Pulpitis refers to an inflammation of the tooth nerves.

The characteristics of a tooth inflammation are easier to understand if one knows something about tooth anatomy. A tooth consists of

dental pulp (also known as dental nerve, or pulpa in Latin)

dental enamel

and dentine (or dentin in Latin)

The pulp consists of nerves, lymph vessels, connective tissue and blood vessels. The dentine is full of little channels which are directly connected to the pulp. The greater the defect in the tooth, the larger the dentine wound and the greater the possibility of an inflammatory reaction of the pulpa.

Inflammation means swelling, for which there is no place in the inside of the tooth, so depending on the intensity of the inflammation, there might be a compression of the blood vessels – which may cause pulp tissue to die due to poor circulation.

The causes of pulp inflammation can be either

infectious damage (caused by bacteria in cavities)

or
non-infectious damage (referring to physical

or chemical damage – for example caused by heat when drilling, or by chemicals )

For treatment it is important to make this distinction, since an infection increases the danger that cavity bacteria may spread throughout the pulp and into the bones and thus cause inflammation to the bone – as can be seen in the animation to the left.

Even when there are no bacteria, there may be inflammation in the bone. Think of the following: the tooth is filed down for a crown, water cooling is inadequate and the pulp gets inflamed due to overheating and dies. Dead tissue, like bacteria, is removed by the immune system. But if there is too much dead tissue, depending on the root anatomy at hand, the immune system cannot remove all of it. Not enough immune cells results in bone inflamation – as seen in the animation to the right.

Usually, the body manages to remove the dead non-infected tissue, and the root canal calcifies (known as root sclerosis). Years later, root canal sclerosis can result in root resorption – the root „turns“ to bone. All these processes may take place simultaneously on one tooth. The picture shows an x-ray of a tooth which was covered by a crown years before; overheating while filing down the crown probably damaged the dental pulp. Years later root resorption occurred, and root canal sclerosis on the short front root; as well as bone inflammation on the rear root tip – the dark spot.

To better understand the results of dental nerve inflammation, it helps to know something about the immune system. Our immune system is capable of recognizing foreign and dangerous structures and eliminating them. „Marker cells“ recognize and mark foreign structures (e.g. bacteria, dead cells, remains of cells, viruses, fungi). “Phagocytes“ (scavenger cells) recognize these markings and remove these elements. The inflammation is prevented. An immune reaction thus requires immune cells, which are found in the blood. Blood needs to be able to flow around the cente of inflammation in order for the inflammation to be „fought“ effectively. The dead pulp tissue is like a „calcium hole“ without blood vessels; with maybe a few cell remains left on the walls. Blood vessels and thus immune cells are only in the bone. Thus, bacteria which have found a way through a deep cavity have prime conditions for multipying in the absence of blood – they are protected from the immune system in the pulp hole They feed on tissue remains and multiply without interference. At some point their number becomes so great that the bacteria spread to the tip of the tooth through a small opening in the bone – this results in bone inflammation. The body is no longer able to expel the great number of bacteria and the inflammation grows.

The progress of the disease depends on various factors:

access by the immune system

immune status of the patient

type, quantity and aggressiveness of the cause of the inflammation

local factors (e.g. tooth anatomy)

These various factors account for the various types of tooth-ache – pulsing, pressing, dull, difficult to locate, etc. There are no definite boundaries between these reactions, there may also be many combinations, many may only occur years later. One should always remember that every patient feels pain differently.

The dentist knows what needs to be done: all teeth which are filed down or contain fillings need to be checked for vitality twice a year – this is done using a cold spray. If the cold sensation is negative – you feel nothing – (a dentist calls this „insensitivity“), this may be a sign that the dental nerve has suffered damage, as a healthy nerve passes on the sensation of cold. The intensity of the sensation does not matter, even a little bit amounts to „passing on“.

However, if the sensation lasts very long – even when the cold stimulant is gone - this may be a sign of acute nerve inflammation.

If nothing is felt, then x-rays should be taken. If these also show changes, a „dead“ dental nerve may be assumed, then root treatment should be performed on the tooth, as it is devital and thus a threat to the body.

Why is it a threat? Well, every inflammatory reaction puts a strain on our immune system, the body has to „work“ constantly. Even if you have no pain and do not even realize there is an inflammation. Moreover, if there is an inflammation center, this could cause bacteria to spread out. These „wandering bacteria“ like to settle in places where they can avoid the immune system – for example materials not native to the body (such as implants, artificial heart valves, and so on), parts of the body with poor circulation (such as the extremities of diabetics,…) or good breeding grounds (blood clots – thromboses, and so on).

These „dispersed“ bacteria cause damage through local inflammatory reactions. Whatever the causes, each of these centers should be cleaned – by means of a root treatment!