Learning Assessment (June 01, 2001)

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, 2001 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

When considering orthodontic therapy for an adult, you should be aware that age-related biochemical changes can result in

1. decreased alveolar vascularity.

2. decreased collagen rigidity.

3. altered bone mineralization.

4. increased thickness of the periodontal ligament.

A. 1, 2, 3

B. 1 and 3

C. 2 and 4

D. 4 only

E. All of the above

Rationale:

Although there are age-related biochemical changes in the adult such as decreased alveolar vascularity, altered bone mineralization and increased collagen rigidity, these have not impeded orthodontic care. Indeed, studies have shown no difference in the duration of treatment when similar adult and adolescent problems are dealt with.

Brackets and bands make oral hygiene difficult. Bonded brackets rather than bands are indicated for adults. In addition, because of the higher crown height of adult teeth, there is less plaque accumulation and oral hygiene is easier.

Studies have shown that 65-75% of adults have some form of malocclusion which results in poor aesthetics, reduced masticatory function, occlusal trauma, and predisposition both to caries and periodontal disease.

Practitioners should also be aware that orthodontic tooth movement can be impeded by certain drugs used primarily by adults, especially prostaglandin inhibitors such as indomethacin prescribed for arthritis. Inhibitors of bone resorption used to treat osteoporosis, e.g., alendronate, can also impede tooth movement. Localized bone loss as a result of periodontal disease does not preclude orthodontic care, but it is essential that the inflammatory disease is controlled before treatment.

REFERENCE

Buttke, T.M, Proffit, W.R. Referring adult patients for orthodontic treatment. JADA 130:73-79, 1999.

QUESTION 22

In full crown preparation, which of the following would reduce the risk of postoperative pulpitis?

1. Incremental cutting of tooth substance.

2. A sharp high-speed bur.

3. A high-speed handpiece with a circumferential water spray.

4. An intra-periodontal ligament injection of local anaesthetic with a vasoconstrictor.

A. 1, 2, 3

B. 1 and 3

C. 2 and 4

D. 4 only

E. All of the above

Rationale:

It is established that post-operative pulpitis results from the release of a neuropeptide called substance P from sensory nerve endings. When an injection of local anaesthetic is made into the periodontal ligament, there is a considerable degree of vasoconstriction induced by the epinephrine. This leads to an almost ischemic condition of the pulp and during tooth preparation the neuropeptides are accumulated instead of being washed out from the pulp tissue. Pulpal damage occurs which leads to post-operative pulpitis. Clinical techniques must all aim at reducing the neuropeptide release. Therefore, kindness to tissues is necessary. Handpieces should provide coolant circumferentially to the tooth and use of sharp burs, along with small incremental reduction of dentin, are essential. These actions will control heat build-up and reduce the amount of neuropeptide release.

REFERENCES

1.Zhang, C., Banting, D.W., Gelb, A.W., et al. Effect of ?-adrenoreceptor blockade with nadolol on the duration of local anaesthesia. JADA 130:1773-1780. 1999.

2.Kim, S., Dorscher-Kim, J., Liu, M.T., et al. Biphasic pulp blood response to substance P in the dog as measured with radiolabelled microsphere injection method. Arch Oral Biol 33:305-309. 1988.

QUESTION 23

The Periochip is

1. applied locally.

2. useful in care of deep pockets.

3. reduces the need for surgical intervention.

4. a cost-effective antibiotic.

A. 1, 2, 3

B. 1 and 3

C. 2 and 4

D. 4 only

E. All of the above

Rationale:

The Periochip relies on release over time of chlorhexidine in a local site. As it is not an antibiotic, resistant strains of microoorganisms will not develop. It has the benefit of easy application. It has recently been shown not only to be an effective treatment, but also to be highly cost-effective. In disease management, it may be used as an adjunct to scaling and root planing, or in maintenance therapy of deep pockets, thereby avoiding a surgical procedure. Such a regimen calls for placing the Periochip in deep pockets over 5 mm every three months.

REFERENCES:

1.Finkelman, R.D. and Williams, R.C. Local delivery of chemotherapeutic agents in periodontal therapy: Has it arrived? J Clin Periodontol 25:943-946, 1998.

2.De Lissovoy, G., Rentz, A.M., Dukes, E.M., et al. The cost-effectiveness of a new chlorhexidine delivery system in the treatment of adult periodontitis. JADA 130:855-862, 1999.

QUESTION 24

In the management of a patient with root caries, you would

1. prescribe toothpaste containing fluoride.

2. counsel the patient on improved oral hygiene of the root surfaces.

3. provide carbohydrate dietary instruction.

4. evaluate drug usage by the patient.

A. 1, 2, 3

B. 1 and 3

C. 2 and 4

D. 4 only

E. All of the above

Rationale:

Root caries is a localized destruction of dentin and cementum, which is caused by microorganisms. The lesions can be found at the cemento-enamel junction or are confined entirely to the exposed root surface. As with coronal caries, the three main factors of host, microflora, and diet have to be present and interact. However, the following increase root caries risk: newly exposed root surfaces, low salivary secretion rate, high counts of lactobacilli and Streptococci mutans, frequent intake of fermentable carbohydrates, high plaque index and low exposure to fluorides.

Salivary secretion decreases with advancing age, and many drugs prescribed for the elderly to manage medical problems cause xerostomia. As gingival recession in the elderly results in more exposed root surfaces, poor oral hygiene in this older population can result in increased root caries.

A recent study has demonstrated that, in the elderly, coronal caries is associated with higher levels of S. mutans, whereas lactobacilli are found in higher numbers in root surface caries. Several studies have shown that the incidence rate of caries, both coronal and root forms, increases with age. For example, root caries incidence in 45-65 year-olds is 32%, 65-75 years 43%, and 75+ years 47.8%

REFERENCES

1.Loesche, W.J., Taylor, G.W., Dominguez, L.D. et al. Factors which are associated with dental decay in the older individual. Gerontology 16:37-46, 1999.

2.Ettinger, R.L., Mulligan, R. The future of dental care for the elderly population. J Calif Dent Assoc 27:687-692, 1999.

Answers for May 2001 SLSA questions:

17. E 18. C 19. A 20. C

Funding for the SLSA program has been provided by:

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