The Preventive And Remineralizing Effect Of Zinc-Carbonate Nano-Hydroxyapatite Versus Amorphous Calcium Phosphate-Stannous Fluoride On Enamel Of Primary Teeth

Abstract

This study was conducted to assess the the preventive and remineralizing efficacy of Zinc-Carbonate Nano-Hydroxyapatite (ZnCO3/n-Hap) versus Amorphous Calcium Phosphate-Stannous Fluoride (ACP-SnF) on enamel of primary teeth. The assessment was done using SEM/EDX, FTIR and microhardness. One hundred twenty recently exfoliated, caries-free primary anterior teeth were collected from the outpatient clinic, Pediatric Dentistry Department, Faculty of Dentistry, Ain Shams University. Teeth were extracted either for shedding or orthodontic reasons. Teeth were cleaned from organic debris and stored in deionized water until used. Teeth were carefully examined under good illumination (dental unit illumination) Tooth was excluded if any of the following was present: caries, discoloration, white/brown spot lesions, cracks, enamel defects and fluorosis. Acrylic blocks were fabricated with a 4*4mm window exposing the labial surface of each tooth. Test products were commercially available toothpastes with either ZnCO3/n-HAp or ACP-SnF as active ingredients. Dentifrice slurry was prepared in 3:1 ratio of deionized water to dentifrice. Dentifrice slurry, demineralizing and remineralizing solutions were freshly prepared before each pH cycle. The teeth were divided into two main groups according to the aim, Group A (remineralizing efficacy) and Group B (protective efficacy). The groups were further subdivided according to the tested agent used (ZnCO3/n-HAp, ACP-SnF and control). In each subgroup, 10 teeth were tested for mineral content change (SEM/EDX and FTIR) and 10 teeth were tested for microhardness. The mineral content was assessed by SEM/EDX, (where it measured the Calcium/Phosphorus ratio) and FTIR, measuring the mineral content of the hydroxyapatite crystal (Carbonate B/Phosphate) In Group R, baseline readings were recorded, all samples were demineralized for 96 hours. Readings were recorded after demineralization. The samples then entered a 7-day pH cycle, using the tested toothpastes in their corresponding groups during the pH cycle and the control group entered the pH cycle with no toothpaste used (acid challenged only). Final readings were recorded and the change in mineral content and microhardness measurements were assessed and statistically analyzed. In Group P, baseline readings were recorded, samples were not demineralized. The samples entered a 7-day pH cycle, using the tested toothpastes in their corresponding groups during the pH cycle and the control group entered the pH cycle with no toothpaste used (acid challenged only). Final readings were recorded and the change in mineral content and microhardness measurements were assessed and statistically analyzed. The results of this study revealed that in Group R, The highest mean value of Ca/P ratio change was found in (Zn/Co3 NHA) followed by (ACP SnF) the lowest mean value of Ca/P ratio change was found in (Control).