2012 U of T

Question 1

give 4 presenting features of irreversible pulpitis

Answer 1

a) pain restricted to a single tooth
b) pain relieved by a diagnostic LA block
c) prolonged sensitivity to cold, sensitivity to hot
d) tooth associated with trauma or dental caries or recent dental treatment

Question 2

give 4 presenting features of migrane

Answer 2

unilateral, pulsating, moderate to severe headaches lasting from two to 72 hours

2) nausea, vomiting, photophobia (increased sensitivity to light) and phonophobia (increased sensitivity to sound)
3) three times more common in women than in men
4) one-third of people who suffer from migraine headaches perceive an aura—transient visual, sensory, language, or motor disturbances signaling the migraine will soon occur

Question 3

give 4 presenting features of dentin hypersensitivity

Answer 3

a) pain not always restricted to a single tooth
b) pain relieved by a diagnostic LA block
c) sensitivity to cold that is not prolonged
d) pain relieved by use of desensitizing agent or restoration to cover exposed site

Question 4

give 4 presenting features of trigemnial neuralgia

Answer 4

a) severe shooting electric-like pain which lasts for a few seconds (10 % bilateral)
b) trigger points often found
c) not relieved by diagnostic LA block unless trigger point is frozen
d) normal thermal tests of teeth
extra: not always restricted to tooth

Question 5

give 4 presenting features of temporal arteritis

Answer 5

a) Throbbing headache on one side of the head or the back of the head
b) Fever, malaise and Excessive sweating, loss of appetite and weight loss
c) Jaw pain or painful jaw muscles
d) Vision difficulties: Blurred vision, Double vision, Reduced vision and hearing difficulties
e) temples sore to touch
d) diagnosed by biopsy (giant cells)

Question 6

give 4 presenting features of TMD

Answer 6

1) Pain or tenderness in the face, TMJ area, neck and shoulders, and in or around the ear when you chew, speak, or open your mouth wide
2) Limited ability to open the mouth very wide
3) Clicking, or grating sounds in the TMJ when opening or closing the mouth (+/- pain)
4) Aching pain in the face, Ear ache or Headache (particularly in the morning)

Question 7

give 4 presenting features of acute sinusitis

Answer 7

Headache/facial pain, toothache, pain behind the eyes or pressure of constant, or aching sort

2) Pain is localized to the sinus and may worsen when the person bends over or lying down, may cross with time.
3) Precipitated by an earlier upper respiratory tract infection
4) Fatigue and generally not feeling well +/- Fever
5) Nasal stuffiness and discharge

Question 8

give 4 presenting features of shingles

Answer 8

1) headache, fever, and malaise
2) painful skin or paresthesia
3) unilateral (does not cross midline), dermatome pattern
4) rash with blisters

Question 9

What is the most common age group affected by shingles?

Answer 9

60+

Question 10

List 5 indications for antibiotics use in endodontics.

Answer 10

a) AHA Prophylaxis
b) Diffuse swelling (Cellulitis)
c) Localized swelling without drainage
d) Rapidly increasing swelling
e) Systemic signs (Fever, Lymphadenopathy, unexplained trismus)
g) Trauma
h) Regeneration

Question 11

List 4 cardiac conditions that need prophylactic antibiotics.

Answer 11

a) Artificial heart valves
b) History of infective endocarditis
c) Cardiac transplant that develops a valve problem
d) Certain congenital heart conditions:
i. Unrepaired cyanotic congenital heart disease
ii. Repaired congenital heart disease with prosthetic material within the last 6 months
iii. Repaired congenital heart disease with residual defects
a) Artificial heart valves
b) History of infective endocarditis
c) Cardiac transplant that develops a valve problem
d) Certain congenital heart conditions:
i. Unrepaired cyanotic congenital heart disease
ii. Repaired congenital heart disease with prosthetic material within the last 6 months
iii. Repaired congenital heart disease with residual defects

Question 12

What is normally prescribed for an adult as a prophylactic antibiotic, give name and dose.

Answer 12

Oral Amoxicillin 2 grams (adults) or 50 mg/kg (children) 1 hour prior to dental treatment.

Question 13

If the patient has pen allergy, give 3 antibiotics (and their dose) that can be prescribed for prophylaxis.

Answer 13

a) Clindamycin 600mg (adults) or 20 mg/kg (children)
b) Azithromycin (preg b) or Clarithromycin (preg C) 500 mg (adults) or 15 mg/kg
(children)
c) Cephalexin 2 grams (adults) or 50 mg/kg (children)

We don’t use erythromycin because Azithromycin and clarithromycin have better pharmacokinetic properties than erythromycin. They also have a higher bioavailability, less drug-drug interaction and a longer duration of effect. They also have less gastrointestinal effects than erythromycin and less likely to cause arrhythmias and ototoxicity. Erythromycin is arrhythmogeninc.

Question 14

An instrument is rotating in a canal and the tip binds, but the motor continues to rotate. As a results the instrument fractures – what is this type of fracture called?

Answer 14

Torsion stress is the stress on the instrument when it is bound at the tip and rotated about its axis.

Question 15

An instrument is rotating in a curved canal and the tensile and compressive stresses that occur as a result cause fracture – what is this type of fracture called?

Answer 15

Cyclic fatigue fracture occurs when an endodontic instrument rotates in a curved canal. In this condition, the instrument under elastic deformation is subjected to a mechanical load represented by alternating tensile and compressive stresses. The cyclical repetition of the load leads to instrument fracture through low-cycle fatigue. The cyclic fatigue resistance comprises the number of cycles that an instrument can endure under a specific loading condition until fracture occurs. Because the number of cycles to fracture is cumulative, it can be calculated by multiplying the rotation speed by the time elapsed until fatigue fracture occurs. (Lopes 2010)

Question 16

Does the risk of cyclic fatigue fractures increase or decrease when the degree of curvature increases?

Answer 16

Increases

Question 17

Does the fracture resistance to cyclic fatigue increase or decrease when the diameter of the file is increased?

Answer 17

decrease

Question 18

Which part of the triple antibiotic paste results in potential discoloration?

Answer 18

Minocycline

Question 19

What are 3 things that can be done to reduce the risk of discoloration?

Answer 19

a) Place paste to maximum height of CEJ
b) Placed bonded flowable composite over inside of access cavity sealing dentinal tubules before placing paste
c) Place bonded restoration for temporary
d) Advise patient of possible discoloration and to contact office if begins to discolor
e) Do not use Minocycline or use alternative

Question 20

How does dentin demineralize?

Answer 20

Dentin demineralization and destruction-oral microbes produce acids such as lactate, acetate and propionate, which dissolve inorganic minerals, hydroxyapatite crystallites, first from the enamel, and then from dentin (Hojo et al. 1991, van Houte 1994). As a consequence of an acidic environment, the collagenous matrix of dentin is demineralized, leading to a caries lesion. However, bacterial acids are not able to hydrolyze fibrous collagens, therefore fail to degrade the dentin organic matrix (Katz et al. 1987, van Strijp et al. 1997). Host enzymes, matrix metalloproteinases, degrade the dentin matrix during or after demineralization by bacterial acids (Tjäderhane et al. 1998a, Sulkala et al. 2001). Such host proteases, either from odontoblasts or pulp tissue may be responsible for collagen matrix destruction, and in combination with additional hydrolytic enzymes such as lactate dehydrogenase (LDH) and glycoproteases, may catalyze dentin connective tissue degradation in caries progression. In physiological conditions, proteolytic enzymes may in turn model calcified matrix. (Larmas 2001.)

Question 21

Lido 2% 1:100,000 epi – how much epi is there in 2 carps?

Answer 21

1: 100,000=1000g/100000ml=0.001g/100mL=0.01mg/mL

0. 01mg/mL X 3.6mL =0.036 mg

Question 22

Lido 2% 1:100,000 epi – how much lido is there in 1 carp?

Answer 22

2% lidocaine is 20mg/ml

20mg/ml x 1.8 = 36mg

Question 23

Max dose of lidocaine?

Answer 23

7mg/kg

Question 24

Max dose of articaine?

Answer 24

7mg/kg

Question 25

Max dose of Bupivicaine

Answer 25

2mg/kg

Question 26

Max dose of Prilocaine

Answer 26

8mg/kg

Question 27

Max dose of Mepivicaine

Answer 27

6.6mg/kg

Question 28

Calculate the maximum number of cartridges for a 60 kg non-pregnant patient of 2% lidocaine local anaesthetics. Show your calculations.

Answer 28

``` Maximum dose of lidocaine is 7mg/kg 60kg x 7mg/kg = 420mg (maximum amount of lidcaine) 2% lidocaine = 20mg/ml they can have 420mg / 20mg/ml=21ml 21/1.8 = 11.6 carpules ```

Question 29

What is the maximum number of carpules of 4% prilocaine?

Answer 29

) 4 grams prilocaine per 100mL=40g/1000mL=40mg/mL 40mg/mL X 1.8mL = 72 mg of prilocaine/cartridge 60kg X 8mg/kg (max dose prilocaine) = 480mg prilocaine 480mg/72 mg prilocaine = 6.7 cartridges max

Question 30

What are 2 purposes of electropolishing an endodontic instrument?

Answer 30

a) Reduce microfracture by reducing surface irregularities | b) Reduce corrosion

Question 31

List 5 reasons for coronal leakage.

Answer 31

a) Inadequate temporary seal between and after treatment b) Inadequate timeliness of the final restoration c) Choice and integrity of the final restoration material d) Pre-endodontic tooth preparation e) Traumatic occlusion

Question 32

List 6 properties of an ideal intracanal irrigant.

Answer 32

a) Antimicrobial b) Substantivity c) Removes smear layer d) Penetrates into dental tubules e) Water soluble f) Low cytotoxicity g) Allergy is rare e) Cheap

Question 33

What are 4 components of 2% Lidocaine 1:100,000 epi local anaesthetic carpule?

Answer 33

Carpule: glass cartridge, rubber stopper, Metal Cap & Rubber Diaphragm Lidocaine, epinephrine, sodium bisulfite, distilled water, sodium chloride

Question 34

Goals of revascularization?

Answer 34

a. treating and preventing apical periodontitis b. triggering continued root development c. restoring functional competence of the pulp tissue

Question 35

How long would you expect it to take to get a positive sensibility test after revascularization?

Answer 35

6 months (Torabinejad & Turman, 2011)

Question 36

How would you determine if your revascularization procedure was successful?

Answer 36

Radiological exam, absence of symptoms, sensibility

Question 37

Clotting mechanism fill in the blanks (6) such as the end result of the intrinsic pathway? Coagulation – platelet function – COX2 involvement.

Answer 37

The crucial step in both clotting mechanisms is the conversion of fibrinogen to fibrin. The fibrinogen is a plasma protein formed by the liver that is constantly in circulation in the blood. The polymerization and linkage of these molecules into interconnecting strands forms a thread-like network entrapping serum fractions and formed elements. This forms a hydrated, gelated aggregete termed the fibrin clot that strengthen the platelet plug and form the initial seal between the oral environment and the wound edges.

Question 38

What are the percentages of organic to inorganic dentin matrix?

Answer 38

by weight, 70% inorganic, 20% organic, 10% water (and 45%, 33%, and 22% by volume). * * phosphophoryn (dentin phosphoprotein) a highly phosphorylated, tissue specific molecule that is unique to the odontoblast cell lineage, thought to bind to calcium and play a role in mineralization.

Question 39

What is the principle type of collagen in dentin

Answer 39

91% of the organic, is collagen, type 1, minor component type V

Question 40

What is the principle inorganic component of dentin?

Answer 40

Ca10(P04)6(OH)2 (hydroxyapatite).

Question 41

What are the principle inorganic (non-collagenous) components of dentin?

Answer 41

Noncollagenous matrix components include phosphoproteins, proteoglycans (dermatan sulfate, heparan sulfate, hyaluronate, keratan sulfate, chondroitin 4 sulfate, chondroitin 6 sulfate), gamma carboxyglutamate containing proteins, acidic glycoproteins, growth factors, and lipids.

Question 42

What is the precipitate called when mixing sodium hypochlorite and chlorhexidine and why is of concern?

Answer 42

Parachloroaniline

Question 43

Does EDTA have strong antimicrobial properties?

Answer 43

No, Torabinejad, 2003?

Question 44

How to increase efficacy of NaOCL?

Answer 44

``` use fresh solution replenish solution increase time temperature concentration agitation ```

Question 45

What does buffering do to NaOCL?

Answer 45

No effect. Zehnder et al., 2002 In contrast to earlier statements, the results of this study do not demonstrate any benefit from buffering sodium hypochlorite with sodium bicarbonate according to Dakin's method. An irrigation solution with less dissolving potential may be obtained by simply diluting stock solutions of NaOCl with water.

Question 46

What are the breakdown products of Carbamide peroxide? and what other product?

Answer 46

hydrogen peroxide, ammonia, urea, CO2

Question 47

What are concerns with use of doxycycline in combination irrigants?

Answer 47

a) resistance to the antibiotic | b) staining of the tooth

Question 48

US – what is the energy called when a crystal is used and energy is converted into oscillation?

Answer 48

Piezoelectricity

Question 49

Uses of USonics in endo.

Answer 49

PUI Retro preparation Posts/Broken instruments removal Active preparation, removing dentin during CS

Question 50

Does increase in intensity of PUI lead to improved irrigation dynamic – give quote.

Answer 50

No, | Ahmad et al., 87, Lea et al., 2004

Question 51

Why air water and removing posts?

Answer 51

Ingle: Heat build up and transmission to PDL (prevention)

Question 52

What is cavitation and is it important in endo?

Answer 52

Cavitation is the formation of vapour cavities in a liquid through tensile forces induced by high-speed flow or flow gradient. Occurs when a liquid is subjected to rapid changes of pressure that cause the formation of cavities where the pressure is relatively low. When subjected to higher pressure, the voids implode and can generate an intense shockwave. Important for :Bacteria, smear layer.

Question 53

What is acoustic streaming and why important?

Answer 53

Rapid movement of fluid in a circular or vortex-like motion around a vibrating file (Walmsley, 87) Shear stress along the root canal wall, removes debris and bacteria from walls.

Question 54

What is a prion?

Answer 54

Prion: A small proteinaceous infectious disease-causing agent that is believed to be the smallest infectious particle. A prion is neither bacterial nor fungal nor viral and contains no genetic material. Prions have been held responsible for a number of degenerative brain diseases, including mad cow disease, Creutzfeldt-Jakob disease, fatal familial insomnia, kuru, and an unusual form of hereditary dementia known as Gertsmann-Straeussler-Scheinker disease.

Question 55

What disease is most commonly associated with prions?

Answer 55

Transmissible Spongiform Encephalopathy (TSE) or (Creutzfeldt-Jakob Disease)

Question 56

Are there any studies that show prions are in pulp?

Answer 56

No (human), Blanquet-Grossard F et al., 2000. Only in brain, trigeminal ganglia and tonsils, Head et al., 2003.

Question 57

What are 2 recommendations from AAE regarding single use instruments?

Answer 57

1) The committee does not deem it necessary to recommend that all endodontic hand and rotary files and reamers be designated as single use items at this time. 2) Does recommend that the clinicians continue to adopt a vigilant and cautious approach in monitoring pts health, use acceptable methods to clean and sterilize endodontic instruments, and exercise sound clinical judgment in the selection of instruments for re-use. Recommended, when a pt with confirmed CJD receives endodontic treatment, all instruments used in the root canal to be discarded.

Question 58

How do manufacturers ensure that instruments are single use?

Answer 58

Thermosensitive part.

Question 59

Torneck 66/67 – give 2 conclusions from this study that responded to Rickett’s Hollow Tube Theory

Answer 59

a) Disproved the hollow tube theory by implanting sterile hollow needles and demonstrating minimal tissue response b) Showed canals did not need to be completely obturated to prevent tissue irritation and inflammation.

Question 60

Bhaskar study – maxillary vs. mandibular cyst (%) and why.?

Answer 60

48% granulomas, 42% cysts. The incidence of cysts in maxilla:madible is 10:1 due to far greater epithelial debris in the maxilla.

Question 61

Kuttler study (2 findings).

Answer 61

The apical foramen is the circumference that differentiates the termination of the cemental canal from the exterior surface of the root, diameter varies: a) 18-25yrs= 502um, center of foramen located 32% centre/68% on the side b) >55yrs=681um, center of foramen located 20% in centre of apex/80% on the side

Question 62

Byrnolf ’67 – what is the percentage of teeth that didn’t show inflammation?

Answer 62

Histologic and radiographic exam indicated complete healing following RCT occurring only 7%. 93% had inflammation despite no radiolucency. Green 1997: 74% of the teeth with normal radiographic findings showed NO inflammation.

Question 63

List 2 limitations to Brynolf’s (’67) results as described by Green ’97.

Answer 63

a) Preparation and obturation techniques (chloropercha) | b) Methods of radiographic and histological analysis

Question 64

Bystrom ’81 – give two conclusions that were drawn from his study.

Answer 64

a) instrumentation alone redduced bactera l0^2- l0^3 (2-3 log). Instrumentation alone was not enough to b) There was no evidence that specific microorganisms were implicated in these persistent infections. Teeth where the infection persisted despite being treated five times were those with a high number of bacteria in the initial sample.

Question 65

Langeland 1977-what was the correlation between inflammation and signs and symptoms?

Answer 65

Histopathologic and histo-bacteriologic studies of the specimens showed that there was no correlation between the presence of various inflammatory cells and the clinical signs and symptoms of the patients.

Question 66

Patient needs endodontic surgery but has coagulation disorders (e.g. hemophilia or sickle cell anemia). What are the adverse affects and their causes and what is the management?

Answer 66

Look it up!

Question 67

Patient needs endodontic surgery but has radiation of head and neck for cancer. What are the adverse affects and their causes and what is the management?

Answer 67

What do you need to know this for?

Question 68

Patient needs endodontic surgery but has received. IV bisphosphonates for osteoporosis. What are the adverse affects and their causes and what is the management?

Answer 68

Look it up yourself!

Question 69

What is the ‘success’ of a tooth with a fractured instrument? Give a reference with approximate %.

Answer 69

Spili 2005: fractured instrument 91.8% vs 94.5% without a fractured instrument 87: 93 (necrotic) "In the hands of experienced operators, endodontic instrument fracture, in particular rotary NiTi, had no adverse influence on the outcome of nonsurgical root canal treatment and retreatment when the instrument remained in the root canal. The presence of a preoperative periapical radiolucency, rather than the fractured instrument per se, was a more clinically significant prognostic indicator." Ng 2011: NSRCT outcome with no fractured instrument=82.9% and with =80% (NSD); retreatment outcome fractured instrument=80.4% and with=50 (SD).

Question 70

What is the key factor in determining the outcome?

Answer 70

Crump and Natkin 1970: Location and the prior debridement / shaping of the canal system.

Question 71

What are 3 mechanisms of teeth to resist caries invasion?

Answer 71

a) reactionary dentin b) reparative dentin c) dentin sclerosis

Question 72

What are the 3 prominent cells during low grade caries infection?

Answer 72

a) macrophages b) plasma cells c) lymphocytes

Question 73

List 5 chemical mediators on vasculature and their origin.

Answer 73

a) Substance P from Sensory nerves (vasodilation, increase vascular permability) b) Neurkinin A from Sensory nerves (increase vascular permability) c) Calcitonin gene-related peptide from sensory nerves (vasodilation) d) Neuropeptide Y from sympathetic nerves (vasoconstriction) e) Vasoactive intestinal peptide (VIP) parasympathetic nerves (Vasodilation)

Question 74

19. List 5 spaces that can result in a cavernous sinus thrombosis. (5)

Answer 74

a) Lateral pharyngeal b) Buccal c) Infratemporal d) Canine e) Retropharyngea f) pterygomandibular?

Question 75

Which teeth can cause such an infection? (cavernous sinus thrombosis)

Answer 75

Maxillary canines | Max premolars

Question 76

Siqueira ’00 – effect of 1% vs. 2.5%, 5.25% NaOCl on bacterial reduction?

Answer 76

in vitro microbiological study There was no significant difference between the three NaOCl solutions tested (p > 0.05). All NaOCl solutions were significantly more effective than saline solution. The results of this study suggest that regular exchange and the use of large amounts of irrigant should maintain the antibacterial effectiveness of the NaOCl solution, compensating for the effects of concentration. Recommends larger volume if use low concentration to compensate This paper did not look at tissue dissolution but mentioned: Baumgartner and Cuenin PR. 1992 Scanning electron microscopy to examine instrumented and uninstrumented surfaces in the middle third of root canals following the use of several concentrations of NaOCI (5.25%, 2.5%, 1.0%, and 0.5%). NaOCI was delivered with either an endodontic irrigation needle or an ultrasonic device. All of the concentrations of NaOCI with either delivery system were very effective in flushing out loose debris from the root canals. A smear layer with some exposed dentinal tubules was seen on all instrumented surfaces regardless of concentrationof NaOCI or irrigation device. NaOCI in concentrations of 5.25%, 2.5%, and 1% completely removed pulpal remnants and predentin from the uninstrumented surfaces. Although 0.5% NaOCI removed the majority of pulpal remnants and predentin from the uninstrumented surfaces, it left some fibrils on the surface.

Question 77

Baumgartner and Cuenin 1992 | effect of 1% vs. 2.5%, 5.25% NaOCl on smear layer?

Answer 77

A smear layer with some exposed dentinal tubules was seen on all instrumented surfaces regardless of concentrationof NaOCI or irrigation device. NaOCI in concentrations of 5.25%, 2.5%, and 1% completely removed pulpal remnants and predentin from the uninstrumented surfaces. Although 0.5% NaOCI removed the majority of pulpal remnants and predentin from the uninstrumented surfaces, it left some fibrils on the surface.

Question 78

Patient given antibiotic and comes back within 3 hours with a rash and hives. What type of hypersensitivity reaction is it?

Answer 78

Answer is Type 1 Hypersensitivity (igE mediated) Type 2 - Cytotoxic - Antibody (IgM or IgG) binds to antigen on a target cell, which is actually a host cell that is perceived by the immune system as foreign, NK cells bind to the other end of the antibody and degranulate leading to cellular destruction via the MAC. Type 3 - Immune complex - Antibody (IgG) binds to soluble antigen, forming a circulating immune complex. This is often deposited in the vessel walls of the joints and kidney, initiating a local inflammatory reaction. Type 4- Delayed hypersensitivity,cell-mediated immune memory response, (antibody-independent). Helper T cells (specifically Th1 helper t cells) are activated by an antigen presenting cell. When the antigen is presented again in the future, the memory Th1 cells will activate macrophages and cause an inflammatory response. This ultimately can lead to tissue damage. Leads to maculo-papular skin rash 2 days after exposure. Eg contact dermatitis. Type 5 - Autoimmune disease, receptor mediated- Graves' disease, Myasthenia gravis

Question 79

What are the steps that lead to immediate hypersensitivity.

Answer 79

Foreign particle (hapten) is too small to elicit T-cell response, but instead binds to host protein making immune system recognize "self" as "foreign". The body now forms antibodies to this "modified self" protein by eliciting a strong th-2 response. (macrophages phagocytose the "foreign" particle --> present antigen to Th-2 cells --> stimulate B cells to differentiate into plasma cells and produce IgE --> IgE secreted and attach to the surface of mast cells) Mast cells now have IgE antibodies on their surface. On repeated exposure--> antigen now interacts directly with mast cells by binding the IgE surface antibody--> trigger mast cell degranulation --> histamine release and other inflammatory mediators. This leads to: capillary dilation, increased permeability, smooth muscle contraction, airway constriction, mucus secretion, pain, itching, damage to local tissues.

Question 80

What is the management of the patient type 1 allergic reaction to pen?

Answer 80

``` stop antibiotic. Consider: antihistamine, epinephrine, corticosteroid. bronchodilator ```

Question 81

List 4 types of bone grafts and their sources

Answer 81

Xenograft-animal Autograft-self Allograft-donor Alloplast-synthetic or inert foreign body

Question 82

List 6 surgical outcome predictors.

Answer 82

``` preoperative lesion good filling =bad outcome re-surgery crypt size MTA vs super EBA ```

Question 83

``` Place in order: Systematic review RCT Case report Cross-sectional study Double blinded cohort Retrospective study ```

Answer 83

``` Systematic review RCT Double blinded cohort Retrospective study Cross-sectional study Case report ```

Question 84

List 3 types of sensory nerves in tooth.

Answer 84

a) Aβ – large myelinated, primarily respond to hydrodynamic stimuli (Narhi 1985) b) Aδ – smaller and slower than Aβ, lightly myelinated, c) C – unmyelinated, slowest

Question 85

PAN, PA radiograph, Occlusal radiograph – soap bubble lesion around 44/45 List the findings you see on the radiographs

Answer 85

Ameloblastoma, OKC (odontogenic keratocyst), glandular odontogenic cyst, simple bone cyst, odontogenic myxoma, giant cell granuloma, ossifying fibroma, central mucoepidermoid carcinoma

Question 86

What are three drug interactions involving Metronidazole?

Answer 86

a. anticoagulants- risk of bleeding. Monitor. b. disulfuram (antabuse)- acute psychosis, confusion. Avoid. c. phenytoin (dilantin) - (an antiepileptic) increased effect of ph. Monitor. d. Ethanol, lithium.

Question 87

What are 6 reasons that increase caries attack in the patient?

Answer 87

a) Diet-higher carbohydrates b) Saliva composition-less serous c) Saliva volume-lower d) Mouth breathing e) Immune factors-lower concentrations f) No water fluorination g) Lack of dental hygiene-no brushing or flossing h) No sealants placed i) Medications j) Systemic health/conditions

Question 88

Does Clindamycin have a low level or a high level of protein binding?

Answer 88

High binds 50s ribosomes

Question 89

What is the most commonly used antibitiotic for orofacial infections?

Answer 89

Amoxicilin

Question 90

What antibiotic is the broad spectrum version of the one above?

Answer 90

Amoxicillin/clavulanate

Question 91

According to Fuss and Trope 1996, what are 3 factors that determine success of perforation repair?

Answer 91

Time, size, location.

Question 92

Anesthetic treatment complication. options for a patient with trismus (causes and management)

Answer 92

causes of trismus: : trauma (intramuscular injection) to mm or blood vessels, (hemmorage), low grade infection, excessive volumes of LA into the area. Onset approx 1-6 days later heat therapy, saline rinse, analgesics and possibly muscle relaxants, if infected-consider Abx. Physiotherapy.

Question 93

Anesthetic treatment complication. options for a patient with diplopia, (causes and management).

Answer 93

The possible explanations given by John Crean and Alison Powis are as follows: (1) The inadvertent deposition of local anesthetic solution passes through the inferior orbital fissure to cause direct anesthesia of the abducent nerve. (2) The local anesthetic solution reaches the inferior ophthalmic vein via the pterygoid plexus or its communicating branches. This vein contains no valves and connects directly with the extrinsic muscles of the eye via the infraorbital foramen. An intraluminal injection may easily reverse the flow within the vessel, thus predisposing the muscles to the effect of the anesthetic solution. (3) Deposition of the anesthetic solution within the PSA artery causes a back flow into the connecting maxillary artery and subsequently into the middle menengial artery. There exists a constant anastomosis between the rbital branch of the middle menengial and the recurrent menengial division of the lacrimal branch of the ophthalmic artery. This lacrimal artery supplies the lateral rectus muscle, the lacrimal gland, and the outer half of the eyelids, which due to these anatomical considerations may explain these symptoms. (4) The local anesthetic solution reaches the abducent nerve within the cavernous sinus through the infratemporal fossa and the pterygoid plexus and its connecting emissary veins passing through the foramen ovale and lacerum.[8] Different manifestations observed following the administration of local anesthetic agents may be explained in terms of either sympathetic or parasympathetic involvement. the inferior orbital fissure transmits the maxillary nerve branch of trigeminal nerve, emissary veins connecting the inferior ophthalmic vein to pterygoid venous plexus, infraorbital vessels, zygomatic nerve and few twigs of pterygopalatine ganglion.

Question 94

Anesthetic treatment complication options for a patient with tongue paresthesia, causes (2) and management (2).

Answer 94

http://www.jcda.ca/article/c127 There are 3 main theories in the literature: needle trauma, intraneural hematoma and anesthetic toxicity. 1. Needle Trauma — Between 3% and 7% of our patients will feel an unpleasant “electric shock” on insertion of the needle. Studies and experience have shown that the vast majority of these contacts do not result in nerve damage as the tendency is for the needle to pass between the individual nerve fascicles. The lingual nerver can sometimes be unifasicular. Therefore it is more likely to be damaged by needle penetration than the IAN block. In addition, the lingual nerve tends to lie directly in the path of needle insertion for an inferior alveolar nerve block. 2. Intraneural Hematoma —the needle may pierce an intraneural blood vessel and cause a hematoma. --> compress the nerve fibres, causing reactive fibrosis and scar formation, thus applying further pressure to the nerve fibres. 3. Anesthetic Toxicity — The final and most controversial theory of nerve damage due to inferior alveolar nerve block is neurotoxicity of the local anesthetic solution. Haas and Lennon were the first to suggest that local anesthetic solutions have the potential for neurotoxicity, with articaine and prilocaine having a higher incidence because of their higher concentration. Possible mechanisms include intrafascicular injection and the production of aromatic alcohols in the vicinity of the nerve. Management: 85% of cases resolved within 8 on their own. If symptoms persist longer prognosis is poor. Patients presenting with hypoesthesia or persistent dysesthesia often require nerve microsurgery, optimally within 3 months. Refer to OMFS

Question 95

What effect does organic tissue have on sodium hypochlorite?

Answer 95

Inhibition (Haapasalo 2010)?

Question 96

What effect does epinephrine have on different adrenergic receptors?

Answer 96

Adrenaline or noradrenaline are receptor ligands to either α1, α2 or β-adrenergic receptors. α1 couples to Gq, which results in increased intracellular Ca2+ and subsequent smooth muscle contraction. α2, on the other hand, couples to Gi, which causes a decrease in neurotransmitter release, as well as a decrease of cAMP activity and a resulting and smooth muscle contraction. β receptors couple to Gs, and increases intracellular cAMP activity, resulting in e.g. heart muscle contraction, smooth muscle relaxation and glycogenolysis.

Question 97

ASA and ibuprofen use – according to AHA 2007 – rules for use of ibuprofen after low dose ASA. When can you give low dose ASA after Ibuprofen and vice versa?

Answer 97

ibuprofen can inhibit cardioprotective actions of ASA. ibuprofen should be taken at least 30 min after or at least 8 h before ASA

Question 98

What are some advantages to prescribing Pen VK for endo infections?

Answer 98

Effective in polymicrobial infections, narrow spectrum against most commonly found in endo infections, low toxicity and cost.

Question 99

What are ways that antibiotic resistance occurs?

Answer 99

Horizontal gene transfer (Conjugation, transduction, transformation) Vertical gene transfer (spontaneous mutation passed on through replication)

Question 100

What is a meta-analysis?

Answer 100

Methods contrasting and combining results from different studies, in the hope of identifying patterns among study results, sources of disagreement among those results, or other interesting relationships that may come to light in the context of multiple studies.

Question 101

What type of studies in Cochrane library?

Answer 101

is a collection of databases in medicine and other healthcare specialties provided by the Cochrane Collaboration and other organizations. At its core is the collection of Cochrane Reviews, a database of systematic reviews and meta-analyses which summarize and interpret the results of medical research.

Question 102

Ludwig’s angina, name the five spaces

Answer 102

There are five stages of biofilm development (see illustration at right):

Question 103

5 stages of biofilm development

Answer 103

1. Initial reversible attachment of free swimming micro-organisms to surface 2. Permanent chemical attachment, single layer, bugs begin making slime 3. Maturation 1 - Early vertical development 4. Maturation 2 - Multiple towers with channels between, maturing biofilm 5. Mature biofilm with seeding / dispersal of more free swimming micro-organisms

Question 104

name sources of stem cells

Answer 104

a) tooth germ progenitor cells (TGPCs) b) dental follicle stem cells (DFSCs) c) salivary gland stem cells (SGSCs), d) stem cells of the apical papilla (SCAP) e) dental pulp stem cells (DPSCs) f) stem cells from human exfoliated deciduous teeth (SHED) g) periodontal ligament stem cells (PDLSCs) h) bone marrow stem cells (BMSCs) i) and, as illustrated in the insert, oral epithelial stem cells (OESCs) and gingival-derived mesenchymal stem cells (GMSCs)

Question 105

MTAD contents and some BS

Answer 105

MTAD-doxycycline, citric acid, and a detergent (Tween 80). Pros: 1. reasonable antimicrobial property 2. better smear layer removal 3. lesser adverse effects on dentinal structure 4. better at promoting adhesion to dentin 5. good biocompatibility Cons: 1. less than optimal antimicrobial activity (Malkhassian G, 2009) 2. lesser compatibility to dental pulp cells for revascularization procedures 3. high cost 4. reduced shelf life

Question 106

QMix™ 2 in 1

Answer 106

solution contains a mixture of a bisbiguanide antimicrobial agent, a polyaminocarboxylic acid calcium-chelating agent, and a surfactant,

Question 107

What are bioceramics?

Answer 107

Bioceramics are ceramic materials specifically designed for use in medicine and dentistry. They include alumina and zirconia, bioactive glass, glass ceramics, coatings and composites, hydroxyapatite and resorbable calcium phosphates. They are interesting as sealers because: - high pH (12.8) - bactericidal - hydrophilic, not hydrophobic - enhanced biocompatibility - do not shrink or resorb (which is critical for a sealer-based technique) - they have excellent sealing ability - they set quickly - easy to use (particle size is so small it can be used in a syringe). Cons: - difficulty retreating. - ?

Question 108

1. Epithelial healing and CT healing – list 3 features of each and list 3 differences b/w them (table):

Answer 108

dont know

Question 109

2. List 2 features of osseous healing at Day 1, 14 and 28.

Answer 109

Day 1: a) Wound filled with coagulum containing disorganized, widey spaced fibrin strands b) Cortical and cancellous bone at wound edges appears devitalized Day 14: a) Endosteal tissue and multiple woven bone trabeculae occupy about 4/5 of wound b) Thick band of highly cellular, dense CT separates the wound from overlying flapped tissues Day 28: a) Maturing, new, and coalesced trabeculae in wound b) Fibers of delimiting membrane now have architecture similar to fibrous layer of the periosteum