Radiation hazards &infection control in orthodontics / orthodontic courses by indian dental academy


Published on


The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and offering a wide range of dental certified courses in different formats.
for details pls visit www.indiandentalacademy.com

  • Be the first to comment

No Downloads
Total views
On SlideShare
From Embeds
Number of Embeds
Embeds 0
No embeds

No notes for slide

Radiation hazards &infection control in orthodontics / orthodontic courses by indian dental academy

  1. 1. www.indiandentalacademy.com INDIAN DENTAL ACADEMY Leader in continuing dental education www.indiandentalacademy.com
  2. 2. ContentsContents Introduction Radiation biology Radiation Chemistry Effects of Radiation Relevance of Radiation Exposure in orthodontics Radiation Protection Bibliography www.indiandentalacademy.com
  3. 3. Introduction X-rays are a form of electromagnetic radiation Ability to ionize matterwhich is the initiating event in radiation induced biologic changes www.indiandentalacademy.com
  4. 4. RADIATION BIOLOGYRADIATION BIOLOGY  IS THE STUDY OF THE EFFECTS OF IONIZING RADIATION ON THE LIVING SYSTEM.   Deterministic Stochastic Severity of response probability of a proportional to dose response occur www.indiandentalacademy.com
  5. 5. RADIATION CHEMISTRYRADIATION CHEMISTRY  Free radical production  RH + Photon R + H+ + e  These free radicals are unstable ,short lived and highly reactive.  Fate of the free radical _ 1) Dissociation R X + Y 2) Cross linking R + S RS www.indiandentalacademy.com
  6. 6. thus there is formation of structurally and functionally biologic molecules differing from original molecule.there by inducing biological change. www.indiandentalacademy.com
  7. 7.  Radiation acts on living system either DIRECT INDIRECT Direct ionization of biologic photon absorbed by H2O macromolecules with H2O IONIZED formation of unstable free radicals. Resultant free radical interact and change the macro moleculewww.indiandentalacademy.com
  8. 8. Radiosensitvity and cell typeRadiosensitvity and cell type  Most radiosensitive cells are are 1)undergoing mitoses 2)having a high mitotic rate 3)are most primitive in differentiation www.indiandentalacademy.com
  9. 9.  Cells are usually divided into five categories of radiosenstivity 1)vegetative inter mitotic cells 2)differentiating inter mitotic cells 3)multipotential connective tissue cells 4)reverting post mitotic cells 5)fixed post mitotic cells www.indiandentalacademy.com
  10. 10. )vegetative intermitotic cells—most radiosensitive Eg:precursor cell– spermatogenicerythoblastic ,basal cells of the oral mucous membrane. 2)differentiating intermitotic cells –Eg: intermediate cells of hemapoietic ,replicating cells of the inner enamel epithelium www.indiandentalacademy.com
  11. 11.  Multi potential connective tissue cells – ---Eg intermediate radio sensitivity --- : endothelial cells,fibroblasts  Reverting post mitotic cells ---radio resistant ---Eg: acinar and ductal cells of salivary gland and pancreas,parenchymal cells of liver ,kidney and thyroid  Fixed post mitotic cells---most radioresistant ---Eg:neurons ,striated muscle cells ,squamous cells close to the surface of oral mucous membrane and erythocytes www.indiandentalacademy.com
  12. 12. High Intermediate Low Lymphoid Fine vasculature Optic lens Bone marrow Growing cartilage Mature Growing bone eryhtocytes Intestines Salivary glands Muscle Mucous Lungs cells membrane Kidney Neurons Liver Relative Radio sensitivityRelative Radio sensitivity of Various Organsof Various Organs www.indiandentalacademy.com
  13. 13. www.indiandentalacademy.com
  14. 14. Radiation effects may be spoken In terms :- the short term effects which bring about … mitosis linked cell death the long term effects that bring about….fibro atrophic cell death www.indiandentalacademy.com
  15. 15. Short term effectsShort term effects  Primarily determined by the sensitivity of the parenchymal cells of the respective tissue  Raidly proliferatingcell loss mitosis linked reduction in the number of mature cells .  In tissues that undergo little proliferation the radiation induced hypoplasia is not evident www.indiandentalacademy.com
  16. 16. Long Term EffectsLong Term Effects Determined by the extent of damage to the fine vasculature of the tissue Endothelial cells---multi potential connective tissue cells---intermediate radio sensitivity.. Thus over a period of time ---capillaries ,degenerate and undergo necrosis. Permeability increased www.indiandentalacademy.com
  17. 17.  progressive fibrotic processes begins around the capillaries This fibrotic scar tissue will eventually cause obliteration of blood vessels--- depriving the cells of nutrition ,oxygen and elimination of waste Eventually leading to loss of cell function ,decreased resistance to infection and death of all cell types…with the net result of PROGESSIVE FIBROATROPHY www.indiandentalacademy.com
  18. 18. www.indiandentalacademy.com
  19. 19. Oral mucousOral mucous membranemembrane www.indiandentalacademy.com
  20. 20. • Oral mucous membrane * Short term effects –related to the radiosensitive vegetative intermitotic cells of the basal layer of the mucous membrane. * Initially —redness and inflammation—mucositis *as therapy continues – formation of whitish yellow pseudomembrane—desquamated epithelial layer *2 months after therapy—rapid healing--- • mucosa becomes atrophic,thin relatively avascular. www.indiandentalacademy.com
  21. 21. Taste budsTaste buds *are radiosensitive—extensive degeneration *loss of taste acuity during second or third week of radiotherapy *recovery usually takes between 60-120 days www.indiandentalacademy.com
  22. 22. Salivary glandsSalivary glands  The parenchymal component of salivary glands is radiosensitive  Short-term effects –inflammatory response  Long-term effect progressive fibrosis,adiposis,loss of fine vasculature with parenchymal degeneration---accounting for xerostomia.  Marked reduction of salivary flow is seen in the 1st two weeks  Xerostomia ,decreased ph of saliva (6.5to 5.5)--- this is low enough to cause decalcification  Buffering capacity falls by 44%www.indiandentalacademy.com
  23. 23. Flora thus becomes more acidogenic in saliva and plaque ---this along with thick viscous ,acidic saliva---renders patient susceptible to radiation caries. Oral micro flora changes –strept.mutants,lactobacillus and candidasis Recovery—6 to 12 months If not –unlikely that there will be significant recovery www.indiandentalacademy.com
  24. 24. www.indiandentalacademy.com
  25. 25. Radiation cariesRadiation caries Rampant form of decay  Irradiation of the teeth does not influence the decay but the changes induced in the salivary glands and saliva are responsible for this decay  There are three types of radiation caries -----superficial lesions—B,O,Li,P surfaces -----primarily involving cementum and dentin in the cervical region -----dark pigmentation of the entire crown www.indiandentalacademy.com
  26. 26. Reducing ----daily application for 5 minutes of a viscous topical 1% neutral NaF gel --------avoidance of dietary sucrose www.indiandentalacademy.com
  27. 27. TeethTeeth www.indiandentalacademy.com
  28. 28. TeethTeeth  Severity of damage is dose dependent  If irradiation precedes calcification –tooth bud destroyed  After calcification has begun—inhibition of cellular differentiation –malformations and arresting growth  Adult teeth are relatively radioresistant  Pulpal tissue –reverting and fixed postmitotic cells —may show long –term fibroatrophy  No discrenible effect on the crystalline structure of enamel ,dentin or cementumwww.indiandentalacademy.com
  29. 29. BoneBone Primary damage—results from damage to the vasculature of the periosteum and cortical bone Also the radiation tends to destroy osteoblasts and to a lesser extent osteoclasts Bone marrow fatty bone marrow and fibrous connective tissue  marrow  hypo vascular,hypoxic and hypo cellular Degree of mineralization reduced brittle www.indiandentalacademy.com
  30. 30. www.indiandentalacademy.com
  31. 31. OsteoradionecrosisOsteoradionecrosis Decreased vascularity -renders bone susceptible to infections Source of these infections may be from radiation –induced breakdown of the oral mucous membrane ,mechanical damage tooth extraction ,denture sore,PD lesion or radiation caries... Mandible > maxilla www.indiandentalacademy.com
  32. 32. Relevance of Radiation in Orthodontia www.indiandentalacademy.com
  33. 33. Relevance of Radiation inRelevance of Radiation in OrthodontiaOrthodontia • Most commonly taken radiographs in Orhtodontia are :-lateral cephalogram panoramic radiograph • hand- wrist x-rays • Exposure of critical organs which are:- active bone marrow thyroid gland salivary glands optic lenswww.indiandentalacademy.com
  34. 34.  Exposure is of low doses …example for the formation of cataract 2Sv(200 rem)but in opg dose exposed to in the form of scattered radiation is only 80 microSv  Also studies by Danforth and Gibbs  Thyroid160-370 microGys  Pitutary 70-490 microGys  Salivary glands 393 microGys  As these doses are well below the maximum permissible dose the harmful effects still remain uncertain www.indiandentalacademy.com
  35. 35. Harmful effects manifest as increased probability of a normally occurring disease Bear in mind ALARA principle www.indiandentalacademy.com
  36. 36. Maximum Permissible DoseMaximum Permissible Dose  Two categories :-ouupationally exposed  Non occupationally exposed Whole body Isolated areas of body Occ.exp. 0.05Svyear 0.75Svyear Non occ. 0.005Svyear 0.075Svyear Exp. www.indiandentalacademy.com
  37. 37. Radiation SafetyRadiation Safety Two aspects:- Patient Protection Protection of Personnel www.indiandentalacademy.com
  38. 38. Patient protection 1) Intensifying screens 2) Focal spot to film distance 3) Collimation 4) Filtration 5) Lead aprons and collars 6) Good radiographic techniques www.indiandentalacademy.com
  39. 39. Protection of PersonnelProtection of Personnel Barrier/position and distance rule Operator never hold film Personnel should wear film badges Regular checks of x-ray equipment for spills www.indiandentalacademy.com
  40. 40.  IS A COLLECTION OF SIGNS AND SYMPTOMS EXPERIENCED BY PERSONS AFTER ACUTE WHOLE BODY EXPOSURE TO RADIATION 1)Prodromal Period 2)Hematopoietic Syndrome 3)Gastrointestinal Syndrome 4)Cardiovascular Syndrome Acute Radiation SyndromeAcute Radiation Syndrome www.indiandentalacademy.com
  45. 45. GASTROINTESTINALGASTROINTESTINAL SYNDROMESYNDROME 7 to 15 Gy causes extensive damage to the rapidly proliferating epithelial cells of the intestinal villi with resultant –denudation of mucosal surface ,loss of plasma and electrolytes these changes are responsible for diarrhea,dehydration,and weight losses well as invasion of endogenous intestinal bacteria producing septicemia. www.indiandentalacademy.com
  46. 46. These damages along with the hematopoietic damage together contribute to the signs and symptoms of GASTROINTESTINAL SYNDROME www.indiandentalacademy.com
  47. 47. CARDIOVASCULAR AND CENTRALCARDIOVASCULAR AND CENTRAL NERVOUS SYSTEM SYNDROMENERVOUS SYSTEM SYNDROME Exposure to a dose in the range of 50Gy will cause death in a few minutes to 2 days There is collapse of the cardiovascular system and autopsies reveal necrosis of the cardiac muscle . Damage to the nervous system manifests as patient showing intermittent stupor ,inco- ordination,disorientation and convulsions www.indiandentalacademy.com
  48. 48. www.indiandentalacademy.com
  49. 49. ContentsContents  Introduction  Mechanisms of Cross Infection  Important Pathogens in Infection Control  Control of Cross-Infection  Sterilization in Orthodontics www.indiandentalacademy.com
  50. 50. Pathways for Cross-Contamination Patient to dental team Dental team to patient  Patient to patient  Dental office to community Modes of disease spread :-Direct contact Indirect contcat Droplet infection IntroductionIntroduction www.indiandentalacademy.com
  51. 51. Mechanism or site of entry into body:- through breaks in skinmucous membrane through inhalation www.indiandentalacademy.com
  52. 52. www.indiandentalacademy.com
  53. 53. There are several important disease in infection control but the ones of most significance in the dental office are:- Hepatitis B virus HIV Herpes Simplex Virus www.indiandentalacademy.com
  54. 54. Infectious agent Disease or condition Route of transmission Incubation period Communicable period Hepatitis A virus ‘Infectious hepatitis’ Type A Hepatitis Feco-oral, Food , water, shellfish 2 to 6 wks (av. 28 to 30 days) 2 to 3 wks before onset (jaundice) through 8 days after Hepatitis B Virus ‘Serum hepatitis’ Type B Hepatitis Blood, saliva, body fluids,sexual contact, perinatal 2 to 6 months ( av. 60 to 90 days ) Before, during & after clinical signs Carrier state: indefinite Delta Hepatitis Virus ( HDV ) Delta Hepatitis Coinfection with HBV, Blood, Sexual contacts, Perinatal 2 to 10 weeks All phases Non-A, Non-B Hepatitis Virus Non-A, non-B hepatitis Similar to HBV 2 to 6 months Like HBV Epidemic non-A non-B Feco-oral Contaminated water 15 to 64 days Not known. Maybe like HAV Human Immunodeficienc y Virus ( HIV ) Acqired Immunodeficiency Syndrome ( AIDS ) Blood & blood products ( infected i.v needles ), sexual contact, perinatal, 3 months to 5 years 2 years for transfusion case ) From asymptomatic through onset of opportunistic infections www.indiandentalacademy.com
  55. 55. Herpes Simplex Virus Type I ( HSV -1 ) Type II (HSV-2 ) Acute Herpetic gingivostomatitis Herpetic labialis Ocular herpetic infections Herpetic Whitlow Saliva, direct contact ( lip, hand ) Indirect contact (on objects, limited survival) Sexual contact 2 to 12 days Labialis: one day before onset until lesions are crusted Acute stomatitis: 7wks after recovery Asymptomatic infection: with viral shedding Reactivation period: with viral sheddingVaricella-zoster virus (VZV) Chickenpox Shingles Direct contact Indirect contact Airborne droplet 2 to 3 weeks 5 days prior to onset of rash until crusting of vesicles Epstein- Barr Virus ( EBV ) Infectious mononucleosis Direct contact Saliva 4 to 6 weeks Prolonged Pharyngeal excretion 1yr after infection Cytomegalovirus ( CMV ) Neonatal CMV infection CMV disease Perinatal Direct contact(most body secretions) Blood transfusion Inexact 3 to 8wks after transfusion Months to years www.indiandentalacademy.com
  56. 56. Treponema pallidum Syphilis Direct contact Transplacental 10 days to 10 weeks Variable and indefinite Maybe 2 to 4 years Neisseria gonorrhoea Gonorrhea Direct contact Indirect contact (short survival of organism) 2 to 9 days During incubation Continued for monthsand years if untreated Group A streptococci (Beta-hemolytic) Streptococcus pyogenes Streptococcal sore throat Scarlet fever Impetigo Erysipelas Respiratory droplets Direct contact 1 to 3 days 10to 21 days, untreated Many nasal oropharyngeal carriers Staphylococcus aureus Staphylococcus epidermidis Abscesses Boils (furuncles) Impetigo Bacterial pneumonia Saliva Exudates Nasal discharge 4 to 10 days Variable and indefinite While lesions drain and carrier state persists www.indiandentalacademy.com
  57. 57. Influenza viruses Influenza Nasal discharge Respiratory droplets 24 to 72 hrs 3 days from clinical onset Measles Virus (Morbilivirus) Rubeola (measles) Direct contact Saliva Airborne droplets 8 to 13 days to fever, 14 days to rash Few days before fever to 4 days after rash appears Rubella virus (Togavirus) Rubella (German measles) Nasopharyngeal secretions Dirrect contact Airborne droplets 16 to 23 days From 1wk to at least 4 days after rash appears Congenital Rubella Syndrome Maternal infection, first trimester Infants shed virus for months after birth Mumps virus (Paramyxovirus ) Infectious parotitis Direct contact (saliva) Airborne droplets 2 to 3 wks (average 18 days) From 1 to 7 days before sympoms until 9 days after swelling Polio virus types 1,2,3 Poliomyelitis Direct contact (saliva), Droplet, Feco-oral 7 to 14 days Probably most infectious 7 to 10 days before and after onset of symptoms Mycobacteriu m Tuberculosis Tuberculosis Droplet nuclei Sputum Upto 6 months Long, repeated exposure usually www.indiandentalacademy.com
  58. 58. www.indiandentalacademy.com
  59. 59.  An infection-control program comprises two distinct areas: exposure control and hazard communication.  Exposure control covers sterilization and disinfection, waste management, and employee including personal protective equipment and bodily-fluid-exposure protocols.  Hazard communication requirements include a periodic checklist for OSHA compliance, drills for hazard communication plans (chemical spills, emergency first aid, and fire or tornado evacuation), secondary labeling of hazardous chemicals, Material Safety Data Sheets, x-ray updates, and properly displayed state and federal posters.www.indiandentalacademy.com
  60. 60. TerminologiesTerminologies  Sterilization it is the process of destroying all forms of microbial life  Disinfection it is defined as the removal of or inactivation of microbes.thus it implies only some and not all pathogenic organisms can be eliminated by this method.  Anti-septicsthese are substances that prevent the growth or action of microbes by either destroying them or inhibiting their actions www.indiandentalacademy.com
  61. 61. Sanitizersreduce the microbial population to safe levels as judged by public health requirements.they are usually chemical agents that kill close to 99.9%of the organisms. Germicideskill the growing forms but not necessarily the resistant spores. Bacterio static agents agents which have the ability to inhibit he growth of bacteria. www.indiandentalacademy.com
  62. 62. SterilizationSterilization Is a process intended to kill all microorganisms whether vegetative or pathogenic . It is the highest level of microbial killing that can be achieved www.indiandentalacademy.com
  63. 63. The protocol for sterilization of instruments is usually 1)holdingpresoaking 2)pre cleaning 3)sterilization process 4)aseptic storage and handling of instruments www.indiandentalacademy.com
  64. 64. Holding PresoakingHolding Presoaking If instrument not to be cleaned immediately soak in holding solution prevents salivablood from drying up. Holding solution usually is a germicidal Discard solution at least once a day Avoid prolonged soakingcorrosion www.indiandentalacademy.com
  65. 65. Pre cleaningPre cleaning Reduces amount of microbes present ,but more importantly removes blood saliva and other materials that may insulate microbes from the sterilizing agent. May be achieved by ultrasonic manual www.indiandentalacademy.com
  66. 66. Sterilization ProcessSterilization Process A) Physical agents B) Sunlight C) Dry heat:- flaming incineration hot air D) Moist heat :  boiling steam under pressure E) Filtration:- membranes asbestos padswww.indiandentalacademy.com
  67. 67. F) Ultraviolet light G)Radiation H)Micro-wave I)Lasers www.indiandentalacademy.com
  68. 68. In dentistry the procedures used are:- 1)Heat sterilization 2)Gaseous sterilization 3) Liquid chemicals sterilization www.indiandentalacademy.com
  69. 69. Heat sterilizationHeat sterilization a) Moist heat:-steam pressure autoclave b) Unsaturated chemical vapour:- chemiclave c) Dry heat:- conventional dry heat ovens :- short cycle high temperature dry heat ovens www.indiandentalacademy.com
  70. 70. Steam Pressure AutoclaveSteam Pressure Autoclave  Sterilizes by bringing about oxidation as well as denaturing proteins  It is the latent heat and not the pressure built inside by steam within the closed chamber that is responsible for killing of the microbes  Two cyclesStandard..20 –30 mins.at 250°f Flash cycles..3-10 mins.at 273°f www.indiandentalacademy.com
  71. 71. Advantages time efficient,good penetration Disadvantages 1)may lead to corrosion of susceptible instruments. 2)items sensitive to elevated temperatures get damaged www.indiandentalacademy.com
  72. 72. Unsaturated Chemical vaporUnsaturated Chemical vapor Chemical solution heated in a closed solution-chemical vapor kills the microbes 0.23%formaldehyde,72.38%ethanol along with acetone,ketone and water 20 min at 270°f www.indiandentalacademy.com
  73. 73. Advantages 1)eliminates or reduces the corrosion of susceptible instruments. 2)dry instruments available at end of cycle Disadvantages 1)items sensitive to elevated temp.will get damaged 2)pre drying of inst.a must www.indiandentalacademy.com
  74. 74. ChemiclavveChemiclavve www.indiandentalacademy.com
  75. 75. Dry HeatDry Heat  Conventional dry heat ovens *heat chambers wherein heated air is circulated by gravity convection *320f for 30 min *place packs at least 1 cm apart to allow for the hot air to circulate between wrapped instruments www.indiandentalacademy.com
  76. 76. www.indiandentalacademy.com
  77. 77. Short –cycle high temperature dry heat ovens Are force draft ovens 370°f to 375°f for 6 to 12 mins Advantages :-1)instruments sensitive to corrosion may be safely sterilized 2)effective rapid cycles are possible 3)items dry at end of cycle www.indiandentalacademy.com
  78. 78. Disadvantage Instruments sensitive to elevated temp. will get damaged Ethylene oxide sterilization  for complex, delicate , heat sensitive inst. aeration of about 24hours must pror to use of instruments especially porous and plastic ones www.indiandentalacademy.com
  79. 79. Dry heat sterilizerDry heat sterilizer www.indiandentalacademy.com
  80. 80. Boiling waterBoiling water Even though seen to be used commonly it does not kill spores and does not bring about sterilization of instruments Heat reaches and kills the blood borne pathogens 100° for 10 min. Thus more than sterilization it is a process of high level disinfections www.indiandentalacademy.com
  81. 81. www.indiandentalacademy.com
  82. 82. www.indiandentalacademy.com
  83. 83. Chemical MethodsChemical Methods Chemical agents are used for controlling of microbes on body surfaces and on inanimate objects are grouped under disinfectants These includeantiseptics sanitizing degerming disinfecting agents www.indiandentalacademy.com
  84. 84. Qualities of a universalQualities of a universal disinfectantdisinfectant 1)destroy all forms of microorganisms within a practical period of time 2)non-toxic,non-allergic,non-irritating 3)non-corrosive,non-discolouring ,non- degrading 4)good wettability and penetrabilityfor effective contact even in the presence of blood and exudate 5)readily soluble in available solvents www.indiandentalacademy.com
  85. 85. ClassificationClassification  Spaulding in 1972 A. High level disinfectants Eg:-ethylene oxide gas,immersion glutheraldehyde solutions B. Intermediate level disinfectants Eg:-formaldehyde ,chlorine compounds,alochol,iodophors ad phenolic compounds www.indiandentalacademy.com
  86. 86. C.Low level disinf. Narrowest anti-microbial activity Eg:- quaternary ammonium comps www.indiandentalacademy.com
  87. 87. Categories of chemicalCategories of chemical disinf.disinf.  A) Alcohols  B) Aldehydes  C) Halogens  D) Surfactants  E) Quanternary ammonium compounds  F) Phenols and Phenolic compoundwww.indiandentalacademy.com
  88. 88. A. Alcohols bactericidal and fungicidal but not sporicidal MOA :- denature proteins solvent action on lipids Ethyl and isopropyl alcohols…most commonly used optimum conc. 70% range 60-95% If conc.falls below 45%antmicrobial activity is slow and uncertain www.indiandentalacademy.com
  89. 89. Alkalating agents Formaldehyde Gaseous state …used as a fumigant MOA :- protoplasmic poison denaturing proteins  Disadvantage:-pungent odour ,irritating t skin ,poor penetrating and slow acting www.indiandentalacademy.com
  90. 90. Gluteraldehyde :- less pungent volatile and irritating with better disinfectant properties broad spectrum of activity2%sol.bactericidal,tubercu locidal and virucidal in 10 mins and sporicidal in 10 hours gluteraldehyde+iodine comp.+bleach recommended for use against Hb virus where sterilization not feasible www.indiandentalacademy.com
  91. 91. They also have a low surface tension and can thus penetrate blood and exudate thus reaching instruments surfaces Also used for disinfection of impressions Cidex , sporicidin, glutorex www.indiandentalacademy.com
  92. 92. www.indiandentalacademy.com
  93. 93. HalogensHalogens Iodine Iodophors Chlorine www.indiandentalacademy.com
  94. 94. Chlorine Sanitizing agent Elemental chlorine used for water purification may also be used as a surface disinfectant conc. 2.5% gloves must be worn corrosive to metals www.indiandentalacademy.com
  95. 95. Iodine :- used for wound and skin antisepsis Tinctures of iodine are usually used in 1,5and 7% conc. Which destroy 90%of bacteria in 90,60 and 15 sec. respectively • Iodophors:- composed of complexes of iodine and surface active organic carrier molecules from which iodine gradually released . www.indiandentalacademy.com
  96. 96. SurfactantsSurfactants Soaps :- degerm the skin by mecanical removal of microbes bacterostatic and bacteriocidial www.indiandentalacademy.com
  97. 97. Phenols :- As disinfectants and antiseptics MOA:-denaturing of proteins or damage to cell membrane Bacteroicidal and bacteriostatic…but poor viricidal properties www.indiandentalacademy.com
  98. 98. www.indiandentalacademy.com
  99. 99.  These include :-  Gloves  Mouth masks  Protective eyewear  Hand washing  Immunization www.indiandentalacademy.com
  100. 100. GlovesGloves The need for gloving The practices of gloving not only provides protection to dentist but also to the patient www.indiandentalacademy.com
  101. 101. For eg:- Dentist dentist contracts treats herpes…herpes whitlox patient with herpes simplex to patients treated in future www.indiandentalacademy.com
  102. 102. Patient Care GlovesPatient Care Gloves Disposable gloves Do not wash gloves with detergents in an attempt to reuse While leaving chairside remove gloves While working chair side try and put to use the practice of double gloving www.indiandentalacademy.com
  103. 103. www.indiandentalacademy.com
  104. 104. Protective EyewearProtective Eyewear  Protection from microbes  Eg:HSV, Hepatitis B  Protection against physical damage  Protection from impact damage  Protection from splashes of chemicals www.indiandentalacademy.com
  105. 105. Preferable to use goggles over glasses as former not only provides protection from front splash and impacts but also from side impacts and splashes www.indiandentalacademy.com
  106. 106. Hand washingHand washing Two types of micro flora  resident flora transient flora www.indiandentalacademy.com
  107. 107. Resident flora:colonize and become resident can never be completely eliminated less imp. In causing disease www.indiandentalacademy.com
  108. 108. Transient flora:acquired whilst dealing with contaminated objectssurfaces do not colonize or survive for long periods on the hand usually pathogenic can be removed by following a good hand washing protocol www.indiandentalacademy.com
  109. 109. Hand washing products containing low levels of microbial agents used in a 10 –30 sec.hand wash routine minimizes the no.of transient flora and aids in reducing the no.of resident flora too. Chlorhexidine digluconate ,povidine iodine,parachlorometaxylonol Washing of hands before and after gloving very imp. www.indiandentalacademy.com
  110. 110. Commonly used HandCommonly used Hand DisinfectantsDisinfectants www.indiandentalacademy.com
  111. 111. MasksMasks Protect mucous membrane of mouth and nose from contact with aerosolssprayssplashes of oral fluids from patients…also in turn protect patient Composed of material that filters out 95%- 99.9%of 2-3 micrometer size particles that directly contact it They should be form-fitting over the bridge of the nose to reduce fogging of eyewear www.indiandentalacademy.com
  112. 112. Dispose mask once it gets moist resistance to airflow through the mask increasesmore unfiltered air is allowed to pass by the edge of the mask Use disposable maskschanging between patients www.indiandentalacademy.com
  113. 113. ImmunizationImmunization Hepatitis The HBV is an infectious agent associated with acute and chronic hepatitis . Major cause of necrotizing vasclitis,cirrhosis , and primary hepatocellular carcinoma. Found primarily in blood and blood products …may also be present in other body fluids…saliva , semen,tears,urine www.indiandentalacademy.com
  114. 114. Transmitted parenterally,sexual contact,mother to fetus HBV relatively environmentally stable… potential for indirect transmission via contact with contaminated inst. Best protection is by immunization Two vaccines Recombivax HB and EngerixB Regime :-1.0ml doses given at 0, 1, and 6 mths www.indiandentalacademy.com
  115. 115. Following vaccination protective levels of antibodies are believed to persist for seven years Need for booster dose is being debated www.indiandentalacademy.com
  116. 116. Sterilization of OrthodonticSterilization of Orthodontic PliersPliers  autoclave or chemiclave . The only major obstacle of pliers sterilization is related to their corrosion suceptibility. www.indiandentalacademy.com
  117. 117.  corrosion resistance of orthodontic grade steel is directly proportional to its chromium content and inversely proportional to its carbon content . disruption of chromium oxide layer renders them suceptible to corrosion. Instruments made of carbon or 400 series steel are more susceptible than those made of 300 series steel. www.indiandentalacademy.com
  118. 118. Steps to prevent corrosionSteps to prevent corrosion  first be cleaned thoroughly and rinsed with distilled water .  do not allow contaminants to dry Tap water to be avoided– use only distilled water www.indiandentalacademy.com
  119. 119. Chrome-plated instruments should be autoclaved separately from stainless steel ones.  Detergents with chloride bases should not be used , Purple or black staining is caused by exposure to ammonia. * www.indiandentalacademy.com
  120. 120. ArchwiresArchwires Contaminated archwires are sterilized in divided plastic containers Cut to appropriate length and kept overnight in gluteraldehyde solution Thereafter stored in binsuntil ready to be used www.indiandentalacademy.com
  121. 121. Recycling of archwires the relative high costs of archwires has lead to one trying out the practice pf reclcycling of arch wires Both cold and heat sterilization have been tried Heating cycle should not exceed 235 C for a total of 20 minsto keep impact on wires properties to the minimum. www.indiandentalacademy.com
  122. 122. Studies on Recycling ofStudies on Recycling of Orthodontic Arch wiresOrthodontic Arch wires www.indiandentalacademy.com
  123. 123. Mayshew ,Kusy Am.j.OrthoMayshew ,Kusy Am.j.Ortho 19881988  Effect of sterilization on mechanical properties and surface topography of 0.017” x 0.025” NiTinol and Titanal wires  Three methods:- dry heat at 180 c for 60 min formaldehyde alcohol vapour ,132c for 30 min steam autoclave ,121 c for 20 min at 15-20 psi www.indiandentalacademy.com
  124. 124. Tests conducted:- Three point bending—elastic moduli Surface topography –laser scattering Tensile properties—instron utm Results:- No significant change in tensile properties with any sterilization procedure No change in elastic moduli No apparent effect on surface topography www.indiandentalacademy.com
  125. 125. Buckthal, Kusy :Am.J.Ortho .Buckthal, Kusy :Am.J.Ortho . 19981998  Effects of cold disinfectabnts on mechanical properties and surface topography of 0.017” x 0.025” NiTinol and Titanal wires  Three disinfectants tested:- 2%acidic phetaraldehyde for 10 hours  Cholorine dioxide for 6 hours  Iodophor for 10 hours ..mixture at the ratio of 1/256 with water. www.indiandentalacademy.com
  126. 126. Tests :- Bending ,tensile,laser spectroscopy Results :- No change in elastic moduli No change in surface topography No change in tensile properties www.indiandentalacademy.com
  127. 127. Laboratory AsepsisLaboratory Asepsis  Counter tops:-wipe counter tops with effective disinfectants.  Impressions:- easily contaminated with blood and saliva microorganisms easily transferred from contaminated impressions to casts where they can remain viable for upto 7 days…thus providing a path for cross contamination from the clinic to the laboratory personnel www.indiandentalacademy.com
  128. 128.  Impressions after being removed from the mouth should be rinsed under running water …this enables the removal of adhering microorganisms  They are then placed into plastic bags with appropriate disinfectants for approximately 15 mins…followed by their removal and rinsing of the disinfectant…they are now ready to be poured  If the impression is sensitive to immersion an alternate would be to spray the impression with the appropriate disinfectant and wrap it with a paper towel moistened with the same disinfectant for 15 mins. www.indiandentalacademy.com
  129. 129. BibliographyBibliography White and Pharoah: Oral Radiology:Principles and Interpretations Robert langleins,Olaf e.langland,McDavid:Panoramic Radiogaph Casebow, M.P.:patient doses from Orthopantomograph x-ray exposures,Br. J. Radiol.,46:230,1973 www.indiandentalacademy.com
  130. 130. Chris H. Miller and Charles J. Palenik:Infection Control and management of Hazardous Materials for the Dental Team Mayshew,Kusy:Recycling of orthodontic wires:Am. J. Ortho 1988 Buckthal,Kusy: Am. J. Ortho.1998 www.indiandentalacademy.com
  131. 131. www.indiandentalacademy.com For more details please visit www.indiandentalacademy.com