Comparative Evaluation of the Increase in Enamel Hardness Post-External Bleaching after Using Casein Phosphopeptide Amorphous Calcium Phosphate Fluoride (CPP-ACPF) and 5% Sodium Fluoride (NaF) Remineralizing Agents

The effects of the use of whitening mouthwash after home bleaching on the color stability and surface hardness of enamel

BACKGROUND

To evaluate the effectiveness of whitening mouthwashes, both with and without hydrogen peroxide (HP), after at-home teeth whitening in preserving the achieved whiteness and assessing their impact on enamel surface hardness.

METHODS

One hundred extracted human premolar teeth were divided into two groups, and home bleaching agents (Philips Zoom NiteWhite 22% Carbamide Peroxide, Ultradent Opalescence PF 16% Carbamide Peroxide) were applied to the groups. The teeth subjected to home bleaching were further divided into five subgroups, and each subgroup underwent a four-week cycle of application of a coloring agent and whitening mouthwash (Colgate Optic White (COW)(%2 HP), Rocs Black Edition (Rocs) (%1 HP), SPLAT Professional Bioactive gargle white Plus (SPLAT) (Ananas sativus fruit extract containing), Listerine Advanced White (Listerine) (Pyrophsphate containing), and distilled water (DW) (control)). Color and microhardness measurements were recorded at baseline, after home bleaching, and after treatment with whitening mouthwashes.

RESULTS

Compared with those treated with Opalescence PF, the samples treated with Zoom achieved a significantly greater degree of whitening (p < 0.001). When the effects of postwhitening mouthwash were evaluated (ΔE002), Listerine presented the lowest ΔE002 value in both home bleaching groups, whereas the control group presented the highest ΔE002 value. Both home-bleaching agents caused a significant increase in the initial WID values (p < 0.05). After home-bleaching, the increased WID values (WID2) significantly decreased in all mouthwash groups following exposure to the staining and whitening mouthwash cycle (WID3) (p < 0.05). The impact of home bleaching agents on microhardness was not significantly different (p = 0.151). When we examined the impact of whitening mouthwashes on microhardness, in the Zoom group, no statistically significant difference was observed in surface hardness (p > 0.05). However, in the Opalescence PF group, only the Listerine group showed a statistically significant increase (p < 0.05).

CONCLUSIONS

Higher concentrations of carbamide peroxide provide faster and more effective whitening. Whitening mouthwash containing HP and pyrophosphate is effective in maintaining tooth whiteness after home bleaching; however, its impact on enamel microhardness depends on the formulation. Notably, only Listerine in the Opalescence PF group significantly increased surface hardness. Given the drawbacks of HP, pyrophosphate-based mouthwash may serve as a safer alternative.

Efficacy of Sodium Fluoride and Fluoridated Calcium Phosphate in Mitigating Dental Erosion on Human Enamel: An In Vitro Analysis

INTRODUCTION

With increasing prevalence of dental erosion, this study explores the protective role of traditional fluoride-based products and newer formulations on eroded enamel.

AIMS

To assess the protective effectiveness of casein phosphopeptide-amorphous calcium phosphate fluoride (CPP-ACPF) and sodium fluoride (NaF) on human enamel against erosion using surface microhardness (SMH) and Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) analyses.

MATERIALS AND METHODS

Ten extracted human third molars were sectioned to obtain 40 enamel sections and randomly assigned into four groups (n = 10) and treated as follows: G1 (Sound Enamel), G2 (Erosive Challenge), G3 (CPP-ACPF + Erosive Challenge), and G4 (NaF + Erosive Challenge). All samples were subjected to Vicker's SMH analysis, while changes in surface morphology and elemental composition were validated in few representative samples using FTIR and SEM, respectively.

STATISTICAL ANALYSIS

Paired samples test, Kruskal-Wallis test, and Tukey HSD test were performed using SPSS software version 23 setting P value < 0.05 as statistically significant.

RESULTS

The mean SMH1 values for the experimental groups G3 and G4 were significantly higher (426.58VHN and 455.83VHN) when compared to G1 (P = 0.000) and G2 (P = 0.000). In SEM analysis, G2 showed eroded honeycomb appearance compared to the smooth homogenous surface of G1, while both G3 and G4 showed deposition of some precipitates. FTIR analysis revealed that in G3 and G4, a characteristic peak of phosphate vibrations between 528 and 823 cm-1 and carbonate bands at 845-932 cm-1 was observed.

CONCLUSIONS

Both CPP-ACPF and NaF demonstrated a protective effect on enamel against erosive challenge by an orange juice-based beverage.

The Efficacy of Silver Diamine Fluoride as a Caries Preventive Agent on Permanent Teeth: A Scoping Review

Dental caries is a chronic condition that affects people of all ages and has a high prevalence in Indonesia. Applying silver diamine fluoride (SDF) as a topical fluoridation agent is one of the approaches to prevent bacterial interactions that lead to the development of carious lesions. This study aims to determine the efficacy of SDF as a caries preventive agent on permanent teeth. Article searches were conducted using the keywords "silver diamine fluoride" AND "permanent tooth OR permanent teeth" AND "caries OR dental caries" AND "remineralize" through digital databases including PubMed, Cochrane Library, Science Direct, and Google Scholar. Articles with randomized controlled trial or nonrandomized controlled trial designs, articles written in Indonesian or English, publications published within the last 5 years (2016-2021), and aligned with the PCC (population, concept, and context) framework were included. Articles that were not accessible in full text or in a paid format, those that were of the meta-analysis or systematic review study type, and those that did not evaluate the use of SDF as a caries preventive agent were excluded from consideration. This scoping review refers to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extensions for Scoping Reviews (PRISMA-ScR) guidelines. A total of 8 articles were reviewed, encompassing various locations, designs, and samples, which demonstrated the use of SDF resulted in a high percentage of fluoride release with a high degree of remineralization efficacy. The deposition of crystals or minerals into fissures and crevices caused by demineralization indicated a reduction in lesion depth and influenced the microhardness of enamel. SDF can stimulate the rehardening of tooth structures rich in calcium and phosphate. The solution of SDF has the potential to serve as an alternative substance for preventing caries in permanent teeth because it enhances mineral precipitation and mineral density, promotes the remineralization of hydroxyapatite in enamel by increasing fluoride, and increases tooth structure resistance to acid attack.

Do Different Tooth Bleaching-Remineralizing Regimens Affect the Bleaching Effectiveness and Enamel Microhardness In Vitro?

Objective

Tooth bleaching may negatively affect the enamel surface properties, such as reduction in hardness values, and remineralizing agents can reverse these effects. This study evaluated the effect of remineralizing agents before, during, and after the bleaching process on enamel's whitening effectiveness and microhardness.

Methods and Materials

The initial color of 104 bovine incisors after immersion in tea solution was recorded, and then, the teeth were randomly divided into eight groups (n = 13). Group 1 (NC) was considered the control with no treatment, and Group 2 (B) was bleached with 40% hydrogen peroxide gel. The 3% fluorohydroxyapatite (FHA) and 2% sodium fluoride (NaF) were applied before (FHA/B, NaF/B), during (FHA + B, NaF + B) and after (B/FHA, B/NaF) the bleaching process in other groups. The final color and microhardness in three depths of 20-30, 50-60, and 100-120 µm were measured. Data were analyzed using Shapiro-Wilk, one-way ANOVA, Tukey, Games Howell, repeated measurement, and LSD tests.

Results

The FHA + B presented the lowest ΔE, significantly lower than other groups, except B/FHA. The ΔE in B/FHA was significantly lower than B/NaF. The bleaching significantly reduced the enamel hardness in three depths. The highest microhardness values were reported for B/NaF and NaF + B, which have no noticeable difference with NC, while FHA/B showed the lowest hardness in three depths, which was significantly lower than NC.

Conclusion

The application of NaF before, during, and after the bleaching improved the microhardness of bleached enamel as the unbleached one with no adverse effect on whitening effectiveness.