Read the text carefully. Pay attention to words in the bold print
Proper sterilization of invasive instruments such as dental tools is extremely important to the practice of dentistry. Without proper sterilization of these tools, as well as dental equipment, various blood and saliva-borne pathogens can easily be transferred or shared among patients.

The commonly sterilized dental tools and equipment include mouth mirrors, detectors, excavators, pliers, elevators, burs, dental forceps, dental scalers and tips and turbine hand pieces. The medical technicians who are responsible for sterilizing dental tools and equipment usually record keeping of the tools, the chemicals used and the maintenance of sterilizing equipment. They monitor the shelf life of the chemicals to be cautious of their expiration date and efficacy.

One of the ways of decontamination of dental tools is saturated steam. Saturated steam under pressure is one of the most preferred methods of sterilizing and decontaminating dental tools. It is also the decontamination method most recommended by dental tool manufacturers, as it takes care of virtually all types of dental materials and instruments.

Another option is steam and chemical sterilizer. This method uses non-saturated steam at 132 degrees Celsius and a solution of chemical and water. The sterilizing cycle runs for about 20 to 30 minutes. One advantage of this method is that it does not corrode carbide steel and other corrosion-sensitive materials of dental instruments. Its only downside is that it produces a typically hazardous chemicalresidue, which explains the need to perform the process in a well-ventilated area.

Next choice can be iodophors which are iodine-based chemical solutions that are used for their powerful germicidal action. The tools are usually soaked for about 5 to 20 minutes in the solution to be effectively sterilized.

Another procedure which can be used here is chemical sterilization and disinfection. Compared to the method that uses steam, this mode of sterilization does not require putting the tools to high heat. Its disinfecting action relies on how long the tools will be soaked in the solution. In addition, this method also relies on adequate cleaning and brushing off of dental debris from the surface. Phenols are sometimes used to decontaminate dental tools. They work well with cleaners such as detergents; however, they may cause rusting of the tools.

Pre-vacuum Steam Autoclaving is another choice for disinfecting. This sterilizing machine is ideal for those tools that are sensitive to heat and moisture. The pre-vacuum sterilizers are fitted with a pump to create a vacuum in the chamber where the tools will be placed, allowing for steam penetration throughout the entire load.For tools that are heat- or moisture-sensitive, the chemical Ethylene Oxide (EO) is used.

GLOSSARY
advantage – korzyść, zaleta 
as well as – jak również 
be cautious – być ostrożnym 
be fitted – być wyposażonym 
borne – (tutaj) przenoszony 
bur – wiertło stomatologiczne 
carbide steel – stal karbidowa 
chamber – komora 
debris – szczątki, zanieczyszczenia 
downside – minus, wada 
efficacy – skuteczność 
entire – cały, kompletny 
excavator – ekskawator 
expiration date – data przydatności 
germicidal – bakteriobójczy 
hazardous – niebezpieczny 
heat – ciepło, wysoka temperatura 
invasive – inwazyjny 
load – ładunek 
maintenance – konserwacja, utrzymanie
mode – sposób 
moisture – wilgoć
option – opcja
pliers – szczypce, kleszcze
pressure – ciśnienie
proper – właściwy
pump – pompa
record – trzymać rejestr, notować, rejestrować
rely on – polegać na
residue – osad
run for – trwać
rusting – rdza, rdzewienie
saturated – nasycony
sensitive – wrażliwy na
share – dzielić
shelf life – okres trwałości/przydatności
soak – moczyć, namaczać
solution – roztwór
steam – para
vacuum – próżnia

Read this text and mark these sentences as True (T), False (F), No Information (NI)

1. Only invasive dental tools must undergo the process of sterilization.
2. Entire hand pieces are recommended for sterilization.
3. Dental technicians are responsible for sterilization. 
4. Medical technicians must follow recommendations of National Dental Association. 
5. Saturated steam is the most common form of sterilization.
6. The sterilization process with steam and chemical sterilizer must last at least 30 minutes. 
7. Iodophors form a residue on dental instruments during sterilization. 
8. Sterilization with iodophores is the cheapest choice.
9. Autoclaving should be used with instruments prone to rusting. 
10. It’s not necessary to remove any debris from the instruments before sterilization.

Match words from the GLOSSARY section with their definitions

1. ………………- is the length of time that foods, beverages, pharmaceutical drugs, chemicals, and many other items are given before they are considered unsuitable for sale, use, or consumption.
2. ………………- is a dental tool which is used to remove soft carious decay. 
3. ………………- material remaining after a distillation or an evaporation.
4. ………………- is space that is empty of matter.
5. ………………- care or upkeep, as of machinery or property. 
6. ………………- capacity for producing a desired result or effect; effectiveness. 
7. ………………- a rotary cutting tool usually of steel or other hard metal for removing carious material from teeth and preparing cavities for filling
8. ………………- the red or orange coating that forms on the surface of iron when exposed to air and moisture.

Complete the autoclave process description with words from the table

The first step in the autoclave process is 1)……………. all of the air in the autoclave 2)………………. The chamber is 3)……………. , and all of the air is removed through a 4)………………. pump. Once the air has been totally removed from the 5)…………….. , the tools or instruments are sterilized by 6)……………….. to heat. The sterilization cycle typically 7)…………… from 3 to 18 minutes, and the heat level is usually set between 121 and 134 8)……………. Celsius. The intense heat kills bacteria, viruses and other organisms. The autoclave works best when the items are placed inside in a way that allows the heat to 9)……………….. completely.

Put the following instructions in the proper order

Instructions on how to clean and sterilize dental instruments

_______ A. Dry the instruments with a disposable cloth. 
_______ B. Sterilize the instruments using heat, steam or chemical process. 
_______ C. Clean the dental instruments manually by soaking in warm water with non-foaming detergent. 
_______ D. Package the dried instruments into sterilization cassettes to prepare them for the sterilization process. 
_______ E. Scrub the debris and rinse carefully
_______ F. Remove the sterilized instruments from the unit.
_______ G. Load the packed instruments into the heat sterilization unit. 
_______ H. Store the instruments in their intact packaging. The packaging must be sealed and undamaged. If the packaging gets wet o damaged, sterilize the instrument again.

Lesson 24 answers