Oral Health Group
Feature

Self learning, Self assessment 2011 (January 01, 2011)

January 1, 2011
by Oral Health


We would like to inform readers that 2011 will be the final year of the SLSA program in Oral Health. The program for 2011 will consist of 20 items. We will publish four items every other month with an 8-question Quiz appearing in the November 2011 issue. Because the program is half its usual length, provincial licensing authorities may alter the allocation of CE credits.

QUESTION 1
A cracked tooth
1. occurs most frequently in adults.
2. is associated with a tooth with intracoronal restor­ations.
3. is most prevalent in mandibular molars.
4. is rarely found in mandibular premolars.

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A. 1, 2, 3    D. 4 only   
B. 1 and 3    E. All of the above
C. 2 and 4

Rationale
The American Association of Endodontics has classified five variations of cracked teeth – craze line, fractured cusp, cracked tooth, split tooth, and  vertical root fracture. In diagnosis it should be noted that 80% of cracked teeth occur in patients over 40 years of age and that the problem is seen most frequently in mandibular molars especially when intracoronal restorations are present. Maxillary molars and premolars have an equal incidence while mandibular premolars are least susceptible.

For both diagnosis and treatment, the character, duration and stimuli of pain have important implications:
1) dentine pain is brief with a sharp twinge.
2) pulpal pain is deep, demanding, radiating and precipitated by thermal shock to an inflamed pulp.
3) periodontal pain is throbbing.

Dentine fractures are not generally evident radiographically. Having identified the tooth an offending cusp can be located  by load testing. When the tooth is identified it should be anaesthetized, isolated with rubber dam, and all restorations removed. With dyes, microscopes or transillumination it should then be possible to identify the fracture and its extent.

REFERENCE
1. Kahler, W.  The cracked tooth conundrum:  Terminology, classification, diagnosis and management.  Am J Dent  21: 275 – 282, 2008.

QUESTION 2
Dentine hypersensitivity is a common concern.

Dentine hypersensitivity is characterized by short sharp pain from exposed dentine in response to stimuli.

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
Of common occurrence, the diagnosis of dentine hypersensitivity can be difficult. Differential diagnosis has to be made between pain of a split tooth, dental caries or periodontal disease. To be hypersensitive, dentin must be exposed and exposed dentin tubules have to be open and patent to the pulp.  Gingival recession from abrasion or periodontal disease exposes dentin and acid erosion is a factor in opening of tubules. Pain is caused by various stimuli-thermal, evaporative, tactile, or chemical.

Treatment and prevention rely on two approaches, one which interferes with transmission of nerve impulses and the other which occludes dentine tubules. For the former, potassium salts are used as numbing agents. Delivered in a dentifrice the ions of potassium enter the tubular fluid and affect the electrical nerve conduction. Four to eight weeks use is needed for relief. Blocking of tubules can be done professionally and/or in home care. Fluoride varnish (22,500 ppm) and high level fluoride toothpastes and gels (5,000 ppm) are effective. A new occlusion technology is based upon 8% arginine and calcium carbonate in the form of a paste (Colgate sensitive Pro-Relief  Desensitizing Paste). Studies with this product record patients having instant relief which, after one application lasts for 28 days. Under electronmicroscopy plugs of the arginine-calcium carbonate are found to a depth of 2 microns in the tubules.

REFERENCE
1. Panagakos, F., Schiff, T., Guignon, A.  Dentin hypersensitivity:  Effective treatment with an in-office desensitizing paste containing 8% arginine and calcium carbonate.  Am J Dent  22 : 3A – 7A 2009.

QUESTION 3
A tension type headache is affected by TMJ disorders.

Headache is associated with bruxism.

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
Masseter muscles show essential and significant relationship to headache. Internal derangement of the TMJ increases activity of masseter and temporalis muscles.  Pain in the masseters has a distinct connection to headaches. In all headache patients , bruxism and increased tongue pressure against the teeth is more prevalent and is considered to play a role in both migraine and tension type headaches. In a study of headache sufferers who clench, it was found that clenching for 30 minutes could cause immediate headache. It is further thought that bruxism may be a factor in converting episodic  tension headaches into chronic ones. The use of an intra oral stabilization occlusal splint can reduce tension type headaches by 70 – 80%.

REFERENCE
1. Lasbovitz, B.M.  Tempomandibular disorders and headache:  A review of the literature.  Oral Health June 12 – 17, 2006.

QUESTION 4
Injection of the local anaesthetic prilocaine plain causes less pain than
1. articaine with 1 : 100,000 epinephrine.
2. lidocaine with 1 : 100,000 epinephrine.
3. mepivacaine plain.
4. bupivacaine 0.5% with 1 : 200,000 epinephrine.

A. 1, 2, 3    D. 4 only
B. 1 and 3    E. All of the above
C. 2 and 4

Rationale
A study of injection pain involving 1,391 patients resulted in similar results from amongst articaine, lidocaine and mepivacaine. A statistically significant decrease in pain perception was recorded for prilocaine plain. In another study involving bupivacaine 0.5% with 1 : 200,000 epinephrine and prilocaine 4% plain, less pain was again recorded with the prilocaine.  Prilocaine’s reduced injection pain may be related to its pH which is relatively neutral at 6.0 – 7.0 whilst the others have an acid pH of 3.5 – 5.5. However, anaesthetic toxicity is a most important factor in the choice of a local anaesthetic.  Lidocaine 2% with 1:100,000 epinephrine has the widest margin of safety per cartridge of all commercially available formulations. Each lidocaine cartridge of 2% with epinephrine is half as toxic as mepivacaine 3% plain.

REFERENCE
1. Wahl, M.J., Brown, R.S.  Dentistry’s wonder drugs:  Local anaesthetics and vasoconstrictors.  Gen Dent  March/April 114 – 121  2010.

Answers to the 15 question quiz that appeared in the November 2010 issue:
1. E
2. A
3. E
4. B
5. D
6. C
7. A
8. E
9. C
10. C
11. C
12. E
13. C
14. B
15. E