H.Guan¹,M.Nuth¹, S.R. Weiss², A. Fausto², Y. Liu³, H. Koo³, M.S. Wolff⁴ , and R.P. Ricciardi^1,5

Abstract

The COVID-19 pandemic has escalated the risk of SARS-CoV-2 transmission in the dental practice, especially as droplet-aerosol particles are generated by high-speed instruments. This has heightened awareness of other orally transmitted viruses, including influenza and herpes simplex virus 1 (HSV1), which are capable of threatening life and impairing health. While current disinfection procedures commonly use surface wipe-downs to reduce viral transmission, they are not fully effective. Consequently, this provides the opportunity for a spectrum of emitted viruses to reside airborne for hours and upon surfaces for days. The objective of this study was to develop an experimental platform to identify a safe and effective virucide with the ability to rapidly destroy oral viruses transported within droplets and aerosols. Our test method employed mixing viruses and virucides in a fine-mist bottle atomizer to mimic the generation of oral droplet-aerosols. The results revealed that human betacoronavirus OC43 (related to SARS-CoV-2), human influenza virus (H1N1), and HSV1 from atomizer-produced droplet-aerosols were each fully destroyed by only 100 ppm of hypochlorous acid (HOCl) within 30 s, which was the shortest time point of exposure to the virucide. Importantly, 100 ppm HOCl introduced into the oral cavity is known to be safe for humans. In conclusion, this frontline approach establishes the potential of using 100 ppm HOCl in waterlines to continuously irrigate the oral cavity during dental procedures to expeditiously destroy harmful viruses transmitted within aerosols and droplets to protect practitioners, staff, and other patients.

Keywords: virucide, saliva, infection, high-speed instruments, waterlines, prevention

Tingting Yin¹ , Qiaowen Li² , Huan Sun³ , Jin Zheng⁴ , Yuanyuan Wang⁵ , Yi Luo6 and Li Wang^7*

Abstract

Background This work intended to assess the disinfection efficacy of hypochlorous acid (HA) and silver nanoparticles (AgNP) disinfectants in disinfecting the dental unit waterlines (DUWL) during comprehensive oral treatment and explore their potential applications in the oral medical environment. Methods: Firstly, AgNP solution was prepared and evaluated through X-ray diffraction (XRD), field emission transmission electron microscope (FE-TEM), and stability tests. Subsequently, 15 dental units were selected and randomly assigned to three groups, each receiving a different disinfection method. Specifically, one group (5 units) received HA disinfectant (HA group), one group (5 units) received AgNP disinfectant (AgNP group), and another group (5 units) received a combination of HA and AgNP disinfectant (HA+AgNP group). Bacterial counts before and after disinfection were compared and analyzed at four sites on the dental units: high-speed handpiece tubing, mouthwash, ultrasonic scaler, and three-way syringe.

Results The growth of biofilm on the waterlines was observed using scanning electron microscopy (SEM) and laser confocal microscopy (LCM). The results indicated that AgNP solution was successfully prepared and demonstrated excellent stability. There was no significant difference in the average weekly number of patients treated across the three groups (P>0.05). After disinfection, bacterial counts were significantly reduced in all groups. Compared to the HA and AgNP groups, the HA+AgNP group exhibited a markedly lower bacterial count, with statistical significance (P<0.05). The compliance rates observed during the first disinfection and two weeks post-disinfection were slightly lower in the HA and AgNP groups compared to the HA+AgNP group, although no significant statistical difference was found (P>0.05). SEM images revealed uneven biofilm plaques on the inner surface of the pipes prior to disinfection, embedded within a dense matrix, while the biofilm was visibly disrupted post-disinfection. LCM software analysis showed that, compared to the HA and AgNP groups, the HA+AgNP group had a significantly lower percentage of live bacteria on the biofilm post-disinfection (P<0.05).

Conclusion Compared to any single disinfectant regimen, the combined use of HA and AgNPs effectively inhibited bacterial growth and exerted a significant destructive effect on biofilms. Therefore, this combination is expected to be a viable option for disinfection of DUWL in the oral healthcare setting.

Clinical trial number Not applicable.

Keywords Dentistry, Therapeutics, Waterline disinfectant, Hypochlorous acid, Silver nanoparticles

Chun-Ju Chen ¹ , Chun-Cheng Chen ^2,3,* and Shinn-Jyh Ding ^1,2,3,*

¹Institute of Oral Science, Chung Shan Medical University, Taichung City 402, Taiwan; 该Email地址已收到反垃圾邮件插件保护。要显示它您需要在浏览器中启用JavaScript。

²School of Dentistry, Chung Shan Medical University, Taichung City 402, Taiwan

³Department of Dentistry, Chung Shan Medical University Hospital, Taichung City 402, Taiwan

^*Correspondence: 该Email地址已收到反垃圾邮件插件保护。要显示它您需要在浏览器中启用JavaScript。 (C.-C.C.); 该Email地址已收到反垃圾邮件插件保护。要显示它您需要在浏览器中启用JavaScript。 (S.-J.D.); Tel.: +886-6-2471-8668 (ext. 55255) (C.-C.C.); +886-6-2471-8668 (ext. 55529) (S.-J.D.)

Academic Editor: Ihtesham ur Rehman

Received: 13 April 2016; Accepted: 15 July 2016; Published: 19 July 2016

Abstract: Chemotherapeutic agents have been used as an adjunct to mechanical debridement for peri-implantitis treatment. The present in vitro study evaluated and compared the effectiveness of hypochlorous acid (HOCl), sodium hypochlorite (NaOCl), and chlorhexidine (CHX) at eliminating Gram-negative (E. coli and P. gingivalis) and Gram-positive (E. faecalis and S. sanguinis) bacteria. The effect of irrigating volume and exposure time on the antimicrobial efficacy of HOCl was evaluated, and a durability analysis was completed. Live/dead staining, morphology observation, alamarBlue assay, and lipopolysaccharide (LPS) detection were examined on grit-blasted and biofilm-contaminated titanium alloy discs after treatment with the three chemotherapeutic agents. The results indicated that HOCl exhibited better antibacterial efficacy with increasing irrigating volumes. HOCl achieved greater antibacterial efficacy as treatment time was increased. A decrease in antimicrobial effectiveness was observed when HOCl was unsealed and left in contact with the air. All the irrigants showed antibacterial activity and killed the majority of bacteria on the titanium alloy surfaces of biofilm-contaminated implants. Moreover, HOCl significantly lowered the LPS concentration of P. gingivalis when compared with NaOCl and CHX. Thus, a HOCl antiseptic may be effective for cleaning biofilm-contaminated implant surfaces.

Keywords: dental implant; hypochlorite acid; antiseptics; antimicrobial activity

Dita Mutiara Irawan ¹ , Ronny Lesmana^2–4 , Edhyana Sahiratmadja 4

¹Graduate School of Master Program in Anti Aging and Aesthetic Medicine, Faculty of Medicine, Universitas Padjadjaran,Jatinangor, 45363, Indonesia;²Center of Excellence in Higher Education for Pharmaceutical Care Innovation, Universitas Padjadjaran, Jatinangor, 45363, Indonesia; ³Division of Biological Activity, Central Laboratory, Universitas Padjadjaran, Sumedang, 45363, Indonesia; ⁴Department of Biomedical Science, Faculty of Medicine, Universitas Padjadjaran, Sumedang, 45363, Indonesia

Correspondence: Dita Mutiara Irawan, Email 该Email地址已收到反垃圾邮件插件保护。要显示它您需要在浏览器中启用JavaScript。

Background: People who suffered type 2 diabetes have impaired healing of wounds due to the large number of circulating inflammatory cells resulting from high blood sugar levels. The wound healing process involves various complex processes including

the degradation of extracellular matrix, a process characterized by an increase in matrix metalloproteinase-9 (MMP-9). Conventional management of diabetic wounds usually involves systemic blood sugar control and topical antimicrobial treatment, including hydrogen peroxide and povidone-iodine, which are known to be cytotoxic to the cells involved in the wound healing cascade. Finding a safe, non-toxic, and effecting wound cleansing still poses a challenge, and hypochlorous acid (HOCl) could act as a potential candidate.

Purpose: Unveiling an HOCl ion as an agent for diabetic wound management and MMP-9 as a marker for delayed diabetic wound

Methods: The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) Flow Diagram is used to find and select related, eligible literatures for the review. The authors used several databases such as Pro Quest, Scopus, Springer link and

Science Direct. In addition, and to expand the data, the database on Google Scholar was also opened. Then, the compiled data are analyzed to form results and discussions to the research question.

Results: Five eligible articles passed the inclusion criteria and reviewed for data synthesis. From 5 pieces of literature, it was found that the use of HOCl ions can be a good choice of topical agent in the management of diabetic wounds and decrease the activity of

MMP-9, which act as a marker for delayed healing of diabetic wounds.

Conclusion: Topical agent, in this case HOCl ion, shows good results and can be used as an option in the management of diabetic wounds and MMP-9 can be used as a predictive marker in the management of diabetic wounds.

Keywords: diabetic wound, HOCl ion, hypochlorite acid, MMP-9, wound healing