Sterilisation & disinfection /certified fixed orthodontic courses by Indian dental academy


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Sterilisation & disinfection /certified fixed orthodontic courses by Indian dental academy

  1. 1. STERLIZATION AND DISINFECTION INDIAN DENTAL ACADEMY Leader in continuing dental education
  2. 2. INTRODUCTION Dental care professionals are at an increased risk of cross infection while treating patients. • This occupational potential for disease transmission become evident initially when one realises that most human microbial pathogens have been isolated from oral secretions. Because of repeated exposure to micro-organisms in blood and saliva, incidence of certain infectious diseases has been significantly higher among dental professionals than observed for general
  3. 3. •Although there is common goal in infection control ,there are several approaches that may be used to achieve the desired result.These approaches vary from office to office depending on type of dental procedure performed ,number and training employees,and type of equipment used.
  4. 4.  Part of the problem lies in the fact that many practitioners and auxillaries previously failed to appreciate the infection potential presented by saliva and blood during treatment.  These dangers often we dismissed because much of spatter coming from patients mouth is not noticed readily.
  5. 5. HISTORY  The science of microbiology has shed much light on the nature of disease. In the nineteenth century the work of Pasteur ,Lister and Koch did much to explain the role of bacteria in disease and to indicate possible methods of practicing safer medicine.  LOUIS PASTEUR (1822-95) was the first scientist to show clearly that bacteria never generate spontaneously and that no growth of any kind occurs in the sterilized media.
  6. 6.  One of his many achievements was the development of the technique of controlled heating known as ‘PASTEURISATION’ for the preservation of beverages and food stuffs.  By his experimental studies on anthrax in 1876-77, he was to prove that a certain type of infection invariably occurred when a number of micro-organisms of a particular kind were introduced to the body..
  7. 7. If I had the honour of being a surgeon, impressed as I am with the dangers of exposure to the microbes scattered of all objects, not only would I use perfectly clean instruments,but after washing my hands with greatest care and submitting them to rapid flaming, I would use bandages,previously exposed in air at 130-150 degreeand use water which has been submitted to a temp of 120 degree….this way I would have to fear only the germs suspended in the air around the patients bed.” Louis Pasteur(1878)
  8. 8. Dr. Joseph Lister (1827-1912) Discovered the effectiveness of 'carbolic acid,‘ which was used in controlling typhoid. • Using carbolic acid, Lister was able to keep his hospital ward in Glasgow free of infection for nine months. • Lister published the results of his experiments in The Lancet : 11 cases of compound fracture without any sepsis.
  9. 9. Carbolic acid spray being used at the time of a surgery
  10. 10. Influx model carbolic spray, copper, brass with wood handle 
  11. 11.  Robert Koch (1843-1910) was one of the greatest figures in the development of microbiology. He had immense skill in devising new bacteriological techniques. He was also the first to make photomicrographs of stained smears, and in addition he pioneered methods of growing bacteria on agar media.
  12. 12.  Despite the fact that the germ theory of disease had been established in 1877, it was not universally accepted until 1882 when Koch presented his masterly paper on ‘The aetiology to tuberculosis’ giving details of the isolation of the tubercle bacillus. In the following year he isolated the cholera vibrio.  The ‘Golden era’ of medical microbiology which was opened by Pasteur, Lister and Koch was perhaps the greatest contribution ever to the theory and practice of medicine.
  13. 13. Antonie van Leeuwenhoek in 1683 was the first to describe microorganisms in human mouth. -His astute observation on scrapings from carious cavities in teeth were made with the use of only a single-lens microscope. - But despite such limitations he was able to describe the principle shapes of bacteria that remains the basis for much of the classification of microorganisms today. Microbiology in Dentistry
  14. 14. DEFINITIONS . STERILISATION: The process by which an article surface or medium is freed of all microorganisms, either in the vegetative or spore state. DISINFECTION: The destruction of all pathogenic micro organisms or organisms capable of giving rise to infection.
  15. 15. ANTISEPTICS: Chemical disinfectants, which can be safely applied to skin or mucous membrane surfaces and are used to prevent infection by inhibiting the growth of bacteria. BACTERICIDAL AGENTS: Agents able to kill bacteria. BACTERIOSTATIC: Agents preventing only the multiplication of bacteria, which may remain
  16. 16. Goal of sterilization and infection control Most microbes that we come in contact do us no harm. Others colonize and become established as our commensal flora, yet others establish infection. Factors determining the development of infectious disease -virulence -dose -resistance Health or disease=virulence x dose ----------------------- resistance
  17. 17. Virulence of micro-organisms in their natural environments cant be changed Resistance to diseases can be enhanced by immunization but not for all diseases The only disease determinant we can effectively manage is the dose, and the management of the dose is called as infection control.
  18. 18. INSTRUMENT PROCESSING  Instrument processing is the procedures that prepares contaminated instruments for reuse. The processing must be performed carefully so that disease agents from a previous patient, or from a member of the dental team who handled the instruments, or from the environment will not be transferred by the instruments to the next patient. Processing also must be performed correctly to keep instrument damage to a minimum.
  19. 19. Instrument processing steps 1. Holding (presoaking) 2. Precleaning. 3. Corrosion Control, Drying, Lubrication 4. Packaging 5. Sterilization 6. Sterilization monitoring 7. Handling Processed Instruments
  20. 20. I. HOLDING (PRESOAKING)  This can facilitate the actual cleaning.  Extended presoaking for more than a few hours is not recommended, for this may enhance corrosion of some instruments.  The holding solution may be the same as that to be used for ultrasonic cleaning or it may be a germicidal solution (e.g., a glutaraldehyde) indicated for instrument immersion.  If instruments cannot be cleaned soon after use, place them in a holding solution to prevent drying of
  21. 21. ii. PRECLEANING:  Ultrasonic cleaning :  Ultrasonic cleaning, compared with scrubbing instruments by hand, reduces direct handling of the contaminated instruments and the chances for cuts and punctures.  Exception is some high-speed hand pieces.  The time required ranges from about 5 to 15 minutes.
  22. 22. Manual scrubbing of instruments  Scrubbing contaminated instruments by hand is a very effective method of removing the debris if performed properly.  -All surfaces of all instruments should be thoroughly brushed while the instruments are submerged in a cleaning solution to avoid spattering.  -This is followed by thorough rinsing with a minimum of splashing.
  23. 23. III. CORROSION CONTROL, DRYING, AND LUBRICATION  Instruments or portions of Instruments and burs made of carbon steel will rust during steam sterilization.  Examples might be nonstainless steel cutting or scraping Instruments such as scalers, hoes, and the cutting surfaces of orthodontic pliers.  Although rust inhibitors (e. g., sodium nitrite) that can be sprayed on the Instruments will reduce rusting of some of these items, the best approach is not to process such items through steam.  Instead, thoroughly dry the Instruments and use dry heat or unsaturated chemical
  24. 24. IV :Packaging  Packaging Instruments before processing through the sterilizer prevents them from becoming contaminated after sterilization during storage or when being distributed to chairside. Packaging involves organizing the Instruments in functional sets and wrapping them or placing them in sterilization pouches, bags, trays, or cassettes.
  25. 25.  Wrapping or Bagging :  Functional sets of instruments can be placed on a small sterilizable tray and the entire tray wrapped with sterilization wrap.Seal the wrap with tape that will withstand the heat process. (e.g., “autoclave tape”).
  26. 26.  Using Cassettes :  Numerous styles of cassettes are available that contain functional sets of instruments during use at chairside and during the ultrasonic precleaning, rinsing, and sterilizing processes.  - Using cassettes reduces the direct handling of contaminated instruments and keeps the instruments together through the entire
  27. 27.  Unwrapped Instruments :  Sterilizing unpackaged instruments is the least satisfactory approach to patient protection because it allows for unnecessary contamination before the Instruments are actually used on the next patient
  28. 28. METHODS OF STERILIZATION 1)Heat sterilization 2)Gas or ethylene oxide sterilization 3)Liquid chemical sterilization and disinfection
  29. 29. HEAT STERILISAION Heat sterilization is the most common type of sterilization technique used today. Heat sterilization involves a) Steam sterilization b) Dry heat sterilization c) Unsaturated chemical vapour sterilization
  30. 30. Moist heat  Temperatures below 1000C/ pasteurization  Temperatures at 1000C/ boiling  Steam at atmospheric pressure
  31. 31. Pasteurization ( below 1000C ) Purpose – To reduce the bacterial population of a liquid such as milk Spores are not affected by pasteurization  Holding method :- 62.90C for 30 min  Flash pasteurization :- 71.60C for 15sec 0
  33. 33. Steam sterilization  Steam under pressure has a higher temperature than 100 C  To be effective against viruses and spore forming bacteria it needs to have steam in direct contact with material  Autoclaves are highly effective and inexpensive
  34. 34. Characteristics :  Temperature : 121 C (250 F)  Pressure : 15 psi  Cycle time: 15-20 minutes  Acceptable Materials: Paper, plastic, cloth, or paper peel pouches  Unacceptable Materials: closed metal and glass containers
  35. 35. dvantages: Short efficient cycle time Good penetration Ability to process a wide range of materials without destruction isadvantages: Unsuitable for heat sensitive objects Corrosion of unprotected carbon steel instruments Dulling of unprotected cutting edges Possibility that packages may remain wet at end of cycle
  36. 36. Dry heat DIRECT FLAME Bunsen burner
  37. 37. Incineration
  38. 38. dry heat sterilization Sterilization of instruments with dry heat is the least expensive form of heat sterilization. A complete cycle involves heating the oven to the appropriate temperature and maintaining that temperature for a proper interval.
  39. 39. Characteristics :  Temperature :160 C (320 F) Or 170 C (340 F)  Cycle time : 2 hours Or 1 hour Requirements:  Must not insulate items from heat  Must not be destroyed by temperature used Acceptable Materials: Paper bags, aluminum foil, polyfilm plastic tubing Unacceptable Materials : plastic and paper bags that cannot withstand dry heat temperature
  40. 40. Advantages:  -Is effective and safe for sterilization of metal instruments and mirrors .  -Does not dull cutting edges .  -Does not rust or corrode Disadvantages :  -Requires long cycle for sterilization  -Has poor penetration  -May discolor and char fabric  -Destroys heat-labile items  -Cannot sterilize liquids  -Is generally unsuitable for
  41. 41. (iii) RAPID HEAT TRANSFER STERILIZATION : Characteristics :  Temperature : 190 C (375 F)  Cycle time : 12 minutes for wrapped items ; 6 minutes for unwrapped items. Acceptable Materials: Paper bags, aluminum foil, polyfilm plastic tubing Unacceptable Materials : Plastic and paper bags that cannot withstand dry heat
  42. 42. Advantages:  -It has a shorter cycle time than regular dry heat units.  -Items are dry after cycle  -It does not dull cutting edges Disadvantages:  -Instrument must be dried before packaging and placement in chamber.  -It destroys heat-labile items  -It cannot sterilize liquids  -It is generally unsuitable for dental handpieces  -Unwrapped items become contaminated quickly after the cycle.
  43. 43. (c)Unsaturated chemical vapour sterilization  Depends on heat, water and chemical synergism for its efficacy  A solution of alcohol, formaldehyde, ketone, acetone and water is used to produce a sterilizing vapour
  44. 44. Characteristics: Temperature: 131 c pressure: 20 psi Cycle time: 20-40 mins  Packaging material requirements : Vapors must be allowed to precipitate on contents Plastics should not contact the sides of sterilizer  Acceptable materials: Perforated metal trays, paper or paper peel pouches  Unacceptable materials :solid metal trays and sealed glass
  45. 45.  Advantages: -It has short cycle time -it does not rust or corrode metal instruments including carbon steels -it does not dull cutting edge -it is suitable for orthodontic stainless steel wires Disadvantages: -Instruments must be dried completely before processing -A special chemical solution must be used -It will destroy heat sensitive plastics -There is a chemical odour in poorly ventilated areas -It can not steriize
  47. 47. GAS STERILIZATION Ethylene oxide: The use of ETO is recognized by the American Dental association (ADA) and Centers for Disease control and prevention (CDC) as an acceptable method of sterilization for the following items:
  48. 48. i) those that can be damaged by heat and/ or moisture, ii) and those that can be cleaned and dried thoroughly.. This chemical is effective as a virucidal agent, is sporicidal, does not damage materials, and can evaporate without residue
  49. 49. CHARACTERISTICS Temperature : room temperature (250C/750F) Cycle time : 10-16 hours (depending on material) Acceptable materials : paper, plastic bags Unacceptable materials : sealed metal or glass containers
  50. 50. Advantages: -High capacity for penetration -Does not damage heat-labile material -Evaporates without leaving a toxic residue -Suitable for materials that cannot be exposed to moisture
  51. 51. Disadvantages: -Slow, requires long cycle time -Uses toxic/hazardous chemical -Items must be cleaned and dried thoroughly before exposure. -Causes tissue irritation if not well aerated
  52. 52. LIQUID CHEMICAL STERILIZATION AND DISINFCTION  Inexpensive and suitable for heat sensitive items  Toxic and irritant  2% glutaraldehyde is most widely used, Often used as disinfectants but can also sterilize instruments if used for prolonged periods  liquid sporicidal chemical  Most bacteria and viruses are killed within 10 minutes  Spores can survive several
  53. 53. RECENT ADVANCES  Low temperature sterilization involves vaporized H2O2  Bead sterilizers Size of glass beads – 1.2 to 1.5mm Temperature - 4240 to 4500F Time - 3 to 5sec Disadv ; uneven temperatures  Hot oil sterilization - mineral oil
  54. 54. Physical control by other methods
  56. 56. Selection of antiseptics & disinfectants Prerequisites  It should have a wide spectrum of activity  Fast acting  Active in the presence of organic matter  Nontoxic to animals or humans ( antiseptic )  Soluble in water  It should not separate on standing  Should have high penetrating power  Surface compatibility  Relatively
  57. 57. Factors  Concentration of the substance  Time  pH of the medium  Temperature  Nature of microorganism  Surface to be treated  Presence of extraneous material
  58. 58. Levels of disinfection 1. High - sterilizing agents ex; ethylene oxide gas 2. Intermediate - bactericidal agents ex; formaldehyde, alcohols 3. Low - narrowest anti-microbial activity ex; soaps, detergents
  59. 59. Mechanisms of anti-microbial action  Agents that interfere with membrane function  Agents that denatures proteins  Agents that destroy or modify the functional groups of proteins
  60. 60. Agents that interfere with membrane function  Surface active agents  Phenols  Alcohols
  61. 61. Surface active agents “Substances which alter energy relationship at interfaces producing a reduction of surface or interfacial tension”  Anionic  Cationic  Nonionic  Amphoteric
  62. 62.  Cationic detergents – quaternary ammonium compounds Ex; Acetyl trymethyl ammonium bromide & Benzalkonium chloride Disadvantages - Inability to penetrate organic debris - Incompatibility with anionic agents
  63. 63.  Anionic detergents – Soaps &fatty acids  Nonionic detergents – Tween 80 relatively non toxic  Amphoteric compounds – ‘TEGO’ compounds
  64. 64. Soap – A chemical compound of fatty acids combined with potassium or sodium hydroxide  pH - 8.0  Mechanical removal of organisms  Wetting agents  Reduce surface tension
  65. 65. PHENOL DERIVATIVES  CRESOLS - Greater germicidal activity & lower toxicity  BISPHENOLS - 2 phenol molecules ex; Hexachlorophene, Chlorhexidine FDA ( 1976 ) approved as a surgical scrub, hand wash, superficial skin wound cleanser
  66. 66. Phenols and Derivatives :  This phenolic solution was used as an all-purpose surgical instrument immersion steriliant, hand washing antiseptic, wound cleaner, and preparatory antimicrobial for surgical sites...  These agents act as cytoplasmic poisons by penetrating and disrupting microbial cells walls, leading to denaturation of intracellular proteins.  The intense penetration capability of phenols is probably the major factor associated with their anti microbial activity .  Thus, with the exception of the bisphenols, most phenolic derivatives are used as disinfectants
  67. 67. ALCOHOLS Effective skin antiseptics  Ethyl alcohol - Denatures proteins and dissolves lipids - Dehydrating agent Readily reacts with organic matter  Isopropyl alcohol  Methylalcohol
  68. 68. Alcohols: - Ethyl alcohol and isopropyl alcohol have been used extensively for many years as skin antiseptics and surface disinfectants. - Ethyl alcohol is relatively nontoxic, colorless, nearly odorless and tasteless, and readily evaporates without residue. - Isopropyl alcohol is less corrosive than ethyl alcohol because it is not oxidized as rapidly to acetic acid and acetaldehyde.
  69. 69. Disadvantages : -Not sporicidal -Damaging to certain materials, including rubber and plastic -Rapid evaporation rate with diminished activity against viruses in dried blood, saliva, and other secretions on surfaces
  70. 70. Agents that denatures proteins Ex; Acids Alkalies Alcohols Acetone Organic solvents
  71. 71. ACIDS & ALKALIES Free H+ and OH- ions Ex; benzoic acid, propionic acid Acids are valuable adjuncts to disinfection
  72. 72. Agents that destroy or modify the functional groups of proteins  Mercuric compounds – sulphydryl groups  Anionic detergents - amino & imidazole groups Ex; heavy metals halogens hydrogen peroxide
  73. 73. Heavy metals ‘An electron donating element whose atoms are large, with complex electron arrangements’ eg, mercury, copper, silver
  74. 74. Mercury (Hgcl2) - Skin diseases - Toxic to the host - antimicrobial activity is reduced in the presence of organic matter Copper - chlorophyll containing organisms - CuSO4 is a potent inhibitor of algae
  75. 75. Silver - AgNO3 - antiseptic & disinfectant - 1% AgNo3 solution is active against Neisseria Gonorrhoeae infection -used to disinfect suturing threads -Not sporicidal
  76. 76. Halogens – ‘A group of highly reactive elements whose atoms have 7 electrons in the outer shell’ Chlorine – gasseous form, organic & inorganic forms. chlorine is available in 3 other forms 1. Hypochlorites Organic chloramines Inoganic
  77. 77. Chlorine compounds 1.Ca(Ocl)2 - Chlorinated lime 2. NaOCl - DAKIN’s solution used to treat ‘ATHLETE’s foot 3. Clorax & Purex bleach 4. Chloramines – Chloramine-T
  78. 78. Iodine and Iodophors :  Iodine is one of the oldest antiseptics for application onto skin, mucous membranes, abrasions, and other wounds.  high reactivity of this halogen with its target substrate gives it potent germicidal effects.  It acts by iodination of proteins and subsequent formation of protein salts. Tinctures of iodine are toxic for gram-positive and gram-negative bacteria, tubercle bacilli, spores, fungi, and most viruses.
  79. 79. Iodine More reactive than chlorine Halogenating tyrosine portions of protein molecules Tincture of iodine –2% iodine solution in ethyl alcohol
  80. 80. - Iodophor antiseptics are useful in preparing the oral mucosa for local anesthesia and surgical procedures. - Their surfactant properties make them excellent cleaning agents before disinfection, and newer iodophor commercial formulations have shown EPA-approved tuberculocidal activity within 5 to 10 minutes of exposure.
  81. 81.  Iodophors ‘Iodine detergent complexes that release iodine over a long period of time’ Advantage – no staining of tissues or fabrics Ex; wescodyne - preoperative skin preparation Betadine - presurgical scrubbing Ioprep - local wound antiseptic
  82. 82. Hydrogen peroxide ( H2O2 )  A simple chemical compound digested by catalase to water and oxygen  Mechanical removal of microorganisms  New forms – super D H2O2
  83. 83. ALKYLATING AGENTS  Formaldehyde  Ethylene oxide  Gluteraldehyde
  84. 84. Formaldehyde Gas at high temperatures & a solid at room temperatures 37% solution – Formalin In gaseous form - Sterilize surgical equipment & medical instruments 20% solution in 70% alcohol for 18hrs – to sterilize instruments -Causes Contact dermatitis
  85. 85. Ethylene oxide  Toxic & Highly explosive  Cold burns
  86. 86. Gluteraldehyde  Activity will not reduce in the presence of organic matter  It does not damage delicate objects  Irritating fumes  Discoloration & corrosion of instruments
  87. 87. 2.0 to 3.2% glutaraldehyde is used to sterilize and disinfect. At these concentrations, - glutaraldehydes can be effective against vegetative bacteria, including M. Tuberculosis, fungi and viruses, and can destroy microbial spores after a 10-hour immersion period.. - In fact, glutaraldehydes are useful in decontaminating certain types of dental impression materials.
  88. 88. Disadvantages : - Although glutaraldehyde formulations are effective as immersion steriliants/ disinfectants, they are also extremely toxic to tissues. - Irritation of hands and discoloration of cuticles are common sequelae when people do not wear appropriate utility gloves. - damage to respiratory and olfactory tissues and ocular injury
  89. 89. iii) Physical Monitoring :  Physical monitoring of the sterilization process involves observing the gauges and displays on the sterilizer and recording the sterilizing temperature, pressure and exposure time.  -It must be remembered that sterilizer gauges and displays indicate the conditions in the sterilizer chamber rather than conditions within the packs, pouches or cassettes being processed.  -Thus, physical monitoring may not detect problems resulting from overloading, improper packaging material or use of closed
  90. 90. VII. HANDLING PROCESSED INSTRUMENTS :  Instrument sterility should be maintained until the sterilized packs, pouches or cassettes are opened for use at chairside. i) Drying and Cooling :  Packs, pouches or cassettes processed through steam sterilizer may be wet and must be allowed to dry before handling
  91. 91. ii) Storage :  Handling of sterile packages should be kept to a minimum , and those that are dropped on the floor, torn, compressed or become wet must be considered as contaminated  -Store sterile packages in dry, enclosed, low-dust areas away from sinks and water pipes .This prevents packages from becoming wet with splashed water.  -And store the packages away from heat sources that may make the packaging material brittle and more susceptible to tearing or puncture. iii) Distribution :  Instruments from sterile packs or pouches can be placed on sterile, disposable, or at least cleaned and disinfected trays at chairside.  -Sterilized instrument cassettes are distributed to and opened at chairside
  92. 92. INSTRUMENT PROTECTION:  Instrument processing can cause damage to instruments, but several steps could be taken to keep this at a minimum.  Stainless-steel instruments are least effected by corrosion from moisture and heat, but some clinicians prefer instruments with carbon steel rather than stainless-steel cutting surfaces that may retain a sharp edge longer.  Unfortunately, carbon steel items corrode and lose sharpness during sterilisation. Carbon steel items are best sterilized in a non-corrosion producing environment
  94. 94. Items Recommended covering Chair back (optional) Plastic Headrest (only if not covered along with chair back) Plastic Dental unit, including hose supports Plastic Side auxiliary support surfaces Plastic Air-water syringe handle Plastic High-volume evacuation control Plastic Saliva ejector control Plastic Lamp handles Foil, plastic wrap, or bag Light communication system Plastic Drawer handles Plastic
  95. 95. Systemic diseases with pathogens present in blood and other body fluids Disease Pathogen Hepatitis B Hepatitis B virus Hepatitis C Hepatitis C virus Hepatitis D Hepatitis D virus HIV-infection and AIDS Human immunodeficiency virus BLOODBORNE PATHOGENS AND OTHER DISEASE AGENTS : The patient’s mouth is the most important source of potentially pathogenic microorganisms in the dental office. Pathogenic agents may occur in the mouth as a result of four basic conditions: Bloodborne diseases, Oral diseases, Systemic diseases with oral lesions, and Respiratory diseases.
  96. 96. •Bloodborne pathogens may enter the mouth during dental procedures that induce bleeding. • Thus contact with saliva during such procedures may result in exposure to these pathogens if present. Because it is very difficult to determine if blood is actually present in saliva, saliva from all dental patients should be considered as potentially infectious.
  97. 97. A B C D E Other name Infectious Serum Parenterally transmitted non-A, non- B Delta Enterically transmitted non-A, non- B Major route of transmission Fecal-oral, water, food Parenteral, direct contact Parental, direct contact Parental, direct contact Fecal-oral, water, food Incubation 2-6 weeks 4-24 weeks 2-20 weeks 4-24 weeks Unknown Liver necrosis Rare Uncommon Uncommon Yes Unknown Chronicity No Yes (5-10%) Yes (50%) Yes No VIRAL HEPATITIS
  98. 98. Risk for the dental team : Risk for dental patients: Hepatitis B vaccine: •We are extremely fortunate that safe and effective vaccines for hepatitis B are available. •Because there is no successful medical treatment to cure this disease, prevention is of paramount importance. •The vaccine is strongly recommended for all members of the dental team. HEPATITIS B VIRUS
  99. 99. HIV INFECTION AND AIDS Oral manifestations of AIDS : Early manifestations of AIDS occur as oral lesions. •Oral manifestations include fungal diseases, such as candidiasis, histoplasmosis, geotrichosis, or cryptococcosis; •viral diseases such as warts, hairy leukoplakia, or herpes simplex infection; • bacterial diseases such as rapidly progressing periodontitis or gingivitis; • cancerous disease such as Kaposi’s sarcoma and non- Hodgkin’s lymphoma. Transmission : •Intimate sexual contact (vaginal, anal, oral) involving contact or exchange of semen or vaginal secretions; •Exposure to blood, blood-contaminated body fluids, or blood products; •Perinatal contact (from infected mother to child
  100. 100. Exposure to blood : HIV INFECTION AND AIDS
  101. 101. Prevention : Sexual contact : HIV INFECTION AND AIDS Recommendations for preventing the spread of HIV-1 through sexual contact includes abstinence or limiting sexual activities to one partner who is not infected and who does not have any other sex partners
  102. 102. -All members of the dental team and other health-care workers must protect themselves from exposure to blood, saliva and other potentially infectious body fluids. - Contaminated sharps must be handled and disposed of properly. -Gloves, mask, and protective eyewear and clothing must be used during the care of all patients and in other instances to prevent direct or indirect contact with body fluids. - Also, all health-care workers must prevent their blood or body fluids from coming into contact with the patients being treated, and instruments and equipment used on more than one patient must be properly decontaminated before reuse. - Injection drug abusers must not use blood-contaminated needles. Blood contact :
  103. 103. Diseases Pathogen Herpes infections Herpesvirus hominis (herpes simplex virus) Syphilis Treponema pallidum Hand-foot-mouth disease Coxsackievirus Herpangina Coxsackievirus Gonococcal pharyngitis Neisseria gonorrhoeae Candidiasis Candida albicans ORAL DISEASES
  104. 104. I) HERPES INFECTIONS : Herpes simplex viruses may cause infections of the mouth, skin, eyes and genitals. -About 90% of adults have been infected with herpes simplex virus type 1, but only 10% (usually children) experience the typical symptoms of oral herpes (primary herpetic gingivostomatitis). -In this disease, vesicle-type lesions occur in the mouth. -Vesicles during active herpes simplex infections at any site of the body contain the virus which may be spread to others by direct contact with these lesions. -Also, the herpes simplex virus may be present in saliva in those with oral or lip lesions and possibly in a small percent of those who are infected but have no active lesions. -In such instances, sprays or aeorosols of the saliva may result in spread of the virus to unprotected eyes of the dental
  105. 105. II) HERPANGINA AND HAND-FOOT-MOUTH DISEASE : Herpangina appears as vesicles on the soft palate or elsewhere in the posterior part of the mouth that break down to ulcers that last for about a week. -Fever, sore throat and headache frequently accompany the vesicular stage. -The lesions are caused by specific types of coxackie virus.
  106. 106. III) ORAL SYPHILIS . Treponema pallidum is a spirochete bacterium and is the causative agent of syphilis. -About 5-10% of the cases of syphilis first occur in the mouth in the form of a lesion called a primary chancre, an open ulcer frequently on the tongue or lips. -These lesions do contain the live spirochetes and may be spread by direct contact. - The possibility of the spirochete entering small cuts or breaks in the skin of unprotected hands of the dental team exists and has been documented in one instance causing syphilis of the finger.
  107. 107. IV) ORAL CANDIDIASIS : Candida albicans is a yeast that occurs in the mouth asymptomatically in about one third of adults. -Such circumstances that may result in oral disease called thrush or oral candidiasis might include conditions that disturb our body defense mechanisms such as the systemic diseases of HIV infection, and leukemia; -Spread of C. albicans from a patient’s mouth to the dental team is theoretically possible through direct contact with lesions or sprays or aerosols of infected saliva.
  108. 108. IMMUNIZATION FOR ORAL HEALTH CARE PROVIDERS Health care workers are at particular risk of several vaccine-preventable diseases.
  109. 109. Generic name Primary schedule and Boosters (s) Hepatitis B recombinant DNA Two doses IM 4 weeks apart, third dose 5 months after second Rubella live virus vaccine One dose SC, no booster Measles live virus vaccine One dose SC, no routine boosters Mumps live virus vaccine One dose SC, no booster Influenza vaccine (inactivated whole- virus and split-virus vaccine) tetanus – diptheria toxoid Annual vaccination with current vaccine. Either whole or split virus vaccine may be used two doses IM 4 weeks apart, third dose 6to 12 months after second dose, booster every 10 years. Enhanced – potency inactivated poliovirus vaccine (E-IPV) live oral polio virus vaccine (OPV) E-IPV is preferred for primary vaccination of adults, two doses SC 4 to 8 weeks apart, a third dose 6 to 12 months after the second. For adults with a completed primary series and for whom a booster is indicated, either OPV or E-IPV can be given Recommended vaccines for Oral Health care Workers
  110. 110. PATHWAYS FOR CROSS-CONTAMINATION A total office infection program is designed to prevent or at least reduced the spread of disease agents from: •Patient to dental team; •Dental team to patient; •Patient to patient; •Dental office to community, including the dental team’s families.
  111. 111. i) Patient to Dental Team: • Direct contact : with patient’s saliva or blood may lead to entrance of microbes through a nonintact skin resulting from cuts, abrasions, or dermatitis. • Droplet infection: They occur as a result of sprays, spatter or aerosols from patients mouth. • Indirect contact: involves transfer of microorganisms from the source (e.g., the patient’s mouth) to an item or surface and subsequent contact with the contaminated item or surface. • Examples include cuts or punctures with contaminated sharps (e.g. instruments, needles, burs, files scalpel blades, wire) and entrance through nonintact skin as a result of touching contaminated instruments, surfaces or other item.
  112. 112. ii) Dental Team to Patient : Spread of disease from the dental team to patients is indeed a rare event, but could happen if proper procedures are not followed. -If the hands of dental team member contain lesions or other nonintact skin. - if the hands are injured while in the patient’s mouth, bloodborne pathogens or other microbes could be transferred by direct contact with the patient’s mouth, and they may gain entrance through the patient’s mucous membrane. - If a member of the dental team bleeds on instruments or other items that are then used in the patient’s mouth, cross infection may result.
  113. 113. iii) Patient to patient : Disease agents might be transferred from patient to patient by indirect contact through improperly prepared instruments, hand- pieces and attachments or surfaces.
  114. 114. iv) Dental Office to Community : This pathway may occur if microorganisms from the patient contaminate items that are sent out or are transported away from the office. For example, contaminated impressions or appliances or equipment needing service may in turn indirectly contaminate personnel or surfaces in dental laboratories and repair centers. Dental laboratory technicians have been occupationally infected with hepatitis B virus (HBV). This pathway also may occur if members of the dental team transport microorganisms out of the office on contaminated clothing. In addition, if a member of the dental team acquires an infectious disease at work, the disease could be spread to personal contacts with others outside the office. Also, regulated waste that contains infectious agents and is transported from the office may contaminate waste haulers if it is not in proper containers.
  115. 115. Items Recommended covering Chair back (optional) Plastic Headrest (only if not covered along with chair back) Plastic Dental unit, including hose supports Plastic Side auxiliary support surfaces Plastic Air-water syringe handle Plastic High-volume evacuation control Plastic Saliva ejector control Plastic Lamp handles Foil, plastic wrap, or bag Light communication system Plastic Drawer handles Plastic
  116. 116. PERSONAL PROTECTIVE EQUIPMENT AND BARRIER TECHNIQUES Oral health care providers and their patients may be exposed to a variety of microorganisms via blood or oral and respiratory secretions. - Infections can be transmitted in the oral health care setting through direct contact with blood, saliva, and other secretions ; - Indirect contact with contaminated instruments, operatory equipment, and environmental surfaces ;
  117. 117. Gloves : . For the protection of oral health care personnel and the patient, medical gloves always must be worn when there is a potential for contacting blood, blood-contaminated saliva, or mucous membranes.When asepsis is of prime concern wearing two pair of gloves is recommended.since microorganisms multiply rapidly in the environment under gloves, handwashes containing 4% chlorhexidine are recommended. . .
  119. 119. Masks : When a tooth is cut with a high-speed turbine handpeice or cleaned with an ultrasonic scaler, blood, saliva, and other debris are atomized and expelled from the mouth. -Masks that cover the mouth and nose reduce inhalation of potentially infectious aerosol particles. -They also protect the mucous membranes of the mouth and nose from direct contamination. - Masks should be worn whenever aerosols or spatter may be generated.
  120. 120.  MASK SHOULD FILTER
  121. 121. Protective eyeglasses : During dental procedures, large particles of debris and saliva can be ejected towards the oral health care provider’s face. - These particles can contain large concentrations of bacteria and can physically damage the eyes. -Protective eyewear is indicated, not only to prevent physical injury, but also to prevent infection.
  122. 122.
  124. 124. DISPOSAL OR WASTE MATERIALS:- - Gloves, masks, wipes, paper drapes:- Handled with gloves, discarded in impervious plastic bags. - Blood, disinfectants, sterilants:- Carefully poured into a drain connected to a sanitary server system. - Sharp items, needles, blades, scalpels:- Puncture- resistant containers marked with biohazard label. - Human tissue:- Same as sharp items, but diff. containers.
  125. 125.
  126. 126. INFECTION CONTROL CONSIDERATIONS IN DENTAL OFFICE DESIGN Additionally, the total square footage and layout of the entire space should not be negotiated until each work area has been evaluated. Considering that the clinical arena is the most affected by infection control, the following elements should be evaluated in regard to the overall health and safety of the person performing the task. 1)Office flow 2)Cabinetry. 3)Laminate, wall, and floor coverings 4)Ventilation.
  127. 127. 1) Office flow : The layout of the entire office should incorporate a smooth efficient operational flow. For example, patients have direct access to the treatment rooms and consultation areas from the reception area without having to pass through instrument processing areas. 2) Cabinetry : The number of drawers and their contents should be minimized to simplify cleanup procedures and reduce possible cross-contamination by the temptation to reach into the drawer during a procedure. -Treatment room cabinetry should be positioned on both sides of the patient’s chair. This will allow both the doctor and assistant access to essential side support areas and provide flexibility to both right and left-handed clinicians working in the same space.
  128. 128. 3)Laminates and wall and floor coverings : Although patient appeal and aesthetics continue to be a consideration, cabinetry surfaces and wall and floor coverings are a primary concern. Wood surfaces, heavily textured wall coverings, and fabrics for decoration should be eliminated. Smooth, seamless, nonporous materials will inhibit the collection of microbes and, therefore, also should be considered. 4) Ventilation : Work areas must have positive ventilation to control noxious vapors form various chemicals used in laboratory and sterilization areas. Additionally, considering that microbes inevitably are transported from one area to another via ventilation systems, these systems must be designed to prevent recirculation of contaminated air.
  130. 130. • Bellavia De : Efficient and effective infection control. J Clin Orthod 1992; 26: 46- 54. • Buckthal JE, Maynew MJ, Kusy RP : Survey of sterilization and disinfection procedures. J Clin Orthod 1986; 20: 759-765. • Cash RG : Trends in sterilization and disinfection, procedures in orthodontic offices. Am J Orthod Dentofacial Orthop 1990; 98: 292-299. • Cohen KL, Helen G : Disease prevention and oral health promotion. • Compbell PM, Phenix N : Sterilization in orthodontic office. J Clin Orthod 1986; 20: 684-686. • Cottone AJ : Practical infection control in dentistry. • Council on Dental materials and council on dental therapeutics : Infection control in dental office. J Am Dental Assoc 1978; 97: 673-677. • Ascencio F, Langkamp H, Agarcoal S : Orthodontic marking pencils as a potential source of cross contamination. J Clin Orthod 1998; 32: 307-310.
  131. 131. • Dental Clinics of North America (1991) : Infection control and office safety • Dental Clinics of North America (1996) : Infectious diseases and dentistry. • Dental Clinics of North America (July 2003) : Infections and infectious diseases – Part I. • Dental Clinics of North America (Oct 2003) : Infections and infectious diseases – Part II. • Drake DL : Optimizing orthodontic sterilization techniques. J Clin Orthod 1997; 31: 491-498. • Jones M, Pizarro K, Blunden R : Effect of routine steam autoclaving on orthodontic pliers. Eur J Orthod 1993; 15: 281-290. • Lee SH, Chang Y : Effects of recycling on the mechanical properties and surface topography of nickel-titanium alloy wires. Am J Orthod Dentofacial Orthop 2001; 120: 654-663. • Matasa CG : Orthodontic recycling at crossroads. J Clin Orthod 2003; 37: 133- 139. • McCarthy GM, Mamandras AH, Mac Donald JK : Infection control in orthodontic office in Canada. Am J Orthod Dentofacial Orthop 1997; 112: 275- 81.
  132. 132. Thank you For more details please visit