Ax 200

The uniform and pitting corrosion rates were determined following the guidelines of the NACE RP 0775 [18 ] standard. It is noteworthy that the uniform corrosion rate was determined by the mass loss technique, using a scale model AX200 SHIMADZU, Tokyo, Japan, with a precision of four decimal digits, while the pitting rate took into account the deepest pit developed in the material structure according to the exposure time in the corrosive medium. Both rates were determined in mm/year according to the Equations (1) (uniform) and (2) (pitting), provided as follows: $$CR=\frac{W\ast 365\ast 1000}{\begin{array}{c}ATD\\ \end{array}}$$
where:
CR = average corrosion rate, millimeters per year (mm /year);
W = mass loss, grams (g);
A = initial exposed area of the coupon, square (millimeters (mm²);
T = exposure time, days (d);
D = coupon metal density, grams per cubic centimeter (g/cm³).
$$\mathrm{P}\mathrm{R}(\mathrm{m}\mathrm{m}/\mathrm{a}\mathrm{n}\mathrm{o})=\frac{Depthofdeepestpit\left(mm\right)\ast 365}{\mathrm{e}\mathrm{x}\mathrm{p}\mathrm{o}\mathrm{s}\mathrm{u}\mathrm{r}\mathrm{e}\mathrm{t}\mathrm{i}\mathrm{m}\mathrm{e}\left(\mathrm{d}\mathrm{a}\mathrm{y}\mathrm{s}\right)}$$

Each formulated patch was independently weighed using an analytical balance (Shimadzu AX 200, Kyoto, Japan) to determine weight uniformity. Following that, the weight of each patch was compared to the average weight [26 (link)].

ICP-AES experimental procedures were conducted according to Malkoc et al. [14 (link), 15 (link)] and Secilmis et al. [16 (link)].
All dentin slabs (n = 34 per group) were stored at 70°C in cabinet desiccators (Ventisell, Italy) until they reached a constant weight. Then each specimen was weighed on an electronic balance (AX200; Shimadzu Corporation, Kyoto, Japan) and the weight was recorded [14 (link)]. Nitric acid (10 mL) and hydrochloric acid (3 mL) were added onto the specimens and they were digested in a microwave reaction system (Mars 5; CEM, Matthews, NC) at 180°C and 180 psi [16 (link)].
After calibration of the ICP-AES instrument (Vista AX, Varian, Mulgrave, Australia), 2 mL of solution was taken. The solutions are carried in a nebulizer with the help of a peristaltic pump. The specimen is turned into an aerosol which is carried by an argon spray. The aerosol is heated by conduction and radiation and reaches approximately 10,000°C. Light is transferred to a detector, and every element is evaluated according to its wavelength. Five measurements were performed on each element for each solution, and the means of the measurements were calculated in milligrams per liter (parts per million) [15 (link), 16 (link)]. The levels of Ca, K, Mg, Na, and P in each specimen were determined, and the mineral contents were then calculated as percentage by weight.

Analytical weighing balance (Shimadzu AX 200, Kyoto, Japan, +81-75-823-1111) was used for the investigation of weight variations in between formulated patches. The data obtained was averaged for confirming weight variation values [16 (link)].

Nanoparticles loaded patches were prepared using solvent casting technique. Ethyl cellulose was used as patch forming polymer. Polymer and excipients were weighed precisely using analytical balance (Shimadzu AX 200, Kyoto, Japan) and dissolved in the solvent system (comprised of equal amount of 10 mL of ethanol and distilled water) using magnetic stirrer. The prepared nanoparticles were suspended in distilled water. The NPs aqueous phase was added to the polymer solution under continuous stirring. PEG-400 was added as plasticizer. The solution was sonicated using sonicator (D-78224, Singen, Germany) and carefully poured into petri-dishes. The Petri dishes were dried in oven in dark and at 37 °C temperature. The final prepared patches were kept in desiccator until further use [26 (link)].