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1.
Mater Sci Eng C Mater Biol Appl ; 123: 112000, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33812620

RESUMEN

The use of dental implants is growing rapidly for the last few decades and Ti-based dental implants are a commonly used prosthetic structure in dentistry. Recently, the combined effect of corrosion and wear, called tribocorrosion, is considered as a major driving process in the early failure of dental implants. However, no previous study has reported the prediction of tribocorrosion processes in advance. Therefore, this study is a novel investigation on how the acoustic emission (AE) technique can predict tribocorrosion processes in commercially-pure titanium (cpTi) and titanium-zirconium (TiZr) alloys. In this study, tribocorrosion tests were performed under potentiostatic conditions and AE detection system associated with it captures AE data. Current evolution and friction coefficient data obtained from the potentiostatic evaluations were compared with AE absolute energy showcased the same data interpretation of tribocorrosion characteristics. Other AE data such as duration, count, and amplitude, matched more closely with other potentiostatic corrosion evaluations and delivered more promising results in the detection of tribocorrosion. Hence, AE can be consider as a tool for predicting tribocorrosion in dental implants. Experimental results also reveal Ti5Zr as one of the most appropriate dental implant materials while exposing Ti10Zr's lower effectiveness to withstand in the simulated oral environment.

2.
Acta Biomater ; 2020 Nov 21.
Artículo en Inglés | MEDLINE | ID: mdl-33227485

RESUMEN

Surface functionalization is an effective approach to improve and enhance the properties of dental materials. A review of atomic layer deposition (ALD) in the field of dental materials is presented. ALD is a well-established thin film deposition technique. It is being used for surface functionalization in different technologies and biological related applications. With film thickness control down to Ångström length scale and uniform conformal thin films even on complex 3D substrates, high quality thin films and their reproducibility are noteworthy advantages of ALD over other thin film deposition methods. Low temperature ALD allows temperature sensitive substrates to be functionalized with high quality ultra-thin films too. In the current work, ALD is elaborated as a promising method for surface modification of dental materials. Different aspects of conventional dental materials that can be enhanced using ALD are discussed. Also, the influence of different ALD thin films and their microstructure on the surface properties, corrosion-resistance, antibacterial activity, biofilm formation, and osteoblast compatibility are addressed. Depending on the stage of advancement for the studied materials reported in the literature, these studies are then categorized into four stages: fabrication & characterization, in vitro studies, in vivo studies, and human tests. Materials coated with ALD thin films with potential dental applications are also presented here and they are categorized as stage 1. The purpose of this review is to organize and present the up to date ALD research on dental materials. The current study can serve as a guide for future work on using ALD for surface functionalization and resulting property tuning of materials in real world dental applications.

4.
Sci Adv ; 6(47)2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-33208378

RESUMEN

To treat impairments in hard tissues or overcome pathological calcification in soft tissues, a detailed understanding of mineralization pathways of calcium phosphate materials is needed. Here, we report a detailed mechanistic study of hydroxyapatite (HA) mineralization pathways in an artificial saliva solution via in situ liquid cell transmission electron microscopy (TEM). It is found that the mineralization of HA starts by forming ion-rich and ion-poor solutions in the saliva solution, followed by coexistence of the classical and nonclassical nucleation processes. For the nonclassical path, amorphous calcium phosphate (ACP) functions as the substrate for HA nucleation on the ACP surface, while the classical path features direct HA nucleation from the solution. The growth of HA crystals on the surface of ACP is accompanied by the ACP dissolution process. The discoveries reported in this work are important to understand the physiological and pathological formation of HA minerals, as well as to engineer the biomineralization process for bone healing and hard tissue repairs.

5.
Materials (Basel) ; 13(18)2020 Sep 04.
Artículo en Inglés | MEDLINE | ID: mdl-32899725

RESUMEN

Magnesium (Mg) alloys have received attention in the literature as potential biomaterials for use as absorbable implants in oral and maxillofacial and orthopedic surgery applications. This study aimed to evaluate the available clinical studies related to patients who underwent bone fixation (patients), and received conventional fixation (intervention), in comparison to absorbable metals (comparison), in terms of follow-up and complications (outcomes). A systematic review and meta-analysis were performed in accordance with the PRISMA statement and PROSPERO (CRD42020188654), PICO question, ROBINS-I, and ROB scales. The relative risk (RR) of complications and failures were calculated considering a confidence interval (CI) of 95%. Eight studies (three randomized clinical trial (RCT), one retrospective studies, two case-control studies, and two prospective studies) involving 468 patients, including 230 Mg screws and 213 Titanium (Ti) screws, were analyzed. The meta-analysis did not show any significant differences when comparing the use of Mg and Ti screws for complications (p = 0.868). The estimated complication rate was 13.3% (95% CI: 8.3% to 20.6%) for the comparison group who received an absorbable Mg screw. The use of absorbable metals is feasible for clinical applications in bone surgery with equivalent outcomes to standard metal fixation devices.

6.
ACS Appl Mater Interfaces ; 12(39): 44371-44380, 2020 Sep 30.
Artículo en Inglés | MEDLINE | ID: mdl-32886478

RESUMEN

In modern biomaterial-based electronics, conductive and flexible biomaterials are gaining increasing attention for their wide range of applications in biomedical and wearable electronics industries. The ecofriendly, biodegradable, and self-resorbable nature of these materials makes them an excellent choice in fabricating green and transient electronics. Surface functionalization of these biomaterials is required to cater to the need of designing electronics based on these substrate materials. In this work, a low-temperature atomic layer deposition (ALD) process of platinum (Pt) is presented to deposit a conductive thin film on collagen biomaterials, for the first time. Surface characterization revealed that a very thin ALD-deposited seed layer of TiO2 on the collagen surface prior to Pt deposition is an alternative for achieving a better nucleation and 100% surface coverage of ultrathin Pt on collagen surfaces. The presence of a pure metallic Pt thin film was confirmed from surface chemical characterization. Electrical characterization proved the existence of a continuous and conductive Pt thin film (∼27.8 ± 1.4 nm) on collagen with a resistivity of 295 ± 30 µΩ cm, which occurred because of the virtue of TiO2. Analysis of its electronic structures showed that the presence of metastable state due to the presence of TiO2 enables electrons to easily flow from valence into conductive bands. As a result, this turned collagen into a flexible conductive biomaterial.

7.
J Prosthodont ; 2020 Sep 16.
Artículo en Inglés | MEDLINE | ID: mdl-32935894

RESUMEN

PURPOSE: The accuracy of digital impressions is still controversial for complete arch implant cases. The aim of this study is to compare the accuracy of different intraoral scanners with the conventional technique in terms of trueness and precision in a complete arch implant model. MATERIAL AND METHODS: Eight implants were inserted asymmetrically in a polyurethane edentulous mandibular model with different angulations. A 3-dimensional (3D) reference model was obtained by scanning this polyurethane model with an optical scanner. First, digital impressions were made by using 3 different intraoral scanners: Carestream 3500 (DC), Cerec Omnicam (DO) and 3Shape Trios 3 (DT). Subsequently, a nonsplinted open tray impression technique was used for conventional impression group (C) and then the master casts were digitalized with a lab scanner. Each 10 STL files belonging to 4 different impression groups were imported to a reverse engineering program, to measure distance and angle deviations from the reference model. All statistical analyses were performed after taking absolute values of the data. After comparing the impression groups with one-way ANOVA, the trueness and precision values were analyzed by Tukey post hoc test and 0.05 was used as the level of significance. RESULTS: The mean trueness of distance was 123.06 ± 89.83 µm for DC, 229.72 ± 121.34 µm for DO, 209.75 ± 47.07 µm for DT, and 345.32 ± 75.12 µm for C group (p < 0.0001). While DC showed significantly lower deviation compared to DO and C, no significant difference was found between DC and DT. C showed the highest distance deviation significantly in all groups; and no significant difference was found between DO and DT groups. In angle measurements; the trueness was 0.26° ± 0.07° for DC, 0.53° ± 0.42° for DO, 0.33° ± 0.30° for DT, and 0.74° ± 0.65° for C group. There was no significant difference between the groups in terms of angular trueness (p = 0.074). In terms of the precision for distance, the results of DC 80.43 ± 29.69 µm, DO 94.06 ± 69.96 µm, DT 35.55 ± 28.46 µm and C 66.97 ± 36.69 µm were determined (p = 0.036). The significant difference was found only between DT and DO among all groups. Finally, angular precision was determined to be 0.19° ± 0.11° for DC, 0.30° ± 0.28° for DO, 0.22° ± 0.19° for DT, and 0.50° ± 0.38° for Group C. No significant difference was found between the groups, in terms of angular precision (p = 0.053). CONCLUSIONS: All digital impression groups yielded superior data compared to conventional technique in terms of trueness. DC formed the impression group with the highest trueness in both distance and angular measurements. The results of this in vitro study suggest the use of intraoral scanners compared to the conventional impression techniques in complete arch implant cases with high angulations.

8.
J Prosthodont ; 29(8): 656-659, 2020 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-32406074

RESUMEN

PURPOSE: To assess the management of sleep apnea and snoring disorders in Advanced Education Programs in Prosthodontics (AEPP) in the United States. MATERIALS AND METHODS: A 51 item, online survey was sent to program directors at 48 AEPPs in the United States in 2015. Data results were analyzed descriptively. RESULTS: Thirty-five program directors responded to the survey. Twenty-four (68.6%, N = 35) programs report not having a dedicated course for the treatment of sleep apnea and snoring disorders. The majority (94.3%) of programs chose to treat sleep disordered breathing with oral appliance therapy and 80.0% (N = 35) of programs utilize customized sleep apnea oral devices. However, only 48.6% (N = 35) and 51.4% (N = 35) of programs regularly address sleep apnea and snoring disorders at initial examination during the comprehensive exam and medical history questionnaire, respectively. CONCLUSIONS: The confidence interval for this survey is 8.71 at a confidence level of 95% due to a response rate of 72.9%. This confidence interval suggests there is responder bias in the survey results. Therefore, the results of this survey provide a suggestion of how sleep disorders are managed in AEPPs. Programs appear to be consistent among each other with regards to treatment modalities for sleep disordered breathing. The results suggest that patients are not screened enough to receive treatment addressing sleep disorders.


Asunto(s)
Síndromes de la Apnea del Sueño , Ronquido , Curriculum , Humanos , Prostodoncia , Síndromes de la Apnea del Sueño/terapia , Ronquido/terapia , Encuestas y Cuestionarios , Estados Unidos
9.
J Prosthodont ; 29(5): 374-377, 2020 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-32133716

RESUMEN

PURPOSE: The purpose of this study was to obtain information about the resident selection and Match process that occurred for the Commission on Dental Accreditation (CODA)-accredited Advanced Education in Prosthodontics program in North America from the program directors' perspective, after the first year of implementation. MATERIALS AND METHODS: The list of Advanced Education in Prosthodontics program in CODA-accredited North American institutions was obtained from the ACP central office, and the directors of each program were identified. The surveys were distributed to 48 program directors online and results were compiled. RESULTS: Out of 48 programs, 43 directors responded to and completed the survey (90.0%), where 35 programs participated in the Match process, 5 did not, and 3 were omitted due to incomplete surveys. While the majority of programs did not see any changes in their applicant pool or their quality, 10 programs (25.0%) observed a number of increases in the application and 13 programs (32.5%) observed an increase in the quality of the applications. Among the 35 programs that participated in the Match process, the main reasons for their participation were "fairness" (48.2%), "did not want to keep moving up interview dates" (23.2%), and "have applicants come to interview as planned" (21.4%). Thirty-three programs reported that 75% to 100% of the invited applicants came to the interview (76.7%). The majority of programs that participated in Match expressed satisfaction with the process (29/33, 80.6%). Sixteen programs (45.7%) reported that they matched with 100% of their first selections. CONCLUSION: Overall response of reintroduction of the Match process for advanced prosthodontic resident selection was very positive for majority of the program directors.


Asunto(s)
Internado y Residencia , Prostodoncia , América del Norte , Satisfacción Personal , Encuestas y Cuestionarios , Estados Unidos
10.
Arch Oral Biol ; 111: 104643, 2020 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-31918345

RESUMEN

AIM: To evaluate the cytotoxicity and inflammatory response of different types of provisional restorative materials to mice gingival fibroblasts. METHODS: Cytotoxicity of provisional material discs (thermal-polymerized acrylic resin; auto-polymerized acrylic resin; bisacrylic resin; nano-ceramic resin for CAD/CAM and prefabricated polymer block for CAD/CAM) to Mice (Balb/c) gingival cell were investigated under direct and indirect contact (extracts) at 24, 48 and 72 h, using the MTT and Alamar blue assays. Materials extracts (24 h) were applied to the cell culture (indirect contact) or cells were seeded on discs of provisional materials, and the cytotoxicity and production of IL-6, IL-1ß and TNF-α after 24, 48 and 72 h were analyzed through MTT, Alamar Blue® and ELISA. Culture medium was used as control for indirect contact assay (extract) and the surfaces of the wells without discs of provisional materials were used as control for direct contact assay. Results were analysed statistically by ANOVA followed by the Bonferroni-Test correction. Statistically significant differences were considered if P was < .05. RESULTS: Auto-polymerized and bisacrylic resins (direct contact) reduced cell viability after 24, 48 and 72 h compared to control (P < .05). Indirect contact (extract) was not cytotoxic to cells at all periods compared to control (P > .05). Auto-polymerized and bisacrylic resins increased IL-6, IL-1ß and TNF-α levels mainly at 24 h when compared to the other materials (P < .001). CONCLUSION: Auto-polymerized and bisacrylic were more cytotoxic to mice gingival fibroblasts. CAD/CAM nano ceramic resin and prefabricated polymer blocks are more predictable materials to preserve the periodontal soft tissues.


Asunto(s)
Resinas Acrílicas , Materiales Dentales , Animales , Cerámica , Resinas Compuestas , Diseño Asistido por Computadora , Ensayo de Materiales , Ratones , Propiedades de Superficie
11.
J Esthet Restor Dent ; 32(1): 73-80, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31709728

RESUMEN

OBJECTIVE: To evaluate the long-term color stainability, translucency, and contrast ratio (CR) of different resins used to fabricate interim prostheses after immersion in acidic/staining solutions. MATERIALS AND METHODS: A total of 160 specimens were divided into 16 groups (n = 10) according to the material (heat-polymerized acrylic resin [HPAR], auto-polymerized acrylic resin [APR], nanoparticulated bis-acrylic resin [BR], and prefabricated poly(methyl methacrylate) block for CAD/CAM [CADR]) and immersion solutions (artificial saliva, cola beverage, coffee, and red wine). A spectrophotometer was used before and after each immersion period (7, 14, 28, 90, and 180 days). Color differences (CIEDE2000 and CIELab) were calculated. A three-way repeated-measures analysis of variance and Bonferroni test (α = .05) were used. RESULTS: After 180 days, the APR presented the highest value for coffee and the CADR presented the smallest value for the cola (P < .001). For the CR, the highest values were obtained at 180 days for BR in coffee (1.35) and wine (1.18) (P < .001). Higher translucency parameters were obtained in the BR and CADR in the initial, 14, 28, and 90 days (P < .001). CONCLUSIONS: From the greatest to the smallest staining potential, the solutions were classified as: wine > coffee > cola beverage > saliva, while for the materials as: APR > BR > HPAR > CADR. CLINICAL SIGNIFICANCE: The knowledge of the long-term optical behavior of interim prosthetic materials is important for clinicians to decide which material to use to match the dietary intake of their patients and their esthetic demands. Prefabricated blocks for CAD/CAM systems have been shown to maintaining their optical characteristics even after a long period of immersion in acidic/staining solutions.


Asunto(s)
Resinas Acrílicas , Materiales Dentales , Color , Resinas Compuestas , Humanos , Ensayo de Materiales , Coloración y Etiquetado , Propiedades de Superficie
12.
J Dent Educ ; 83(8): 887-894, 2019 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-31085685

RESUMEN

The aim of this study was to analyze information about advanced education programs in prosthodontics (AEPPs) collected in American Dental Association (ADA) surveys on advanced dental education from 2006-07 to 2016-17. Data recorded included number of AEPPs and information on program directors, applicants, and enrollees in AEPPs. The results showed that, from 2006 to 2016, there was an increase in the number of AEPPs and enrollment of prosthodontic residents, and the number of applicants per program more than doubled. Despite these increases, steps are needed to increase the number of underrepresented minority residents in prosthodontics. Also, a periodic survey of prosthodontic residents to identify their goals, experiences during training, and career plans could benefit the specialty by providing more insight into the future prosthodontic workforce.


Asunto(s)
Educación de Posgrado en Odontología/estadística & datos numéricos , Educación en Odontología , Evaluación de Programas y Proyectos de Salud , Prostodoncia/educación , Prostodoncia/estadística & datos numéricos , Actitud del Personal de Salud , Odontólogos , Educación en Odontología/economía , Educación en Odontología/estadística & datos numéricos , Humanos , Salud Bucal/educación , Evaluación de Programas y Proyectos de Salud/economía , Evaluación de Programas y Proyectos de Salud/estadística & datos numéricos , Estudios Retrospectivos , Facultades de Odontología , Encuestas y Cuestionarios , Estados Unidos
13.
J Prosthodont ; 28(9): 1011-1017, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-30720223

RESUMEN

PURPOSE: The objective of this study was to improve the surface characteristics of poly (methyl methacrylate) (PMMA) by developing a novel, thin film coating process and to characterize the resulting coated surface. MATERIALS AND METHODS: An atomic layer deposition (ALD) technique was developed to deposit a titanium dioxide (TiO2 ) nano-thin film on PMMA. The surface wettability for both coated and uncoated PMMA was determined by measuring water contact angle. Wear resistance was assessed using a mechanical tooth-brushing device with a 50 g load for 6000 strokes after 5 months of water storage. A denture cleanser challenge test was performed by using sonication in 3.8% sodium perborate for 1 hour with aged specimens. X-ray photoelectron spectroscopy (XPS) was used before and after the brushing test and challenge test to analyze the PMMA surface chemical composition. The mechanical strength of coated and uncoated PMMA was measured using a three-point bending test. Surface microbial interactions were also evaluated by assessing Candida albicans biofilm attachment. RESULTS: Nano-TiO2 coating (30 nm thick) was successfully deposited on PMMA at 65°C. After coating, water contact angle decreased from 70° to less than 5°. After brushing test, the coating remained intact. XPS analysis revealed no loss of TiO2 from coated specimens following brushing and denture cleanser sonication for 1 hour. There was no statistically significant difference in mechanical strength (MPa) (mean ± SD) between PMMA (139.4 ± 11.3) and TiO2 -PMMA (160.7 ± 37.1) (p = 0.0995). C. albicans attachment decreased by 63% to 77% on the coated PMMA surface. CONCLUSIONS: ALD is a promising technique to modify surface properties of PMMA and resulted in a stable adherent thin film. By depositing a TiO2 coating, PMMA surface properties may lead to significantly reduced microorganism adhesion and easier pathogen removal from PMMA. For patients who wear dentures, reducing the oral microbial biofilm burden using a TiO2 -coated PMMA surface could positively impact their oral and systemic health.


Asunto(s)
Polimetil Metacrilato , Titanio , Limpiadores de Dentadura , Humanos , Ensayo de Materiales , Propiedades de Superficie
14.
J Prosthet Dent ; 121(3): 538-543, 2019 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-30503151

RESUMEN

STATEMENT OF PROBLEM: Maxillofacial prostheses made of silicone elastomers undergo undesirable color degradation over time. How this color change can be prevented is unclear. PURPOSE: The purpose of this in vitro study was to evaluate the ability of an oxide nanocoating to prevent color degradation of maxillofacial silicone elastomers after artificial accelerated aging. MATERIAL AND METHODS: A silicone elastomer with functional intrinsic pigment was tested. Specimens (N=20) were fabricated, and half of them were coated with a nanolayer of titanium dioxide (TiO2) using atomic layer deposition. Both coated and noncoated specimens (control) were exposed to artificial aging at 450 kJ/m2 of total energy. Changes in the color of all the specimens with and without TiO2 nanocoating were measured before and after the atomic layer deposition coating and before and after aging. The obtained color data were analyzed by using independent t tests and the 1-sample t test (α=.05). RESULTS: Color change (ΔE1=3.4 ±1.4) was observed for the silicone elastomers after the specimens were surface coated with TiO2 nanofilm, although this change was not statistically significant (P=.369) compared with the acceptability threshold (ΔE=3.0). Upon exposure to artificial aging, the noncoated control specimens underwent color change (ΔE2=2.5 ±0.7, P=.083 compared with the acceptability threshold). The specimens with TiO2 nanocoated surface experienced the least color change (ΔE3=1.4 ±0.6) when subjected to artificial aging, and this change was significantly lower (P<.001) than the established acceptability threshold of ΔE=3.0. In addition, the chemical analyses confirmed that the TiO2 nanocoating remained on the surface after exposure to artificial aging. CONCLUSIONS: TiO2 nanocoating was shown to be effective in reducing color degradation of the silicone elastomer exposed to artificial aging for 120 hours with 450 kJ/m2 of total energy.


Asunto(s)
Prótesis Maxilofacial , Coloración de Prótesis , Color , Ensayo de Materiales , Óxidos , Elastómeros de Silicona
15.
J Prosthodont ; 28(2): e510-e518, 2019 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-29508487

RESUMEN

PURPOSE: In the field of prosthodontics, patients often require complex and extensive restorative care. This can involve the use of dental restorations to restore teeth on both the maxillary and mandibular arch. Current literature has evaluated the wear properties of different dental ceramics against enamel, but studies regarding dental ceramics opposing one another are limited. The purpose of this study was to assess the wear potential and wear behavior of CAD/CAM zirconia (ZR) and lithium disilicate (LD) materials against a similar ceramic material, and how the surface finish of these dental ceramics might affect patterns of wear. MATERIALS AND METHODS: Using a sphere-on-plate tribometer system, different surface finishes (glazed-G and glazed then polished-GP) of ZR and LD were evaluated following wear simulation. Artificial saliva of physiologic pH was used as a lubricant during wear simulation at 37°C. The coefficient of friction (COF) was calculated during the wear simulation. After wear simulation was complete, volume loss, surface roughness, and surface characterization of the specimens were analyzed using white-light interferometry and scanning electron microscopy (SEM). Statistical significance between materials and surface finish was established with two-way ANOVA and Bonferroni post hoc test (α = 0.05). RESULTS: Based on the 2-way ANOVA, material (p = 0.002) significantly affected the COF. LD showed a higher COF (p = 0.002) than ZR. Material (p < 0.001) and surface finish (p = 0.004) significantly affected the surface roughness inside the scar. ZR had significantly lower surface roughness compared to LD (p < 0.001). For outside scar, surface finish (p < 0.001) significantly affected the surface roughness. Polished specimens showed significantly higher roughness compared to glazed specimens for both inside (p = 0.004) and outside scar (p < 0.001). For volume loss, material (p < 0.001) and the interaction between material and surface finish (p < 0.001) were statistically significant. LD had higher volume loss than ZR (p < 0.001). For both glazed and polished finished, LD-G and LD-GP had significantly higher volume loss than ZR-G (p = 0.028), and ZR-GP (p < 0.001), respectively. SEM analysis indicated particle build-up and a grooving mechanism of wear for the LD-GP specimens. This suggested a three-body wear phenomenon occurring for LD-GP specimens, which was not visible in SEM imaging for other specimen types. CONCLUSIONS: This study demonstrated the resistance to wear and low abrasiveness of ZR when compared to LD in a simulated masticatory environment. This can be best explained by the increased strength of ZR, and the introduction of three-body wear to LD specimens from the accumulation of embedded wear debris onto its surface. Wear data and comparison of SEM images following wear simulation confirmed this interpretation.


Asunto(s)
Cerámica/química , Diseño Asistido por Computadora , Fracaso de la Restauración Dental , Porcelana Dental , Ensayo de Materiales , Microscopía Electrónica de Rastreo , Saliva Artificial/química , Propiedades de Superficie , Circonio
16.
J Dent Educ ; 82(12): 1320-1326, 2018 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-30504470

RESUMEN

The aims of this study were to measure the research productivity of directors of U.S. advanced education in prosthodontics programs (AEPP) and to identify associations between the directors' publication metrics and professional characteristics. A list of AEPP directors was obtained from the American College of Prosthodontists website in December 2015. Information on gender, academic rank, and highest degree was collected from the institutional website for each individual. Citation databases (Scopus and Google Scholar) were searched for each director's h-index and i10-index (both indexes are based on numbers of citations of the author's articles) and total numbers of publications and citations. The search identified 50 AEPP directors. The majority were male and had a primary appointment at a university. Most held the rank of associate professor or professor and held both DDS and MS degrees. The mean h-index and i10-index of all directors were 6.32±6.97 and 6.84±10.77, respectively. Their mean numbers of publications and citations were 24.60±31.21 and 288.40±625.97, respectively. The analysis showed that the program directors affiliated with a university had significantly higher mean values for all indexes than those of non-university-affiliated program directors. Professors had productivity metrics significantly higher than those of other ranks in all measures of research productivity.


Asunto(s)
Investigación Dental/estadística & datos numéricos , Docentes Médicos/estadística & datos numéricos , Prostodoncia/educación , Bibliometría , Femenino , Humanos , Masculino , Prostodoncia/estadística & datos numéricos , Estados Unidos
17.
J Dent Educ ; 82(12): 1335-1342, 2018 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-30504472

RESUMEN

Maxillofacial prosthetics (MFP) programs in the U.S. select only a limited number of applicants for fellowship positions. The aims of this study were to survey MFP fellows about which factors influenced their choice of programs and to survey MFP directors about what they considered critical factors in the selection process. Surveys were sent to all eight directors and 13 fellows at all eight U.S. MFP programs in June 2015. The directors' questions asked about general information, resident selection process, letters of recommendation, interview process, and decision process. The fellows' questions addressed their demographics, program-related factors, and future goals. The directors' surveys were sent directly to the directors, and the fellows' surveys were sent to the directors for distribution. The survey response rate for the directors was 87.5% (N=7), and that of the fellows was 53.8% (N=7). In selecting fellows for programs, responding directors reported the interview process was most important, followed by letters of recommendation, personal statement, and prosthodontic program grades. Responding fellows reported that location, variety of treatment, patient volume provided, and clinical education were crucial components in their choice of program. This information may be useful to MFP programs and fellows in the continuing development of this specialty.


Asunto(s)
Implantación de Prótesis Maxilofacial/educación , Prótesis Maxilofacial , Facultades de Odontología , Curriculum , Educación en Odontología/organización & administración , Humanos , Criterios de Admisión Escolar/estadística & datos numéricos , Facultades de Odontología/organización & administración , Encuestas y Cuestionarios , Estados Unidos
18.
ACS Appl Mater Interfaces ; 10(40): 34443-34454, 2018 Oct 10.
Artículo en Inglés | MEDLINE | ID: mdl-30212175

RESUMEN

Surface modifications of a biomaterial like collagen are crucial in improving the surface properties and thus enhancing the functionality and performance of such a material for a variety of biomedical applications. In this study, a commercially available collagen membrane's surface was functionalized by depositing an ultrathin film of titania or titanium dioxide (TiO2) using a room temperature atomic layer deposition (ALD) process. A novel titanium precursor-oxidizer combination was used for this process in a custom-made ALD reactor. Surface characterizations revealed successful deposition of uniform, conformal TiO2 thin film on the collagen fibrillar surface, and consequently, the fibers became thicker making the membrane pores smaller. The in vitro bioactivity of the ALD-TiO2 thin film coated collagen was investigated for the first time using cell proliferation and a calcium phosphate mineralization assay. The TiO2-coated collagen demonstrated improved biocompatibility promoting higher growth and proliferation of human osteoblastic and mesenchymal stem cells when compared to that of noncoated collagen. A higher level of calcium phosphate or apatite formation was observed on ALD modified collagen surface as compared to that on noncoated collagen. Therefore, this novel material can be promising in bone tissue engineering applications.


Asunto(s)
Materiales Biocompatibles Revestidos , Colágeno , Ensayo de Materiales , Membranas Artificiales , Células Madre Mesenquimatosas/metabolismo , Osteoblastos/metabolismo , Titanio , Línea Celular , Materiales Biocompatibles Revestidos/química , Materiales Biocompatibles Revestidos/farmacología , Colágeno/química , Colágeno/farmacología , Humanos , Células Madre Mesenquimatosas/citología , Osteoblastos/citología , Titanio/química , Titanio/farmacología
19.
J Oral Maxillofac Surg ; 76(10): 2074-2080, 2018 10.
Artículo en Inglés | MEDLINE | ID: mdl-29772190

RESUMEN

PURPOSE: The aim of this pilot study was to assay metal concentrations in the serum of patients who had undergone dental implant placement, orthognathic surgery using rigid metal fixation plates and screws, and total temporomandibular joint replacement (TMJ TJR). MATERIALS AND METHODS: Thirty patients were identified and included in this pilot study. Sixteen patients (9 men and 8 women), with an average age of 44 years (range, 19 to 79 yr), provided informed consent to participate and were divided into 3 study groups with 4 patients in each (group 1, orthognathic surgery; group 2, TMJ TJR; and group 3, dental implant placement). A control group consisted of volunteers without any implanted metallic devices. Blood samples for serum metal analysis were obtained and analyzed in accordance with the standardized collection and testing protocols used at the Trace Metal Analysis Laboratory of the Department of Orthopedic Surgery at the Rush University Medical Center (Chicago, IL). RESULTS: All control participants had levels below the normal reference range for all serum markers assessed. In the orthognathic group, 1 patient had an increased serum cobalt level. In the TMJ TJR group, 1 patient had an increased serum cobalt level and another patient had an increased serum chromium level. In the dental implant group, 1 patient had an increased serum titanium level and another had increased serum levels of titanium and chromium. CONCLUSIONS: This is the first study to report on the release of metal into the bloodstream in patients with different maxillofacial implanted metallic objects. The results raise questions regarding the types and magnitude of metal released from maxillofacial reconstruction devices and their potential long-term local and systemic effects. Future large-scale prospective studies involving serial measurements in homogeneous groups of patients could further elucidate the impact of these findings.


Asunto(s)
Artroplastia de Reemplazo/métodos , Cromo/sangre , Cobalto/sangre , Implantes Dentales , Cirugía Ortognática/métodos , Articulación Temporomandibular/cirugía , Titanio/sangre , Adulto , Anciano , Femenino , Humanos , Prótesis Articulares , Masculino , Persona de Mediana Edad , Proyectos Piloto
20.
Dent Mater ; 34(7): e182-e195, 2018 07.
Artículo en Inglés | MEDLINE | ID: mdl-29678329

RESUMEN

OBJECTIVE: Titanium dioxide (TiO2) incorporation in biomaterials is a promising technology due to its photocatalytic and antibacterial activities. However, the antibacterial potential of different TiO2 crystalline structures on a multispecies oral biofilm remains unknown. We hypothesized that the different crystalline TiO2 phases present different photocatalytic and antibacterial activities. METHODS: Three crystalline TiO2 films were deposited by magnetron sputtering on commercially pure titanium (cpTi), in order to obtain four groups: (1) machined cpTi (control); (2) A-TiO2 (anatase); (3) M-TiO2 (mixture of anatase and rutile); (4) R-TiO2 (rutile). The morphology, crystalline phase, chemical composition, hardness, elastic modulus and surface free energy of the surfaces were evaluated. The photocatalytic potential was assessed by methylene blue degradation assay. The antibacterial activity was evaluated on relevant oral bacteria, by using a multispecies biofilm (Streptococcus sanguinis, Actinomyces naeslundii and Fusobacterium nucleatum) formed on the treated titanium surfaces (16.5h) followed by UV-A light exposure (1h) to generate reactive oxygen species production. RESULTS: All TiO2 films presented around 300nm thickness and improved the hardness and elastic modulus of cpTi surfaces (p<0.05). A-TiO2 and M-TiO2 films presented superior photocatalytic activity than R-TiO2 (p<0.05). M-TiO2 revealed the greatest antibacterial activity followed by A-TiO2 (≈99.9% and 99% of bacterial reduction, respectively) (p<0.001 vs. control). R-TiO2 had no antibacterial activity (p>0.05 vs. control). SIGNIFICANCE: This study brings new insights on the development of extra oral protocols for the photocatalytic activity of TiO2 in oral biofilm-associated disease. Anatase and mixture-TiO2 showed antibacterial activity on this oral bacterial biofilm, being promising surface coatings for dental implant components.


Asunto(s)
Antibacterianos/farmacología , Biopelículas/efectos de los fármacos , Materiales Biocompatibles Revestidos/farmacología , Titanio/farmacología , Actinomyces , Antibacterianos/química , Materiales Biocompatibles Revestidos/química , Módulo de Elasticidad , Fusobacterium nucleatum , Dureza , Ensayo de Materiales , Microscopía de Fuerza Atómica , Microscopía Electrónica de Rastreo , Procesos Fotoquímicos , Espectrometría por Rayos X , Streptococcus sanguis , Propiedades de Superficie , Titanio/química , Difracción de Rayos X
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