Iontophoresis and topical application of 8% arginine-calcium carbonate to treat dentinal hypersensitivity

Effect of Iontophoresis on the Effectiveness of Nano-Hydroxyapatite and Pro-argin in In-Office Treatment of Dentin Hypersensitivity: A Split-Mouth Randomized Clinical Trial

Background and objectives Dentin hypersensitivity (DH) treatment is one of the main challenges dentists face in their daily clinical practice. Current therapies provide only temporary relief and require multiple applications to exhibit results, and there is a lack of evidence related to the long-term effects of these agents. Nano-hydroxyapatite (n-HA) and pro-argin (8.0% arginine-calcium carbonate) have recently been used for dentin desensitization with a one-time in-office application, but the effects are interim. However, a standard treatment protocol demands definitive or enduring results. Since iontophoresis amplifies the transport of neutral and ionized drugs across a membrane, the use of these desensitizing agents with iontophoresis may be beneficial to accomplish satisfactory results. This study was conducted to evaluate whether iontophoresis could enable better penetration of nano-hydroxyapatite and pro-argin into the dentin, enhancing and prolonging their therapeutic effect. Materials and methods Forty-five participants with dentin hypersensitivity in the age group of 20 to 60 years were included. In each individual, four teeth with cervical lesions (one from each quadrant) were selected and divided randomly into four groups: group I: desensitizing paste containing nano-hydroxyapatite, group II: desensitizing paste containing nano-hydroxyapatite with iontophoresis, group III: desensitizing paste containing pro-argin, and group IV: desensitizing paste containing pro-argin with iontophoresis; followed by one-time application of the agents. Sensitivity was assessed by tactile, air blast, and cold-graded thermal tests (CGTTs) before and immediately after application, after one week, and at the end of the first, third, and sixth months. Statistical analysis Statistical analysis was done by repeated measures ANOVA for within-group comparison. Intergroup comparison was done using one-way ANOVA and Tukey's post-hoc test. Results All the groups showed a statistically significant reduction in dentin hypersensitivity (p<0.001). The reduction in hypersensitivity in various groups can be graded as group II (3.578/1.800/1.556) > group IV (3.367/1.755/1.555) > group I (2.3781/1.022/0.822) > group III (2.222/0.911/0.778) as evaluated by tactile, air blast, and cold-graded thermal tests, respectively. Group II and group IV presented a significant reduction in sensitivity levels consistent for up to six months. Conclusion Nano-hydroxyapatite and pro-argin can be used effectively for reducing dentin hypersensitivity. Iontophoresis can be a valuable adjunct for their improved delivery, enhancing and prolonging their effectiveness.

Iontophoresis application for drug delivery in high resistivity membranes: nails and teeth

Iontophoresis has been vastly explored to improve drug permeation, mainly for transdermal delivery. Despite the skin's electrical resistance and barrier properties, it has a relatively high aqueous content and is permeable to many drugs. In contrast, nails and teeth are accessible structures for target drug delivery but possess low water content compared to the skin and impose significant barriers to drug permeation. Common diseases of these sites, such as nail onychomycosis and endodontic microbial infections that reach inaccessible regions for mechanical removal, often depend on time-consuming and ineffective treatments relying on drug's passive permeation. Iontophoresis application in nail and teeth structures may be a safe and effective way to improve drug transport across the nail and drug distribution through dental structures, making treatments more effective and comfortable for patients. Here, we provide an overview of iontophoresis applications in these "hard tissues," considering specificities such as their high electrical resistivity. Iontophoresis presents a promising option to enhance drug permeation through the nail and dental tissues, and further developments in these areas could lead to widespread clinical use.

The Challenge in Combining Pelotherapy and Electrotherapy (Iontophoresis) in One Single Therapeutic Modality

Pelotherapy and electrotherapy are therapeutic methodologies with proven success in physical medicine and rehabilitation (PMR) and dermatology fields. The main purpose of these therapeutic modalities is to reduce pain, accelerate wound healing, alleviate muscle spasms, and improve mobility, and muscle tone. Their main challenge is in the passage of some ionic species through the skin barrier. The use of drugs, such as diclofenac, corticosteroids or steroids, has gained widespread efficacy recognition in physical therapy and the therapeutic action of these drugs is widely studied in experimental and clinical trials. Unlike pharmaceutical and cosmetic clays, peloids are not subject to any prior quality control or subject to any specific European regulation. The dermal absorption values are an integral part of the risk assessment process for peloids. This work explores the converging points between these two transdermal drug delivery systems (TDDS) and the presentation of methodologies to achieve peloid safety compliance, especially concerning the potential and degree of toxicity arising from ion exchange and trace elements. TDDS is applied to the pharmaceuticals industry and drug is the generic term for the active substances released into skin tissues. The transdermal delivery of drugs or clay components with therapeutic properties is limited due to the excellent barrier function of the stratum corneum. The transdermal drug delivery of pelotherapy is enhanced by temperature and electrically by iontophoresis. The low voltage of iontophoresis and sweat phenomena with pore dilation driven by pelotherapy allows the use of the same pathways: hair follicles and sweat pore. The therapeutic integration of iontophoresis and pelotherapy focused on patient benefits and low safety-related risk may contribute to the outstanding physiological performance of pelotherapy, specifically, in the way the essential elements and exchange cations pass through the skin barrier. The validation of an innovative iontophoretic systems applied to pelotherapy can also promote future challenges in the obtaining of the ideal therapeutic control of peloids and the clinical validation of results with physiological efficacy recognition.

Effect of a dentifrice containing different particle sizes of hydroxyapatite on dentin tubule occlusion and aqueous Cr (VI) sorption

Background

Dentin hypersensitivity is a common negative oral condition that can be treated with dentifrice containing hydroxyapatite (HA). The study evaluated the effect of nano-HA dentifrice on plugging the dentinal tubules for an anti-sensitivity reaction compared to a dentifrice containing common-sized particles. Also, the adsorption capacity of different particle sizes of HA mixed in a dentifrice and which is the optimal particle size was considered.

Methods

Fourty premolar dentine discs and fourty molar dentine discs were randomly divided into 4 groups: distilled water group, ordinary dentifrice group and 80, 300 nm HA dentifrice group. Each dentin disc was brushed with a dentifrice twice daily at 7600 rpm under 100 g force for 2 mins for 7 consecutive days and divided into two parts, half of the dentin disc was detected by the scanning electron microscope (SEM) and energy dispersive spectrometer (EDS), the other half was brushed with distilled water and observed by SEM. One milliliter dentifrice solution (80 nm HA dentifrice, 300 nm HA dentifrice, ordinary dentifrice) was added to 50 ml potassium dichromate solution for 1, 14, and 28 d. The residual Chromium (Cr⁶⁺) concentration in the supernatant was measured by the diphenylcarbon phthalocyanine hydrazine method. The elemental constitution in the precipitate was detected by EDS. The Kruskal-Wallis test was used to analyze surface mineralization and different plugging rates of dentinal tubules. The absorption capacity of dentifrices were also evaluated by the Kruskal-Wallis test.

Results

The plugging rate in the HA dentifrice group was higher than that in the ordinary dentifrice group, and the 80 nm HA dentifrice group showed the best result. The atomic percentages of Ca and P of 80 nm dentifrice group on the surface of dentinal tubules were the highest. The 80 nm HA dentifrice group showed the best adsorption and stable effect of Cr⁶⁺, followed by the 300 nm HA dentifrice group. The 300 nm HA dentifrice and the ordinary dentifrice showed desorption phenomenon.

Conclusions

The dentifrice containing HA, especially the 80 nm HA dentifrice, exerts good dentinal tubule occlusion and surface mineralization effect. This dentifrice was also a good adsorbent of Cr⁶⁺.