Oral Health Group
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Learning Assessment (September 01, 2000)

September 1, 2000
by Oral Health


The SLSA program is based on current, referenced literature and consists of 40 questions, answers, rationales and references.

Dentists who complete the 15 question quiz in the November, 2000 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.

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QUESTION 33

In endodontic treatment, camphorated monochlorophenol (CMCP)

1. is nontoxic to tissue.

2. is effective for 72 hours.

3. can dissolve necrotic debris.

4. is antimicrobial.

A. 1, 2, 3

B. 1 and 3

C. 2 and 4

D. 4 only

E. All of the above

Rationale:

Camphorated monochlorophenol and other phenols, including eugenol, are effective antimicrobials, but they are toxic and much of their efficacy is lost after 24 hours. CMCP cannot dissolve necrotic debris in root canals.

Antimicrobial medicaments must be recognized as only supplementary to thorough and careful instrumentation. Meticulous debridement and irrigation are much more important than what is placed in the canal.

REFERENCE:

Doran, M.G., Radtke, P.K., A review of endodontic medicaments. J General Dent Oct:484-88, 1998.

QUESTION 34

Two implants were placed in the anterior maxilla of a 10-year-old girl to replace an avulsed central and lateral incisor. At age 21, in relation to the arch, you would expect to find these implants

A. in normal alignment.

B. lingual to the arch.

C. labial to the arch.

Rationale:

The replacement of maxillary incisors with implants in growing patients should only be attempted after the potential growth status of the patient has been ascertained. Hand-wrist radiographs provide the best method for determining the maturational status of a pubertal patient. No implant should be placed in the anterior maxillary region during the accelerating phase of pubertal growth or before. Implants in the anterior maxillary region of circumpubertal females should be placed at an age coinciding with the decelerating phase of the pubertal growth spurt or later. The growth of the average 10 year old girl would not have slowed sufficiently for implants to be placed.

If the implants are placed prior to final growth of the maxillary alveolus, the implants will not move with the alveolus as growth proceeds and will come to lie in a palatal position with a poor esthetic result.

REFERENCE:

Ranly, D.M. Implants in the circumpubertal patient: Growth considerations. Am J Dent 11:86-92, 1998.

QUESTION 35

The full veneer technique allows for

A. enamel augmentation.

B. major masking of stained teeth.

C. alteration of tooth size.

D. alteration of alignment.

E. All of the above

Rationale:

The full veneer technique is most appropriate when tooth position or size needs to be altered, enamel augmentation is needed, or major colour masking is demanded. When using veneers on malaligned teeth to create the illusion of well-positioned teeth, a full veneer allows appropriate build-up of enamel. Such veneer treatment is also recommended for diastemas. The proportion of tooth size can be better matched with a full veneer. In cases of discoloured teeth, the full veneer eliminates the dark shadows at the edges. Where gingival recession has occurred with spaces in the embrasures, a traditional veneer preparation results in elongation of the tooth and widening of the facial contact. A full veneer preparation can be used to prevent these anatomic irregularities.

When preparing a tooth for a full veneer, the cut should extend to the lingual of the tooth, breaking the interproximal contact. Interproximal enamel is thick and allows this extension with little involvement of dentin. With this technique, however, prepared teeth must be well temporized to prevent migration and sensitivity.

REFERENCE:

Route, J.S. Full veneer versus traditional veneer preparation: A discussion of interproximal extensions. J Prosth Dent 78:545-549, 1997.

QUESTION 36

In 90 percent of Class I uncrowded cases, removal of maxillary deciduous canines before the age of 11 years will result in normal positioning of ectopically erupting permanent canines if the canine crown is distal to the midline of the lateral incisor.

The greater the severity of angulation of an unerupted permanent canine tooth, the less the probability of spontaneous eruption.

A. The first statement is true, the second is false.

B. The second statement is true, the first is false.

C. Both statements are true.

D. Both statements are false.

Rationale:

In the prevention of maxillary canine impaction, if a clinician detects early signs of ectopic eruption of the canines, selective extraction of deciduous canines should be made as early as 8 or 9 years of age as an interceptive approach to canine impactions in Class I uncrowded cases. Erickson and Kurol suggest that removal of deciduous canines before 11 years of age will create a normal position of ectopically erupting permanent canines in 91 percent of cases, if the canine crown is distal to the midline of the lateral incisor.

If the canine crown is mesial to the midline of the lateral incisor, chances of normal eruption of the canine decrease. A further important prognostic factor in addition to the position of the impacted tooth is the severity of its angulation. The more inclined the tooth is, the less the probability of spontaneous eruption.

Possible sequelae of canine impactions range from loss of space in the arch to resorption of roots of the neighbouring teeth. It is therefore imperative to manage the ectopically erupting canine as early as possible.

REFERENCES:

1.Bishara, S.E., Clinical management of impacted maxillary canines. Seminars in Orthodontics. 4:87-98, 1998.

2.Erickson, S., Kurol, J., Early treatment of palatally erupting maxillary canines by extraction of primary canines. Eur J Orthod 10:283-95, 1988

Answers to the August 2000 SLSA questions:

29. B 30. E 31. A 32. C