**Question:** A 25 year old male patient complains of pain in the lower back tooth region. History of similar complaint 6 months ago.
Intra-oral examination reveals pericoronitis with 36. An IOPA is taken with the same tooth. During film processing, the thermometer in the manual processing tank reads 68◦F. The approximate time to keep the x-ray film in the developer solution is?

A. 30 minutes
B. 45 minutes
C. 60 minutes
D. 90 minutes

**Core Concept:** In manual dental radiography, the development time of dental x-ray films depends on the temperature of the developer solution and the film type.

**Why the Correct Answer is Right:**

The correct answer is **D. 90 minutes**. The development time in manual dental radiography depends on the temperature of the developer solution and the film type. A higher temperature accelerates the development process, reducing the development time needed for the film to reach the optimal sensitivity required for accurate diagnostics. In this scenario, the processing tank's temperature is 68°F (20°C), which is considered too low for optimal film development.

**Why Each Wrong Option is Incorrect:**

A. 30 minutes: This is too short for proper development of the film at the given low temperature.
B. 45 minutes: Although not too long, this is still less efficient than the optimal development time.
C. 60 minutes: This is longer than the optimal development time, which may lead to overdevelopment and reduced film quality.

**Clinical Pearl:**

For accurate dental radiography, maintaining an optimal film development time is crucial. In manual processing tanks with temperatures below 70°F (21°C), the development time should be longer than usual to ensure proper film sensitivity and quality. This ensures reliable diagnosis and minimizes image artifacts due to over- or underdevelopment.

**Correct Answer Explanation:**

The correct answer, **90 minutes**, is chosen because at a low temperature of 68°F (20°C), it takes longer than the typical development time to achieve optimal film sensitivity. Lower temperatures slow down the development process, so the developer must be given more time to work effectively. This ensures accurate diagnostics, as the film is allowed to develop properly despite the suboptimal processing conditions.