Disinfection and Sterilization

Sterilization and disinfection are two of the most important aspects of any medical specialty. And they always have been, even though with the appearance of new infectious diseases such as AIDS, they have gained more attention from a population more aware in this respect.

Disinfect: means to clean, eliminating all potentially pathogenic micro-organisms (the majority of bacteria and viruses, such as AIDS or HEPATITIS B, amongst others). However, certain types of life forms such as spores can survive a disinfection procedure. Disinfection tends to be done with chemical products (bleach, iodine, alcohol...). Applying iodine to a wound or washing the floor with bleach are disinfection procedures.

Sterilise: means to eliminate any type of micro-organism that may have been deposited upon an object. Not even spores can survive a sterilisation process. Sterilisation is the procedure traditionally applied to operating theatres.

The sterilisation process is more costly, requires greater dedication and time than that of disinfection and accelerates the deterioration of the instruments, which therefore need to be replaced with far greater frequency. The regulations dictated by the CDC (centre for the control of diseases), the ADA (American Dental Association) and the FDI (International Dental Federation) stipulate a series of protocols to be followed. For example:

1. Disinfection of surfaces (tables, chairs, lamps) and of the hands with enzymatic soaps or chemical products such as alcohol or clorhexidine.
2. The use of masks, gloves, dams, and disposable sole-use materials (needles, cloths, napkins, glasses, saliva ejectors, aspirators, scalpels, etc)
3. All instruments in contact with oral mucous membranes are first disinfected and then sterilised in autoclave ovens at high temperature, humidity and pressure.

Currently there are modern pressure autoclaves that are smaller than the traditional ones, with micro-processors which control the process and ensure the sterilisation of all the material used within a very short time (4-7 min).

Therefore, the complete process which includes immersion of the materials in disinfectant solutions for 10 minutes, ultrasound bath, water washes, brushing and enzymatic soaps, drying, bagging and sterilising can all be done safely (by experienced personnel) in around 15 minutes.

The control of the sterilisation process is absolute and carried out with colorimetric tests and periodically with spore tests.

Although all these processes together bear a significant economic cost, the health guarantee that the rigorous application of all these techniques provides for the prevention of infections is an absolutely primordial concern in odontology.