In these last weeks, in several countries of the world, cases are spreading more and more, causing many problems in the population. The person-to-person transmission routes of 2019-nCoV included direct transmission, such as cough, sneeze, droplet inhalation transmission, and contact transmission, such as the contact with oral, nasal, and eye mucous membranes. 2019-nCoV can also be transmitted through the saliva, and the fetal–oral routes may also be a potential person-to-person transmission route.
For what concern dental offices, dentists and patients are exposed to tremendous risk of 2019-nCoV infection due to the face-to-face communication and the exposure to saliva, blood, and other body fluids, and the handling of sharp instruments.
Dentists play great roles in preventing the transmission of 2019-nCoV.In the study published in the International Journal of Oral Science, Xian Peng et al. try to recommend how to behave in dental offices to block the person-to-person transmission routes.
1)Schedule appointments to not have more than one patient in the waiting room.
2)Patient evaluation: dental professionals should be able to identify a suspected case of COVID-19. These patients have fever >37.3 ° C, coughs, breathing difficulties, muscle pains, headaches in the last 14 days.
Call al the patients the day before the appointment and ask them if:
-they have these symptoms,
-they have been in contact with infected people or with these symptoms for the past two weeks
-they attended events in crowded places
-they come from risk areas. If a patient replies “yes” to any of the screening questions, and his/her body temperature is no less than 37.3 °C, the patient should be immediately quarantined, and the dental professionals should report to the infection control department of the hospital or the local health department. If a patient replies “no” to all the screening questions, and his/her body temperature is below 37.3 °C, the dentist can treat the patient with extra- protection measures, and avoids spatter or aerosol-generating procedures to the best. If a patient replies “no” to all the screening questions, but his/her body temperature is no less than 37.3 °C, the patient should be instructed to the fever clinics or special clinics for COVID-19 for further medical care.
3)Hand hygiene: Fecal–oral transmission has been reported for 2019-nCoV, which underlines the importance of hand hygiene for dental practice. Although appropriate hand hygiene is the routine prerequisite for dental practice, hand-washing compliance is relatively low, which imposes a great challenge to the infection control during the epidemic period of 2019-nCoV transmission. It's important to wash hands before and after patients examination and to avoid touching their own eyes, mouth and nose
4)Personal protective: three-level protective measures of the dental professionals are recommended for specific situations.
-Primary protection (standard protection for staff in clinical settings). Wearing disposable working cap, disposable surgical mask, and working clothes (white coat), using protective goggles or face shield, and disposable latex gloves or nitrile gloves if necessary.
-Secondary protection (advanced protection for dental professionals). Wearing disposable doctor cap, disposable surgical mask, protective goggles, face shield, and working clothes (white coat) with disposable isolation clothing or surgical clothes outside, and disposable latex gloves.
-Tertiary protection (strengthened protection when contact patient with suspected or confirmed 2019-nCoV infection).
5)Mouthrinse: chlorhexidine, which is commonly used as mouthrinse in dental practice, may not be effective to kill 2019-nCoV. Since 2019-nCoV is vulnerable to oxidation, preprocedural mouthrinse containing oxidative agents such as 1% hydrogen peroxide or 0.2% povidone is recommended, for the purpose of reducing the salivary load of oral microbes, including potential 2019-nCoV carriage. A preprocedural mouthrinse would be most useful in cases when rubber dam cannot be used.
6)Rubber dam isolation: The use of rubber dams can significantly minimize the production of saliva- and blood-contaminated aerosol or spatter. When rubber dam is applied, extra high-volume suction for aerosol and spatter should be used during the procedures along with regular suction. If rubber dam isolation is not possible in some cases, manual devices, such as Carisolv and hand scaler, are recommended for caries removal and periodontal scaling, in order to minimize the generation of aerosol as much as possible.
7)Anti-retraction handpiece: the anti-retraction high-speed dental handpiece can significantly reduce the backflow of oral bacteria and HBV into the tubes of the handpiece and dental unit as compared with the handpiece without anti-retraction function60. Therefore, the use of dental handpieces without anti-retraction function should be prohibited during the epidemic period of COVID-19.
8)Disinfection of the clinic settings: Medical institutions should take effective and strict disinfection measures in both clinic settings and public area. Public areas and appliances should also be frequently cleaned and disinfected, including door handles, chairs, and desks. The elevator should be disinfected regularly. People taking elevators should wear masks correctly and avoid direct contact with buttons and other objects.
9)Management of medical waste: The medical waste (including disposable protective equipment after use) should be transported to the temporary storage area of the medical institute timely. The reusable instrument and items should be pretreated, cleaned, sterilized, and properly stored. Double-layer yellow color medical waste package bags and “gooseneck” ligation should be used. The surface of the package bags should be marked and disposed according to the requirement for the management of medical waste.
For additional informations: Transmission routes of 2019-nCoV and controls in dental practice
Oral Hygiene & Prevention 26 February 2020
Restorative dentistry 08 April 2020