Evaluation of Different Dentifrice Compositions for Increasing the Hardness of Demineralized Enamel: An in Vitro Study

Abstract

This study aimed to evaluate microhardness of a dentifrice containing fluoride and arginine compared to a positive control (fluoride only) and a negative control (no fluoride) on sound and demineralized bovine enamel surfaces. Specimens were randomly assigned to different treatments that included daily pH cycling and brushing three times a day with one of the following dentifrices (n = 8): Neutraçucar (arginine and fluoride), Colgate Total 12 (fluoride) and My First Colgate (no fluoride). Enamel carious lesions were artificially created one week before the beginning of these treatments (demineralized bovine enamel (DE) groups). The same groups were also tested in sound enamel (sound bovine enamel (SE) groups). Microhardness was measured at baseline and after one, two, and five weeks of treatment using a Knoop indenter. Statistical analysis involved two-way Analysis of Variance (ANOVA) and Tukey’s test. After five weeks, both Total 12 and Neutraçucar had increased the microhardness of DE specimens (p < 0.05). Only Neutraçucar had increased the microhardness of the sound enamel after five weeks of treatment. Thus, it could be concluded that arginine-based dentifrices increase the microhardness of sound and demineralized bovine enamel surfaces.

Does the composition of toothpaste affect the tooth resistance to erosion/abrasion processes?

“…Besides that, the fluoride present in this dentifrice promoted the formation of calcium fluoride deposits on the enamel surface (Crastechini et al, 2019;Featherstone et al, 1982). Oliveira et al (2019) study showed that arginine-based dentifrices increase the microhardness of sound and demineralized bovine enamel surfaces and reported that the mechanism involved was the presence of free calcium ions in the oral environment make the saliva super-saturated and favor remineralization, despite the negative charge in demineralized hydroxyapatite crystals.…”

“…However, caution has to be taken when extrapolating these results to clinical conditions. Arginine based dentifrices were also introduced as a possibility to protect teeth against erosion and caries (Aguiar et al, 2017;Oliveira et al, 2019;West et al, 2017). Despite the positive results obtained with arginine addition, stannous fluoride (SnF2) based dentifrices showed superiority for protecting human teeth against the initiation and progression of dental erosion (West et al, 2017).…”

“…However, the results are representative since these limitations could be minimized. The bovine teeth have been largely adopted as a substrate for in vitro dental erosion experiments due to its advantages like the facility to obtain in large amounts, among others properties (Ionta et al, 2019;Oliveira et al, 2019;Soares et al, 2018;Soares et al, 2019). The levels of Ca and P ions that remain on the surface after treatment and erosion can be determined indirectly by µ-EDXRF (Soares et al, 2018;Soares et al, 2019).…”

“…Current commercially available dentifrices based on formulae containing 8% arginine and calcium carbonate combined with sodium monofluorophosphate (MFP) were tested in dentin (Olley et al, 2012;Poggio et al, 2017; and enamel erosion (Lombardini et al, 2014;Oliveira et al, 2019;West et al, 2017) and they offer some degree of protection or remineralization. Oliveira et al (2019) compared a dentifrice containing 1.5% arginine, 1450 ppm of fluoride, and sodium MFP in insoluble calcium to a conventional dentifrice containing 1450 ppm of fluoride and a dentifrice without fluoride. The authors concluded that arginine-based dentifrices increase the microhardness of sound and enamel carious lesions.…”

“ Evaluation of the Effect of Two Different Concentration of Arginine on Fluoride Uptake by Demineralized Enamel Surfaces” in vitro study

“…et al, (30) and Oliveira. et al, (36) in which results showed that fluoride and arginine could increase the microhardness of sound and demineralized bovine enamel surfaces. It is possible that arginine-fluoride complexes could have been stored within enamel, 205…”