Department of Prosthodontics/Dental Material

FIRE FIGHTING AND USE OF FIRE EXTINGUISHERS

Safe Operating Procedure

FIRE SAFETY – GENERAL PREVENTION AND EXTINGUISHERS

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This SOP provides general information on fire prevention, as well as detailed information regarding fire extinguisher classification, type, size, location, and use. Other EHS SOPs provide information regarding fire safety related to specific materials, such as flammable liquids, compressed gases, pyrophoric chemicals, etc.

Fire Prevention

• Keep hallways, corridors, and exit areas clear of items that impede egress in an emergency (i.e., chairs, tables, boxes, equipment, etc).
• Properly store combustible items. Do not accumulate unnecessary cardboard boxes, chemicals, and paper products.

• When stacking or storing items on shelves, the top of the items must be a minimum of 18” below sprinkler head deflectors.
• Avoid storage of flammable liquids outside of a flammable storage cabinet. See EHS SOP, Storage and Use of Flammable and Combustible Liquids for more information.

• Properly store compressed gas cylinders.
• Segregate chemicals by hazard class. See EHS SOP, General Guidance for Chemical Storage for more information.
• Purchase equipment that is approved by a testing organization,
• Keep electrical equipment, cords, and plugs in good condition. Arrange for an authorized factory representative or electrician to replace electrical cords or plugs that are in poor condition (i.e., frayed, cracked insulation, loose prongs, etc.).
• Do not overload electrical outlets.
• Report loose electrical wall receptacles, missing outlet faceplates, and exposed wires to the Building Maintenance Reporter (BMR)/ Electricity department of the university.
• Disconnect electrical equipment that could overheat when unattended.
• Keep fire extinguishers charged, stored in their designated location, and ensure annual inspection.
• When using a space heater, allow a minimum of three (3) feet between the heater and combustible materials.
• Turn off the electrical and heat-producing appliances at the end of the day.

• Refrain from open flames (i.e. candles, Sterno burner, incense burner, etc.) unless they are an

integral part of the work activity (i.e., Bunsen burners in laboratories, torches in welding shops,

etc.). Do not leave open flames unattended.

• Do not store or use ordinary combustibles (i.e., papers, napkins, cloths, etc.) or flammable/

combustible solvents (e.g., aerosols, paints, etc.) in the vicinity of open flames or hot surfaces.

• Know how to safely exit the work area if a fire should occur. Have at least two (2) exit routes in

mind and walk through them to assure your safe response. Always observe a fire alarm.

Convene in the predetermined safe gathering location.

• Use appropriately designed tools for handling hot equipment or surfaces (don’t improvise with

dish towels, rags, etc.).

CALL EMERGENCY NUMBER 100/101/112

Classes of Fires

The Fire Protection Association categorizes fires by class. Newer fire extinguishers use a picture/labelling system to designate which types of fires they are to be used on. Older fire extinguishers are labelled with coloured geometrical shapes with letter designations. Icons for both are shown below. Many extinguishers are designed for more than one type of fire and will therefore be labelled with more than one designator.

Class A – Trash, Wood, Paper
Class A fires involve ordinary combustible materials--paper, wood, fabrics, rubber, and many plastics. Quenching by water or insulating by a multipurpose (ABC) dry chemical agent is effective.

Class B - Liquids, Grease
Class B fires occur inflammable liquids--gasoline, oils, greases, tars, paints, lacquers, and flammable gases. Dry chemicals and carbon dioxide agents extinguish these fires.

Class C - Electrical Equipment
Class C fires take place in live electrical equipment--motors, generators, switches, and appliances. Nonconducting extinguishing agents such as dry chemicals or carbon dioxide are required to extinguish them. Fire extinguishers for the protection of delicate electronic equipment shall be selected from types specifically listed and labelled for Class C.

Class D - Combustible Metals
Class D fires occur in combustible metals such as magnesium, titanium, zirconium, sodium, lithium, and potassium. Sodium carbonate, graphite, bicarbonate, sodium chloride, and salt-based chemicals extinguish these fires. There is no picture designator for Class D extinguishers.

Class K - Cooking Oil Fires.
Class K fires occur in cooking appliances that use combustible cooking media (vegetable or animal oils and fats).

Types of Fire Extinguishers

• Multipurpose Dry Chemical for Class A, B, and C Fires. The monoammonium phosphate agent is inexpensive and electrically nonconductive but leaves a powdery residue that can damage equipment. This type of extinguishing agent is not good for hidden fires.
• Water for Class A Fires. This type of extinguishing agent is not appropriate for areas with Class C hazard potential because water will conduct electricity.

• CO2 for Class B and C Fires. Carbon dioxide is a colorless, odorless gas that leaves no messy residue to damage equipment. This type of extinguishing agent is good for reaching hidden fires, however, the heavy vapor settles out, limiting the total discharge range to approximately 8 ft. (2.4 m). Carbon dioxide may also cause thermal (cold) and static (shock) damage.

• Dry Chemical for Class B and C Fires. The potassium bicarbonate and sodium bicarbonate extinguishing agents are extremely effective against Class B fires and are electrically nonconductive. They are considered non-toxic and cleanup may be accomplished with a vacuum cleaner or broom and dustpan.

• Dry Chemical for Class D Fires. Extinguishing agents include sodium carbonate, salt, graphite, bicarbonate- and sodium chloride-based chemicals. These agents are not equally effective on all combustible metal fires. Be sure the extinguishing agent chosen will be effective on the combustible metal present, as using the wrong extinguishing agent can increase or spread the fire.

• Wet Chemical for Class K Fires. Potassium acetate is the agent specifically listed and labeled for use on Class K fires. Portable Class K fire extinguishers are intended to supplement automatic fire extinguishing systems.

Ratings of Fire Extinguishers

The fire rating of an extinguisher provides a guide to its extinguishing ability.,

Class A and Class B fire extinguishers carry a classification on their nameplates that consists of a numeral followed by a letter. The numeral indicates the approximate relative fire extinguishing capacity of the extinguisher on the class of fire, which is identified by a letter. For example, a 4-A extinguisher has approximately twice the extinguishing capacity as 2-A extinguisher.

Class C and D extinguishers carry only the symbol and have no numerical rating. Fire extinguishers and extinguishing agents for use with Class D hazards shall be of types approved for use on the specific combustible metal hazard. This should be detailed on the fire extinguisher nameplate.

Location of Fire Extinguishers

Fire extinguishers are required to be conspicuously located where they will be readily accessible and immediately available in the event of fire. Preferably, they shall be located along normal paths of travel, including exits from areas. Extinguisher placement must fulfill both distribution and travel distance requirements. Fire extinguishers must not be obstructed or obscured from view. In large rooms, and in certain locations where visual obstructions cannot be completely avoided, means shall be provided to indicate the extinguisher location.

Scattered or widely separated hazards must be individually protected. A fire extinguisher in the proximity of a hazard shall be carefully located to be accessible in the presence of a fire without undue danger to the operator. Portable fire extinguishers must be installed securely on the hanger, or in the bracket supplied by the extinguisher manufacturer, or in a listed bracket approved for such purpose, or placed in cabinets or wall recesses.

Number of Fire Extinguishers Needed

The number of extinguishers needed is determined by the authority having jurisdiction (usually the local or state fire marshal). This determination is based on the rapidity with which a fire may spread, the intensity of the heat that may develop, the travel distance (actual walking distance) from any point to the nearest fire extinguisher, and the accessibility of the fire.

Use of Extinguishers

Any person who is designated or intends to use a fire extinguisher must be trained in its use.

SOPs for TEACHING

Aims: To ensure that the learning environment of its dental education program is conducive to the ongoing development of explicit and appropriate professional behaviours in its dental students and faculty.

§ Professionals demonstrate adherence to the highest standards of personal, professional, and academic honesty and integrity.

§ To periodically evaluate the learning environment to: a) identify positive and negative influences on the maintenance of professional standards b) implement appropriate strategies to enhance positive and mitigate negative influences c) identify and promptly correct violations of professional standards

§ To not allow our conduct to negatively impact others' learning or clinical activities

§ To not discriminate against students based on such grounds as age, race, colour, ancestry, place of origin, ethnicity, political beliefs, religion, marital status, family status, physical or mental disability, sex, sexual orientation or gender identity

§ To communicate respectfully with others both verbally and in writing

§ To respect the privacy and confidentiality of those to whom we owe that duty

Undergraduate teaching:

1. Lectures: it’s the main mode is theoretical teaching for undergraduate students. The course work is divided among all the faculty members at the beginning of the session according to their respective thrust areas. The teaching schedule for the entire session is passed by the members of the BOS of the department.

2. Clinical demonstrations: undergraduate students must be exposed to different clinical procedures through appropriate demonstrations by faculty members.

3. Problem based learning: it mainly includes clinical teaching. Every faculty member on his/her OPD day must take at least 45 minutes of clinical teaching mainly based on a particular clinical problem and then outline the aetiology, pathogenesis and management of that particular problem.

Post-graduate teaching:

1. Seminars: one seminar presentation is to be done by one post-graduate student every week on his/her respective turn. The topics for the seminars are decided by the BOS every year at the beginning of the session for the entire session.

2. Journal Clubs: one article from reputed journals is discussed once a week

3. Group discussion: conducted once a week in which all the postgraduate students and faculty members participate

4. Case Discussions: postgraduate students present their clinical casework in front of the faculty members for discussion and critical appraisal.

5. Pre-clinical & clinical demonstrations: postgraduate students are trained on models for mastering different incision and suturing techniques. The consultants demonstrate all the surgical techniques on selected cases to the postgraduate students.

SOPs for CLINIC WORK DURING COVID

• Observe social distancing measures at all times (minimum 2 meters)

• Clear safety standards for PPE & IPC

• Appropriate sequencing and scheduling, management, discharge and referral of patients,

• Only non AGP care to be given with appropriate PPE (eye protection, surgical masks, disposable apron & gloves)

• Intervention to minimum, to reduce exposure risk

• Using one-way entry/exit for patient flow

• Cleaning and decontamination of area before and after every patient daily

PPE: personal protective equipment

IPC: infection prevention & control

AGP: aerosol generating procedures

SOPs for OFFICE

§ Official Working Hours 8:00 AM – 4:00 PM

§ Maintaining records of all the documents received and dispatched from the department

§ To put up all the receiveddocuments before the chairman

§ To carry out the duty in accordance with the comments of the chairman.

§ To make arrangements for the exams conducted in the department

§ Filing documents in their respective files (Office file/Personal file/Circular file/ Notice Board file/ PG file/NAAC/IQAC/File for Minutes of BOS).

§ To maintain all the details of purchases and expenditure made by the department.

§ The following record registers are maintained by the office

Official Work Records

1. Register for received documents

2. Register for dispatch documents

3. Register for departmental meetings

4. Register for BOS

5. Register of leave record of teaching & non-teaching

6. Register for attendance of teaching, non-teaching, post graduates, undergraduates, interns & hygienists

7. Register for duty of teaching & non-teaching during holidays

Clinical Work Records

1. Register for general patient registration in UG CLINIC

2. Register for student patient registration in UG CLINIC

3. Register for patient record in PG CLINIC

4. Register for daily work done record of Consultants, Postgraduates, Undergraduates, Interns, Hygienists

5. Register for equipment allocation to consultants & postgraduates

Financial Records

1. Register for purchase committee meetings

2. Register for immovable assets

3. Register for record of all the instruments in the department

4. Register for record of repair of various items

5. Register for day-to-day expenses

6. Register for consumables items

7. Register for Bank related work TA, DA.

8. Indent book register

STANDARD OPERATIVE PROCEDURE FOR DENTAL CHAIR

 Before seating the patient on a dental chair turn on the switch manually and check for all the functions. Open the valve for compressor and water lines.

 Before seating the patient, the equipment and surfaces subject to contamination should be cleaned and disinfected

 Adjust the position and height of the dental chair to make the patient comfortable and keep in mind the ergonomics of the operator.

 At the beginning of each clinical session, flush water through water lines for 2-3 minutes.

 The surfaces of the dental unit are covered with disposable food-grade cling foil plastic. The use of disposable glass and suction tips for each patient is done

 The dental operator, assistant, and all personnel within two meters of patient care should wear impervious surgical gowns/scrubs with a well-fitting N-95 mask.

 Sensor taps or taps with elbow handles should be preferred.

 Avoid the use of towels; Paper towels are preferred

 Pre-procedural mouthwash (povidone-iodine, chlorhexidine, chlorine dioxide) for at least 15 seconds may be helpful in a transient reduction of viral load.

 Infection control guidelines with special considerations for aerosol or splatter generating procedures should be followed:

 High vacuum suction with a minimum suction capacity of 6.6 litres per minute.

 Use face shield.

 Use a rubber dam wherever possible.

 Keep adequate fallow time in between two procedures.

 Clean and disinfect equipment and operatory surfaces with 1% sodium hypochlorite or 70% alcohol for appropriate contact times.

 Remove soiled gown as soon as possible. The procedures and prescriptions are recorded only after doffing the PPE.

 Patient to perform hand hygiene and to be provided with review /follow-up instructions.

 Remove the water bottle and clean it every day after work and flush out disinfectant through the water lines.

 Turn off the valves for compressor and water lines and switch off the dental chair unit after work.

STANDARD OPERATIVE PROTOCOL FOR PATIENT WAITING LIST

Patient reporting to the departmental OPD

After diagnosis is made depending on the severity of the case, the patient is enrolled on the waiting list register available on the O.P.D. 3 counter.

Patient

Two different waiting list register is maintained.

One for general patient and one for university student and employee.

Patient

While providing waiting number, patients detail is noted in the register. That includes, name, age, sex, diagnosis, address and mobile number.

Once the waiting tenure is over, the patient is informed through calling and by text messages.

When the patient report to the O.P.D, is than allotted to the junior residents, senior resident and faculties.

SURFACE PROTECTION PROCEDURES

 Surfaces that are likely to be contaminated by the dental surgeon handling it or by the spill or spatter of oral contaminants should be disinfected .Surfaces touched by the dental surgeon are called TOUCH SURFACES.

 E.g. unit handles, various controls, light cure unit, micromotor,ultrasonic handpiece, 3 way syringe etc. these instruments need to be treated with disinfectants or coveredwith a protective barrier.

 The surfaces which are contaminated by contact with soiled instruments are called TRANSFER SURFACES.

 E.g.instrument trays, tube and hand piece holders.

 SPLITTER SURFACEis any surface which is not a touch or transfer or instrument surface and is within few feet of the oral cavity e.g. the dental chair surface. These surfaces are not cross contamination surfaces.

 Prevention of contact by touching and elimination of spill and spatter is ideal for preventing infection from surfaces. Since it is not possible, two main methods of protection of surfaces are used which are disinfection and barriers

 Disinfection involves cleaning of surfaces after every patient and application of disinfectant chemical material. These chemicals include—alcohol, iodophore, synthetic phenols, gluteraldehyde, chlorine etc.

 Dental patient chair: All chair functions should be controlled from a foot switch to avoid possible contamination by use of hand operate switches. Greatest potential for cross contamination is from chair mounted controls. Covering switches with clear plastics, which is replaced between patient sessions, will allow visualization and use without contamination of switches.

 Task seat or chair: Dentist should not touch seat covering with contaminated hands. Cleaning and disinfecting of porous seat covering may be accomplished with soap and water.

 Spittoons: Spittoons should be flushed with water, scrubbed and disinfected. Assembly around spittoons can be protected by barriers and removed when contaminated.

 Cabinetry: The amount of cabinetry should be minimized and they should be made from material that will with stand repeat cleaning and disinfection.

PROCEDURE FOR CLEANING OF DENTAL UNIT WATERLINE

 All water lines should be flushed for 3-5 minutes if the system has been idle for several hours.

 After each patient running high speed hand pieces for a minimum of 20-30 seconds to discharge water and air should be done to flush out patient material that have entered during use.

 Routine disinfection of water lines is possible by using a disinfection solution in water lines while unit is idle.

 Anti-retraction valves to prevent backflow of patient material into water line should be regularly tested for proper functioning

 Suck about 1 litre of 1% sodium hypochlorite through thesuction line at the end of the day, leave it for overnight. Next day before starting the work rinse with water and use.

SURFACE DISINFECTION

 Materials like sodium hypochlorite 5.25% (1:10 dilution), iodophors like Biocide & combination synthetics (Phenolics, Multicide & Omni II Vitaphine) have the disadvantage of leaving surfaces wet for 10 minutes, which is inconvenient in a busy dental practice.

 Glutaraldehyde products that are intended to be used as surface disinfectants contain only 0.25% (w/v)glutaraldehyde. However, they should be used with care, as repeated contact may damage the skin.

 Surfasept S.A is a commercially available disinfection solution which is aldehyde free, contains Isopropyl alcohol, chlorhexidine digluconate and flavoured excipient. It must be sprayed onto the area which must be completely and uniformly moistened then wiped.[9]

 Surface disinfection can be done by scrubbing the surface with the iodophor-soaked gauze pads and allowed to dry. Then 70% isopropyl alcohol should be used to remove the residue.

INSTRUMENT DISINFECTION

Least critical instruments such as Ligature tier and distal-end cutter, tying pliers, arch forming pliers, torquing keys, boons gauge, elastomeric rings etc. should be disinfected

Quaternary ammonium compounds are cationic surface acting agents. Commonly used ones are Cetrimide and Benzylkonium chloride. Disadvantages with these compounds are that they get inactivated by soap, reduced activity in presence of metal ions common in natural water, reduced effectiveness in presence of organic matter, lack of activity against tuberculous bacteria and are not sporicidal

8% solution of formaldehyde in alcohol and 2% solution of activated glutaraldehyde were considered to be two disinfectant of choice. But apart from toxicity issues, aldehyde based solution cause corrosion and rusting of stainless steel instruments which comprise majority of dental and orthodontic instruments.

Hence, an alternative solution is 5% Bibforte solution (ALPRO MEDICAL GMBH, Germany) which is aldehyde free, non- toxic and non-corrosive disinfectant. 100g BIB forte contains2.2 g dodecyldipropylenetriamine, 1.7 g trialkylethoxyammoniumpropionate, tensides and auxillaries. It is bactericidal (incl. TBC, MRSA), yeasticidal and virus inactivating. 5% solution is made by adding 50 ml of Bibforte solution to 950 ml of water and instruments are immersed in 5% solution for 30 minutes for effective disinfection. In emergency situation, 10%Bibforte solution with 5 minutes immersion of instruments can used for early and effective disinfection (as recommended by manufacurer) [10].

STERILIZATION

Sterilization can be accomplished in one of several ways. Some of the most common ways that are followed in orthodontic practice include steam autoclave sterilization, dry heat sterilization, chemical vapour sterilization and ethylene oxide sterilization

Instrument Processing

The overall process consists of

 Holding ( presoaking )

 Precleaning

 Corrosion control, drying, lubrication

 Packaging

 Sterilization

 Sterilization monitoring

 Handling processed instruments

Presoaking: Placing instruments in presoak solution until time is available for full cleaning prevents drying, begins to dissolve organic debris and in some instances begin microbial kill. Presoak solution consists of detergents, enzymes, or detergents containing disinfectants. Used solution should be discarded atleast once a day.

Cleaning: Blood, saliva and materials on instrument can insulate underlying microorganisms from sterilizing agents. Cleaning reduces this bioburden. Cleaning solutions with antimicrobial activity can eliminate build up of contaminants as the cleaning solution is being repeatedly used.

Hand cleaning: is an effective method if performed properly. Heavy utility gloves and protective eyewear should be worn during hand cleansing of instruments. Instruments should beimmersed in the detergent solution and then scrubbed with soft brush.

Mechanical/Ultrasonic cleaning:

Coupling of powerful ultrasonic vibrations with cold disinfection increases the effectiveness of the process. In a densely packed pile of instruments, there is only a thin layer of disinfectant around each instrument; vibration assures penetration of a properly concentrated solution into every area of every instrument [13]. Cleaning solution specifically recommended for use in ultrasonic cleanser should be used in proper dilution. The instruments are kept in the ultrasonic cleanser basket and submerged in the cleaning solution.

Ultrasonic Cleaner: The cleaner should be covered and operated for 6-10 minutes or until no visible debris remains. If instrument cassettes are used cleaning time is increased to 15 minutes. After cleaning instruments are thoroughly rinsed. Cleaned instruments must be considered contaminated and handled with gloved hands.

CORROSION CONTROL AND LUBRICATION

Corrosion

It is an electrolytic process in which the contact of two dissimilar metals or dissimilar areas within a single metal sets up a potential difference resulting in an electron flow. The electron flow leaves behind reactive ions that readily combine with atmospheric oxygen to form oxides (rust). Conditions such as extreme temperatures, physical abrasion, galvanism, or reactive extraneous ions that disrupt the chromium oxide layer will render the steel vulnerable to corrosion. Instruments made of carbon or 400 series steel are more susceptible than those of 300 series steel. Recent studies showed no significant difference in mean wear whether sterilized with steam autoclave or dry heat.

To reduce corrosion

•Clean and remove debris from the instruments and rinse with distilled water.

•Avoid tap water which contains dissolved alkali and metallic ions.

•Water must be deionized and of good quality.

•Keep the pH of steam above 6.4; otherwise pitting will occur.

•Chrome plated instruments and stainless steel instruments should be sterilized separately because the electrolyte action can carry carbon particles from the exposed metal of a chromium plated instrument and get deposited on stainless steel.

•It is better to keep the instruments in wrapping. Detergents with chloride bases should be avoided because chloride residue unites with steam to form HCl.

•Detergents with pH of more than 8.5 may disrupt chromium oxide layer.

Packaging: Cleaned instruments should be packed prior to sterilization to protect them from recontamination after sterilization. The instruments should be packed in an appropriate wrapping material before sterilization. A wrapping material designed for a particular type of sterilizer should be used with the sterilizer. E.g. A single layer cloth wrap for steam sterilization, self sealingpolyfilm paper pouches for chemical vapour sterilization, paper wrap for dry heat sterilization. Wrapping material should be self sealing or heat sealed or double folded and sealed with appropriate tape.

TYPES OF STERILIZATION

HOT AIR OVEN: Dry heat denatures protein of microorganisms rendering it nonviable. It operates at a temperature of 160oC for 1-2 hours. Smaller dental units are convection ones without forced air circulation. Larger units have large capacities and are either convection or forced air circulation unit. Sterilization time begins only after the proper temperature of 160°C is reached and then this temperature must be maintained.Common misuse is opening the door to keep forgotten things without starting the cycle again.

RAPID HEAT STERILIZER:Uses controlled internal air flow system at 375°F. Sterilization claims of 6 minutes are made with unwrapped instruments and 12 minutes for wrapped instruments.

AUTOCLAVE: Moist heat denatures and coagulates protein of microorganisms. The sterilization is due to latent heat of vaporization present in moist heat. When steam condenses on contact with cooler surfaces, it becomes water and gives latent heat to that surface. This principle is used in autoclave.Temperature required is 121°C for 20 minutes at 15 pounds pressure. For practical considerations high pressure vacuum models are operated at a temperature of136°C for 5 minutes at 30 pounds pressure.

Generally all pliers stood well to combination of routine clinical use and steam autoclaving. However, the SS pliers appeared to perform the best.

UNSATURATED CHEMICAL VAPOUR STERILIZATION:

Uses specialsolution containing 0.23%formaldehyde (active ingredient) and 72.38% ethanol plus acetone, ketone, water and other alcohols. It’s a suitable method for orthodontic instruments.

Operates at 270oF(132o C) with 25 pounds pressure for 20 minutes.

ETHYLENE OXIDE STERILIZATION:

Ethylene oxide at normal temperature is a gas with very high penetrating ability. It acts by alkylating the amino, carboxyl, sulphhydril groups in protein molecules. It reacts with RNA and DNA. Used to sterilize heat sensitive instruments.

SPECIAL CONSIDERATIONS FOR ORTHODONTIC ARMAMENTARIUM

ORTHODONTIC PLIERS:

High quality stainless steel pliers can be sterilized by steam, dry heat, chemical vapour and ethylene oxide gas .For low quality pliers steam autoclave is not preferred for it may damage the material. For pliers with plastic parts ethylene oxide sterilization is the only effective method. Effects of Three Types of Sterilization on Orthodontic Pliers were studiedby Mazzochi et al. [15]. The study showed that clinical and metallurgic modifications of common orthodontic pliers after 500 cycles of sterilization in autoclave, chemiclave, or dry-heat units are negligible. Vendrell and Hayden compared the wear of orthodontic ligature-cutting pliers after multiple cycles of cutting stainless steel ligature wire and sterilizing with dry heat or steam autoclave. Fifty ligature-cutting pliers with stainless steel inserts were randomly divided into 2 equal groups to be sterilized in either dry heat or steam autoclave. Each plier was subjected to a series of ligature wire cuts followed by the assigned sterilization method. The amount of wear at the tip of each plier in both groups was measured with a stereomicroscope system and digital photomicrography. Orthodontic ligature-cutting pliers with stainless steel inserts showed no significant difference in mean wear whether sterilized with steam autoclave or dry heat. Steam autoclave sterilization can be used with no significant deleterious effects on pliers with stainless steel inserts.

ORTHODONTIC WIRES:

Smith et al18 evaluated the effect of clinical use and various sterilization/disinfection protocols on three types of nickel-titanium, and one type each of β-titanium and stainless steel arch wire. The sterilization/disinfection procedures included disinfection alone or in concert with steam autoclave, dry heat, or cold solution sterilization. Load/deflection and tensile tests showed no clinically significant difference between as-received and used-then-disinfected/sterilized wires. Although sterilization of stain less steel wire is not of much use as most of them have bends and do not fit in another patients mouth but this is very useful in case of NITI wires as they do not have bends and can be reused. These results suggest that nickel-titanium arch wires can be recycled at least once. Mayhew and Kusy [19] studied the effects of sterilization on the mechanical properties and the surface topography of 0.017 ×0.025-inch Nitinol and Titanal arch wires. Three approved heat sterilization methods were used namely, dry heat applied at 180° C (355° F) for 60 minutes, formaldehyde alcohol vapor pressure of 20 to 25 psi for 30 minutes at 132° C (270° F) and steam autoclave at 121° C (250°F) and 15 to 20 psi pressure for 20 minutes. They concluded that neither the heat sterilization nor multiple cycling procedures had a deleterious effect on the elastic moduli, surface topography, or tensile properties of Nitinol or Titanal arch wires.The bending moduli and the tensile strengths were approximately 10% greater for Nitinol than for Titanal. Kapila, Haugen and Watanabe [20] determined the effects of in vivo recycling interposed by dry heat sterilization (together referred to as clinical recycling, CR) on the load-deflection characteristics of nickel-titanium alloy wires (Nitinol and NiTi). The results indicated that both dry heat sterilization (DHS) alone, as well as clinical recycling (CR), produced significant changes in the loading and unloading characteristics of Nitinol and NiTi wires.

LIGATURES

Metal and elastomeric ligatures are potential agents in the transmission of infectious diseases. Cross-contamination in handling elastomeric ligatures is a serious concern in the orthodontic office, since cold sterilization can damage the elastomeric material. Mulick [21] recommended single-use dispensing of elastomeric materials to eliminate contact of canesor sticks with contaminated hands. Schneeweiss [22] described a method of cutting elastomeric modules into smaller sections and covering them with clear tubing, which could then be cold sterilized. During arch wire placement, the operator contacts only the outside tubing while removing ligatures. The used section of ligatures is cut off and discarded after ligation

ORTHODONTIC BANDS

Preformed bands are first checked on the patient cast, if in case they don't fit intraorally then these tried bands are cleaned in ultrasonic cleaner and disinfected with disinfectant solution for recommended time as per manufacturer before placing it back in the box .

ELASTICS AND ELASTOMETRIC CHAINS:

5% Bibforte. Elastomeric Rings, Chains etc are sterilized by immersing in 5% Bibforte Solution for 30 Minutes. Vapoclave(ethylene oxide) is preferred for E-chain and ligature wires.Retrieved Arch wires, ligatures other sharps are treated with 5% Bibforte solution and dispatched to the central processing unit in plastic boxes

ORTHODONTIC BRACKETS AND BUTTONS:

Reuse is not advised as it may impair the performance and increase the risk of patient injury. Effects of recycling on metallic direct-bond orthodontic brackets was studied by Buchman. The methods of three recycling companies (Esmadent, Ortho-Cycle, and Ortho-Bonding) as well as the author's flame method were examined for their effects on bracket base torque, slot width, and mechanical properties. While it appeared that the amount of dimensional changes in the brackets after recycling is of little clinical signifficance, the changes in the metallurgic microstructure suggest susceptibility to metallic intergranular corrosion .

RUBBER ITEMS AND SALIVA EJECTORS:

Best method is to discard them after each use. Ethylene oxide sterilization is ineffective for rubber material and they may be damaged by dry or moist heat sterilization.

HAND PIECES:

 Steam, dry heat, chemical vapour and ethylene oxide sterilization are acceptable for hand pieces.

•Run the handpiece over a sink for 20 seconds allowing water to flush through the hand piece thoroughly. Remove the bur.

•Scrub the hand piece thoroughly with detergent and water, to remove any debris. Rinse and dry the hand piece.

•Lubricate the hand piece with a good quality oil recommended by the hand piece manufacture

•Expel excess oil by running the hand piece for 2 seconds, after replacing the bur or hanging the hand piece in a hand piece rack.

•Remove the bur, if replaced. Clean the fiber-optic, bundle ends with alcohol Place the hand piece in a clear view sterilisation pouch, together with a chemical indicator strip

•Sterilise in an autoclave or chemiclave, according to themanufacturer's instructions. Do not leave the handpiece in the steriliser after sterilisation cycle is complete.

•Remove the hand piece from the bag, insert the bur, and use.

ROTARY INSTRUMENTS

Burs become very contaminated and are classed as critical items; they must be sterilised after use. Diamond and carbide burs may be safely autoclaved with minimal damage but carbon-steel burs are damaged by autoclaving. Carbon-steel burs may be sterilised by using a chemical vapoursteriliser. A glass bead steriliser at 218ºC for 10 seconds may be used to sterilise grossly contaminated carbon-steel burs during the same dental procedure.

VISIBLE-LIGHT CURING UNITS

It has been shown that light curing devices are a potential source of transmission of infectious diseases, due to contamination of the light curing tip, which directly contacts oral structures, and the handle, which becomes contaminated with blood and saliva from the operator's or assistant's gloved hands. Some new designs of unit feature removable, autoclavable light curing tips. However, the handles still present a problem, since they cannot be sterilised. Units should be cleaned and disinfected with a phenolic disinfectant after use. Plastic units should be disinfected using an iodophor. Glutaraldehyde disinfectants have been found to damage the glass rods in a fiber-optic light tip, with a subsequent reduction in light output; the use of this disinfectant should be avoided.

Procedure

•Thoroughly wipe and clean the whole unit.

•If the fiber optic light tip can be sterilised, detach it and sterilise as recommended by the manufacturer.

•Wrap the handle and light curing tip (if not autoclavable) in a wrap, soaked with an iodophor disinfectant. The wrap should remain in place for at least 10 minutes or until the unit is next used.

•Remove the wrap and wipe the unit with distilled water to remove residual disinfectant.

•Some practitioners cover the top light curing tip with Clingfilm, which is removed after use

•Disposable protective coverings could be used on the handles, providing they do not interfere with the unit's cooling mechanism.

STONES:

For diamond stones dry heat , chemical vapour and ethylene oxide gas sterilization are preferred. For polishing stones chemical vapour and ethylene oxide sterilization are preferred. Polishing buff is disinfected by immersing it in CIDEX (2% glutaraldehyde) solution or alternatively in 5% Bibforte for 30 minutes.

IMPRESSION TRAYS:

For aluminum trays dry heat is not preferred. For chrome plated trays all methods of sterilization can be employed. For plastic or acrylic trays, ethylene oxide or gluteraldehyde sterilization is preferred.Stainless steel hand instruments can be sterilized by autoclave, dry heat, chemical vapour and ethylene oxide sterilization. Ultrasonic tip can be autoclaved but for ultrasonic cord preferred methods are vapoclave and gluteraldehyde. Tongue blade, lip and cheek retractors can be sterilized by steam or dry heat. Welder points sterilized preferably by vapoclav(ethylene oxide).

ORTHODONTIC MARKING PENCILS.

Conventional orthodontic marking pencils cannot be autoclaved. Gas sterilization, as used in this study, is effective in killing bacteria, but is also costly and difficult, making it impractical for orthodontic offices. One article has suggested alcohol-containing permanent markers as a safe and effective alternative to pencils, but this report also noted that the pens become increasingly ineffective in eliminating bacteria the longer they are used. Because alcohols are intermediate disinfectants that do not kill spores or certain viruses, the permanent markers may be unreliable infection-control devices. Soaking or spraying the tips of marking pencils with disinfectants could be more effective than wiping, but this method is unlikely to gain acceptance from practitioners. The only sure way to avoid potential cross-contamination is to use the inexpensive disposable markers available from orthodontic supply companies [24].

Orthodontic adhesives. Composites used as orthodontic direct bonding adhesives have a polymeric matrix that can host and nurture a variety of aerobic and anaerobic microorganisms acting alone or in combination. Their accumulation can lead to the weakening of the bond and possibly the attacking of the tooth. A number of microorganisms have been identified as present on the removed direct bonding brackets. Results of rendering the adhesive microbe-resistant by adding a bactericide have shown to be encouraging [25].

STERILIZATION REQUIREMENTS FOR THE PLACEMENT OF TEMPORARY ANCHORAGE DEVICE

According to the CDC, the placement of miniscrews in an orthodontic office is a surgical procedure. The following are the requirements for any oral surgical procedure: (1) perform surgical hand antisepsis with an antimicrobial product, (2) wear sterile surgeon’s gloves, (3) use sterile saline solution or sterile water as a coolant or irrigator, (4) use devices specifically designed to deliver sterile irrigating fluids, and (5) use packaged sterile instruments. In addition, to reduce the risk of postsurgical infection after implant placement, every load containing implantable devices should be monitored with a biologicial indicator (spore test) and avoid placing the device until after the results of the spore test are known. Because of the potential risk of infection from cutting or otherwise penetrating tissues that are not normally exposed, many precautions must be implemented to ensure patient protection.

List of the items needed to comply with sterilization guidelines:

(1) sterile implant;

(2) biological indicators;

(3) sterile instruments;

(4) pouches or central supply room wrap if using cassettes;

(5)Sharpie permanent marker 3601 or 13801 (Sanford LP, Oak Brook, Ill) (ink from this marker does not emit toxic fumes during sterilizing);

(6) antimicrobial soap or alcohol-based surgical hand rub;

(7) sterile, powder-free gloves for doctor and clinicians;

(8)clinic gown (disposable or a separate one for procedure);

(9)mask; and

(10) protective eyewear for doctor, clinician, and patient. Compliance with CDC guidelines and patient assurance of sterile instruments are necessary for using TADs in a practice