Enamel Demineralization Research Articles

In Vitro Effect of Streptococcus mutans Biofilm Produced in Sugar-Free Coca-Cola on Enamel

ObjectiveSugary drinks such as Coca-Cola may expedite dental caries. For this reason, sugar-free drinks like Coca-Cola Zero Sugar (CZ) may be considered advantageous. This research aims to evaluate in vitro the CZ effect in the presence of Streptococcus mutans (S. mutans) biofilm on enamel demineralization. MethodsNinety-six human enamel slabs (4 × 4 mm) were used. S. mutans UA-159 72-hour biofilm was created over enamel surfaces. The specimens were soaked in CZ, HCl, or 10% sucrose in PBS solution, 3 times a day for 15 minutes over the course of 4 days. Viable counts (CFU/mL) and biofilm biomass (Crystal Violet staining) were evaluated. pH was measured after each exposure. After 4 days, Demineralization was evaluated clinically and by Vickers microhardness tests. Slabs were photographed using a stereomicroscope before and after exposure to caries-promoting conditions. ResultsSlabs that were soaked in CZ showed an increase in viable counts compared to control and almost similar counts with 10% sucrose in PBS solution exposures (1010and109CFUmL, respectivly). Biofilm biomass tests showed a 25% higher bacterial growth in the CZ group. CZ pH measures were the lowest and the only group to show a decrease in pH over time (pH ∼3). Enamel slabs that were evaluated clinically in the stereomicroscope postexposures had a chalky and matt appearance as opposed to their shiny appearance in the baseline evaluation. ConclusionsCZ creates a favourable environment for the growth of S. mutans. It may be suggested that even though CZ is sugar free it has a cariogenic effect on enamel. Clinical significanceClinicians need to educate patients that sugar-free carbonated drinks may be just as harmful as regular carbonated drinks, and hence avoided. This research emphasizes the harmful effect sugar-free carbonated drinks on teeth and sheds new light on their cariogenic potential.

Efficacy of peptide-based enamel coatings in the prevention of demineralization using fixed orthodontic brackets in a rat model

White spot lesions (WSLs) represent a prominent pathology encountered during orthodontic treatment, originating from enamel demineralization induced by the accumulation of bacterial biofilms. The previously developed bioinspired enamel coating form of self-assembling antimicrobial peptide D-GL13K exhibited antimicrobial activity and enhanced acid impermeability, offering a potential solution to prevent demineralization. The primary aim of this investigation is to assess the invivo anti-demineralization properties and biocompatibility of the D-GL13K coating. A rat model was developed to assess the antimicrobial enamel coating during fixed orthodontic treatment. The anti-demineralization efficacy attributed to the D-GL13K coating was evaluated by employing optical coherence tomography, Vickers microhardness testing, and scanning electron microscopy. The biocompatibility of the D-GL13K coating was investigated through histologic observations of vital organs and tissues using hematoxylin and eosin. The D-GL13K coating demonstrated significant anti-demineralization effects, evidenced by reduced demineralization depth analyzed through optical coherence tomography and enhanced Vickers hardness than in the noncoated control group, showcasing the coating's potential to protect teeth from WSLs. Scanning electron microscopy analysis further elucidated the diminished enamel damage observed in the group treated with D-GL13K. Importantly, histologic examination of vital organs and tissues using hematoxylin and eosin staining revealed no overt disparities between the D-GL13K coated group and the noncoated control group. The D-GL13K enamel coating demonstrated promising anti-demineralization and biocompatibility properties in a rat model, thereby suggesting its potential for averting WSLs after orthodontic interventions. Further research in human clinical settings is needed to evaluate the coating's long-term efficacy.

Hydrated Calcium Silicate in Resin Composites for Prevention of Secondary Caries

Introduction and aimsThe gaps at the margins of restorative composite resin can increase as the carious process occurs underneath the materials, causing further demineralization along the tooth cavity wall. The aim of this study was to evaluate the effects of restorative resin composite containing hydrated calcium silicate (hCS) filler on enamel protection against demineralization by simulating microleakage between the test material and teeth in a cariogenic environment. MethodsThe experimental resin composites were composed of 70 wt.% filler, which was mixed with a glass filler and hCS in a weight ratio of 70.0% glass (hCS 0), 17.5% hCS + 52.5% glass (hCS 17.5), 35.0% hCS + 35.0% glass (hCS 35.0), and 52.5% hCS + 17.5% glass (hCS 52.5). A light-cured experimental resin composite disk was positioned over a polished bovine enamel disk, separated by a 30-µm gap, and immersed in artificial saliva with pH 4.0 for 15, 30, and 60 days. After the immersion period, the enamel disk was separated from the resin composite disk and evaluated using a microhardness tester, atomic force microscopy, and polarized light microscopy. The opposing sides of the enamel and resin composite disks were observed using scanning electron microscopy/energy dispersive X-ray spectrometry. ResultsThe enamel surface showed a significant increase in microhardness, decreased roughness, and remineralization layer as the proportion of hCS increased (P < .05). In the scanning electron microscopy image, the enamel surface with hCS 35.0 and 52.5 after all experimental immersion periods, showed a pattern similar to that of a sound tooth. ConclusionsThe results demonstrated that increasing the hCS filler level of restorative resin composites significantly decreased enamel demineralization. Clinical relevanceHydrated calcium silicate laced restorative resin composites may be a promising dental biomaterial for protecting teeth against demineralization and preventing secondary caries around restorations.

Investigation of mechanical properties, remineralization, antibacterial effect, and cellular toxicity of composite orthodontic adhesive combined with silver-containing nanostructured bioactive glass

BackgroundThe formation of white spots, which represent early carious lesions, is a major issue with fixed orthodontics. The addition of remineralizing agents to orthodontic adhesives may prevent the formation of white spots. The aim of this study was to produce a composite orthodontic adhesive combined with nano-bioactive glass-silver (nBG@Ag) for bracket bonding to enamel and to investigate its cytotoxicity, antimicrobial activity, remineralization capability, and bond strength.MethodsnBG@Ag was synthesized using the sol-gel method, and characterized using transmission electron microscopy (TEM), X-ray diffraction (XRD), and Fourier-transform infrared spectroscopy with an attenuated total reflectance attachment (ATR-FTIR). The cytotoxicity test (MTT) and antimicrobial activity of adhesives containing 1%, 3%, and 5% (wt/wt) nBG@Ag were evaluated, and the shear bond strength of the adhesives was measured using a universal testing machine. Remineralization was assessed through microhardness testing with a Vickers microhardness tester and scanning electron microscopy (SEM). Statistical analyses were conducted using the Shapiro-Wilk test, Levene test, one-way ANOVA, Robust-Welch test, Tukey HSD method, and two-way ANOVA.ResultsThe biocompatibility of the adhesives was found to be high, as confirmed by the lack of significant differences in the cytotoxicity between the sample and control groups. Discs made from composites containing nBG@Ag exhibited a significant reduction in the growth of Streptococcus mutans (p < 0.05), and the antibacterial activity increased with higher percentages of nBG@Ag. The shear bond strength of the adhesives decreased significantly (p < 0.001) after the addition of nanoparticles, but it remained above the recommended value. The addition of nBG@Ag showed improvement in the microhardness of the teeth, although the differences in microhardness between the study groups were not statistically significant. The formation of hydroxyapatite deposits on the tooth surface was confirmed through SEM and energy-dispersive X-ray spectroscopy (EDX).ConclusionAdding nBG@Ag to orthodontic adhesives can be an effective approach to enhance antimicrobial activity and reduce enamel demineralization around the orthodontic brackets, without compromising biocompatibility and bond strength.

Preparation and performance evaluation of a novel orthodontic adhesive incorporating composite dimethylaminohexadecyl methacrylate-Polycaprolactone fibers.

This study addressed enamel demineralization, a common complication in fixed orthodontic treatment, by evaluating a novel orthodontic adhesive with DMAHDM-PCL composite fibers. These fibers, produced through electrospinning, were incorporated into orthodontic adhesive to create experimental formulations at different concentrations and a control group. The study assessed antimicrobial properties, biosafety, and mechanical characteristics. New orthodontic adhesive exhibited significant bacteriostatic effects, reducing bacterial biofilm activity and concentrations. Incorporating 1% and 3% DMAHDM-PCL did not affect cytocompatibility. Animal tests confirmed no inflammatory irritation. Shear bond strength and adhesive residual index results indicated that antimicrobial fibers didn't impact bonding ability. In conclusion, orthodontic adhesives with 3% DMAHDM-PCL fibers are potential antimicrobial bonding materials, offering a comprehensive solution to enamel demineralization in orthodontic patients.

Chitosan Phytate Nanoparticles: A Synergistic Strategy for Effective Dental Caries Prevention.

Dental caries is a widespread oral disease that poses a significant medical challenge. Traditional caries prevention methods, primarily the application of fluoride, often fall short in effectively destroying biofilms and preventing enamel demineralization, thereby providing limited efficacy in halting the progression of caries over time. To address this issue, we have developed a green and cost-effective synergistic strategy for the prevention of dental caries. By combining natural sodium phytate and chitosan, we have created chitosan-sodium phytate nanoparticles that offer both the antimicrobial properties of chitosan and the enamel demineralization-inhibiting capabilities of sodium phytate. In an ex vivo biofilm model of human teeth, we found that these nanoparticles effectively prevent biofilm buildup and acid damage to the mineralized tissue. Additionally, topical treatment of dental caries in rodent models has shown that these nanoparticles effectively suppress disease progression without negatively impacting oral microbiota diversity or causing harm to the gingival-mucosal tissues, unlike traditional prevention methods.

Enhanced anti-biofilm and anti-caries potential of arginine combined with calcium glycerophosphate and fluoride

ObjectiveThe aim of this work was to evaluate the antibiofilm and anticaries properties of the association of arginine (Arg) with calcium glycerophosphate (CaGP) and fluoride (F). MethodsAn active attachment, polymicrobial biofilm model obtained from saliva and bovine teeth discs were used. After the initial biofilm growth period, the enamel discs were transferred to culture medium. The treatment solutions were added to the culture media to achieve the desired final concentration. The following groups were used: negative control (Control); F (110 ppm F); CaGP (0.05 %); Arg (0.8 %) and their associations (F + CaGP; Arg + F; Arg + CaGP; Arg +F + CaGP). The following analyses were carried out: bacterial viability (total bacteria, aciduric bacteria and mutans streptococci), pH assessment of the spent culture medium, dry weight quantification, evaluation of surface hardness loss (%SH) and subsurface mineral content. Normality and homoscedasticity were tested (Shapiro-Wilk and Levene's test) and the following tests were applied: two-way ANOVA (acidogenicity), Kruskall-Wallis (microbial viability) and one way ANOVA (dry weight, %SH, mineral content). ResultsThe association Arg + F + CaGP resulted in the lowest surface hardness loss in tooth enamel (-10.9 ± 2.3 %; p < 0.05). Arg +F + CaGP exhibited highest values of subsurface mineral content (10.1 ± 2.9 gHAP/cm3) in comparison to Control and F (p < 0.05). In comparison to Control and F, Arg +F + CaGP promoted the highest reduction in aciduric bacteria and mutans streptococci (5.7 ± 0.4; 4.4 ± 0.5 logCFU/mL, p < 0.05). ConclusionsThe Arg-F-Ca association demonstrated to be the most effective combination in protecting the loss of surface hardness and subsurface mineral content, in addition to controlling important virulence factors of the cariogenic biofilm. Clinical significanceOur findings provide evidence that the Arg-F-Ca association showed an additive effect, particularly concerning protection against enamel demineralization. The combination of these compounds may be a strategy for patients at high risk of caries.

Effectiveness of fluoride mouthrinse in prevention of demineralization during fixed orthodontic treatment: A systematic review and meta-analysis.

Enamel demineralization is a very common occurrence around bonded brackets in an orthodontic practice. Fluoride (FLR) applications have been used to prevent decalcification and further progression of white spot lesions. The purpose of this systematic review and meta-analysis was to systematically appraise available literature on the effectiveness of fluoride mouthrinse in the prevention of demineralization around fixed orthodontic appliances. A search was conducted for randomized controlled clinical trials among four electronic databases (MEDLINE, Google Scholar, PubMed, and Cochrane Review) through MeSH terms and keywords. Studies were excluded if random allocation was not conducted, or if they were animal or in vitro studies. About 146 articles were screened and 5 studies were selected for the present review. Only two studies were selected for MA due to variations in the measurement of outcomes among studies. This review concluded that rinsing with FLR in the course of the fixed orthodontic treatment lessens demineralization around the bracket. Using FLR mouthrinse to inhibit the formation of white spot lesions or dental caries in patients with multiple cavities or restoration can be considered in clinical practice.

Bond Integrity and Microleakage of Orthodontic Bands Cemented by Glass Ionomer Cements Stored in Static Magnetic Field

Aim: Improving the band-tooth bond integrity by glass ionomer cement (GIC) is essential in orthodontic treatments. As, microleakage under bands induced enamel demineralization. Storing the dental material to updated magnets improved their mechanical properties. This research aimed to assess the microleakage of GIC after storing in a static magnetic field (SMF). Material and Methods: Forty premolars and their suitable bands were randomly classified into two main groups according to the types of GIC tested in this research; resin-modified GIC (RMGIC) and conventional GIC (CGIC). Each group was subdivided according to the exposure to SMF before polymerization into two subgroups. CGIC not exposed to SMF (CC), CGIC exposed to SMF (CM), RMGIC not exposed to SMF (LC) and RMGIC exposed to SMF (LM). SMF intensity performed was 0.225 Tesla, exposed for 48 hours at room temperature. The entire tube of RMGIC was inserted in SMF, where the powder of CGIC was stored in SMF. The microleakage under the band was evaluated under a 20× stereomicroscope by dye penetration technique at the cement band interface. Wilcoxon signed-rank test was used for data analysis, p ≤ .05. Results: The main (SD) microleakage of GIC reduced significantly ( p = .043) after being exposed to SMF from 3.1950 (0.632) mm to 1.7095 (0.1176) mm and from 0.8745 (0.1104) mm to 0.6430(0.094) mm for CGIC and RMGIC, respectively. Conclusion: Storing the CGIC powder in (0.225 T) SMF improves band-tooth bond integrity. Additionally, the preservation of RMGIC in SMF minimized the microleakage under orthodontic bands.

Dynamics of Dental Enamel Surface Remineralization under the Action of Toothpastes with Substituted Hydroxyapatite and Birch Extract.

To address tooth enamel demineralization resulting from factors such as acid erosion, abrasion, and chronic illness treatments, it is important to develop effective daily dental care products promoting enamel preservation and surface remineralization. This study focused on formulating four toothpastes, each containing calcined synthetic hydroxyapatite (HAP) in distinct compositions, each at 4%, along with 1.3% birch extract. Substitution elements were introduced within the HAP structure to enhance enamel remineralization. The efficacy of each toothpaste formulation was evaluated for repairing enamel and for establishing the dynamic of the remineralization. This was performed by using an in vitro assessment of artificially demineralized enamel slices. The structural HAP features explored by XRD and enamel surface quality by AFM revealed notable restorative properties of these toothpastes. Topographic images and the self-assembly of HAP nanoparticles into thin films on enamel surfaces showcased the formulations' effectiveness. Surface roughness was evaluated through statistical analysis using one-way ANOVA followed by post-test Bonferroni's multiple comparison test with a p value < 0.05 significance setting. Remarkably, enamel nanostructure normalization was observed within a short 10-day period of toothpaste treatment. Optimal remineralization for all toothpastes was reached after about 30 days of treatment. These toothpastes containing birch extract also have a dual function of mineralizing enamel while simultaneously promoting enamel health and restoration.

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.

This study was designed in two-legs. In the in vivo, we explored the potential of a rinse solution containing a combination (Comb) of 0.1mg/mL CaneCPI-5 (sugarcane-derive cystatin), 1.88 × 10- 5M StN15 (statherin-derived peptide) and 1.0mg/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. In vivo study, 10 participants rinsed (10mL,1min) with either deionized water (H2O-control) or Comb. AEP and biofilm were collected after 2 and 3h, respectively, after rinsing. AEP samples underwent proteomics analysis, while biofilm microbiome was assessed via 16S-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. 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. The AEP modification altered the subsequent layers, affecting the initial process of bacterial adhesion of pathogenic and commensal bacteria, as well as enamel demineralization. Comb group shows promise in shaping oral health by potentially introducing innovative approaches to prevent enamel demineralization and deter tooth decay.

Arginine and sodium fluoride affect the microbial composition and reduce biofilm metabolism and enamel mineral loss in an oral microcosm model

ObjectiveTo assess the effects of arginine, with or without sodium fluoride (NaF; 1,450 ppm), on saliva-derived microcosm biofilms and enamel demineralization. MethodsSaliva-derived biofilms were grown on bovine enamel blocks in 0.2 % sucrose-containing modified McBain medium, according to six experimental groups: control (McBain 0.2 %); 2.5 % arginine; 8 % arginine; NaF; 2.5 % arginine with NaF; and 8 % arginine with NaF. After 5 days of growth, biofilm viability was assessed by colony-forming units counting, laser scanning confocal microscopy was used to determine biofilm vitality and extracellular polysaccharide (EPS) production, while biofilm metabolism was evaluated using the resazurin assay and lactic acid quantification. Demineralization was evaluated by measuring pH in the culture medium and calcium release. Data were analyzed by Kruskal-Wallis’ and Dunn's tests (p < 0.05). Results8 % arginine with NaF showed the strongest reduction in total streptococci and total microorganism counts, with no significant difference compared to arginine without NaF. Neither 2.5 % arginine alone nor NaF alone significantly reduced microbial counts compared to the control, although in combination, a reduction in all microbial groups was observed. Similar trends were found for biofilm vitality and EPS, and calcium released to the growth medium. Conclusions8 % Arginine, with or without NaF, exhibited the strongest antimicrobial activity and reduced enamel calcium loss. Also, NaF enhanced the effects of 2.5 % arginine, yielding similar results to 8 % arginine for most parameters analyzed. Clinical significanceThe results provided further evidence on how arginine, with or without NaF, affects oral microcosm biofilms and enamel mineral loss.

Management of enamel demineralization- An iatrogenic effect of orthodontic treatment: A case report

Areas of demineralised enamel, usually referred to as white spot lesions (WSLs), constitute to a clinical problem in Orthodontics following treatment with fixed appliances. They result due to an imbalance between de- and remineralisation of enamel, caused by the inter-relationship of several factors. This manuscript is intended to elucidate the presentation of a clinical case treated with orthodontic braces with 10-year follow up, and management of demineralization with veneers that occurred due to long term fixed orthodontic treatment. The goal of treatment has been achieved according to patient’s desire and satisfactory digital veneer placement. No further relapse has been seen in the follow up. The treatment resulted in an aesthetic, functional, and stable occlusion, along with improved facial profile.

Enamel changes of bleached teeth following application of an experimental combination of chitosan-bioactive glass

BackgroundConsidering the extensive use of bleaching agents and the occurrence of side effects such as enamel demineralization, this study aimed to assess the enamel changes of bleached teeth following the experimental application of chitosan-bioactive glass (CH-BG).MethodsIn this in vitro study, CH-BG (containing 66% BG) was synthesized and characterized by Fourier-transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). Thirty sound human premolars were bleached with 40% hydrogen peroxide, and the weight% of calcium and phosphorus elements of the buccal enamel surface was quantified before and after bleaching by scanning electron microscopy/ energy-dispersive X-ray spectroscopy (SEM, EDX). Depending on the surface treatment of the enamel surface, the specimens were divided into three groups (n = 10): control (no treatment), MI Paste (MI), and CH-BG. Then the specimens were stored in artificial saliva for 14 days. The SEM/EDX analyses were performed again on the enamel surface. Data were analyzed by one-way ANOVA and Tukey’s test and a p-value of < 0.05 was considered statistically significant.ResultsIn all groups, the weight% of calcium and phosphorus elements of enamel decreased after bleaching; this reduction was significant for phosphorus (p < 0.05) and insignificant for calcium (p > 0.05). After 14 days of remineralization, the weight% of both calcium and phosphorus elements was significantly higher compared to their bleached counterparts in both MI and CH-BG groups (p < 0.05). Following the remineralization process, the difference between MI and CH-BG groups was not significant (p > 0.05) but both had a significant difference with the control group in this regard (p < 0.05).ConclusionsThe synthesized CH-BG compound showed an efficacy comparable to that of MI Paste for enamel remineralization of bleached teeth.

The erosive effect of pomegranate juice on enamel: An in vitro study.

Dental erosion is a chemical-mechanical process that leads to the loss of dental hard tissues. This study aimed to investigate the effect of pomegranate juice on the enamel. Enamel blocks were randomly divided into three groups: deionized water, cola, and pomegranate juice. The blocks were immersed in the solutions four times a day for 14 days, and stored in artificial saliva for the remaining period. The surface hardness was measured on days 7 and 14. The surface structures of the demineralized blocks were observed via scanning electron microscopy (SEM), and the depth of demineralization was observed via confocal laser scanning microscopy (CLSM). The pH, calcium, and phosphorus levels of the three solutions were analyzed. The microhardness values of the blocks in the pomegranate juice and cola groups decreased with the increase in the demineralization time. The blocks in the pomegranate juice group exhibited large fractures in the enamel column, whereas those in the cola group had pitted enamels with destruction of the interstitial enamel column. Compared with cola group, fluorescent penetration increased in pomegranate juice (P < 0.01). The pH of cola (2.32 ± 0.09) was lower than that of pomegranate juice (3.16 ± 0.16). Furthermore, the calcium content in pomegranate juice was significantly higher than that in cola (P < 0.01). Alternatively, the concentration of phosphorous in cola was significantly higher than that in pomegranate juice (P < 0.01). These findings indicate that pomegranate juice can cause enamel demineralization with an erosive potential comparable to that of cola.

Efficacy of pit and fissure sealant containing S-PRG filler on inhibition of enamel demineralization

The aim of this in-vitro study was evaluating the effectiveness of an S-PRG filler containing fissure sealant (Beautisealant) to inhibit enamel demineralization and to compare it with two different fluoride-containing (Helioseal-F) and non-fluoride-based (Helioseal) conventional fissure sealants, using enamel microhardness tester. Material and Methods: In this study 30 caries-free 3rd molar teeth were used. Helioseal, Helioseal-F or Beautisealant fissure sealant was applied to the buccal surfaces of the teeth and subjected to a 14-day pH cycle. Lingual surfaces were the control group. Sections were taken in the bucco-lingual direction and cross-sectional microhardness values were measured at different depths. The significance of the mean difference between the groups was examined by One Way Analysis of Variance, the significance of the difference between buccal and lingual surfaces at different depths within the groups by Dependent t-test (p

Prophylactic Effect of Theobromine on Pop Candies-induced enamel demineralization in human teeth

Prophylactic Effect of Theobromine on Pop Candies-induced enamel demineralization in human teeth

An in vitro evaluation of Icon resin infiltrant penetration into demineralized enamel lesions using an indirect staining technique with confocal laser scanning microscope analysis in dual fluorescence mode.

White spot lesion is the first clinical sign of a caries lesion and represents mineral loss from the enamel subsurface. The aim of this study was to evaluate the penetration depth (PD) of Icon resin infiltrant into artificially demineralized enamel lesions using confocal laser scanning microscope (CLSM) analysis in dual fluorescence mode. The design of the study was an in vitro study. 22 extracted human permanent maxillary central incisor teeth were collected, and enamel sections were obtained from the coronal middle third. All enamel specimens were exposed to demineralization and remineralization solutions for 14 days. On positive confirmation of enamel demineralization by scanning electron microscope analysis, 20 specimens were then subjected to Icon resin infiltration following manufacturer instructions. Specimens were processed with indirect staining technique using rhodamine B and sodium fluorescein dyes and examined under CLSM at ×10 magnification in dual fluorescence mode using ImageJ software to evaluate PD of resin infiltrant into demineralized enamel lesions. Obtained data were analyzed using an independent t-test. P ≤0.05 was considered statistically significant. The maximum depth of demineralized enamel lesion was 590 μm, and the mean depth was 290.78 ± 14.80 μm. The maximum depth of resin infiltrant penetration was 580 μm, and the mean depth was 279.08 ± 13.88 μm; P = 0.006. The percentage penetration of resin infiltrant was 95.99%. Icon resin infiltrant was highly effective in its depth of penetration into demineralized enamel lesions. The use of indirect staining and CLSM analysis in dual fluorescence mode is more reliable and accurate technique to evaluate the PD of resin infiltrant.

The use of mouthwash containing trimetaphosphate as an adjunct therapy to fluoridated toothpaste reduces enamel demineralization

IntroductionThe decline in dental caries has been attributed to the widespread use of fluoride (F). Two forms of presentation are fluoridated toothpaste (FT) and mouthwash (MW), widely used by the population. Materials and methodsThis study aimed to evaluate in vitro the effects of combining FT and MW, whether supplemented with sodium trimetaphosphate (TMP) or not, on dental enamel demineralization. Bovine enamel blocks (n = 60) were selected based on initial surface hardness (SHi) and divided into 5 experimental groups (n = 12 each): I) Placebo Toothpaste (without F/TMP); II) 1100 ppm F Toothpaste (FT); III) 1100F associated with a MW at 100 ppm F (FT + MW 100F); IV) 1100F associated with a MW at 225 ppm F (FT + MW 250F); and V) 1100F associated with a MW at 100 ppm F supplemented with 0.4 % TMP (FT + MW 100F-TMP). The blocks were treated twice a day, undergoing 5 pH cycles over 7 days. Thus, the percentage change in surface hardness (%SH), integrated subsurface hardness loss (ΔKHN), and the concentration of F, phosphorus (P), and calcium (Ca) in the enamel were determined. The data were submitted to ANOVA and Student-Newman-Keuls test (p < 0.001). ResultsThe 1100F group was statistically inferior to the groups associated with MW for %SH, ΔKHN, and the concentration of P and Ca in the enamel (p < 0.001). Blocks treated with FT + MW 225F and FT + MW 100F-TMP showed significantly lower %SH compared to the other groups (p < 0.001). The FT + MW 100F - TMP group exhibited the lowest depth mineral loss (ΔKHN), and higher concentration de P in enamel (p < 0.001). ConclusionThe adjunct use of MW with FT produces a greater protective effect in inhibiting enamel demineralization, and the supplementation of TMP to the MW with 100F provides a superior effect compared to MW with 225F. Clinical significanceThis combination of treatments could be regarded as one of several alternative fluoride supplements for subjects at elevated risk of caries.

Antimicrobial Effect of Dental Adhesive on Cariogenic Multi-Species Biofilm

Dental caries, or tooth decay, is one of the most widespread chronic and multifactorial diseases affecting people worldwide. It is described as the localized destruction of tooth structure by acids produced from bacteria fermentation of edible carbohydrates. The disease process begins within the bacterial biofilm on the surfaces of the teeth. Streptococcus sanguinis, Sreptococcusgordonii, and Streptococcus mutans are the main organisms in the biofilm associated with health or disease conditions in the oral cavity. Streptococcus mutans is believed to be the primary cause of enamel demineralization and the development of dental caries. S. gordonii and S. sanguinis belong to a group of streptococci considered health-related commensal oral bacteria, crucial for forming a biofilm on oral hard tissues. Several types of materials with multipurpose characteristics have been incorporated into dental adhesives. Recently, the calcium salt of an acidic monomer (calcium salt of 4-methacryloxyethyl trimellitic acid, or CMET) has been included in dental adhesive and demonstrated to suppress cariogenic biofilm formation of S. mutans. However, using a single-species model may not mimic the intricate antagonistic and synergistic relations that occur in oral biofilms. Therefore, the effect on cariogenic multi-species biofilm was assessed in this study. Dental adhesive consisting of CMET and 10-methacryloyloxydecyl dihydrogen calcium phosphate (MDCP) (Bio-Coat CA) was spread over the flat-bottom surface of the 96-well plate and LED light-cured. Then it was coated with sterile saliva at 37 °C for 45 min to form an acquired pellicle for microbial attachment. The multi-species bacterial suspension containing Streptococcus mutans ATCC 25715, Streptococcus sanguinis ATCC 10556, and Streptococcus gordonii ATCC 10558 was prepared and added to the saliva-coated well. Then, the plate was incubated at 37°C in a 5% CO2 atmosphere for 24 h, 48 h, and 72 h to support the biofilm formation. The number of vital bacteria in the biofilm was determined with the WST-8 Microbial Cell Counting Kit (Dojindo Molecular Technologies, USA). All tests were done in triplicate and repeated three times. For statistical analysis, Kruskal-Wallis and Dunn’s tests were employed. The results showed that at 24 h, 48 h, and 72 h, dental adhesive with CMET could inhibit the biofilm formation of multi-species bacteria significantly compared with controls. The percentages of biofilm inhibition were 29.1%, 34.7%, and 33.2% at 24 h, 48 h, and 72 h, respectively. Dental adhesive containing CMET displayed favorable multi-species biofilm-inhibiting effects up to 72 h of biofilm growth. It is a promising adhesive for use to prevent secondary caries at the sites of restorations.