Use of Reflectometer Optipen to assess the preventive effect of a sugarcane cystatin on initial dental erosion in vivo

Impact of modifications on the characteristics of salivary pellicle on dental hard tissue: a scoping review

OBJECTIVES

The salivary pellicle regulates interfacial events on dental surfaces and is a promising target for modification to improve dental health. This scoping review systematically examines substances that modify the pellicle, evaluating their potential and identifying knowledge gaps.

DATA

This review followed the PRISMA-ScR guidelines. Studies investigating how substances applied during pellicle formation on enamel or dentin affect its structure, composition, or protective function were included.

SOURCES

A systematic search of Medline was conducted up to March 2024 using predefined terms. Only English-language research articles were included. No hand-searching was performed.

STUDY SELECTION

A total of 864 records were identified. After title and abstract screening, 110 articles were assessed in full, resulting in 85 eligible studies for data charting. These studies investigated human saliva-derived pellicles on enamel or dentin, comparing their composition, structure, or protective properties with and without modification. Most studies, conducted equally in vitro and in situ, focused on fluorides and metals (n = 28), peptides and proteins (n = 21), and polyphenols (n = 18), while other substances were less frequently examined (n = 17). Modifications affected the pellicle's ultrastructure, altered its proteome, or enhanced its protective role against erosion, abrasion, and bacterial adherence.

CONCLUSIONS

Despite numerous studies and distinct substance classes, findings remain inconclusive and must be interpreted within the context of individual study designs.

CLINICAL SIGNIFICANCE

Modifying the pellicle can improve its protective function, presenting a promising approach for preventive dentistry. However, the long-term effects of these substances within the dynamic oral environment remain unclear. This review underscores the need for further research to close existing knowledge gaps and confirm clinical relevance.

In vitro reduction of enamel erosion by sugarcane-derived cystatin associated with sodium trimetaphosphate

The objective of this in vitro study was to assess the efficacy of CaneCPI-5, either alone or in combination with various concentrations of sodium trimetaphosphate (TMP) in protecting against initial enamel erosion. A total of 135 bovine enamel specimens were prepared and categorized into nine groups (n/group=15) according to the following treatments: Deionized water; Commercial solution (Elmex Erosion ProtectionTM); 0.1 mg/mL CaneCPI-5; 0.5% TMP; 1.0% TMP; 3.0% TMP; 0.1 mg/mL CaneCPI-5+0.5% TMP; 0.1 mg/mL CaneCPI-5+1.0%TMP; and 0.1 mg/mL CaneCPI-5+3.0%TMP. The specimens were treated with the respective solutions for 2 h, followed by acquired enamel pellicle formation for 2 h and exposure to 0.65% citric acid (CA) for 1 min. These procedures were repeated once a day for three consecutive days. Demineralization was assessed by the percentage change in surface hardness (%CSH) and calcium release into CA, analyzed by the Arsenazo III method. The data were evaluated using Kruskal-Wallis/Dunn's tests. Regarding %CSH, CaneCPI-5+3.0%TMP was the most effective treatment when compared to the CaneCPI-5 group alone. As for calcium release into CA, the CaneCPI-5+0.5% TMP and CaneCPI-5 groups (both with lower calcium release) did not significantly differ from the commercial solution. In conclusion, combination of CaneCPI-5 with TMP enhances the protective potential against initial enamel erosion in vitro.

Designing mouthwash formulations with innovative molecular components to control initial dental erosion in vivo

OBJECTIVE

This study aimed to examine and compare the efficacy of mouthwashes containing different proteins and peptide on the prevention of enamel erosion in vivo, as well as to evaluate the participants' satisfaction with the formulations.

METHODS

Twelve participants were selected and underwent five cross-over mouthwash phases: Water (control); 0.1 mg/mL CaneCPI-5; 0.5 mg/mL MaquiCPI-3; 0.1 mg/mL CsinCPI-2; and 0.037 mg/mL Stn15pSpS. After prophylaxis, the participants rinsed (1 min), followed by the acquired enamel pellicle (AEP) formation (2 h). An erosive challenge was made (biopsy, citric acid 1%, 15s) on the buccal surface of the central maxillary incisors. The Relative Surface Reflection Intensity (%SRI) was assessed and analyzed by ANOVA/Tukey's tests. The calcium release in acid was measured by the Arsenazo method and verified by Kruskal-Wallis/Dunn's tests. The Spearman's correlation was used between analyses. A questionnaire evaluated the satisfaction of participants.

RESULTS

For both analyses, the results showed that mouthwashes containing the proteins or peptide were significantly more effective in preventing enamel erosion compared to deionized water, with no significant differences among the active ingredients (p < 0.05). Also, there was a significant negative correlation between %SRI and calcium released (r=-0.5754). The questionnaire revealed that the volunteers were satisfied with the taste of the products. In addition, the experimental procedures were well tolerable, and no side effects were reported.

CONCLUSION

All mouthwashes containing proteins or peptide were acceptable and effective in protecting enamel against initial dental erosion in vivo.

CLINICAL SIGNIFICANCE

This study highlights the potential of these pioneer organic components for the development of mouthwashes designed for people with risk of erosive tooth wear.

Acquired enamel pellicle and biofilm engineering with a combination of acid-resistant proteins (CaneCPI-5, StN15, and Hemoglobin) for enhanced protection against dental caries - in vivo and in vitro investigations

OBJECTIVE

This study was designed in two-legs. In the in vivo, we explored the potential of a rinse solution containing a combination (Comb) of 0.1 mg/mL CaneCPI-5 (sugarcane-derive cystatin), 1.88 × 10- 5M StN15 (statherin-derived peptide) and 1.0 mg/mL hemoglobin (Hb) to change the protein profile of the acquired enamel pellicle(AEP) and the microbiome of the enamel biofilm. The in vitro, was designed to reveal the effects of Comb on the viability and bacterial composition of the microcosm biofilm, as well as on enamel demineralization.

MATERIALS AND METHODS

In vivo study, 10 participants rinsed (10mL,1 min) with either deionized water (H2O-control) or Comb. AEP and biofilm were collected after 2 and 3 h, respectively, after rinsing. AEP samples underwent proteomics analysis, while biofilm microbiome was assessed via 16 S-rRNA Next Generation Sequencing(NGS). In vitro study, a microcosm biofilm protocol was employed. Ninety-six enamel specimens were treated with: 1)Phosphate-Buffered Solution-PBS(negative-control), 2)0.12%Chlorhexidine, 3)500ppmNaF and 4)Comb. Resazurin, colony-forming-units(CFU) and Transversal Microradiography(TMR) were performed.

RESULTS

The proteomic results revealed higher quantity of proteins in the Comb compared to control associated with immune system response and oral microbial adhesion. Microbiome showed a significant increase in bacteria linked to a healthy microbiota, in the Comb group. In the in vitro study, Comb group was only efficient in reducing mineral-loss and lesion-depth compared to the PBS.

CONCLUSIONS

The AEP modification altered the subsequent layers, affecting the initial process of bacterial adhesion of pathogenic and commensal bacteria, as well as enamel demineralization.

CLINICAL RELEVANCE

Comb group shows promise in shaping oral health by potentially introducing innovative approaches to prevent enamel demineralization and deter tooth decay.

Acquired Pellicle and Biofilm Engineering by Rinsing with Hemoglobin Solution

INTRODUCTION

The identification of acid-resistant proteins, including hemoglobin (Hb), within the acquired enamel pellicle (AEP) led to the proposition of the "acquired pellicle engineering" concept, which involves the modification of the AEP by incorporating specific proteins, presenting a novel strategy to prevent dental demineralization.

OBJECTIVE

Combining in vivo and in vitro proof-of-concept protocols, we sought to reveal the impact of AEP engineering with Hb protein on the biofilm microbiome and enamel demineralization.

METHODS

In the in vivo studies, 10 volunteers, in 2 independent experiments, rinsed (10 mL,1 min) with deionized water-negative control or 1.0 mg/mL Hb. The AEP and biofilm formed along 2 or 3 h, respectively, were collected. AEP was analyzed by quantitative shotgun-label-free proteomics and biofilm by 16S-rRNA next-generation sequencing (NGS). In in vitro study, a microcosm biofilm protocol was employed. Seventy-two bovine enamel specimens were treated with (1) phosphate-buffered solution (PBS), (2) 0.12% chlorhexidine, (3) 500 ppm NaF, (4) 1.0 mg/mL Hb, (5) 2.0 mg/mL Hb, and (6) 4.0 mg/mL Hb. The biofilm was cultivated for 5 days. Resazurin, colony forming units (CFU), and transversal microradiography were performed.

RESULTS

Proteomics and NGS analysis revealed that Hb increased proteins with antioxidant, antimicrobial, acid-resistance, hydroxyapatite-affinity, calcium-binding properties and showed a reduction in oral pathogenic bacteria. In vitro experiments demonstrated that the lowest Hb concentration was the most effective in reducing bacterial activity, CFU, and enamel demineralization compared to PBS.

CONCLUSION

These findings suggest that Hb could be incorporated into anticaries dental products to modify the oral microbiome and control caries, highlighting its potential for AEP and biofilm microbiome engineering.

A new role for resveratrol: Protection of enamel against erosion

OBJECTIVE

The aim of this study was to determine the effect of different concentrations of resveratrol in protecting enamel against initial dental erosion in vitro.

METHODS

Ninety bovine enamel samples (4 × 4 mm) were divided into six groups: Phosphate buffered saline (negative control; PBS), Commercial solution (Elmex Erosion Protection™; positive control) and resveratrol at 4 different concentrations (1, 10, 100 or 400 µg/mL). Initially, the samples were incubated in saliva for the formation of the acquired pellicle (250 µL, 1 h, 37 °C, 250 rpm). Afterward, the samples were incubated in the respective treatments (250 µL, 1 min, 37 °C, 250 rpm) and then reincubated in saliva (250 µL, 1 h, 37 °C, 250 rpm). Finally, the samples were subjected to an erosive challenge by incubating in 1 % citric acid (1 mL, pH 3.5, 1 min, 25 °C, 250 rpm). The percentage surface microhardness change (% SMC) was assessed using a microhardness tester. Data were analyzed by Kruskal-Wallis and Dunn's tests (p < 0.05).

RESULTS

The treatments with Elmex™ and resveratrol (1, 10 and 100 µg/mL) significantly protected enamel compared to the negative control, without significant differences among them. However, the group treated with the highest resveratrol concentration (400 µg/mL) did not show a significant difference from the negative control.

CONCLUSIONS

Resveratrol at concentrations ranging from 1 to 100 µg/ml was effective in preventing loss of enamel surface microhardness.

CLINICAL SIGNIFICANCE

This result suggests a potential new direction for the development of dental products based on resveratrol for the prevention of dental erosion.

Hemoglobin Protects Enamel against Intrinsic Enamel Erosive Demineralization

INTRODUCTION

This study investigated the changes in the acquired enamel pellicle (AEP) proteome when this integument is formed in vivo after treatment with sugarcane-derived cystatin (CaneCPI-5), hemoglobin (HB), and a statherin-derived peptide (StN15), or their combination and then exposed to an intrinsic acid challenge. The effectiveness of these treatments in preventing intrinsic erosion was also evaluated.

METHODS

Ten volunteers, after prophylaxis, in 5 crossover phases, rinsed with the following solutions (10 mL, 1 min): control (deionized water-H2O) - group 1, 0.1 mg/mL CaneCPI-5 - group 2, 1.0 mg/mL HB - group 3, 1.88 × 10-5M StN15 - group 4, or a blend of these - group 5. Following this, AEP formation occurred (2 h) and an enamel biopsy (10 µL, 0.01 m HCl, pH 2.0, 10 s) was conducted on one incisor. The biopsy acid was then analyzed for calcium (Arsenazo method). The vestibular surfaces of the other teeth were treated with the same acid. Acid-resistant proteins in the residual AEP were then collected and analyzed quantitatively via proteomics.

RESULTS

Compared to control, treatment with the proteins/peptide, mixed or isolated, markedly enhanced acid-resistant proteins in the AEP. Notable increases occurred in pyruvate kinase PKM (11-fold, CaneCPI-5), immunoglobulins and submaxillary gland androgen-regulated protein 3B (4-fold, StN15), Hb, and lysozyme C (2-fold, StN15). Additionally, a range of proteins not commonly identified in the AEP but known to bind calcium or other proteins were identified in groups treated with the tested proteins/peptide either in isolation or as a mixture. The mean (SD, mM) calcium concentrations released from enamel were 3.67 ± 1.48a, 3.11 ± 0.72a, 1.94 ± 0.57b, 2.37 ± 0.90a, and 2.38 ± 0.45a for groups 1-5, respectively (RM-ANOVA/Tukey, p < 0.05).

CONCLUSIONS

Our findings demonstrate that all treatments, whether using a combination of proteins/peptides or in isolation, enhanced acid-resistant proteins in the AEP. However, only HB showed effectiveness in protecting against intrinsic erosive demineralization. These results pave the way for innovative preventive methods against intrinsic erosion, using "acquired pellicle engineering" techniques.

Effect of an experimental TiF4/NaF solution in preventing tooth erosion

OBJECTIVE

This was a randomized, double-blind, parallel, placebo-controlled in vivo study investigating the protective potential of a titanium tetrafluoride/ sodium fluoride (TiF4/NaF) solution compared to its respective positive and negative controls under an in vivo model, as well as the perception of participants regarding the use of this experimental solution.

METHODS

After the ethics approval and the selection procedures, 33 participants were divided into three treatments: TiF4/NaF solution (500 ppm F, pH 4.4); AmF/NaF/SnCl2-mouthwash (500 ppm F, pH 4.5) and water (pH 7.0) (n = 11). After professional cleaning, the participants rinsed with one of the solutions for one minute and waited two hours for the erosive challenge. The erosive solution (1 % citric acid, pH 2.5) was applied for 10 s on each central incisor (enamel area: 4 mm2) and collected for calcium analysis using III Arsenazo colorimetric method. The Ca2+ release data were compared using Kruskal-Wallis/ Dunn tests (p < 0.05).

RESULTS

Teeth treated with both fluoride solutions released less calcium into the acid (median and interquartile interval: TiF4/NaF - 0.45/0.19 mM and AmF/NaF/SnCl2 - 0.46/0.15 mM Ca2+, p = 0.99) compared to the negative control (1.12/0.42 mM Ca2+, 60 % reduction, p < 0.0006). For both F solutions, only one participant per group reported unpleasant taste. Four participants belonging to AmF/NaF/SnCl2-mouthwash reported burning sensation post-rinse, while only one participant described such feeling after TiF4/NaF rinsing.

CONCLUSION

The experimental TiF4/NaF solution was as effective as the commercial AmF/NaF/SnCl2-mouthwash in protecting enamel against erosive demineralization with a good acceptability by the participants.

Acquired pellicle engineering with the association of cystatin and vitamin E against enamel erosion

OBJECTIVE

Evaluate CaneCPI-5 associated with Vitamin E in acquired enamel pellicle (AEP) engineering to prevent dental erosion.

METHODS

180 human enamel specimens were divided into 12 groups and treated with the following solutions: Cane+VitT and Cane+VitS- CaneCPI-5 + Vit E; Vit+CaneT and Vit+CaneS- Vit E + CaneCPI-5; VitT and VitS- Vit E; CaneT and CaneS- CaneCPI-5; ControlT and ControlS - AmF/NaF/SnCl2; WaterT and WaterS- Deionized water. Groups' name followed by "T" were first treated (200 μl; 2 min) and then incubated in human saliva (200 μl; 1 h) to form the AEP. For groups followed by "S", the AEP was formed and then treatment was applied. The erosive challenge consisted of immersion in 1% citric acid (1 min, 1x/day, for 3 days). The percentage of superficial hardness loss (%SHL) and the relative surface reflection intensity (%SRI) were subjected to normality and homogeneity tests, Shapiro-Wilk and Levene tests, respectively. Subsequently, the data were analyzed using two-way ANOVA, Tukey's test and Pearson's correlation (p < 0.005).

RESULTS

For%SHL and%SRI, water controls showed significantly lower protective capacity. Cane+VitT, Cane+VitS, and Vit+CaneS presented the lowest%SHL, and VitT and VitS did not differ from Vit+CaneT, but they were different from the other groups (p = 0.002). The greatest%SRI was found for the Cane+VitT, Vit+CaneT, VitT, Cane+VitS, Vit+CaneS, and VitS groups, which did not significantly differ. CaneT and ControlT, showed similar reflections compared to CaneS and ControlS.

CONCLUSION

CaneCPI-5 and Vitamin E demonstrated a synergistic protective effect against initial erosion.

CLINICAL SIGNIFICANCE

The results open up new possibilities for preventive approaches against erosion through the acquired pellicle engineering, with the combination of CaneCPI-5 and Vitamin E, which demonstrated to be more effective than commercial stannous mouthwash. Further research is warranted to explore the potential of this combination in diverse clinical settings.

Different vehicles containing CaneCPI-5 reduce erosive dentin wear in situ

OBJECTIVE

This study evaluated the protective capacity of a sugarcane-derived cystatin (CaneCPI-5) in different vehicles (1-solution and 2-chitosan gel) against erosive dentin wear in situ.

METHODS

In part-1, 15 volunteers participated in a crossover protocol (solutions): Water; Elmex™ and CaneCPI-5. The volunteers wore an appliance with 4 dentin samples for 5 days. These samples were treated with a drop of the solutions for 1 min (4X/d), then the acquired pellicle (AP) was formed and the samples were subjected to erosive challenges (EROSION: citric acid, for 90 s, 4X/day). 2X/day, half of the samples were also abraded for 15 s (ABRASION). In part-2, 16 volunteers participated in a crossover protocol (gel): No gel, Chitosan gel, Chitosan gel + NaF and Chitosan gel + CaneCPI-5. The volunteers also wore an appliance. The samples were treated once/day with the gel or not for 4 min, then the AP was formed and the samples were subjected to erosive and abrasive challenges, as reported in part-1. Dentin wear was measured by profilometry. Data were analyzed by two-way RM-ANOVA and Sidak's tests (p < 0.05).

RESULTS

Part-1: Elmex™ and CaneCPI-5 significantly reduced dentin loss in comparison with Water for the EROSION/ABRASION conditions (p < 0.05). Part-2, all the treated groups significantly reduced the dentin loss in comparison to the No gel. The greatest reduction was found for the gel + CaneCPI-5 group for the EROSION/ABRASION (p < 0.05).

CONCLUSION

The solution and chitosan gel containing CaneCPI-5 protected against erosive dentin wear in situ.

CLINICAL RELEVANCE

These different vehicles are probably sufficient for protecting people with high risk of developing erosive dentin wear.

Maquiberry Cystatins: Recombinant Expression, Characterization, and Use to Protect Tooth Dentin and Enamel

Phytocystatins are proteinaceous competitive inhibitors of cysteine peptidases involved in physiological and defensive roles in plants. Their application as potential therapeutics for human disorders has been suggested, and the hunt for novel cystatin variants in different plants, such as maqui (Aristotelia chilensis), is pertinent. Being an understudied species, the biotechnological potential of maqui proteins is little understood. In the present study, we constructed a transcriptome of maqui plantlets using next-generation sequencing, in which we found six cystatin sequences. Five of them were cloned and recombinantly expressed. Inhibition assays were performed against papain and human cathepsins B and L. Maquicystatins can inhibit the proteases in nanomolar order, except MaquiCPIs 4 and 5, which inhibit cathepsin B in micromolar order. This suggests maquicystatins' potential use for treating human diseases. In addition, since we previously demonstrated the efficacy of a sugarcane-derived cystatin to protect dental enamel, we tested the ability of MaquiCPI-3 to protect both dentin and enamel. Both were protected by this protein (by One-way ANOVA and Tukey's Multiple Comparisons Test, p < 0.05), suggesting its potential usage in dental products.