2004 Self Learning Assessment (January 01, 2004)

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, 2004 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 1

A patient who is a moderate asthmatic should be given an early morning appointment for a molar tooth extraction.

For an asthmatic patient, the analgesic of choice for the management of postoperative pain is acetaminophen.

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

Anxiety is a known cause of asthmatic attacks and the dental office environment commonly causes anxiety. For a moderate asthmatic patient, it must be ascertained that a recent dose of antiasthma medication has been taken before treatment and appointments should be made for late morning or early afternoon. During dental treatment, the most likely time for an acute attack is during or immediately after local anaesthetic administration. This is especially so with anaesthetic solutions which contain sodium metabisulphite, a preservative which is highly allergenic. Procedures such as tooth extraction, surgery or pulp extirpation are also conducive to causing reaction asthma.

In post treatment control of pain, it must be noted that up to 20% of asthma patients react with severe bronchoconstriction after ingesting aspirin and other nonsteroidal anti-inflammatory drugs (NSAIDs). Ketorolac, ibuprofen and naproxen sodium are all offenders, along with aspirin, and must be avoided because of possible allergic reaction. The analgesic of choice for these patients is acetaminophen.

REFERENCE

1.Steinbacher, D.M., Glick, M. The dental patient with asthma. An update and oral health considerations. JADA 132:1229-1239. 2001.

QUESTION 2

Which of the following are clinical properties of resin-modified glass ionomer cements?

1. Coefficient of expansion equivalent to tooth substance.

2. Inhibition of secondary caries.

3. Physicochemical bonding to tooth substance.

4. Resistance to wear.

A. 1, 2, 3D. 4 only

B. 1 and 3E. All of the above

C. 2 and 4

Rationale

All glass ionomer systems have a coefficient of expansion similar to that of natural tooth structure and have a physicochemical bond to enamel and dentine. The original glass ionomer cements had poor properties of compressive strength and wear resistance. The newer resin-modified glass ionomer cements show improved wear resistance and compressive strength.

A recent study examined resin-modified glass ionomer cements as restorations for primary teeth in a retrospective manner over at least a three-year period. Restorations were assessed in Classes I, II, III, and V preparations in which evaluation was based on wear, marginal integrity, axial contour and secondary caries. The success rates were as follows:

Class III restorations15 out of 15(100.0%)

Class V restorations 49 out of 50(98.0%)

Class II restorations 379 out of 406(93.3%)

Class I restorations 364 out of 393(92.6%)

Most of the failures of Class I and Class II restorations were due to wear. Only 0.1% (1 out of 864) failed as a result of secondary caries. The findings in this retrospective study indicate that resin-modified glass ionomer cement is an effective restorative material for Classes I, II, III and V restorations in primary teeth.

REFERENCE

1.Croll, T.P., Bar-Zion, Y., Segura, A. et al. Clinical performance of resin-modified glass ionomer cement restorations in primary teeth. A retrospective evaluation. JADA 132:1110-1116. 2001.

QUESTION 3

Biofilms in dental waterlines form when “free” bacteria settle on solid surfaces as a result of

1. gravity.

2. electrostatic attraction.

3. movement of motile organisms to adsorbed nutrients.

4. colonization with the production of exopolysaccharides.

A. 1, 2, 3

B. 1 and 3

C. 2 and 4

D. 4 only

E. All of the above

Rationale

The term biofilm was introduced in 1978 to describe a complex community of bacteria. Rather than a random collection, biofilms exhibit a complex level of organization, which is more in keeping with the structure of multi-cellular organisms. Biofilms form when planktonic (free floating) bacteria settle on solid surfaces as a result of gravity, electrostatic attraction or movement of motile organisms to adsorbed nutrients. Some bacteria act as primary colonizers and, by producing long chain exopolysaccharides, form a slime matrix. The change from planktonic to sessile existence marks dramatic phenotype changes in the bacteria, with growth of some types and suppression of others. Although bacteria are primary colonizers, over time fungi, algae, protozoa and others are recruited to the matrix.

Modern dental units provide an environment suitable for the growth of aquatic biofilm. This can contribute to the contamination of the water lines with microorganisms and endotoxins. Untreated dental units will fail to meet national water standards. Little epidemiological evidence exists that biofilm in dental units has resulted in widespread illness. The problem clinically is realized when treating the immunocompromised. For such patients, any work involved in cutting of bone should utilize sterile water systems for the equipment involved.

Continuous and intermittent chemical treatment with chlorine and iodine compounds, chlorhexidine gluconate, hydrogen peroxide and other agents have shown improved water quality. Filtration, too, is effective in trapping microbes, but it has no effect on biofilms or endotoxins.

REFERENCES

1.Mills, S.E., and Karpay, R.I. Dental waterlines and biofilm . Searching for solutions. Compendium 23:237-256. 2002.

2.Linger, J., Molinari, J.A., Forbes, W.C., et al. Evaluation of a hydrogen peroxide disinfectant for dental unit waterlines. JADA 132:1287-1291. 2001.

QUESTION 4

Osteoporosis is a condition which

1. is asymptomatic initially.

2. predisposes to fracture of skeletal bones.

3. accelerates ridge resorption in the edentulous mouth.

4. causes loss of teeth because of periodontal disease.

A. 1, 2, 3

B. 1 and 3

C. 2 and 4

D. 4 only

E. All of the above

Rationale

Osteoporosis is characterized by low bone mass and deterioration of the bone architecture leading to increased bone fragility and fracture. It is referred to as the “silent disease”-symptomless early and occurring most frequently but not exclusively in post-menopausal women. Improved diagnostic methods have shown that oral bone loss accompanies osteoporosis to cause ridge resorption and alveolar bone height reduction with subsequent tooth loss.

Recent work has identified osteoporosis as a risk factor for periodontitis. Alveolar bone loss is related to the overall decrease in skeletal bone mineral density. This may be due to several factors. It may be that since alveolar bone around teeth is less dense, it has less resistance to resorption. Genetic and local factors, too, must be taken into account.

Efforts to prevent oral bone loss are directed at plaque control and, where suspected, referral of patients for appropriate systemic management with estrogen replacement therapy and calcium supplementation if indicated. A patient with osteoporosis who is edentulous requires careful and frequent scrutiny by the dentist to check that dentures fit and occlusion is satisfactory to prevent accelerated ridge resorption.

REFERENCES

1.Krejci, C.B., and Bissada, N.F. Women’s health issues and their relationship to periodontitis. JADA 133:323-328. 2002.

2.Jeffcoat, M.K., Lewis, C.E., Reddy, M.S., et al. Postmenopausal bone loss and its relationship to oral bone loss. Periodontol 2000. 23:94-102. 2000.

SLSA 2003 QUIZ ANSWERS

1. E

2. A

3. E

4. C

5. C

6. B

7. E

8. C

9. C

10. E

11. E

12.
C

13. C

14. D

15. A

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