The presence of fluoride in communal water supplies have demonstrated appreciably lesser benefits, this is due to:

 # The presence of fluoride in communal water supplies have demonstrated appreciably lesser benefits, this is due to 

A. Adverse effect 

B. Halo effect 

C. Bacteriostatic effect 

D. None of the above 

The correct answer is B. Halo effect.

Several studies concerning the reduced prevalence of dental caries associated with the presence of fluoride in communal water supplies have demonstrated appreciably lesser benefits, typically ranging between 18% and 30%. This decrease in attributable benefit is due to the so-called halo effect associated with the preparation of numerous foods and beverages in fluoridated communities and their consumption in nonfluoridated communities.

Reference: Mc Donald 2nd South Asian Edition

The reversal agent used in clinical practice to treat benzodiazepine overdose:

 The reversal agent used in clinical practice to treat benzodiazepine overdose

A. Romazicon 

B. Naloxone

C. Sublimaze

D. Demerol

The correct answer is A. Romazicon.

-Flumazenil (Romazicon) is a direct, specific reversal agent used in clinical practice to treat benzodiazepine overdose. Pharmacologically, it acts as a competitive antagonist at the benzodiazepine receptor sites in the CNS. 

-Naloxone is a life-saving medication that can reverse an overdose from opioids, including heroin, fentanyl, and prescription opioid medications.

-Fentanyl (Sublimaze) is a potent synthetic opiate agonist. A dose of 0.1 mg is approximately equivalent to 10 mg of morphine or 75 mg of meperidine. Fentanyl acts rapidly, and after intramuscular injection the onset occurs in 7–15 min; duration of effects is 1– 2 h.

-Meperidine (Demerol) is a synthetic opiate agonist, closely related to fentanyl in chemical structure.

Reference: Mc Donald 2nd South Asian Edition

Genetic factors play a role in the aetiology of:

 # Genetic factors play a role in the aetiology of: 

A. Chronic periodontitis 

B. Aggressive periodontitis 

C. Both of the above 

D. None of the above 

The correct answer is C. Both of the above.

Though genetic factors play a dominant role in Aggressive cases, they are considered to be the aetiological factors in all kinds of periodontitis. 

Incisor liability in maxillary arch

 # Incisor liability is about ………..in maxillary arch.

A. 4.6 mm 

B. 5.4 mm 

C. 6.2 mm 

D. 7.6 mm 

The correct answer is D. 7.6 mm.

Incisor liability is about 7.6 mm in maxillary arch and 6 mm in mandibular arch. The incisor liability is compensated by three mechanisms:

a. Increased intercanine width: During the period of permanent incisor eruption, significant amount of increase in intercanine arch width occurs. It is about 3–4 mm.

b. Interdental spacing: Spacing present in primary dentition helps in alignment of incisor. The primate space present in the upper arch mesial to primary canine is also used.

c. Labial eruption of incisor: Primary incisor stand upright. The permanent incisors, which replace them, are labially proclined placing them in a wider arch.

Source: Mc Donald 2nd South Asian Edition