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Acidic beverages are believed to elevate the risk of enamel surface erosion. In addition to the intake of soft drinks, the increased consumption of salad dressings has been linked to a higher prevalence of dental erosion. Therefore, the current study aimed to investigate the influence of bottled salad dressings on the development of enamel erosion in the presence or absence of pellicle through in vitro experiment. Preliminary pH and calcium analyses of solutions were performed. Highest pH and calcium content was found for sandwich spread i.e., 4.69 and 55.4 mg/100 g grams, respectively. Eighty tooth specimens (measuring 4 × 4 × 3 mm) were prepared from extracted human premolars and randomly assigned to four groups (group 1: orange juice; group 2: eggless plain mayonnaise; group 3: sandwich spread; and group 4: thousand island dressing) with 20 samples in each group. Ten tooth specimens from each group were immersed in 20 ml of the respective solutions for 5 min (control group). The remaining ten tooth specimens from each group were submerged in 5 mL saliva vials for 3 min to facilitate salivary pellicle formation before being immersed in their respective solutions for 5 min (saliva-covered group). Pre and post-experimental assessments of enamel roughness and hardness were conducted using a surface roughness tester and Knoop Hardness indenter, respectively. Overall, enamel roughness was notably elevated in the control group, with the eggless plain mayonnaise (0.52 ± 0.38) and thousand island dressing groups (0.57 ± 0.29) showing a significant increase in surface roughness post-test (p = 0.05). Nevertheless, there was no significant difference in the enamel roughness between the groups. On the other hand, regardless of the presence/absence of the salivary pellicle, a marked decrease in enamel hardness was observed among all groups except for group 3 (sandwich spread) with a mean score of 311.5 ± 82.6 (p < 0.05). A significant increase in surface roughness and reduction in enamel hardness was observed with salad dressings. However, in vitro formed salivary pellicle showed a protective effect against tooth erosion. [Display omitted] [ABSTRACT FROM AUTHOR]

Abstract Objectives This study aimed to assess the effect of proanthocyanidin, palm oil and vitamin E against erosive and erosive+abrasive challenges in vitro after enamel pellicle formation in situ. Methodology Bovine enamel blocks (n=84) were obtained and divided into the following treatment groups: negative control (NC) - deionized water; positive control (PC) - SnCl2/NaF/AmF-containing solution; palm oil (PO); 2% proanthocyanidin (P2); vitamin E (VitE); 2% proanthocyanidin+palm oil (P2PO); and 2% proanthocyanidin+vitamin E (P2VitE). For 5 days, one half of the sample from each group was subjected to erosion and the other half was subjected to erosion+abrasion. The acquired enamel pellicle (AEP) was pre-formed in situ for 30 minutes. The specimens were then treated in vitro with solutions (500 µl, 30s for each group). Subsequently, the blocks were left in the oral cavity for another hour to obtain the modified AEP. The blocks were immersed in 0.5% citric acid (pH=2.5) for 90s, 4×/day. AEP formation and treatment were carried out before the first and third erosive challenges, and after these challenges, abrasive cycles (15s) were performed on half of the samples. Enamel wear was quantified by profilometry and data were analyzed by two-way ANOVA and Tukey’s test (p

(1) Background: In the oral environment, sound enamel and dental restorative materials are immediately covered by a pellicle layer, which enables bacteria to attach. For the development of new materials with repellent surface functions, information on the formation and maturation of salivary pellicles is crucial. Therefore, the present in situ study aimed to investigate the proteomic profile of salivary pellicles formed on different dental composites. (2) Methods: Light-cured composite and bovine enamel samples (controls) were exposed to the oral cavity for 30, 90, and 120 min. All samples were subjected to optical and mechanical profilometry, as well as SEM surface evaluation. Acquired pellicles and unstimulated whole saliva samples were analyzed by SELDI–TOF–MS. The significance was determined by the generalized estimation equation and the post-hoc bonferroni adjustment. (3) Results: SEM revealed the formation of homogeneous pellicles on all test and control surfaces. Profilometry showed that composite surfaces tend to be of higher roughness compared to enamel. SELDI–TOF–MS detected up to 102 different proteins in the saliva samples and up to 46 proteins in the pellicle. Significant differences among 14 pellicle proteins were found between the composite materials and the controls. (4) Conclusions: Pellicle formation was material- and time-dependent. Proteins differed among the composites and to the control. [ABSTRACT FROM AUTHOR]

BackgroundThe dental pellicle is a thin layer of up to several hundred nm in thickness, covering the tooth surface. It is known to protect the teeth from acid attacks through its selective permeability and it is involved in the remineralization process of the teeth. It functions also as binding site and source of nutrients for bacteria and conditioning biofilm (foundation) for dental plaque formation.MethodsFor this updated literature review, the PubMed database was searched for the dental pellicle and its composition.ResultsThe dental pellicle has been analyzed in the past years with various state-of-the art analytic techniques such as high-resolution microscopic techniques (e.g., scanning electron microscopy, atomic force microscopy), spectrophotometry, mass spectrometry, affinity chromatography, enzyme-linked immunosorbent assays (ELISA), and blotting-techniques (e.g., western blot). It consists of several different amino acids, proteins, and proteolytic protein fragments. Some studies also investigated other compounds of the pellicle, mainly fatty acids, and carbohydrates.ConclusionsThe dental pellicle is composed mainly of different proteins, but also fatty acids, and carbohydrates. Analysis with state-of-the-art analytical techniques have uncovered mainly acidic proline-rich proteins, amylase, cystatin, immunoglobulins, lysozyme, and mucins as main proteins of the dental pellicle. The pellicle has protective properties for the teeth. Further research is necessary to gain more knowledge about the role of the pellicle in the tooth remineralization process.

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.

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.

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 calciumbinding 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. [ABSTRACT FROM AUTHOR]

(1) Background: In the oral environment, sound enamel and dental restorative materials are immediately covered by a pellicle layer, which enables bacteria to attach. For the development of new materials with repellent surface functions, information on the formation and maturation of salivary pellicles is crucial. Therefore, the present in situ study aimed to investigate the proteomic profile of salivary pellicles formed on different dental composites. (2) Methods: Light-cured composite and bovine enamel samples (controls) were exposed to the oral cavity for 30, 90, and 120 min. All samples were subjected to optical and mechanical profilometry, as well as SEM surface evaluation. Acquired pellicles and unstimulated whole saliva samples were analyzed by SELDI–TOF–MS. The significance was determined by the generalized estimation equation and the post-hoc bonferroni adjustment. (3) Results: SEM revealed the formation of homogeneous pellicles on all test and control surfaces. Profilometry showed that composite surfaces tend to be of higher roughness compared to enamel. SELDI–TOF–MS detected up to 102 different proteins in the saliva samples and up to 46 proteins in the pellicle. Significant differences among 14 pellicle proteins were found between the composite materials and the controls. (4) Conclusions: Pellicle formation was material- and time-dependent. Proteins differed among the composites and to the control.

Introduction and Aims: With the increasing prevalence of dentin hypersensitivity, more and more desensitizing agents with tubule-occluding properties are advocated in the market. The aim of the present study was to investigate the deposition of these agents on the dentin surface under in-situ conditions., Methods: Bovine dentin specimens were pretreated with phosphoric acid and fixed to individual upper splints that were carried by up to 2 subjects for 3 min to allow pellicle formation. The desensitizing agents containing either calcium carbonate and arginine, casein-phosphopeptide amorphous calcium phosphate, zinc-carbonate hydroxyapatite, tetracalcium phosphate and dicalcium phosphate anhydrous or hydroxyapatite nanoparticles were applied ex situ. Specimens without treatment served as controls. After a further 6 h of intraoral exposure, specimens were removed and analysed by scanning (n = 4 specimens per substance, in total) and transmission electron microscopy (n = 2 specimens per substance)., Results: Application of desensitizing agents resulted in the deposition of different structures on the dentin surface and occlusion of dentinal tubules., Conclusion: The ultrastructural analysis using transmission electron microscopy indicates that dentinal tubules were occluded under in-situ conditions not only by inorganic but also by organic deposits from the oral cavity., Competing Interests: Conflict of interest None disclosed., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Objectives: Previous studies on short- and long-term pellicles showed that the enamel pellicle provides partial protection against erosion. The aim of the present study was to investigate the protective properties of clinically relevant pellicles formed within 2 to 24 h. The hypothesis was that factors such as pellicle formation time, intraoral location, and acidic challenge severity would not influence the erosion-protective properties of the pellicle., Methods: Six subjects participated in the study. Bovine enamel specimens were prepared and intraorally exposed at buccal or palatal sites for 2, 6, 12, and 24 h to allow pellicle formation, followed by erosion using 0.1 % or 1 % citric acid. Calcium release and surface microhardness were measured, and specimens were analysed using scanning and transmission electron microscopy. Quantitative data were statistically analysed with three-way ANOVA and Tuckey's multiple comparison test (p = 0.05)., Results: Pellicle formation time and intraoral location did not significantly influence the erosion-protective properties of the pellicle, while citric acid concentration significantly affected enamel erosion. The pellicle thickness increased with longer formation times and on buccal sites, but decreased or was entirely removed following treatment with 0.1 % or 1 % citric acid, respectively. The enamel surface exhibited a characteristic erosion pattern., Conclusions: This study underscores the importance of investigating pellicle properties within the critical 2- to 24-h timeframe and highlights the significance of pellicle thickness in acid resistance., Clinical Significance: These findings provide valuable insights into the factors influencing the protective properties of enamel pellicles and could guide preventive measures in dental practice., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Biomaterials, once inserted in the oral cavity, become immediately covered by a layer of adsorbed proteins that consists mostly of salivary proteins but also of plasma proteins if the biomaterial is placed close to the gingival margin or if it becomes implanted into tissue and bone. It is often this protein layer, rather than the pristine biomaterial surface, that is subsequently encountered by colonizing bacteria or attaching tissue cells. Thus, to study this important initial protein adsorption from human saliva and serum and how it might be influenced through chemical modification of the biomaterial surface, we have measured the amount of protein adsorbed and analyzed the composition of the adsorbed protein layer using gel electrophoresis and western blotting. Here, we have developed an in vitro model system based on silica surfaces, chemically modified with 7 silane-based self-assembled monolayers that span a broad range of physicochemical properties, from hydrophilic to hydrophobic surfaces (water contact angles from 15° to 115°), low to high surface free energy (12 to 57 mN/m), and negative to positive surface charge (zeta potentials from –120 to +40 mV at physiologic pH). We found that the chemical surface functionalities exerted a substantial effect on the total amounts of proteins adsorbed; however, no linear correlation of the adsorbed amounts with the physicochemical surface parameters was observed. Only the adsorption behavior of a few singular protein components, from which physicochemical data are available, seems to follow physicochemical expectations. Examples are albumin in serum and lysozyme in saliva; in both, adsorption was favored on countercharged surfaces. We conclude from these findings that in complex biofluids such as saliva and serum, adsorption behavior is dominated by the overall protein-binding capacity of the surface rather than by specific physicochemical interactions of single protein entities with the surface. [ABSTRACT FROM AUTHOR]

Surfactants are important components of oral care products. Sodium dodecyl sulfate (SDS) is the most common because of its foaming properties, taste and low cost. However, the use of ionic surfactants, especially SDS, is related to several oral mucosa conditions. Thus, there is a high interest in using non-ionic and amphoteric surfactants as they are less irritant. To better understand the performance of these surfactants in oral care products, we investigated their interaction with salivary pellicles i.e., the proteinaceous films that cover surfaces exposed to saliva. Specifically, we focused on pentaethylene glycol monododecyl ether (C12E5) and cocamidopropyl betaine (CAPB) as model nonionic and amphoteric surfactants respectively, and investigated their interaction with reconstituted salivary pellicles with various surface techniques: Quartz Crystal Microbalance with Dissipation, Ellipsometry, Force Spectroscopy and Neutron Reflectometry. Both C12E5 and CAPB were gentler on pellicles than SDS, removing a lower amount. However, their interaction with pellicles differed. Our work indicates that CAPB would mainly interact with the mucin components of pellicles, leading to collapse and dehydration. In contrast, exposure to C12E5 had a minimal effect on the pellicles, mainly resulting in the replacement/solubilisation of some of the components anchoring pellicles to their substrate. [ABSTRACT FROM AUTHOR]

The aim of this study was to compare the acquired enamel pellicle protein profile of professional wine tasters with mild and moderate erosive tooth wear. Twelve professional wine tasters participated (3 from a low tooth wear group; 9 from a high tooth wear group). Acquired enamel pellicle samples were collected and processed for proteomic analysis (nLC‐ESI‐MS/MS). The acquired enamel pellicle proteomic profile was different between the groups. The proteins found exclusively in the low tooth wear group were histatins 1 and 3 and mucins 7 and 21. When comparing the wear groups, proteins with higher levels in the low tooth wear group included neutrophil defensins (1 and 3), lysozyme C, lysozyme, myeloperoxidase, and squalene monooxygenase. In conclusion, the findings indicate that the proteins found at higher levels in the low tooth wear group and proteins exclusively found in the low tooth wear group might be protective and, therefore, could be good candidates for further studies regarding their potential to be added to dental products to protect professional wine tasters from extrinsic erosive tooth wear. [ABSTRACT FROM AUTHOR]

Objective: This study evaluated the effect of administration of trans-resveratrol-containing orodispersible tablets on the protein composition of the AEP and on blood plasma trans-resveratrol concentrations., Methods: Ten volunteers participated in two crossover double-blind phases. In each phase, after dental prophylaxis, they received a trans-resveratrol (15 mg) orodispersible tablet, or a placebo tablet (without actives). The AEP formed after 120 min was collected with electrode filter papers soaked in 3 % citric acid. Blood samples were collected 30, 45, 60 and 120 min after the use of the tablet. After protein extraction, AEP samples were analyzed by shotgun labelfree quantitative proteomics and plasma samples were analyzed by high-performance liquid chromatography (HPLC)., Results: Eight hundred and two proteins were identified in the AEP. Among them, 336 and 213 were unique to the trans-resveratrol and control groups, respectively, while 253 were common to both groups. Proteins with important functions in the AEP had increased expression in the trans-resveratroltreated group, such as neutrophil defensins, S100 protein isoforms, lysozyme C, cystatin-D, mucin-7, alphaamylase, albumin, haptoglobin and statherin. Trans-resveratrol was detected in the plasma at all the times evaluated, with the peak at 30 min., Conclusions: The administration of trans-resveratrol in sublingual orodispersible tablets was effective both to increase the bioavailability of the polyphenol and the expression of antibacterial and acid-resistant proteins in the AEP, which might benefit oral and general health., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Ltd.)

Objective: The aim of this study was to determine the effect of different concentrations of resveratrol in protecting enamel against initial dental erosion in vitro., Methods: Ninety bovine enamel samples (4 × 4 mm) were divided into six groups: Phosphate buffered saline (negative control; PBS), Commercial solution (Elmex Erosion Protection™; positive control) and resveratrol at 4 different concentrations (1, 10, 100 or 400 µg/mL). Initially, the samples were incubated in saliva for the formation of the acquired pellicle (250 µL, 1 h, 37 °C, 250 rpm). Afterward, the samples were incubated in the respective treatments (250 µL, 1 min, 37 °C, 250 rpm) and then reincubated in saliva (250 µL, 1 h, 37 °C, 250 rpm). Finally, the samples were subjected to an erosive challenge by incubating in 1 % citric acid (1 mL, pH 3.5, 1 min, 25 °C, 250 rpm). The percentage surface microhardness change (% SMC) was assessed using a microhardness tester. Data were analyzed by Kruskal-Wallis and Dunn's tests (p < 0.05)., Results: The treatments with Elmex™ and resveratrol (1, 10 and 100 µg/mL) significantly protected enamel compared to the negative control, without significant differences among them. However, the group treated with the highest resveratrol concentration (400 µg/mL) did not show a significant difference from the negative control., Conclusions: Resveratrol at concentrations ranging from 1 to 100 µg/ml was effective in preventing loss of enamel surface microhardness., Clinical Significance: This result suggests a potential new direction for the development of dental products based on resveratrol for the prevention of dental erosion., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023. Published by Elsevier Ltd.)

Pellicle is the initial proteinaceous layer that is formed almost instantaneously on all solid surfaces in the oral cavity. It is of essential relevance for any interactions and metabolism on the tooth surface. Up to now, there is no information on the metabolome of this structure. Accordingly, the present study aims to characterise the metabolomic profile of in-situ pellicle in children with different caries activity for the first time in comparison to saliva. Small molecules such as carbohydrates, amino acids, organic acids, and fatty acids, putatively involved in the formation of caries were quantified using mass spectrometry (MS)-based techniques, such as (stable isotope dilution analysis)-ultra-performance liquid chromatography-tandem MS and gas chromatography/electron ionisation-MS. Pellicle and corresponding saliva samples were collected from caries-active, caries-free and caries-rehabilitated 4- to 6-year-old children. The most abundant analytes in pellicle were acetic acid (1.2–10.5 nmol/cm2), propionic acid (0.1–8.5 nmol/cm2), glycine (0.7–3.5 nmol/cm2), serine (0.08–2.3 nmol/cm2), galactose (galactose + mannose; 0.035–0.078 nmol/cm2), lactose (0.002–0.086 nmol/cm2), glucose (0.018–0.953 nmol/cm2), palmitic acid (0.26–2.03 nmol/cm2), and stearic acid (0.34–1.81 nmol/cm2). Significant differences depending on caries activity were detected neither in saliva nor in the corresponding pellicle samples. [ABSTRACT FROM AUTHOR]

The salivary pellicle plays an important role in oral physiology, yet noninvasive in situ characterization and mapping of this layer remains elusive. The goal of this study is to develop an optical approach for the real-time, noninvasive mapping and characterization of salivary pellicles using optical coherence tomography (OCT) and optical coherence microscopy (OCM). The long-term goals are to improve diagnostic capabilities in the oral cavity, gain a better understanding of physiological and pathological processes related to the oral hard tissues, and monitor treatment responses. A salivary pellicle is incubated on small enamel cubes using human whole saliva. OCT and OCM imaging occurs at 0, 10, 30, 60 min, and 24 h. For some imaging, spherical gold nanoparticles (15 nm) are added to determine whether this would increase the optical signal from the pellicle. Multiphoton microscopy (MPM) provides the baseline information. In the saliva-incubated samples, a surface signal from the developing pellicle is visible in OCT images. Pellicle "islands" form, which increase in complexity over time until they merge to form a continuous layer over the enamel surface. Noninvasive, in situ time-based pellicle formation on the enamel surface is visualized and characterized using optical imaging.

Bleaching systems and thickening agents lead to changes in the tooth enamel matrix as a result of an unspecific oxidation of the bleaching gel in the enamel. This reaction may result in a loss of mineral content and a decrease in microhardness. The aim of this study was to evaluate the effects of different bleaching systems and their thickening agents on the microhardness of human enamel in situ. Two dental slabs (3 × 3 × 2 mm) obtained from third molars were fixed on the buccal facial aspects of the maxillary first molars in a group of 45 volunteers. The volunteers were treated with 10% carbamide peroxide gel with carbopol as the thickening agent (group 1), 2% carbopol gel (group 2), 10% carbamide peroxide paste with poloxamer as the thickening agent (group 3), poloxamer (group 4), or 6.5% hydrogen peroxide strips for 21 days (group 5) (experimental treatment factor). The effects of the experimental treatment were evaluated by microhardness tests performed both before and after treatment (time factor). Data were submitted to split-plot analysis of variance and Tukey tests. Only time showed a statistically significant difference (P < .0001). All treatments reduced the enamel microhardness during treatment. Clinically, a reduction in microhardness can be expected after dental bleaching. [ABSTRACT FROM AUTHOR]

Purpose: The objective of the study was firstly to examine the surface morphology of enamel under scanning electron microscopy (SEM), following Er:YAG laser ablation and conventional high-speed bur preparation, with and without acid etching, and secondly to investigate the adhesion of composite resin (CR) to those surfaces by means of a shear bond strength (SBS) test. Materials and Methods: The buccal surface of 42 human extracted molars were ground flat using 500-grit silica carbide paper under water. The surfaces were subjected to simulated cavity preparation treatment and placed into groups: (1) Er:YAG laser ablation (350 mJ,10 Hz, VSP), (2) Er:YAG ablation plus acid etching (37% phosphoric acid), (3) conventional bur (Diamond Fis Z10), (4) conventional bur plus acid etching. Three teeth from each group (n = 3) were examined under SEM (Philips XL 30) to determine the nature of the treated surface. The remaining teeth in each group (n = 10), except group 3, underwent an SBS test to investigate the bond strength of CR to those surfaces, using a universal testing machine (Hounsfield; Hounsfield, UK) following ISO standard TR 11405. Results: Er:YAG laser irradiation resulted in roughened, irregular whitish enamel surfaces, resembling a typical Type I or Type II acid-etch pattern. Surfaces prepared by conventional high-speed bur exhibited a diffuse smear layer that was removed following acid etching. Shear bond strength testing revealed that there was no statistically significant difference in values between acid-etched/laser-ablated (15.89 MPa ± 1.90) and conventionally prepared and etched enamel surfaces (16.55 MPa ± 3.88) (p > 0.05). However, samples of Er:YAG irradiation without acid etching produced significantly lower (p < 0.05) SBS values (10.10 MPa ± 3.57). Discussion: Er:YAG laser irradiation produced surfaces visually similar to an acid-etch pattern, although without a smear layer. Both the conventional bur- and laser-prepared samples exhibited similar surfaces following acid etching. Enamel bond strength produced by Er:YAG laser ablation is comparable to that obtained by the conventional bur. However, within the limitations of this study, Er:YAG irradiation alone cannot be recommended as a viable alternative to acid etching to increase bond strength to enamel. Conclusion: It was concluded that the Er:YAG laser compared very favourably with the conventional bur in preparing enamel surfaces for restoration with composite resin. Of clinical significance, however, is that while the surface produced by the Er:YAG laser is similar to the conventionally prepared, etched enamel surface, it still requires acid etching to obtain an equivalent bond strength. [ABSTRACT FROM AUTHOR]

The article examines whether or not there can occur some permanent damage to the teeth and periodontium with interproximal enamel reduction. It explains the principle of enamel removal with stripping, which is to recontour abnormally shaped teeth toward a more ideal morphology. Several different techniques are said to be used for interdental stripping, with hand-held or motor-driven abrasive strips and handpiece-mounted diamond coated discs or tungsten carbide or diamond burs as the most common. It also discusses a study on iatrogenic effects of stripping.

Purpose: To investigate comparative ablation rate and morphological aspects of different composite resins and dental hard tissues after Er:YAG laser irradiation, with the aim of developing a new clinical technique for the selective removal of restorations and tooth substance. Materials and Methods: We used 11 exfoliated primary anterior and posterior teeth and 6 extracted permanent molars. Three different types of composite resin were chosen (microfilled, hybrid, and condensable) in terms of chemical and structural composition. Composite disks and the teeth were irradiated with an Er:YAG laser under different conditions and energy levels per pulse (100, 200, 300, and 400 mJ). The resulted values were plotted and fitted to allow a comparative observation of the material removed as a function of energy level per pulse. Results: While selective ablation seems to be applicable for the enamel of primary and permanent teeth, it does not apply well to primary or permanent dentin. For dentin, the composition and content of water makes the Er:YAG laser ablation rate equal or superior to that found for the three resins used. Conclusion: The goal of this study, ie, to propose a new clinical technique, was met. It is clear from our results that differential ablation of composite resin restorations using Er:YAG is practicable where enamel surfaces are involved, because their more mineralized composition makes the tissue more resistant to this laser system. Clinically, this new technique presents the Er:YAG laser as an interesting and unique tool in esthetic procedures which also preserves healthy dental hard tissues. [ABSTRACT FROM AUTHOR]

Objective: The composition of the salivary interface (pellicle) between dental restorations and oral mucosa may be critical to the biocompatibility of the restoration. The purpose of this study was to examine the molecular composition of the salivary pellicle on nickel-chromium alloy in vivo. Method and materials: The molecular components of nickel-chromium pellicle was examined with sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western blot analyses. Results: Only limited numbers of salivary proteins were found to participate in the formation of nickel-chromium pellicle in vivo. Salivary amylase and secretory immunoglobulin A were among the proteins identified in the pellicle. Conclusion: In vivo, nickel-chromium pellicle consists of selectively adsorbed salivary proteins. Because both salivary amylase and secretory immunoglobulin A are antimicrobial proteins, it is possible that they play a role in modulating the microbial flora on the nickel-chromium prosthesis. (Quintessence Int 2Q02;33:731-735) [ABSTRACT FROM AUTHOR]

Purpose: The aim of this in vitro study was to analyze the morphology, diameter, depth, and volume of the cavities prepared in deciduous teeth using laser. Materials and Methods: Fourteen exfoliated teeth were irradiated with Er:YAG laser set at 200 mJ and 300 mJ of energy per pulse and a frequency of 10 Hz, applied for 10 s. The morphology, diameter, and depth of the cavities were measured on scanning electron micrograpbs using a modified cephalometric program, and the volume was calculated taking all these parameters into account. Results: The cavities presented a round shape. and a pattern of flakes or scales was observed in the ablated region. There was no significant statistical difference in the diameter of the cavities when 200 mJ (1033.37 μm) or 300 mJ (1083.75 μm) were used. The depth was statistically greater when the energy was increased (153.69 mm and 296.67 μm at 200 and 300 mJ, respectively). The volume also increased when 300 mJ was used. Conclusion: SEM observations showed that the cavities produced were round or slightly oval. The diameter was not affected by energy level, but the higher energy lever increased the depth and volume of the cavities. [ABSTRACT FROM AUTHOR]

Aim: To describe in detail the stripping technique, or interproximal enamel reduction. Material and Methods: Following a careful literature review, this article discusses the interproximal enamel reduction techniques currently available and presents two clinical cases. The indications, contraindications, advantages, disadvantages, and precautions of interproximal enamel reduction are discussed. Results and Conclusion: Orthodontists can effectively use interproximal enamel reduction techniques in many aspects of clinical practice. There is no evidence that, when utilized correctly and in selected clinical situations, interproximal enamel reduction causes harm to the dental hard tissues or soft tissues. [ABSTRACT FROM AUTHOR]

Introduction: This study investigated the changes in the acquired enamel pellicle (AEP) proteome when this integument is formed in vivo after treatment with sugarcane-derived cystatin (CaneCPI-5), hemoglobin (HB), and a statherin-derived peptide (StN15), or their combination and then exposed to an intrinsic acid challenge. The effectiveness of these treatments in preventing intrinsic erosion was also evaluated., Methods: Ten volunteers, after prophylaxis, in 5 crossover phases, rinsed with the following solutions (10 mL, 1 min): control (deionized water-H2O) - group 1, 0.1 mg/mL CaneCPI-5 - group 2, 1.0 mg/mL HB - group 3, 1.88 × 10-5M StN15 - group 4, or a blend of these - group 5. Following this, AEP formation occurred (2 h) and an enamel biopsy (10 µL, 0.01 m HCl, pH 2.0, 10 s) was conducted on one incisor. The biopsy acid was then analyzed for calcium (Arsenazo method). The vestibular surfaces of the other teeth were treated with the same acid. Acid-resistant proteins in the residual AEP were then collected and analyzed quantitatively via proteomics., Results: Compared to control, treatment with the proteins/peptide, mixed or isolated, markedly enhanced acid-resistant proteins in the AEP. Notable increases occurred in pyruvate kinase PKM (11-fold, CaneCPI-5), immunoglobulins and submaxillary gland androgen-regulated protein 3B (4-fold, StN15), Hb, and lysozyme C (2-fold, StN15). Additionally, a range of proteins not commonly identified in the AEP but known to bind calcium or other proteins were identified in groups treated with the tested proteins/peptide either in isolation or as a mixture. The mean (SD, mM) calcium concentrations released from enamel were 3.67 ± 1.48a, 3.11 ± 0.72a, 1.94 ± 0.57b, 2.37 ± 0.90a, and 2.38 ± 0.45a for groups 1-5, respectively (RM-ANOVA/Tukey, p &lt; 0.05)., Conclusions: Our findings demonstrate that all treatments, whether using a combination of proteins/peptides or in isolation, enhanced acid-resistant proteins in the AEP. However, only HB showed effectiveness in protecting against intrinsic erosive demineralization. These results pave the way for innovative preventive methods against intrinsic erosion, using "acquired pellicle engineering" techniques., (© 2024 S. Karger AG, Basel.)

Introduction: Erosive tooth wear is a highly prevalent dental condition that is modified by the ever-present salivary pellicle. The aim of the present in situ study was to investigate the effect of polyphenols on the ultrastructure of the pellicle formed on dentin in situ and a subsequent erosive challenge., Methods: The pellicle was formed on bovine dentin specimens for 3 min or 2 h in 3 subjects. After subjects rinsed with sterile water (negative control), 1% tannic acid, 1% hop extract, or tin/fluoride solution containing 800 ppm tin and 500 ppm fluoride (positive control), specimens were removed from the oral cavity. The erosive challenge was performed on half of the specimens with 1% citric acid, and all specimens were analyzed by transmission electron microscopy. Incorporation of tannic acid in the pellicle was investigated by fluorescence spectroscopy., Results: Compared to the negative control, ultrastructural analyses reveal a thicker and electron-denser pellicle after application of polyphenols, in which, according to spectroscopy, tannic acid is also incorporated. Application of citric acid resulted in demineralization of dentin, but to a lesser degree when the pellicle was pretreated with a tin/fluoride solution. The pellicle was more acid-resistant than the negative control when modified with polyphenols or tin/fluoride solution., Conclusion: Polyphenols can have a substantial impact on the ultrastructure and acid resistance of the dentin pellicle, while the tin/fluoride solution showed explicit protection against erosive demineralization., (© 2024 The Author(s). Published by S. Karger AG, Basel.)

Objective: Evaluate CaneCPI-5 associated with Vitamin E in acquired enamel pellicle (AEP) engineering to prevent dental erosion., Methods: 180 human enamel specimens were divided into 12 groups and treated with the following solutions: Cane+VitT and Cane+VitS- CaneCPI-5 + Vit E; Vit+CaneT and Vit+CaneS- Vit E + CaneCPI-5; VitT and VitS- Vit E; CaneT and CaneS- CaneCPI-5; ControlT and ControlS - AmF/NaF/SnCl 2 ; WaterT and WaterS- Deionized water. Groups' name followed by "T" were first treated (200 μl; 2 min) and then incubated in human saliva (200 μl; 1 h) to form the AEP. For groups followed by "S", the AEP was formed and then treatment was applied. The erosive challenge consisted of immersion in 1% citric acid (1 min, 1x/day, for 3 days). The percentage of superficial hardness loss (%SHL) and the relative surface reflection intensity (%SRI) were subjected to normality and homogeneity tests, Shapiro-Wilk and Levene tests, respectively. Subsequently, the data were analyzed using two-way ANOVA, Tukey's test and Pearson's correlation (p < 0.005)., Results: For%SHL and%SRI, water controls showed significantly lower protective capacity. Cane+VitT, Cane+VitS, and Vit+CaneS presented the lowest%SHL, and VitT and VitS did not differ from Vit+CaneT, but they were different from the other groups (p = 0.002). The greatest%SRI was found for the Cane+VitT, Vit+CaneT, VitT, Cane+VitS, Vit+CaneS, and VitS groups, which did not significantly differ. CaneT and ControlT, showed similar reflections compared to CaneS and ControlS., Conclusion: CaneCPI-5 and Vitamin E demonstrated a synergistic protective effect against initial erosion., Clinical Significance: The results open up new possibilities for preventive approaches against erosion through the acquired pellicle engineering, with the combination of CaneCPI-5 and Vitamin E, which demonstrated to be more effective than commercial stannous mouthwash. Further research is warranted to explore the potential of this combination in diverse clinical settings., Competing Interests: Declaration of Competing Interest The authors declare that they have no conflict of interest., (Copyright © 2023. Published by Elsevier Ltd.)

Objective: The purpose of this study was to determine the degradation of 10% carbamide peroxide within the first hour of use and the effect of pellicle on the degradation of carbamide peroxide in vivo. Method and materials: Fifteen subjects were assigned to wear nightguard trays filled with bleaching gel for 0.5, 2.5. 5.0. 10.0, 20.0, 40.0, and 60.0 minutes under 2 conditions: (1) subjects did not receive a prophylaxis before each bleaching treatment (pellicle was assumed to be present on the tooth surface); and (2) subjects received prophylaxis to remove pellicle from the tooth surface. At each evaluation time, 3 types of sample were collected: (1) a "grab sample," a sample of gel taken with a spatula from the reservoir of the tray on the maxillary right central incisor; (2) the remaining gel from the tray; and (3) the remaining gel scraped from the teeth. The collected gel samples were analyzed for the amount of peroxide using the United States Pharmacopeia-accepted method. Subjects were asked not to swallow the saliva during the treatment but to expectorate into a beaker. The collected saliva was analyzed to determine the amount of peroxide. This sample represented the approximate amount of peroxide that subject would ingest during treatment. Results: Pellicle did not affect the degradation of carbamide peroxide for the teeth or grab samples. The degradation of carbamide peroxide was exponential, except during the first 5 minutes, when the degradation rate was much higher. The saliva collected from subjects during use of the bleaching tray revealed an average of 2.1 mg of carbamide peroxide for 1 hour of bleaching treatment. Conclusion: The degradation rate is not affected by the removal of the pellicle. (Quintessence Int 1999;30:737-741) [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • First systematic examination of the in situ pellicle thickness. • Ellipsometry is a powerful method for measurements of pellicle thickness. • A physiologically important rapid initial pellicle formation stage was detected. • Inter-individual and formation kinetics differences were found. • Oral location had a lower impact on pellicle thickness than individual influence. Abstract The salivary pellicle is a thin acellular film formed on orally exposed surfaces by adsorption of macromolecules from the oral fluids and serves as a protective layer in the maintenance of oral health. Pellicle thickness measurements are a central tool helping to understand how exogenous manipulations may influence pellicle formation. This is of particular importance for the investigation of new preventive and therapeutic approaches. In the present study we determined the kinetics of the in situ pellicle thickness formation at different intraoral sites and investigated how pellicle formation occurs in different individuals. To address the kinetic aspect, the thickness of the in situ pellicle was determined after formation periods of 3 min, 30 min and 120 min. The thickness of the pellicle was either measured on silicon wafers by ellipsometry or on bovine enamel by transmission electron microscopy. We found a physiologically important rapid pellicle formation phase within the first minutes and a slow pellicle formation phase between 30 min and 120 min. Furthermore, our results identify significant inter-individual differences both for the pellicle thickness and for the formation kinetics, indicating the consideration of individual-specific differences of the pellicle layer as an important aspect for future studies. [ABSTRACT FROM AUTHOR]

Abstract The aim of this work was to test the use of plant-based natural dyes on bacterial cellulose (BC) to add aesthetic value to dyed pellicles while maintaining the mechanical properties. Natural pigments from Clitoria ternatea L. and Hibiscus rosa-sinensis were tested. The commercial ARAQCEL RL 500 was also used for comparison purposes. The behavior of biocellulose regarding dye fixation, rehydration, tensile strength, and elasticity was evaluated in comparison to the dried biomaterial, showing that dyeing is a process that can be performed on hydrated BC. Dyeing the BC films through an innovative process maintained the crystallinity, thermal stability and mechanical strength of the BC and confirmed the compatibility of the membrane with the dyes tested, from the observed Scanning Electron Microscopy (SEM) morphology of nanofibers. Dyed biomaterial can be applied to various products, as confirmed by the results of the mechanical tests. As environmental awareness and public concern regarding pollution increase, the combination of natural dyes and BC pellicles can produce an attractive new material for the textile industry. Highlights • Plant base natural dyes were tested in bacterial cellulose (BC) pellicles dying. • Clitoria ternatea L. and Hibiscus rosa-sinensis pigments were tested. • Dye fixation, tensile strength and elasticity was observed for BC pellicles. • Dyeing can be performed on the hydrated BC pellicles. • The dyed biomaterial can be applied to various artifacts. [ABSTRACT FROM AUTHOR]

Resistance to acid demineralization provided by luting agents adjacent to enamel was evaluated for four different luting agents: composite resin, glass ionomer, polycarboxylate, and zinc phosphate cement. Cement solubility and enamel demineralization after acid attack at pH 3.0 were measured radiographically and calculated using computer-aided design. Tensile bond strength of a miniature crown seated on an accurately prepared preparation was evaluated after acid attack using an Instron instrument. Crown retention after 12 days was greater for the polycarboxylate (2,000 kg/m²) than the zinc phosphate cement (500 kg/m²). Crown retention for the glass ionomer (1,100 kg/m²) and composite resin luting agent (1,400 kg/m²) were similar statistically after 21 days of acid exposure. Cement washouts for zinc phosphate and polycarboxylate were similar, and were greater than either glass ionomer or composite resin luting agent. The amount of demineralization related to cements was, from greatest to least: zinc phosphate, polycarboxylate, composite resin, glass ionomer. Fluoride release was concluded to be initially effective in reducing enamel solubility in spite of cement solubility. [ABSTRACT FROM AUTHOR]

The article discusses the method of nightguard vital bleaching, a bleaching method used for treating discolored teeth. This technique involves acid etching the enamel with 37 percent phosphoric acid, and then bleaching the teeth by applying 30 percent hydrogen peroxide to the tooth surfaces. After this heat exposure is given. The time required for effective bleaching is generally 20 to 30 minutes using the heat lamp, or approximately two minutes per tooth when using a heating element, although times vary with tooth sensitivity.

The objective of this study was to assess the effects of in situ saliva compared to in vitro human saliva, with or without mucin, on inhibiting erosion and promoting enamel rehardening. Bovine enamel blocks were randomly distributed into groups (n = 23): Gsitu (human saliva in situ), Gvitro (collected human saliva) and GvitroM (collected human saliva with mucin). The enamel blocks underwent a 2-hour period for the formation of salivary pellicle, based on the assigned groups. Subsequently, they were subjected to three erosive cycles, each of them consisting of an erosive challenge (immersion in 0.65 % citric acid, pH 3.5, 1 min) and saliva exposure (immersion in situ or in vitro saliva for 2 h). Microhardness measurements were performed at each cycle, after each experimental step (erosive challenge and exposure to saliva). After the first demineralization, in vitro saliva groups presented greater hardness loss, with no statistical difference between GVitroM and GVitro. After the third erosive demineralization the in situ saliva resulted in less hardness loss compared to the first demineralization. In relation to surface hardness recovery, there was no difference among types of saliva but there was a decrease in hardness as the cycles progressed. Saliva groups had different behaviors between the first and third demineralization, being similar after the third cycle in terms of hardness loss. Regarding hardness recovery, all saliva promoted enamel gain, but there was a gradual decrease with the progression of the cycles. • Saliva demonstrated a limited ability for mineral redeposition. • Protection of acquired pellicle is limited, especially during longer acid exposure. • Collected human saliva can replace the artificial one in laboratory studies. [ABSTRACT FROM AUTHOR]

Background: The dental pellicle is a thin layer of up to several hundred nm in thickness, covering the tooth surface. It is known to protect the teeth from acid attacks through its selective permeability and it is involved in the remineralization process of the teeth. It functions also as binding site and source of nutrients for bacteria and conditioning biofilm (foundation) for dental plaque formation., Methods: For this updated literature review, the PubMed database was searched for the dental pellicle and its composition., Results: The dental pellicle has been analyzed in the past years with various state-of-the art analytic techniques such as high-resolution microscopic techniques (e.g., scanning electron microscopy, atomic force microscopy), spectrophotometry, mass spectrometry, affinity chromatography, enzyme-linked immunosorbent assays (ELISA), and blotting-techniques (e.g., western blot). It consists of several different amino acids, proteins, and proteolytic protein fragments. Some studies also investigated other compounds of the pellicle, mainly fatty acids, and carbohydrates., Conclusions: The dental pellicle is composed mainly of different proteins, but also fatty acids, and carbohydrates. Analysis with state-of-the-art analytical techniques have uncovered mainly acidic proline-rich proteins, amylase, cystatin, immunoglobulins, lysozyme, and mucins as main proteins of the dental pellicle. The pellicle has protective properties for the teeth. Further research is necessary to gain more knowledge about the role of the pellicle in the tooth remineralization process., Competing Interests: JS, ES, and FM are employees of Dr. Kurt Wolff GmbH & Co KG. The remaining authors declare that the research was conducted in the absence of any commercial of financial relationships that could be construed as a potential conflict of interest., (© 2023 Enax, Ganss, Amaechi, Schulze zur Wiesche and Meyer.)

Bacterial cellulose (BC) is one of the prominent biopolymers that has been acquiring attention currently due to its distinctive properties and applications in various fields. The current work presents the isolation of Komagataeibacter saccharivorans strain BC1 isolated from rotten green grapes, followed by biochemical and genotypic characterization, which confirmed that the strain is capable of synthesizing cellulose. Further, production media was designed and certain variables such as carbon, nitrogen sources, pH, and temperature were optimized in order to obtain the maximum concentration of cellulose production. We found mannitol to be the ideal carbon source and yeast extract as the ideal nitrogen source with a highest BC dry yield of 1.81 ± 0.25 g/100 mL at pH 5.76 for a week at 30 °C.The charcterization of pellicles by FTIR spectrum depicted similar functional groups present in synthesized BC as that of the commercial cellulose. X-ray diffraction revealed that BC showed 82% crystallinity. Surface morphology of the dried pellicle was studied by SEM image which showed that the BC surface was tightly packed with thin fibers with less porosity. Hence the study demonstrates that the isolates of K.saccharivorans could be used to produce a biopolymer in a short period of time using a modified production medium. [ABSTRACT FROM AUTHOR]

The interaction of tannins with salivary proteins is involved in astringency. This paper focussed on saliva lining oral mucosae, the mucosal pellicle. Using a cell-based model, the impact of two dietary tannins (EgC and EgCG) on the mucosal pellicle structure and properties was investigated by microscopic techniques. The role of basic Proline-Rich-Proteins (bPRPs) in protecting the mucosal pellicle was also evaluated. At low (0.05 mM) tannin concentration, below the sensory detection threshold, the distribution of salivary mucins MUC5B on cells remained unaffected. At 0.5 and 1 mM, MUC5B-tannin aggregates were observed and their size increased with tannin concentration and with galloylation. In addition, 3 mM EgCG resulted in higher friction forces measured by AFM. In presence of bPRPs, the size distribution of aggregates was greatly modified and tended to resemble that of the “no tannin” condition, highlighting that bPRPs have a protective effect against the structural alteration induced by dietary tannins. [ABSTRACT FROM AUTHOR]

This study detected changes in the protein profile of the acquired enamel pellicle (AEP) formed in vivo after rinsing with whole milk, fat-free milk, or water. Nine subjects in good oral condition took part in the study. The acquired pellicle was formed in the morning, for 120 min, after prophylaxis with pumice. Following this, the volunteers rinsed with 10 mL of whole milk, fat-free milk, or deionized water for 30 s, following a blinded crossover protocol. After 60 min, the pellicle was collected with filter paper soaked in 3% citric acid and processed for analysis by liquid chromatography-electrospray ionization tandem mass spectrometry. The obtained tandem mass spectrometry spectra were searched against a human protein database (Swiss-Prot). The proteomic data related to protein quantification were analysed using the PLGS software. A total of 260 proteins were successfully identified in the AEP samples collected from all groups. Forty-nine were common to all 3 groups, while 72, 62, and 49 were specific to the groups rinsing with whole milk, fat-free milk, and water, respectively. Some were typical components of the AEP, such as cystatin-B, cystatin-SN, isoforms of α-amylase, IgA and IgG, lysozyme C, protein S100 A78, histatin-1, proline-rich protein 27, statherin, and lactotransferrin. Other proteins are not commonly described as part of the AEP but could act in defence of the organism against pathogens. Distinct proteomic profiles were found in the AEP after rinsing with whole or fat-free milk, which could have an impact on bacterial adhesion and tooth dissolution. The use of fat-free milk could favourably modulate the adhesion of bacteria to the AEP as well as biofilm formation when compared with whole milk. [ABSTRACT FROM AUTHOR]

Introduction: Dental erosion is defined as the pathological, irreversible, chronic, and localised loss of dental enamel by prolonged acid action and often without bacterial involvement. Aim: To evaluate ex vivo, the erosive potential of widely consumed teas in Brazil by measuring the pH, titratable acidity of beverages and the roughness and surface microhardness of dental enamel before and after erosive challenges. Materials and Methods: Thirty human maxillary third molars, extracted for clinical reasons and obtained from Human Teeth Bank of the Dental School from 8th May 2017 to 18th May 2017 (Federal University of Juiz de Fora), were used to perform erosive cycles, which were exposed to Morinda citrifolia, Uncaria tomentosa, Caesalpinia ferrea, Schizolobium amazonicum, Schinus aroeira teas and 1% citric acid. The samples were immersed in the solutions for two minute, five times a day, at intervals of two hours for four days. Between the erosive cycles, the specimens remained in artificial saliva. Statistical analyses were performed using the IBM SPSS statistics 22.0 software. The accepted significance was set has p-value <0.05. Results: The mean pH of the five samples ranged from 3.55 to 5.55 and all the herbal teas tested showed significant buffering capacity. The results suggested that all acid teas in the study have an erosive potential. The microhardness ranged from 34.12 to 46.98, and no significant difference was observed between groups in relation to the control group (1% citric acid). The roughness results for M. citrifolia and U. tomentosa teas were similar to those of the control group. Conclusion: The analysis of the data allows for the conclusion that all the teas present with acid pH and presence of ions capable of interacting with the dental surface and causing loss of dental tissue, reducing the microhardness of the enamel. Thus, there is a need to be careful in consuming such beverages. [ABSTRACT FROM AUTHOR]

Objective In this study, we aimed to investigate denture-base-resin coatings prepared with a crosslinkable co-polymer containing sulfobetaine methacrylamide (SBMAm) and the relationship between their surface characteristics and the initial adhesion of Candida albicans ( C. albicans ). Methods Acrylic resin discs were coated with co-polymers containing various concentrations of SBMAm and N,N ’-(4,7,10-trioxa-1,13-tridecadiamine) diacrylamide (JDA) as crosslinking agent. Uncoated discs were used as controls. An acquired pellicle was formed on each disc using artificial saliva, and the discs were immersed in a suspension of C. albicans (JCM2085) cells. After incubation, tetrazolium salt (XTT-reduction) and colony forming unit (CFU) assays were performed and the morphogenesis of C. albicans was examined using scanning electron microscopy (SEM). The surface roughness, film thickness, and the water contact angle of each disc surface were measured. Results All coating groups showed significantly lower amounts of adhered C. albicans in the XTT-reduction and CFU assays than the control, confirmed by the SEM images. Many wrinkle structures were observed on the surfaces coated with co-polymers containing more than 30% SBMAm. There were no significant differences in surface roughness among all groups. The co-polymer films on the coated discs were less than 5.0 μm in thickness, and these surfaces exhibited significantly lower mean water contact angles than the control. Conclusion Crosslinkable co-polymers containing SBMAm can enhance the hydrophilicity of the surface of denture-base resins and reduce the initial adhesion of C. albicans. [ABSTRACT FROM AUTHOR]

Objective Investigate the effects of dentin pretreatment with 2.5% titanium tetrafluoride (TiF 4 ) aqueous solution followed by two-step self-etching (CLE/Clearfil SE Bond) and one-step self-etching adhesive systems (SBU/Single Bond Universal) on carious lesion inhibition at the tooth-restoration interface using an in situ model. Design Sixty-four cavities at the enamel-dentin junction of dental fragments were randomly distributed according to groups (n = 16): 1) TiF 4 + CLE; 2) TiF 4 + SBU; 3) CLE; 4) SBU. Cavities were restored using resin composite, and placed in intraoral palatal devices used by 16 volunteers for 21 days, to induce caries formation in situ . The fragments were then ground-flat to perform Knoop microhardness tests. Nine indentations were performed on each enamel and dentin substrate, subjacent to the restoration. Analysis of variance and Tukey’s test were applied. Results Enamel: groups receiving TiF 4 dentin pretreatment (regardless of adhesive system and tooth-restoration interface distance) presented higher hardness means at a depth of 25 μm from the outer tooth surface (p < 0.0001). Dentin: groups receiving CLE presented higher means when applying TiF 4 pretreatment, whereas groups restored with SBU presented higher means without pretreatment (p = 0.0003). Conclusions Dentin pretreatment with TiF 4 inhibited demineralization of the enamel interface in situ , regardless of the adhesive, and TiF 4 pretreatment followed by CLE application showed higher potential for inhibiting dentin demineralization at the interface. [ABSTRACT FROM AUTHOR]

Human saliva consists of approximately 98% water and a variety of electrolytes and proteins. Those proteins can be selectively adsorbed onto the enamel surface. The cuticular material formed on the enamel surface is termed acquired salivary pellicle (ASP), which is critical for the health of oral mucosa and teeth. The ASP is composed of a inner layer and a outer layer. The lubricating properties of ASP are closely associated with the inner layer. The aim of this research is to characterize the structural and mechanical properties of the inner layer of ASP. In this paper, enamel specimens were immersed for 1 min in human saliva. The ASP formed in vitro within 1 min was studied using a nanoindenter. The results show that the thickness of the inner layer of ASP is approximately 18 nm. Moreover, the inner layer is a heterogeneous pellicle with a gradient in density. From the surface of the inner layer to the enamel surface, the density and mechanical properties gradually increase. The research results may be helpful to extend the understanding of mechanical properties of salivary pellicle and to the oral hygiene industry for diagnose oral diseases. [ABSTRACT FROM AUTHOR]

Hydroxyapatite-based implant is widely used in the fields of artificial teeth and bones. However, the problem of microbial communities on hydroxyapatite surfaces remain a great challenge. In order to inhibit bacterial adhesion and activity in a long term, a salivary acquired pellicle (SAP) bioinspired tannic acid (SAP3-TA) is synthesized and characterized. The SAP inspired peptide sequence DDDEEK has a good adsorption performance on the surface of hydroxyapatite (HA). Tannic acid (TA) is a natural polyphenolic compound that can be extracted from green tea, and it has been proved to have an effective antibacterial property. After the coating of SAP3-TA on HA slices, the water contact angle is decreased to 14.2° and the HA surface becomes super-hydrophilic. The hydrophilic surface can prevent proteins adhesion and further inhibit the adhesion of bacteria. In this work, Streptococcus mutans ( S. mutans ) and bovine serum albumin (BSA) are used as models to prove the antibacterial and anti-biofouling properties of SAP3-TA coating on HA surface, respectively. SAP3-TA also shows low cytotoxicity to MG63 cells in the MTT test. All these results indicate that the SAP3-TA can be used as a potential antibacterial and anti-biofouling coating for hydroxyapatite-based implants. [ABSTRACT FROM AUTHOR]

Enamel defects have a wide range of aetiology and can be challenging to diagnose. Largely, the management of enamel defects is determined by the severity. As most patients with enamel defects present at a young age, conservative treatment is a priority. Nevertheless, indirect restorations have a role in restoring severely broken down teeth. This article discusses the diagnosis and management of identical twins with molar-incisor hypomineralization (MIH). Many of the techniques discussed can be applied to a wide presentation of enamel defects and are not limited to the management of MIH. CPD/Clinical Relevance: The restorative management of enamel defects can be challenging but priority should be given to conservative treatment techniques for young patients. [ABSTRACT FROM AUTHOR]

Objectives: This study tested the effect of enamel salivary exposure time prior to an acid challenge (30 min, 1, 2, or 12 h) and type of intraoral appliance (palatal or mandibular) on initial erosion. Methods: After initial surface hardness evaluation, enamel blocks ( n = 340) were randomly divided into groups and volunteers ( n = 20). The control group was not exposed to saliva previously to the erosive challenge. The volunteers wore palatal and mandibular appliances simultaneously. After salivary exposure, the blocks were subjected to acid exposure by immersion in hydrochloric acid (0.01 M, pH 2.3) for 30 s. Then, the enamel surface hardness was evaluated. Data were analyzed using ANOVA, Kruskal-Wallis and Tukey's test ( p < 0.05). Results: No difference was observed on percent surface hardness change (% SHC) in the enamel blocks between the types of intraoral appliances. Exposure to saliva for 30 min and 1 h promoted similar enamel resistance to the erosive attack, which was similar to the control group for both appliances. Blocks exposed to saliva for 2 h showed less hardness loss when compared to 30 min. Keeping the blocks in saliva during 12-h overnight resulted in similar percentage of enamel hardness loss compared to 2 h. Conclusions: A 2-hour in situ exposure to saliva is adequate to promote partial protection against initial erosive lesions, independently of the type of intraoral appliance used. Clinical significance: This finding will help researchers in the development of erosion studies, which will provide information for dentists to offer a better treatment for erosion. [ABSTRACT FROM AUTHOR]

This study was to investigate the salivary pellicle formation on the surface of human tooth enamel and its lubricating behavior under alcohol stimulation. Normal saliva and alcohol-stimulated saliva were collected from a young male volunteer after rinsing mouth with deionized water and different-concentration alcohol aqueous solution, respectively. Saliva-adsorption treatment was conducted in vitro on enamel surface to obtain salivary pellicle. Microscopic examinations and lubrication testing of salivary pellicle were performed by nanoscratch technology. Given that the pellicle lubricating properties are closely associated with its adhesion strength to substrates, the adhesion force between salivary pellicle and enamel was measured using an Atomic Force Microscopy. Compared with normal salivary pellicle, the salivary pellicle obtained from alcohol-stimulated saliva was not uniform anymore and even without any orderly multi-layer structure. Although alcohol stimulation improved the pellicle bonding to enamel surface, it caused the pellicle lubrication worse. In sum, the lubricating performance of salivary pellicle was more dependent on its orderly multi-layer structure from salivary protein self-assembly than its adhesion strength to enamel. [ABSTRACT FROM AUTHOR]