| K-number | K254163 |
| Device name | VarioSurg 4 |
| Applicant | Nakanishi, Inc. |
| Product code | DZI |
| Device class | Class II |
| Decision date | Dec 23, 2025 |
| Decision | Substantially Equivalent |
| Regulation | 872.4120 |
The VarioSurg 4 is an ultrasonic surgical system consisting of a control unit, foot control, and ultrasonic handpiece for use in dental procedures. It is intended for bone cutting in oral surgery, scaling and root planing, and retrograde preparation of root canals.
The VarioSurg 4 operates identically to its predicate device, converting an ultrasonic frequency electrical signal into mechanical vibrations via a piezoelectric transducer at 28–32 kHz. Key differences are minor: it features a touch panel display instead of buttons, wireless Bluetooth foot control connectivity (compared to wired), and slightly different control unit dimensions and weight (245×235×90 mm, 2.2 kg), reflecting user convenience and market strategy without affecting safety or effectiveness.
ISO 18397:2016 (Powered scaler), ISO 17664-1:2021 and ISO 17665-1:2006 (reprocessing and sterilization), IEC 62304:2006 (medical device software), IEC 60601-1:2005 and IEC 60601-1-2:2014 (electrical safety and EMC), IEC 81001-5-1:2021 (health IT security), and ISO 10993-1:2018 (biocompatibility).
The subject device is substantially equivalent because it shares identical operating principles, intended use, and fundamental technology with its predicate device (K073678). Non-clinical bench performance testing confirms equivalent safety and effectiveness. Technical differences are limited to minor design variations in shape, display method, and wireless connectivity, all supported by reference devices and compliance with relevant standards, without raising new safety or effectiveness concerns.
View the full FDA submission: accessdata.fda.gov