Sterilization effect of atmospheric pressure non-thermal air plasma on dental instruments

Abstract

PURPOSEAutoclaves and UV sterilizers have been commonly used to prevent cross-infections between dental patients and dental instruments or materials contaminated by saliva and blood. To develop a dental sterilizer which can sterilize most materials, such as metals, rubbers, and plastics, the sterilization effect of an atmospheric pressure non-thermal air plasma device was evaluated.MATERIALS AND METHODSAfter inoculating E. coli and B. subtilis the diamond burs and polyvinyl siloxane materials were sterilized by exposing them to the plasma for different lengths of time (30, 60, 90, 120, 180 and, 240 seconds). The diamond burs and polyvinyl siloxane materials were immersed in PBS solutions, cultured on agar plates and quantified by counting the colony forming units. The data were analyzed using one-way ANOVA and significance was assessed by the LSD post hoc test (α=0.05).RESULTSThe device was effective in killing E. coli contained in the plasma device compared with the UV sterilizer. The atmospheric pressure non-thermal air plasma device contributed greatly to the sterilization of diamond burs and polyvinyl siloxane materials inoculated with E. coli and B. subtilis. Diamond burs and polyvinyl siloxane materials inoculated with E. coli was effective after 60 and 90 seconds. The diamond burs and polyvinyl siloxane materials inoculated with B. subtilis was effective after 120 and 180 seconds.CONCLUSIONThe atmospheric pressure non-thermal air plasma device was effective in killing both E. coli and B. subtilis, and was more effective in killing E. coli than the UV sterilizer.

Plasma in dentistry

“…Contaminated endodontic files exposed for a short period to low-pressure oxygen–argon plasma showed a reduction in the absolute amount of proteinaceous materials in a preliminary study, but the exact duration was not described unfortunately [83]. In one experiment using diamond burs and silicone impression materials, the colony-forming unit was significantly reduced for both Escherichia coli and Bacillus subtilis after treatment with atmospheric pressure non-thermal air plasma [84]. The role of low temperature atmospheric pressure plasma and future prospects was well discussed in McCombs’ review [85].…”

Differential Influence of Components Resulting from Atmospheric-Pressure Plasma on Integrin Expression of Human HaCaT Keratinocytes

“…The development of different plasma sources and devices led to an explosion of research in plasma medicine. First, main focus of plasma application was the improvement of chronic infected wounds [1–3] and disinfection of surgical instruments or catheters [4] since plasma is effective in the inactivation of different microorganisms [5–10] and removal of biofilms [11–13]. Meanwhile, nonthermal plasma was also investigated for application in several other fields, for example, in dental applications, in changing surfaces of medical implants, in treating cancer or dermatological diseases, and in plastic surgery [14–16].…”

Plasma applications in medicine and dentistry

“…(2012) koristili su prijenosni generator APPJ kojim su uspjeli inaktivirati 25,5 μm E. faecalis biofilma, što je ukazalo na to da reaktivne vrste ne djeluju inaktivirajuće samo na površinski sloj, već prodiru do dna biofilmova 68 . Sterilizacija Ti diskova, odnosno odstranjivanje S. mutans i biofilmova te sterilizacija stomatoloških instrumenata odstranjivanjem Bacillus subtilis i E. coli, pokazala se uspješnijom od klasične UV sterilizacije 64,69 . Iako nije u potpunosti eliminirao biofilmove s Ti pločica, CAP se ipak pokazao kao metoda superiorna tretiranju laserom i klorheksidinom te zračnom abrazijom 70 .…”