Oral Health Group

Self Learning, Self Assessment 2007

January 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.



For a woman of child-bearing age with periodontitis, which of the following would apply?

1. The birth weight of her baby could be reduced.

2. The greater the severity of periodontitis, the greater the risk of pre-term birth.

3. The risk of pre-term birth would be increased.

4. Periodontitis would affect neither birth weight, nor induce pre-term birth.

A. 1, 2, 3

B. 1 and 3

C. 2 and 4

D. 4 only

E. All of the above


A study involving 152 Caucasian women examined a possible correlation between periodontitis and infant birth weight. Three groups were studied; a healthy group, a gingivitis group, and a group with periodontitis. At delivery, birth weight was recorded. The women were aged 14-39 years. In the group of women over 25 years infant birth weight was greatest in the healthy group, slightly lower in the gingivitis group, and lowest in the group with periodontitis. The related figures were statistically significant.

A second 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.

The third study cited here examined post-partum groups of women–those with pre-term delivery and those with birth at or around term. Periodontal examination showed no difference in oral hygiene, bleeding on probing or loss of attachment. However, mothers with pre-term births showed a higher proportion of periodontal pockets 5mm or greater. There was no association between severity of periodontal disease and pregnancy outcome.


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 Periodontol 32:1-5, 2005.


When using whitening strips or wraps for home bleaching of teeth, which of the following is/are correct?

1. The active bleaching agent is 8-10% hydrogen “peroxide gel.

2. Wraps are more efficient than strips.

3. Wraps cause more gingival sensitivity.

4. Neither causes pulpal reaction.

A. 1, 2, 3

B. 1 and 3

C. 2 and 4

D. 4 only

E. All 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.


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.


As an irrigant in endodontics, sodium hypochlorite (NaOCI) is sufficient to clean the whole root canal system.

After gaining access to the canal, an endodontic file should be used to explore the canal topography.

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.


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.

Although commonly done, the introduction of an endodontic file to the root canal after gaining access is rejected because it spreads bacterial toxins into the canal system and periapical area and it tends to aggregate pulpal tissue into an organic plug, making irrigation and shaping more difficult. The initial step should be application of NaOCI with alternate use of E.D.T.A. Early use of the latter facilitates the flow of different irrigants. Ultrasonic activation of irrigating solutions with a small diameter file makes chemical preparation more efficient.


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


Recurrent caries is the most common cause of replacement of restorations.

Diagnosis of recurrent caries lacks consistency and shows a great variation among clinicians.

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.


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-leakage 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 localized 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!


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


1. C

2. E

3. A

4. A

5. D

6. D

7. B

8. E

9. E

10. E

11. E

12. D

13. A

14. E

15. A

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