Tooth scraping often involves collecting a sample of dental plaque from the surface of the teeth. Dental plaque is a biofilm that consists of various microorganisms, including bacteria. When examining the bacteria present in a tooth scraping sample, it is important to identify their morphology to better understand their characteristics and potential implications for oral health.

The bacteria in the tooth scraping are described as corkscrew-shaped. This shape is indicative of a spiral or helical morphology. There are several different types of spiral-shaped bacteria, but the most common ones are referred to as spirilli. Therefore, the correct answer to the question is option 'C' - Spirilli.

Spirilli bacteria are characterized by their corkscrew or spiral shape. They have a rigid cell wall and flagella that allow them to move in a spiral manner. These bacteria can be further classified based on their size, number of flagella, and other characteristics.

Some examples of spirilli bacteria include:

1. Treponema pallidum: This bacterium is responsible for causing syphilis, a sexually transmitted infection. It has a tight helical shape and is very thin.

2. Borrelia burgdorferi: This bacterium causes Lyme disease, which is transmitted through tick bites. It has a long, flexible spiral shape.

3. Campylobacter jejuni: This bacterium is one of the most common causes of bacterial gastroenteritis. It has a curved or S-shaped morphology.

The presence of corkscrew-shaped bacteria in a tooth scraping sample could indicate the presence of certain oral pathogens. Some spiral-shaped bacteria are associated with oral diseases such as periodontal disease and halitosis (bad breath).

In conclusion, the corkscrew-shaped bacteria obtained from a tooth scraping are referred to as spirilli. These bacteria have a spiral or helical shape and can be associated with various oral diseases.