Key factors in pulp testing are the enamel and dentine thickness, and the number of nerve fibers in the underlying the pulp. EPT is not used in patients with orthodontic bands or crowned teeth, as the current may be conducted to adjacent teeth, resulting in false-positive responses. Pulp nerve fibers also respond to lower current intensities and only a small number of pulpal nerves are required to create responses when electrical stimulation is applied. This means that EPT may result in false-positive responses in teeth with pulpal necrosis. Furthermore, as pulpal and periodontal nerve thresholds overlap, the periodontal nerves may give a false indication of tooth sensibility.Possible explanations for false-positives include:

Response caused by conduction of the current because of periodontal or gingival issues
Breakdown products associated with pulp necrosis may be able to conduct electric current next to infected and hypersensitive pulp tissue
Inflamed pulp tissue may still be present
Metallic restorations or orthodontic gear are still presentStudies have indicated that there is little correlation between histopathological status of the pulp and clinical information. A negative EPT response showed localized necrosis in 25.7% of cases and 72% of cases. Thus, 97.7% of cases with a negative response to EPT indicated that a root canal treatment should be carried out. Test cavity: The preparation of a test cavity involves cutting into the dentine of a tooth to determine whether the sensory element of the pulp is still functioning. Test cavity preparation is a last resort as this method is considered invasive and irreversible.
Psychasthenia was a psychological disorder characterized by phobias, obsessions, compulsions, or excessive anxiety. The term is no longer in psychiatric diagnostic use, although it still forms one of the ten clinical subscales of the popular self-report personality inventories MMPI and MMPI-2. Signs and symptoms
The MMPI subscale 7 describes psychasthenia as akin to obsessive-compulsive disorder, and as characterised by excessive doubts, compulsions, obsessions, and unreasonable fears. The psychasthenic has an inability to resist specific actions or thoughts, regardless of their maladaptive nature. In addition to obsessive-compulsive features, the scale taps abnormal fears, self-criticism, difficulties in concentration, and guilt feelings. The scale assesses long-term (trait) anxiety, although it is somewhat responsive to situational stress as well. The psychasthenic has insufficient control over their conscious thinking and memory, sometimes wandering aimlessly and/or forgetting what they were doing. Thoughts can be scattered and take significant effort to organize, often resulting in sentences that do not come out as intended, therefore making little sense to others. The constant mental effort and characteristic insomnia induces fatigue, which worsens the condition. Symptoms can possibly be greatly reduced with concentration exercises and therapy, depending on whether the condition is psychological or biological. History
The term "psychasthenia" is historically associated primarily with the work of Pierre Janet, who divided the neuroses into the psychasthenias and the hysterias, discarding the term "neurasthenia" since it implied a neurological theory where none existed.