Particle generation and dispersion from high-speed dental drilling

M Shyam Kumar; Ruichen He; Lei Feng; Paul Olin; Hooi Pin Chew; Paul Jardine; Gary C Anderson; Jiarong Hong

doi:10.1007/s00784-023-05163-3

Particle generation and dispersion from high-speed dental drilling

Clin Oral Investig. 2023 Sep;27(9):5439-5448. doi: 10.1007/s00784-023-05163-3. Epub 2023 Jul 21.

Authors

M Shyam Kumar¹, Ruichen He^{1

2}, Lei Feng^{1

2}, Paul Olin³, Hooi Pin Chew³, Paul Jardine³, Gary C Anderson³, Jiarong Hong^{4

5}

Affiliations

¹ Department of Mechanical Engineering, University of Minnesota, Minneapolis, MN, USA.
² Saint Anthony Falls Laboratory, University of Minnesota, Minneapolis, MN, USA.
³ University of Minnesota School of Dentistry, Minneapolis, MN, USA.
⁴ Department of Mechanical Engineering, University of Minnesota, Minneapolis, MN, USA. jhong@umn.edu.
⁵ Saint Anthony Falls Laboratory, University of Minnesota, Minneapolis, MN, USA. jhong@umn.edu.

PMID: 37479870
DOI: 10.1007/s00784-023-05163-3

Abstract

Objective: To investigate the characteristics of particle generation and dispersion during dental procedure using digital inline holography (DIH) METHODS: Particles at two locations, near-field and far-field, which represent the field closer to the procedure location and within 0.5 m from the procedure location respectively, are studied using two different DIH systems. The effect of three parameters namely rotational speed, coolant flow rate, and bur angle on particle generation and dispersion are evaluated by using 10 different operating conditions. The particle characteristics at different operating conditions are estimated from the holograms using machine learning-based analysis.

Results: The particle concentration decreased by at least two orders of magnitude between the near-field and far-field locations across the 10 different operating conditions, indicating significant dispersion of the particles. High rotational speed is found to produce a larger number of smaller particles, while lower rotational speeds generate larger particles. Coolant flow rate is found to have a greater impact on particle transport to the far-field location. Irregular shape dental particles account for 29% of total particles at far-field location, with the majority of these irregular shape particles having diameters ranging from 12 to 18 μm.

Conclusions: All three parameters have significant effects on particle generation and dispersion, with rotational speed having a more significant influence on particle generation at near-field and coolant flow rate playing a more important role on particle transport to the far-field.

Clinical relevance: This study provides valuable insights on particle characteristics during high-speed drilling. It can help dental professionals minimize exposure risks for themselves and patients by optimizing clinical operating conditions.

Keywords: Dental public health; Digital inline holography; High speed dental drilling; Imaging; Machine learning; Particle/aerosol generation.