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1.
J Orthod ; 47(2): 116-128, 2020 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-32052682

RESUMEN

OBJECTIVE: To survey the opinion of recently qualified and established orthodontists on the perceived value of their training and to identify specific areas which which were considered to be deficient, adequately covered or focussed on excessively. DESIGN: Descriptive cross-sectional survey. SETTING: Online electronic questionnaire. PARTICIPANTS: Members of the British Orthodontic Society (BOS). METHODS: An electronic questionnaire was circulated to members of the BOS focusing on dental education history, and opinions concerning orthodontic teaching generally and specific clinical and non-clinical subjects. Information was also obtained in terms of possible need for improvement, modification or removal of teaching on focused academic and clinical aspects. RESULTS: A total of 217 responses were received from 1080 emailed invitations resulting in a response rate of 20.1%. Respondents were generally satisfied with their training both in relation to theoretical, academic and practical aspects. However, training was regarded as deficient by some respondents in respect of temporary anchorage devices (38%), bonded retainers (6%), experience with lingual appliances (47%), removable aligners (44%), inter-proximal reduction (24%) and adult orthodontics (16%), working with therapists (32%), and NHS contracts (47%) and commissioning (47%). CONCLUSION: The overall satisfaction of BOS members with postgraduate orthodontic training is generally high, although both recently qualified and established practitioners emphasised the need for better exposure to training in specific practical aspects and practice management within the NHS.


Asunto(s)
Ortodoncia , Sociedades Odontológicas , Estudios Transversales , Humanos , Ortodoncistas , Encuestas y Cuestionarios
2.
Infect Immun ; 86(5)2018 05.
Artículo en Inglés | MEDLINE | ID: mdl-29483293

RESUMEN

This study investigated the host response to a polymicrobial pulpal infection consisting of Streptococcus anginosus and Enterococcus faecalis, bacteria commonly implicated in dental abscesses and endodontic failure, using a validated ex vivo rat tooth model. Tooth slices were inoculated with planktonic cultures of S. anginosus or E. faecalis alone or in coculture at S. anginosus/E. faecalis ratios of 50:50 and 90:10. Attachment was semiquantified by measuring the area covered by fluorescently labeled bacteria. Host response was established by viable histological cell counts, and inflammatory response was measured using reverse transcription-quantitative PCR (RT-qPCR) and immunohistochemistry. A significant reduction in cell viability was observed for single and polymicrobial infections, with no significant differences between infection types (∼2,000 cells/mm2 for infected pulps compared to ∼4,000 cells/mm2 for uninfected pulps). E. faecalis demonstrated significantly higher levels of attachment (6.5%) than S. anginosus alone (2.3%) and mixed-species infections (3.4% for 50:50 and 2.3% for 90:10), with a remarkable affinity for the pulpal vasculature. Infections with E. faecalis demonstrated the greatest increase in tumor necrosis factor alpha (TNF-α) (47.1-fold for E. faecalis, 14.6-fold for S. anginosus, 60.1-fold for 50:50, and 25.0-fold for 90:10) and interleukin 1ß (IL-1ß) expression (54.8-fold for E. faecalis, 8.8-fold for S. anginosus, 54.5-fold for 50:50, and 39.9-fold for 90:10) compared to uninfected samples. Immunohistochemistry confirmed this, with the majority of inflammation localized to the pulpal vasculature and odontoblast regions. Interestingly, E. faecalis supernatant and heat-killed E. faecalis treatments were unable to induce the same inflammatory response, suggesting E. faecalis pathogenicity in pulpitis is linked to its greater ability to attach to the pulpal vasculature.


Asunto(s)
Coinfección/patología , Enterococcus faecalis/patogenicidad , Interacciones Huésped-Parásitos , Pulpitis/microbiología , Pulpitis/fisiopatología , Ratas/microbiología , Streptococcus anginosus/patogenicidad , Animales , Modelos Animales
3.
Mov Disord ; 33(8): 1306-1314, 2018 08.
Artículo en Inglés | MEDLINE | ID: mdl-30098269

RESUMEN

BACKGROUND: Preliminary evidence suggests that diet manipulation may influence motor and nonmotor symptoms in PD, but conflict exists regarding the ideal fat to carbohydrate ratio. OBJECTIVES: We designed a pilot randomized, controlled trial to compare the plausibility, safety, and efficacy of a low-fat, high-carbohydrate diet versus a ketogenic diet in a hospital clinic of PD patients. METHODS: We developed a protocol to support PD patients in a diet study and randomly assigned patients to a low-fat or ketogenic diet. Primary outcomes were within- and between-group changes in MDS-UPDRS Parts 1 to 4 over 8 weeks. RESULTS: We randomized 47 patients, of which 44 commenced the diets and 38 completed the study (86% completion rate for patients commencing the diets). The ketogenic diet group maintained physiological ketosis. Both groups significantly decreased their MDS-UPDRS scores, but the ketogenic group decreased more in Part 1 (-4.58 ± 2.17 points, representing a 41% improvement in baseline Part 1 scores) compared to the low-fat group (-0.99 ± 3.63 points, representing an 11% improvement) (P < 0.001), with the largest between-group decreases observed for urinary problems, pain and other sensations, fatigue, daytime sleepiness, and cognitive impairment. There were no between-group differences in the magnitude of decrease for Parts 2 to 4. The most common adverse effects were excessive hunger in the low-fat group and intermittent exacerbation of the PD tremor and/or rigidity in the ketogenic group. CONCLUSIONS: It is plausible and safe for PD patients to maintain a low-fat or ketogenic diet for 8 weeks. Both diet groups significantly improved in motor and nonmotor symptoms; however, the ketogenic group showed greater improvements in nonmotor symptoms. © 2018 The Authors. Movement Disorders published by Wiley Periodicals, Inc. on behalf of International Parkinson and Movement Disorder Society.


Asunto(s)
Dieta con Restricción de Grasas/métodos , Dieta Cetogénica/métodos , Enfermedad de Parkinson/dietoterapia , Adulto , Anciano , Glucemia/metabolismo , Femenino , Estudios de Seguimiento , Humanos , Cetonas/sangre , Masculino , Persona de Mediana Edad , Pruebas Neuropsicológicas , Evaluación de Resultado en la Atención de Salud , Proyectos Piloto , Índice de Severidad de la Enfermedad
4.
Am J Dent ; 31(3): 155-165, 2018 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-30028935

RESUMEN

PURPOSE: To evaluate if mechanical and thermal cycling promote remineralization at the resin-dentin interface after bonding with three different adhesive approaches. METHODS: Dentin surfaces were subjected to three different treatments: demineralization (1) by 37% phosphoric acid followed by application of an etch-and-rinse dentin adhesive Single Bond (Adper Single Bond) (SB); (2) by 0.5 M ethylenediaminetetraacetic acid (EDTA) followed by SB; (3) application of a self-etch dentin adhesive: Clearfil-SEB (Clearfil SE Bond). Bonded interfaces were stored during 24 hours and then submitted for 3 months to: (1) storage at 37ºC, (2) load cycling, (3) thermocycling, and (4) thermo+load cycling. One section was extracted from each tooth, monthly. Resin-dentin interfaces were analyzed by AFM nano-indentation, Raman spectroscopy/cluster analysis and Masson's trichrome staining at 24 hours, 1, 2 and 3 months, to determine remineralization at the interface. RESULTS: Thermo+load cycling promoted the highest biomimetic remineralization at the hybrid layer formed with EDTA+SB and Clearfil-SEB, at the 1 month time point. A narrow mineral-depleted zone was observed after thermo+load cycling with EDTA+ SB, and at those specimens bonded with Clearfil-SEB. Thermo+load cycling remineralized the dentin interface treated with EDTA+SB and Clearfil-SEB, after 1 month of study period, providing bioactivity and maturity of formed minerals. CLINICAL SIGNIFICANCE: In vitro challenging (thermo+load cycling) favors dentin remineralization at the resin-dentin bonded interfaces promoted with mild conditioning acids.


Asunto(s)
Recubrimiento Dental Adhesivo , Cementos Dentales , Remineralización Dental , Dentina , Recubrimientos Dentinarios , Ácido Edético , Ensayo de Materiales , Cementos de Resina , Resistencia a la Tracción
5.
Int J Mol Sci ; 19(11)2018 Nov 02.
Artículo en Inglés | MEDLINE | ID: mdl-30400188

RESUMEN

Cariogenic oral biofilms cause recurrent dental caries around composite restorations, resulting in unprosperous oral health and expensive restorative treatment. Quaternary ammonium monomers that can be copolymerized with dental resin systems have been explored for the modulation of dental plaque biofilm growth over dental composite surfaces. Here, for the first time, we investigated the effect of bis(2-methacryloyloxyethyl) dimethylammonium bromide (QADM) on human overlying mature oral biofilms grown intra-orally in human participants for 7⁻14 days. Seventeen volunteers wore palatal devices containing composite specimens containing 10% by mass of QADM or a control composite without QADM. After 7 and 14 days, the adherent biofilms were collected to determine bacterial counts via colony-forming unit (CFU) counts. Biofilm viability, chronological changes, and percentage coverage were also determined through live/dead staining. QADM composites caused a significant inhibition of Streptococcus mutans biofilm formation for up to seven days. No difference in the CFU values were found for the 14-day period. Our findings suggest that: (1) QADM composites were successful in inhibiting 1⁻3-day biofilms in the oral environment in vivo; (2) QADM significantly reduced the portion of the S. mutans group; and (3) stronger antibiofilm activity is required for the control of mature long-term cariogenic biofilms. Contact-killing strategies using dental materials aimed at preventing or at least reducing high numbers of cariogenic bacteria seem to be a promising approach in patients at high risk of the recurrence of dental caries around composites.


Asunto(s)
Biopelículas/efectos de los fármacos , Bromuros/farmacología , Caries Dental/microbiología , Materiales Dentales/farmacología , Metacrilatos/farmacología , Compuestos de Amonio Cuaternario/farmacología , Adulto , Biopelículas/crecimiento & desarrollo , Bromuros/química , Recuento de Colonia Microbiana , Materiales Dentales/química , Femenino , Humanos , Masculino , Metacrilatos/química , Viabilidad Microbiana/efectos de los fármacos , Compuestos de Amonio Cuaternario/química , Streptococcus mutans/efectos de los fármacos , Adulto Joven
7.
J Esthet Restor Dent ; 27(4): 203-12, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25988796

RESUMEN

PURPOSE: This study aimed to assess the reliability of the preoperative occlusal matrix technique in terms of the surface Vickers microhardness (VMH) of the underlying composite restorative material. MATERIALS AND METHODS: Two hundred microhybrid composite cylinders were built up and light-cured in a single-layer step, forming two experimental groups (N = 100) according to their heights (1.5 mm/2 mm). Each group was divided into five subgroups (N = 20) depending on the matrix thickness (no matrix/0.5 mm/1 mm/2 mm/3 mm). Half the specimens per subgroup (N = 10) were randomly polymerized with a quartz-tungsten-halogen (QTH) light-curing unit (LCU). The remaining half were cured using a light-emitting diode lamp. The top and bottom samples' sides were tested for VMH at 1 hour and 24 hours post-curing using a universal VMH machine. A multiple analysis of variance with repeated measurements for the "surface" factor and the Student-Newman-Keuls test were run (α = 0.05). Bottom/top microhardness ratios were compared with the empirically accepted limit (0.8). Surface topography was analyzed under a scanning electron microscope. RESULTS: The thinnest matrices provided the significantly best VMH values. LCU, disc height, and time also contributed to VMH. At 24 hours, 2-mm high discs polymerized with QTH resulted in inadequate microhardness ratios when 1-mm thick to 3-mm thick matrices were used. CONCLUSION: The thinnest matrices are the most recommendable ones. CLINICAL SIGNIFICANCE: The esthetics and occlusal reproducibility achieved with customized occlusal matrices fabricated before cavity preparation have been widely demonstrated. However, their effect on the physical properties of the restorations deserves further investigation. Although more studies are necessary, the thinnest matrices seem to be the most suitable to preserve the composite surface VMH and the curing depth.


Asunto(s)
Resinas Compuestas , Luces de Curación Dental , Pruebas de Dureza , Humanos , Microscopía Electrónica de Rastreo , Polimerizacion , Periodo Preoperatorio , Propiedades de Superficie
8.
Dent Mater ; 40(3): 393-406, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38114343

RESUMEN

OBJECTIVES: Tideglusib has shown great performance in terms of dentin regenerative properties. This study aims to evaluate bonding ability, of demineralized dentin infiltrated with polymeric nanoparticles (NPs) doped with tideglusib (TG) (TG-NPs). METHODS: Dentin conditioned surfaces were infiltrated with NPs and TG-NPs. Bonded interfaces were created and stored for 24 h and then submitted to mechanical, chemical and thermal challenging. The resin-dentin interface was evaluated through a doubled dye fluorescent technique and a calcium chelator fluorophore under a confocal laser scanning microscopy, and by field emission scanning electron microscopy. RESULTS: Dentin surfaces treated with TG-NPs and load cycled produced higher bond strength than the rest of the groups. Immersion of dentin specimens treated with undoped-NPs in collagenase solution attained the lowest microtensile bond strength (MTBS) values. Both porosity and nanoleakage decreased when dentin was infiltrated with TG-NPs, that revealed strong signals of xylenol orange stain at both hybrid layer and dentinal tubules. The presence of NPs, in general, inducted the presence of mineralized interfaces after mechanical loading and thermocycling. CONCLUSIONS: Nanoparticles doped with tideglusib promoted the highest dentin bonding efficacy among groups, as they facilitated the maximum bond strength values with creation of mineral deposits at the hybrid layer and dentinal walls. Tideglusib enabled scarce porosity, nanoleakage and advanced sealing among dentin groups. SIGNIFICANCE: Doping hydrophilic polymeric NPs with tideglusib, infiltrated in etched dentin represents a reproducible technique to create reparative dentin at the resin-dentin interface, by inducing therapeutic bioactivity.


Asunto(s)
Recubrimiento Dental Adhesivo , Cementos Dentales , Tiadiazoles , Cementos Dentales/química , Cementos de Resina/química , Glucógeno Sintasa Quinasa 3/análisis , Recubrimientos Dentinarios/química , Resistencia a la Tracción , Dentina/química , Microscopía Electrónica de Rastreo , Ensayo de Materiales
9.
J Neurosci ; 32(34): 11574-85, 2012 Aug 22.
Artículo en Inglés | MEDLINE | ID: mdl-22915102

RESUMEN

The mechanism by which extracellular cues influence intracellular biochemical cascades that guide axons is important, yet poorly understood. Because of the mechanical nature of axon extension, we explored whether the physical interactions of growth cones with their guidance cues might be involved. In the context of mouse spinal commissural neuron axon attraction to netrin-1, we found that mechanical attachment of netrin-1 to the substrate was required for axon outgrowth, growth cone expansion, axon attraction and phosphorylation of focal adhesion kinase (FAK) and Crk-associated substrate (CAS). Myosin II activity was necessary for traction forces >30 pN on netrin-1. Interestingly, while these myosin II-dependent forces on netrin-1 substrates or beads were needed to increase the kinase activity and phosphorylation of FAK, they were not necessary for netrin-1 to increase CAS phosphorylation. When FAK kinase activity was inhibited, the growth cone's ability to recruit additional adhesions and to generate forces >60 pN on netrin-1 was disrupted. Together, these findings demonstrate an important role for mechanotransduction during chemoattraction to netrin-1 and that mechanical activation of FAK reinforces interactions with netrin-1 allowing greater forces to be exerted.


Asunto(s)
Axones/fisiología , Proteína-Tirosina Quinasas de Adhesión Focal/metabolismo , Mecanotransducción Celular/fisiología , Factores de Crecimiento Nervioso/metabolismo , Neuronas/fisiología , Proteínas Supresoras de Tumor/metabolismo , Actinas/metabolismo , Animales , Axones/efectos de los fármacos , Línea Celular Transformada , Proteína Sustrato Asociada a CrK/genética , Proteína Sustrato Asociada a CrK/metabolismo , Electroporación , Embrión de Mamíferos , Inhibidores Enzimáticos/farmacología , Ensayo de Inmunoadsorción Enzimática , Femenino , Proteína-Tirosina Quinasas de Adhesión Focal/genética , Conos de Crecimiento/fisiología , Heparina/farmacología , Humanos , Proteínas Luminiscentes/genética , Masculino , Mecanotransducción Celular/efectos de los fármacos , Ratones , Miosina Tipo II/metabolismo , Factores de Crecimiento Nervioso/química , Factores de Crecimiento Nervioso/genética , Netrina-1 , Neuronas/citología , Neuronas/efectos de los fármacos , Técnicas de Cultivo de Órganos , Fosfoproteínas/metabolismo , Estimulación Física , Unión Proteica/genética , Estructura Terciaria de Proteína/genética , Estructura Terciaria de Proteína/fisiología , Transporte de Proteínas/genética , Quinolonas/farmacología , Médula Espinal/citología , Sulfonas/farmacología , Transfección , Proteínas Supresoras de Tumor/química , Proteínas Supresoras de Tumor/genética , Tirosina/metabolismo
10.
J Dent ; 132: 104470, 2023 05.
Artículo en Inglés | MEDLINE | ID: mdl-36842624

RESUMEN

OBJECTIVES: To compare the fracture resistance (FR) of three combinations of materials for full-arch maxillary implant-supported hybrid prostheses (HPs) with short cantilevers (≤ 10 mm). METHODS: Maxillary HPs were fabricated and classified as follows (n = 5 each): Group-1 (CC-A, control): acrylic-resin-veneered Co-Cr frameworks; Group-2 (CF-A): acrylic-resin-veneered carbon-fiber mesostructures; and Group-3 (CF-R): composite-resin-veneered carbon-fiber frames. Specimens were thermal-cycled (5,000 cycles; 5 °C-55 °C; dwell time: 30 s). Vertical loads were applied until failure, first at the 10-mm-long cantilever (LC), and, afterwards, at the anterior region (AR), using a universal testing machine (crosshead speed: 0.05 mm/s). The fracture pattern was assessed by stereomicroscope and SEM. The one-way ANOVA, the Bonferroni, and the independent samples t tests, were run (α= 0.05). RESULTS: At LC, CF-A, and CC-A samples exhibited the highest FR values (p< 0.001), showing no differences to each other. At AR, CC-A specimens recorded the highest FR, followed by CF-A samples (p< 0.001). CF-R HPs displayed the lowest FR at both locations (p< 0.001). The only group with differences between the tested sites was the CC-A, the AR being more resistant (p< 0.001). Most CC-A and CF-A HPs failed cohesively. CF-R prostheses mainly failed adhesively. CONCLUSIONS: Maxillary HPs with short cantilevers (≤ 10 mm) made of Co-Cr or carbon-fiber veneered with acrylic resin demonstrated an adequate mechanical resistance (> 900 N). CLINICAL SIGNIFICANCE: For maxillary HPs with cantilevers up to 10 mm, acrylic-veneered carbon- fiber mesostructures may be recommended, whereas coating carbon-fiber frames with composite resin seems not suitable.


Asunto(s)
Implantes Dentales , Prótesis Dental de Soporte Implantado , Resinas Acrílicas/química , Resinas Compuestas/química , Ensayo de Materiales
11.
J Dent ; 135: 104589, 2023 08.
Artículo en Inglés | MEDLINE | ID: mdl-37336355

RESUMEN

OBJECTIVES: To systematically assess aspects of teaching of posterior composite restorations (PCRs) in permanent teeth in dental schools. STUDY SELECTION: Quantitative studies reporting on dental schools' teaching regarding the placement of PCRs in permanent teeth. Random-effects meta-analyses and meta-regressions were performed. Risk of bias was assessed based on the Medical Education Research Study Quality Instrument (MERSQI). SOURCES: Electronic databases (MEDLINE via PubMed, EMBASE via Ovid, Web of Science, and Scopus) were searched in January 2023. DATA: Forty sources reporting on 34 studies having surveyed 1,286 dental schools were included. Overall, 92.7% (95%-CI: 88.2-95.5) of dental schools reported to teach PCRs. PCRs in three-surface Class II cavities are taught by 82.0% (95%-CI: 70.4-89.7). The mandatory use of liners in deep cavities is taught by 78.3% (95%-CI: 68.9-85.5), and 44.0% (95%-CI: 34.3-54.2) reported to teach bulk-fill composites. While most posterior restorations placed by students were composites (56.1%; 95%-CI: 46.0-65.8), 94.7% (95%-CI: 86.6-98.0) of dental schools (still) teach posterior amalgam restorations. The proportion of dental schools teaching PCRs in three-surface Class II cavities increased and the mean proportion of PCRs among all posterior restorations increased over time (padj.≤0.003). CONCLUSIONS: The teaching of PCRs in dental schools around the world reflects the increased use of resin composite in clinical practice, with students in countries where dental amalgam continues to be used, placing more posterior composites than restorations of dental amalgam. The teaching of PCRs, which is anticipated to increase, will continue to be refined with further developments in adhesive materials, devices, instrumentation, and techniques. CLINICAL SIGNIFICANCE: Graduating dentists can be expected to be familiar with the use of resin composites for the restoration of posterior teeth.


Asunto(s)
Caries Dental , Restauración Dental Permanente , Humanos , Restauración Dental Permanente/métodos , Amalgama Dental , Preparación de la Cavidad Dental/métodos , Resinas Compuestas , Caries Dental/terapia , Estudiantes , Enseñanza
12.
J Dent ; 138: 104690, 2023 11.
Artículo en Inglés | MEDLINE | ID: mdl-37666466

RESUMEN

BACKGROUND: Vascularization plays an important role in dental and craniofacial regenerations. Human periodontal ligament stem cells (hPDLSCs) are a promising cell source and, when co-cultured with human umbilical vein endothelial cells (hUVECs), could promote vascularization. The objectives of this study were to develop a novel prevascularized hPDLSC-hUVEC-calcium phosphate construct, and investigate the osteogenic and angiogenic efficacy of this construct with human platelet lysate (hPL) in cranial defects in rats for the first time. METHODS: hPDLSCs and hUVECs were co-cultured on calcium phosphate cement (CPC) scaffolds with hPL. Cell proliferation, angiogenic gene expression, angiogenesis, alkaline phosphatase activity, and cell-synthesized minerals were determined. Bone and vascular regenerations were investigated in rat critical-sized cranial defects in vivo. RESULTS: hPDLSC-hUVEC-CPC-hPL group had 2-fold greater angiogenic expressions and cell-synthesized mineral synthesis than hPDLSC-hUVEC-CPC group (p < 0.05). Microcapillary-like structures were formed on scaffolds in vitro. hPDLSC-hUVEC-CPC-hPL group had more vessels than hPDLSC-hUVEC-CPC group (p < 0.05). In cranial defects in rats, hPDLSC-hUVEC-CPC-hPL group regenerated new bone amount that was 2.1 folds and 4.0 folds, respectively, that of hPDLSC-hUVEC-CPC group and CPC control (p < 0.05). New blood vessel density of hPDLSC-hUVEC-CPC-hPL group was 2 folds and 7.9 folds, respectively, that of hPDLSC-hUVEC-CPC group and CPC control (p < 0.05). CONCLUSION: The hPL pre-culture method is promising to enhance bone regeneration via prevascularized CPC. Novel hPDLSC-hUVEC-CPC-hPL prevascularized construct increased new bone formation and blood vessel density by 4-8 folds over CPC control. CLINICAL SIGNIFICANCE: Novel hPDLSC-hUVEC-hPL-CPC prevascularized construct greatly increased bone and vascular regeneration in vivo and hence is promising for a wide range of craniofacial applications.


Asunto(s)
Ligamento Periodontal , Andamios del Tejido , Humanos , Animales , Ratas , Ratas Desnudas , Andamios del Tejido/química , Células Madre , Osteogénesis , Regeneración Ósea , Células Endoteliales de la Vena Umbilical Humana , Fosfatos de Calcio/farmacología , Fosfatos de Calcio/química , Cráneo/cirugía , Diferenciación Celular , Células Cultivadas
13.
Dent Mater ; 39(1): 41-56, 2023 01.
Artículo en Inglés | MEDLINE | ID: mdl-36460577

RESUMEN

OBJECTIVE: To investigate the effect of novel polymeric nanoparticles (NPs) doped with dexamethasone (Dex) on viscoelasticity, crystallinity and ultra-nanostructure of the formed hydroxyapatite after NPs dentin infiltration. METHODS: Undoped-NPs, Dex-doped NPs (Dex-NPs) and zinc-doped-Dex-NPs (Zn-Dex-NPs) were tested at dentin, after 24 h and 21 d. A control group without NPs was included. Coronal dentin surfaces were studied by nano-dynamic mechanical analysis measurements, atomic force microscopy, X-ray diffraction and transmission electron microscopy. Mean and standard deviation were analyzed by ANOVA and Student-Newman-Keuls multiple comparisons (p < 0.05). RESULTS: At 21 d of storage time, both groups doped with Dex exhibited the highest complex, storage and loss moduli among groups. Zn-Dex-NPs and Dex-NPs promoted the highest and lowest tan delta values, respectively. Dex-NPs contributed to increase the fibril diameters of dentin collagen over time. Dentin surfaces treated with Zn-Dex-NPs attained the lowest nano-roughness values, provoked the highest crystallinity, and produced the longest and shortest crystallite and grain size. These new crystals organized with randomly oriented lattices. Dex-NPs induced the highest microstrain. Crystalline and amorphous matter was present in the mineral precipitates of all groups, but Zn and Dex loaded NPs helped to increase crystallinity. SIGNIFICANCE: Dentin treated with Zn-Dex-NPs improved crystallographic and atomic order, providing structural stability, high mechanical performance and tissue maturation. Amorphous content was also present, so high hydroxyapatite solubility, bioactivity and remineralizing activity due to the high ion-rich environment took place in the infiltrated dentin.


Asunto(s)
Nanopartículas , Remineralización Dental , Zinc , Humanos , Dentina/química , Dexametasona/farmacología , Dexametasona/análisis , Durapatita/farmacología , Nanopartículas/química , Polímeros , Zinc/farmacología
14.
Polymers (Basel) ; 15(7)2023 Mar 30.
Artículo en Inglés | MEDLINE | ID: mdl-37050340

RESUMEN

The main target of bone tissue engineering is to design biomaterials that support bone regeneration and vascularization. Nanostructured membranes of (MMA)1-co-(HEMA)1/(MA)3-co-(HEA)2 loaded with 5% wt of SiO2-nanoparticles (Si-M) were doped with zinc (Zn-Si-M) or doxycycline (Dox-Si-M). Critical bone defects were effectuated on six New Zealand-bred rabbit skulls and then they were covered with the membranes. After six weeks, a histological analysis (toluidine blue technique) was employed to determine bone cell population as osteoblasts, osteoclasts, osteocytes, M1 and M2 macrophages and vasculature. Membranes covering the bone defect determined a higher count of bone cells and blood vessels than in the sham group at the top regions of the defect. Pro-inflammatory M1 appeared in a higher number in the top regions than in the bottom regions, when Si-M and Dox-Si-M were used. Samples treated with Dox-Si-M showed a higher amount of anti-inflammatory and pro-regenerative M2 macrophages. The M1/M2 ratio obtained its lowest value in the absence of membranes. On the top regions, osteoblasts were more abundant when using Si-M and Zn-Si-M. Osteoclasts were equally distributed at the central and lateral regions. The sham group and samples treated with Zn-Si-M attained a higher number of osteocytes at the top regions. A preferential osteoconductive, osteoinductive and angiogenic clinical environment was created in the vicinity of the membrane placed on critical bone defects.

15.
J Dent ; 130: 104410, 2023 03.
Artículo en Inglés | MEDLINE | ID: mdl-36626975

RESUMEN

OBJECTIVES: The aim was to investigate aspects of the teaching of restoration repair as a minimally invasive alternative to replacing defective direct composite restorations in undergraduate curricula teaching programs in Brazilian dental schools. METHODS: A 14-item validated survey questionnaire was mailed to directors/coordinators of operative/restorative dentistry teachers of Brazilian Dental Schools. Data were collected on demographic characteristics of the teachers and institutions, together with questions on the teaching of the repair of defective resin-based composite restorations as part of the school curriculum; the rationale behind the teaching; the nature of the teaching (preclinical and/or clinical); how techniques were taught, indications for repair, operative techniques, materials used, patient acceptability and expected longevity of completed repairs. RESULTS: Two hundred and twenty-two (94%) directors/ coordinators of dental curricula in Brazil were contacted. One hundred and thirty-one directors/coordinators (59%) replied, providing the e-mail address from the teacher responsible for the operative/restorative dentistry program in their school. Of these, 104 responded to the questionnaire (79% response rate). Ninety-three (89%) of the participating schools reported teaching composite repairs as an alternative to replacing restorations. Of the theoretical content, 43% was taught at preclinical and clinical levels, whereas most practical experience (53%) was acquired at clinical levels. Eighty-eight schools (95%) reported tooth substance preservation being the main reason for teaching repair techniques. All schools that taught repairs reported high patient acceptability. CONCLUSIONS: The teaching of composite restoration repair as an alternative to restoration replacement is established in undergraduate programs in most of the Brazilian dental schools surveyed. CLINICAL SIGNIFICANCE: The reasons for teaching restoration repair in Brazil were found to be quite unanimous among teachers, especially regarding the preservation of tooth structure. Variations were found in the clinical indications for repair, suggesting the need for further investigations. Monitoring repaired restorations should be encouraged and could contribute to future studies.


Asunto(s)
Reparación de Restauración Dental , Restauración Dental Permanente , Humanos , Restauración Dental Permanente/métodos , Brasil , Resinas Compuestas/química , Fracaso de la Restauración Dental , Facultades de Odontología , Operatoria Dental/educación , Reparación de Restauración Dental/métodos , Curriculum , Encuestas y Cuestionarios , Enseñanza
16.
Dent Update ; 39(2): 118-20, 122-6, 2012 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-22482269

RESUMEN

UNLABELLED: Removable partial dentures (RPDs) remain a mainstay of prosthodontic care for partially dentate patients. Appropriately designed, they can restore masticatory efficiency, improve aesthetics and speech, and help secure overall oral health. However, challenges remain in providing such treatments, including maintaining adequate plaque control, achieving adequate retention, and facilitating patient tolerance. The aim of this paper is to review the successful provision of RPDs. CLINICAL RELEVANCE: Removable partial dentures are a successful form of treatment for replacing missing teeth, and can be successfully provided with appropriate design and fabrication concepts in mind.


Asunto(s)
Diseño de Dentadura , Retención de Dentadura , Dentadura Parcial Removible , Arcada Parcialmente Edéntula/rehabilitación , Adaptación Psicológica , Protocolos Clínicos , Placa Dental/prevención & control , Humanos , Higiene Bucal , Tecnología Odontológica/legislación & jurisprudencia
17.
J Dent ; 120: 104099, 2022 05.
Artículo en Inglés | MEDLINE | ID: mdl-35337899

RESUMEN

Assessing when dental trainees are ready to independently undertake clinical procedures at specialist level is critical for dental postgraduate programmes to determine when a trainee is 'work ready', in addition to ensuring patient safety. Entrustable professional activities (EPA) are a novel method of competency-based assessment. An EPA is a unit of professional practice or critical clinical activity identified within dental training programmes, which should be assessed during training, to establish if trainees are ready for independent practice, with a progressive decrease in supervision, based on supervisors' entrustment decisions. This article describes EPAs, entrustment decisions, including entrustment supervision scales and the process recommended to develop EPAs within dental curricula. EPAs have not been formally introduced for assessment within dental education programmes in the United Kingdom, but recent developments have been described in undergraduate dental education globally. Clinical significance: Competency-based assessments need to be continually developed to adapt to rapidly changing population health care and dental needs, to determine when dental trainees are ready for independent clinical practice. Early development of entrustable professional activities for assessment in undergraduate dental programmes has been well received by both trainees and supervisors. Further investigation is required to consider formal development of EPAs within postgraduate dental programmes.


Asunto(s)
Educación Basada en Competencias , Internado y Residencia , Competencia Clínica , Educación Basada en Competencias/métodos , Curriculum , Humanos , Estudiantes , Reino Unido
18.
J Dent ; 123: 104207, 2022 08.
Artículo en Inglés | MEDLINE | ID: mdl-35760208

RESUMEN

OBJECTIVES: To achieve consensus amongst an expert panel of prosthodontics/restorative dentistry academics on the best undergraduate teaching and assessments, and to develop recommendations regarding teaching and assessment of undergraduate prosthodontics. METHODS: Semi-structured electronic questionnaires were used to collect data from senior clinical academics involved in the teaching of prosthodontics on three consecutive occasions (Delphi method). The questionnaires asked the experts' opinion on best teaching and assessment methods in the undergraduate prosthodontics curriculum. Invitation emails, with a hyperlink to the Round 1 questionnaire, were sent to 36 international dental academic experts. In later rounds, panellists were invited to consider their previous responses in light of the overall group response in attempt to bring the panel to a consensus. The group response was summarized using simple descriptive statistics, and the target level of consensus for each question was set at ≥ 70%. A response rate of at least 70% between rounds was deemed appropriate to maintain rigour. RESULTS: Twenty-three senior academic experts from eleven countries agreed to participate. Eighteen (representing nine different countries) completed the questionnaires in its entirety (response rate 78.3%). The number of statements that attained consensus agreement was much higher than the number of non-consensus statements-92.6%, 175 statements out of 189 over three iterative rounds. Only 14 statements did not obtain a consensus during this Delphi study. CONCLUSIONS: A total of 175 consensus statements represent the agreement expert views of participated senior academics in prosthodontics from nine different countries and across four continents. These consensus statements could be considered detailed guidelines and recommendations to improve future undergraduates' curriculum in prosthodontics. CLINICAL SIGNIFICANCE: This Delphi study achieved a high consensus among a panel of senior academics in the teaching and assessment of undergraduate prosthodontics. This consensus could help minimise the current international and national divergence in dental schools' prosthodontics curricula, which could benefit future dentists and, subsequently, the patients.


Asunto(s)
Curriculum , Prostodoncia , Consenso , Humanos , Estudiantes , Encuestas y Cuestionarios , Enseñanza
19.
J Dent ; 117: 103887, 2022 02.
Artículo en Inglés | MEDLINE | ID: mdl-34762987

RESUMEN

OBJECTIVES: This research aimed to compare the oral health-related quality of life (OHRQoL) between fully dentate subjects and edentulous patients wearing implant-supported fixed partial dentures (i-FPDs). The clinical conditions of both types of restorations were evaluated. METHODS: Participants were assigned to: Group-1 (SR, n = 50): screw-retained i-FPD wearers; Group-2 (CR, n = 50): cement-retained i-FPD wearers; and Group-3 (ND, n = 50): dentate subjects with a healthy natural dentition (controls). Patients answered the OHIP-14sp and QoLIP-10 questionnaires. Data related to sociodemographics, prosthesis features, peri­implant status, complications, and subjective evaluations, were compiled. Potential modulators of the OHRQoL and the i-FPDs' clinical conditions were assessed using non-parametric tests (α= 0.05). RESULTS: ND individuals were the least satisfied (OHIP-14sp; p< 0.001). Both prosthodontic groups reported similar levels of wellbeing, excluding the speaking difficulties, which were lower for SR wearers as shown by both scales (p = 0.001). The most discontented patients (OHIP-14sp) were: women (p = 0.022), under 65 years (p = 0.03), without partner (p< 0.001) and having a crown (p = 0.033). The level of education/schooling also affected the OHIP-14sp scores (p< 0.001). Implant mobility and peri­implantitis were more frequent among CR wearers (p-values= 0.008 and 0.05, respectively). CONCLUSIONS: The OHRQoL of both prosthodontic groups was comparably higher than that of the dentate subjects, who were the most nonconformist. The self-perceived satisfaction was mainly modulated by sociodemographic factors. CLINICAL SIGNIFICANCE: Overall, the retention system did not impact the OHRQoL, prosthetic problems, and subjective evaluations of i-FPD wearers. However, the cementation may increase the risk of peri­implant diseases.


Asunto(s)
Prótesis de Recubrimiento , Calidad de Vida , Tornillos Óseos , Estudios Transversales , Prótesis Dental de Soporte Implantado , Femenino , Humanos , Salud Bucal , Satisfacción del Paciente
20.
J Dent ; 116: 103902, 2022 01.
Artículo en Inglés | MEDLINE | ID: mdl-34822914

RESUMEN

OBJECTIVES: This in vitro study aimed to find the best combination of mesostructure and veneering materials for full-arch implant-supported hybrid prostheses (HPs) in terms of the fracture resistance (FR) of their cantilevers. METHODS: Three groups (n = 5 each) of maxillary HPs were fabricated: Group-1 (CC-A, control): Co-Cr frameworks coated with acrylic resin; Group-2 (CF-A): carbon fiber veneered with acrylic resin; and Group-3 (CF-R): carbon fiber coated with composite resin. All specimens were submitted to 5,000 thermal cycles (5 °C - 55 °C, dwell time: 30 s), and subjected to a single cantilever bending test in a universal testing machine (crosshead speed: 0.5 mm/min) until failure. The fracture pattern was assessed using stereo microscope and SEM. The one-way ANOVA and Bonferroni tests were run (α= 0.05). RESULTS: The FR yielded significant differences among the three groups (p< 0.001). CC-A samples reached the highest FR values (p ≤ 0.001), whereas both CF-A and CF-R HPs exhibited the comparably (p = 0.107) lowest FR. CC-A specimens failed cohesively (100%): mostly without chipping (80%). CF-A mesostructures were always broken at the connections of the distal implants. CF-R prostheses often failed adhesively (80%). CONCLUSIONS: The HPs made of Co-Cr veneered with acrylic demonstrated the best mechanical behavior, being the only group whose 13-mm long cantilevers exceeded the clinically acceptable FR of 900 N. The HPs constructed with carbon fiber frameworks showed, additionally, more unfavorable fracture patterns. CLINICAL SIGNIFICANCE: For HPs with cantilevers up to 13 mm, Co-Cr mesostructures coated with acrylic may represent the optimum combination of materials.


Asunto(s)
Implantes Dentales , Prótesis Dental de Soporte Implantado , Resinas Acrílicas , Fibra de Carbono , Coronas con Frente Estético , Ensayo de Materiales
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