Oral Health Group

Self Learning Assessment 2007 (September 01, 2007)

September 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.



NSAIDs are contraindicated for patients

1. taking digoxin.

2. taking methotrexate.

3. taking lithium.

4. with a history of gastrointestinal ulcer.

A. 1,2,3

B. 1 and 3

C. 2 and 4

D. 4 only

E. All of the above


Most of the serious side effects associated with NSAIDs come with Iong-term use rather than short-term application. NSAIDs do interact with angiotensin converting enzyme inhibitors, as well as with beta-blockers and diuretics, which make concomitant use inadvisable. Gastric mucosa and platelet aggregation are adversely affected by NSAIDs and the combined use of such drugs with anticoagulants can produce a significantly increased potential for bleeding. They should not be used for patients taking digoxin, methotrexate or lithium, or with a history of gastrointestinal ulcer.


1.Savage, M.G., Henny, M.A. Pre-operative non-steroidal anti-inflammatory agents: Review of the literature. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 98: 146-152, 2004.


Which of the following is the greatest cause of aerosol contamination in the dental office?

A. High speed drill

B. Water spray

C. Ultrasonic scaler

D. Air syringe


Aerosols and splatter are produced routinely during dental treatment and are highly contaminated with bacteria, viruses and blood components. Procedures that cause the most airborne contaminations involve power driven equipment, sprays or compressed air. The patient’s saliva, blood, subgingival fluids and nasopharyngeal matter form the most significant reservoir for potentially harmful micro-organisms.

The use of a rubber dam prevents contamination from sources other than the tooth, which should be minimal. When a rubber dam cannot be used, the high volume evacuator (HVE) can reduce airborne contamination by about 90%, but to be effective it requires a relatively large inside tip diameter of at least 6-8mm. The HVE is generally not used during dental hygiene procedures. Yet, the ultrasonic scaler is the greatest cause of aerosol contamination.

Therefore the HVE should always be used with the ultrasonic scaler.


1.Harrel,S.K.: Airborne spread of disease — the implications for dentistry. Calif Dent Assoc J 32:901-906,2004.


During the removal of bonded orthodontic brackets, the least enamel loss will result from the use of

1. slow speed tungsten carbide burs.

2. debanding pliers.

3. self-etching primer.

4. ultrasonic scaler.

A. 1, 2, 3

B. 1 and 3

C. 2 and 4

D. 4 only

E. All of the above


A study was designed to determine the effects on tooth enamel of removal of orthodontic brackets. Assessment of the enamel surface was made at each step of the process of bonding, debonding, and enamel cleanup after the use of a self-etching primer and compared with the values obtained with conventional etching and priming. The amount of enamel lost after conventional etching was significantly greater than that lost with the self-etching primer. It was also found that more bracket-adhesive failure occurred with the conventional technique as compared with the self-etching primer. In both groups, the high-speed tungsten carbide bur and the ultrasonic scaler caused the highest loss of enamel. Slow-speed tungsten carbide burs and debanding pliers resulted in the least enamel loss. However, more residual adhesive was present when the debanding pliers were used.


1.Hosein, I., Sheniff, M., Ireland, A.J.: Enamel loss during bonding, debonding and cleanup with the use of self-etching primer. Am J Orthod Dentofacial Orthop 126:717-724,2004.


Application of a 3% potassium oxalate gel to a tooth immediately following scaling and root planing is beneficial in reducing dentin hypersensitivity.

When applied topically after scaling and root planing, 3% potassium oxalate gel is effective initially in reducing dentin hypersensitivity, but its effect diminishes over the following weeks.

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.


In dentinal hypersensitivity (DH), the dentin is exposed resulting in a painful sensation after thermal, chemical, mechanical or osmotic stimulation. The pain is described as acute, localized, developing rapidly, and resolving quickly. The usual treatment for DH is the use of desensitizing toothpastes. Recently, the effect of a single topical application of a 3% potassium oxalate gel on teeth was investigated. Patients first underwent non-surgical scaling and root planing (SRP) under local anaesthesia. Using a split mouth design, 3% potassium oxalate gel or a placebo was applied to the cemento-enamel junction after SRP. A visual analog scale at baseline, 7, 14 and 21 days post SRP was used to measure DH reduction.

Seven days after treatment the percentage reduction in sensitivity for the potassium oxalate gel group was not statistically significant. Assessment at 14 and 21 days showed a progressive improvement in favour of the potassium oxalate gel group, which was statistically significant. Of the many ways of managing DH, it would seem that 3% potassium oxalate gel when applied topically after SRP, can provide beneficial results.


1.Pillon, F.L., Romani, I.G., Schmidt, E.R. Effect of a 3% potassium oxalate topical application on dentinal hypersensitivity after subgingival scaling and root planing. J. Periodontol 75: 1461-1464, 2004.

Answers to the August 2007 SLSA questions:

29. A

30. E

31. E

32. A

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