sterilisation in orthodontics


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sterilisation and disinfection in orthodontics

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  • P-DDirect contact (touching) with patient's saliva or blood may lead to entrance of microbes through a nonintact skinSprays, spatter, or aerosols from the patient's mouth may lead to droplet infectionIndirect contact -contact with the contaminated item or surface.D-PIf the hands contain lesions or non intact skin,Direct contact with the patient's mouth, microbes may gain entrance through mucous membranes or open tissue.P-Pindirect contact through improperly prepared instruments,handpieces and attachments, operatory surfaces, and hands
  • Third level which is the most important level is with which we are going to deal with i.esterilisation
  • Chemical claving longer time is requierd and effectiveness is questionable thus it may be secondary option
  • Finding suggest changes in the peoperties can be seen but were not significant that is strecthing required to deliver 500 gm force was increased by 5 mm and force required to break the chain was decreased by 10-20 % onlyDiscoloration also was seenThus concluded that cold sterilisation had no effect on properties of e chain and can be convenient approach for sterilisation
  • vital defense - 9% o-phenylphenol and 1% o-benzyl-p-chlorophenolCidex plus- 3.4%glutaraldehyde solution.
  • studies were conducted to analyse the effects of these sterilisation methods on the mechanical properties and surface topographic changes in arch wires.
  • Thus suggesting the use of cold disinfectsnts as part of sterilisation purposes if desired to reuse the wire.
  • 1 ss wire- truchrome2 niti wires neosentalloy3 tma wires-resolveDid not provide any significant changes in the properties of the wires and few minimal changes observed were insignificant for every day clinical use.Three point bending test showed no change in the behaviourupto 3 mm
  • 1 cycle here means 8 wks plus or minus 1 wk
  • Fracture toughness was tested by placing the implant in 4mm thick cortical femur bone of pig using digital torque machine.
  • Medical history reveals carrier nature from mother to offspringBarrier techniques include gloves,mask,eyewear
  • sterilisation in orthodontics

    1. 1. Sterilisation And Disinfection In Orthodontics Dr.Sandeep Postgraduate SVS Institute Of Dental Sciences 8/25/2013 1
    2. 2. contents • Introduction • Definitions • Pathways of transfer of infection • Classification • Sterilisation methods basics • Sterilisation of orthodontic armamentarium – Pliers – Brackets – Molars bands – Arch wires – Pencils – TADS • Hepatitis B • Conclusion 8/25/2013 2
    3. 3. Introduction • Microorganisms are ubiquitous • Pathogenic microbes may be transmitted directly from the dentist to the patient or from the patient to the doctor, and indirectly from patient to patient. • Thus ,it is necessary to remove them as they cause contamination , infection and decay. • This presents an enormous challenge in the current scenario as it has been proved that blood and saliva are high risk sources of contracting hepatitis b, human immunodeficiency virus and herpes. 8/25/2013 3
    4. 4. How ?By What ? Infection control 8/25/2013 4
    5. 5. 8/25/2013 5 • Sterilization is defined as the process by which an article, surface or medium is freed by all living micro- organisms either in vegetative or spore state. • Disinfection- means the destruction or removal of all pathogenic organisms or organisms capable of giving rise to infection. • Antisepsis- used to indicate the prevention of infection, usually by inhibiting the growth of bacteria in wounds or tissues. • Antiseptics- Chemical disinfectants which can be safely applied to skin or mucous membrane and are used to prevent infection by inhibiting the growth of bacteria.
    6. 6. • Bactericidal/germicidal- are those which are able to kill bacteria. • Bacteriostatic- are agents only that prevent the multiplication of bacteria which may however remain alive. • Decontamination- refers to the process of rending an article or area free of danger from contaminants including microbial, chemical, radioactive and other hazards. • Fumigation- exposure of an area or object to disinfectant, insecticidal or vermin killing fumes. 8/25/2013 6 Text Book of Microbiology- Ananthnarayan,8th edition
    7. 7. 8/25/2013 7
    8. 8. 8/25/2013 8 Spaulding's Classification first level – sanitization (thorough physical Cleaning). second level – disinfection ( kills microorganisms only) third level – sterilization ( kills all microorganisms & all spores) Text book of Infection Control and occupational safety recommendations for oral health professionalS
    9. 9. CDC classification Critical instruments: those used to penetrate soft tissue or bone, or enter into or contact the bloodstream or other normally sterile tissue. • eg: scalpels,forceps. Semi critical instruments: those that do not penetrate soft tissues or bone but contact mucous membranes or non-intact skin. • e.g: mirrors, reusable impression trays and amalgam condensers Non critical instruments: those that come into contact only with intact skin. • e.g: external components of x-ray heads, blood pressure cuffs and pulse oximeters. 8/25/2013 9Centers for Disease Control and Prevention. Guidelines for infection control in dental health care settings—2003. MMWR 2003; 50(No. RR-17).
    10. 10. 8/25/2013 10 Sterilisation
    11. 11. Sterilising methods PHYSICAL Sunlight Drying Heat Filtration Radiation Ultrasonic and sonic vibration CHEMICAL Alcohols Aldehydes Dyes Halogens Phenols Surface active agents Metallic salts Gases 8/25/2013 11
    12. 12. method Red heat Flaming Incineration Hot air oven Temp/techniq ue Till red hot Just pass over flame Burnt to ashes 160 deg Time/duratio n One hour materials Loops,tips of forceps Glass slides scalpels Soiled dressing Pathological waste Scalpels Scissors Forceps etc Dry Heat 8/25/2013 12
    13. 13. Moist Heat At temp Below 100 At temp of 100 At temp Above 100 Pasteurisation Inspissation Vaccine bath Boiling Tyndallisation Steam steriliser Autoclave 60 – 75 deg 100deg Temperature-1210C (2500F) Pressure -15 psi Pasteurisation - 30 min Inspissation – 30 min Vaccine bath – 60 min Boiling -10-30 min Tyndallisation – 20 min Steam steriliser – 90 min 15 – 20 mins 8/25/2013 13
    14. 14. Other physical Filtration Earthen ware Asbestos filters Sintered glass Membrane filters Radiation Ionising Non ionising 8/25/2013 14
    15. 15. Guidelines For Orthodontic Armamentarium Sterilisation • Minimal requirement for sterilising the orthodontic instruments are : – Ultrasonic – Dry heat steriliser – Autoclave • Other than this chemical sterilisation with alcohol and other vapours can be done for the instruments which are not in direct contact with blood or saliva. 8/25/2013 15
    16. 16. Orthodontic pliers 8/25/2013 16
    17. 17. 8/25/2013 17
    18. 18. Dry Heat Vs Moist Heat 50 ligature wire cutters Group 1 25 Autoclave 0.025 mm wire 50 cuts 6/12 cycles Group 2 25 Dry heat 0.025 mm wire 50 cuts 6/12 cycles 8/25/2013 18Effect of steam versus dry-heat sterilization on the wear of orthodontic ligature-cutting pliers; Ricardo J. Vendrel et al; AJODO 2002;121:467-71 • Ultrasonic cycle for 5-10 min • Rinsing with distilled water • Drying with compressed air • Lubrication with silicone based lubricants • Dry heat sterilisation at 190 deg for 6-12 min • Pliers should be open
    19. 19. Orthodontic brackets • Made from stainless steel • featuring a low profile catch that will not tear sterilisation wrap. • Suitable for all types of sterilisation. • Compartments are permanently marked for tooth identification. • Bracket Tray marked for 6 - 1 | 1 – 6,6 - 1 | 1 – 6 • Band Tray marked for 1st and 2nd Molars and 1st and 2nd Bicuspids. • Sold individually. 8/25/2013 19
    20. 20. Molar bands • Most overlooked materials in orthodontics. • Sterilisation of tried in preformed bands has received attention nowadays. • In orthodontic clinical practice the attachments on posterior teeth are commonly welded to stainless steel bands and cemented into position within the mouth. • Unlike directly bonded attachments, where one size fits all, bands have to be selected according to the size of the tooth to which they are to be cemented.8/25/2013 20
    21. 21. • During appliance placement several bands may be tried in the mouth before the appropriate size is selected. 8/25/2013 21 Sterilisation of bands autoclave Dry heat Glass bead
    22. 22. Autoclave 200 molar bands u/l Tried in patients Disinfecttion by enzymatic action Autoclave 134deg 3 min Inoculate in BHI medium 8/25/2013 22 M. R. Fulford et al Decontamination of tried-in orthodontic molar bands : European
    23. 23. Dry heat 8/25/2013 23 Ultrasonic cycle for 5 min Rinsing with distilled water Drying with compressed air Dry heat sterilisation at 190 deg for 6 min
    24. 24. Glass bead • Smith reported that glass bead steriliser can be used effectively to sterilise the tried in bands. • He recommended : – Single band for 1 min in bead steriliser due to fluctuations in temperatures other wise 45 sec is enough. – Temp : 225 – 250 deg. – 5 or more bands need to double the time. – Steriliser with deep and narrow wells are preferred over shallow ones as 8/25/2013 24 SMITH.G; GLASS BEAD STERILISATION OF BANDS; AJODO September 1986
    25. 25. Elastomeric ligatures and chains • These are not chemiclaved as they are known to alter the physical properties • Alcohol wipes are also not recommended as they are not so effective in blood and saliva • Single patient packs are best suitable for preventing cross contamination • Otherwise,in case of e chain spools it is better to cut little extra than required and discard rest 8/25/2013 25
    26. 26. E chains in 2% glutaraldehyde control 30 min 10 hrs Five cycle 30 min 144h/ 6 days Tensile strength Failure loading 8/25/2013 26Jeffries et al;Effects of 2% alakline glutaraldehyde on e- chains;Angle ortho ;1990;61(1),25-30
    27. 27. Vital defense E chains 10 min 1 hr 8hrs 48 hrs 7 days 14 days 28 days Tensile loading Cidex plus 8/25/2013 27Maylani B. Evangelista et al;Effect of Disinfecting Solutions on the Mechanical Properties of Orthodontic Elastomeric Ligatures:Angle Ortho, 77, (4), 2007
    28. 28. Arch wires • Arch wire sterilisation can ve done by routine 3 methods: – Cold sterilisation – Dry heat sterilisation – Autoclaving 8/25/2013 28
    29. 29. After the disinfection period wires were subjected to tensile bending ,and laser tests . Results show no significant changes in fundamental stiffness/strength of wires after disinfection NiTi wires 2% acidic glutaraldehyde 10 hrs Chlorine dioxide 6 hrs iodophors 10hrs 8/25/2013 29 Effects of Cold disinfectants on the mechanical properties and surface topograph of niti
    30. 30. 6 orthodontic wires autoclaving SEM study 3 point bending test 18 min 134 deg Optical microscopy 8/25/2013 30Influence of autoclave on the surface parameters and mechanical properties of 6 orthodontic wires;EJO:2005;27(1);72-81
    31. 31. • Ten NiTi wires were used in the study per each group. • Group 1 clinical recycling and dry heat sterilisation • Group 2 only DHS • Clinical recycling was done after 1 cycle. • Results: – showed that force levels increased after CR for NiTi wires between pre tx and first cycle. – Thus suggesting that CR appears to reduce pseudoplasticity and pseudoelasticity of NiTi wires increasing their stiffness. 8/25/2013 31Sunil Kapila, et al ;Load-deflection characteristics of nickel-titaniu alloy wires after clinical recycling and dry heat sterilization;AJODO;1992;102:120-6.
    32. 32. • a study was conducted in which CR then sterilised and as received wires of different types SS,NiTi,TMA wires were analysed for change in the properties. • Different test like:tensile loading,3 point bending test,laser topographic study were performed. • Load/deflection and tensile tests showed no clinically significant difference between as-received and used- then-disinfected/sterilized wires. • These results suggest that nickel-titanium arch wires can be recycled at least once. 8/25/2013 32 The effect of clinical use and sterilisation of selected orthodontic archwires :AJODO;1992;102:1539
    33. 33. Marking pencil • Marking pencils can be potential source of cross contamination. • Sterilisation options for these pencils are – EO gas – Alcohol wipes • These pencils cannot be autoclaved. • Use of permanent marking pens can also be considered for marking arch wires. • But these pens cannot be autoclaved as it is made of plastic. • cannot be cold sterilised as it contains ink. 8/25/2013 33 Disinfection of permanent markers;JCO;1996:30(1) ;646-649
    34. 34. • Probable solution may be use of ink containing alcohols. • Alcohols are considered as intermediate level disinfectants. • Study was conducted using red,blue,black permanent markers with alcohol . • Alcohol content ranging from 50-80%. 8/25/2013 34 Marking pencils as potential source of cross contaminaton;JCO;1998:32(5)
    35. 35. • Results suggest that alcohol are not so efficient in preventing cross contamination.but drying period of 10 min between 2 patients showed a decrease in bactrial count. • This suggests that pens after use should be left capped for 10 min to dry. • Finally,the best method to prevent cross contamination is use of inexpensive marking pencils which are disposable. 8/25/2013 35
    36. 36. TADS • Acc to CDC,placement of TADS is a surgical procedure and nedd high level of sterilisation. • Following are the requirements for procedure: – Surgical hand antiseptic – Surgical gloves – Irrigant devices – Sterile instruments – Sterile implant 8/25/2013 36
    37. 37. • Sterilisation of mini implants can be done by – autoclaving – Dry heat sterilisation • Dry heat strilisation should be done with caution as the implant cannot tolerate high temp. • And should be done with an temp indicators to identify when the ideal temp has reached for sterilsation. 8/25/2013 37
    38. 38. 100 mini implants 50 control 50 test group Autoclaved at 121 deg for 30 min Fracture toughness test 8/25/2013 38
    39. 39. • The results of this study suggest that mini-implants can be safely sterilized, with the method used in this study. • This will lead to no clinically significant changes to their resistance to fracture. Claudia et al; Effect of autoclaving on the fracture torque ofmini-implants used for orthodontic anchorage:Journal of Orthodontics, Vol. 38, 2011, 15–20 39
    40. 40. Torque readings and lateral dispalcement values were recorded 30 mini implants control 1 cycle Autoclave 132 deg for 6 min Test group 5 and 10 cycles 8/25/2013 40
    41. 41. • Repeated cycles of sterilization altered the surface characteristics of the mini-screws, as evidenced by the significant changes in their maximum insertion torque. • sterilization cycle as a main effect did not significantly affect lateral displacement force values. • study did not indicate major structural damage to the mini-screws that may affect their clinical stability and consistency as they are sterilized up to 10 cycles. 8/25/2013 41Sercan Akyalcin et al; Effects of repeated sterilization cycles on primary stability of orthodontic mini- screws;Angle Orthod. 2013;83:674–679.
    42. 42. Hepatitis B • The most common inflammatory disease of the liver is due to hepatitis B (HBV). • HBV is 50 to 100 times more infectious than HIV and is a major occupational risk for physicians, surgeons . • according to the studies conducted orthodontist exhibits the second highest incidence of HBV. 8/25/2013 42 JIOS;hepatitis b facts and concerns to orthodontist in india
    43. 43. Preventive measures Vaccination of doctor and assistant Medical history taking Barrier techniques Sterilisation • 8/25/2013 43
    44. 44. Hepatitis-B vaccination • Three doses are generally required to complete the hepatitis B vaccine series, although there is an accelerated two-dose series for adolescents. – First Injection - At any given time – Second Injection - At least one month after the first dose – Third Injection - Six months after the first dose – Booster dose – every five years 8/25/2013 44
    45. 45. Do hepatitis b patients are contraindicated for orthodontic treatment? • NO, • proper barriers techniques and sterilisation procedures before and after treatment should be followed to prevent cross infection. • And as they are not prescribed any systemic drugs there seems no contraindications. 8/25/2013 45
    46. 46. Dental impressions • Common disinfecting solutions used for impressions are – 1% naocl – Sodium dichlolroisocyanurate – 2% glutaraldehyde • Rinse the impression under running water • Immerse in disinfectant for 10 min • Rinse under water • Ready for model processing • In case of hepatitis b infected patients casts should be poured with gypsum containing 0.25% chloramines. 8/25/2013 46
    47. 47. conclusion • ―Prevention is better than cure‖ a proverb well suited to sterilization. • Thorough understanding of the application of sterilization will help ensure safety from the invisible but deadly world of microbial pathogens. • Hence utilization of proper sterilization, disinfectants and aseptic procedures help us achieve the safety of our professional demands. 8/25/2013 47
    48. 48. • All the above discussed sterilisation and disinfection methods and the studies conducted to evaluate their effects on mechanical and physical properties conclude that none of the properties are effected. • Thus sterilisation guidelines should be maintained to protect – Ourselves – Patients – Family and friends from cross infections. 8/25/2013 48
    49. 49. 8/25/2013 49 Thank