10

1
10

• Microbiology

2
Important People in Microbiology

• Anton Van Leeuwenhoek
• Magnifying glass
• Saw microorganisms from teeth for the first time
• Ferdinand Julius Cohn
• Classified bacteria as plants
• Divided bacteria into four groups

3
Important People in Microbiology

• Louis Pasteur
• Process of fermentation
• Proved bacteria causes disease

4
Important People in Microbiology

• Robert Koch
• Koch postulated that organisms must be
• Present in all cases of the disease
• Isolated in pure culture
• Capable of producing the disease in another
  person or animal
• Recovered again in pure culture

5
Important People in Microbiology

• Richard Julius Petri
• Petri dish
• Further developed technique for dispensing the
  bacteria onto the medium

6
Groups of Microorganisms

• Bacteria and virus groups
• Gram stain used to differentiate
• Gram positive if they keep their dark purple
  color
• Gram negative if they lose the color

7
Bacteria

• Need for oxygen
• Aerobic bacteria must have oxygen to grow and
  live
• Anaerobic bacteria are destroyed in the presence
  of oxygen
• Facultative anaerobic bacteria grow with or
  without oxygen present

8
Diseases Caused by Bacteria

• Tuberculosis
• Bacteria found in lungs
• Fatigue, fever, weight loss, persistent cough
• Airborne
• Dental personnel must wear masks
• Detected by a skin test and/or chest x-ray
• Treatment is antibiotics or other drugs

9
Diseases Caused by Bacteria

• Diphtheria
• Severe throat infection and fever
• Pertussis
• Respiratory disease
• Mainly affects infants and young children
• Tetanus
• Stiffness of the jaw (lockjaw)

10
Diseases Caused by Bacteria

• Strep throat
• Very common
• Sore throat, fever, general malaise
• Streptococcus mutans
• Species of the same bacteria
• Implicated in dental caries and endocarditis

11
Diseases Caused by Bacteria

• Staphylococcal infections
• Bacteria groups grow in clusters
• Antibiotics are the first line of treatments

12
Diseases Caused by Bacteria

• Anthrax
• Humans can get disease through cuts in skin or
  eating diseased meat
• Powder form
• Symptoms within 1 to 6 days
• Fever, weakness, dry hacking cough
• Prevention by vaccination or antibiotic treatment
  before symptoms

13
Diseases Caused by Bacteria

• Chlamydiae
• Microorganisms somewhere between bacteria and
  viruses (small in size)
• Genital, eye, and lymph node infections
• Most common sexually transmitted disease in the
  United States
• Antibiotics used as treatment

14
Protozoa

• Just below visibility of the naked eye
• Always dividing and changing shape
• Flagella
• Many have this long, threadlike appendage

15
Diseases Caused by Protozoa

• Amebic dysentery
• Severe diarrhea
• Abscesses may develop in liver
• Prevalent in countries where drinking water is
  contaminated and poor hygiene conditions prevail

16
Diseases Caused by Protozoa

• Periodontal disease (protozoa and bacteria)
• Both found in inflamed tissue around the tooth
• Protozoa is found in the plaque in the
  periodontal pockets around the tooth
• Treatments include removal, cleaning of plaque
  and tissue, and oral hygiene maintenance

17
Diseases Caused by Protozoa

• Malaria
• Symptoms during the first two weeks
• Fever and soreness at point of entry

18
Rickettsiae

• Parasites cannot live outside a host
• Lice, fleas, ticks, and mites transmit disease to
  humans

19
Diseases Caused by Rickettsiae

• Head lice
• Common among children in schools
• Transmitted easily through direct contact
• Eggs reproduce in hair shafts
• Treatment
• Medicated shampoo and cleaning bedding, brushes,
  and clothing with very hot water

20
Diseases Caused by Rickettsiae

• Rocky Mountain Spotted Fever
• Rare, curable
• Small pink dots appear
• Typhus
• Rare, treatable
• Severe headache, back and limb pain,
  constipation, rash, and confusion

21
Yeasts and Molds

• Includes bread yeast, mushrooms, and bread molds
• Cannot be killed by bacterial antibiotics
• Made from mold but does not act on it

22
Diseases Caused by Yeasts and Molds

• Candidiasis
• Covered by mucus in areas such as the inside of
  the mouth or the vaginal area
• Treated by antibiotics

23
Diseases Caused by Yeasts and Molds

• Tinea
• Appearance named according to site infected
• Tinea pedis (Athletes foot)
• Tinea corporis (Ringworm)
• Tinea unguium
• White patches on toe or fingernail

24
Diseases Caused by Yeasts and Molds

• Prion (pree-on)
• Proteinaceous infectious particles made of only
  protein
• Mad Cow Disease
• Creutzfeldt-Jacob Disease

25
Viruses

• Must live inside hosts
• Antibiotics cannot kill the virus
• Treatment is primarily to ease the symptoms for
  the patients comfort

26
Diseases Caused by Viruses

• Measles
• Rash, fever
• Spread by airborne droplets of nasal secretions
• Mumps
• Swelling of the parotid (salivary) glands on one
  or both sides
• Spread by airborne droplets

27
Diseases Caused by Viruses

• Rubella or German measles
• Rash on face may spread to trunk and limbs
• Only serious when it affects women in early
  stages of pregnancy
• May cause birth defects
• Vaccines are highly effective and given to most
  infants at age 15 months

28
Diseases Caused by Viruses

• Poliomyelitis or polio
• Attacks the central nervous system
• Severe paralysis is a possibility

29
Diseases Caused by Viruses

• Chicken pox
• Very common and contagious in children
• Rash and fever
• Spread through airborne droplets
• Usually only contract once in a lifetime
• Before age 10 is better than as an adult

30
Diseases Caused by Viruses

• Common cold and influenza
• Treatments for fever, upset stomach, headache,
  body ache
• Cold is spread through airborne droplets, contact
  with contaminated objects, or hand-to-hand contact

31
Diseases Caused by Viruses

• Common cold and influenza
• Flu vaccines are successful in 60 percent of
  patients
• Flu is contagious from 12 to 72 hours after
  symptoms appear
• Flu is spread through airborne droplets

32
Diseases of Major Concern to the Dental Assistant

• Herpes simplex virus (HSV)
• Herpes simplex virus I (HSV I) is associated with
  infections of the lips, mouth, and face
• Herpes simplex virus II (HSV II) is associated
  with the genital area
• Can also be found in oral cavity

33
Diseases of Major Concern to the Dental Assistant

• Treatment of HSV I
• Depends on its type, site, and severity
• Dental teams may reschedule patient if sores are
  apparent
• Primarily for patient comfort, although some
  offices may have policies
• Many treatments readily available

34
Diseases of Major Concern to the Dental Assistant

• Bloodborne diseases
• Hepatitis B
• Human immunodeficiency virus (HIV)
• Brain damage and dementia may occur
• May develop into acquired immune deficiency
  syndrome (AIDS)
• No cure
• Much research is being done to find a cure

35
Diseases of Major Concern to the Dental Assistant

• High risk behavior
• Injuries or sticks with sharp objects
  contaminated with blood or body fluid
• Multiple sexual partners unprotected sex
• Sharing contaminated needles
• Exposure to non-intact skin or open wound with
  contaminated blood or body fluid

36
Diseases of Major Concern to the Dental Assistant

• Viral hepatitis
• Hepatitis A and E
• Transmitted by personal contact or ingestion of
  contaminated water or food
• Vaccines and boosters are available for children
  in areas at high risk

37
Diseases of Major Concern to the Dental Assistant

• Viral hepatitis
• Hepatitis B (major dental concern)
• Transmitted mainly through needles and syringes
• May or may not have symptoms
• Loss of appetite, abdominal pain and tenderness,
  fever, weakness, muscle pain, and jaundice

38
How the Body Resists Diseases

• Infection
• Pyogenic membrane
• Dam built around infected area preventing it to
  spread further
• Antibodies
• Produced as a final defense against foreign
  substances

39
How the Body Resists Diseases

• Infection
• Antitoxins
• Neutralizes the toxins given off by certain
  bacteria

40
How the Body Resists Diseases

• Fever
• Fights off infection or pathogens
• Few bacteria can survive beyond 102 F

41
How the Body Resists Diseases

• Inflammation
• Increase in blood vessels to a specific area
  allowing antibodies to enter
• Erythema (redness)
• Heat
• Edema (swelling)
• Pain

42
How the Body Resists Diseases

• Immunity
• Ability to resist disease
• Natural
• Acquired
• Passive acquired
• Active acquired
• Natural acquired
• Artificial acquired

43
How the Body Resists Diseases

• Antigen substance injected into body to stimulate
  specific antibodies
• Allergens
• Hypersensitive
• Anaphylactic shock
• Sometimes fatal
• Requires going through patients health history

44
Normal Routes of Microorganism Exposure

• Direct contact
• When a dental provider touches the lesion or
  blood of an infected person while working in the
  oral cavity
• Standard precautions

45
Normal Routes of Microorganism Exposure

• Indirect contact
• When dental provider or next patient obtains
  disease from contaminated instruments, supplies,
  or equipment
• Standard precautions

46
Normal Routes of Microorganism Exposure

• Inhalation
• Takes place during use of high-speed handpiece
• Creates an aerosol spray during patient care