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

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 9
For an otherwise healthy young adult with an acute dentoalveolar abscess, without systemic involvement, which of the following would be your first choice of antibiotic therapy?
A. Amoxicillin.
B. Metronidazole.
C. Clindamycin.
D. Erythromycin.
E. None of the above.

Rationale
In the current climate of evidence-based medicine an attempt is made to rationalize the use of antibiotics for adult patients presenting with acute dentoalveolar infections. Most can be successfully treated with surgical drainage followed by removal of the cause of infection.; For those patients who have become systemically unwell, or who are immunocompromised, the same principles are followed along with adjunctive antibiotic therapy to manage their systemic involvement.

Systemic involvement signs include elevated body temperature, gross swelling, trismus, regional lymph­adenopathy and tachycardia. For acute dentoalveolar infections, which are mixed infections, the antibiotic of choice is amoxicillin, followed by metronidazole and then clindamycin. For pericoronitis, periodontal abscess and ANUG, which are primarily anaerobic infections, the drug of choice is metronidazole followed by clindamycin. For an antibiotic to be successful, it must be active against the microorganisms present and be given in adequate dose, frequency and duration. Historically antibiotics have been prescribed for between 5-10 days. It is now becoming evident that long courses of antibiotics are not required and indeed may destroy the homeostasis of the oral microflora, leading to resistant strains. Antibiotics are prescribed with the intention of eradicating microbial systemic involvement and can be discontinued safely after the resolution of these signs, usually 2-3 days. Immuno­compromised patients may require more radical use of antibiotics. The ratio of risk to benefit must be considered on an individual patient basis.

Reference
1. Ellison, S.J. The role of phenoxymethylpenicillin, amoxicillin, metronidazole and clindamycin in the management of accute dentoalveolar abscesses – a review. Br Dent J 206: 357 – 361, 2009.

Question 10
Multiple sclerosis
1. is a chronic inflammatory, demyelinating disease of the CNS.
2. affects mostly young adults.
3. is increasing in prevalence and incidence.
4. is characterized by periods of activity and remission.
A. 1, 2, 3
B. 1 and 3
C. 2 and 4
D. 4 only
E. All of the above.

Rationale
Multiple sclerosis (MS) is a chronic, inflammatory demyelinating disease of the central nervous system which affects mostly young adults and is increasing in prevalence and incidence. The presentation and course of the disease vary significantly, but it is generally marked by recurrent attacks of neurologic dysfunction, followed by remission which, after numerous relapses, cause permanent neurologic deficits.

The oral health care provider should be able to recognize the signs and symptoms of the orofacial region and be able to distinguish them from signs and symptoms of dental origin. The most common presenting symptoms include intermittent unilateral facial numbness or pain, facial palsy or spasm, impaired ability to articulate words, visual disturbances and diplopia. These attacks typically last for at least 24 hours with an average frequency of three times per year. Patients presenting with this symptomatology should be referred to a neurologist for investigation.

There are no contraindications to dental treatment, but optimal time for treatment is during periods of remission.

Reference
1. Fischer, D.J., Epstein, J.B. and Klasser, G. Multiple sclerosis: an update for oral health care providers. Oral Surg, Oral Med, Oral Path, Oral Rad and Endodont 108 : 318 – 327, 2009.

Question 11
In diagnosis of a cracked tooth it is important to determine the
A. character of the pain.
B. duration of the pain.
C. causal stimuli
D. All of the above.

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 12
Which of the following provide(s) immediate relief of pain from dentine hypersensitivity?
A. Fluoride varnish.
B. Fluoride tooth paste.
C. Arginine and calcium carbonate paste.
D. All of the above.
E. None of the above.

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 significant 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.

RELATED NEWS

RESOURCES