Questions 2013 Flashcards
With horizontal root fracture, what happens to the apical portion?
Stays vital
PCO
Problems with retrograde preparation?
1) Angulation, Perforation of the root end/cavity prep (not following long axis of the tooth)
2) Insufficient depth for retention of the root end filling
3) Pressing tip too hard and not allowing to move freely- could result in dev of microfractures/cracks (Calzonetti says no)
4) Use without adequate irrigation causing extreme temperature rise in periradicular tissues
5) Inadequate preparation of isthmus if present, and non through debridement of tissue debris or failure to remove all GP
6) Chipping resected surface
7) Grooving resected surface
3 requirements to do retro preparation
1) 3mm of root end cleaned and shaped
2) Preparation parallel to pulp space
3) Remove isthmus of all tissue and filling
Necrosis % in avulsed teeth according to Andreasen, after reposition?
Andreasen 1984
Monkey study
20% necrotic with immature apex
100% necrotic with mature apex
Histologic analysis showed that the extent of vital pulp was significantly related to the stage of root development, being almost complete in teeth with immature roots and almost totally lacking in young mature and mature teeth. Surface resorption was found with the same frequency in the different root development groups while inflammatory resorption was slightly more frequent in young mature teeth than in mature teeth, a finding possibly related to a protective action of a thick cementum layer in the mature teeth. Replacement resorption was found with almost the same frequency in the different root development groups in non-endodontically treated teeth.
Cranial trauma Signs and symptoms
Mild traumatic brain injury • Loss of consciousness for a few seconds to a few minutes • No loss of consciousness, but a state of being dazed, confused or disoriented • Memory or concentration problems • Headache • Dizziness or loss of balance • Nausea or vomiting • Sensory problems, such as blurred vision, ringing in the ears or a bad taste in the mouth • Sensitivity to light or sound • Mood changes or mood swings • Feeling depressed or anxious • Fatigue or drowsiness • Difficulty sleeping • Sleeping more than usual
Moderate to severe traumatic brain injuries
Any of the above PLUS any of these:
• Loss of consciousness from several minutes to hours
• Profound confusion
• Agitation, combativeness or other unusual behavior
• Slurred speech
• Inability to awaken from sleep
• Weakness or numbness in fingers and toes
• Loss of coordination
• Persistent headache or headache that worsens
• Repeated vomiting or nausea
• Convulsions or seizures
• Dilation of one or both pupils of the eyes
• Clear fluids draining from the nose or ears
Cushings triad indicates increased intracranial pressure (ICP)
- A change in respirations, often irregular and deep
- A widening pulse pressure (the difference between the Systolic and the Diastolic BP)
- Bradycardia (slow heart rate).
apexification w/ CaOH2 Disadvantages
1) Length of time which may be variable (5-20mths)
2) Unpredictability of apical closure
3) Difficulty in patient follow-up
4) Delayed treatment
5) Decrease in flexural strength and modulus of elasticity of dentin
Hemophelia characteristics
Hemophilia A: inherited deficiency Factor VIII (prolonged PTT)
Hemophilia B: inherited deficiency Factor IX (prolonged PTT)
–> x-linked, recessive
–> frequent, severe bleeds, internal bleeding and joints bleed, bruises, hematomas, swelngs
–> Prolonged PTT (intrinsic pathway)
Tx: multidisciplinary approach, schedule on the day patient receives factor replacement therapy, DDAVP, antifibrinolytic meds, hemostatic agents, avoid ASA, avoid IAN block, consider a surgical splint, avoid epi (rebound VD)
von Willebrand disease characteristics
vWD –> deficiency in vWF
–> Prolonged bleeding time (platelet aggregation)
Sickle Cell Anemia
Sickle cell anemia –> abnormal hemoglobin S which remains deoxygenated. Abnormal RBC shape –> obstruction of microvasculature –> stasis –> organ damage
Patient can present with “bone pain” which can mimic tooth pain and bone patterns which can mimic apical periodontitis.
Radiographic changes: decreased trabeculation, thin inferior border of mandible, coarse trabecular bone pattern - step-ladder appearance between molar roots (prominant horizontal trabeculae), dense lamina dura.
Tx: consider pre/post-op antibiotics (want to treat infections agressively), keep appts short.
Leukemia
Abnormal WBC.
Can be:
- lymphocytic (lymphocytes usually B cells)
- myeloid (RBC, granulocytes, monocytes, platelets)
- Acute (increased number of immature cells)
- Chronic (increased number of mature, abnormal cells)
Symptoms may include bleeding and bruising problems, feeling very tired, fever and an increased risk of infections.
Dental manifestations:
- Oral bleeding
- Petechiae
- Gingival swelling
- Mucosal ulcers
- Candidiasis / oral thrush
- Oral infection is common
Management: Hematological infromation is needed before any surgical procedures. (increased bleeding tendencies and susceptibility to infection)
-Obtain med consult
-Antibiotic coverage (pre/post surgical)
Chose RCT over exo.
-avoid routine dental care for patient with acute symptoms and can proceed with indicated dental care once disease is under control
Anemia
Decreased RBC, decreased hemoglobin.
Caused by:
- blood loss
- hemolysis
- ineffective hemopoiesis
Symptoms:
Usual symptoms are weakness, or fatigue, general malaise, and sometimes poor concentration. Can also present with dyspnea (shortness of breath) on exertion. Potentially increased cardiac output, palor, jaundice, pica (weird eating habbits)
Thalassemia
Decreased in production of alpha or beta chains of hemoglobin.
People with Thalassemia have overactive bone marrow leading to thick head and face bones –> malocclusion, macroglossia, spacing between teeth, weak arms that fracture easily.
They are often overloaded with iron due to frequent blood transfusions, and are usually on bisphosphonates.
Management: discuss tx plan with hematologist,
- adjust treatment time with blood transfusion
- antibiotic coverage
Multiple Myeloma
Plasma cell tumours – bone tumours, anemia, bleeding problems
Dental relevance - lesions in the jaw, pts on bisphosphonates, radiographic changes (generalized bone rarifaction, osteoporotic appearance)
Perforation management
Repair perfs immediately (reduce chance of contamination, lesion formation, communication with oral env, etc)
Prognosis affected by:
1) Location of perforation
2) Time delay before perforation repair
3) Ability to seal the defect
4) Previous contamination with MOs
5) Size?
6) use of MTA
Mente 2014 –> 86% healed regardless of location (repaired with MTA0
Valerie Pontius 2013 –> 94% healing (multiple materials but mostly MTA) and 77% if location is crestal.
Krupp 2013 –> 73% healed overall, but prognosis decreases if there is a pre-op radiolucency around the perf, or if it communicates with the oral flora
Clindamycin and pseudomembranous colitis
Pseudomembranous colitis is inflammation of the colon and often caused by an overgrowth of Clostridium difficile usually following the use of a broad spectrum antibiotic such as Clindamycin.
Risk factors: elderly, females with gatrointestinal disease, weakened immune system
Drugs implicated: cephalosporins, ampicillin, clindamycin, other penicillins, erythromycin and others.
• Watery diarrhea (bloody in some cases) >48 h
• Abdominal cramps, lower quadrant abdominal tenderness
• Fever, leukocytosis
TX: stop all antibiotics, refer to physician immediately, hydration. Most cases remit if antibiotic withdrawn early.
Treated with vancomycin 500mg QID p.o in first two days if severe or 125mg QID for 10-14 days; or metronidazole 500mg TID for 7-14 days
ASA 300-325mg 1-2 q4-6h (effect on platelets)
ASA prevents platelet aggregation. It inhibits cyclooxygenase 1 and 2 enzymes (non specifically). The enzyme cyclooxygenase is needed for the generation of thromboxane, a product of platelets. Thromboxane, is needed to induce platelet aggregation.
ASA irreversibly blocks the formation of thromboxane A2 in platelets producing an inhibitory effect on platelet aggregation. Mature platelets only express COX1 which is highly sensitive to low dose ASA.
650 mg of aspirin doubles the bleeding time for 4-7 days.
What are 4 components of 2% Lidocaine 1:100,000 epi local anaesthetic carpule?
- Anaesthetic (Lidocaine)
- Vasoconstrictor (Epinephrine)
- Preservative (Sodium Bisulfate - only when epi is present)
- Vehicle to make solution isotonic (Distilled water,
Sodium Chloride)
Plain anesthetic would only have 2 components (anesthetic and NaCl)
Carbamide peroxide break down produces ammonia, urea, CO2 and what other product
hydrogen peroxide
mecanism of carbamide peroxide bleaching.
Acts as an oxidizing agent
10% Carbamide peroxide is most common
MOA: It is the hydrogen peroxide in carbamide peroxide which diffuses through the enamel and dentin producing free radicals which interact with pigment molecules breaking their double bonds.
It is possible that the refractory/relapse in bleaching may be due to reformation of these double bonds
What are concerns with use of doxycycline in combination irrigants?
- resistance
- staining
(MTAD=Mixture Tetracycline (doxycycline) Citric Acid and Detergent)
It has been shown that if MTAD is used with NaOCl the antimicrobial effect of MTAD was lost due to oxidation of the MTAD by NaOCl
Doxycycline is only bacteriostatic
In vitro studies showed good antibacterial activity, later clinical studies showed a lesser antimicrobial effect (Malkhassian 2009)
US – what is the energy called when a crystal is used and energy is converted into oscillation?
Piezoelectricity
Bystrom ’81 – give two conclusions that were drawn from his study.
- mechanical instrumentation and irrigation with saline reduced the number of bacteria in the root canal by 2-3 log
- supporting action of disinfectants would be necessary for successful removal of the bacteria from the root canal.
- There was no evidence that specific microorganisms were implicated in these persistent infections
Langeland 1977-what was the correlation between inflammation and signs and symptoms?
there was no correlation between the presence of various inflammatory cells and the clinical signs and symptoms of the patients
