Dental setup in the covid-ified era – A review

Introduction

“The measure of intelligence is the ability to change”- this famous quote by Albert Einstein is the rule for the present era. With the emergence of the COVID-19, dentists face a herculean task of upgrading their dental office by means of incorporating a wide range of measures to enhance the hygiene of the dental office, thereby creating a better clean and safe environment for dental practice. Coronaviruses belong to the family of Coronaviridae, of the order Nidovirales, comprising large, single, plus-stranded RNA as their genome. Coronaviruses have traditionally been associated with mild upper respiratory tract infections throughout the world. In the fall of 2002, a new coronavirus emerged in in Asia causing severe viral pneumonia, i.e., severe acute respiratory syndrome (SARS).^[1] Middle East respiratory syndrome (MERS) is a new human disease first reported from Saudi Arabia in September, 2012, after identification of a novel coronavirus (CoV) from a male Saudi Arabian patient who died from severe respiratory illness. The virus was designated MERS-CoV.^[2] Last year, in late December a pneumonia outbreak emerged in the city of Wuhan, China which spread very rapidly through the city following which WHO declared a public emergency worldwide on January 30, 2020. The typical clinical symptoms of the patients who suffered from the novel viral pneumonia were fever, cough, and myalgia or fatigue with abnormal chest CT, and the less common symptoms were sputum production, headache, hemoptysis, and diarrhea.^[3] The infectious agent of this viral pneumonia happening in Wuhan was finally identified as a novel coronavirus (2019-nCOV), the 7^th member of the family of coronaviruses that infect humans.^[4] On 11th February 2020, WHO named the novel viral pneumonia as “Corona Virus Disease (COVID19)”, while the international Committee on Taxonomy of Viruses (ICTV) suggested this novel coronavirus name as “SARSCoV- 2” relating to the phylogenetic and taxonomic analysis of this novel coronavirus.^[5]

Mode of Transmission

The common transmission routes of novel coronavirus include direct transmission like cough, sneeze, and droplet inhalation transmission and contact transmission contact with oral, nasal, and eye mucous membranes.^[6] In addition, studies have shown that respiratory viruses can be transmitted from person to person through direct or indirect contact, or through coarse or small droplets, and 2019-nCoV can also be transmitted directly or indirectly through saliva. Notably, a report of one case of 2019-nCoV infection in Germany indicates that transmission of the virus may also occur through contact with asymptomatic patients.^[7]

It has been reported by King et al. that after ultrasonic scaling, bacteria could be recovered 6 inches from the mouth of the patient and that the number of colony forming units was significantly reduced when an aerosol reduction device was used during scaling.^[8] Live viruses (COVID-19) were isolated from the saliva.^[9] Hence, healthcare workers particularly the dental professionals are at more risk. Considering that numerous kinds of dental equipments that are used in the clinical practice in the form of handpieces, air-water syringes and ultrasonic scalers considerable amounts of aerosols are produced. Hence, the potential for the spread of infections from patients to dentists or dental assistants is high.^[10]

Consequently, the air in dental clinics is likely to be contaminated with several microorganisms to which workers are potentially exposed. Because of the high concentration of bacteria in the oral cavity (nearly of 1.0 E+07–1.0 E+08 colony forming units (CFU)/mL of saliva) and due to concerns of cross contamination between dentists and patients, oral bacteria have been identified as components of dental bioaerosols.^[11]

Setup of Dental Office

Patient awareness, education and co-operation play a major role in effective implementation of any control measures in a dental clinic. Hence in the wake of the Covid-19 pandemic, the role of the front office and the reception staff assumes a very significant place and forms the first line of defence. This is also the stage where the patient screening is done.

Front – room setup

Role of reception staff

The front office/reception staff should be well trained by the management and made aware of the Covid-19 precautionary measures.

The front office staff should always wear 3-ply masks, gloves, when they are in the reception area.

Should wear separate foot wear inside the clinic. It is recommended to sprinkle 1% Bleaching solution on the floor mat / carpet or spread a cloth soaked in 1% bleaching solution to disinfect the feet of patients.

Should instruct the patients and bystanders to wash their hands with soap and water for 20secs before being seated in the clinic.

Should check the temperature of patients using a non-contact infrared scanner thermometer. Treatment for a patient with a measured temperature ≥38 C° (100.4° F) should be deferred.

They should open the doors for the patients to enter the operatory to minimise contamination.

Importance of hand hygiene, social distancing, unnecessarily touching MEN (mouth, eyes, nose) or the T-zone on the face, spitting and putting fingers inside the mouth.

Should categorize the patients after having proper communication with the patient. ([Figure 2])

Waiting area setup

A hand wash facility conveniently placed outside the clinic for the patients as soon as they arrive. A poster depicting the WHO recommended hand wash techniques to be displayed in the wash area.

Provide Hand sanitisers in the waiting area.

Remove all articles like newspapers, magazines, print material, flower vases, showcase artefacts, toys, carpets etc from the waiting area to reduce areas that are not amenable for disinfection.

The seating pattern in the waiting area should be arranged in a manner to ensure physical distancing.

The waiting area should be mopped and disinfected, every two hours, using 1% NaOCl solution.

Audio/visual alerts can also be used in addition to educate and motivate the patients.

Personel protective equipment ([Figure 3])

3-ply masks and a pair of gloves should be worn by dental practitioners always inside the clinic.

N95 masks, head cap, goggles or face-shield, have to be worn by practitioners while doing procedures.

A surgical glove worn above the examination gloves is advisable (Double gloves).

A gown with long sleeves, Fluid resistant material (Ideally of 70 gsm or above.

If reusable, the material should be certified by a recognised body like South India Textile Research Association (SITRA), Defence Research and Development Organization (DRDO) as recommended by Government of India to ensure that the barrier properties are retained even after wash/disinfection) is recommended for additional protection.

3 Tests to check the quality of 3 ply-masks before purchasing – this is necessary because of the duplicate products that are released over this period of time.

Visual test ([Figure 4])

Cut open the mask and you should see a very obvious 3-layers.

Translucent piece (top), White piece (middle), and the coloured piece (Green, Blue, or even White).

Waste categories	Description
Infectious waste	Waste suspected to contain pathogens; e.g., laboratory cultures, tissues, swabs, materials or equipment that have been in contact with infected patients, excreta, etc
Pathological waste	Human tissues or fluids; e.g., body parts, blood and other body fluids, fetuses, etc
Sharps	Sharp waste; e.g., needles, scalpels, blades, knives, infusion sets, broken glass
Pharmaceutical waste	Waste containing pharmaceuticals; e.g., pharmaceuticals that are expired or no longer needed, items contaminated by or containing pharmaceutics (bottles, boxes)
Genotoxic waste	Waste containing substances with genotoxic properties; e.g., cytotoxic drugs (cancer drugs), genotoxic chemicals
Chemical Waste	Waste containing chemical substances; e.g., laboratory reagents, film developer, fixer, disinfectants that are expired or no longer needed, solvents
Wastes with high content of heavy metals	Batteries, broken thermometers, blood pressure gauges, etc
Pressurized containers	Gas cylinders, gas cartridges, aerosol Cans
Radioactive Waste	Waste containing radioactive substances; e.g., unused liquids from radiotherapy or laboratory research, contaminated glassware, packages or absorbent paper, urine and excreta from patients treated or tested with unsealed radionuclides, sealed sources

Table 1 WHO Classification ofhealth care waste12

Red bag	Yellow bag	Blue bag	Black carboy
Disposable injection syringes, IV set without needleSaline bottlesPlastic suction tipsToothbrushes, denture brushesDisposable plastic/fiber instrumentsPlastic/rubber tubesRubber lids of any vial Used plastic drapes	Anything contaminated by blood or body fluids Body parts Any item which have been in contact with the patient Bandages, cotton Teeth (with/withoutfillings but without amalgam fillings)Dressings and swabsDisposables such as gloves,aprons,masks,drapes, contaminated wipes, throat packs Discarded crowns, bridges and cast partial denturesWaxes, gutta purcha points, absorbent pointsDisposable impression trays with impression material Acrylic partial dentures, complete dentures, denture teeth Plaster/ stone castsCheek retractors, tongue depressors, wedgesRubber dam material Plastic X-ray pouches(outer covering)Catheters(after draining)Unwanted laboratory specimensSuture materials without needle	Glass bottlesBroken bottles Discarded medicines Antiseptics, disinfectants (not contaminated by body fluids)Used or unused drug vialsCartridges and ampoules	Used or unuseed sharpsNeedles without syringes Scalpel blades Metal objects Metal matrix bands Broken metal instrument tipsBurs Endodontic files, broaches, reamers, spreaders,silver pointsOrthodontic metal brackets,wires,bandsSuture needles Broken/discarded ultrasonic tips Metallic bars, clasps from partial dentures Metal lids of vials All metalic dental implants related material

Table 2 Theproposed simplified biomedical waste segregation scheme for dental clinics13

Water test

The outer layer is designed to be waterproof.

Fold the mask such that the outer side forms a funnel and pour some water into it. The mask should be holding up the water properly.

Fire test

The middle layer is a filter, not a piece of paper. Therefore, if you were to light it with a flame, it WILL NOT catch fire.

Sequence of wearing PPE – Centre of Disease Control Guidelines ([Figure 5])

Gown

Fully cover torso from neck to knees, arms to end of wrists, and wrap around the back.

Fasten in back of neck and waist.

Mask or respirator

Secure ties or elastic bands at middle of head and neck.

Fit flexible band to nose bridge.

Fit snug to face and below chin.

Fit-check respirator.

Goggles or face shield

Gloves

Sequence of removal of PPE – Centre of Disease Control Guidelines ([Figure 6])

Outer Gloves (assume outside of glove is contaminated.

Gown (assume gown/apron front and sleeves are contaminated.

Goggles or face shield (assume outside is contaminated.

Mask (assume front is contaminated.

Remove the inner gloves.

Perform hand hygiene.

Waste Management

As directed by Central Pollution Control Board (CPCB), the guidelines for PPE are as follows

Goggles, face-shield, splash proof apron, plastic coverall, hazmat suit, nitrile gloves – RED BAG.

Masks (including triple layer mask, N95 mask, etc.), head cover/cap, shoe-cover, disposable linen gown, non-plastic or semi-plastic coverall – YELLOW BAG.

Summarisation of waste management in 2 tables.

Conclusion

The working area of a dentist, the dental office, is different from other health proffessionals in that there is a closer doctor patient interaction and the chances of infection spread is high. In these dark times, especially with every patient being a potential carrier for the novel coronavirus, proper precautions if not taken can result in cross contamination. So a proper maintanance of hygiene, a strict protocol along with great caution is the way to go forward in this proffession.

Source of Funding

None.

Conflict of Interest

None.