The ergonomics of hygiene and asepsis in periodontal and implant practice

The advancement of our practice, especially periodontal or implant surgery, leads us to be extremely vigilant in the management of our surgery, in our actions and, notably, in the rigorous respect for the rules of asepsis. Considering the high level of risk of contamination from these invasive procedures, a coherent and well-conducted aseptic regime implies thoughtfulness, rigor and attention to detail. These are some of the qualities required of a dental surgeon.

Our attitude, when facing patients, whatever their state of immunity, must prove to be as considerate as possible. All patients are sources of pathogenic agents. Theoretically, the risks of superinfection appear less important in the dental surgery than in the hospital environment. Nevertheless, the risk is real and must not be ignored. In fact, the expansion of dental techniques, notably the use of materials such as the hydroxyapatite, coral, tricalcium phosphate, bovine bone, membranes, etc., increases them.

It shows, therefore, that it is essential to put into place a system for the meticulous management of the surgery. Prevention of infection does not rest on impressive and erroneously reassuring measures. The fight against infection is a continuous action that is made in addition to a multitude of small well-taught and well-executed daily actions that have been well thought out within the organisation. The latter rests, therefore, not only on the organisation of the place where the procedure is undertaken but also, and especially, on the attitude of the surgical team, who must be motivated to aim for perfect control of asepsis (^{Missika and Drouhet, 2001}).

In this pre-eminent search for ideal conditions of hygiene and asepsis, in order to reduce to the maximum the risk of contamination, the question is raised of the necessity for a specifically allocated room for implant, periodontal or oral surgical interventions.

To be considered : a specifically allocated surgical room or not ?

Although, from the medico-legal point of view, the creation of a dedicated room for surgical interventions is not required, it is our considered opinion that in order to assure our patients of the requisite quality and safety for treatment, we must perform our surgical procedures in the best conditions.

The Swedish school of thought considers that very rigorous and very standardised conditions of asepsis are essential, which leads us to the necessity for an operative unit.

In the same way, Scharf and Bernard have undertaken some comparative studies. Similar interventions were undertaken under strict aseptic conditions or under so-called « hygienic » conditions.

The Scharf and Bernard studies

^{Scharf et al. (1992)} placed 273 Brånemark implants in 60 patients in conditions of strict asepsis, and 113 implants in 30 patients in a periodontal clinic in so-called « hygienic » conditions.

This involved :

- sterile implants and instruments ;

- sterile irrigation solutions ;

- sterile gloves ;

- the wearing of a mask ;

- no cap ;

- no sterile gown ;

- no overshoes ;

- no sterile towels on the patient.

The survey lasted 8 years from 1983 to 1991. Similar results were obtained for the two study groups :

- 98,9 % success in sterile conditions ;

- 98,2 % success in « hygienic » conditions.

^{Bernard et al. (2000a)} studied the success rates of ITI non-submerged osseointegrated implants placed in either sterile or aseptic conditions. In both protocols, the rooms were identical. Group 2 (192 patients, 427 implants) differed from group 1 (201 patients, 423 implants) by the fact that the surgeon was not wearing a sterile gown. Bernard et al. attempt to demonstrate that by a very rigorous and very strict attention to the surgeon's actions, the results are identical.

On the day of loading and one year later, the percentage success rates are, for group 1, 99,1 % and for group 2, 99,8 %. The results are, therefore, essentially similar. To confirm the findings of this one-year study, it is interesting to pursue the observations over a longer period, up to five years, by the same authors (^{Bernard et al., 2000b}) : 1 553 implants were placed during this period, in accordance with a single protocol (aseptic conditions). One notes a percentage of failures up to five years of 0,77 % and the results essentially comparable.

The analysis of these two studies would tend to suggest that we opt for surgery done under aseptic conditions. Few studies have been reported in this area, nevertheless, the Swiss team specifies that most implant surgeries work in conditions that are said to be « aseptic ».

Discussion

Bacterial contamination exists, in both a dental surgery or in a room specifically for surgical use (^{fig. 1}). According to ^{Zeitoun (1992)}, air, water, surfaces, the patients, etc., are all sources of pathogens. Physical actions, movements, verbal exchanges… can also cause microbial dissemination.

Airborne bacterial contamination can be reduced by applying simple rules, but they have to be applied rigorously and efficiently by a trained and competent team consisting of at least three or four persons. It can be dealt with by local cleaning and disinfection, by improving air quality and ventilation, and by an appropriate attitude amongst the staff. A rigorous regime is, therefore, essential. « The training and the motivation of the surgical team will always be the determining factor for effective prevention » (^{Bert and Missika, 1995}). It appears that the ideal number of personnel during periodontal or implant surgery is three, one of whom has responsibility for the instruments. However, for economic reasons, this ideal is not always attainable. Periodontal or implant surgery with only two people requires the most meticulous organisation.

Therefore, it is necessary to keep in mind that the preparation, the decontamination of the surgical room and the actions of the operators are factors that are essential to obtain a positive outcome, and are more important than the place in which the surgery is undertaken. In this respect, it proves to be important to follow some basic rules of asepsis.

Basic rules of asepsis

It is advisable that sterilised equipment and materials, as well as disposables should be double-wrapped and that the packs are opened close to the operative area. The instruments can then be slid onto the operating table.

With regard to the preparation of surgical room :

- if it is a general dental surgery converted into a surgical room, meticulous preparation is necessary. That means covering all work surfaces with sterile sheets, after clearing them of all unnecessary objects. It is also advisable to reserve an adequate time slot in order to not to be disturbed by other work ;

- if a room specifically allocated for surgical interventions is used, the preparation of the room is simplified, especially if the existence of an ante-room allows the patient as well as the practitioner to get ready for the surgery (overshoes, cap, gown or sterile tabard…).

In the operative zone, clothing must be sterile, although this does not seem to be obligatory if one refers to the survey by ^{Bernard et al. (2000a)}. However, it does reduce the risk from an error of asepsis.

A mask must be worn, and to be effective, should be put on properly. Indeed, it has been demonstrated that 13 % of people carry staphylococci in their respiratory tracts, which indicates the fundamental importance of this form of protection. According to ^{Zeitoun (1992)}, it remains effective for 3 hours.

It is necessary to wash the hands according to surgical principles (^{Girard et al., 1996} ; ^{Mathieu, 1993}), and to wear sterile gloves. Care must be taken to keep the hands in front of oneself and above the sterile area. Gloves remain sterile for 45 to 60 minutes, therefore it is necessary to change them every hour.

It is necessary to reduce the amount of movement in the room as much as possible, in order to avoid the proliferation of particles producing bacterial colonies. For the same reason, it is recommended not to talk more than is necessary.

The patient will be covered with sterile towels over the body and round the head.

Also, note that the site of surgical intervention can be contaminated by the environment around the mouth, making it necessary to meticulously disinfect the surrounding skin, from the area of surgery outwards. Saliva can be also vector for bacteria, hence the need for very effective aspiration.

The ergonomics of periodontal and implant surgical procedures

According to English concept of risk, oral surgery is considered to be « high risk », requiring the use of disposable materials, or otherwise high-level decontamination. Nevertheless, it can be classified in three levels :

- simple surgical procedures, such as straightforward extraction teeth ;

- more complex surgical procedures such as flap surgery, including periodontal surgery (e.g. open flap curettage, access flaps, apically repositioned flaps) ;

- more complex, specific surgical procedures such as muco-gingival periodontal surgery (e.g. submerged connective tissue grafts, guided tissue regeneration, guided bone regeneration) and implant surgery (e.g. placement of implants, bone grafts, sinus lift graft procedures).

Whether the surgical intervention is periodontal or for implants, the ergonomics and actions are governed by the same strict and effective rules.

Ergonomics and physical actions

In order to work in the best conditions of hygiene and asepsis, the ergonomics of the procedure should be meticulous and flawless. This demands a well-thought-out and functional organisation of the tray system. The instruments will have been carefully placed in the order decided by the practitioner, according to his routine (^{fig. 2}). His actions will, therefore, be simplified, logical and devoid of superfluous and ineffective movements.

In order to assure to the best results from periodontal or implant surgical procedures, the experienced practitioner must remain constantly alert and bear in mind the operative protocol in order to minimise ineffectual actions. Equally, he must manage and organise his team so that each member has a predefined role. He will coordinate the progress of the intervention in a precise, confident way, yet calmly and without fuss. In order to decrease the risks of bacterial contamination, it appears to be important to keep the time taken for the intervention short. Therefore, aiming for perfection in terms of one's actions and organisation will help lead to the best possible surgical technique, in optimal conditions of hygiene and asepsis.

Organisation surgical intervention

The organisation of surgical intervention can be divided into four parts :

- the preparation of the room intended for surgery ;

- the preparation of the patient ;

- the preparation of the surgical team ;

- the organisation of the instrument tray.

According to the complexity of the surgery that is to be performed, the preparations of these different components will be more or less painstaking.

Periodontal and implant surgical procedures are considered to be « complex », requiring a specific level of expertise and organised with the same meticulous attention to detail.

Preparation of the surgical room

The room is prepared in accordance with the requirements of intermediate level decontamination (zone 2, according to the description of ^{Chopin, 1994}). In the actual area of the intervention (incision, zone 0 ; instrument tray, zone 1), the instrumentation is sterile or, failing that, must undergo a high-level disinfection.

The scrubbed assistant, wearing mask, gown and sterile gloves, will prepare a trolley, covered with a sterile towel. This surface will receive the sterile instruments essential for the intervention (^{fig. 3}) :

- surgical box ;

- instrument kit specific to the intervention (periodontal or implant) ;

- sterile, disposable aspiration tip ;

- sterile cupules ;

- sterile towel for patient's head area.

These will all be covered with a sterile towel that will serve to cover the patient's body.

Another trolley will also be prepared in this zone. It will include the sterile instrument packs that can be opened as necessary during intervention. It will also have packs of other materials and implants that can be opened immediately before they are used.

For implant surgery, a third trolley will be necessary. This will include the surgical motor that will have been decontaminated and placed on the sterile surface, ready to receive the micromotor and the sterile lead (^{fig. 4} and ⁵). Note that for these two types of surgery, sterile sheaths will be placed on the aspiration tube and on the handle of the operating light.

Preparation of the patient

For rapid decontamination of the oral cavity, the patient is asked to rinse with a chlorhexidine mouth-wash for a period of three minutes.

The patient dons overshoes before going in the surgery and is then invited to sit in the dental chair. The scrubbed assistant, covers the patient's body and around the head with sterile towels.

Preparation of the practitioner and the assistant

Overshoes, hat and mask will be put on. Then, the hands are scrubbed methodically and meticulously three times. The second assistant presents the sterile gown that the practitioner slips on and the assistant ties. Finally, the sterile gloves are put on.

Organisation of the surgical tray

This requires optimal conditions. The trolleys in zone 1 are arranged in the most ergonomic way possible in order to facilitate surgery and to reduce the amount of ineffective movements. Meticulous attention to detail is required.

Conclusion

The approach of the surgical team, thanks to the painstaking temperament of the surgeon, must allow the periodontal or implant surgery to be carried out in a consistent manner. This is essential in order to ensure mastery of the aseptic chain and the quality and safety of these therapeutic procedures. Only a thoughtful approach by the practitioner will promote the necessary attention to detail that is needed to achieve this line of action, the object of which is to manage the ergonomics with a view to optimal standards of hygiene and asepsis.

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BIBLIOGRAPHIE

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