Novel Organic-Inorganic Nanocomposite Hybrids Based on Bioactive Glass Nanoparticles and Their Enhanced Osteoinductive Properties.

Inorganic-organic hybrid biomaterials have been proposed for bone tissue repair, with improved mechanical flexibility compared with scaffolds fabricated from bioceramics. However, obtaining hybrids with osteoinductive properties equivalent to those of bioceramics is still a challenge. In this work, we present for the first time the synthesis of a class II hybrid modified with bioactive glass nanoparticles (nBGs) with osteoinductive properties. The nanocomposite hybrids were produced by incorporating nBGs in situ into a polytetrahydrofuran (PTHF) and silica (SiO2) hybrid synthesis mixture using a combined sol-gel and cationic polymerization method. nBGs ~80 nm in size were synthesized using the sol-gel technique. The structure, composition, morphology, and mechanical properties of the resulting materials were characterized using ATR-FTIR, 29Si MAS NMR, SEM-EDX, AFM, TGA, DSC, mechanical, and DMA testing. The in vitro bioactivity and degradability of the hybrids were assessed in simulated body fluid (SBF) and PBS, respectively. Cytocompatibility with mesenchymal stem cells was assessed using MTS and cell adhesion assays. Osteogenic differentiation was determined using the alkaline phosphatase activity (ALP), as well as the gene expression of Runx2 and Osterix markers. Hybrids loaded with 5, 10, and 15% of nBGs retained the mechanical flexibility of the PTHF-SiO2 matrix and improved its ability to promote the formation of bone-like apatite in SBF. The nBGs did not impair cell viability, increased the ALP activity, and upregulated the expression of Runx2 and Osterix. These results demonstrate that nBGs are an effective osteoinductive nanoadditive for the production of class II hybrid materials with enhanced properties for bone tissue regeneration.

Influence of Topography and Composition of Commercial Titanium Dental Implants on Cell Adhesion of Human Gingiva-Derived Mesenchymal Stem Cells: An In Vitro Study.

The topography and composition of dental implant surfaces directly impact mesenchymal cell adhesion, proliferation, and differentiation, crucial aspects of achieving osseointegration. However, cell adhesion to biomaterials is considered a key step that drives cell proliferation and differentiation. The aim of this study was to characterize characterize the topography and composition of commercial titanium dental implants manufactured with different surface treatments (two sandblasted/acid-etched (SLA) (INNO Implants, Busan, Republic of Korea; BioHorizonsTM, Oceanside, CA, USA) and two calcium phosphate (CaP) treated (Biounite®, Berazategui, Argentina; Zimmer Biomet, Inc., Warsaw, IN, USA)) and to investigate their influence on the process of cell adhesion in vitro. A smooth surface implant (Zimmer Biomet, Inc.) was used as a control. For that, high-resolution methodologies such as scanning electron microscopy (SEM), X-ray dispersive spectroscopy (EDX), laser scanning confocal microscopy (LSCM), and atomic force microscopy (AFM) were employed. Protein adsorption and retromolar gingival mesenchymal stem cells (GMSCs) adhesion to the implant surfaces were evaluated after 48 h. The adherent cells were examined by SEM and LSCM for morphologic and quantitative analyses. ANOVA and Tukey tests (α = 0.05) were employed to determine statistical significance. SEM revealed that INNO, BioHorizonsTM, and Zimmer implants have an irregular surface, whereas Biounite® has a regular topography consisting of an ordered pattern. EDX confirmed a calcium and phosphate layer on the Biounite® and Zimmer surfaces, and AFM exhibited different roughness parameters. Protein adsorption and cell adhesion were detected on all the implant surfaces studied. However, the Biounite® implant with CaP and regular topography showed the highest protein adsorption capacity and density of adherent GMSCs. Although the Zimmer implant also had a CaP treatment, protein and cell adhesion levels were lower than those observed with Biounite®. Our findings indicated that the surface regularity of the implants is a more determinant factor in the cell adhesion process than the CaP treatment. A regular, nanostructured, hydrophilic, and moderately rough topography generates a higher protein adsorption capacity and thus promotes more efficient cell adhesion.

Tooth Loss and Caries Experience of Elderly Chileans in the Context of the COVID-19 Pandemic in Five Regions of Chile.

Risk factors associated with tooth loss have been studied; however, the current status of the epidemiological profiles and the impact of the pandemic on the oral health of the elderly is still unknown. This study aims to determine the experience of caries and tooth loss among elderly Chilean citizens in five regions and to identify the risk factors associated with tooth loss. The sample includes 135 participants over 60 years old assessed during COVID-19 lockdown. Sociodemographic variables such as education and RSH (Social Registry of Households) were obtained through a teledentistry platform called TEGO. The history of chronic diseases such as diabetes, obesity, depression and dental caries reported by DMFT index scores were incorporated. The statistical analysis included Adjusted Odds Ratios (ORs) to assess risk factors associated with the lack of functional dentition. Multivariate hypothesis testing was used to compare the mean equality of DMFT and its components between regions (p-value < 0.05). Individuals with RSH ≤ 40% were at higher risk of having no functional dentition with OR 4.56 (95% CI: 1.71, 12.17). The only mean difference between regions was the filled tooth component. Tooth loss was associated with multidimensional lower income, where the elderly belonging to the 40% most vulnerable population had a higher prevalence of non-functional dentition. This study highlights the importance of implementing a National Oral Health Policy that focuses on oral health promotion and minimally invasive dentistry for the most vulnerable population.

Tego: a new concept of teledentistry for the elderly through a web platform and mobile app in the context of the covid-19 pandemic / Tego: un nuevo concepto de teleodontología para adultos mayores a través de una plataforma web y aplicación móvil en el contexto de la pandemia del covid-19

Objective: To develop a new concept of teledentistry for the elderly through a web platform and associated mobile application in the context of the COVID-19 pandemic. Material and Methods: A new concept for attention via teledentistry of the elderly supported by the web platform/app TEGO (Acronym for Tele-platform of Geriatric and Dental Specialties in Spanish) was developed. Priority and urgent dental care for elderly patients in the context of the COVID-19 pandemic was provided onboard a mobile dental clinic equipped with all the necessary conventional dental care facilities as well as state-of-the-art digital technology. Dental care was carried out in five cities of Chile. For the study, 135 elderly patients were treated. The tele-dental care model includes visit-appointment and remote interconsultation with a staff of specialists. To evaluate patient satisfaction aspects, regarding the service / care provided, a user satisfaction survey was applied. Results: A total of 68 questionnaires were completed by patients. The results showed high levels of patients' satisfaction after the priority or urgent dental care, which reached above 75% in all dimensions of the questionnaire (Access to dental care, user treatment, platform, recommendation). Conclusion: The generation of a technological ecosystem for teledentistry can provide a series of important advantages in the attention of elderly patients, by optimizing the dental care coverage by different specialists who can provide attention to a population that has limited or no access to them.

Objetivo: Desarrollar un nuevo concepto de teleodon-tología para adultos mayores a través de una plataforma web y aplicación móvil asociada en el contexto de la pandemia de COVID-19. Material y Métodos: Se desarrolló un nuevo concepto de atención vía teleodontología del adulto mayor apoyado en la plataforma/app web TEGO (Teleplataforma de Especialidades Geriatricas y Odontológicas). La atención dental prioritaria y urgente para pacientes de edad avanzada en el contexto de la pandemia de COVID-19 se brindó a bordo de una clínica dental móvil equipada con todas las instalaciones de atención dental convencional necesarias, así como con tecnología digital de última generación. La atención odontológica se realizó en cinco ciudades de Chile. Para el estudio, 135 pacientes de edad avanzada fueron atendidos. El modelo de atención teledental incluye visita-cita e inter-consulta remota con un staff de especialistas. Para evaluar los aspectos de satisfacción del paciente, respecto al servicio/atención brindada, se aplicó una encuesta de satisfacción del usuario. Resultados: Los pacientes completaron un total de 68 cuestionarios. Los resultados mostraron altos niveles de satisfacción de los pacientes tras la atención odontológica prioritaria o urgente, que superó el 75% en todas las dimensiones del cuestionario (Acceso a la atención odontológica, trato al usuario, plataforma, recomendación). Conclusión: La generación de un ecosistema tecnológico para la teleodontología puede brindar una serie de ventajas importantes en la atención de pacientes adultos mayores, al optimizar la cobertura de atención odontológica por parte de diferentes especialistas que pueden brindar atención a una población que tiene acceso limitado o nulo.

Analysis of clinical indicators of teledentistry management for the elderly population during the covid-19 pandemic in Chile / Análisis de indicadores clínicos del manejo de la teleodontología para la población adulta mayor durante la pandemia del covid-19 en Chile

Objective: To analyze clinical indicators of teledentistry management for the elderly population during the COVID-19 pandemic in Chile. Material and Methods:A pilot teledentistry project was developed for dental care of the elderly in 5 regions of Chile. The data obtained were recorded on the TEGO Platform to be subsequently selected and analyzed by the researchers in terms of clinical management indicators: degree of installed occupancy, degree of available occupation, degree of real occupation, interconsultation indicator per patient attended, urgencies according to reason for consultations, unpostponable prosthetic treatment according to reason for consultations, prevention in relation to granted benefits, prevention in relation to the patients cared for, and project absenteeism indicator. Results: The clinical management indicators obtained were as follows: The average degree of installed occupancy was 67%. The average degree of available occupancy was 78%, which accounts for the clinical time in which there are dental chairs and dentists willing to work. The average real occupancy degree was 86%. The average interconsultation indicator per patient observed was 25%. The indicator of urgencies according to the reason for the consultation was 95%, which indicates that the purpose of the study was fulfilled. The average unpostponable prosthetic treatment according to the reason for consultations was 5%. The prevention in relation to granted benefits reached 39%. Finally, the average indicator of absenteeism was 17%. Conclusion: The measurement of clinical management indicators contributes to meet the Chilean Ministry of Health Explicit Health Guarantees (GES), which are: Access, Timely Attention, Quality and Financial Protection.

Objetivo: Analizar indicadores clínicos del manejo de la teleodontología para la población de adultos mayores durante la pandemia de COVID-19 en Chile. Material y Métodos: Se desarrolló un proyecto piloto de teleodontología para la atención odontológica del adulto mayor en cinco regiones de Chile. Los datos obtenidos fueron registrados en la plataforma TEGO para ser posteriormente seleccionados y analizados por los investigadores en cuanto a indicadores de gestión clínica: grado de ocupación instalada, grado de ocupación disponible, grado de ocupación real, indicador de interconsulta por paciente atendido, urgencias según motivo por consultas, tratamiento protésico improrrogable según motivo de consultas, prevención en relación a las prestaciones otorgadas, prevención en relación a los pacientes atendidos e indicador de ausentismo del proyecto. Resultados: Los indicadores de gestión clínica obtenidos fueron los siguientes: El grado medio de ocupación instalada fue del 67%. El grado medio de ocupación disponible fue del 78%, lo que da cuenta del tiempo clínico en el que hay sillones dentales y odontólogos dispuestos a trabajar. El grado de ocupación real promedio fue del 86%. El indicador medio de interconsultas por paciente observado fue del 25%. El indicador de urgencias según el motivo de la consulta fue del 95%, lo que indica que se cumplió con el propósito del estudio. El promedio de tratamientos protésicos impostergables según el motivo de consulta fue del 5%. La prevención en relación a las prestaciones otorgadas alcanzó el 39%. Finalmente, el indicador promedio de ausentismo fue de 17%. Conclusión: La medición de indicadores de gestión clínica contribuye a cumplir con las Garantías Explícitas en Salud (GES) del Ministerio de Salud de Chile, que son: Acceso, Oportunidad, Calidad y Protección Financiera.

Implementation of a Teledentistry Platform for Dental Emergencies for the Elderly in the Context of the COVID-19 Pandemic in Chile.

Objectives: To develop and implement a "semi-presential" technology platform to support urgent and priority dental care for the elderly in the context of the COVID-19 pandemic among the Chilean population. Methods: A dental mobile clinic was implemented along with the development of a technological platform designed to support emergency and priority dental procedures, including teleconsultation with specialists. Under strict biosafety protocols, dental care was provided in five Chilean regions between February and May 2021. Sociodemographic, medical, and dental data were recorded. Results: A total of 135 patients over sixty years old, with a mean age of 72 years, were treated, 48 males and 87 females were attended between February and May 2021 in five different regions of Chile. 53.3% required immediate or urgent treatment, and 24.4% were derived to specialists from whom 60.6% needed immediate or urgent treatment. 74.3% of teleconsultations were derived to an oral pathology specialist. Conclusion: It was shown that a "semi-presential" technology platform implemented in a mobile dental clinic can help elderly people who are impeded to look for traditional dental assistance during a pandemic.

Implant-Supported Maxillary and Mandibular Rehabilitation in a Patient With Hallermann-Streiff Syndrome.

ABSTRACT: Hallermann-Streiff syndrome is a rare congenital abnormality involving multiple craniofacial malformations, such as micrognathia, prominent frontal and nasal bones, vision defects, and dental anomalies. In most patients, patients affected with this disease have multiple dental problems involving a severe loss of teeth and maxillary atrophy. Specialized individual and multidisciplinary treatments are often required in these patients. The objective of this report was to demonstrate the rehabilitation approach of a patient with Hallermann-Streiff syndrome using total implant-support prostheses, with optimal aesthetic and functional results, which significantly improved the patient's quality of life.

In situ preparation and osteogenic properties of bionanocomposite scaffolds based on aliphatic polyurethane and bioactive glass nanoparticles.

Bionanocomposite scaffolds based on aliphatic polyurethane (PU) and bioactive glass nanoparticles were produced by using a one-step in situ polymerization method. Bioactive glass nanoparticles (nBG) or mesoporous BG nanospheres (nMBG) were incorporated during the polymerization reaction to produce simultaneous formation and foaming of porous nanocomposite scaffolds. The in vitro bioactivity of the scaffolds was assessed in simulated body fluid (SBF), and through cytocompatibility and osteogenic differentiation assays with stem cells. Bone regeneration properties of the scaffold materials were in vivo assessed by using a critical-sized femoral defect model in rat. The scaffold nanocomposites showed excellent cytocompatibility and ability to accelerate the crystallization of bone-like apatite in vitro. nBG/PU bionanocomposite scaffold exhibited the higher capacity to stimulate osteogenic cell differentiation as judged by an increased ALP activity and the presence of mineralized nodules associated with the stem cells. nBG (5%)/PU scaffold significantly also produces in vivo a denser and more significant amount of new bone after 8 weeks of implantation, which is attributed to the more rapid dissolution rate of nBG into osteogenic ionic products compared to nMBG. The results of this work show that the in situ polymerization method combined with the use of nanodimensional BG particles enable the production of PU - based scaffolds with enhanced bioactive properties to stimulate the bone tissue regeneration.

Bionanocomposite scaffolds based on chitosan-gelatin and nanodimensional bioactive glass particles: In vitro properties and in vivo bone regeneration.

Bone repair bionanocomposite scaffolds were produced by incorporating dense bioactive glass nanoparticles or mesoporous bioactive glass nanospheres into a chitosan-gelatin polymer blend. The in vitro bioactivity of the scaffolds was assessed in simulated body fluid, and cell viability and osteogenic differentiation assays were performed with dental pulp stem cells. Bone regeneration properties of the scaffold materials were in vivo assessed by using a critical-sized femoral defect model in rat. The scaffold nanocomposites showed excellent cytocompatibility and ability to accelerate the crystallization of bone-like apatite in vitro. Bionanocomposites prepared with bioactive glass nanoparticles were particularly more active to promote the osteogenic differentiation of dental pulp stem cells as judged by the higher activity of alkaline phosphatase. This result is attributed to the faster dissolution of bioactive glass nanoparticles into osteogenic ionic products compared to mesoporous bioactive glass nanospheres. In vivo experiments demonstrated that bioactive glass nanoparticles (5%)/chitosan-gelatin bionanocomposite significantly produces the highest amount of new bone (∼80%) in the defect area after eight weeks of implantation. The bone regeneration capacity exhibited by the scaffolds formulated with nanodimensional bioactive glass particles make them attractive for bone reconstruction applications.

Synthesis of new antibacterial composite coating for titanium based on highly ordered nanoporous silica and silver nanoparticles.

Infection is the most common factor that leads to dental titanium implant failure. Antibacterial implant surfaces based on nano-scale modifications of the titanium appear as an attractive strategy for control of peri-implantitis. In the present work, the preparation and antibacterial properties of a novel composite coating for titanium based on nanoporous silica and silver nanoparticles are presented. Starch-capped silver nanoparticles (AgNPs) were synthesized and then incorporated into sol-gel based solution system. The AgNP-doped nanoporous silica coatings were prepared on titanium surface using a combined sol-gel and evaporation-induced self-assembly (EISA) method. The coating nanostructure was characterized by XRD, SEM-EDX, and HR-TEM. Antibacterial activity was evaluated against Aggregatibacter actinomycetemcomitans, a representative pathogen of dental peri-implantitis. Colony-forming units (CFUs) were counted within the biofilm and at the planktonic state. Biofilm development was quantified using crystal violet staining and viability of adherent bacteria was confirmed with the Live/Dead fluorescence assay. Silica-based composite coating containing AgNPs (AgNP/NSC) was prepared on titanium surface by direct incorporation of AgNP suspension into the sol-gel system. The self-assembly technique enabled the spontaneous formation of a highly ordered nanoporosity in the coating structure, which is a desired property for osseointegration aspects of titanium implant surface. AgNP/NSC coating produces a strong antibacterial effect on titanium surface by not only killing the adherent bacteria but also reducing the extent of biofilm formation. Biofilm survival is reduced by more than 70% on the AgNP/NSC-modified titanium surface, compared to the control. This antibacterial effect was verified for up to 7 days of incubation. The long-term antibacterial activity exhibited by the nanostructured AgNP/NSC-titanium surface against A. actinomycetemcomitans suggests that this type of nano-scale surface modification is a promissory strategy to control infections associated with dental implant rehabilitation.

Synthesis of nanostructured porous silica coatings on titanium and their cell adhesive and osteogenic differentiation properties.

Nanostructured porous silica coatings were synthesized on titanium by the combined sol-gel and evaporation-induced self-assembly process. The silica-coating structures were characterized by X-ray diffraction, transmission electron microscopy, scanning electron microscopy, and nitrogen sorptometry. The effect of the nanoporous surface on apatite formation in simulated body fluid, protein adsorption, osteoblast cell adhesion behavior, and osteogenic differentiation of human bone marrow mesenchymal stem cells (hBMSCs) is reported. Silica coatings with highly ordered sub-10 nm porosity accelerate early osteoblast adhesive response, a favorable cell response that is attributed to an indirect effect due to the high protein adsorption observed on the large-specific surface area of the nanoporous coating but is also probably due to direct mechanical stimulus from the nanostructured topography. The nanoporous silica coatings, particularly those doped with calcium and phosphate, also promote the osteogenic differentiation of hBMSCs with spontaneous mineral nodule formation in basal conditions. The bioactive surface properties exhibited by the nanostructured porous silica coatings make these materials a promising alternative to improve the osseointegration properties of titanium dental implants and could have future impact on the nanoscale design of implant surfaces.