Oral Health Group
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Self Learning Assessment 2007 (August 01, 2007)

August 1, 2007
by Oral Health


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

Dentists who complete the 15 question quiz in the November, 2007 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.

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QUESTION 29

The application of a pack heated to 55C can improve blood flow in the muscle tissue if applied to the overlying skin

A. for 20 minutes, followed by a rest period of 20 minutes and repeated.

B. for 1 hour, followed by a rest period of 1 hour and repeated.

C. for 2 hours, followed by a rest period of 1 hour and repeated.

D. as continuously as possible.

Rationale

Although it was always thought that the application of heat caused vasodilation and increased blood flow in deeper structures, it has been very difficult to prove. Recently non-invasive procedures have been developed which allow for measurement of total haemoglobin volume, deoxygenated haemoglobin volume, oxygenated haemoglobin volume and oxygen saturation levels. Using the masseter muscle, a study was conducted in two groups, one with the application of a hot pack heated to 55C and a control group with a sham application pack heated to 37C. Results showed that the blood flow only increased in the group with a hot pack heated to 55C. Total haemoglobin volume, oxygenated haemoglobin volume and oxygen saturation levels all increased significantly compared to the control group and the deoxygenated haemoglobin volume decreased significantly.

In temporomandibular disorders muscle pain due to fatigue is thought to be caused by a decrease in intramuscular blood flow. Therefore treatments that can improve blood flow are thought to be effective. Similarly in the management of infections, intraoral use of heat can help the resolution of the process by improving blood flow and bringing in the body’s defense mechanisms. As continuous heating may induce sweating and consequently vasoconstriction, local application of heat as therapy should be limited to 20 minute intervals.

REFERENCE

Okada, K., Yamaguchi, T., Minowa, K. et al: The influence of hot pack therapy on the blood flow in the masseter muscle. Journal of Oral Rehabilitation 32:480-486, 2005.

QUESTION 30

In treatment of dentin hypersensitivity, Gluma Desensitizer

1. contains gluteraldehyde.

2. causes blockage of dentinal tubules.

3. precipitates tubular protein to a depth of 50 microns.

4. will provide relief for up to 9 months.

A. 1, 2, 3

B. 1 and 3

C. 2 and 4

D. 4 only

E. All of the above

Rationale

Dentin hypersensitivity manifests as a short, sharp pain induced by thermal, tactile, chemical or air evaporative stimuli. Sensitive teeth have widely exposed dentin tubules and pain is attributed to the Brnnstrom hydrodynamic theory of dentinal fluid movement. A treatment concept of tubular occlusion is therefore logical. Gels and varnishes with stannous or sodium fluoride and dentifrices with strontium chloride are effective in the short term. A recent study looked at long term effects of Gluma Desensitiser and found that it was effective in sensitivity relief for at least 9 months after treatment. The gluteraldehyde content of the desensitizer precipitates the protein in the dentin tubules to a depth of 50 microns.

REFERENCE

Kakaboura, A., Rahiotis, C., Thomaidis, S., et el. Clinical effectiveness of two agents on the treatment of cervical sensitivity. Am J Dent 18:291- 295, 2005.

QUESTION 31

As a post -core material a resin-based composite

1. has acceptable esthetics.

2. has good strength.

3. has low solubility.

4. shrinks during polymerisation.

A. 1, 2, 3

B. 1 and 3

C. 2 and 4

D. 4 only

E. All of the above

Rationale

A post should only be used when there is insufficient tooth substance left for a final restoration, the function of the post being to retain a core for a coronal restoration. The most common core materials in current use are cast gold, amalgam, resin-based composite and glass ionomer cement. Gold and amalgam have high strength, low solubility and a coefficient of expansion similar to tooth substance. However, gold and amalgam are not esthetically pleasing especially for anterior tooth restorations. Resin based composite provides for this esthetic need and it has good strength and low solubility. However, polymerization shrinkage and incompatibility with ZOE in many root canal sealers can cause difficulties. Removal of residual sealer and incremental core build up using a condensable resin based composite can alleviate the problem.

REFERENCES

1. Cheung, W.: A review of the management of endodontically treated teeth. JADA136:611-619,2005

2. Fernandes, A.S., Sharat, S., Continho, I.: Factors determining post selection: A literature review. J Prosthet Dent. 90:556-562, 2003.

QUESTION 32

In a patient with a previous history of stroke, which of the following is predictive of recurrent stroke?

A. Elevated IgA antibody levels to P. gingivalis.

B. Elevated serum IgA antibody levels to A. actinomycetemcomitans.

C. A combination of elevated serum IgA levels to both P. gingivalis and A.actinomycetemcomitans.

D. None of the above.

Rationale

Periodontitis produces pathological periodontal pockets where bacterial infection persists and causes chronic inflammation serving as a reservoir for predominantly gram-negative bacteria. Although periodontitis is a potential risk factor for coronary heart disease, it has not been extensively evaluated in relation to cerebrovascular events (stroke). An investigation of 6,950 subjects over 13 years looked at whether elevated serum antibody levels to major periodontal pathogens were linked to stroke. For each case, two controls were matched for gender, age, municipality and disease status. The results of the study showed that chronic infection with A. actinomycetemcomitans and P. gingivalis is associated with an increased incidence of future stroke. Elevated serum IgA class antibody levels to A. actinomycetemcomitans were predictive of stroke. Elevated serum IgA class antibody levels to P. gingivalis were predictive of recurrent stroke among patients who had a previous history of stroke or coronary heart disease.

REFERENCE

Pussinen, P.J., AIfthan, G., Rissanen, H. et al: Antibodies to periodontal pathogens and stroke risk. Stroke 35:2020-2023, 2004.

Answers to the July 2007 SLSA questions:

25. E

26. E

27. C

28. C


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