Comparative Efficacy of Iontophoresis with APF Gel and Iontophoresis with Commercially Available Toothpastes (Elsenz^® and Perfora) in the Management of Dentinal Hypersensitivity - A 3 months Follow-Up randomized Controlled Trial

Study design

A total of 27 patients with tooth sensitivity were selected from the outpatient department of Periodontics, Manipal College of Dental Sciences, Mangalore. The study involved a single examiner, and selected patients were randomly assigned to one of the three treatment modalities via computerized block randomization prior to the procedure. The entire sample size was divided into three blocks via sealed envelope software. The parallel group design lasted 3 months, after the study protocol was approved by the Ethics Committee of Manipal University, which was conducted in accordance with the Helsinki Declaration of 1975, as revised in 2013. The study adhered to the Consolidated Standards of Reporting Trials (CONSORT) 2010 guidelines for randomized clinical trials ( Figure 1). This study is listed with the Clinical Trials Registry-India (CTRI) under registration number CTRI/2025/09/095193 (https://ctri.nic.in/Clinicaltrials/rmaindet.php?trialid=110356&EncHid=37835.53169&modid=1&compid=19).

Figure 1. CONSORT flow diagram for participant recruitment, allocation, follow-up, and analysis.

Figure 2. a) Perfora Sensitive Toothpaste b) Fluorotop APF Gel c) Elsenz^® Toothpaste d) iontophoresis unit with e) iontophoresis unit tip f ) sponge g) plastic tray with metal plate.

Systemically healthy patients having plaque and gingival index less than 20%¹² and complain of hypersensitivity to thermal, mechanical, sweet, or sour stimuli on the facial or lingual surfaces of teeth were divided into 3 groups. (n = 9 per group) using computer-based block randomization. Allocation was concealed using sealed envelopes prepared prior to the surgical appointments. All the patients who expressed their willingness to participate in the study signed the informed consent prior to commencement of the study.

Group 1: Elsenz^® toothpaste with iontophoresis

Group 2: Perfora toothpaste with iontophoresis

Group 3: Fluorotop APF gel with iontophoresis

Inclusion and exclusion criteria

Adults of both gender, aged 18–65 years, who were systemically healthy and presented with hypersensitivity to thermal, mechanical, sweet, or sour stimuli on the facial or lingual surfaces of teeth were included. The patients who have undergone active periodontal treatment within the last six months, pregnant or lactating females, individuals already under treatment for dentinal hypersensitivity (DH), those with known allergies or pacemakers, and patients with sensitivity related to GERD (Gastroesophageal reflux disease) Individuals with medical, psychiatric, or pharmacological histories that could compromise the study; systemic conditions predisposing them to DH (including eating disorders); and those with orthodontic appliances or fixed prostheses that may interfere with DH evaluation were excluded. Based on the criteria mentioned selected patients were enrolled and randomized into three treatment groups and provided one of the following treatments.

Clinical evaluation

Clinical assessment for DH was carried out using tactile test (Figure 3) and air blast test (Schiff Cold Air Sensitivity Scale test) (Figure 4). The tooth under interest was isolated and the two tests were performed. The tactile test was done first to all subjects which was followed by air blast test. A minimum interval of 5 mins was maintained between the two tests. A sterile dental explorer was gently run across the affected surface of tooth and subject’s response was recorded. After five minutes air blast test was conducted using a 3-way dental syringe for a duration of 1 second per tooth.

Figure 3. Assessment of tactile sensitivity using dental explorer.

Figure 4. Air blast test using three-way syringe.

Sensitivity assessment

The subject responses were recorded using visual analogue scale (VAS), a method which assesses a characteristic attitude that is believed to range across a continuum of values and cannot be easily objectively measured. It is a line of 10 cm in length, the extreme of a line representing the limits of pain a patient might experience from an external stimulus.

The study participants were asked to record their overall sensitivity by marking a point on a 10-cm VAS, where 0 indicated no pain and 10 indicated unbearable pain experienced due to a blast of air, cold water application, and tactile stimuli. Once the DH assessment was done this was followed by the treatment based on the allotted treatment arm.

All the participants underwent supragingival scaling and polishing and personalized tailor-made oral hygiene instructions were given by a single examiner. To maintain uniformity all patients were provided with a new ultrasoft bristle toothbrush. Each subject was requested to brush twice daily using provided toothbrush and toothpaste.

Procedure

The isolation of the affected area was achieved using sterile cotton rolls. This was followed by application of allocated toothpaste with iontophoresis. In group 1 Elsenz^®, group 2 Perfora and in group 3 APF gel were applied and iontophoresis activated.

— Elsenz^® toothpaste (Group 1), Perfora toothpaste (Group 2) or Fluorotop APF gel (Group 3), a thin layer of the corresponding desensitizing agents were applied to the affected area via sponge and the sponge was supported by a metal plate embedded into the plastic tray, which was positioned to maintain direct contact with the surfaces of the affected teeth and to ensure even dispersion of the low-intensity electric current throughout the arch and appropriate placement of the agent within the oral cavity. The patient held the passive electrode, which was identified by a red spiral cord, while the electrode spoon attached to the black spiral cable was placed in the patient’s mouth above the sponge to finish the circuit. To maximize the therapeutic effect, the iontophoresis machine was turned on, and the current was progressively increased from 0.5 mA to a maximum of 2.5 mA until the patient felt some degree of sensitivity. The duration of each session was two minutes. Upon completion, the electrode spoon and sponge were removed, and the device was shut off. To analyze both immediate and delayed reactions, sensitivity was measured via tactile and air-blast tests. Scores were recorded at baseline, immediately after treatment and during follow-up visits after two weeks, 1 month and 3 months. The procedure was repeated if the sensitivity persisted at the second visit. Patients were instructed to use the same desensitizing toothpaste as prescribed during the follow-up period (Figure 5).

Figure 5. Performing iontophoresis therapy, applying a desensitizing agent with a sponge-supported tray with metal plate in the patient’s mouth.

Dentinal hypersensitivity scores ( Table 1)

The air blast and tactile tests were used to evaluate the dentinal hypersensitivity of a total of 27 participants (9 per group; 14 females, 13 men). There were no discernible variations in air blast sensitivity between the groups at baseline (p = 0.288). Group 1 (Elsenz^® + iontophoresis) improved from 7.33 to 2.56 (mean diff. = 4.78, p < 0.001) and then to 0.56 after a second application (mean diff. = 1.89, p < 0.001), whereas Group 2 (Perfora + iontophoresis) demonstrated the largest reduction in air blast scores from 8.11 to 0.56 (mean diff. = 7.56, p < 0.001) without needing a second treatment. At two weeks, Group 3 (APF gel + iontophoresis) decreased from 2.89 to 0.78 (mean diff. = 2.11, p < 0.001) and from 7.44 to 3.11 (mean diff. = 4.33, p < 0.001), indicating lower long-term effectiveness.

Group 2 once more demonstrated the fastest and most thorough decrease from 4.0 to 0.0 (mean diff. = 4.0, p < 0.001) for tactile sensitivity, even though starting scores were not statistically different (p = 0.403). Group 3 dropped from 3.67 to 1.22 (mean diff. = 2.44, p < 0.001) and from 1.83 to 0 in two weeks (mean diff. = 1.83, p = 0.006), but Group 1 improved from 3.56 to 0.67 (mean diff. = 2.89, p < 0.001). Overall group differences remained significant (p = 0.029), despite two-week subgroup tactile differences not being statistically significant (p = 0.518). While Group 1 exhibited steady progress with repeated application and Group 3 showed fewer permanent outcomes, Group 2 collectively showed the most effective and long-lasting desensitizing outcome in both assessments, without the need for retreatment indicating a need for more frequent reapplication.

Limitations and future aspects

This study has certain limitations, even with the encouraging results. The findings may not be as broadly applicable due to the limited sample size of 27 individuals and the single-center design, and the three-month follow-up period limits the assessment of long-term efficacy and dentinal hypersensitivity recurrence. Because the sole examiner was not blinded, observer bias may have been incorporated into the subjective VAS scores used for pain evaluation. Furthermore, there was insufficient monitoring of patient compliance with dental hygiene guidelines, and neither radiographic nor microscopic verification of dentinal tubule occlusion was carried out. Future studies should examine the durability of desensitization using bigger, multi-center trials with longer follow-up times. Together with patient-reported results, objective assessment techniques like laser Doppler flowmetry, confocal microscopy, or scanning electron microscopy would offer a more thorough picture of therapy effectiveness. Moreover, iontophoresis-assisted desensitizing agents may be further optimized in clinical settings and long-term management of dentinal hypersensitivity may be enhanced by comparison with other modern interventions, the use of double-blind study designs, and investigation of formulation factors such as flavor, texture, and bioactive components.