Explore the vast range of titles available.

ObjectiveTo investigate the long-term microtensile bond strength (µTBS), interfacial nanoleakage expression (NL), and adhesive stability of dual-cure resin cements with/out light activation to dentin.Materials and methodsComposite overlays (N = 20) were luted to deep dentin surfaces with RelyX Ultimate (RXU, 3M) or Variolink EstheticDC (VAR, Ivoclar-Vivadent). A universal adhesive was used for bonding procedures (iBond universal, Heraeus Kulzer). The resin cements were either self-cured (SC; 1 h at 37 °C) or dual-cured (DC; 20s light-cure followed by 15 min self-cure at 37 °C). Specimens were submitted to µTBS immediately (T0) or after 1 year of laboratory storage (T12). The fracture pattern was evaluated using scanning electron microscopy (SEM). Data were statistically analyzed with two-way ANOVA/Tukey test. Further, the NL was quantified and analyzed (chi-square test) and in situ zymography was performed to evaluate the endogenous enzymatic activity within the hybrid layer (HL) at T0 and T12 (Mann–Whitney test). The significance level for all statistical tests was set at p = 0.05.ResultsDC resulted in higher bond strength and decreased fluorescence at the adhesive interface, irrespective of the material and the storage period (p < 0.05). Significantly lower bonding performances (p < 0.05) and higher endogenous enzymatic activity (p < 0.05) were observed within the HL at T12 compared to T0 in all tested groups.ConclusionsLight-curing the dual-cure resin cements, more than the cement materials, accounted for good bonding performances and higher HL stability over time when used with a universal adhesive.Clinical significanceThe curing condition influences the bonding performances of dual-cure resin cements to dentin when used with a universal adhesive.

The oral cavity and oropharynx are complex environments that are susceptible to physical, chemical, and microbiological insults. They are also common sites for pathological and cancerous changes. The effectiveness of conventional locally‐administered medications against diseases affecting these oral milieus may be compromised by constant salivary flow. For systemically‐administered medications, drug resistance and adverse side‐effects are issues that need to be resolved. New strategies for drug delivery have been investigated over the last decade to overcome these obstacles. Synthesis of nanoparticle‐containing agents that promote healing represents a quantum leap in ensuring safe, efficient drug delivery to the affected tissues. Micro/nanoencapsulants with unique structures and properties function as more favorable drug‐release platforms than conventional treatment approaches. The present review provides an overview of newly‐developed nanocarriers and discusses their potential applications and limitations in various fields of dentistry and oral medicine. A wide variety of micro/nanoscale platforms are employed for oral and dental applications including tissue regeneration, infection control, and cancer management. Such micro and nanocarriers deliver ions (e.g., fluoride, calcium, strontium), antibiotic, antiviral, antifungal compounds, as well as genes and proteins.

Incomplete and inadequate removal of endodontic biofilm during root canal treatment often leads to the clinical failure. Over the past decade, biofilm eradication techniques, such as sonication of irrigant solutions, ultrasonic and laser devices have been investigated in laboratory settings. This review aimed to give an overview of endodontic biofilm cultivation methods described in papers which investigated sonic-, ultrasonic- and Er:Yag laser-assisted biofilm removal techniques. Furthermore, the effectiveness of these removal techniques was discussed, as well as methods used for the evaluation of the cleaning efficacy. In general, laser assisted agitation, as well as ultrasonic and sonic activation of the irrigants provide a more efficient biofilm removal compared to conventional irrigation conducted by syringe/needle. The choice of irrigant is an important factor for reducing the bacterial contamination inside the root canal, with water and saline being the least effective. Due to heterogeneity in methods among the reviewed studies, it is difficult to compare sonic-, ultrasonic- and Er:Yag laser-assisted techniques among each other and give recommendations for the most efficient method in biofilm removal. Future studies should standardize the methodology regarding biofilm cultivation and cleaning methods, root canals with complex morphology should be introduced in research, with the aim of simulating the clinical scenario more closely.

Orthodontic aligners 3D-printed in resin currently provide a viable alternative to thermoformed ones. However, concerns have been raised regarding their biocompatibility. This review addressed the available scientific evidence on the biological properties of marketed resins for 3D printing of orthodontic aligners, encompassing cytotoxicity, estrogenicity, biofilm formation, and oral soft tissues reactions. A comprehensive literature search of several databases was conducted and PRISMA guidelines were followed to summarize the retrieval. Eleven studies were included in the review. They provided information on only three marketed resins: Tera Harz TC-85 DAC and Tera Harz TA-28 (Graphy) and Clear-A (Senertek). For the last two materials, only one investigation has been performed. Despite the large variability in experimental protocols, the lack of cytotoxicity of Tera Harz TC-85 DAC was a consistent finding. Also, no estrogenic effect was detected for this resin, in line with the lack of any bis-phenol A precursor in its chemical composition. In two clinical studies, oral soft tissue reactions were reported as rare and non-serious occurrences. Biofilm adhesion was regarded as critical for the clinical safety of 3D-printed aligners. Standardization of in vitro protocols, also including more clinically relevant settings, chemical characterization of the resins’ eluates, and collection of additional in vivo data are advised to improve the quality of the evidence.

Background To investigate the effect of 0.3 M 1-ethyl-3(3-dimethylaminopropyl) carbodiimide (EDC) aqueous solution pretreatment on push-out bond strength (PBS) and matrix-metalloproteinases (MMPs) activity within radicular dentin when different post cementation strategies were employed. Methods One hundred and twenty monoradicular human teeth were endodontically treated and randomly divided into six groups, depending on the cementation strategy and root dentin pretreatment (n = 20): EAR: cementation with an etch-and-rinse adhesive (LuxaBond Total Etch, DMG) and resin cement (LuxaCore Z Dual, DMG); EAR/EDC: 1 min EDC pretreatment after etching + EAR; SE: cementation with a self-etch primer (Multilink Primer, Ivoclar Vivadent) and corresponding cement (Multilink Automix, Ivoclar Vivadent); SE/EDC: self-etch primer + EDC pretreatment + SE; SA: cementation with a universal self-adhesive cement (RelyX Universal, 3 M); SA/EDC: EDC pretreatment + SA. Slices were submitted to PBS test and interfacial nanoleakage evaluation 24 h after cementation or after thermocycling (40.000 cycles, 5–55 °C). To investigate the effect of EDC on MMPs activity, 4 additional first maxillary premolars per group were processed for in situ zymography analysis. Multivariate ANOVA and post hoc Tukey tests were used to analyze PBS values. The data from in situ zymography were analyzed with Kruskal-Wallis test and Dunn’s pairwise multiple comparison procedures (α = 0.05). Results The variables “EDC pretreatment”, “root region” and “thermocycling” significantly influenced PBS (p < 0.05), while the variable “cementation strategy” had no influence (p > 0.05). Thermocycling significantly reduced PBS in SE and SA groups (p < 0.05). EDC was effective in preserving PBS after artificial aging. EDC pretreatment significantly reduced enzymatic activity at baseline in EAR and SE groups, and in SA group after thermocycling (p < 0.05). Conclusions The use of EDC prevents the reduction of bond-strength values after artificial aging and silences endogenous enzymatic activity within radicular dentin when different cementation strategies were employed.

The aim of this study was to evaluate the effect of different concentrations of chitosan polymer on dentinal enzymatic activity by means of gelatin and in situ zymography. Human dentin was frozen and ground in a miller. Dentin powder aliquots were demineralized with phosphoric acid and treated with three different concentrations of lyophilized chitosan polymer (1, 0.5 and 0.1 wt%) dissolved in distilled water. Dentin proteins were extracted from each experimental group and electrophoresed under non-reducing conditions in 10% SDS-PAGE containing fluorescein-labeled gelatin. After 48 h in the incubation buffer at 37 °C, proteolytic activity was registered under long-wave UV light scanner and quantified by using Image J software. Furthermore, additional teeth (n = 4) were prepared for the in situ zymographic analysis in unrestored as well as restored dentin pretreated with the same chitosan primers. The registered enzymatic activity was directly proportional to the chitosan concentration and higher in the restored dentin groups (p < 0.05), except for the 0.1% chitosan primer. Chitosan 0.1% only showed faint expression of enzymatic activity compared to 1% and 0.5% concentrations. Chitosan 0.1% dissolved in water can produce significant reduction in MMPs activity and could possibly contribute to bond strength preservation over time.

The purpose of this study was to clarify the structural and ultrastructural alterations of the enamel and dentin collagen network in the deciduous teeth of children affected by osteogenesis imperfecta (OI) using field-emission in-lens scanning electron microscopy (FEI-SEM) and transmission electron microscopy (TEM) analyses. Exfoliated primary teeth were collected from children with a diagnosis of OI and from healthy individuals (N = 24). Tooth slices containing both dentin and enamel were fixed, dehydrated and dried, gold sputtered, and observed using FEI-SEM. Additional dentin fragments were decalcified, dehydrated, embedded in resin, cut, and processed for TEM analysis. Under FEI-SEM, the enamel in OI-affected children showed an irregular prism distribution with the enamel hydroxyapatite crystals unpacked. Ultrastructural correlative analysis of the dentin in patients affected by OI showed an altered collagen pattern with a low density. In some areas, teeth in OI patients showed a reduction in the number of dentinal tubules, with odontoblastic process missing in most of the tubules. The presence of altered dentine and enamel organization in OI children was firmly established at an ultrastructural level, but additional biochemical studies are necessary in order to clarify quantitatively and qualitatively the collagenic and non-collagenic proteins in this disorder.

Several lubricant materials can be used to model resin-based composites (RBCs) during restorative procedures. Clinically, instruments or brushes are wet with bonding agents (BAs) or modeling liquids (MLs) for sculpturing purposes. However, a knowledge gap exists on their effects on the mechanical properties of RBCs, requiring greater insight. Five databases were searched, including 295 in vitro studies on the use of lubricant materials for modeling RBCs during restorative procedures. Only articles in the English language were included, with no limits on the publication date. The last piece of research was dated 24 March 2022. In total, 16 studies were included in the review process, together with a paper retrieved after screening references. A total of 17 BAs and 7 MLs were investigated. Tensile (n = 5), flexural strength (n = 2), water sorption (n = 2), color stability (n = 8) and translucency (n = 3), micro-hardness (n = 4), roughness (n = 3), degree of conversion (n = 3), and monomer elution (n = 2) tests were carried out. In general, a maximum of 24 h of artificial storage was performed (n = 13), while four papers tested the specimens immediately. The present review identifies the possibilities and limitations of modeling lubricants used during restorative procedures on the mechanical, surface, and optical properties of RBCs. Clinicians should be aware that sculpturing RBCs with modeling resins might influence the composite surface properties in a way that is material-dependent.

Resin infiltration is a conservative treatment of initial enamel carious lesions. Only one infiltrant material is available on the market (Icon, DMG), and research is now investigating new chemical compositions so as to further exploit the benefits of the resin infiltration technique. A literature search of the articles testing the effects of different formulations on mechanical properties, resin penetration ability, remineralizing, and antibacterial activities was conducted. Of 238 articles, 29 resulted in being eligible for the literature review. The formulations investigated were all different and consisted in the inclusion of hydrophobic monomers (i.e., BisEMA, UDMA), solvents (ethanol, HEMA), alternative etchants (PAM) or molecules with antibacterial or bioactivity features (i.e., AgNP, YbF3, MTZ, chitosan, DMAMM, HAp, MC-IL, NACP, PUA, CHX) and microfilled resins. Information on the long-term performances of the tested experimental materials were scarce. The combination of TEGDMA with hydrophobic monomers and the inclusion of a solvent alternative to ethanol reinforced mechanical properties of the materials. Hybrid-glass materials demonstrated an enhanced remineralization capacity. Techniques such as tunnelization increased the penetration depth and preserved the recourse to less-conservative treatments. Combining the min-invasive infiltrant approach with remineralizing and bacteriostatic properties would be beneficial for therapeutic and economical aspects, according to the principles of minimally invasive dentistry.

Objectives To evaluate the antibacterial efficacy of two fluoride-containing (1450 ppm F) toothpastes with or without zinc-citrate (ZCT), hydroxyapatite (HAP) and potassium-citrate (KCit); to assess and compare their clinical effects in terms of tooth sensitivity, plaque accumulation and gingivitis, as well as patients’ satisfaction. Materials and methods Healthy, adult patients were selected and randomly assigned to two groups ( n  = 50): Experimental: ZCT-, HAP-, KCit- and fluoride-containing toothpaste; Control: fluoride-containing toothpaste. Salivary counts of Streptococcus mutans (S. mutans) , plaque and gingival index, as well as clinically diagnosed sensitivity were recorded at baseline, and after 4 weeks. A custom-made questionnaire was used to assess patients’ self-reported sensitivity (baseline and after 4 weeks) and overall satisfaction with the tested toothpastes. Data were statistically analyzed (α = 0.05). Results After 4 weeks, a statistically significant salivary reduction of S. mutans was observed in both groups ( p  = 0.001). Furthermore, the percentage of S. mutans decrease was significantly higher in Experimental group ( p  = 0.014). There were no statistically significant differences between the groups in terms of plaque and gingival index ( p  > 0.05). After 4 weeks, the self-reported tooth sensitivity was lower in Experimental group ( p  < 0.001). Conclusions Both toothpastes showed good antimicrobial effect after 4 weeks; however, the toothpaste containing ZCT, HAP, KCit and fluoride was found to be more effective in reducing the salivary counts of S. mutans than the product containing fluoride alone. Clinical relevance Toothpaste containing ZCT, HAP, KCit and fluoride can be recommended for patients at risk for developing caries and may also be beneficial for individuals experiencing dental sensitivity.