The most well recognized technique for orthodontic bonding to porcelain surfaces is:

 # The most well recognized technique for orthodontic bonding to porcelain surfaces is:

A. Traditional acid-etch technique with phosphoric acid.

B. Chemical retention using 4-META coupling agent.

C. Chemical and micro-mechanical retention using hydrofluoric acid and a silane coupling agent.

D. Chemical retention using hydrofluoric acid only.

The correct answer is C. Chemical and micro-mechanical retention using hydrofluoric acid and a silane coupling agent

Explanation:
The most effective and well-recognized technique for bonding to porcelain involves etching the porcelain surface with hydrofluoric acid to create micro-mechanical retention, followed by the application of a silane coupling agent to enhance chemical adhesion. This combination ensures a strong bond between the orthodontic bracket and the porcelain surface.

• A: Phosphoric acid etching is effective for enamel but not adequate for porcelain bonding.
• B: 4-META is less commonly used for porcelain.
• D: Hydrofluoric acid alone provides micro-mechanical retention but lacks the chemical bond achieved with silane.

How many hours after appliance placement does orthodontic pain peak?

 # How many hours after appliance placement does orthodontic pain peak?

A. 10 minutes.

B. 1 hour.

C. 24 hours.

D. 48 hours.

The correct answer is C. 24 hours.

It is generally considered that orthodontic pain starts at around 2 hours after appliance placement, with some studies reporting that this is the case for between 91% and 97% of orthodontic patients. It then usually peaks at 24 hours before gradually subsiding over the next 5 to 7 days. Interestingly, it would seem that up to 25% of orthodontic patients report experiencing pain for longer than 7 days.

In pain pathways the smaller primary unmyelinated fibres are called:

 # In pain pathways the smaller primary unmyelinated fibres are called:

 A. A fibres. 

B. B fibres. 

C. C fibres. 

D. D fibres.

The correct answer is:

C. C fibres

Explanation: C fibres are small, unmyelinated nerve fibers that conduct pain signals slowly. They are primarily responsible for transmitting dull, burning, or aching pain (slow pain) and are involved in the prolonged, less localized pain sensation.

A fibres: Include A-delta fibers, which are myelinated and transmit sharp, localized pain quickly (fast pain).

B fibres: Small, myelinated fibers mainly involved in autonomic functions.

D fibres: This category does not exist in standard nomenclature for nerve fibers.

Enzyme marker of acute alcohol toxicity

 # A person with a long history of alcohol intake reports with acute alcohol intoxication. Which of the following enzymes is a marker of acute toxicity?

A. AST

B. ALT

C. GGT

D. Alkaline phosphatase

The correct answer is:

C. GGT (Gamma-Glutamyl Transferase)

Explanation:
Gamma-glutamyl transferase (GGT) is a sensitive marker for alcohol consumption and acute alcohol toxicity. It is elevated in conditions involving liver damage, particularly from chronic alcohol use. While AST and ALT may also be elevated in liver damage, GGT is more specific for alcohol-related effects. Alkaline phosphatase is primarily associated with biliary obstruction or bone disorders.