Banca de DEFESA: ANA BEATRIZ VILLAR MEDEIROS

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : ANA BEATRIZ VILLAR MEDEIROS
DATE: 10/06/2026
TIME: 19:30
LOCAL: CTEC
TITLE:

CONSTRUCTION AND DEVELOPMENT OF A DENTAL INSTRUMENT STERILIZATION EQUIPMENT USING DBD PLASMA

KEY WORDS:

Keywords: Sterilization; Plasma Technology; Dentistry; Bioengineering; Biomechanics

PAGES: 90
BIG AREA: Engenharias
AREA: Engenharia Biomédica
SUMMARY:

Sterilization of dental instruments remains a critical pillar in biosafety programs, particularly given the emergence of multidrug-resistant microorganisms and the limitations imposed by heat-sensitive materials present in contemporary devices. Non-thermal plasma technologies operating at atmospheric pressure, notably dielectric barrier discharge (DBD), have demonstrated potential for microbial inactivation through the generation of reactive oxygen and nitrogen species (ROS/RNS) without inducing thermal damage to substrates. However, consolidating this technology as a viable alternative requires the development of reproducible, safe, and economically accessible systems for clinical settings. This study aimed to design, construct, and experimentally validate a prototype for dental instrument sterilization using cold plasma generated by DBD at atmospheric pressure, ensuring antimicrobial efficacy within timeframes compatible with clinical routines, preservation of material physicochemical integrity, and technical-economic feasibility for acquisition. The development comprised four phases: (i) systematic literature review (2021–2026) in indexed databases (PubMed, Scopus, Web of Science); (ii) detailed engineering design, including treatment chamber geometry, electrode and dielectric barrier configuration, exhaust system, and mitigation of gaseous by-products (notably ozone); (iii) instrumentation for real-time monitoring and control of process variables: voltage, frequency, relative humidity, temperature, gas flow, and exposure time; (iv) in vitro microbiological validation using standardized strains of Escherichia coli (ATCC 25922) and Staphylococcus aureus (ATCC 25923). Bacterial suspensions were exposed to plasma at a fixed distance of 1 cm for 2, 10, and 15 minutes, with viability assessed by colony-forming unit (CFU/mL) counting after incubation. The developed prototype exhibited a stable and reproducible operational window, with electrical and environmental parameters controlled within specified ranges. Microbiological assays revealed time-dependent inactivation efficacy, with log reductions greater than 5 CFU/mL for both microorganisms at 10 and 15 minutes, demonstrating treatment uniformity even on substrates with complex geometries. Preliminary analyses indicated process compatibility with different materials composing the instruments, with no apparent macroscopic or functional alterations. The integration of precise process parameter control with robust microbiological validation enabled the development of a DBD system with high potential for dental sterilization/decontamination applications. The prototype demonstrates technical viability for effective microbial inactivation within clinically relevant timeframes, positioning itself as a promising alternative to conventional methods, particularly for heat-sensitive instruments. Complementary studies involving biofilms and different material classes are necessary for definitive pre-clinical validation.

COMMITTEE MEMBERS:
Presidente - 1752038 - CUSTODIO LEOPOLDINO DE BRITO GUERRA NETO
Interno - 350690 - ANGELO RONCALLI OLIVEIRA GUERRA
Externa à Instituição - TATIANA OLIVEIRA SOUZA - FACENE