PULP SENSIBILITY AND MASSETER INHIBITORY REFLEX IN DIABETIC POLYNEUROPATHY

Trial statusNot yet recruiting
Trial phaseNot listed
Trial typeObservational
Biological sexAll
Age25-65
SponsorBezmialem Vakif University

About this trial

Accurate evaluation of dental pulp health is essential to avoid unnecessary endodontic treatments. In routine dental practice, pulp sensibility is commonly assessed using electric pulp testing and thermal (cold) testing. However, these tests depend on patient perception and may be influenced by various factors such as systemic diseases, nerve damage, anxiety, trauma, or medication use.

Diabetic polyneuropathy is a common complication of diabetes mellitus and may alter peripheral nerve function, potentially affecting dental pulp sensibility test responses. This clinical study aims to evaluate how the severity of diabetic polyneuropathy influences dental pulp sensibility responses and masseter inhibitory reflex (MIR) parameters. The MIR is an objective neurophysiological reflex that allows quantitative assessment of trigeminal nerve function.

In this study, individuals with mild diabetic polyneuropathy, severe diabetic polyneuropathy, and healthy controls will be evaluated. All participants will undergo electric pulp testing, cold testing, and MIR measurements using standardized protocols.

The primary hypothesis of this study is that increasing severity of diabetic polyneuropathy leads to reduced dental pulp sensibility responses and altered MIR parameters compared to healthy individuals. It is further hypothesized that conventional pulp sensibility tests may produce false-negative results in patients with advanced neuropathy.

The findings of this study are expected to contribute to more accurate endodontic diagnosis and improved understanding of orofacial neurophysiological changes in diabetic patients.

Eligibility criteria

This trial accepts healthy volunteers

Qualifiers

Diagnosis of diabetic polyneuropathy confirmed by a neurologist

Neuropathy severity (mild or severe) determined by nerve conduction studies

No history of diabetes mellitus

No history of peripheral neuropathy or neurological disease

Disqualifiers

History of chemotherapy, head and neck radiotherapy, or systemic conditions known to affect peripheral nerve function (other than diabetic polyneuropathy in the patient groups)

Presence of acute or chronic orofacial pain disorders

Use of medications within the last 24 hours that may affect sensory perception or nerve conduction (e.g., analgesics, sedatives, neuroactive drugs)

History of trauma to the maxillary central incisor or surrounding tissues

Trial population

Study participants will be selected from adult patients attending the Departments of Neurology and Endodontics at Bezmialem Vakif University. The study population will include individuals diagnosed with type 2 diabetes mellitus with mild and severe diabetic neuropathy who have been evaluated in the Neurology Department, as well as systemically healthy control subjects. Participants will be recruited from patients referred from the Neurology Department and from individuals presenting for routine dental examination at the university dental clinic.

Trial design

Design model

Cohort

Time perspective

Prospective

Treatments tested in this trial

Not listed

Trial groups

108 Participants
are grouped into 3 trial groups
Group A: Mild Diabetic Polyneuropathy
Group B: Severe Diabetic Polyneuropathy
Group C: Healthy Controls Group

Trial outcomes

Primary outcomes

1

Electrical Pulp Testing Threshold

Electric pulp sensibility will be evaluated using a standardized electric pulp test (EPT) performed on the maxillary central incisor. The tooth will be isolated and dried, and a conductive medium will be applied to ensure proper electrical contact. The EPT probe will be placed on the mid-facial surface of the tooth, and electrical stimulus intensity will be gradually increased according to the manufacturer's instructions. Participants will be instructed to indicate the first sensation perceived during stimulation. The stimulus will be stopped immediately upon participant response. The response threshold will be recorded as a numerical value on a standardized scale ranging from 0 to 64. The test will be repeated after a short recovery period if necessary to confirm reproducibility.

Time frame
The total duration of the EPT procedure is expected to be approximately 2-3 minutes per participant, including tooth isolation, probe placement, gradual increase of electrical stimulus intensity, and recording of the response threshold.

Secondary outcomes

1

Time to First Sensation During Thermal (cold) Pulp Sensibility Test

Thermal (cold) pulp sensibility will be assessed using a standardized cold test performed on the maxillary central incisor. The tooth will be isolated and dried, and a cold stimulus will be applied to the mid-facial surface using a cotton pellet sprayed with refrigerant (e.g., 1,1,1,2-tetrafluoroethane). The stimulus will be maintained until the participant reports the first sensation. The test will be repeated after an appropriate recovery period to avoid sensitization. The time to first sensation will be recorded in seconds (s).

Time frame
The thermal (cold) pulp sensibility test will require approximately 2-3 minutes, including tooth isolation, application of the cold stimulus, and recording of response times.
2

Time to Disappearance of Sensation After Thermal (cold) Stimulus Removal

Using the same standardized cold test protocol, thermal (cold) pulp sensibility will be assessed on the maxillary central incisor. The tooth will be isolated and dried, and a cold stimulus will be applied to the mid-facial surface using a cotton pellet sprayed with refrigerant (e.g., 1,1,1,2-tetrafluoroethane). After the stimulus is removed, the time from removal of the cold stimulus to complete disappearance of the sensation will be recorded in seconds (s) to assess pulp sensibility recovery characteristics.

Time frame
The thermal (cold) pulp sensibility test will require approximately 2-3 minutes, including tooth isolation, application of the cold stimulus, and recording of response times.
3

Masseter Inhibitory Reflex Latency

The masseter inhibitory reflex (MIR) will be recorded using electromyography to objectively assess trigeminal nerve function. Participants will be seated in a comfortable position, and electromyographic electrodes will be placed according to standardized neurophysiological protocols. Electrical stimulation will be delivered to the maxillary central incisor using a sterile needle electrode. The stimulation intensity will be set at 120% of the individual electric pulp test (EPT) sensory threshold. During stimulation, electromyographic activity of the masseter muscle will be recorded, and the latency of the silent periods (SP1 and SP2) will be measured in milliseconds (ms).

Time frame
The total duration of MIR recording, including electrode placement, calibration, and electromyographic data acquisition, is expected to be approximately 10-15 minutes per participant.
4

Masseter Inhibitory Reflex Silent Period Duration

Using a standardized electromyographic recording protocol, the masseter inhibitory reflex will be recorded to assess trigeminal nerve function. Participants will be seated in a comfortable position, and surface electromyographic electrodes will be placed over the masseter muscle according to established neurophysiological guidelines. Electrical stimulation will be delivered to the maxillary central incisor using a sterile needle electrode. The stimulation intensity will be set at 120% of the individual electric pulp test (EPT) sensory threshold. Following stimulation, the duration of the silent periods (SP1 and SP2) will be measured in milliseconds (ms) to assess inhibitory trigeminal reflex function.

Time frame
The total duration of MIR recording, including electrode placement, calibration, and electromyographic data acquisition, is expected to be approximately 10-15 minutes per participant.

Other outcomes

Locations

This trial has no locations.

Sponsors and contacts

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