Search Results (106)

Background/Objectives: Within the minimum intervention oral care (MIOC) delivery framework, the management and improvement in the esthetics of enamel white spot lesions (WSLs) are recommended. This study evaluated the chemomechanical and morphological characteristics of WSLs treated by four therapeutic approaches using Raman spectroscopy, Knoop microhardness (KH), and field-emission scanning electron microscopy (FESEM). Methods: Sixty human enamel slabs were divided into six groups: non-treated (baseline), WSLs (8% methylcellulose gel with 0.1 M lactic acid, pH 4.6 at 37 °C for 21 days), and four treated groups, namely bovine collagen supplement (Nutravita Ltd., Maidenhead, Berkshire, UK), Regenerate system (NR-5, Bordeaux, France), Sylc air abrasion (AquaCare, Denfotex Research Ltd., Edinburgh, UK), and CO₂ laser (JHC1180, Jinan, China). Treatment lasted 28 days, followed by four weeks of storage in artificial saliva (pH = 7.0, 37 °C). Bovine collagen was analyzed using Fourier-Transform Infrared Spectroscopy (FTIR). The mineral content, including the phosphate peak intensities (PO₄ ν₁, ν₂, and ν₄) and carbonate (CO₃), as well as tissue microhardness, were assessed at varying depths (50–200 µm), followed by morphological assessment. Results: The FTIR spectrum of bovine collagen powder confirms the presence of amide I, II, and III. It produced a statistically significant enhancement in the phosphate content and KHN compared to WSLs of up to 150 µm in depth (p < 0.001). Regenerate-treated surfaces recorded the highest phosphate content among groups at the superficial layer. All treatment interventions enhanced the morphology of lesions by covering the exposed prisms and inter-prismatic structure. Conclusions: Bovine collagen supplements can enhance the phosphate content and surface properties of enamel white spot lesions (WSLs) and could be considered a potential modality comparable to other micro-invasive approaches for addressing incipient enamel lesions. This could significantly impact dental care management. Full article

Although approximately half of global lithium consumption is used in the rechargeable battery industry, lithium is also in demand for other specialized applications, such as high-temperature lubricants, ceramics, glass, and pharmaceuticals. The growing need for efficient lithium recovery and recycling underscores the importance of fast and accurate analytical tools for determining lithium concentrations in non-compliant and waste materials generated by industrial processes. In this paper, we present a machine learning-based procedure utilizing Laser-Induced Breakdown Spectroscopy (LIBS) to accurately quantify lithium concentrations in lithium-rich non-compliant materials derived from the industrial production of enamels used for coating metallic surfaces. This procedure addresses challenges such as strong self-absorption and matrix effects, which limit the effectiveness of conventional univariate calibration methods. By employing a multivariate approach, we developed a single model capable of quantifying lithium content across a wide concentration range. A comparison of the LIBS results with those obtained using conventional laboratory analysis (Inductively Coupled Plasma–Optical Emission Spectrometry, ICP-OES) confirms that LIBS can deliver the speed, precision, and reliability required for potential routine applications in the lithium recovery and recycling industry. Full article

Background: Dental caries is a prevalent dental problem affecting primary and permanent teeth. Early demineralization of enamel lesions can be reversed through remineralization. Many studies have focused on caries prevention and disease progression arrest using silver diamine fluoride (SDF). No in vitro studies have compared the remineralization effects of different 38% SDF solutions on artificially demineralized enamel lesions. This study aimed to compare the remineralization potential of three commercial 38% silver diamine fluoride formulations on artificial enamel lesions in primary teeth using a pH cycling model. The hypothesis was as follows: different commercial SDF formulations would exhibit varying remineralization effects, as measured by surface microhardness, due to potential differences in their compositions. Materials and Methods: In this study, 75 primary molars were randomized into five groups (N = 15): I: baseline, II: SDF Riva Star Aqua^® 38%, III: Riva Star^® 38%, IV: SDF Advantage Arrest^® 38%, and V: control. Artificial caries were created by submerging teeth in 10 mL of demineralization solution (pH 4.5) for three days in a light-resistant container, ensuring distinct visual changes in the enamel as per the International Caries Detection and Assessment System (ICDAS level 2). After pH cycling, all samples underwent a standardized Vickers microhardness test (VMHT) with a 50 g load for 15 s. Data were analyzed using one-way ANOVA and Tukey’s post hoc test, with a significance level set at p ≤ 0.05. Results: The one-way ANOVA test indicated a significant difference in microhardness among the groups (SDF Riva Star Aqua, SDF Riva Star, and SDF Advantage Arrest), with an F-value of 167.73 and p < 0.001. The post hoc Scheffé test showed that SDF Riva Star Aqua and SDF Riva Star were not significantly different (p = 0.388). However, SDF Advantage Arrest had a significantly higher mean microhardness compared to both groups (p < 0.001). Overall, these results show that SDF Advantage Arrest leads to greater microhardness than SDF Riva Star Aqua or SDF Riva Star. Conclusions: SDF Advantage Arrest showed superior performance among the SDF-treated groups, significantly increasing microhardness compared to SDF Riva Star Aqua and SDF Riva Star. This suggests that SDF Advantage Arrest offers enhanced remineralization and structural strengthening, making it the most effective option for managing demineralized primary teeth. Future research should investigate the long-term performance and mechanisms of these treatments to optimize clinical protocols for preserving primary tooth integrity. Full article

Background/Objectives: It is unclear whether enamel margins should be beveled in direct resin-based restorations. This study evaluated the influence of enamel beveling on the marginal quality of mesio-occluso-distal (mod) cavity boxes. Methods: Seventy-five caries-free human molars were divided into three groups. Mod-cavities with the entire margin in the enamel were prepared ± proximal bevel (n = 25). Twenty-five beveled mod-cavities served as control. Each group was restored with five material combinations: micro hybrid composite with etch-and-rinse (ER) or self-etch (SE) adhesive, compomer with ER or SE, and low-shrinkage composite with ER. A complex filling technique was used in the control. After artificial aging (1000 thermal cycles, 5/55 °C), the percentage of continuous margins (PCM) of the proximal boxes was analyzed by scanning electron microscopy using epoxy replicas (×300), and the marginal seal was assessed by light microscopy after dye penetration (×64). Statistical analysis was performed using Kruskal–Wallis and Mann–Whitney U tests (p < 0.05). Results: No significant differences in PCM were found between the restorative systems (p = 0.075). The composite with low shrinkage showed the highest mean PCM of all groups (78.1%). Significant differences in marginal seal were observed between the restoratives after bevel preparation (p < 0.05). Beveling significantly improved the PCM only for the hybrid composite (p < 0.05), whereby the effect on marginal seal was less pronounced. Conclusions: Clinicians should be aware that beveling mod-cavities does not necessarily improve the marginal quality of direct resin-based restorations bonded with well-established adhesives and may be more beneficial for traditional hybrid composites. Full article

Background: Dental enamel demineralization is a critical early event in the development of dental caries. To address this, bioactive compounds have been explored for their potential to mitigate enamel demineralization and promote remineralization. Previous studies have demonstrated that varnishes containing natural compounds such as trans,trans-farnesol (tt-farnesol), quercetin, and theobromine exhibit antimicrobial activity, suggesting potential in caries prevention. Thus, this laboratory study assessed the ability of these varnishes to prevent enamel caries lesion formation by using a chemical model to determine whether these natural compounds interfered with de- and remineralization processes in the absence of a cariogenic biofilm. Methods: Sixty bovine enamel specimens, each measuring 5 × 5 × 2 mm, were selected according to their initial surface hardness (SHI), measured by Knoop hardness in three indentations spaced 100 µm apart. The specimens were allocated to the following groups in a random manner (n = 15): an experimental varnish without compounds (NC/negative control); experimental varnishes containing the combination of tt-farnesol, quercetin, and theobromine at concentrations of 1.5% (E1) and 4.5% (E2); and Duraphat™ (NaF 5%/gold standard—D). After applying the varnishes, they remained in artificial saliva for 6 h. The specimens were then subjected to 8 pH cycles, including 4 h of demineralization and 20 h of remineralization. Surface hardness was measured again to calculate the percentage of surface hardness loss (%SHL), and three specimens from each group were examined using scanning electron microscopy. Comparisons were made using ANOVA (p < 0.05). Results: The D group (5% NaF) demonstrated a significantly lower %SHL (75.5% ± 7.88) than the other groups (p < 0.05). E1 (86.3% ± 5.33) was statistically similar to NC (81.8% ± 4) but lower than E2. E2 showed the highest %SHL (91.6% ± 3.64) compared to the other groups. Surface demineralization was evident in all specimens post pH cycling. Conclusion: The bioactive varnishes containing tt-farnesol, quercetin, and theobromine at concentrations of 1.5% and 4.5% did not exhibit a protective effect against mineral loss in dental enamel in the absence of a cariogenic biofilm. Full article

Amorphous calcium phosphate (ACP) is a well-established bioceramic material known to promote the remineralization of dental hard tissues. White spot lesions (WSLs) represent the initial stage of enamel demineralization and are frequently observed in patients with fixed orthodontic appliances or inadequate oral hygiene. Although recommendations for remineralizing agents include both the prevention of lesion progression and the stimulation of tissue remineralization, the clinical efficacy of ACP-based materials remains under debate. This systematic review, registered in the PROSPERO database (CRD42024540595), aims to evaluate the clinical efficacy of casein phosphopeptide-amorphous calcium phosphate (CPP-ACP)-based products in the remineralization of WSLs and to compare these outcomes with those achieved using non-bioceramic approaches. Inclusion criteria comprised randomized clinical trials, prospective cohort studies, and pilot studies conducted on human subjects with WSLs affecting permanent teeth. Studies involving artificial WSLs or non-cariogenic enamel lesions were excluded. The quality of the included studies was assessed using the Cochrane Risk of Bias 2 (RoB 2) tool. Fourteen articles met the inclusion criteria and were analyzed. The main findings indicate that CPP-ACP is clinically effective in promoting the remineralization of WSLs, although the results were inconsistent across studies. Comparisons with placebo and resin infiltration treatments revealed greater efficacy for CPP-ACP. The combination of CPP-ACP with fluoride appeared to further enhance the remineralizing effect on WSLs. Additional standardized clinical studies with longer follow-up periods are warranted to confirm these outcomes. Full article

Background: Early caries management is essential to enable reversal of white spot lesions without the further need for operative interventions, especially in primary dentition. Silver-based compounds can be quite effective in arresting caries lesions; however, a major drawback is teeth staining. This study aimed to evaluate the remineralization potential and aesthetic effects of novel, green-synthesized nano-silver fluoride (NSF) on artificial white spot lesions in primary teeth in comparison to 38% silver diamine fluoride (SDF) and silver diamine fluoride/potassium iodide (SDF/KI). Materials and Methods: NSF was synthesized using green tea extract. Sixty primary teeth specimens with artificial enamel lesions were randomly divided into five groups depending on the applied material: 38% SDF, 38% SDF/KI, single and double application of NSF, and control group. Treatments were followed by pH cycling. Surface microhardness and photographic analysis were conducted to assess remineralization and staining. Statistical analysis was conducted using non-parametric tests including Kruskal–Wallis and Mann–Whitney U tests with Bonferroni correction. Results: The greatest increase in microhardness was observed in the group receiving double NSF application. Its remineralizing potential was comparable to that of 38% SDF/KI, with no statistically significant difference (p = 1.000). Importantly, NSF-treated samples exhibited no teeth discoloration, unlike the black staining observed in SDF and SDF/KI groups. Conclusions: Green-synthesized NSF is a promising alternative to conventional SDF and SDF/KI, offering remineralization benefits without compromising aesthetics. The eco-friendly formulation and non-staining properties support its potential for clinical use in pediatric dentistry. Full article

Dens invaginatus is a developmental dental anomaly characterized by the infolding of the enamel organ into the dental papilla during early odontogenesis. This process leads to a broad spectrum of anatomical variations, ranging from minor enamel-lined pits confined to the crown to deep invaginations extending through the root, occasionally communicating with periodontal or periapical tissues. The internal complexity of affected teeth presents diagnostic and therapeutic challenges, particularly in severe forms that mimic root canal systems or are associated with pulpal or periapical pathology. Maxillary lateral incisors are most frequently affected, likely due to their unique developmental timeline and morphological susceptibility. Although various classification systems have been proposed, Oehlers’ classification remains the most clinically relevant due to its simplicity and correlation with treatment complexity. Recent advances in diagnostic imaging, especially cone beam computed tomography (CBCT), have revolutionized the identification and classification of these anomalies. CBCT-based adaptations of Oehlers’ classification allow for the precise assessment of invagination extent and pulpal involvement, facilitating improved treatment planning. Contemporary therapeutic strategies now include calcium-silicate-based cement sealing materials, endodontic microsurgery for inaccessible anatomy, and regenerative endodontic procedures for immature teeth with necrotic pulps. Emerging developments in artificial intelligence, genetic research, and tissue engineering promise to further refine diagnostic capabilities and treatment options. Early detection remains critical to prevent complications such as pulpal necrosis or apical disease. A multidisciplinary, image-guided, and patient-centered approach is essential for optimizing clinical outcomes in cases of dens invaginatus. Full article

Objective: This study evaluated the efficacy of a novel interproximal fluoride delivery device, Cav-Aid^®, in remineralizing initial proximal caries, comparing it with conventional fluoride treatments. Methods: Initial caries lesions were produced on bovine enamel blocks by subjecting the blocks to a 3-day demineralization process by plaque growth in a mixed-species microbial caries model. After demineralization, the baseline surface microhardness (SMHb) was measured. The blocks were embedded into cavities prepared on the proximal surfaces of extracted human teeth to simulate natural interproximal contacts. The teeth were randomly assigned to six treatment groups (20/group): artificial saliva (AS), Cav-Aid^® only (CA), Cav-Aid^®/fluoride toothpaste (CA+F), fluoride varnish applied via flossing (FV-Floss), fluoride varnish applied via painting on the interdental cleavage (FV-Paint), and daily fluoride mouthrinse (F-Mouthrinse). The samples then underwent a 14-day pH cycling protocol to simulate remineralization conditions. The post-treatment SMH (SMHr) was measured. Statistical analysis comprised paired t-tests and ANOVA/Tukey’s post hoc comparisons (p < 0.05). Results: All fluoride-treated groups exhibited significant increases in SMHr compared with SMHb (p < 0.001). CA+F group showed the highest percentage remineralization (27.39%), followed by CA (22.16%), then the FV and mouthrinse groups (9.25–11.80%). The AS group exhibited the lowest remineralization (4.89%). CA+F demonstrated significantly greater remineralization than FV or mouthrinse (p < 0.05). However, there was no significant difference between CA alone and CA+F. Also, there was no significant difference between CA alone and FV-Floss or FV-Paint (p > 0.05). Conclusions: Within the limit of the present study, the Cav-Aid^® targeted fluoride delivery system demonstrated greater efficacy than FV alone in interproximal remineralization. Dual-modality fluoride treatments (CA+F) provided the greatest remineralization benefits, highlighting the importance of sustained fluoride exposure. Full article

Objectives: This study aimed to compare in vitro the protective effect of two enamel remineralizing agents, a varnish containing β-tricalcium phosphate with sodium fluoride (β-TCP-F) and a paste containing casein phosphopeptide-amorphous calcium phosphate with sodium fluoride (CPP-ACP-F), on artificially demineralized human enamel. Methods: A total of 120 human third molar enamel specimens were randomly assigned to four groups (n = 30 each): Group I (healthy enamel, control), Group II (initially demineralized, lesioned enamel), Group III (demineralized enamel and treated with β-TCP-F), and Group IV (demineralized enamel and treated with CPP-ACP-F). Groups II–IV underwent, for 15 days, a daily pH cycling regimen consisting of 21 h of demineralization under pH 4.4, followed by 3 h of remineralization under pH 7. Groups III and IV were treated with either β-TCP-F or CPP-ACP-F, prior to each 24 h demineralization–remineralization cycle. Fluoride ion release was measured after each pH cycle. Surface hardness, roughness, wettability, and Streptococcus mutans biofilm formation were assessed on days 5, 10, and 15 after a daily pH cycle. Results: CPP-ACP-F treatment showed a larger improvement in surface hardness (515.2 ± 10.7) compared to β-TCP-F (473.6 ± 12.8). Surface roughness decreased for both treatments compared to initially lesioned enamel; however, the decrease in roughness in the β-TCP-F group only reached a value of 1.193 μm after 15 days of treatment, a significantly larger value in comparison to healthy enamel. On the other hand, the decrease in roughness in the CPP-ACP-F treatment group reached a value of 0.76 μm, similar to that of healthy enamel. Contact angle measurements indicated that wettability increased in both treatment groups (β-TCP-F: 71.01°, CPP-ACP-F: 65.24°) compared to initially lesioned samples in Group II, reaching WCA values similar to or smaller than those of healthy enamel surfaces. Conclusions: Both treatments, β-TCP-F and CPP-ACP-F, demonstrated protective effects against enamel demineralization, with CPP-ACP-F showing superior enhancement of surface hardness and smoother enamel texture under in vitro pH cycling conditions. β-TCP-F varnish and CPP-ACP-F paste treatments counteracted surface modifications produced on human healthy enamel by in vitro demineralization. Full article

Background and Objectives: Contemporary caries treatment seeks to preserve hard dental tissues as well as to promote lesion remineralization and biological tissue regeneration. While fluoride-based treatments remain the gold standard, their effectiveness has limitations, prompting interest in innovative remineralization technologies. Nano-hydroxyapatite (nano-HA) varnish and self-assembling peptide (SAP) P11-4 are promising biomimetic materials that promote enamel repair, yet long-term data on their efficacy are limited. The objectives of this study were to evaluate the effectiveness of nano-HA varnish and peptide P11-4 in restoring enamel surface hardness after artificial lesions in vitro and to compare them to a control group and fluoride varnish. Materials and Methods: Artificial enamel lesions were created on the buccal surfaces of 36 extracted human molars, which were randomly divided into four groups (n = 9): control, peptide P11-4, fluoride varnish, and nano-hydroxyapatite varnish. After applying the materials as per manufacturer instructions, specimens were stored in artificial saliva for 14 days. Enamel surface hardness was measured using the Vickers hardness test (HV) at baseline, after demineralization, and after remineralization. Statistical analysis was performed with “IBM SPSS 27.0” using non-parametric Kolmogorov–Smirnov, Kruskal–Wallis, Dunn’s, and Wilcoxon tests. Results: The mean baseline enamel hardness value was 323.95 (SD 33.47) HV. After 14 days of demineralization, the mean surface hardness of artificial enamel lesions significantly plummeted to 172.17 (SD 35.96) HV (p = 0.000). After 14 days of remineralization, the mean value significantly increased to 213.21 (SD 50.58) HV (p = 0.001). The results of the study revealed statistically significant enamel remineralization of the peptide P11-4 group in regard to the demineralized enamel (p < 0.05). In contrast, there were no significant results in other treatment groups (p > 0.05). Remineralization of enamel was the highest in samples from the P11-4 group (54.1%), followed by the nano-HA group (35.4%), FV group (17.8%), and control group (11.2%). There was a significant difference (p < 0.05) in the remineralizing ability between the peptide P11-4 and all other treatment groups. Conclusions: Self-assembling peptide P11-4 effectively remineralized artificial enamel lesions and proved to be significantly more effective compared to fluoride varnish and nano-hydroxyapatite varnish, showcasing its superior performance as a remineralizing agent. Full article

Peptide-based biomimetic treatments have gained increased attention in the dental field due to their biocompatibility and minimally invasive qualities. These biomimetic approaches can replicate the native architecture of dental tissues, thus contributing to higher success rates and improved longevity of restorations. The aim of this study was first to examine the biocompatibility and stability of an amelogenin peptide-based chitosan hydrogel (P26-CS) against salivary enzymes. Second, we aimed to evaluate its efficacy in biomimetically repairing human dental lesions in situ. White spot lesions (WSLs) in enamel and non-carious cervical lesions (NCCLs) in dentin were artificially created. Chitosan (CS) improved peptide stability, while remineralization of enamel sections with P26-CS was not impeded by salivary enzymes. The peptide was not cytotoxic, irritating, or sensitizing. Fluorescently labeled P26-CS penetrated ~300 μm into the enamel of WSLs and ~100 μm into the dentin of NCCLs. After peptide treatment, quantitative light-induced fluorescence (QLF) and microcomputed tomography (μCT) indicated a gain in mineral density of WSLs. In NCCLs, scanning electron microscopy showed that the dentin was covered by a mineral layer of needle-shaped crystals. Our results show that the repair of artificial WSLs and NCCLs was achieved by P26 peptide-guided remineralization and demonstrate its potential to repair dental lesions. Full article

Outdoor stone relics, including inscriptions, statues, temple grottoes, etc., are continuously subjected to natural weathering and air pollutants. Those made of marbles and other carbonate rocks are particularly vulnerable to acid rains, which can be protected by acid-resistant coatings. A novel method to prepare enamel-like hydroxyapatite coating on marble surfaces is presented in this paper and analyzed using optical microscopy, a scanning electronic microscope, grazing incident X-ray diffraction, and nano-indentation. The described coating is composed of tightly arranged hydroxyapatite nanorods, perpendicular to the marble substrate, with a thickness of 3–5 μm. Not only does the coating exhibit high acid resistance, it also has considerably higher elastic modulus and hardness compared to that synthesized by the well-known diammonium phosphate (DAP) method owing to the wellarranged microstructure. Consequently, the enamel-like hydroxyapatite coating would probably be more effective and durable for marble protection than the existing calcium phosphate coating. Full article

This study aimed to evaluate the ability of fluoride-releasing restorative materials to remineralize artificially demineralized proximal enamel adjacent to class II restorations. Fifty-four demineralized enamel lesions were created on extracted premolar teeth, and the baseline lesion depth (LD) and mineral density (MD) were measured using micro-CT. The samples were randomly assigned to one of four groups, each in contact with a class II restorative material: Filtek Z350 XT™ (FZ), Cention N^® (CN), Fuji II LC^® (FJ), or Equia Forte^® (EQ). Finally, post 14 days of pH cycling, measurements were taken. SEM, EDX, and Raman Imaging Microscopy were additionally performed. The results showed significant reductions in LD for all fluoride-releasing materials (CN, FJ, EQ). EQ and CN showed a significantly higher percentage change in LD than FZ. The MD of adjacent demineralized enamel increased significantly in all groups. There was no significant difference in the percentage change in MD between groups. SEM-EDX images revealed greater mineral deposition in fluoride-releasing materials than FZ. The Ca/P ratio of demineralized enamel adjacent to CN was equal to that of EQ, while FJ demonstrated the highest ratio. In conclusion, fluoride-releasing materials exhibited a reduction in the LD of adjacent demineralized enamel and demonstrated Ca/P ratios higher than FZ. CN may be an alternative restorative material to remineralize adjacent demineralized enamel. Full article

This study aimed to evaluate the micro-nanostructure and color changes of dental enamel after treatment with new gel formulations containing papain or bromelain. Eighty caries-free, extracted human teeth were randomly divided into two groups (n = 40) and stained by immersion in either coffee or Tedi juice for 4 h daily over five consecutive days. After staining, the samples were washed and stored in artificial saliva at 37 °C. The stained samples were then treated with four different whitening gels (GC, G1, G2, and Opalescence 15%) for 4 h daily. Following each treatment, the samples were rinsed and stored in artificial saliva. Color changes were measured using a digital spectrophotometer to assess CIEL*a*b* ΔE* and the Whiteness index (WI). The enamel micro-nanostructure was analyzed using SEM and AFM. Data were statistically analyzed using one-way ANOVA followed by Tukey’s HSD test. The results showed that gels containing papain and bromelain were more effective than the commercial gel in removing stains. SEM and AFM analysis indicated that papain was particularly effective for removing coffee stains, while bromelain was better for stains from natural juices. Healthy enamel has a Ra value of approximately 10 nm, which increases to about 40 nm after staining. Papain restored enamel roughness to approximately 8 nm for coffee stains and bromelain restored it to 11 nm for juice stains, delivering optimal results, while commercial gel ensures a roughness of about 15 nm after stain removal. CIELAB reveals notable changes in ΔE and WI after bleaching, revealing that papain gel is optimal for coffee stain removal and bromelain gel is optimal for natural juice stains. In conclusion, dental stains should be assessed by a dentist to determine the most suitable gel for achieving optimal results. Full article