI INC. TI-MAX Z; DENTAL HANDPIECE

Model Number	Z99L
Medical Device Problem Code	Overheating of Device (1437)
Health Effect - Clinical Code	Partial thickness (Second Degree) Burn (2694)
Date of Event	04/08/2026
Type of Reportable Event	Serious Injury
Event or Problem Description
During a crown preparation procedure, the handpiece back-cap overheated abnormally, and the patient received a thermal burn injury to the inside of their cheek.The doctor reported the following "i was finalizing my preparation of both #29 and #30, so at that time we took out the cheek retractor i had been using throughout the procedure so the patient could bite, and i could verify my occlusal reduction was adequate.After realizing i needed a minor amount of extra reduction, i tilted my handpiece to be parallel to the occlusal table to do the final adjustment, leading to the back of the handpiece (where i'd push to eject a bur) resting on the patient's cheek.During this last step, the patient abruptly rose her hand and indicated it was hot.I touched the back of the handpiece, and it was extremely hot and charred looking (blackened).At this point i saw a significant burn on the patient's cheek.I re-anesthetized for comfort so we could scan the teeth and fabricated temps.I informed the patient of what happened." the patient was prescribed pain medication and an oral rinse at the time of the incident.The patient reported to the doctor that they were in so much pain after the local anesthesia wore off that they went to an urgent care facility and received a shot for the pain just so they could eat.The pain medication prescribed by the doctor successfully reduced the pain for a few days but was reported to have caused other issues that led to them discontinuing to take it.The patient is reported to have visited an urgent care facility again for pain management and evaluation of a "marble-like" hard mass in their cheek.The result of this evaluation is unknown at the time of this report.A follow-up report will be made as further information becomes available.

• Brand Name: TI-MAX Z
• Common Device Name: DENTAL HANDPIECE
• Manufacturer (Section D): NAKANISHI INC.; 700 shimohinata; kanuma-shi, tochigi-ken 322-8 666; JA 322-8666
• MDR Report Key: 25117505
• Report Number: 1422375-2026-00018
• Device Sequence Number: 10339022
• Product Code: EGS
• UDI-Device Identifier: 04589551391585
• UDI-Public: 04589551391585
• Combination Product (Y/N): N
• Initial Reporter State: CO
• Initial Reporter Country: US
• Number of Events Summarized: 1
• Summary Report (Y/N): N
• Serviced by Third Party (Y/N): N
• Reporter Type: Importer
• Initial Reporter Occupation: Dentist
• Type of Report: Initial
• Report Date (Section B): 05/07/2026
• Report Date (Section F): 04/24/2026

1 Device was Involved in the Event

1 Patient was Involved in the Event

• Is this an Adverse Event Report?: Yes
• Is this a Product Problem Report?: Yes
• Operator of Device: Health Professional
• Device Model Number: Z99L
• Device Catalogue Number: CA13140001
• Was Device Available for Evaluation?: Device Returned to Manufacturer
• Date Returned to Manufacturer: 05/04/2026
• Is the Reporter a Health Professional?: Yes
• Was the Report Sent to FDA?: No
• Distributor Facility Aware Date: 04/21/2026
• Device Age: 5 MO
• Event Location: Outpatient Treatment Facility
• Date Report to Manufacturer: 04/24/2026
• Initial Date Received by Manufacturer: Not provided
• Initial Report FDA Received Date: 05/07/2026
• Is This a Single-Use Device that was Reprocessed and Reused on a Patient? (Y/N): No
• Patient Sequence Number: 1
• Outcome Attributed to Adverse Event: Other
• Patient Age: 47 YR
• Patient Sex: Female
• Patient Ethnicity: Non Hispanic
• Patient Race: White