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Dentistry In Covid-19 Pandemic

              It was first diagnosed in Wuhan, china 31, DEC 2019 as a Pneumonia like disease. But soon it revealed its true identity as one of the most dangerous member of Coronavirus (nCoV) family. Coronavirus (nCoV) are a large family of viruses that cause illness ranging from the common cold to more severe diseases.  But this novel coronavirus (nCoV) that has not been previously identified in humans is mutating very quickly  as compared to its other family members like SARS, MERS.

        A recent clinical study indicates that 29% out of 138 hospitalized patients with CoRoNa Virus-infection in Wuhan, China, are healthcare workers [Ref].

Routes of transmission of nCoV Virus in Dental Clinic

1. Airborne Infection:  As the world is at stake by the effect of Wuhan virus, dentist and the dental staff remains at the highest risk to catch nCoV infection during routine dental procedures like RCT, crown cuttings, fillings etc.  In fact, dental clinics could be a dangerous place for the spreading of the disease to the community. This is well known today that nCoV possess human to human transmission, it is also present in the patient saliva. A lot of aerosol is generated during routine dental clinical procedures which can stay in the air for at least 2-3 hours. The transmission of nCoV through contact with droplets from talking, coughing, sneezing and aerosols generated during clinical procedures is expected and is at high risk.

       The origin of droplets can be nasopharyngeal or oropharyngeal, is usually associated with saliva. Larger droplets could contribute to viral transmission to subjects nearby and on the other side, the long-distance transmission is possible with smaller droplets infected with air-suspended viral particles.

      As in bronchoscopy [(Ref)], inhalation of airborne particles and aerosols produced during dental procedures on patients with nCoV can be a high-risk procedure in which dentists are directly and closely exposed to this virus. The Guidance for Healthcare Professionals from CDC and local governing bodies has been updated and it is subject to change as additional information on nCoV infection and transmission becomes available.

2. Contact Infection: A dental professional remains in contact with patient’s material and dental instruments which are usually contaminated with patient’s saliva or blood. Talking and coughing without mask can transfer the Virus from one person to another. Health professionals are required to maintain a well distance while talking to a patient and wearing masks is necessary for both of them. Handling of currency, card or prescription can also be a means of infection.

3. Contaminated Surfaces: Aerosols generated during dental procedures will settle on the instruments like dental chair, spittoon, nearby X-ray machine and other dental instruments, laptop, RVG’s, dentist chair, door handles, walls, clinics table, chair and the furniture present in the clinic and waiting areas. Each and every surface in the clinic can easily get contaminated through aerosol.

         Once contaminated with nCoV, the virus can persist on metal, wood or plastic surfaces for several days. These contaminated surfaces could be the major source of infection for several days. Both the health professionals and the patient will be at risk for several days if not cleaned well with alcoholic disinfectant.

Infection control in dental set-up:

         First of all, Dental professionals should be familiar with how nCoV spread, what are the symptoms of corona +ve patients, how to identify patients with Corona virus infection, and what extra-protective measures should be adopted during the practice, in order to prevent the transmission of Corona virus. Keeping in mind that the main source of Corona infection is aerosol and droplets infection, dentist should follow a strict rule of infection control.

1. Rescheduling the Patient: 

Temporarily suspend all non-urgent dental appointments until the crisis is over or health officials indicate that it is appropriate to resume. 

    QuestionWhy do we need to stop elective procedures?

   Answer: 1.We can’t reliably identify patients who are asymptomatically infected.

 2. Many dental procedures will generate aerosol that will increase the risk of infection.

3. Supplies of PPE kits for treating critically sick patients in hospitals is critically low. If we use these items for non-urgent care, we will be contributing to the risk of the front-line healthcare workers being left unprotected.

 Primary care dental triage should focus on the provision of the three as:
        a. Advice
        b. Analgesia
        c. Antimicrobials (where appropriate)

Only the treatment of Patients with dental emergencies are allowed.

Dental Emergencies (source: ADA)

  • Potentially life-threatening conditions that require immediate treatment to stop ongoing tissue bleeding to alleviate severe pain or infection
  • Uncontrolled bleeding 
  • Cellulitis or a diffuse soft tissue bacterial infection with intra or extra oral swelling
  • Trauma involving facial bone compromising patient’s airway
  • Severe dental pain due to pulpal inflammation not responding to medicines
  • Pericoronitis or third molar pain
  • Surgical post-operative osteitis, dry socket dressing changes
  • Abscess or localized bacterial infection resulting in localized pain & swelling
  • Tooth fracture
  • Dental trauma with avulsion/luxation
  • Dental treatment required prior to critical medical procedures
  • final crown or bridge cementation if the temporary restoration is lost, broken or causing gingival irritation

2. Patient Education and Counseling:

       Display a chart in the waiting areas showing CoRoNa Virus symptoms and mode of spreading. Ask each patient to read and then do a little counseling of patient if he/her have any symptoms of Corona virus or have any travel history or they have been in contact with a person who either had a travel history or they are found corona positive or quarantined recently within 20 days. Get a signed consent for their answers. It’s health professional’s responsibility to find whether patient is telling truth or lying. Because some patient tries to hide such information or they think they don’t have or can’t have corona or other infection.

3. Hand Cleaning Recommendations:

All the dentists and supporting staff should wash their hand thoroughly with soap and water and follow up
with alcohol-based hand sanitizers, before and after every patient screening or interaction. Surgical scrubbing of hands is recommended. Disposal of gloves to be done routinely as per protocol.

hand-cleaning-cdc

CDC and WHO recommendations for cleaning hands. Staff and doctors should avoid touching their face specially the ear, nose and mouth.

4. Safety Guidelines for Dentist & Dental assistant:

  1. Wear mask: Patients who are asymptomatic may spread the CoRoNa Virus infection. Hence it should be assumed that all patients coming to the dental clinic can transmit disease.

                    a. N-95 mask – Risk of infection is low

                    b. Surgical mask – Risk of infection is moderate

2. Personal Protective Equipment (PPE): PPE refers to a wearable equipment that is designed to protect DHCP (Dental Health Care professionals) from exposure to or contact with infectious agents. PPE include gloves, face masks, protective eye wear, face shields, and protective clothing (e.g., reusable or disposable gown, jacket, laboratory coat).

CDC and WHO has issued guidelines for how to wear and remove PPE safely and dispose them.

5. Dental Treatment Considerations:

1. Carry out only one dental treatments in a single operatory. If possible, use separate clinical areas for Aerosol and Non-aerosol dental treatments.
2. Use 1.5% hydrogen peroxide or 0.2% povidone iodine as a pre-procedural mouth rinse. Chlorhexidine mouth rinse is not use full for Covid-19.
3. Preferably use extraoral dental radiographs such as panoramic radio graphs as alternatives to intra oral radiographs during the outbreak of COVID-19, as the latter can stimulate saliva secretion and coughing. Avoid RVG as it can’t be autoclaved or completely cleaned with alcohol rub, until more detailed information is present about CoRoNa Virus.
4. Reduce aerosol production as much as possible. DHCP should prioritize the use of hand instrumentation. Use micro motor hand piece in place of airotor as micro motor causes minimum aerosol generation. Autoclave hand piece after each use. 

5. Use 0.2% povidone iodine in chair-side bottle to minimize the infection. 

6. Use rubber dams along with high vacuum suction if an aerosol producing procedure is being performed to help minimize aerosol or spatter.
7. Dentist should use a 4-handed technique for controlling infection.
8. Dental care teams should “minimize the use of a 3-in-1 syringe as this may create droplets due to forcible ejection of water/air.”
9. Restrict the number of para-dental staff and patients who enter the clinical as well as waiting area of the clinics.

6. Guidelines for Clinic area and Waiting area:

Operatory should be well ventilated with negative pressure for rapidly cleaning of the inner environment. Pre-operative and Post-operative Infection Control protocols should be followed and regular fumigation of clinics should be carried out.

1. Flush all water lines for 30 seconds before attaching handpieces to the lines.
2. If an ultrasonic scaler is to be used, flush the scaler line for 30 seconds before attaching the tip.


It has been shown that water bacteria multiply in the water lines, especially during periods of inactivity.


3. Cover the following items with PLASTIC BAGS of appropriate size (large, small) if they will be touched at any time during treatment.

  • The Dental unit is bagged with a large bag (Don’t bag the handpieces), tied
    loosely at the side.
  • The chair back is bagged with a large bag.
  • The computer keyboard is covered with a small bag.
  • The curing light tip is covered with a disposable plastic sheath.
  • The arm that holds the suction is covered with a small sheath.

4. Cover the following items with PLASTIC WRAP (cover all strips) if they will be touched at any time during treatment. Light handle(s)

  • Light switch(es)
  • Ultrasonic scaler hose (if used) (2 feet from coupling)
  • X-ray viewer box light switch
  • Computer mouse
  • The adjustment handle under the seat of the operator chair

Any surface (horizontal or vertical) within three feet of the patient’s mouth is considered contaminated after providing treatment that produces aerosols or splatter. Covering surfaces with impermeable barriers eliminates the need for disinfection of these surfaces after each treatment. Surfaces that are difficult to clean must be covered or wrapped with barriers such as impervious paper, clear plastic film, or bags.


5. Set up all items to be used in the planned procedure. Instruments and items that may or will contact the patient’s mucous membranes must be disposable or sterilized prior to use. Sealed and sterile instruments/equipment should be used. Open each package aseptically.

6. If a bridge, denture, or other prosthesis that has been fabricated is to be inserted into the patient’s mouth, be sure that it has been adequately disinfected.

7. Individual portions of material should be dispensed ahead of time and placed on the working tray. This includes materials provided in a bottle, tube or jar. Materials supplied in bottles (e.g. hemostatic agents, adhesives) should be dispensed into a cup or into a disposable dappen dish. Items provided in a tube (e.g. impression material) should be dispensed onto a mixing pad, sterile gauze, or a glass slab. Dispensing materials ahead of time prevents contaminating the outside of bulk containers

8. Equipment that is carried to the operatory from the dispensary must be bagged and placed in the correct area. Light-curing units must have their on/off switches covered with cover-all strips and the area of the light pen/gun that will be held must be covered with plastic wrap. Ultrasonic scalers must be covered with a large bag and the scaler handle must be covered with plastic wrap or a small bag.


Shared items and equipment are potential sources of cross-contamination. Items that have been contaminated must be disinfected or sterilized before being used on a different patient.


9. Cabinet’s door and drawers must be kept closed during treatment to avoid contaminating the contents.
10. All personal belongings must be kept in a locker room. Personal belongings are not permitted at the dental unit during regular clinic hours.

Protocols During Patient Care

Sterility of Instruments:

          All the instruments like High-speed handpieces, nose cones, contra angles, low-speed motors, motor-to-angle adapters, and all other autoclavable dental instruments must be autoclaved before use in the mouth. “Cold sterilization” is not an acceptable method for general-purpose sterilization.


Blood, saliva, or gingival fluid may contaminate the exterior and interior of the handpiece and only heat treatment can assure the killing of all microbial contaminants.


Damage to Gloves during Treatment:

      If a glove is torn during patient treatment, both gloves must be removed, the hands washed, and a new pair of gloves put on. If the tear was caused by an instrument used in an invasive procedure, replace the instrument with a STERILE one.

Dropped Instruments:
       An instrument that is dropped must not be picked up and reused. If the instrument is essential for the procedure, either it must be sterilized or a sterilized replacement instrument must be obtained.

Clean-up of Operatory after Treatment

After Patient Treatment
Following patient treatment, use the following protocol, in the order given, for cleaning-up:
1. Write up all forms and record entries  relating to the treatment.
2. Complete all entries in the computer.
3. Remove gloves.
4. Wash your hands immediately.
5. Dismiss the patient.
6. Put on heavy-duty, nitrile rubber gloves.


Nitrile rubber is more puncture resistant than latex. Nitrile gloves may not prevent a puncture in your skin but they may prevent blood or other contamination on the instrument from entering the wound.


7. Discard needles and any disposable sharp instruments (e.g. scalpel blades, suture needles, broken instruments, endodontic instruments, used burs, orthodontic wires, and any item that could puncture skin) using forceps into the rigid biohazard (sharps) container at your unit.
8. Carefully remove all disposables from dental unit and discard them into a rigid waste receptacle. 
9. Place handpieces into the transportation cassette and place them to the side.
10. Place all the dental instruments back into their cassettes in the correct order by removing all composite, and other non-biologic waste.
11. Disinfect all portable equipment and supplies with Cavicide disinfectant as follows: SPRAY with Cavicide disinfectant and WIPE clean of visible debris using paper towel. Then SPRAY again with Cavicide and KEPT MOIST for at least 5 minutes.
12. Remove un-used dental instruments from the sterilization pouch.
13. Return the dental instruments, handpieces and bur cassettes to sterilization.
14. Remove ALL barriers, one at a time, from the unit and any portable equipment and discard into the plastic waste bag.


All surfaces within a 3 feet radius of the patient’s mouth are considered contaminated and are treated as clinical contact surfaces. All disinfectants take time to act—often 5
minutes or more. Using them on surfaces as you would use a furniture polish will not achieve disinfection. The surface must be wetted and it must remain wet for the full length of time required.


15. Discard the paper towels and napkins.
16. Flush all vacuum lines with tap water to prevent drying of blood and debris in the lines.
17. Remove gloves and discard.
18. Wash hands.
19. Remove face mask by grasping its elastic band at a point behind your head and bring the band over the top of your head.
20. Remove safety glasses or face shield by using two hands to grasp the earpieces just in front of the ear and lifting them off. Remove face shields by grasping behind the head, if it is the style that has a band encircling the head, or in a manner similar to safety glasses.
21. While wearing gloves, wash safety glasses or face shield with regular soap and water and rinse well. Disinfect by spraying with Cavicide disinfectant and keeping the surfaces wet with the disinfectant for 5 minutes. 
22. Remove gown or PPE as described abovein pic such that your hands do not touch the contaminated outside.
23. Wash hands.
24. If you leave the clinic area any time after beginning treatment of a patient, all personal protective equipment must be removed and changed; i.e., gloves, mask, safety glasses or face shield, and head covering, and clinic gown.

Disinfection

Disinfection of Hard Surfaces
Surface disinfection is done using the Cavicide disinfectant.


Glutaraldehyde based compounds should not be used for surface disinfection due to their potential toxicity!


1. Clean the surface using the Cavicide and paper towels.
2. Spray the surface liberally with the Cavicide and make sure it remains moist for at least 5 minutes.
3. Dry the surface with paper towels or allow it to air dry.

4. Spray with Cavicide the door handles, doors, table, chair, walls where patient have been in contact or passed through. 

Disinfection of Equipment:
Chemical Disinfection: Glutaraldehyde or Cavicide is used for the disinfection of instruments and equipment that cannot be sterilized or will not penetrate tissues. Heavy-duty, nitrile rubber gloves and protective eyewear or face shields must be worn when mixing and/or using chemical sterilants or disinfectants.


GLUTARALDEHYDE CAN CAUSE BLINDNESS AND SKIN SENSITIVITY and
THE VAPOR IS TOXIC.


1. Put on a pair of heavy-duty, nitrile rubber gloves and protective eyewear.
2. Clean and dry all instruments to be disinfected.
3. Immerse them for at least 5 minutes in the glutaraldehyde or Cavicide solution. Timing begins when the last item is added to the solution. When an item is added to the solution, the solution and everything in it become contaminated. Therefore, timing begins each time an item is added. Disinfection of dirty items should not be done with cleaned instrument. As, soaking dirty items in disinfectant will reduce the hazard present during the later cleaning of these items, but they must NOT be considered disinfected.
4. Following disinfection, items must be rinsed with water, dried, and stored in a manner such that they will not become contaminated.

Autoclaving: Heat resistant instrument should preferable be autoclaved. Clean all the instrument and put them in separate pouches and place them in autoclave. According to manufacturer instructions autoclave it. 

Above mentioned protocol is for a routine clinic Disinfection but in the time of this Covid-19 Pandemic these procedures should be repeated after each patient.

References:

Short forms:

nCoV- Noval CoronaVirus or Covid-19

PPE-Personal Protective Equipment 

DHCP- Dental Health Care  Personal

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