General principles of action of the physical factors

This topic covers the general principles on which all physical therapeutic factors in dental physiotherapy rest: the aim of physiotherapy, the physical diagnostic tests used in dentistry, how physical energy acts on the body, the mechanisms by which it does so, and the eight principles that govern its safe and effective use.

The word physiotherapy comes from the Greek fysis, meaning nature, so physiotherapy is therapy by natural and preformed factors. The aim of physiotherapy in general is to restore health through these physical factors, rather than through drugs or surgery.

Before any physical factor is used, the tooth and pulp are examined with physical diagnostic tests. In dental physiotherapy these include:

1. Thermodiagnostics: hot and cold tests of the tooth (hot gutta-percha, cold ethyl chloride and ice block).
2. Electric pulp test (EPT): examines the innervation of the pulp by electrical stimulation.
3. Pulse oximetry (PO): measures the saturation of blood in the blood vessels of the pulp.
4. Infrared thermography (IRT): records the temperature of the body as a heat picture, without contact.

The first two tests examine the nerves of the pulp, and pulse oximetry examines its blood vessels. Each is described in its own topic.

Physical energy joins the energetic processes of the organism. Its effects follow three main lines:

Physical factors influence the organism through three mechanisms, which often act together:

• Neuroreflex mechanismthe factor acts on nerve endings, and the response travels along nerve pathways as a reflex.
• Neurohumoral mechanismthe factor triggers a response of the organism through chemical messengers carried in the body fluids.
• Neuroendocrine mechanismthe factor acts through the nervous system on the hormone-producing glands.

Eight principles guide the choice and use of every physical factor:

1. Correct diagnosis. The diagnosis must be complete and precise, because it decides which physical factor can help. Treatment is not given to a patient whose diagnosis is unclear, since this can cause serious harm.
2. Individual assessment. The initial state of the patient and their general reactivity are assessed. The stage of the disease decides when treatment should start. Dental physiotherapy is used mainly in the chronic stage of a disease.
3. Clear aim. The aim of each procedure must be defined. It may be to influence the cause of the disease (aetiology), its development (pathogenesis) or the pathological process itself.
4. Differentiated choice. The factor and the method of application are chosen with care. The same nosological unit may be treated with different physical factors to obtain different effects, although some effects are specific to one factor.
5. Prevention of overdosing. The parameters of the factor must suit the age, weight and condition of the patient and the stage of the disease.
6. Individual response (systemic medical suspension of the patient's responses). Sometimes the organism does not react as expected to the chosen factor. In that case the factor or its parameters are changed.
7. Combination of factors. Factors with specific effects and factors with common effects may be combined.
8. Sequence. One or several physical factors may be applied in a set order, and treatment is given as a course of procedures.

• Diagnosis firstno physical factor without a complete and precise diagnosis.
• Three mechanismsneuroreflex, neurohumoral, neuroendocrine.