Film-Forming Polymers for Inhibition of Hydroxyapatite Dissolution: A Screening Study.

The aim of this study was to evaluate the effect of film-forming polymer solutions of different concentrations and pH values, either associated or not with sodium fluoride (F; 225 ppm F-), when applied during the initial stage of salivary pellicle formation, to prevent the dissolution of hydroxyapatite (HA), which was determined by the pH-stat method. Polyacrylic acid (PA), chitosan, sodium linear polyphosphate (LPP), polyvinyl methyl ether/maleic anhydride (PVM/MA), and propylene glycol alginate (PGA) were tested in three concentrations (lower, medium, and higher), two pH values (native or adjusted), and either associated or not with F. Distilled water, F, and stannous ion+fluoride (Sn/F; 225 ppm F- and 800 ppm Sn2+, as SnCl2) solutions were the controls, totalizing 63 groups. HA crystals were pretreated with human saliva for 1 min to allow pellicle formation, then immersed in the experimental solutions (1 min), and exposed to saliva for another 28 min. Subsequently, they were added to a 0.3% citric acid solution (pH = 3.8), connected to a pH-stat system that added aliquots of 28 µL 0.1 N HCl for a total reaction time of 5 min. Data were analyzed with one-way ANOVA and Tukey's tests (α = 0.05). For PA alone, the concentrations of 0.1% (native pH), 0.06%, and 0.08% (both pH adjusted) showed significantly lower HA dissolution than the negative control. PA concentrations of 0.1% and 0.08%, of both pH values, improved the effect of F against HA dissolution to a near-identical value as Sn/F. All solutions containing chitosan and LPP significantly reduced HA dissolution in comparison with the control. For chitosan, the concentration of 0.5% (in both pH values) improved the effect of F. LPP at 0.5% (native pH) and all associations of LPP with F outperformed the effect of F. Some PVM/MA solutions significantly reduced HA dissolution but PVM/MA could not improve the protection of F. PGA was incapable of reducing HA dissolution or improving F effect. It was concluded that chitosan, LPP, and some PA and PVM/MA solutions used alone were capable of reducing HA dissolution. Only PA, chitosan, and LPP were able to enhance fluoride protection, but for PA and chitosan, this was influenced by the polymer concentration.

Proteomic analysis of stimulated saliva in gastroesophageal reflux disease patients with and without erosive tooth wear: Observational study.

OBJECTIVE: To evaluate the difference in the proteomic profile of stimulated saliva in patients with gastroesophageal reflux disease (GERD) with (GE) and without (GNE) erosive tooth wear (ETW), regarding both human and bacterial proteins. METHODS: Stimulated saliva (SS) was collected from 16 patients (8/group). Samples were centrifuged at 4.500 g for 15 min under refrigeration to remove all debris. The supernatant from each saliva sample was taken and frozen at -80 °C. After extracting the proteins, they were submitted to reverse phase liquid chromatography and mass spectrometry (nLC-ESI-MS/MS). Label-free proteomic quantification was performed using Protein Lynx Global Service (PLGS) software (p < 0.05) for human and bacterial proteins. RESULTS: In total, 67 human proteins were common for GNE and GE groups. GNE group presented, compared to GE group, increase in proteins that confer antimicrobial and acid resistant properties, such as cystatins, histatin and immunoglobulins. However, GNE group had a marked decrease in subunits of hemoglobin (α, ß and delta). Regarding bacterial proteins, for SS, 7 and 10 unique proteins were identified in the GE and GNE groups, respectively. They are related to protein synthesis and energy metabolism and interact with human proteins typically found in saliva and supramolecular complexes of the acquired pellicle. CONCLUSIONS: Our data indicate that the stimulation of the salivary flow increases acid resistant and antimicrobial proteins in saliva, which might protect against ETW. CLINICAL SIGNIFICANCE: This pioneer study showed important differences in the human and bacterial proteome of SS in patients with GERD with or without ETW.

Rinsing solutions containing natural extracts and fluoride prevent enamel erosion in vitro.

BACKGROUND: Polyphenols interact with salivary proteins and thus can improve the pellicle's erosion protective properties. This effect could be exploited to create rinsing solutions with polyphenols as active ingredients for erosion prevention. Different from the current gold standard for erosion protective rinsing solutions, these rinses would not rely on stannous ions. This would offer alternatives for patients with concerns regarding the composition of rinsing solutions and preferring bio-products. OBJECTIVE: To develop an erosion-preventive rinsing solution containing natural polyphenol-rich extracts. METHODOLOGY: Solutions were prepared with polyphenols from either grapeseed extract or cranberry extract, 500 ppm fluoride added, and additionally flavors and sweeteners. Controls were deionized water, 500 ppm fluoride solution, and the gold standard rinse in the field (Sn2+/F-). In total, 135 enamel specimens (n=15/group) were subjected to five cycles of salivary pellicle formation (30 min, 37°C), modification with the solutions (2 min, 25°C), further salivary pellicle formation (60 min, 37°C), and erosive challenge (1 min, 1% citric acid, pH 3.6). Relative surface microhardness (rSMH), surface reflection intensity (rSRI), and amount of calcium release (CaR) were investigated. Data were analyzed with Kruskal-Wallis and Wilcoxon rank sum tests (α=0.05). RESULTS: The polyphenol solutions containing fluoride, as well as additional flavors, protected enamel better than fluoride alone, and similar to the Sn2+/F- solution, when investigating both rSMH and CaR. When measuring rSRI, Sn2+/F- showed the best protection, while the polyphenol solutions were similar to fluoride. CONCLUSION: For two of the three assessed parameters (rSMH and CaR), both developed polyphenol-rich rinsing solutions were able to protect enamel from erosion, improving/potentializing the effect of fluoride and matching the protection offered by the current gold standard rinsing solution.

Plant extracts have dual mechanism on the protection against dentine erosion: action on the dentine substrate and modification of the salivary pellicle.

To investigate the effect of some polyphenol-rich plant extracts on the protection of dentine against demineralization, both acting on the dentine and on the salivary pellicle. Dentine specimens (n = 180) were randomly distributed into 6 experimental groups (n = 30/group): Control (deionized water), Açaí extract, Blueberry extract, Green tea extract, Grape seed extract, and Sn2+/F- (mouthrinse containing stannous and fluoride). Each group was further divided into two subgroups (n = 15), according to the site of action of the substance: on the dentine surface (D) or on the salivary pellicle (P). The specimens were submitted to 10 cycles: 30 min incubation in human saliva (P) or only in humid chamber (D), 2 min immersion in experimental substances, 60 min of incubation in saliva (P) or not (D), and 1 min erosive challenge. Dentine surface loss (DSL), amount of degraded collagen (dColl) and total calcium release were analyzed. Green tea, Grape seed and Sn2+/F- showed significant protection, with least DSL and dColl. The Sn2+/F- showed better protection on D than on P, whereas Green tea and Grape seed showed a dual mode of action, with good results on D, and even better on P. Sn2+/F- showed the lowest values of calcium release, not differing only from Grape seed. Sn2+/F- is more effective when acting directly on the dentine surface, while Green tea and Grape seed have a dual mode of action: with a positive effect on the dentine surface itself, but an improved efficacy in the presence of the salivary pellicle. We further elucidate the mechanism of action of different active ingredients on dentine erosion, where Sn2+/F- acts better on the dentine surface, but plant extracts have a dual mode of action, acting on the dentine itself as well as on the salivary pellicle, improving the protection against acid demineralization.

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

The sugarcane cystatin 5 (CaneCPI-5) showed protection against erosion and erosive tooth wear (ETW) under several protocols. However, evaluating these conditions in vivo is hard due to the lack of a suitable device. The aim of this study was to use clinically the relative surface reflection intensity (%SRI) by the Reflectometer Optipen to assess the acquired pellicle engineering with CaneCPI-5 rinse for the prevention of initial erosion in vivo. Nine volunteers were distributed in three cross-over phases, according to the rinse used, as follows: 1) Deionized water (negative control); 2) Elmex® (800 ppm Sn2+, 500 ppm F-; positive control); 3) 0.1 mg/mL CaneCPI-5. The following experimental steps were performed: Initially, the volunteers received prophylaxis and the initial %SRI was performed. Subsequently, they rinsed with the solutions (10 mL; 1min), followed by the formation of the acquired enamel pellicle (AEP; 120min). After, the erosive challenge with citric acid 1%, pH 2.5 (10 µL; 10s) was performed (in isolation) on the buccal surface of the maxillary central incisors (right and left). The calcium present in the acid was analyzed by Arsenazo III method. Finally, the final %SRI was performed. Data were analyzed by Kruskal-Wallis/Dunn's tests and Spearman's correlation were used (p < 0.05). For both variables, the negative control led to significantly less protection (lower reflectivity and higher calcium release) in comparison with the other groups. The best protection (higher reflectivity and lower calcium release) was observed for the Elmex® and the CaneCPI-5 groups, with no significant differences between them (p < 0.05). There was a significant correlation between both analyzes. The Reflectometer Optipen demonstrated to be a good device to assess clinically. Moreover, CaneCPI-5 rinse proved effective through acquired pellicle engineering against initial erosion in vivo.

New insights into the protective effect of statherin-derived peptide for different acquired enamel pellicle formation times on the native human enamel surfaces.

OBJECTIVES: This study evaluated the protective impact of acquired enamel pellicle (AEP) engineering with statherin-derived peptide (StatpSpS), considering different AEP formation times. DESIGN: A total of 120 native human enamel specimens were divided into 2 main groups: 1) No AEP engineering and 2) AEP engineering with StatpSpS (pretreatment for 1 min; 37 °C, under agitation). Each group was further divided into 4 subgroups: No pellicle, or 1, 60-and-120 min AEP formation times (human saliva; 37 °C). The specimens were then subjected to an erosive challenge (1% citric acid; pH 3.6; 1 min; 25 °C). This procedure was repeated for 5 cycles. Relative surface reflection intensity (%SRI) was measured and scanning electron microscopy (SEM) of the enamel surface was done. RESULTS: All AEP engineering groups protected against initial dental erosion in comparison with No pellicle (p < 0.001), likewise all groups with AEP, independent of engineering or formation times (p 0.001). Furthermore, engineering with StatpSpS even without the presence of AEP protected the enamel when compared to the No engineering/No pellicle group (p < 0.0001). No difference was observed regarding the protection from the different AEP formation times (p > 0.05). Regarding the SEM analysis, in the "No AEP engineering & No AEP" group, a more severe effect of citric acid was observed, with more enamel prism heads and scratches on the surface when compared with the other groups. CONCLUSIONS: AEP provides almost instant protection at formation times even as short as 1 min, protecting the native enamel against erosion. Treatment with StatpSpS by itself provides similar protection as the AEP.

Acquired enamel pellicle protects gastroesophageal reflux disease patients against erosive tooth wear

Abstract The objective of this study was to compare the protein profile of the acquired enamel pellicle (AEP) formed in vivo in patients with or without gastroesophageal reflux disease (GERD), and with or without erosive tooth wear (ETW). Twenty-four volunteers were divided into 3 groups: 1) GERD and ETW; 2) GERD without ETW; and 3) control (without GERD). The AEP formed 120 min after prophylaxis was collected from the lingual/palatal surfaces. The samples were subjected to mass spectrometry (nLC-ESI-MS/MS) and label-free quantification by Protein Lynx Global Service software. A total of 213 proteins were identified, or 119, 92 and 106 from each group, respectively. Group 2 showed a high number of phosphorylated and calcium-binding proteins. Twenty-three proteins were found in all the groups, including 14-3-3 protein zeta/delta and 1-phosphatidylinositol. Several intracellular proteins that join saliva after the exfoliation of oral mucosa cells might have the potential to bind hydroxyapatite, or participate in forming supramolecular aggregates that bind to precursor proteins in the AEP. Proteins might play a central role in protecting the dental surface against acid dissolution.

Rinsing solutions containing natural extracts and fluoride prevent enamel erosion in vitro

Abstract Polyphenols interact with salivary proteins and thus can improve the pellicle's erosion protective properties. This effect could be exploited to create rinsing solutions with polyphenols as active ingredients for erosion prevention. Different from the current gold standard for erosion protective rinsing solutions, these rinses would not rely on stannous ions. This would offer alternatives for patients with concerns regarding the composition of rinsing solutions and preferring bio-products. Objective To develop an erosion-preventive rinsing solution containing natural polyphenol-rich extracts. Methodology Solutions were prepared with polyphenols from either grapeseed extract or cranberry extract, 500 ppm fluoride added, and additionally flavors and sweeteners. Controls were deionized water, 500 ppm fluoride solution, and the gold standard rinse in the field (Sn2+/F-). In total, 135 enamel specimens (n=15/group) were subjected to five cycles of salivary pellicle formation (30 min, 37°C), modification with the solutions (2 min, 25°C), further salivary pellicle formation (60 min, 37°C), and erosive challenge (1 min, 1% citric acid, pH 3.6). Relative surface microhardness (rSMH), surface reflection intensity (rSRI), and amount of calcium release (CaR) were investigated. Data were analyzed with Kruskal-Wallis and Wilcoxon rank sum tests (α=0.05). Results The polyphenol solutions containing fluoride, as well as additional flavors, protected enamel better than fluoride alone, and similar to the Sn2+/F- solution, when investigating both rSMH and CaR. When measuring rSRI, Sn2+/F- showed the best protection, while the polyphenol solutions were similar to fluoride. Conclusion For two of the three assessed parameters (rSMH and CaR), both developed polyphenol-rich rinsing solutions were able to protect enamel from erosion, improving/potentializing the effect of fluoride and matching the protection offered by the current gold standard rinsing solution.

Synergistic effect between plant extracts and fluoride to protect against enamel erosion: An in vitro study.

Polyphenol-rich solutions, such as plant extracts and teas, can modify the salivary pellicle and improve the protection against dental erosion. In this study, we further explored how these polyphenol-rich plant extracts solutions behave in the presence of fluoride. We distributed enamel specimens into 9 groups (n = 15): Control_No_F- (Deionized water); Control_F- (500 ppm F-), Grape_Seed_No_F- (Grape seed extract), Grape_Seed_F- (Grape seed extract + 500 ppm F-), Grapefruit_Seed_No_F- (Grapefruit seed extract), Grapefruit_Seed_F- (Grapefruit seed extract + 500 ppm F-), Blueberry_No_F- (Blueberry extract), Blueberry_F- (Blueberry extract + 500 ppm F-), and Sn2+/F-_Rinse (commercial solution containing 800 ppm Sn2+ and 500 ppm F-). The specimens were submitted to 5 cycles (1 cycle per day), and each cycle consisted of: salivary pellicle formation (human saliva, 30 min, 37°C), modification of the pellicle (2 min, 25°C), pellicle formation (60 min, 37°C), and an erosive challenge (1 min, citric acid). Between cycles, the specimens were kept in a humid chamber. Relative surface hardness (rSH), relative surface reflection intensity (rSRI) and calcium released to the acid were analysed, using general linear models, and Kruskal-Wallis with post-hoc Dunn's tests. We observed that the presence of fluoride in synergy with the extract solutions provided better protection than the groups containing extract or fluoride only. For rSH, we observed a significant main effect of extracts (F(4,117) = 9.20; p<0.001) and fluoride (F(1,117) = 511.55; p<0.001), with a significant interaction (F(3,117) = 6.71; p<0.001). Grape_Seed_F- showed the best protection, better than fluoride, and Sn2+/F-_Rinse. Calcium results also showed greater protection for the groups containing fluoride, whereas for rSRI, despite a significant interaction between extract and fluoride (F(3,117) = 226.05; p<0.001), the differences between the groups were not as clearly observed. We conclude that polyphenols from plant extracts, when combined with fluoride, improve the protective effect of salivary pellicles against enamel erosion.

Preventive effect of chitosan gel containing CaneCPI-5 against enamel erosive wear in situ.

OBJECTIVE: This study evaluated the preventive effect of a chitosan gel containing CaneCPI-5 against enamel erosion and erosion + abrasion in situ. METHODS: Sixteen volunteers participated in a crossover, double-blind protocol, comprising 4 phases: (1) no treatment (Nt); (2) chitosan gel (Cg); (3) chitosan gel + 12,300 ppm NaF (Cg + NaF); and (4) chitosan gel + 0.1 mg/mL CaneCPI-5 (Cg + Cane). Volunteers wore an appliance containing 4 specimens. Once/day, they applied the gel (except for Nt) (4 min/specimen). Erosive challenges were performed extra-orally (0.1% citric acid, 90 s, 4 × /day; ERO). Specimens were also abraded (toothbrush, 15 s/specimen, 2 × /day; ERO + ABR). Enamel wear was assessed by profilometry and relative surface reflection intensity (%SRI). Two-way RM-ANOVA/Sidak's tests and Spearman's correlation were used (p < 0.05). RESULTS: For profilometry, ERO + ABR promoted significantly greater wear when compared with ERO. There was a significant difference among all treatments. The lowest enamel loss occurred for Cg + Cane, followed by Cg + NaF, Cg, and Nt (p < 0.05). The %SRI was significantly lower for ERO + ABR when compared to ERO, only for the Nt group. The greatest %SRI was found for the Cg + NaF and Cg + Cane groups, which did not differ significantly, regardless of the conditions. The lowest %SRI was found for the Nt and Cg groups, which did not differ from each other, regardless of the conditions. The Nt group did not differ significantly from the Cg + NaF (ERO). There was a significant correlation between both analyses. CONCLUSION: The incorporation of CaneCPI-5 in the chitosan gel prevented erosive wear in situ. CLINICAL RELEVANCE: These results open a new perspective for the use of CaneCPI-5 in other application vehicles, such as chitosan gel.

Pellicle modification with natural bioproducts: Influence on tooth color under erosive conditions.

Salivary pellicle was modified with bioproducts and we assessed the change in tooth color and the protection of enamel to erosion. Human enamel specimens were assigned to one of three solutions: grape seed extract or black tea (bioproducts), or deionized water (negative control); after which one half the specimens underwent erosive challenges. The specimens underwent 15 cycles involving salivary pellicle formation (10 min, 37°C), incubation in solution (2 min, 25°C), subsequent pellicle formation (90 min, 37°C). Half of the specimens was kept in a humid chamber and the other half was submitted to erosion (2 min, 1% citric acid). After 15 such cycles, the pellicle was removed. Tooth color and the surface reflection intensity were assessed after every five cycles and after pellicle removal. For non-eroded specimens, the exposure to bioproducts promoted significantly greater color change than the deionized water, with increases in yellow appearance. After pellicle removal, the color was similar in all non-eroded specimens. The bioproducts increased the surface reflection intensity over cycles. For the erosion-exposed specimens, erosion itself resulted in color change. Black tea and deionized water resulted in increased yellow appearance. Exposure to the bioproducts resulted in higher relative surface reflection intensity values over time, but only grape seed extract resulted in higher relative surface reflection intensity value at the time of pellicle removal. The bioproducts caused transient staining effect, which was reduced after pellicle removal. For enamel submitted to erosion, grape seed extract resulted in less color change and better protection of enamel against erosion than black tea or water.

Acquired Pellicle Engineering Using a Combination of Organic (Sugarcane Cystatin) and Inorganic (Sodium Fluoride) Components against Dental Erosion.

This study evaluated the combination of a sugarcane cystatin (CaneCPI-5) and sodium fluoride (NaF) in acquired pellicle engineering for the prevention of dental erosion in vitro. Seventy-five human enamel specimens were prepared and divided into 5 treatment groups (n = 15/group): Deionized water (Control); Elmex™ (SnCl2/NaF/AmF); 0.1 mg/mL CaneCPI-5; 500 ppm NaF; and CaneCPI-5+NaF (Combination). The specimens were individually treated (200 µL; 2 min; 37°C), then incubated in human saliva (200 µL; 1 h, at 37°C) for acquired pellicle formation. Afterward, the specimens were submitted to an erosive challenge (1% citric acid [CR], pH 3.6, 10 mL, 2 min, 25 °C). This sequence was conducted 5 times. Percentage of surface microhardness change (%SMC), relative surface reflection intensity (rSRI), and calcium released to the CR were measured and analyzed by one-way ANOVA followed by Tukey's test (p < 0.05). In general, all the treatments (SnCl2/NaF/AmF, CaneCPI-5, NaF, and Combination) significantly protected the enamel when compared the control group. Regarding %SMC and rSRI, the Combination was the most effective treatment, reducing the %SMC significantly (p < 0.01) when compared to all the other treatments, although this difference was not significant in the CR analysis. All treatments demonstrated a protective effect on enamel against dental erosion; however, the combination of CaneCPI-5 with NaF showed a greater protection.

Salivary Pellicle Modification with Grape-seed Extract: In Vitro Study on the Effect on Bacterial Adhesion and Biofilm Formation.

PURPOSE: Grape-seed extract (GSE) contains polyphenols that readily adhere to proteins and modify the acquired enamel pellicle (AEP). The first step in biofilm formation is bacterial adhesion to the AEP-covered enamel. The aim of this in vitro study was to test whether AEP modification with GSE, fluoride (F-), or their combination (GSE+F-) modulates bacterial adhesion, biofilm metabolism and composition, or cariogenic demineralisation of the enamel. MATERIALS AND METHODS: The study comprised 3 parts: 1) single-strain Streptococcus gordonii species, 2) a five-species biofilm model, or 3) biofilm (re-)formation using the five-species biofilm model after removal of initial biofilm with toothbrushing. Human whole-mouth stimulated saliva was used to form an AEP on human enamel specimens. The AEP was incubated in water (control), or modified with GSE, F-, or GSE+F-. Bacterial adhesion, biofilm diversity, metabolic activity, biofilm mass, and cariogenic demineralisation (surface hardness) of enamel were assessed after incubation in bacterial broths after 4 h or 22 h. Differences between groups were analysed with one-way ANOVA and post-hoc Bonferroni tests. RESULTS: GSE and GSE+F- statistically significantly decreased single-strain S. gordonii adhesion, but had no relevant influence when the five-species biofilm model was used. In the biofilm (re-)formation model, GSE reduced bacterial adhesion compared to GSE+F-, while F- caused less cariogenic demineralisation than was found in the control group. CONCLUSION: AEP modified with GSE retards S. gordonii adhesion, but it does not influence the formation, metabolism and composition of a cariogenic multi-species biofilm.

Acquired pellicle engineering with proteins/peptides: Mechanism of action on native human enamel surface.

OBJECTIVE: This study investigated the mechanism of action of different proteins/peptides (separately or in combination), focusing on how they act directly on the native enamel surface and on modifying the salivary pellicle. METHODS: A total of 170 native human enamel specimens were prepared and submitted to different treatments (2 h; 37 °C): with deionized water, CaneCPI-5, Hemoglobin, Statherin, or a combination of all three proteins/peptides. The groups were subdivided into treatment acting on the enamel surface (NoP - absence of salivary pellicle), and treatment modifying the salivary pellicle (P). Treatment was made (2 h; 37 °C) in all specimens, and later, for P, the specimens were incubated in human saliva (2 h; 37 °C). In both cases, the specimens were immersed in 1% citric acid (pH 3.6; 2 min; 25 °C). Calcium released from enamel (CaR) and its relative surface reflection intensity (%SRI) was measured after 5 cycles. Between-group differences were verified with two-way ANOVA, with "presence of pellicle" and "treatment" as factors (α = 0.05). RESULTS: The presence of pellicle provided better protection regarding %SRI (p < 0.01), but not regarding CaR (p = 0.201). In relation to treatment, when compared to the control group, all proteins/peptides provided significantly better protection (p < 0.01 for %SRI and Car). The combination of all three proteins/peptides demonstrated the best protective effect (p < 0.01 for %SRI). CONCLUSION: Depending on the protein or peptide, its erosion-inhibiting effect derives from their interaction with the enamel surface or from modifying the pellicle, so a combination of proteins and peptides provides the best protection. CLINICAL SIGNIFICANCE: The present study opens a new direction for a possible treatment with a combination of proteins for native human enamel, which can act directly on the enamel surface as well on the modification of the salivary pellicle, for the prevention of dental erosion.

Salivary pellicle modification with polyphenol-rich teas and natural extracts to improve protection against dental erosion.

OBJECTIVE: To investigate the modification of the salivary pellicle with different polyphenol-rich teas and natural extracts for the protection against dental erosion. METHODS: We performed two experiments: one with teas (Green tea, Black tea, Peppermint tea, Rosehip tea, negative control [NC]) and other with natural extracts (Grape seed, Grapefruit seed, Cranberry, Propolis, NC), where NC was deionized water. A total of 150 enamel specimens were used (n = 15/group). Both experiments followed the same design, consisting of 5 cycles of: salivary pellicle formation (30 min, 37 °C), modification with the solutions (30 min, 25 °C), further salivary pellicle formation (60 min, 37 °C) and erosive challenge (1 min, 1% citric acid, pH 3.6). Relative surface microhardness (rSMH), relative surface reflection intensity (rSRI) and amount of calcium release (CaR) were evaluated. Data were analysed with Kruskal-Wallis and Wilcoxon rank sum tests with Bonferroni correction (α = 0.05). RESULTS: Regarding teas, Black and Green teas showed the best protection against dental erosion, presenting higher rSMH and lower CaR than NC. Peppermint tea was not different to NC and Rosehip tea caused erosion, showing the highest CaR and greatest loss of SMH and SRI. Regarding natural extracts, Grape seed and Grapefruit seed extracts presented the best protective effect, with significantly higher rSMH and lower CaR. Cranberry caused significantly more demineralization; and Propolis did not differ from NC. CONCLUSION: Green tea, Black tea, Grape seed extract and Grapefruit seed extract were able to modify the salivary pellicle and improve its protective effect against enamel erosion, but Rosehip tea and Cranberry extract caused erosion. CLINICAL RELEVANCE: Some some bio-products, such as teas and natural extracts, improve the protective effect of the salivary pellicle against enamel erosion. More studies should be performed in order to test the viability of their use as active ingredients for oral care products.

Proteomics of acquired pellicle in gastroesophageal reflux disease patients with or without erosive tooth wear.

OBJECTIVES: This in vivo study compared the protein profile of the acquired enamel pellicle (AEP) in volunteers 1) with gastroesophageal reflux disease (GERD) and erosive tooth wear (ETW) (BEWE ≥ 9; GE group); 2) with GERD without ETW (BEWE = 0; GNE group) and 3) control (without GERD and BEWE = 0; C group). MATERIALS AND METHODS: Twenty-four subjects (8/group) participated. AEP was formed during 120 min and collected. After protein extraction, the samples were submitted to reverse phase liquid chromatography coupled to mass spectrometry. Label-free proteomic quantification was performed using Protein Lynx Global Service software. RESULTS: In total, 458 proteins were identified. Seventy-six proteins were common to all the groups. The proteomic profile of the AEP was quite different among the distinct groups. The numbers of proteins exclusively found in the C, GE and GNE groups were 113, 110 and 81, respectively. Most of the proteins exclusively identified in the C and GNE groups bind metals, while those in the GE group are mainly membrane proteins. Many proteins were found exclusively in the reflux groups. In the quantitative analyses, when the GNE group was compared with the GE group, the proteins with the highest decreases were Lysozyme C, Antileukoproteinase, Cathepsin G, Neutrophil defensins and Basic salivary proline-rich proteins, while those with the highest increases were subunits of Hemoglobin, Albumin and isoforms of Cystatin. CONCLUSION: Profound alterations in the proteomic profile of the AEP were seen in GNE compared with GE volunteers, which might play a role in the resistance to ETW seen in the first. CLINICAL SIGNIFICANCE: This pioneer study compared the proteomic profile of the AEP of patients with GERD with or without ETW. Increased proteins in those without ETW might be protective and are good candidates to be added to dental products to protect against erosion caused by intrinsic acids.

Factors for determining dental anxiety in preschool children with severe dental caries

Abstract The aim of this study was to assess the clinical and socioeconomic indicators associated with dental anxiety in preschool children with severe dental caries. A total of 100 children between 3 and 5 years of age were selected during a dental screening procedure. The selection criteria were having at least one tooth with dental caries and a visible pulpal involvement, ulceration, fistula, and abscess (PUFA) index of ≥1 in primary teeth. Before the clinical examination or any treatment procedure was performed, we evaluated the children’s dental anxiety using the Facial Image Scale (FIS). Parents completed a questionnaire on socioeconomic conditions, which included the family structure, number of siblings, parental level of education, and family income. A dentist blinded to FIS and socioeconomic data performed the clinical examination. Poisson regressions associate clinical and socioeconomic conditions with the outcome. Most of the children (53%) experienced extensive dental caries (dmf-t ≥ 6), and all children had severe caries lesions, with a PUFA index of ≥1 in 41% and that of ≥2 in 59%. The multivariate adjusted model showed that older children (4–5-year old) experienced lower dental anxiety levels compared with younger children (3-year old) (RR = 0.35; 95%CI: 0.17–0.72 and RR = 0.18; 95%CI: 0.04–0.76, respectively), and children with three or more siblings were associated with higher levels of dental anxiety (RR = 2.27; 95%CI: 1.06–4.87). Older age is associated with low dental anxiety, and more number of siblings is associated with high dental anxiety in preschool children, whereas the severity or extent of dental caries is not associated with dental anxiety.

Fluoride varnishes with calcium glycerophosphate: fluoride release and effect on in vitro enamel demineralization

The aims of this study were (1) to assess the amount of fluoride (F) released from varnishes containing calcium glycerophosphate (CaGP) and (2) to assess the effect of the experimental varnishes on in vitrodemineralization. Six test groups using 5 varnishes: base varnish (no active ingredients); Duraphat® (2.26% NaF); Duofluorid® (5.63% NaF/CaF2); experimental varnish 1 (1% CaGP/5.63% NaF/CaF2); experimental varnish 2 (5% CaGP/5.63% NaF/CaF2); and no varnish were set up. In stage 1, 60 acrylic blocks were randomly distributed into 6 groups (n = 10). Then 300 µg of each varnish was applied to each block. The blocks were immersed in deionized water, which was changed after 1, 8, 12, 24, 48 and 72 hours. Fluoride concentration in the water was analyzed using a fluoride electrode. In stage 2, 60 bovine enamel samples were distributed into 6 groups (n = 10), and treated with 300 µg of the respective varnish. After 6 h the varnish was removed and the samples were subjected to a 7-day in vitro pH cycle (6 h demineralization/18 h remineralization per day). The demineralization was measured using surface hardness. The results showed that both experimental varnishes released more fluoride than Duofluorid® and Duraphat® (p < 0.05), but Duraphat® showed the best preventive effect by decreasing enamel hardness loss (p < 0.05). Therefore, we conclude that even though (1) the experimental varnishes containing CaGP released greater amounts of F, (2) they did not increase in the preventive effect against enamel demineralization.

Association between parental guilt and oral health problems in preschool children

Parents may feel guilty about their children's oral problems, which can affect their quality of life. The aim of this study was to assess the presence of parental guilt and its association with early childhood caries (ECC), traumatic dental injuries (TDI) and malocclusion (AMT) in preschool children. All 2 to 5 year-old children (N = 305), and their parents, seeking dental care at the University of São Paulo Dental School one-week Screening Programme, were asked to participate in the study, and 260 agreed. Children were examined by two calibrated dentists, and their parents answered a socioeconomic and ECOHIS questionnaire; the question on guilt was used as the dependent variable. Regression analyses examined the association between parental guilt and ECC, TDI, AMT and socioeconomic factors. A total of 35.8% of parents felt guilty. This was only associated with caries severity. No association was found between guilt and TDI, AMT or socioeconomic factors. ECC was present in 63.8% of the children; the mean (± sd) dmf-t score was 7.29 (± 2.78). Thus, the number of parents feeling guilty increases with the increase of their children's dental caries severity. Parental guilt is related to caries but is not associated with TDI or AMT.

Diagnóstico, prevenção e tratamento clínico da erosão dentária / Clinical diagnasis, preventian and treatment af dental erosian

Estudos epidemiológicos recentes evidenciam um aumento na prevalência de erosão dentária em vários países, principalmente entre crianças e adolescentes. O diagnóstico precoce das lesões erosivas viabiliza a instituição de medidas preventivas logo no início do processo de perda de estrutura dentária, evitando procedimentos reabilitadores extensos. Porém, o diagnóstico diferencial entre a abrasão, a atrição e a erosão dentárias ainda é um assunto controverso entre os clínicos e os pesquisadores, sendo necessário estabelecer critérios claros para distinção entre as características destes tipos de lesões. Uma vez diagnosticada a erosão dentária, terapias preventivas e restauradoras são necessárias e diversas pesquisas têm sido geradas com este propósito nos últimos anos. Portanto, o presente trabalho se propõe a apresentar uma revisão baseada nas evidências científicas encontradas na literatura sobre o diagnóstico e o tratamento da erosão dentária.

Recent epidemiological studies revealed an increase in the prevalence of dental ero- sion around the world, mainly among children and teenagers. Early diagnosis of erosive lesions enables the implementation of preventive measures at the beginning of process of dental structure loss, thus avoiding the need for extensive rehabilitation procedures. However, differential diagnosis of dental abrasion, attrition and erosion remains a con- troversial issue among clinicians and researchers. Therefore, there is a need to establish clear criteria to make it possible to distinguish between the different characteristics of each type of tooth wear lesion. Once dental erosion is diagnosed, preventive and res- torative procedures are needed and a variety of researches have been published on this subject. Thus, the present paper aims to review concepts of dental erosion diagnosis and treatment, based on the scientific evidence found in literature.