2004 Self Learning Assessment (April 01, 2004)

The SLSA Program is based on a series of questions, answers, rationales and references followed by an annual 15-question quiz. All material is from current referenced literature. Completion of the quiz leads to CE points. Names and license numbers of dentists are forwarded to the appropriate licensing authorities.

QUESTION 13

A woman who is eight months pregnant requires analgesia for moderate to severe postoperative pain following a dental extraction. Which of the following would you prescribe?

A. Acetaminophen 1000 mg q 4 h.

B. Acetaminophen 1000 mg q 6 h.

C. Acetylsalicylic acid 650 mg q 6 h.

D. Ibuprofen 400 mg q 4 to 6 h.

Rationale

Acetaminophen is the drug of choice in all stages of pregnancy. It provides effective analgesia in doses of 500 to 1000 mg q 4 to 6 h, but the total daily dose should not exceed 4000 mg. The use of NSAIDs, including acetylsalicylic acid (ASA) is contraindicated in the third trimester of pregnancy, as they may predispose to ineffective contractions during labour, increased bleeding during delivery and premature closure of the ductus arteriosus.

If acetaminophen is insufficient, opioids may be used in conjunction, provided they are given only for short periods of time. Chronic use of opioids during pregnancy can result in foetal dependence, premature delivery and growth retardation.

As with pregnancy, acetaminophen is the analgesic of choice for the lactating mother. Opioids may also be used. ASA should be avoided.

The dentist must be mindful that analgesics are the second best means of managing pain. The best means is to remove the cause as quickly as possible.

REFERENCE

1.Haas, D.A. An update on analgesics for the management of acute postoperative dental pain. J Can Dent Assoc, 8:476-482. 2002.

QUESTION 14

Patients receiving chemotherapy may develop which of the following oral problems?

1. Atrophic thinning of the mucosa.

2. Ulceration.

3. Pain.

4. Spontaneous bleeding.

A. 1, 2, 3

B. 1 and 3

C. 2 and 4

D. 4 only

E. All of the above

Rationale

Forty percent of patients receiving chemotherapy will develop significant oral problems. The stomatotoxicity of the agent can be divided into direct and indirect effects. Oral mucosal cells undergo rapid renewal and a chemotherapy agent may cause a reduction in the renewal rate with consequent mucosal atrophy and ulceration. This is one example of direct stomatotoxicity. Clinically, patients experience severe pain and difficulty in swallowing from the ulceration, which generally occurs on the non-keratinized surfaces of the mucosa. Symptomatic treatment using viscous lidocaine and coating agents give some relief. Indirect stomatotoxicity is best exemplified by the effect seen on bone marrow cells, which can result in granulocytopenia and thrombocytopenia. The granulocytopenia opens the way to opportunistic infection, which in the mouth can be bacterial, fungal, viral or mixed. The thrombocytopenia can lead to bleeding because of platelet reduction. Patients may be given a granulocyte “colony stimulating” factor to reduce the duration and extent of the oral problems. Xerostomia is a major problem interfering with speech and swallowing, as well as oral hygiene. Patients should be encouraged to use artificial saliva products. They also must maintain as good oral hygiene as possible. A soft brush is recommended, but if brushing is difficult, a soft sponge or gauze may be used to assist in cleaning. Chlorhexidine gluconate mouthwash can also be recommended but, if the alcohol content in it causes too much discomfort, salt or baking soda in water can be useful alternatives.

REFERENCES

1.Ord, R.A., Blanshaert, R.H. Current management of oral cancer. A multidisciplinary approach. JADA 132:19S-29s. 2001.

2.Sung, E.C. Dental management of patients undergoing chemotherapy. CDA Journal 23:55-59, 1995.

QUESTION 15

Problems associated with cervical lesions of teeth are

1. aesthetics.

2. hypersensitivity.

3. caries.

4. gingival recession.

A. 1, 2, 3

B. 1 and 3

C. 2 and 4

D. 4 only

E. All of the above

Rationale

Poor aesthetics is related to all cervical lesions at the front of the mouth. In many cases gingival recession is the precursor through which cementum of the root is exposed. Mechanical abrasion exposes dentine and because of open tubules hypersensitivity develops. However, hypersensitivity is also seen after removal of enamel by non-bacterial acids-the erosion cavity. It is created by a combination of acid action and mechanical abrasion. The effect of acid on enamel and dentine is enhanced when salivary flow decreases as in the elderly. This carious cervical lesion varies in size, shape, and depth. Mechanical abrasion alone will produce a lesion which is typically V or wedge-shaped with a sharp edge. This non-carious lesion has been termed “abfraction.”

A recent study investigated the use of four tooth-coloured direct restorative materials for cervical cavities. These were glass ionomer cements, resin-modified glass ionomer cements, composite resins and compomers (polyacid-modified composite resin). Selection of the material was made according to the type of lesion. Results indicated that in caries active dentitions fluoride releasing glass ionomer cement or resin-modified glass ionomer should be used. Erosion and abrasion lesions require acid and wear-resistant materials such as composite resins. Although compomers can also be used, they are particularly recommended for V shaped abfractions since they have a low modulus of elasticity, allowing them to bend with the tooth under functional loading and this lessens the risk of displacement.

REFERENCE

1.Blunck, V. Improving cervical restorations: A review of materials and techniques. J Adhesive Dent. 3:33-44. 2001.

QUESTION 16

After a local anaesthetic injection of 2cc of 2% lidocaine with 1:100,000 epinephrine in a patient with mild to moderate heart disease, you would expect

A. no change in the heart rate.

B. an increase in the heart rate.

C. a rise in the blood pressure.

D. a drop in the blood pressure.

Rationale

Human studies on the hemodynamic variables after a dental injection of 1.8 to 5.4 ml of 2% lidocaine with 1:100,000 epinephrine have found no significant changes in mean arterial blood pressure or heart rate in healthy patients or in those with mild to moderate cardiovascular disease. It is therefore suggested that those with mild to moderate cardiovascular disease are given the smallest amount of local anaesthetic with vasoconstrictor needed for profound anaesthesia. It is further suggested that use of conscious sedation on such patients is beneficial in stress reduction and should be considered.

Normal epinephrine release from the adrenal medulla can increase 20-40 fold during stress. Such stress may be induced by pain during dental treatment. A patient having a local anaesthetic without a vasoconstrictor frequently has impaired pain control compared to an injection of local anaesthetic with epinephrine. Thus, a patient with cardiovascular disease may be at greater risk when the dentist uses an epinephrine-free local anaesthetic because of stress-released endogenous epinephrine.

REFERENCE

1.Glick, M. Screening for traditional risk factors for cardiovascular disease. JADA 133:291-300. 2002.

Answers to March 2004 SLSA Quiz

9. A

10. C

11. C

12. D

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