Dental Tribune India

Prevention of cross-contamination in dental clinics: Practical suggestions from Dr Ajay Kakar

By Dental Tribune South Asia
April 26, 2020

Dr Ajay Kakar, a periodontist from Mumbai well known for his innovative approach to dentistry and also known as a pioneer in the use of technology and software for dental practice management in India gives his practical recommendations to prevent cross-contamination in dental clinics. He was one of the earliest (the first in India, probably) to make a No-Spittoon dental clinic.

Dr Rajeev Chitguppi’s thought and suggestions on the use of Povidone Iodine in the DUWL (Dental Unit Water Line) to become part of the aerosol and deal one more body blow to microorganisms which could make their way to the aerosol and splatter generated in dental clinics are pertinent and thought-provoking.

In all probability, the povidone-iodine should not cause any major problem in the water line or the air rotor handpiece. But this would also mean that a two-bottle system would have to be created with one bottle for the air rotor and one bottle for the three-way syringe. We cannot always have the povidone-iodine in the three-way syringe as it will impact bonding dentistry. Of course, it has to be checked if the povidone-iodine will clog or corrode or damage the cartridge of the air rotor handpiece or a slow motor in case it is being used with the waterline.

There are some very basic common sense and rational suggestions, which if implemented, will bring a very high level of protection against cross-contamination. These thoughts are based on certain fundamental issues that arise in a dental office and have been formulated to combat these issues at different levels. The main goal is to maintain a contamination-free dental office and ensure no microbial/viral load during treatment and after treatment.

To start with, it is assumed that the dentists and the staff are not carrying any clinical or subclinical microbial loads. If they are, they should start working only after reaching a status of health. Hence the only possible means of contamination is via the patient. The patient can theoretically transmit to the staff in the office or can leave behind a lesser microbial/viral load on the chair, door, bathroom and other places the patient contacts during the visit. Hence the approach has to be two-pronged – one to ensure that there is no contamination of the dentist and staff and the second is to cleanse the operatory and the office once the patient has left.

A. Cleansing the dental office

A very standard and simplistic routine should be to add a disinfectant to the water when the office floor is cleaned in the morning. This is the first level of defence. The next would be to spray all potential hot points like the main door handle. Front desk table, chair armrest, chair pillar etc. etc. with another disinfectant. This spraying protocol should be prior to starting work and in the entire dental office when closing up. This is a twice a day protocol.

The active agents which can be used for the above are as follows:

1. Floor cleaning – Lizol can be used which is a branded product. It contains benzalkonium chloride and hydrogen peroxide. A much more economical solution but as effective is a product called Benzyl Septol. A 5 litre can cost only about Rs 375. Optionally one can use generic Benzalkonium chloride which can be sourced from a chemical shop but this will only save about 35 to 30 rupees. A bucket of water should have about 100 ml of Benzyl Septol added to it for effective removal of latent microorganisms.
2. Mop floor with water treated with Benzyl Septol.
3. Above the floor surfaces – One of three products can be used for this. Since this is only twice a day procedure, the recommendation is to use 1% sodium hypochlorite in a spray bottle. Sodium hypochlorite, even at 1% concentration, has an odour which is not very pleasant and hence is not suggested for in-between patients usage.
4. Spray hot spots with sodium hypochlorite prior to opening and while closing

Fig 1 A high-quality spray can which can be used for Sodium Hypo as well as Benzylalkonium

5. Between patients, it is recommended to use a Benzalkonium spray. This is effective and does not have any smell at all. It should be used on all surfaces which could have settled microorganisms. After spraying and waiting for a few minutes it is wise to spray the area again with alcohol. One could use any of the hand scrubs available. A highly recommended and very affordable but as effective as any is a product called “Sarvanol”. It is basically propanol and ethanol and is an excellent hand disinfectant in the office and doubles as a cleaner for the benzalkonium which dries on the surfaces. In fact, the Sarvanol becomes a second safety measure against cross-contamination from surfaces.


Spray hot spots between patients with benzalkonium, wait 5 mins and cleanse with alcohol.

The above three steps using three different products is one of the means to control and stop cross-contamination in the dental office. The three products recommended are “Benzyl Septol”, “Sarvanol” and 5% Sodium Hypochlorite. Dr Adwait Aphale has to be given due credit in sourcing these extremely effective but at the same time, very affordable products which provide an overall defence against stagnant micro-organisms. This includes bacteria, virus and fungi.

B. Treating the patient

While treating the patient the attempt should be to reduce the bacterial/viral load to a minimum and to ensure that there is none or a bare minimum of contamination created from the patient's mouth since dental therapy is only delivered to the oral cavity. There are a number of steps that should be done which will ensure and prevent cross-contamination. Dental therapy usually lasts from maybe 20 mins for a consult to about two hours for most procedures. There are some extensive procedures that may last longer. For longer procedures, the patient should be given a break and the same protocol followed during the break as would be done between two patients.

1. Mouthrinses:

The first step that should be done is to ask the patient to do two mouth rinses. The first one can be a 0.2 % chlorhexidine digluconate mouthwash (without dilution and without a flavouring agent) or an essential oil mouthwash like Listerine. There will be no harm done if the patient rinses with both of these also. This rinse should be followed by a rinse with povidone-iodine. Betadine is one of the best products available for such a rinse. This simplistic protocol will bring down the oral bacterial/viral count down drastically and literally make the oral cavity free of the organisms for a period of 1.5 hours.

The steps can be summarised as
a. Mouth rinse with Chlorhexidine digluconate and/or essential oil mouthwash
b. Mouth rinse with povidone-iodine

2. Scrubs:

Subsequent to this, the patient once seated on the chair and draped should be scrubbed extra orally first and then intraorally with povidone Iodine. This will further ensure that any remnant organisms are also almost eliminated.
a. Extraoral scrub with povidone Iodine
b. Intraoral scrub with povidone-iodine

C. Initiating the treatment:

The next step is to initiate the treatment. Dental procedures require the use of high-speed rotary instruments most of the time. Scaling, a very common procedure recommended for almost all patients requires using a vibratory tip with an accompanying water spray. The main issue here is that of the generation of an aerosol during these procedures and the constant spitting out of the collected water by the patient into the adjacent spittoon. This aerosol is prone to contamination from the patient's mouth since the work is being done with accompanying pressurised water and air. Even though the available microorganisms have been controlled significantly with the pre-procedural mouth rinse, it would be a good idea to control the aerosol and the splatter caused by the ejection of liquid by the patient into the spittoon. Even though a lot of discussions revolves around the aerosol which could get contaminated, the splatter is actually a bigger source of potential cross-contamination.

One of the first steps that should be done is to make a lifestyle change in the working environment of the dental office. The spittoon should be eliminated completely. This may sound a bit difficult but it is the most effective means of eliminating cross-contamination. Of course, there are a number of other benefits of eliminating the spittoon, but those are not being discussed in this article. Here the focus is on cross-contamination. Once the spittoon is eliminated, it by default makes it mandatory to have a high vac suction unit. It is impossible to do any dentistry without a spittoon if there is no high vac suction.

1. Spittoons and Suctions:

The high vac suction has a broad tip and it pulls in ambient air and almost eliminates the aerosol at the source during all air rotor work and scaling procedures. When used effectively by the chairside assistant, it almost eliminates the contaminated aerosol from being generated. The problem is resolved at the inception phase itself. Excellent high vac suctions are available from Durr Dental and also from Katani and Ajax which is marketed in India by Prime Dental Products.

The first two steps in achieving the goal of a cross contamination-free dental clinic during dental treatment are
a. Elimination of the Dental Spittoon
b. Mandatory use of a High Vac Suction in all dental procedures

2. Extraoral Suction 3D:

To build a further line of defence a relatively new device can be added. This is a very simplistic wide funnel tip that hooks onto the cheek retractor and is connected to the high vac suction line at the other end. This will further trap any aerosol that escapes the high vac suction tip at the point of work. It should be mentioned that there are some videos which demonstrate the use of this extra-oral device but without an intraoral suction tip being used. This is not the correct way of trapping the aerosol. As mentioned before it is mandatory to use a high vac suction intraorally. The extraoral device should be the second barrier and not the primary barrier. This nifty piece of equipment called the Suction 3D is highly recommended.

3. Rubber Dam:

The next line of defence in the prevention of cross-contamination is the use of a rubber dam whenever possible. A rubber dam effectively isolates the tooth/teeth being treated from the rest of the mouth and thus prevents any cross-contamination. The only problem is that the rubber dam cannot be used for all dental procedures which generate an aerosol for eg. scaling, occlusal adjustment. The rubber dam does not eliminate the aerosol. It cannot. It is just a barrier. But it eliminates contamination of the aerosol, thus rendering it harmless.

Recommendation: Use a rubber dam is recommended dental procedures.

4. Personal Protective Equipment (PPE)

All the above is done only for patients who are not having any infectious disease symptoms. If the patient reports any cough, cold, sneezing or fever the patient has to be deferred and sent to the physician and to be treated dentally only when the infectious phase is over.

It is also assumed that the dentist and the assistant are suitably attired and using disposable gloves, masks, eye protection, an apron and a face shield during all procedures (PPE).

D. Dental clinic atmosphere and ambient bacterial/ viral/ fungal control

Maintaining high levels of hygiene standards in a dental office is the norm and all the steps suggested in the cleansing of the clinic are major processes in achieving the desired goal. To further consolidate and ensure a contamination-free dental clinic there are two pieces of technology which play a major role. The first one is a negative ion generator machine. This is a technology which has been around for two or three decades but has reached an optimum level of functionality and effectivity only of late. This machine in the appropriate power output generates millions of negatively charged ions and releases them in the ambient air. These negative ions attach to the cell walls of ambient bacteria and lyse them. They achieve a more or less same effect on the fungi. They also attach to glycoprotein receptors on viruses and neutralize them rendering them ineffective. In short, if sufficient negative ions are generated in an enclosed space, within an hour space is 99.7% free of bacteria/virus/fungi. If the clinic has already implemented the previously mentioned steps the potential contamination is down to very minimal or non-existent levels. A negative ion generator in the clinic is the icing on the cake. The microbiological effects of this technology are very well documented and no attempt is being made to enumerate and explain in detail the mechanism of action of such a machine. It suffices to say that it works and enough evidence is available in the literature in the medical world. If it works in general medicine, it will naturally work in general dentistry. This begs the question of where is such a machine available. It is indeed a great boon that one such machine is available and produced in India.

1. Negative Ion Generator:

Scietech negative Ion generator covers an area of about 1000 sq feet in achieving sterilization of the ambient air.

It is the “Scitech” and an outcome of the Dept. of Technology of the Govt of India. It is manufactured in Pune and costs around Rs 50,000/- It does have a significant GST as part of the cost. Considering the prevalent conditions, it would be great if the central govt could waive off the GST on this equipment. It is highly recommended. It should also be pointed out that there a number of low cost, home use negative ion generators for home use.

This would not be recommended as the power and ion generation capacity has to be sufficient to achieve the desired results. The Scietech negative Ion generator covers an area of about 1000 sq feet in achieving sterilization of the ambient air.

Recommendation: Install a Scitech Negative Ion Generator.

2. HEPA filters:

Even though the above steps have ensured a very highly disinfected clinic and eliminate all probability of cross-contamination there Is one last recommendation. This is like an additional nail in the coffin of cross-contamination after the last nail was already placed. Operation theatres have to be completely sterile because of the nature of surgical work. OT’s usually have what is known as a HEPA filter air cleaning unit. These are large units which are embedded in the architecture and layout of the OT. Technology has made it possible for manufacturers to develop smaller self-sustained units which effectively work for smaller rooms.

The HEPA filter is usually a three-layered filter through which the air in the room is being constantly recycled. This filter traps all bacteria/virus/fungi and it is usually bathed in UV radiation which kills/attenuates the bacteria/virus/fungi. It would be a great idea to install such portable units in dental operatories. This will surely ensure the elimination of all possible sources of cross-contamination. A very good unit is the one sold by a company called O-ION. This company is based in the USA and the unit would cost inside Rs 10,000/- Doshi Marketing Corporation, Mumbai is in the process of importing these units into India. A HEPA filter unit will be the ultimate protection in this multi-layered attack on cross-contamination.

Recommendation: Install a portable HEPA unit in the operatory.


All of the above are practices that should be incorporated in any dental clinic to ensure the prevention of cross-contamination. These will work for all infectious situations, be it bacterial, viral or fungal. And yes, it will effectively work on the entire range of COVID strains. It is assumed that all of the above will also generate biomedical waste which should be disposed of following the proper protocol and should not be included in general household and office waste. It is also assumed that the dental clinic uses all standard protective gear and uses ultrasonic cleansers and proper autoclaving protocols for all instruments and equipment.
The above bulleted bold points will ensure very high levels of infection control and the elimination of cross-contamination and should be always followed and implemented.

Author: Dr Ajay Kakar (Periodontist & Implantologist)

Dr Ajay Kakar completed his BDS (1981), MDS in Periodontics (1985) from Nair Hospital Dental College, Mumbai.  He lectures extensively in India and around the globe while maintaining an exclusive Perio and Implants practice in Chembur, Mumbai. Dr Kakar has served as the secretary (2011- 13) and president (2015 -17) for International Academy of Periodontology. He is passionate about electronics and is an avid software developer. He created BITEIN - the first Indian dental internet portal in 1998. He has also written a comprehensive dental administration and imaging software system. Currently, he manages the international affairs for SMYLIST® smile designing system and works extensively to build more research-backed evidence for the same.


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