2003 Self Learning Assessment (January 01, 2003)

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, 2002 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 1

A pin-retained amalgam replacing a cusp in a molar tooth will function better than a bonded amalgam.

A bonded amalgam will demonstrate less tooth sensitivity than a pin-retained amalgam.

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 study examined the restoration of functional but badly broken down posterior teeth in which cusp and proximal replacements were part of the selection criteria. Sixty teeth were selected and randomly allocated for either treatment. One half of the study teeth was restored with a self-threaded pin-retained amalgam and the other half with bonded amalgam.

At the time of five-year recall statistical analysis failed to show any significant difference between the two treatment methods for marginal adaptation, marginal discolouration, secondary caries, sensitivity or tooth vitality. In a functional sense too, bonded restorations performed as well as pin-retained amalgams.

REFERENCE

1.Summitt, J.B., Burgess, J.O., Berry, T.G. et al. The performance of bonded vs. pin-retained complex amalgam restorations-a five-year clinical evaluation. JADA 132:923-931. 2001.

QUESTION 2

In examining patients using a periodontal probe, which of the following is/are factors that contribute to bacteraemia?

1.Age.

2.Bleeding on probing.

3.Number of teeth probed.

4.Periodontitis.

A.1, 2, 3D.4 only

B.1 and 3E.All of the above

C.2 and 4

Rationale

A recent study reported that neither age nor the number of teeth probed were contributors to bacteraemia. However, the extent of bleeding on probing and the probing depth per tooth were associated with positive bacteraemias. Patients with untreated adult periodontitis were at greater risk to bacteraemia due to periodontal probing than those with chronic gingivitis. A major predictor of bacteraemia due to probing was the presence of interproximal bone loss as seen from radiographs.

Although studies have shown that smokers exhibit less gingival bleeding on probing than non-smokers, there was no evidence that smokers would experience less of a bacteraemia than non-smokers.

As a means of preventing bacteraemia, especially in patients at risk for infective endocarditis and other heart ailments, an important finding of the study points to the use of a radiographic assessment of patients to detect the presence of active bone loss and periodontitis before periodontal probing. In such patients, appropriate antibiotic coverage is essential before probing, as detailed in the rationale of question 3.

REFERENCE

1.Daly, C.G., Mitchell, D.H., Highfield, J.E. et al. Bacteraemia due to periodontal probing: a clinical and microbiological investigation. J Periodontol 72:210-214. 2001.

QUESTION 3

What is the recommended prophylactic antibiotic regimen for prevention of infective endocarditis in an adult patient who is not allergic to penicillin?

A.Cefazolin 1g intramuscularly (IM) or intravenously (IV) within 30 minutes of procedure.

B.Clindamycin 600mg orally one hour before procedure.

C.Amoxicillin 2g orally one hour before procedure.

D.Amoxicillin 2g orally one hour before procedure and amoxicillin 1 g orally 6 hours later.

E.Azithromycin 500mg orally one hour before procedure.

Rationale

For patients not allergic to penicillin, the recommended drug for prophylactic coverage is amoxicillin. The now recommended dose is 2 g orally one hour before the procedure. It has been reported that 2 g of amoxicillin provides several hours of coverage, and no follow-up dose is required.

The following table lists antibiotic prophylactic regimens for various situations in adults, as recommended by the American Heart Association (2000), but practitioners should be aware that guidelines change periodically.

ANTIBIOTIC PROPHYLACTIC REGIMENS

Situation	Antibiotic	Regimen
Standard prophylaxis	Amoxicillin	2.0g p.o. one hour before procedure
Cannot use oral medications	Ampicillin	2.0g IM or IV within 30 minutes of procedure
Allergic to penicillin	Clindamycin	600mg p.o. one hour before procedure
	Cephalexin* or cefadroxil*	2.0g p.o. one hour before procedure
	Azithromycin or clarithromycin	500mg p.o. one hour before procedure
Allergic to penicillin and unable to take oral medications	Clindamycin	600mg IV one hour before procedure
	Cefazolin*	1.0g IM or IV within 30 minutes of procedure

*Cephalosporins should not be used in patients with immediate-type hypersensitivity reaction (urticaria, angioedema, or anaphylaxis) to penicillins.

REFERENCE

1.Tong, D.C., Rothwell, B.R. Antibiotic prophylaxis in dentistry: a review and practice recommendations. JADA 131:366-374. 2000.

QUESTION 4

The subepithelial connective tissue graft for management of gingival recession, when compared to the free gingival graft,

1.leads to less predictable root coverage.

2.is a more traumatic surgical procedure.

3.has more severe postoperative complications.

4.results in a better aesthetic outcome.

A.1, 2, 3D.4 only

B.1 and 3E.All of the above

C.2 and 4

Rationale

The most widely used surgical procedure for management of gingival recession is the subepithelial connective tissue graft because of its high predictability in achieving root coverage. The surgery is less traumatic than the free gingival graft and has fewer and less severe postoperative complications. It results in a better aesthetic outcome, allowing superior tissue colour match.

Miller introduced the following classification of gingival recession:

Class 1–Marginal tissue recession with no extension to the mucogingival junction. No periodontal loss in the interdental area.

Class 2–Marginal tissue recession with extension to or beyond the mucogingival junction. No periodontal loss in the interdental area.

Class 3–Marginal tissue recession with extension to or beyond the mucogingival junction. Bone or soft tissue loss in the interdental area is present or there is malposition of teeth.

Class 4–Marginal tissue recession with extension to or beyond the mucogingival junction. Severe bone or soft tissue loss in the interdental area or severe malposition of teeth.

The clinician can anticipate full root coverage in Class 1 and Class 2 cases, partial coverage in Class 3 cases, and very little or no coverage in Class 4 cases.

REFERENCE

1.Leve, R. The subepithelial connective tissue graft. Oral Health 54-60. May 2001.

SLSA 2002 QUIZ ANSWERS

1. C

2. A

3. B

4. E

5. C

6. B

7. C

8. B

9. E