Saliva Decreases Sucrose-Induced Cariogenicity in an Experimental Biological Caries Model.

OBJECTIVE: Whether a minimum quantity of saliva inhibit the caries process remains uncertain. This study aimed to investigate the impact of saliva dilutions on an in vitro caries model using Streptococcus mutans (S. mutans) biofilms. METHODS: S. mutans biofilms were cultivated on enamel and root dentin slabs, in culture media containing different proportions of saliva (v/v): 0%, 5%, 10%, 25%, 50%, 75%, and 100% saliva, and exposed to a 10% sucrose solution (5 min, 3x/day), with appropriate controls. After 5 (enamel) and 4 (dentin) days, demineralization, biomass, viable bacteria, and polysaccharide formation were analyzed. The acidogenicity of the spent media was monitored overtime. Each assay was performed in triplicate across two independent experiments (n = 6). RESULTS: In both enamel and dentin, an inverse relationship was observed between acidogenicity, demineralization, and the proportion of saliva. Even small quantities of saliva incorporated into the media led to a noticeable reduction in enamel and dentin demineralization. Saliva presence resulted in significant reductions in biomass, viable S. mutans cells, and polysaccharides, with the effects being concentration-dependent for both tissues. CONCLUSIONS: High quantities of saliva can almost completely inhibit sucrose-induced cariogenicity, while even small amounts exhibit a dose-dependent caries-protective effect.

Understanding dental caries as a non-communicable and behavioral disease: Management implications.

New paradigms in caries conceptualization have emerged during the last decades, leading to intense debate and discussion on how to approach the disease, both from a preventive and a therapeutic perspective. Among many new ideas, research discoveries and technologies, one major concept can be highlighted that created a deep frontier between the old and the new paradigm in caries conceptualization; the non-communicable nature of the disease, firmly associated with behaviors and lifestyles. This article synthetizes the conceptual construction of dental caries as a non-communicable disease (NCD) based on the current evidence and discusses the appropriate management of the disease in this context. Dental caries has shifted from being considered transmissible and infectious to an ecological and non-communicable disease. Environmental factors such as frequent sugars intake, disrupt the symbiosis of the dental biofilm leading to a dysbiosis, which favors caries lesion initiation and progression. As an NCD, dental caries shares characteristics with other NCDs such as cardiovascular and chronic respiratory diseases, cancer and diabetes, including long duration and slow progression, not being transmissible from person-to-person, being strongly related to modifiable behavioral risk factors, and affecting preferentially disadvantaged populations with a strong inequality gradient. Given the high prevalence of dental caries, and its consequences on people's health and quality of life, a recognizable conceptual view of caries as a NCD is required to target an effective management. Current understanding of dental caries supports prevention through acting on the modifiable risk factors (behaviors) and involves management based on an interdisciplinary approach. Communicating these modern concepts among researchers, clinicians and policymakers is needed to decrease the global high burden of the disease.

Hybrid nanocoatings of self-assembled organic-inorganic amphiphiles for prevention of implant infections.

Antimicrobial coatings are one of the most promising strategies to prevent bacterial infections in orthopedic and dental implants. Combining antimicrobial agents with different antimicrobial mechanisms might have synergistic effects and be more potent. Others have shown that nanocomposites of silver nanoparticles (AgNPs) decorated with antimicrobial peptides (AMPs) show increased potency as free agents in solution. However, similar nanocomposites have not been explored to coat biomaterials through cooperative weak electrostatic attraction forces between AMP, AgNPs and substrates in need of protection against infection. In this work, we synthesized self-assembled antimicrobial amphiphiles of an AMP, GL13K. Then, we decorated the AMP nanostructures with AgNPs, which were finally used to coat etched Ti (eTi) surfaces. The strong hydrogen bonding between the AMP amphiphiles and the polar eTi yielded a robust and stable coating. When compared to single AgNP or single AMP coatings, our hybrid nanocoatings had notably higher in vitro antimicrobial potency against multiple bacteria strains related to implant infection. The hybrid coating also showed relevant antimicrobial activity in an in vivo subcutaneous infection model in rats. This work advances the application of AgNP/AMP nanocomposites as effective coatings for prevention of implant infections. STATEMENT OF SIGNIFICANCE: High morbidity, mortality and elevated costs are associated with orthopedic and dental implant infections. Conventional antibiotic treatment is ineffective due to barrier-like extracellular polymeric substances in biofilms and the increasing threat from antibiotic resistance. Antimicrobial coatings are one of the most promising strategies, but the performance is usually unsatisfactory, especially when tested in vivo. Here, we present a hybrid nanocoating with different modes of action to prevent implant infections using self-assembled antimicrobial peptide (AMP) amphiphiles decorated with silver nanoparticles (AgNPs). When compared to single AgNP or AMP coatings, our hybrid nanocoatings showed significant increases in antimicrobial potency against multiple implant infection-related bacterial strains in vitro and in an in vivo rat subcutaneous infection model.

¿Cómo Intervenir el Proceso de Caries en Adultos? Adaptación del Consenso de ORCA/EFCD/DGZ / How to Intervene the Caries Process in Adults? Adaptation of the ORCA/EFCD/DGZ Consensus

RESUMEN: El manejo terapéutico de lesiones de caries primarias y secundarias concentra gran parte del quehacer de los dentistas en el mundo. Recientes cambios en la concepción de la enfermedad de caries llevaron a un panel de expertos de la Organización Europea para la Investigación en Caries (ORCA), la Federación Europea de Odontología Conservadora (EFCD) y la Federación Alemana de Odontología Conservadora (DGZ) a analizar la evidencia y consensuar recomendaciones sobre manejo de caries en adultos. Mediante una reunión en Berlín, Alemania en 2019 y con metodología e-Delphi, los expertos analizaron la evidencia y propusieron recomendaciones clínicas. El propósito de este artículo es presentar una adaptación idiomática de las principales recomendaciones, que incluyen terapias no invasivas (higiene, uso de fluoruros y control de dieta), terapias microinvasiva (sellantes e infiltrantes), terapias necesariamente invasivas y la reparación de restauraciones. Todas las recomendaciones se basan en un enfoque mínimamente invasivo, con un adecuado manejo restaurador. Los dentistas de países hispanoparlantes podrán encontrar recomendaciones basadas en evidencia, provenientes de un consenso de expertos a nivel global, que orienten sus decisiones clínicas, apoyándose en los principios de la odontología de mínima intervención.

ABSTRACT: Therapeutic management of primary and secondary caries lesions concentrates much of the work of dentists throughout the world. Recent changes in caries disease conception and therapeutic management led a panel of experts from the European Organisation for Caries Research (ORCA), the European Federation for Conservative Dentistry (EFCD) and the German Federation for Conservative Dentistry (DGZ) to analyze the evidence and reach consensus on recommendations for caries management in adults. Through a meeting held in Berlin, Germany in 2019 and using an e-Delphi methodology, the experts analyzed the evidence and proposed clinical recommendations. The purpose of this article is to present an idiomatic adaptation to Spanish of the main recommendations, which include non-invasive therapies (hygiene, use of fluoride and diet control), microinvasive therapies (sealants and infiltrants), invasive therapies and repair of restorations. All recommendations are based on a minimally invasive dentistry approach, with a technically adequate restorative management. Spanish-speaking dentists may use these consensus recommendations to guide their clinical decisions, based on the most recent evidence and experts opinions, under the principles of minimal intervention dentistry.

Physical-chemical interactions between dental materials surface, salivary pellicle and Streptococcus gordonii.

Dental materials are susceptible to dental plaque formation, which increases the risk of biofilm-associated oral diseases. Physical-chemical properties of dental material surfaces can affect salivary pellicle formation and bacteria attachment, but relationships between these properties have been understudied. We aimed to assess the effects of surface properties and adsorbed salivary pellicle on Streptococcus gordonii adhesion to traditional dental materials. Adsorption of salivary pellicle from one donor on gold, stainless steel, alumina and zirconia was monitored with a quartz crystal microbalance with dissipation monitoring (QCM-D). Surfaces were characterized by X-ray photoelectron spectroscopy, atomic force microscopy and water contact angles measurement before and after pellicle adsorption. Visualization and quantification of Live/Dead stained bacteria and scanning electron microscopy were used to study S. gordonii attachment to materials with and without pellicle. The work of adhesion between surfaces and bacteria was also determined. Adsorption kinetics and the final thickness of pellicle formed on the four materials were similar. Pellicle deposition on all materials increased surface hydrophilicity, surface energy and work of adhesion with bacteria. Surfaces with pellicle had significantly more attached bacteria than surfaces without pellicle, but the physical-chemical properties of the dental material did not significantly alter bacteria attachment. Our findings suggested that the critical factor increasing S. gordonii attachment was the salivary pellicle formed on dental materials. This is attributed to increased work of adhesion between bacteria and substrates with pellicle. New dental materials should be designed for controlling bacteria attachment by tuning thickness, composition and structure of the adsorbed salivary pellicle.