(G-252) UV-Sensitive Depth Markers for Enhanced Drill Depth Visualization in Dental Practice

Clinicians in dentistry often use various drills for many different procedures, such as removing tooth decay, tooth extraction, or dental implant. In these procedures, precisely controlling the drill depth is critical. The dental clinic uses a special drill bit that has depth markers on the body. However, visualizing these markers is still difficult due to biofluid (e.g., blood, saliva, etc.). In this regard, a UV-sensitive marker was proposed, which irradiates fluorescence under UV light, allowing a highly visible depth indicator [1]. In this abstract, we report a biomedical instrument incorporating UV-sensitive markers on a drill bit with modular electronics that can be attached directly to a dental drill. The attachment will also be portable and rechargeable.

The drill bit was modified such that leaving small dents in the body. UV-sensitive dye that was mixed with the acrylic medium was then applied to those dents (Fig. 1). Four different colors, red, purple, blue, and yellow dyes were used to indicate different depths. The dental drill attachments, a UV LED module, and electronics modules were then developed. The UV LED was incorporated as a neck attachment (l = 395 nm; 604-ATS2012UV395). The rest of the circuits (a rechargeable battery (Li-ion; 30 mAh; CG-425A/M3, Panasonic), a battery charge management module (bq24078Q-Q1, Texas Instruments), a current limiting resistor), and a switch were packaged and mounted on the drill handle. In addition to depth marker functions, the battery life and UV LED irradiance were measured.

We observed glowing fluorescent depth markers as operating the drill. The dot left the afterimage and appeared as lines (Fig. 2). The power consumption during the operation was minimal with an expected run time of 838 hr. The average current consumption was 30.41 ± 0.56 µA with a single full charge. For irradiance testing, a baseline irradiance for adequate marker fluorescence was established at 2.65 ± 0.09 mW/cm². The 838-hour run-time is sufficient for regular clinical use. The low irradiance on the order of milli-watts warrants safety against detrimental UV radiation effects (UV radiation with wavelengths exceeding 315nm has threshold limit values over 1 J/cm² of exposure over an 8-hour workday [2]). 

This work represents preliminary development on a dental drill attachment to increase depth visualization using UV-sensitive depth markers. Depth markers on the drill bit will be a useful addition to a clinician’s toolbox, especially in procedures where depth awareness is important. The accompanying attachment is small, portable, and rechargeable, allowing for convenience and ease of use. Current and future work for this attachment includes many aspects. One improvement will involve optimizing the attachment housing to reduce the size and increase ease of use and ergonomics. The optimal irradiance required for the UV-sensitive markers is to be determined. Biocompatibility and clinical safety testing of these UV-activated markers must also be explored.