What are the different stages of dental cavities?

Really?: Small hole that needs fixing. Bigger hole that needs fixing. Large hole that should have been fixed. Hole that made it to nerve and now tooth needs root canal. Decay has leveled tooth since it was never fixed and now needs to be extracted.

Cavities in teeth: Tooth enamel is susceptible to decalcification by the acids produced by the bacteria that normally inhabit the mouth. Acid produced by the bacteria first begin to weaken the enamel though this decalcification. Once this process reaches the softer "dentin", the bacteria actually accelerate the process, resulting in a "hole" in the enamel and the dentin.

Decay stages: Decay starts at the enamel of the tooth and breakdown is related to acids in the food or made by bacteria in the mouth this typically starts in pits and fissures on the back teeth or between teeth. As the decay progresses deeper into the tooth it contacts the dentin which is softer then the overlaying enamel and blooms from there progressing deeper into the tooth

Stages: Incipient caries is earliest stage, when bacterial produced acids begin to etch calcium out of the heard enamel outer coating. once cavity penetrates enamel, reaches softer underlying dentin, bacteria/acids race toward tooth's pulpal tissues. When bacteria enter the tooth's pulp the collection of pus is known as an abscess. The earlier a cavity is found/treated, the simpler/less expensive the Rx.