Self Learning Assessment 2005 (June 01, 2005)

The SLSA program is based on current, referenced literature and consists of 40 questions, answers, rationales and references. Answers appear at the end of each quiz.

Dentists who complete the 15 question quiz in the November, 2005 issue of Oral Health may be eligible to receive continuing education points. The names and license numbers of all who complete the quiz will be forwarded to their respective provincial licensing authorities.

QUESTION 21

In dentin hypersensitivity, tubules must be open to the oral cavity and the pulp.

Dentin hypersensitivity is diagnosed by exclusion of other factors.

A. The first statement is true, the second is false.

B. The first statement is false, the second is true.

C. Both statements are true.

D. Both statements are false.

Rationale

Two processes are essential for the development of dentin hypersensitivity. Dentin must become exposed and the dentin tubules must be open to both the oral cavity and the pulp. Dentin hypersensitivity is characterized by short, sharp pain arising from exposed dentin in response to stimuli typically thermal, evaporative, tactile, osmotic or chemical, which cannot be ascribed to any other form of dental defect or disease. The diagnosis of dentin hypersensitivity is one of exclusion. Erosion, abrasion, attrition and possibly abfraction lead to exposure of tubules. Gingival recession (a predisposing factor) is not a cause by itself. Neither bruxism nor malocclusion has been identified as a causative factor. A study of a representative sample of the Canadian population found that the incidence of hypersensitivity is about 30 percent in adults aged 18 to 64. The most widely accepted mechanism of dentin hypersensitivity is the hydrodynamic theory proposed by Brnnstrm, whereby fluid flow within the tubules is altered by various stimuli near the exposed surface of the tubules, which leads to stimulation of certain fibres surrounding the odontoblasts. It should be noted that reversible procedures should be used before non-reversible. In the initial management of dentin hypersensitivity predisposing factors and causes should be removed or modified and desensitizing toothpastes should be used daily as the first approach.

REFERENCE

1.Holland, G.R., Narhi, M.N., Addy, M. et al. Guidelines for the design and conduct of clinical trials on dentine hypersensitivity, J Clin Periodontol, 24:808-813, 1997.

2.Canadian Advisory Board on Dentin Hypersensitivity. Consensus-based recommendations for the diagnosis and management of dentin hypersensitivity. J Can Dent Assoc. 69:221-226, 2003.

QUESTION 22

In the elderly, chronic use of systemic corticosteroids can lead to an increase of anaerobic organisms in the saliva.

Long-term use of systemic and inhaled corticosteroids predisposes to oral candidiasis.

A. The first statement is true, the second is false.

B. The first statement is false, the second is true.

C. Both statements are true.

D. Both statements are false.

Rationale

Chronic use of systemic and inhaled corticosteroids predisposes patients to microbial infections of which oral candidiasis is high on the list. In the older patient, frequently with poorer oral hygiene there is an increase in the anaerobic organisms of the gingival crevice and the saliva. From this source and frequent swallowing dysfunction as a result of debilitation or medication, there is an increased risk of aspiration pneumonia. Patients at risk require routine dental examinations and treatment.

REFERENCES

1.Seymour, R.A. Dentistry and the medically compromised patient. Surg J R Coll Surg Edinb. 1.207-214, 2003.

2.Ship, J.A., and Chavez, E.M. Management of systemic diseases and chronic impairments in older adults: Oral health considerations. General Dentistry. Sept/Oct. 555-565, 2000.

QUESTION 23

A patient presents with acute apical periodontitis. You would

1. initiate root canal therapy.

2. prescribe antibiotics.

3. relieve hyperocclusion.

4. trephine the area to relieve pressure.

A. 1, 2, 3

B. 1 and 3

C. 2 and 4

D. 4 only

E. All of the above

Rationale

Acute apical periodontitis (AAP) is a periapical inflammation resulting from an untreated, non-vital pulp. Features of AAP are constant pain, which has occurred over a short period of time with marked pain to biting or percussion of the associated tooth. Rarely is there sensitivity of the tooth to thermal changes. There is a delayed or negative response to vitality tests and no radiographic bony changes are seen, although there may be some evidence of widening of the periodontal ligament space. Swelling, periapical radiolucency and systemic changes are not associated with AAP.

A review of the literature has provided the basis for practice guidelines and the recommendations are:

* Root canal therapy should be started as soon as possible.

* Analgesics (NSAIDs if not contraindicated) should be given preoperatively, or immediately post-operatively and continued as needed.

* If root canal therapy cannot be started immediately, appropriate analgesics should be prescribed.

* Extraction may be an alternative to endodontic therapy for some patients.

* If the tooth is in hyperocclusion, it should be relieved if possible.

Antibiotic therapy and bony trephination are not indicated for this condition.

REFERENCE

Sutherland, S., Mathews, D.C. Emergency management of acute apical periodontitis in the permanent dentition: A systematic review of the literature. J Can Dent Assoc. 69:160-161, 2003.

QUESTION 24

Which of the following agents is/are capable of penetrating the extracellular matrix that protects microorganisms in plaque biofilm?

1. Cetylpyridinium chloride

2. Triclosan

3. Essential oils

4. Chlorhexidine

A. 1, 2, 3

B. 1 and 3

C. 2 and 4

D. 4 only

E. All of the above

Rationale

Dental plaques are now recognized as organized microbial biofilm communities. In these biofilms, the organisms are protected by an extracellular matrix, which must be penetrated by the antimicrobial agent to be effective. Agents with this ability are chlorhexidine, Triclosan, cetylpyridinium chloride and a fixed combination of essential oils. These are found in both toothpastes and mouthwashes.

Repeated removal of supragingival plaque affects the subgingival plaque biofilm by altering the subgingival microflora along with which there is a reduction in pocket depth. Removal of supragingival plaque has at least three benefits:

* A decrease in the reservoir for colonisation by periodontal pathogens.

* A reduction of gingival inflammation with decrease in damage to adjacent connective tissues of the periodontium.

* Alteration in the composition and numbers of subgingival microorganisms, which in part occurs as a result of decreased flow of gingival crevice fluid needed for growth of subgingival plaque.

REFERENCES

1.Barnett, M.L. The role of therapeutic antimicrobial mouthrinses in clinical practice-control of supragingival plaque and gingivitis. JADA 134:699-704. 2003.

2.Banroth, K., Charles, C.M., Mancodi, S.M. et al. The efficacy of an essential oil antiseptic mouthrinse vs. dental floss in controlling interproximal gingivitis. JADA. 134:359-365. 2003.

Answers to the May 2005 SLSA Questions

17. E

18. D

19. E

20. C

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