Existing cavities must also be treated, as cavities that extend into the tooth cannot be effectively treated by teeth cleaning alone, and are at a high risk of spreading into the pulp of the tooth, leading to the loss of vitality and need for extraction or root canal therapy. This treatment regimen is the same as for all xerostomia patients, such as for those undergoing head and neck radiation therapy, which often damages the salivary glands; these glands are more susceptible to radiation than are other body tissues. Prognosis
Published studies on the survival of Sjögrens syndrome patients are limited in varied respects, perhaps owing to the relatively small sample sizes, and the fact that secondary Sjögrens syndrome is associated with other autoimmune diseases. Results from a number of studies indicate that, compared to other autoimmune diseases, Sjögrens syndrome is associated with a notably high incidence of malignant non-Hodgkin lymphoma, a cancer of white blood cells. About 5% of patients with SS develop some form of lymphoid malignancy. Patients with severe cases are much more likely to develop lymphomas than patients with mild or moderate cases. The most common lymphomas are salivary extranodal marginal zone B cell lymphomas (MALT lymphomas in the salivary glands) and diffuse large B-cell lymphoma.Lymphomagenesis in primary Sjögrens syndrome patients is considered as a multistep process, with the first step being chronic stimulation of autoimmune B cells, especially B cells that produce rheumatoid factor  at sites targeted by the disease.
In more basic organisms, the status of pain is the perception of the being stimulated, which is not observable although it may be shared (see gate control theory of pain). It is not proven that oysters can feel pain, but it is known that they react to irritants. When an irritating object becomes trapped within an oysters shell, it deposits layers of calcium carbonate (CaCO3), slowly increasing in size and producing a pearl. This is purely a defense mechanism, to trap a potentially threatening irritant such as a parasite inside its shell, or an attack from outside, injuring the mantle tissue. The oyster creates a pearl sac to seal off the irritation. It has also been observed that an amoeba avoids being prodded with a pin, but there is not enough evidence to suggest how much it feels this. Irritation is apparently the only universal sense shared by even single-celled creatures. It is postulated that most such beings also feel pain, but this is a projection – empathy. Some philosophers, notably René Descartes, denied it entirely, even for such higher mammals as dogs or primates like monkeys; Descartes considered intelligence a pre-requisite for the feeling of pain. Types
Eye irritation
Modern office work with use of office equipment has raised concerns about possible adverse health effects. Since the 1970s, reports have linked mucosal, skin, and general symptoms to work with self-copying paper. Emission of various particulate and volatile substances has been suggested as specific causes.