What is hepatitis?
Inflammation of the liver. Caused by:
-Infection, bacterial or viral
There are types A to E and also herpes viruses (Epstein Barr) are a form of viral hepatitis.
What are the complications of hepatitis?
-HBV responsible for over 1,000,000 deaths p.a. worldwide
-Over 350,000,000 chronic carriers worldwide. Most prevalent in Western Africa and Indo-China
What is the risk of inoculation of HIV compared to Hep B?
Much higher risk of getting Hep B from a needlestick injury compared to HIV.
What is hepatitis D (delta agent)
*Rides piggyback on HBV as incomplete RNA virus and replicates only in presence of HBV
*Clinically similar to HBV but increased mortality
*HBV vaccination protects against delta agent
What is hepatits C?
-Recognised in 1989
-Accounts for 90% of post transfusion Non-A Non-B Hepatitis
-Parenteral, rarely sexual, vertical transmission
-Salivary transmission has been observed experimentally in animals
-Over 170,000,000 carriers worldwide
How is Hep C diagnosed?
-Detection of Anti-HCV antibody
-Seroconversion may be delayed for several months
-PCR techniques to amplify HCV RNA may be used to diagnose acute infection
-Higher incidence of developing Hepatocellular carcinoma than with HepB
How can Hep C be treated?
-Interferon alpha can be given but 50-80% of patients regress after stopping treatment within 6 months
-Ribavarin can be given and has been shown to reduce serum levels of HCV RNA
What's the incidence of Hep B and Hep C?
• Highest prevalence 15-44 years
• Peak incidence 25-34 years
• M:F 1.5:1
• Highest prevalence 25-44 years
• M:F 2:1
What is the risk of HCVseroconversion following a
needlestick with HCV contaminated blood?
Can be as high as 10%
What are prions?
• Proteinaceous Infectious Particles
• <30nm in size
• Not uniformly distributed in tissue
• Resistant to chemical and physical destruction
• Agents causing Transmissible Spongiform Encephalopathies (TSE’s)
What are Transmissible Spongiform Encephalopathies (TSE’s)?
• A group of diseases characterised by spongiform change in the CNS
• First described in sheep 200 years ago (Scrapie)
• More recently described in cattle (BSE)
What are human forms of TSE's? (Transmissible Spongiform Encephalopathies)
•Sporadic Creutzfeldt Jakob Disease (CJD)
•Familial Creutzfeldt Jakob Disease (CJD)
-Fatal Familial Insomnia
•Iatrogenic Creutzfeldt Jakob Disease (CJD)
•Variant Creutzfeldt Jakob Disease (vCJD)
What is CJD?
• 3 types recognised:
-Sporadic CJD (Majority of cases 85%)
-Familial CJD (10% of cases)
-Varient CJD (link BSE)
• Any of these may cause iatragenic CJD if transmitted directly (1% cases per year)
What are the clinical features of variant CJD?
• Lower mean age of onset than sporadic (29 vs 60 years)
• Longer duration of illness (14m v 5m)
• Early psychiatric changes, sensory symptoms and
What is the transmission of vCJD?
Documented human to human transmission:
• Dural grafts
• Corneal grafts
• Blood products (from infected pool)
• Inadequate sterilisation of surgical instruments
• Human growth hormone & gonadotrophins
• Ritual cannibalism
What are the chemicals & processes possibly
effective against TSE agents?
• Sodium Hypochlorite 20,000 ppm available chlorine for 1 hour
• Sodium Hydroxide 2M for 1 hour
• Non-porous load steam steriliser 134-137º for 18 mins holding time, or 6 x 3 min cycles
• None of these methods guaranteed
• BDA takes advice for the Health Departments
• Thorough cleaning of instruments prior to autoclaving
• Single use items where possible
• Use single use instruments when dealing with CNS tissue
• Root canal treatment single use reamers & files
What's the dental management of TSE's?
•At risk groups TSE’s (5000 in UK)
• Corneal transplants
• Human dural grafts
• Growth Hormone
•Normal cross infection control measures
• Single use equipment. ? Dental set specific for
treating TSE infected individuals
What are these images portraying?
What can xerostomia do to the dentition?
What are bisphosphonates?
Bisphosphonates are a group of medicines used to treat conditions that affect your bones. Examples of these conditions include osteoporosis, Paget's disease of bone, and cancer that has spread to the bones (bone metastases). Bisphosphonates are also used to treat very high amounts of calcium in the blood in people who have cancer and are very ill.
What are the different types of bisphosphonates usually prescribed?
What's the dental problem with bisphosophates?
There is a very small chance of osteonecrosis of the jaw. This condition is when the jaw bone does not receive enough blood and the bone starts to weaken and die. It is usually painful, but not always. Usually goes away if bisphosphonates are no longer taken.