Final answer:
The first step in root canal therapy is Access Preparation, where an opening is made through the crown to access the pulp cavity. Microbes, particularly Streptococcus mutans, contribute to tooth decay by dissolving enamel with acids.
Step-by-step explanation:
First Step in Root Canal Therapy
The first step in root canal therapy is Access Preparation. Before the dentist can clean and shape the root canal, or perform the obturation (filling) of the root canal and the final restoration of the tooth, they must gain access to the infected or damaged tissues within the tooth. This involves creating an opening through the crown of the tooth to reach the pulp cavity within the root canal. If caries have developed and affected the pulp, a root canal procedure is essential to remove the infection and prevent the spread, which could lead to abscesses and more severe complications.
Microbes contribute to tooth decay by forming a biofilm (plaque) on the teeth and releasing acids as they metabolize sugars, which gradually dissolve tooth enamel and can lead to more serious infections of the dentin and pulp. The most important cariogenic species of bacteria is Streptococcus mutans, which is particularly adept at adhering to teeth and producing lactic acid.