Tartar is formed when a person does not take care of his oral hygiene properly. This happened when the accumulated plaque is not cleaned. After a considerable amount of time, it hardens to form tartar. It is well known that tartar can easily have a lot of bacteria gathered in it. These bacteria practically live and thrives on tartar. Since it cannot be easily removed, the bacteria continue to grow and reproduce on the teeth. They digest the remains of the food when a person consumes them. Then they produce acids which can very easily eat away the enamel of the tooth. This also evidently results in cavities.
If left untreated, they can go deeper into the enamel and cause decay. If this decay reaches the pulp of the tooth, then a person has no other choice but to get either a root canal or perhaps even complete extraction of the tooth. All of this results in severe pain for the person suffering from it.
Even the mere presence of the bacteria in tartar causes inflammation. Over time it leads to a situation called periodontitis. Just like any other bacterial condition, this can grow and trigger other complicated dental conditions if these are left ignored or untreated. To avoid all these conditions, it is better than you seek an in-office dental cleaning to remove the tartar gathered on the teeth.