Logic and simplicity of infection prevention in oral care practices - Orientation on the Infection Prevention guideline in oral care practices

Infection prevention is, as indicated earlier, possible to prevent infection. If contamination can not be avoided, it is important that as few viable micro-organisms as possible be transferred. In order to work safely, the contamination sources must be detected and determined.

Logic and simplicity of infection prevention in oral care practices - Orientation on the Infection Prevention guideline in oral care practices
Infection prevention is, as indicated earlier, possible to prevent infection. If contamination can not be avoided, it is important that as few viable micro-organisms as possible be transferred. In order to work safely, the contamination sources must be detected and determined.

Logic and simplicity of infection prevention in oral care practices


Infection prevention is, as indicated earlier, possible to prevent infection. If contamination can not be avoided, it is important that as few viable micro-organisms as possible be transferred. In order to work safely, the contamination sources must be detected and determined. The contamination routes are then visualized. On the basis of this, measures can be taken, so that the transfer is preferably completely blocked or otherwise cut off or made less risky. This can be achieved by reducing the number of viable micro-organisms transferred.


In the fight against viable micro-organisms, it is essential to know that:

  • Microorganisms are invisible;
  • Microorganisms can not move actively;
  • Microorganisms can move passively in air and water.


These three simple properties actually dictate in full how the healthcare professional should proceed.


This is followed by a logical arrangement of topics related to infection prevention in oral care practices, followed by elaborations of appropriate measures.


Safety for persons in oral health care concerns:

  • Patients;
  • Employees oral care practices;
  • Third parties.


Contamination sources in oral care practices:

  • The patient;
  • The team;
  • The unit water.


Contamination sources in oral care practices:

Direct contamination route by: 

  • Direct skin mucous membrane contact (porte d'entrée through uncovered wounds, or via the eye mucosa in case of a spattering accident);
  • Coughing (both from patient to team and vice versa (!));
  • Puncture accidents.


Indirect route of infection (from patient to patient) by: 

  • Contaminated aerosol;
  • Contaminated surfaces (lubricating contamination);
  • Contaminated instruments (cross-contamination).


The necessary reduction of the number of microorganisms to prevent infections varies per type of micro-organism and depends, among other things, on:

  • Attack force (virulence) of the microorganism concerned. Child diseases can be transmitted with relatively few micro-organisms;
  • Circumstances during the transfer; elapsed time, temperature, humidity or, for example, the presence or absence of nutrients for the micro-organisms;
  • Host factors:

- The place of contamination (porte d'entrée);

- Physical condition;

- Age;

- Current immune ability.


Approach safety persons

A. Patient safety requires, among other things, good personal hygiene of the health care workers. This includes:

  • Short nails (without nail polish or nail gel);
  • Tied or attached hairs;
  • A short-cut beard or mustache;
  • No rings, bracelets and wrist watches;
  • Jewelry in piercings that are vulnerable due to location or shape must be removed.


As a practical explanation of this section, here are a few points, so that the measures are tightened up, supplemented (!) Or clarified: 

  • The use of examination gloves is not mentioned in the summary of the KNMT as a protective measure for patient safety. Yet this is certainly a factor of significance in this perspective. Bare hands can be sufficiently disinfected for work with clean instruments and for example taking the telephone, but on contact with the (wet) mouth cavity, microorganisms that stop under the nails and in deep skin folds can move to the oral cavity. An ever-published variant of 'spray can gloves' (analogous to aerosol patches) is therefore forbidden.
  • Use of a mouth-nose mask is also not mentioned in the KNMT list. In the case of colds of the therapist, this will certainly contribute to patient safety. The mask must always be worn over the nose, if only because the Staphylococcus aureus from the nose poses a risk of contamination, apart from cold viruses. The mask must also close properly, so do not let the underside hang loose, or even cut the bow ribbons on the underside

A Incorrect mouth mask worn should be worn over the nose. B Incorrect mouth mask, must be fastened with all straps


  • The hair must be well cared for and put up or tied up, as stated in the guideline. When long hair is only tied up, the 'ponytail' at a certain length can undesirably come into contact with the (infected) treatment environment of the patient or possibly also with the patient himself. This has created an indirect contamination route. Therefore, for long hair, it should apply that bonding as a measure only satisfies when the tied-together hair does not reach lower than the shoulders. With a longer ponytail, the hair should always be put on

A Long hair in ponytail can spread contamination. B Stowed long hair is safe for patient and employee. C Loose bangs get contaminated by contact with mouth-nose mask


  • For a long pony, the loose hairs invite to wipe them out of the face with contaminated gloves. The hair can also be in contact with the infected mouth-nose mask or the infected protective goggles
  • The guideline states that a piece of jewelry in a piercing should be removed when the jewelery is annoying when carrying out hygiene measures. An image as an example of such a jewel in a (subcutaneous) piercing is added here


A Subcutaneous piercing is an obstacle to proper cleaning of the arms. B Remove jewelery from the piercing. C Open connection must always be covered with waterproof plaster


  • As an added safety measure, adequate protection against puncture, splash and cut injuries is necessary to ensure safety on the work floor. Sharp dynamic instruments, such as an ultrasonic angle piece with mounted tartar tip, are therefore only connected when they are actually in use. Before and immediately thereafter an ultrasonic angle piece is therefore always disconnected. The slogan that goes with it reads:


Incorrect to leave ultrasonically coupled


The ultrasound is always finished, except when it is on.


  • It is strictly forbidden to adjust the operation lamp with an instrument in hand. Control over the instrument can easily relax and it will not be the first time that a patient is injured by a (contaminated (!)) Device that slips from the hand of the practitioner.
  • Eye protection is certainly an effective measure for patients that is used in more and more oral care practices. A patient does not want any splashes and / or pieces of tartar in his eye during mouth cleaning! Although it is patient-specific material, it is in the wrong place and can cause an ugly infection



Comfortable eye protection patient


  • The disinfection of received technical work is also a measure that benefits the safety of patients.
  • Vaccination of health care workers also serves the safety of patients. After all, there is no risk that an employee who does not (yet) have any symptoms of disease is already very contagious. It can also be prevented that a 'tough' employee who is in fact ill (and therefore very contagious) is still at work. Apart from vaccination against diseases with a possible serious course of action, influenza vaccination will also prevent the latter situation in particular.
  • Finally, of course, all measures play a role that are identified in the approach to indirect contamination routes.

​​​​​​​B. Safety of employees in dental practices can be achieved through the simple and consistent application of: 1) gloves, 2) mouth-nose mask, 3) protective glasses, 4) work clothing, 5) work shoes, 6) safety policy on puncture and splash injuries, 7) vaccinations.


C. Third-party safety concerns the group of persons such as supervisors, interpreters, other family members who do not need to be treated by themselves, dental technicians and technicians or software packages. Measures to ensure their safety include safe walking routes, television screens in the waiting room instead of tumbled waiting room literature, no fabric upholstery on waiting room chairs and toys that are easy to clean. Finally, disinfection of outgoing engineering work also includes safety measures for this group of people.


Approach to direct contamination routes

Naturally, the first general measure applies: avoid (hand) contact with contaminated material. A small number of clinical procedures can be used in accordance with this so-called no-touch technique. This could, for example, be applicable when fitting impression trays. However, if contact is unavoidable during treatment or otherwise contact with patient material can arise, consequently (!) Personal protective equipment must be worn as a barrier against direct transmission.

  • Protective goggles (large) must be worn in every situation where splash injuries can occur. So also for example when changing a sieve in the extractor, rinsing out a dental impression and certainly also when processing dirty instruments in the sterilization area. The fogging of the glasses is sometimes uncomfortable, but should never be a reason to 'just' work without eye protection.
  • A mouth mask is worn in the same situation as the protective glasses, so always together with protective glasses. The nose openings must be completely covered by the mask. A stuffy feeling can be present for a while, but disappears when you persevere.



Protective goggles and mouth-nose mask always together


  • Use a clean mask for each patient and also when it is wet and therefore no longer provides protection. A mask worn under the chin (as can be seen regularly on advertising images ...) is an expression of misunderstanding about infection prevention. After all, the contaminated mask will contaminate the skin of the chin and there will form an indirect infection route when a subsequent mask makes contact with it. When re-gaining and correctly positioning the mask, the contaminated area with the hands / gloves is usually touched and the hands are the carriers of microorganisms from previous patients. These are in excellent condition, because of the heat and moisture that is present on the skin of the chin and on the mouth-nose mask. These vital micro-organisms are then introduced into the mouth of the next patient as the treatment progresses.
  • New examination gloves are worn on contact with patients or patient material. A powder-free variant is the standard, because the starch in the powdered gloves serves as a food source and as a transport medium for the micro-organisms that float in the aerosol. In the sterilization area, thick household gloves may offer better protection than the 'thick disposable' examination gloves mentioned in the guideline
  • The protective workwear is clearly described: light color, short sleeve, head covering should not come into contact with patient or patient material. Everything must be able to be washed at 60 ° C.



Head covering should not come into contact with the patient or patient material


  • Separate work shoes that are closed from above provide protection against injury in the event of a fall of a contaminated instrument. Moreover, the surface should preferably be able to be removed with moisture in order to remove visible contamination immediately. Sneakers such as work shoes are therefore a dubious application, the fabric is accessible to sharp instruments and in case of visible contamination, the fabric and the laces can not be cleaned immediately, or even not at all when the footwear is not washable


A Open shoes undesirable in connection with puncture injury. B Sneakers (washable), not laces


A Dirty dispotrays conveniently stacked. B Dirty drinking cups conveniently collected in special waste cooker


Approach to indirect contamination routes

These contamination routes are essentially addressed by reducing the number of living micro-organisms involved in transfer.


The measures each cover a separate area of attention for infection prevention:

  • The aerosol problem deals with the contagiousness of unit water and saliva.
  • Contamination via surfaces (lubrication contamination) is mainly related to good hand hygiene, supplemented with the use of protective materials and finally cleaning and disinfection.
  • Transfer via contaminated instruments (cross-contamination) is prevented by correct reconditioning of 'the stuff'.


Limiting the contagiousness of the aerosol

The aerosol is formed by minuscule droplets of water that are released when using spray cooling or flushing with the multi-function syringe. In addition, the entrained saliva is also a source for the contagiousness of the aerosol.


Measures to keep the aerosol as clean as possible should therefore focus on:

  • Suction in spray-forming instruments.


​​​​​​​The mist that is created must be captured with a mist extractor. So emphatically not with a saliva pistol.


For dental cleaning with ultrasound at locations where from an ergonomic perspective with indirect vision must be worked, with a solo working practitioner the need for (short-term) cooperation with a chair assistant. If adequate mist extraction can not be realized, alternative instruments should be used as an alternative.


  • Reduce number of microorganisms in saliva.

- A very effective measure is to have the patient flush for 30 seconds with a 0.2% chlorhexidine solution. Up to 94.1% reduction in the number of bacteria that can enter the aerosol when using ultrasonic equipment occurs.​​​​​​​


Heating the chlorhexidine to 47 ° C just before use and one minute rinse gives the most reduction. Afterwards, cooled chlorhexidine again contains toxic substances and leftovers must therefore be thrown away.


  • The disinfectant effect of rinsing with chlorhexidine persists for about one and a half hours after rinsing. This measure can also be used without too much difficulty as a routine measure for every treatment, even during an intake or PMO.
  • Working undercermerdam obviously also limits the number of micro-organisms that can end up in the aerosol. Especially the preparation under cofferdam gives profit in that area. Cofferdam is however only regularly applied when it is being filled.
  • To have unit water quality in order.​​​​​​​


Limiting transfer via surfaces

Contaminated surfaces must be cleaned and disinfected prior to subsequent use to prevent so-called contamination of lubrication contamination (spreading of microorganisms by touching contaminated surfaces). In the prevention of lubrication contamination, the simplicity in thinking and acting is aimed at:

  • Non-conditioning;
  • Pre-conditioning;
  • Recondition


​​​​​​​In this strict order they form the essence of practical action in infection prevention.


A logical consequence of the fact that micro-organisms do not actively move is that they are absent in places that have not been touched with patient material or contaminated hands / gloves. The first and best measure is to prevent lubrication contamination and this focuses on the non-contamination of surfaces and items, so there is no need to clean (non-conditioning). This not only saves time (!), It is obviously necessary for things that can never be cleaned, such as alginate powder.



Non-conditioning is applied with the no-touch method. To begin with, with disinfected hands, all instruments and materials are laid out in portions per patient. It is the intention during the treatment in principle nothing (need) to catch. Sometimes an exception has to be made for a fallen instrument that has to be replaced, or for incidentally some extra material that needs to be repackaged, because there was unforeseen shortage. Such 'sums' require that repacking be carried out with a careful hand hygiene regime.


In addition to the no-touch method, disposables and single-dose packages can be used for non-conditioning.


The use of paper towel and is indispensable in health care. Hand towels and tea towels are a breeding ground for micro-organisms after use and should be dried after each use and washed at 60 ° C. However, according to current insight, it is very desirable and fortunately also possible to pursue a 'towel-free' oral care practice.


Resistance to the use of disposables does not always seem to be based on correct grounds. Typical reconditioning requires labor time, cleaning agents, energy, clean water and thus costs. The environment may be better off with clean combustion or better still: increasingly degradable materials. A volume problem regarding the waste can usually be solved by convenient storage of used disposables or else a dirt press.


Single-use packaging GP points


Single-use (single-use) packaging is often slightly more expensive to purchase, but there are time savings and guaranteed hygiene compared to


Pen preconditioned, only one note sheet stuck on napkin


Products intended for single-use must absolutely not be used a second time! Only when black on white can be shown that a reconditioning process has been carried out, whereby the product could be safely reused, it is possible to use a tool or material for a second time. However, this burden of proof can not be provided in oral care practices and therefore one must strictly adhere to one-time use.


In the case of non-conditioning, bare (disinfected) hands are allowed. Clean gloves should not be used, because it is not obvious to determine whether they are really clean (or accidentally contaminated). On the other hand, bare hands will always be clean (enough), because there is no dental care worker who has handled contaminated materials or instruments with bare hands.


Bare hands are clean hands!



Pre-conditioning must be applied when the no-touch technique is not an option, for example with the curing light to be grasped, and when the material or the design does not allow reconditioning. Covering with foil or a protective cover (sleeve) is then required, because keeping clean is not allowed as cleaning!


A second category in which preconditioning is the case concerns surfaces where cleaning and disinfection are possible, but in practice it is not feasible to do this after each treatment. So, for example, coupling pieces for suction tubes and the sleeve of the multi-function syringe may be present in the thermodisinfector, but that will not always take place in practice after each patient treatment. In such cases, a sleeve is always required for these structures.


The (prevention) assistant will have to take measures for the pen used to record the DPSI scores during the treatment. Also, for example, the calculator / telephone used for calculating the plaque and bleeding scores should be protected with a sleeve or, if necessary, a sandwich bag against contamination, if not used after but during the treatment. A mixture of preconditioning and disposables occurs when (endo) treatments have to be made about the length of the pond. The pen must be preconditioned with a sleeve and in addition only a single post-it piece of paper is stuck to the patient napkin that serves as a work area. Using a whole notepad during treatment is very undesirable, because after contamination no form of reconditioning is possible. The notes are entered into the computer after the treatment, without the post-it sheet being moved. The note sheet is then discarded as a whole with the 'work field' napkin.


A Basic position instrument with sleeve. B Take out the multi-function syringe with a dirty hand. C Clean the instrument holder ('the pen'). D Grab the multi-function syringe at its 'tail'. E Stroop the sleeve. F Disconnect the disposable tip. G Put the multi-function syringe back in the clean room. H Deposit the disposable tip with sleeve on the tray


A voluntary category in which preconditioning can be applied are things that are easy and easy to clean and disinfect, but which provide an image of 'super hygiene' to the patient by covering with sleeves (eg sleeve around the unit handle) or the cleaning time shorten. The latter applies to a sleeve around the Proxeo, a polishing corner with disposable nozzles and without an internal water channel. The inside of the corner piece can not get soiled, because there are no water channels. This type of corner piece can normally be reconditioned, but when the outside is preconditioned with a sleeve, the corner piece remains clean on the outside and can be used for a whole working day without any cleaning operation.


A proper routine when removing the sleeves from the multi-function syringe and the like is necessary in order not to have to carry out cleaning work on the unit after all.


Squeeze bottle with alcohol to replenish alcohol​​​​​​​


Reconditioning (of surfaces)

As a rule, this concerns the treatment unit including the handles of the operation lamp and the holder of the extraction tubes. Possibly also the worksheet if that is unfortunately contaminated next to the defined work area. Reconditioning is achieved in two steps:

  1. Cleaning: Household cleaning / dilution of the dirt. ​​​​​​​In practice it appears that cleaning (of the treatment unit or worktop) is only carried out as a separate operation in case of visible contamination. This is best done with a wet tissue or a disposable tissue with a cleaning agent.
  2. Disinfection: Reduce the number of microorganisms to an acceptable level. Disinfection can be done with a 250 ppm (0.025%) chlorine solution, but the contact time is then five minutes and that makes it unsuitable for oral care practices. In addition, the surfaces disinfected with chlorine must be rinsed with plenty of water, which is also not practical. Moreover, a higher concentration of 1000 ppm (0.1%) is required for disinfection of blood contaminated surfaces.


If no visible dirt is present on the unit or any other surface, cleaning in oral care practice is usually skipped! It is sufficient to disinfect the contaminated surface. This procedure is generally accepted with the explicit condition that a wet cloth with disinfectant is used, so that the surface will remain wet as long as the prescribed exposure time for the disinfectant used. 


For the 80% alcohol used in oral care practices, the disinfected surface must remain wet for at least one full minute. Large (woven) cloths are better than the thin paper-like cloths on rolls. These carry little disinfectant and are quickly dry. As a result, all organic constituents of the contamination are spread over the surface instead of (partially removed and subsequently) disinfected. In principle, no spray-whipe spraying method is used anymore. A spray bottle may be available to moisten the cloth. It is better for that purpose to have a squeeze bottle with alcohol within reach.


Lockable container for disinfection by immersion


Limit transfer via instruments

The reconditioning of instruments to prevent cross-contamination is mentioned in the directive as one concept: RDS.


This includes successively:

  • Cleaning: Remove visible contamination and / or dilute the dirt;
  • Disinfection: Reduce the number of micro-organisms to an acceptable level;
  • Sterilization: Chance of finding live micro-organisms is less than 10-6.


These operations are performed in a separate room. In exceptional cases, editing is allowed in the treatment room, but then treatments and reconditioning of instruments must be done 'separately in time'. 


The guideline below describes the minimum processing that is necessary to be able to reuse instruments in the various risk categories.


It is shown here briefly:

  • Category A: critical use.


​​​​​​​CH-1: cleaning, thermal disinfection and packaged sterilization in a suitable steam steriliser (autoclave). This set of instruments is used for extensive surgical procedures.


CH-2: cleaning, thermal disinfection and minimal unpackaged sterilization. This set of instruments is used for smaller surgical procedures.

  • Category B: cleaning and thermal disinfection or unpackaged sterilization.


​​​​​​​This set of instruments comes into contact with mucous membrane, but is not used for surgical purposes.

  • Category C: cleaning and thermal disinfection.


​​​​​​​Instrumentarium that has been used outside the mouth, so has no contact with the mucous membrane.


Notes to this scheme:

  • Cleaning and disinfection are done mechanically using a thermodisinfector, because of efficiency, safety for employees and controllability of the process. With an ultrasonic cleaning device, it is possible to clean beforehand in case of hard-to-access structures such as (implant) drills.
  • In exceptional cases, instruments that can not enter the thermodisinfector and, moreover, (!) Have not been in contact with mucous membranes (ie category C instruments only) may undergo chemical disinfection in the form of immersion (!) In a bath with disinfectant. When using alcohol (70-80%) this should take at least five minutes. When using a different disinfectant, the instructions of the manufacturer must be strictly adhered to.
  • Endo files may only be used patient-specific due to insufficient cleanability.


Simplicity in clearing after a patient treatment:

  • Only the treatment unit has to be reconditioned, including surgical lamp and extraction unit. Everything else is disposable, or kept clean (no-touch technique) or it is for reconditioning in the direction of sterilization.
  • Changing the patients therefore takes as little time as possible and leaves maximum time for treatments in the treatment room.