Neurological Responses in Patients with Dentine Hypersensitivity

Dentine hypersensitivity (also known as sensitive teeth) is a common dental condition in which the dentine, a layer of sensitive hard tissue under the enamel of the teeth, becomes exposed making the teeth sensitive to stimuli, such as hot and cold. It poses a significant challenge for clinicians and affects patients' quality of life.

The overall aim of the study is to understand if a way of measuring brain activity (electroencephalography \[EEG\]) shows a response to tooth stimulation, and see how these responses may be different in patients with dentine sensitivity.

EEG records brain signals and can provide information about how the brain processes painful stimuli. EEG recording is a non-evasive and painless procedure. It involves using a cap with small sensors called electrodes to pick up brain signals. During the EEG assessment appointment, brain signals will be recorded throughout the duration when cold temperatures and short bursts of air are applied to the tooth. Brain signals recorded during tooth stimulation from participants with and without dentine sensitivity will then be compared to explore if there are any differences.

The investigators hope that EEG responses could be helpful to objectively assess dentine sensitivity, further the understanding of brain processing of dental pain, and allow the comparison of the effectiveness of different treatment options in the future.

This information may help to improve treatments and the quality of life for patients with dentine sensitivity and potentially other types of dental pain.

Dentine hypersensitivity (DH) is a common dental condition that has been defined as a 'short, sharp pain arising from exposed dentine in response to stimuli typically thermal, evaporative, tactile, osmotic or chemical and which cannot be ascribed to any other form of dental defect or pathology'. Many DH interventions have been investigated over the last 60 years, but a lack of standardisation of pain measurement and objectivity of measures are major limitations for assessing the efficacy of products (or understanding why products fail). A potential solution to this problem is greater understanding of the pain propagation mechanism from controlled stimulus to objective, measurable markers of pain severity.

EEG (electroencephalography) is a non-invasive technique that measures the electrical activity of the brain using the electrodes placed on the scalp. EEG provides information about the brain's electrical activity over time, helping diagnose and understand certain neurological conditions. The investigators have carried out a number of studies using human dental pulp and other human tissue to further understand the mechanisms of pain including pulpal pain.

Evoked potentials are EEG responses to specific stimuli, such as light, sound or heat. Pain-evoked potentials from tooth pulp are evoked potentials specifically related to pain originating from the pulp of a tooth. This type of measurement records the brain's electrical response to a stimulus applied to a tooth, such as thermal stimuli. The resulting EEG recording can provide information about how the central nervous system processes painful stimuli, including the speed and magnitude of the response. It was hypothesised that EEG pain-evoked potentials, if generated and measured in a controlled and repeatable way, can potentially be used (in conjunction with other diagnostic methods) to objectively evaluate the severity of dentine sensitivity and compare the efficacy of different treatment options.

Eligibility Criteria:
Inclusion Criteria:

1. Adults 18 years and older;
2. Understands and is willing, able and likely to comply with all study procedures and restrictions;
3. Accepts the form of the study and signs a declaration of informed consent;
4. In good health (in the opinion of the clinical dental professional);
5. A minimum of 10 teeth not including teeth with crowns or bridges from upper right 4 to upper left 4 and lower right 4 to lower left 4;

For patients with dentine sensitivity only (experimental group): self-reported sensitivity in at least 1 tooth; confirmed by response to air puff.

Exclusion Criteria:

1. Adults currently using maxillary or mandibular orthodontic appliances;
2. Obvious signs of untreated caries, which in the opinion of the clinical dental professional, will affect the scientific validity of the study;
3. Periodontal pocket depth ≥4mm in the anterior upper or lower sextants;
4. Evidence of periodontitis.
5. Have a history of seizures;
6. Taking medications that affect brain responses;
7. Experience damaged skin on the scalp due to cuts, psoriasis, eczema, or other conditions;
8. Any participant who in the investigator's judgment will not comply with the study protocol;
9. Any participant who has difficulties in adequate understanding of English.