Oral Health Group
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Self learning, Self assessment 2010 (August 01, 2010)

August 1, 2010
by Oral Health


Question 29

Early failure of an implant is usually related to the surgery.

Late failure of an implant for a maxillary first bicuspid has prosthodontic occlusal overload implications.

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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

Implant failure can be broadly broken down into two – early and late. The former are usually associated with surgical procedures. Late failure is made manifest after osseointegration has occurred, for which occlusal overload is awarded the blame. A recent review provides guidelines for better management of implant bone prostheses to improve long term success. Kennedy Classes I, II and III are reviewed as well as the single tooth implant. Placement of an implant for the first maxillary bicuspid is often difficult because of lack of alveolar bone height and/or width. This requires occlusal loads to be small and directed in the long axis of the implant. Slight clearance is recommended between the implant’s occlusal surface and the opposing arch. Failure to leave occlusal clearance will subject the prosthesis to excessive load which the patient cannot feel because of a lack of periodontal ligament. In protrusive and lateral movements the occlusal surface of the implant should not be loaded and only natural teeth should participate in occlusal guidance.

Reference

1. Rilo, B., daSilva, J.L., Mora, M.J. et al. Guidelines for occlusion strategy in implant – borne prosthesis. A review. Int. Dent. J., 58 : 139 – 145, 2008.

Question 30

After orthodontic treatment the periodontium will show.

1. some alveolar bone loss.

2. gingival recession.

3. slight increase in pocket depth.

4. loss of attachment.

A. 1, 2, 3

B. 1 and 3

C. 2 and 4

D. 4 only

E. All of the above.

Rationale

For some time argument has been made that orthodontic therapy makes for easier cleaning, therefore less soft tissue irritation and improved periodontal health. A recent review refutes this claim. It indicates an absence of reliable evidence to show positive effects on periodontal health following orthodontic treatment. Comparison of orthodontic treatment versus no treatment involved 1,670 participants, 821 treated and 849 untreated. Results were as follows:

i. Pocket depth – 0.3 mm deeper in treated group

ii. Gingivitis – similar numbers of bleeding sites in both groups.

iii. Alveolar bone loss – 0.13 mm greater in treated group

iv. Gingival recession – .03 mm more gingival loss in treated group.

v. Attachment loss – slight increase of loss in treated group.

Claims that orthodontic treatment results in improved periodontal health therefore cannot be supported.

Reference

1. Bollen, A.M., Cunha-Cruz, J., Bakko, D.W. et al The effects of orthodontic therapy on periodontal health. JADA 139 : 413 – 422, 2008.

Question 31

To reduce post-operative discomfort potassium-dimethylisosorbide can be combined with

1. glass ionomer cement.

2. tooth whitening compounds.

3. cavity liners.

4. provisional cement.

A. 1, 2, 3

B. 1 and 3

C. 2 and 4

D. 4 only

E. All of the above.

Rationale

The discovery that depositing potassium-containing compounds, e.g. potassium nitrate (KNO3) around nerves in quantity can interfere with the nerves ability to initiate and conduct pain has led to new applications that have notably enhanced patient comfort. Now potassium-dimethylisosorbide is being combined with glass ionomer cements, tooth whitening compounds, cavity liners and provisional cements to manage postoperative pain. A gel with this substance has been developed for treating oral and/or dermatological ulcer pain which can also be used in deep scaling.

Reference

1. Hodosh, M., Hodosh, S.H and Hodosh, A.J. KNO3/benzocaine/tetracaine gel use for maintenance visit pain control. General Dentistry July/Aug, 312 – 315, 2007.

Question 32

The use of fluoride supplements during the first three years of life increases the risk of fluorosis.

There is little evidence that fluoride supplements after birth are of value in caries prevention of primary teeth.

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

A recent review of some major studies is reported on the use of fluoride supplements, caries experience and fluorosis. There was evidence that fluoride tablets given to school children were effective in caries prevention (probably a topical action). The use of supplements during the first 3 years of life increased the risk of fluorosis and the first year of life was the most important period for development of fluorosis. Supplements were found to be limited in value where caries incidence is low and where fluoridated dentifrices are being used regularly. There is little evidence that supplements are of value in caries prevention of primary teeth. However, in permanent teeth the effects are very positive.

Reference

1. Ismali, A.I. and Hasson, H. Fluoride supplements, dental caries and fluorosis – a systematic review. JADA 139 : 1457 – 1468, 2008.

Answers to the July 2010 SLSA questions:

25. E

26. C

27. E

28. E