Oral Health Group

2003 Self Learning Assessment (March 01, 2003)

March 1, 2003
by Oral Health

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.



The PerioChip

1.contains 2.5 mg chlorhexidine gluconate.

2.releases chlorhexidine into the crevicular fluid.

3.is beneficial in maintenance therapy.

4.inhibits growth of pocket flora for 24 hours only.

A.1, 2, 3

B.1 and 3

C.2 and 4

D.4 only

E.All of the above


The PerioChip consists of a biodegradable delivery system, which contains 2.5 mg of chlorhexidine gluconate in a cross-linked hydrolysed gelatin vehicle. After placement, it causes a release of 2000 g/ml chlorhexidine into crevicular fluid as a peak concentration. The drug remains above the minimum inhibitory concentration to more than 99% of the periodontal pocket flora for up to nine days.

The PerioChip is recognized as beneficial adjunct therapy immediately following the initial treatment phase after scaling and root planing. A recent study examined its value in maintenance patients. Plaque, pocket-probing depth, bleeding index, as well as clinical attachment levels were assessed in patients using a split mouth technique for comparison purposes. PerioChips were placed in selected sites, while other sites in the same mouth were devoid of antimicrobial therapy.

Data indicate that the PerioChip is an efficacious adjunct treatment to scaling and root planing. However, the benefit of such adjunct treatment for maintenance patients only becomes apparent after six months, at which time, improvement is seen in pocket depth, clinical attachment levels, and in the bleeding index.


1.Heasman, P.A., Heasman, L., Stacey, F. et al. Local delivery of chlorhexidine gluconate (PerioChip(tm)) in periodontal maintenance patients. J Clin Periodontol 28:90-95. 2001.


The use of a clinical microscope can

1. decrease trauma in tissue retraction.

2. aid in the injection of impression material.

3. result in improved cavity preparation.

4. increase precision of hand/eye coordination.

A. 1, 2, 3

B. 1 and 3

C. 2 and 4

D. 4 only

E. All of the above


It is now recognized that even the best normal vision is not as good as vision assisted with the magnification and illumination provided by a clinical microscope. Such magnification not only improves vision, but also allows for a more favourable posture for the dentist and better patient care.

With the aid of a microscope, small shadows can be diagnosed more correctly as caries, open margins, microleakage or fractures. Incipient lesions can be diagnosed more quickly and treated less traumatically. Marginal adaptation of a restoration can be examined in greater detail. Magnification aids in the injection of impression material around the preparation site as it allows the clinician to see the material moving into the sulcus. Impression accuracy can be examined through the microscope as well. The microscope facilitates the delicate handling of tissues and decreases tissue trauma, as well as improved cavity preparation.

The dentist can work freely between magnification factors of 2 to 21, while maintaining visual acuity and good posture. The use of an intraoral mirror provides visual access comparable to an endoscope, permitting viewing in any set of axes. When using aesthetic materials, filters incorporated onto the microscope can enable the clinician to distinguish between the material and the tooth structure. Despite the advantages, some dentists regard the use of a clinical microscope as an unnecessary burden. It does take time to adjust to the use of the instrument, but persistence will result in increased skill, precision of hand/eye coordination, and higher quality care.


1.Sheets, C.G., Paquette, J.M. The Mastership Series: The magic of magnification. Dent Today 16(12). 1998.

2.Sheets, C.G., Paquette, J.M. Is magnification for you? Dent Econ 91:102-106. 2001.

3.Oral Care Report, Vol. 11, Number 2. Chester Douglass, Editor. 2001.


Which of the following conditions would place a patient at increased risk for stroke?

1. Chronic periapical infection.

2. High levels of alveolar bone loss.

3. Chronic periodontal infection.

4. TIAs (transient ischemic attacks).

A. 1, 2, 3

B. 1 and 3

C. 2 and 4

D. 4 only

E. All of the above


Because of the high prevalence of dental disease, particularly among seniors, any identified associations with systemic disease outcomes are important. In Canada and the USA up to 33% of the elderly have periodontitis; 48% have gingivitis; 40% are edentulous.

A study conducted in the USA showed that, compared to individuals with good oral hygiene, those with periodontal disease had twice the risk of suffering a stroke. This relationship was found to be true for men, women, blacks and whites. However, this increased risk was only for non-haemorrhagic stroke, where loss of blood flow to the brain was due to a blockage rather than to a ruptured vessel.

Other studies have found a strong association between alveolar bone loss and stroke. Those with high levels of bone loss were almost three times more likely to suffer a stroke than individuals with low levels of bone loss. Although chronic periodontal infection was found to be associated with an increased risk of stroke, the relationship between chronic periapical infection and stroke appeared to be the stronger. Although the management of TIAs is a medical responsibility, the dentist should recognize that a patient with such a history is at increased risk for stroke.


1.Wu, T. Trevisan, M., Genco, R.J., et al. Periodontal disease and risk of cerebrovascular disease: The first national health and nutrition examination survey and its follow-up study. Arch Int Med 160:2749-2755. 2000.

2.Graau, A.J., Buggle, F. Ziegler, C., et al. Association between acute cerebrovascular ischemia and chronic and recurrent infection. Stroke 28:1724-1729. 1997.


Chewing sugar-free gum sweetened with xylitol

1. does not reduce levels of streptococcus mutans.

2. inhibits plaque growth.

3. has no anticariogenic effect.

4. increases salivary flow.

A. 1, 2, 3

B. 1 and 3

C. 2 and 4

D. 4 only

E. All of the above


A number of studies have shown that chewing of sugar-free gums will reduce caries. Initially, this was believed to be due to increased salivary flow, which enhances the buffering capacity of saliva, thereby neutralizing the decrease in plaque pH that occurs after meals. It has now been shown that chewing gums made up of different constituents can affect the incidence of dental caries. It is, therefore, not just the act of chewing and increased salivary flow that affect the result.

Sugar-free gums contain either sorbitol or xylitol. Sorbitol is 60% as sweet as sucrose. It can be fermented by oral flora, including the microrganisms implicated in caries. Xylitol, on the other hand, is as sweet as sucrose and is not fermented by the oral flora. Studies have shown that all sugar-free gums can decrease the caries onset rate, but gum containing 100% xylitol is the most effective.

Sugar-free gums have also been shown to inhibit plaque growth, reduce the number of streptococcus mutans in saliva and improve gingival health. The data are strongly suggestive that xylitol-containing gum is anticariogenic in human subjects.


1.Gales, M.A., Nguyen, T.-M. Sorbitol compared with xylitol in prevention of dental caries. Ann Pharm 34:98-100. 2000.

2.Mkinen, K.K., Pemberton, D., Mkinen, P.L., et al. Polyol-combinant saliva stimulants and oral health in Veterans Affairs patients-An exploratory study. Spec Care Dent 16:104-116. 1996.

3.Tanzer, J.M., Xylitol chewing gum and dental caries. Int
Dent J 45:65-76. 1995.

Answers to February 2003 SLSA Quiz

5. E

6. E

7. E

8. E

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