Self Learning Assessment 2007 (June 01, 2007)

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.


Established periodontitis in a pregnant woman can

1. increase the level of interleukin (IL)- 6 in the amniotic fluid.

2. increase the level of prostaglandin-E2 (PGE2) in the amniotic fluid.

3. affect the primary host response.

4. show periodontitis bacteria in the amniotic fluid.

A. 1, 2,3

B. 1 and 3

C. 2 and 4

D. 4 only

E. All of the above


A study of 36 women found 83% of cases with pre-term birth to have periodontitis. In this study amniotic fluid was examined and although no bacteria associated with periodontitis were found, levels of interleukin (IL) -6 and prostaglandin – E2 (PGE2) were higher in pre-term cases. The implication is that periodontitis can induce a primary host response leading to pre-term birth.


1.Marin, C., Segura-Egea, J.J., Martinez-Sahuguillo, A. , et al. Correlation between infant birth weight and mother’s periodontal status. J. Clin. Periodontol.32:299-304, 2005.

2.Dortbudak, 0., Ebertardt, R., Ulm, M. , et al. Periodontitis, a marker of risk in pregnancy for pre-term birth. J. Clin. Periodontol 32:45-52, 2005.

3.Moore, S., Randhania, M., Ide, M. A case-control study to investigate an association between adverse pregnancy outcome and periodontal disease J. Clin. PeriodontoI 32:1-5, 2005.


In vital bleaching of teeth, which of the following causes greatest pulpal sensitivity?

A. Whitening strips (10% hydrogen peroxide gel) applied twice daily for seven days.

B. Whitening wraps (8% hydrogen peroxide gel) applied twice daily for seven days.

C. Whitening wraps (8% hydrogen peroxide gel) applied once daily for seven days.

D. None of the above.


A study in which whitening strips were compared to whitening wraps evaluated degrees of colour change in bleached anterior teeth, as well as sensitivity of teeth and gingiva exposed to the process. 76 patients over age 18 completed the investigation. Group 1 had whitening strips (10% hydrogen peroxide gel) applied twice daily for 7 days. Group 2 had whitening wraps (8% hydrogen peroxide gel) applied twice daily for 7 days. Group 3 had whitening wraps ( 8% hydrogen peroxide gel) applied once per day for 7 days. Colour evaluations were made at baseline and 5, 7 and 14 days after use. Although all groups had significant lightening of the teeth, those using wraps twice daily had the whitest teeth. Though both wraps and strips caused pulpal reaction, no differences were recorded between the two. However, users of wraps twice daily reported more gingival sensitivity.

It would seem that over -the-counter products have great variation in peroxide gel strength from 5% to 14%, and the recommended times of application can range from twice daily for 7 days to 21 days of use. Because of this lack of regulation and possible harmful effects to tissues the dentist should give appropriate advice to patients.


1.Matis, B.A., Cochrane, M.A., Wang, G. et al. A clinical evaluation of bleaching using whitening wraps and strips. Operative Dentistry 30:588-592, 2005.


In endodontic therapy, which of the following is associated with the use of E.D.T.A, but not with sodium hypochlorite (NaOCI)?

A. Bacterial cytotoxicity

B. Dissolution of organic material

C. Lubrication

D. Elimination of the smear layer


A recent article discussed not only the importance of root canal irrigation, but also listed suitable ingredients and their clinical value in treatment. Sodium hypochlorite (NaOCI) is the most commonly used with benefits of bactericidal cytotoxicity, dissolution of organic material and lubrication. It will not clean the whole root canal system, however, since it has no effect on the smear layer. To offset this problem, E.D.T.A (0.7%) is used.


1.Sleiman, P and Khaled, F. Sequence of irrigation in endodontics. Oral Health May, 62- 65, 2005.


Which of the following apply/ies to recurrent caries?

1. The incidence is higher for amalgams than for resin-based composites.

2. Recurrent caries is not associated with Class I restorations.

3. Caries is seen predominantly at the gingival margins of restorations.

4. Micro-Ieakage is not associated with recurrent caries.

A. 1, 2, 3

B. 1 and 3

C. 2 and 4

D. 4 only

E. All of the above


The percentage of restorations replaced in adults because of a diagnosis of recurrent caries ranges from 45-55 %. The percentage is higher for amalgams than resin-based composites.

Recurrent caries is seen predominantly on the gingival margins of Class II through Class V restorations and not associated with Class I restorations. Micro-Ieakage has been associated with development of recurrent caries but this is now challenged and instead of a recurrent caries lesion it is seen as a primary surface lesion, which can be treated accordingly. Consideration should be given to repair and refurbishing of localised defects at restoration margins rather than total replacement.

Diagnosis of recurrent caries at proximal and gingival locations of restorations is done by radiography. Radiographs have to be taken at an optimal angle and because most restorative materials are radiopaque the lesion can go undetected. Radiographic burnout often occurs at the cervical margin making interpretation difficult. This accounts for such wide variation in diagnosis. Caution is therefore advocated in the diagnosis of secondary caries and restoration replacement since the tooth is then weakened. Repair rather than remove!


1.Mjr, I.A. Clinical diagnosis of recurrent caries. JADA 136: 1426- 1433, 2005.

Answers to the May 2007 SLSA questions:

17. A

18. C

19. E

20. C