– Dr Snehal Kamble, Dr Shruti Gawande
Covid-19 (Corona virus disease 2019) is a RNA-based virus that came to light in December 2019 when China informed World Health Organization (WHO) of a rampant spread of pneumonia-like cases. On March 11, 2020,Covid-19 was declared as a pandemic, a public health crisis that is still having a rippling effect in every sector. Due to its implications, dental healthcare has faced several clinical, psychological and financial repercussions, having unforeseen consequences on dental professionals, patients and lab personnels. Unlike other routine dental procedures prosthodontic treatment demands multiple patients’ visits which throw a unique challenge to ensure bilateral safety and to avoid collateral damage at every visit. This article presents necessary recommendations regarding the prosthodontic dental treatment procedures with standards of care and infection control.
Keywords: Coronavirus, COVID-19, Dentistry, Dental treatment, Prosthodontics
The outbreak of coronavirus disease 2019 (COVID-19) in the area of Wuhan, China, has evolved rapidly into a public health crisis 1 and has spread exponentially to other parts of the world. The novel coronavirus belongsto a family of single-stranded RNA viruses known as Coronaviridae. 2 This family of viruses are known to be zoonotic or transmitted from animals to humans. These include severe acute respiratory syndrome coronavirus (SARS-CoV), first identified in 2002, and the Middle East respiratory syndrome coronavirus (MERS-CoV),first identified in 2012. 3
The Covid-19 virus, having diameter in the range of 100 nm, primarily transmits through person to personcontact and direct contact with respiratory droplets. 4 The word ‘corona’ is derived from its appearance as ‘crown-like’ while being observed under the electron microscope. 5 It primarily transmits through person to person contact and direct contact with respiratory droplets. Spread through asymptomatic carriers has also been recently documented and is one of the major reasons for creating fear and dilemma in the minds of dental practitioners. 6 The close proximity to oral fluids, aerosols and long incubation period of the virus, place the dental fraternity at a high risk of contracting and transmitting the virus. 7 Ministry of Health and Family Welfare (MOHFW), India has formulated specific guidelines and is playing a pivotal role to constantly update them with changing dynamics of disease. At present, only emergency and urgent procedures have been recommended to be taken up, with extreme focus on personal protective equipment and disinfection protocols.8 However, the fleeting nature of specialty-wise guidelines and overlap of recommendations given by various organizations; has convoluted its implementation in dental set up.9
The prosthodontic procedures especially need to be modified during the COVID times. The target population, comprising of the geriatric group with or without co-morbidities, post-cancer immunocompromised patients or patients with extra-oral maxillofacial defects requiring prosthetic rehabilitation, makes it imperative to lay down guidelines which are versatile and compliant by the patients and doctors as well.10,11
I) General Considerations
- Initial tele-screening of dental patients to identify suspected COVID-19 carriers
- Considering every patient as a potential asymptomatic COVID-19 carrier.
- Considering recently recovered patients as potential virus carriers for at least 30 days after the recovery confirmation by a laboratory test.
- Meticulous screening of even asymptomatic patients is important. Patients should be requested to fill out detailed questionnaire regarding COVID-19.
- Maintenance of proper record, address, contact details are of paramount importance. Since the incubation period of SARS-CoV-2 may extend over 2 weeks, a positive response to any of the above queries mandates deferring the appointment for at least 2 weeks.
- Additionally the patients should be encouraged to self quarantine at home and contact their primary care physician for tele-consultation. 11,12,13
- Those patients who seem fit for appointment scheduling should be advised to wear a surgical face mask and preferably come alone or with a single attendant at the time of their dental visit.
- Dental office and the waiting area should be well ventilated at all times along with spaced out seating of patients.
- Patients should be instructed to arrive on time for their appointments.
- Remove magazines, reading materials, toys and other objects.
- Schedule appointments to minimize possible contact with other patients in the waiting room.
- Use of contact less thermal screen and pulse oximeter device should be considered even if the patient answers no to the COVID symptoms questions. 11
- Use of pulse oximeter can be expanded in general dental office screening procedures during this pandemic. An oxygen saturation of below 90% is a good marker for some form of oxidative distress in the body. Use of pulse oximeters can help in screening of patients that might be asymptomatic but are actually having the disease.
- Patients should be instructed for hand sanitization and proper hand washing as soon as he/she enters the clinic.
- The prosthodontist in his clinic should ensure that entire team is well versed with the universal precautions.13
II) Prosthodontic Considerations
1) Removable prosthodontics: This includes fabrication of complete and partial dentures. Age has been documented as primary risk factor for increasing COVID-19 mortality rate, compounded with the presence of co-morbidities.14 Hence, a thorough medical case history is a must before starting any geriatric patient to evaluate risk versus need benefit. Completion of pending procedures must be given preference in comparison to starting of new cases to avoid unnecessary implications.
Chair-side protocol –
- Fractured prosthesis should be repaired by first disinfecting it thoroughly.
- Ulcerations or mucosal erosions can be handled through tele consultation by advising some analgesic and antiseptic gels for local application and discontinuation of the prosthesis for the time being.
- Mild smoothening of sharp borders can be advised with sandpaper if patient can't come to the clinic.
- Patients should be recalled in the clinic on strict appointment schedule if any further adjustment of the prosthesis is mandatory to restore its function.
- Denture adjustment should be done using a low speed micro motor.
- New prosthesis should be fabricated if it is affecting the systemic health of the patient.
- Primary impressions should be made in well-fitting stock trays and secondary impressions should be made in custom trays which can be discarded after obtaining the master cast.
- One step border molding can be done to minimize chair side time.
Laboratory protocol –
Record bases and wax rims should be adjusted on prior basis in order to avoid any modifications after insertion in the mouth. Care should be taken to minimize processing errors in lab and dentures should be remounted to adjust occlusion. This will ensure lesser follow up visits of the patient.
2) Fixed Prosthodontics: The fixed prosthodontics includes fabrication of crowns and bridges, inlays, onlays, smile designing, veneers, full mouth rehabilitation, post and cores etc. These are elective and aerosol generating procedures. So, adherence to strict precautions and disinfection protocols is mandatory. Digital impressions using intraoral scanners is safe alternative but the cost- benefit ratio needs to be taken care of. Papi et al. have compared digital workflow with conventional workflow and concluded that digital method reduces human contact at multiple steps thereby decreasing risk of transmission of virus, saves time and improves efficacy.16
Chair side protocol-
- Use of rubber dam and high vacuum suction are recommended during tooth preparations where supragingival margins are planned.17 This effectively wipes out most of the blood and saliva contaminants; also keeping the viral load to a minimum.
- Clinicians should avoid any undercuts and underreduction in their tooth preparations to prevent lab errors and multiple appointments.
- Shade matching should be preferably done by digital spectrophotometers and consent of patient should be taken.
- Intraoral photographs can be sent online to the laboratory to avoid any shade mismatch.
- Removal of fractured and faulty prosthesis using crown removers is advisable.
- Recementation of the dislodged prosthesis can be done, whereas adjustment of the temporary crowns should be done extra-orally using a micromotor.
- The dental tools such as air rotor and burs should be autoclaved as per manufacturer'sinstructions.
- Additional steps include working position of dentist at 11–12 o’ clock, reduced air pressure in 3-way syringes, full protection PPE for both doctor and assistant, use of anti-retraction hand pieces and disposableburs.5
- Frequent rinsing and spitting should be prohibited.
Crown & bridge impressions and trays need to be carefully disinfected/autoclaved.
3) Implant surgery and it’s implications in prosthodontics
Implant dentistry is the most fascinating and earning division for prosthodontists these days. Deferring patients for placement of implants can lead to big financial and mental trauma to the dental and lab personnel. But implant treatment planning involves multiple dental visits which, along with use of surgical aerosol generating hand pieces, call for extreme precaution in regard to disinfection and infection control. Following recommendations are suggested by authors though personal discretion is a must.
Chair side protocol-
- Healthy patients with no other co-morbidities can be taken up based on CBCT and virtual planning.
- During surgery, slow speed drilling with sharp drills is preferable.
- Intermittent external irrigation along with high volume suction should be done.
- Use of ultrasonic devices and piezoelectric surgery should be minimized; whereas use of osteotomes should be encouraged in order to reduce aerosol formation.18
- Immediate implants with immediate loading should be taken up wherever indicated as they require lesser time number of visits.
- It is advisable to avoid complex full mouth procedures.
- Digital impression with scan bodies is suggested as an alternative to conventional impression making.
Implant impressions and components need to be carefully disinfected/autoclaved before reusing them.
4) Handling dental impressions:Dental impressions are a high risk source of infection transmission and should be handled with care to minimise transmission to lab personnel – which is also the duty of the dentist.
- Autoclaved stock trays should be used and material should be loaded carefully to avoid gag reflex.
- Impression should be kept under running water avoiding direct flow over tissue surface to avoid losing surface details.
- Spray disinfectant can be used for chair side disinfection followed by packing in zip lock bags before sending the impressions to laboratory for pouring.
- Work authorization forms should be sent in separate zip lock bag. 19
Recommendations given in Table 1 should be followed in the lab for disinfection as per the material.4,6
In these extraordinary times, extraordinary measures need to be taken by all dental professionals. Prosthodontists, assistants, other essential supporting staff, and patients are at a potentially higher risk ofCOVID‐19 infection during prosthodontic treatments. Dental team needs to update their knowledge and learn the use of new approaches such as Tele‐dentistry whenever possible to manage patients and to avoid the risk of cross infection. The chances of contracting COVID‐19 are very low to very high while instituting holistic prosthodontic care to the patients depending on the treatment protocols adopted in the clinics.
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