HYDROFLUORIC ACID QUANTIFICATION IN PORCELAIN CONDITIONING GEL SAMPLES USING HIGH RESOLUTION CONTINNUM SOURCE MOLECULAR ABSORPTION SPECTROMETRY BY CaF

Dental ceramics are frequently used in odontology because of their ability to mimic the function and esthetics of dental tissues, also the biocompatibility, color stability, high mechanical strength, radiopacity and low thermal conductivity¹. Therefore, it is necessary to perform the conditioning of the ceramic, this is normaly done using the porcelain conditioning gel to favor adhesion to the resin cement, thereby reducing the angle of contact between the materials. The materials used in this gels are silane and hydrofluoric acid². Hydrofluoric acid, in turn, deserves attention because of its toxicity and high corrosivity, since exposure time and its concentration can cause serious injury when in contact with the skin and mucous membranes. This work aimed to quantify the HF in commercial porcelain conditioning gel with different concentrations of HF, 5%, 10% and 15% using high resolution molecular absorption spectrometry with continuous source (HR-CS MAS) by the CaF molecule. Studies of the thermal behavior of the CaF molecule in the dental gels matrix and the aqueous medium through pyrolysis and vaporization curves were performed at wavelength 606.4322 nm. It was established as optimal temperatures 1000 º C and 2300 º C for pyrolysis and vaporization, respectively. It was not necessary to use chemical modifier. A study was conducted to compare the stability of commercially available buffered and unbuffered dental gels. The determination of HF concentration was applied for six different samples with marked concentrations of 5%, 10% and 15% HF. The buffered samples were stable with time. Addition and recovery tests were performed to evaluate the accuracy of the method and the recovery values obtained were between 89% and 105%.