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1.
Biology (Basel) ; 10(2)2021 Feb 10.
Artículo en Inglés | MEDLINE | ID: mdl-33578910

RESUMEN

Abiotic stresses will be one of the major challenges for worldwide food supply in the near future. Therefore, it is important to understand the physiological mechanisms that mediate plant responses to abiotic stresses. When subjected to UV, salinity or drought stress, plants accumulate specialized metabolites that are often correlated with their ability to cope with the stress. Among them, anthocyanins are the most studied intermediates of the phenylpropanoid pathway. However, their role in plant response to abiotic stresses is still under discussion. To better understand the effects of anthocyanins on plant physiology and morphogenesis, and their implications on drought stress tolerance, we used transgenic tobacco plants (AN1), which over-accumulated anthocyanins in all tissues. AN1 plants showed an altered phenotype in terms of leaf gas exchanges, leaf morphology, anatomy and metabolic profile, which conferred them with a higher drought tolerance compared to the wild-type plants. These results provide important insights for understanding the functional reason for anthocyanin accumulation in plants under stress.

3.
Magn Reson Imaging ; 76: 1-7, 2020 Nov 06.
Artículo en Inglés | MEDLINE | ID: mdl-33161101

RESUMEN

PURPOSE: The aim of this work is to test the use of aqueous solutions of Ficoll®**, a highly branched polymer displaying crowding properties, to build a phantom suitable for Diffusion Weighted Imaging (DWI) in Magnetic Resonance Imaging (MRI). METHODS: We developed a test object made of a cylindrical plastic container with a precise geometrical arrangement suitable for measuring several samples at the same time. The container was designed to host single vials with variable geometry and number, and to fit inside common commercial head coils for MRI scanners. In our experiments, vials were filled with 8 aqueous solutions of Ficoll 70 and Ficoll 400 spanning a range of polymer concentration from 5 to 30% by weight. Vials containing ultra-pure water were also used as reference. Experiments were performed on both 1.5 and 3 T clinical scanners (GE, Philips and Siemens), under the conditions of a standard clinical examination. RESULTS: The geometry of the phantom provided reduced imaging artifacts, especially image distortions at magnetic interfaces. We found that the Apparent Diffusion Coefficient (ADC) varied in the range of 0.00125-0.00223 mm2/s and decreased with Ficoll concentration. ADC vs Ficoll concentration exhibited a linear trend. Results were consistent over time and among different MRI clinical scanners, showing an average variability of 3% at 1.5 T and of 7.5% at 3 T. Moreover, no substantial difference was found between Ficoll 70 and 400. By varying Ficoll concentration, ADC can be modulated to approach tissue-mimicking values. Preliminary results for relaxation measurements proved that both T1 and T2 decreased with Ficoll concentration in the ranges 1.3-2.4 s and 150-800 ms respectively. CONCLUSIONS: In this work, we propose a 3D phantom design based on the widespread crowding agent Ficoll, which is suitable for DWI quality assurance purposes in MRI acquisitions. Aqueous Ficoll solutions provide good performance in terms of stability, ease of preparation, and safety.

4.
Arch Toxicol ; 2020 Oct 06.
Artículo en Inglés | MEDLINE | ID: mdl-33025067

RESUMEN

Health risk associated with the use of combustible cigarettes is well characterized and numerous epidemiological studies have been published for many years. Since more than a decade, innovative non-combusted tobacco products have emerged like heated tobacco products (HTP) or electronic cigarettes (EC). Long-term effects of these new products on health remain, however, unknown and there is a need to characterize associated potential health risks. The time dedicated to epidemiological data generation (at least 20 to 40 years for cancer endpoint), though, is not compatible with innovative development. Surrogates need, therefore, to be developed. In this work, non-cancer and cancer risks were estimated in a range of HTP and commercial combustible cigarettes based upon their harmful and potentially harmful constituent yields in aerosols and smoke, respectively. It appears that mean lifetime cancer risk values were decreased by more than one order of magnitude when comparing HTPs and commercial cigarettes, and significantly higher margin of exposure for non-cancer risk was observed for HTPs when compared to commercial cigarettes. The same approach was applied to two commercial ECs. Similar results were also found for this category of products. Despite uncertainties related to the factors used for the calculations and methodological limitations, this approach is valuable to estimate health risks associated to the use of innovative products. Moreover, it acts as predictive tool in absence of long-term epidemiological data. Furthermore, both cancer and non-cancer risks estimated for HTPs and ECs highlight the potential of reduced risk for non-combusted products when compared to cigarette smoking.

5.
Radiother Oncol ; 154: 14-20, 2020 Sep 12.
Artículo en Inglés | MEDLINE | ID: mdl-32926910

RESUMEN

PURPOSE: To analyze results from three years of in vivo transit EPID dosimetry of abdominal and pelvic stereotactic radiotherapy and to establish tolerance levels for routine clinical use. MATERIAL: 80 stereotactic VMAT treatments (152 fractions) targeting the abdomen or pelvis were analyzed. In vivo 3D doses were reconstructed with an EPID commercial algorithm. Gamma Agreement Index (GAI) and DVH differences in Planning Target Volume (PTV) and Clinical Target Volume (CTV) were evaluated. Initial tolerance level was set to GAI > 85% in PTV. Fractions Over Tolerance Level (OTL) were deemed to be due to set-up errors, incorrect use of immobilization devices, 4D errors, transit EPID algorithm errors and unknown/unidentified errors. Statistical Process Control (SPC) was applied to determine local tolerance levels. RESULTS: Average GAI were (82.7 ± 20.9) % in PTV and (72.9 ± 29.7) % in CTV. 37.8% of fractions resulted OTL and were classified as: set-up errors (3.3%), incorrect use of immobilization devices (2.1%), 4D errors (2.1%), EPID transit algorithm errors (17.1%). OTL causes for the remaining 13.2% of fractions were not identified. The differences between PTV and CTV measured in vivo and calculated mean dose (average difference ± standard deviation) were (-3.3% ± 3.2%) and (-2.3% ± 3.0%). When tolerance levels based on SPC to PTV mean dose differences were applied, the percentage of OTL decreased to 7% and no EPID algorithm error occurred. One error was not identified. CONCLUSIONS: The application of local tolerance levels to EPID in vivo dosimetry proved to be useful for detecting extra-lung SBRT treatment errors.

8.
ACS Appl Mater Interfaces ; 12(27): 30181-30188, 2020 Jul 08.
Artículo en Inglés | MEDLINE | ID: mdl-32551524

RESUMEN

In recent times, biomolecular sensing to recognize genetic fragments and proteins is spurring unprecedented interest as a diagnostic protocol for cancer and infectious diseases. Significant efforts have been made to design nanomaterials able to control the light-matter interaction at the single nanometer scale, where genes and proteins bind specifically to receptors. Here, we numerically show how the interface between a chiral metasurface and hyperbolic metamaterials can enable both high sensitivity and specificity for low-molecular-weight nucleic acids and proteins. As we have recently reported, hyperbolic dispersion metamaterials allow molecular biorecognition with extreme sensitivity because of coupled and highly confined plasmon polaritons. Specificity is almost exclusively achieved by receptor-ligand interaction at the in-plane sensing surface. Interestingly, an adapted out-of-plane chiral metasurface enables three key functionalities of the hyperbolic metamaterial sensor. Computational effort reveals that helicoidal metasurfaces can act as (i) efficient diffractive elements to excite surface and bulk plasmon polaritons; (ii) out-of-plane sensing branches to reduce the diffusion limit and increase the sensing surface; and (iii) biorecognition assay also via circular dichroism and chiral selectivity.

9.
Radiother Oncol ; 149: 158-167, 2020 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-32416282

RESUMEN

Stereotactic body radiation therapy (SBRT) has been recognized as a standard treatment option for many anatomical sites. Sophisticated radiation therapy techniques have been developed for carrying out these treatments and new quality assurance (QA) programs are therefore required to guarantee high geometrical and dosimetric accuracy. This paper focuses on recent advances on in-vivo measurements methods (IVM) for SBRT treatment. More specifically, all of the online QA methods for estimating the effective dose delivered to patients were compared. Determining the optimal IVM for performing SBRT treatments would reduce the risk of errors that could jeopardize treatment outcome. A total of 89 papers were included. The papers were subdivided into the following topics: point dosimeters (PD), transmission detectors (TD), log file analysis (LFA), electronic portal imaging device dosimetry (EPID), dose accumulation methods (DAM). The detectability capability of the main IVM detectors/devices were evaluated. All of the systems have some limitations: PD has no spatial data, EPID has limited sensitivity towards set-up errors and intra-fraction motion in some anatomical sites, TD is insensitive towards patient related errors, LFA is not an independent measure, DAMs are not always based on measures. In order to minimize errors in SBRT dose delivery, we recommend using synergic combinations of two or more of the systems described in our review: on-line tumor position and patient information should be combined with MLC position and linac output detection accuracy. In this way the effects of SBRT dose delivery errors will be reduced.

10.
Vet Res ; 51(1): 2, 2020 Jan 10.
Artículo en Inglés | MEDLINE | ID: mdl-31924278

RESUMEN

The avian respiratory tract is a common entry route for many pathogens and an important delivery route for vaccination in the poultry industry. Immune responses in the avian lung have mostly been studied in vivo due to the lack of robust, relevant in vitro and ex vivo models mimicking the microenvironment. Precision-cut lung slices (PCLS) have the major advantages of maintaining the 3-dimensional architecture of the lung and includes heterogeneous cell populations. PCLS have been obtained from a number of mammalian species and from chicken embryos. However, as the embryonic lung is physiologically undifferentiated and immunologically immature, it is less suitable to examine complex host-pathogen interactions including antimicrobial responses. Here we prepared PCLS from immunologically mature chicken lungs, tested different culture conditions, and found that serum supplementation has a detrimental effect on the quality of PCLS. Viable cells in PCLS remained present for ≥ 40 days, as determined by viability assays and sustained motility of fluorescent mononuclear phagocytic cells. The PCLS were responsive to lipopolysaccharide stimulation, which induced the release of nitric oxide, IL-1ß, type I interferons and IL-10. Mononuclear phagocytes within the tissue maintained phagocytic activity, with live cell imaging capturing interactions with latex beads and an avian pathogenic Escherichia coli strain. Finally, the PCLS were also shown to be permissive to infection with low pathogenic avian influenza viruses. Taken together, immunologically mature chicken PCLS provide a suitable model to simulate live organ responsiveness and cell dynamics, which can be readily exploited to examine host-pathogen interactions and inflammatory responses.


Asunto(s)
Pollos , Interacciones Huésped-Patógeno/inmunología , Pulmón/inmunología , Enfermedades de las Aves de Corral/inmunología , Medicina Veterinaria/métodos , Animales , Pollos/inmunología , Lipopolisacáridos/metabolismo , Pulmón/microbiología , Pulmón/parasitología , Enfermedades de las Aves de Corral/microbiología , Enfermedades de las Aves de Corral/parasitología
11.
Chem Res Toxicol ; 33(2): 657-668, 2020 02 17.
Artículo en Inglés | MEDLINE | ID: mdl-31859484

RESUMEN

A broad range of commercially available electronic cigarette (e-cigarette) systems were tested for levels of emissions of harmful and potentially harmful constituents (HPHC), with a particular focus on the carbonyls: acetaldehyde, acrolein, and formaldehyde. The tobacco-specific nitrosamines N'-nitrosonornicotine and 4-(methylnitrosamino)-1-(3-bipyridyl)-1-butanone; the elements arsenic, cadmium, chromium, lead, and nickel; benzene; 1,3-butadiene; and benzo(a)pyrene were also quantified. The results show that except for the levels of carbonyls, all types of e-cigarettes performed in a similar manner, and emission levels for HPHCs were generally not quantifiable. However, levels of carbonyls, especially formaldehyde, were highly variable. Overall, the lowest levels of formaldehyde were observed in cartridge systems, which generally achieved substantial reductions in yields in comparison with cigarette smoke. Formaldehyde levels in open tank systems were variable; however, the median formaldehyde levels across different brands were substantially lower than the formaldehyde levels in cigarette smoke. The results for variable-power devices operated at the highest voltage confirmed existing literature data regardless of orientation and differences in puffing regimes. Furthermore, our results show that many products deliver consistent HPHC yields over a broad range of testing conditions (with minimal variability from one device to another, under a range of puffing conditions). However, some products exhibit high variability in emissions of HPHCs. The use of air blanks is further highlighted to assess nonproduct-related contributions to HPHC levels to avoid misrepresentation of the data. Overall, our results highlight that some but not all electronic cigarettes deliver low levels of carbonyls consistently across the full e-liquid depletion cycle under different test conditions. The need for further research and standardization work on assessment of variable-voltage electronic cigarettes is emphasized.

12.
Int J Radiat Oncol Biol Phys ; 106(2): 403-412, 2020 02 01.
Artículo en Inglés | MEDLINE | ID: mdl-31707124

RESUMEN

In this review a summary of the published literature pertaining to the stereotactic body radiation therapy multiplanning comparison, data sharing strategies, and implementation of benchmark planning cases to improve the skills and knowledge of the participating centers was investigated. A total of 30 full-text articles were included. The studies were subdivided in 3 categories: multiplanning studies on dosimetric variability, planning harmonization before clinical trials, and technical and methodologic studies. The methodology used in the studies were critically analyzed to find common and original elements with the pros and cons. Multicenter planning studies have played a key role in improving treatment plan harmonization, treatment plan compliance, and even clinical practices. This review has highlighted that some fundamental steps should be taken to transform a simple treatment planning comparison study into a potential credentialing method for stereotactic body radiation therapy accreditation. In particular, prescription and general requirements should always be well defined; data analysis should be performed with independent dose volume histogram or dose calculations; quality score indices should be constructed; feedback and correction strategies should be provided; and a simple web-based collaboration platform should be used. The results reported clearly showed that a crowd-based replanning approach is a viable method for achieving harmonization and standardization of treatment planning among centers using different technologies.


Asunto(s)
Benchmarking , Estudios Multicéntricos como Asunto , Radiocirugia/métodos , Dosificación Radioterapéutica , Acreditación , Ensayos Clínicos como Asunto , Habilitación Profesional , Humanos , Órganos en Riesgo/efectos de la radiación
13.
Cochrane Database Syst Rev ; 10: CD003815, 2019 Oct 10.
Artículo en Inglés | MEDLINE | ID: mdl-31600407

RESUMEN

BACKGROUND: Dental implants are available in different materials, shapes and with different surface characteristics. In particular, numerous implant designs and surface modifications have been developed for improving clinical outcome. This is an update of a Cochrane review first published in 2002, and previously updated in 2003, 2005 and 2007. OBJECTIVES: Primary: to compare the clinical effects of different root-formed osseointegrated dental implant types for replacing missing teeth for the following specific comparisons: implants with different surface preparations, but having similar shape and material; implants with different shapes, but having similar surface preparation and material; implants made of different materials, but having similar surface preparation and shape; different implant types differing in surface preparation, shape, material or a combination of these.Secondary: to compare turned and roughened dental implants for occurrence of early implant failure (before prosthetic loading) and occurrence of peri-implantitis. SEARCH METHODS: We searched the following electronic databases: the Cochrane Oral Health Group's Trials Register (to 17 January 2014), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2013, Issue 12), MEDLINE via OVID (1946 to 17 January 2014) and EMBASE via OVID (1980 to 17 January 2014). We placed no restrictions on the language or date of publication when searching the electronic databases. SELECTION CRITERIA: We included any randomised controlled trial (RCT) comparing osseointegrated dental implants of different materials, shapes and surface properties having a follow-up in function of at least one year. Outcome measures were success of the implants, radiographic peri-implant marginal bone levels changes and incidence of peri-implantitis. DATA COLLECTION AND ANALYSIS: At least two review authors independently conducted screening, risk of bias assessment and data extraction of eligible trials in duplicate. We expressed results using fixed-effect models (if up to three studies were present in a meta-analysis) or random-effects models (when there were more than three studies) using mean differences (MD) for continuous outcomes and risk ratios (RR) for dichotomous outcomes with 95% confidence intervals (CI). We reported the following endpoints: one, three, five and 10 years after functional loading. MAIN RESULTS: We identified 81 different RCTs. We included 27 of these RCTs, reporting results from 1512 participants and 3230 implants in the review. We compared 38 different implant types with a follow-up ranging from one to 10 years. All implants were made of commercially pure titanium or its alloys, and had different shapes and surface preparations. We judged two trials to be at low risk of bias, 10 to be at unclear risk of bias and 15 to be at high risk of bias. On a 'per participant' rather than 'per implant' basis, we found no significant differences between various implant types for implant failures. The only observed statistically significant difference for the primary objective regarded more peri-implant bone loss at Nobel Speedy Groovy implants when compared with NobelActive implants (MD -0.59 mm; 95% CI -0.74 to -0.44, different implant shapes). The only observed statistically significant difference for the secondary objective was that implants with turned (smoother) surfaces had a 20% reduction in risk to be affected by peri-implantitis than implants with rough surfaces three years after loading (RR 0.80; 95% CI 0.67 to 0.96). There was a tendency for implants with turned surfaces to fail early more often than implants with roughened surfaces. AUTHORS' CONCLUSIONS: Based on the results of the included RCTs, we found no evidence showing that any particular type of dental implant had superior long-term success. There was limited evidence showing that implants with relatively smooth (turned) surfaces were less prone to lose bone due to chronic infection (peri-implantitis) than implants with much rougher surfaces (titanium-plasma-sprayed). These findings were based on several RCTs, often at high risk of bias, with few participants and relatively short follow-up periods.

14.
Int J Oral Implantol (Berl) ; 12(3): 267-280, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31535097

RESUMEN

PURPOSE: To compare the clinical outcome of fixed prostheses supported by 4- to 8-mm-long implants with prostheses supported by longer implants placed in vertically augmented atrophic mandibles after a follow-up of 5 years in function. MATERIALS AND METHODS: The Cochrane Central Register of Controlled Trials (CENTRAL) and MEDLINE were searched up to 1st September 2018 for randomised controlled trials (RCTs) with a follow-up of at least 5 years in function comparing fixed prostheses supported by 4- to 8-mm-long implants with prostheses supported by longer implants placed in vertically augmented atrophic mandibles. Outcome measures were prosthesis failure, implant failures, augmentation procedure failures, complications, and peri-implant marginal bone level changes. Screening of eligible studies, assessment of the risk of bias and data extraction were conducted in duplicate and independently by two review authors. The statistical unit of the analysis was the prosthesis. Results were expressed as random-effects models using mean differences for continuous outcomes and risk ratios (RR) for dichotomous outcomes with 95% confidence intervals (CIs). RESULTS: Four eligible RCTs that included originally 135 patients were included. Two RCTs had a parallel-group design and two a split-mouth design. Short implants were 5.0 to 6.6 mm long and were compared with longer implants placed in posterior mandibles augmented with interpositional blocks of bone substitutes. All trials were judged at unclear risk of bias. Twelve (14%) bone augmentation procedures failed to achieve the planned bone height to allow placement of implants with the planned length. Five years after loading, 28 patients (21%) had dropped out from the four RCTs. There were no differences for patients having prosthesis (RR = 1.46; 95% CI: 0.52 to 4.09; P = 0.47; I2 = 0%) or implant (RR = 1.00; 95% CI: 0.31 to 3.21; P = 1.00; I2 = 0%) failures between the two interventions, but there were more patients experiencing complications (RR = 4.72; 95% CI: 2.43 to 9.17; P < 0.00001; I2 = 0%) and peri-implant marginal bone loss (mean difference = 0.60 mm; 95% CI: 0.36 to 0.83; P < 0.00001; I2 = 45%) at longer implants in augmented bone. CONCLUSIONS: Five years after loading, prosthetic and implant failures were similar between the two interventions, but complications and peri-implant marginal bone loss were higher and more severe at longer implants placed in vertically augmented mandibles. Larger trials and longer follow-ups up to 10 years after loading are needed to confirm or reject the present preliminary findings. However in the meantime short implants could be the preferable option.


Asunto(s)
Aumento de la Cresta Alveolar , Implantes Dentales , Implantación Dental Endoósea , Diseño de Prótesis Dental , Prótesis Dental de Soporte Implantado , Fracaso de la Restauración Dental , Estudios de Seguimiento , Humanos , Mandíbula , Ensayos Clínicos Controlados Aleatorios como Asunto , Resultado del Tratamiento
15.
Phys Med ; 62: 73-82, 2019 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-31153401

RESUMEN

PURPOSE: To evaluate, in a multi-institutional context, the role of Dose Volume Histogram (DVH) sharing in order to achieve higher plan quality, to harmonize prostate Stereotactic Body Radiation Therapy (SBRT) plans and to assess if the planner's experience in SBRT could lead to lower dose at organs at risk (OARs). METHODS: During the first phase five patients enrolled for prostate SBRT were planned by multiple physicists according to common protocol. The prescription dose was 35 Gy in 5 fractions. Dosimetric parameters, modulation index (MIt), plan parameters, and planner experience level (EL) were statistically analyzed. During the second phase median DVHs from all centers were shared and physicists replanned one patient of the five, aiming at inter-planner harmonization and further OARs sparing. Data were summarized by Spearman-correlogram (p < 0.05) and boxplots. The Kruskal-Wallis test was used to compare the re-plans to the original plans. RESULTS: Seventy-eight SBRT plans from 13 centers were evaluated. EL correlated with modulation of plan parameters and reduction of OARs doses, such as volume receiving 28 Gy of rectum (rectum-V28Gy), rectum-V32Gy, and bladder-V30Gy. The re-plans showed significant reduced variability in rectum-V28Gy and increased PTV dose homogeneity. No significant difference in plan complexity metrics and plan parameters between plans and re-plans were obtained. CONCLUSIONS: Planner's experience in prostate SBRT was correlated with dosimetric parameters. Sharing median DVHs reduced variability among centers whilst keeping the same level of plan complexity. SBRT planning skills can benefit from a replanning phase after sharing DVHs from multiple centers, improving plan quality and concordance among centers.


Asunto(s)
Neoplasias de la Próstata/radioterapia , Radiocirugia , Planificación de la Radioterapia Asistida por Computador/métodos , Humanos , Masculino , Órganos en Riesgo/efectos de la radiación , Control de Calidad , Radiocirugia/efectos adversos , Dosificación Radioterapéutica
17.
Int J Oral Implantol (Berl) ; 12(1): 13-22, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31116185

RESUMEN

PURPOSE: The purpose of this study was to evaluate the role of keratinised mucosa on the long-term success of dental implants. MATERIALS AND METHODS: Thirty-two edentulous patients had one of their dental arches rehabilitated with a provisional screw-retained resin reinforced cross-arch fixed prosthesis supported by four immediately loaded implants. The two central straight implants were randomly allocated in two equal groups, according to a parallel-group design, to receive or not intermediate abutments (Multi-Unit Abutment, MUA). However, for the purpose of the present publication, the study was considered as a prospective single cohort study. To be immediately loaded, implants had to be inserted with a minimum torque of 30 Ncm, which was achieved by all implants. Provisional prostheses were delivered within 24 hours and were replaced, after 4 months, by definitive screw-retained metal-ceramic prostheses. Patients were followed up to 5 years after loading. Prostheses were removed every 8 months to facilitate professionally delivered maintenance. Outcome measures were prosthesis and implant failures, complications, peri-implant marginal bone level (MBL) changes, bleeding on probing (BoP) and keratinised mucosa height (KMH). The absence of vestibular or lingual keratinised mucosa was put in relation with peri-implant bone loss and BoP. RESULTS: Five-years after loading two patients dropped out and no implant or prosthetic failure occurred. Four patients were affected by prosthetic complications. At delivery of definitive prostheses, 32 (25%) implants had at least one vestibular or lingual site with no KMH and 96 (75%) implants had both sites with some KMH. Multi-level models did not show any statistically significant association between KMH at the time of delivery of the definitive prosthesis and changes in MBL and BoP at 5 years (estimate = 0.02; 95% CI: -0.02 to 0.05; P = 0.3393; and 1.02; 95% CI: 0.79 to 1.33; P = 0.8695, respectively). When KMH was analysed as dichotomous variable, implants with presence of KMH at delivery of definitive prosthesis at both vestibular and lingual aspects showed a trend of less BoP (estimate = -0.8; 95% CI: -1.69 to 0.08; P = 0.0741) but a statistically significant greater MBL loss compared to implants where KMH was only present at one site (estimate = 0.18; 95% CI: -0.1 to 0.3; P = 0.0041). CONCLUSIONS: The 5-year after loading outcome of immediately loaded screw-retained cross-arch prostheses supported by four implants is excellent in both the maxilla and mandible. Although the height of the keratinised mucosa did not seem to alter the clinical outcomes, its presence both at vestibular and lingual sites was associated with an increased marginal bone loss when compared to implants having at least one side without keratinised mucosa.


Asunto(s)
Implantes Dentales , Carga Inmediata del Implante Dental , Estudios de Cohortes , Prótesis Dental de Soporte Implantado , Humanos , Membrana Mucosa , Estudios Prospectivos
18.
Int J Oral Implantol (Berl) ; 12(1): 25-37, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31116186

RESUMEN

PURPOSE: To evaluate whether 5-mm short dental implants could be an alternative to augmentation with anorganic bovine bone and placement of at least 10-mm long implants in posterior atrophic jaws. MATERIALS AND METHODS: Fifteen patients with bilateral atrophic mandibles (5 to 7 mm bone height above the mandibular canal) and 15 patients with bilateral atrophic maxillae (4 to 6 mm bone height below the maxillary sinus), and bone thickness of at least 8 mm, were randomised according to a split-mouth design to receive one to three 5-mm short implants or at least 10-mm long implants in augmented bone. Mandibles were vertically augmented with interpositional bone blocks and maxillary sinuses with particulated bone via a lateral window. Implants were placed after 4 months, submerged and loaded, after another 4 months, with provisional prostheses. Four months later, definitive provisionally cemented prostheses were delivered. Outcome measures were: prosthesis and implant failures, any complication and peri-implant marginal bone level changes. RESULTS: In five augmented mandibles the planned 10-mm long implants could not be placed and shorter implants (7.0 and 8.5 mm) had to be used instead. Five years after loading, six patients, five treated in the mandible and one in the maxilla, dropped out. Three prostheses (one mandibular and two maxillary) failed in the short-implant group versus none in the long-implant group. In mandibles one long implant failed versus two short implants in one patient. In maxillae one long implant failed versus three short implants in two patients. There were no statistically significant differences in implant (n = 26; P = 1.00, difference = 3.85%, 95% CI: -12.95% to 20.64%) and prosthetic (n = 26; P = 0.250, difference = 11.54%, 95% CI: -0.74% to 23.82%) failures. Eleven patients had 16 complications at short implants (one patient accounted for six complications) and 12 patients had 14 complications at long implants. There were no statistically significant differences in complications (n = 28; P = 1.00, difference = -3.57%, 95% CI: -30.65% to 23.51%). Five years after loading, patients with mandibular implants lost on average 1.72 mm at short implants and 2.10 mm at long implants of peri-implant marginal bone. This difference was statistically significant (difference = 0.37 ± 0.43 mm; 95% CI: 0.07 to 0.68 mm; P = 0.022). In maxillae, patients lost on average 1.31 mm at short implants and 1.79 mm at long implants. This difference was statistically significant (difference = 0.48 ± 0.43 mm; 95% CI: 0.22 to 0.74 mm; P = 0.002). CONCLUSIONS: Five years after loading, 5-mm short implants achieved similar results to longer implants in augmented bone. The choice of short implants might be preferable to vertical bone augmentation, especially in mandibles, since the treatment is faster and cheaper.


Asunto(s)
Aumento de la Cresta Alveolar , Arcada Edéntula , Animales , Bovinos , Implantación Dental Endoósea , Diseño de Prótesis Dental , Prótesis Dental de Soporte Implantado , Fracaso de la Restauración Dental , Humanos
19.
Int J Oral Implantol (Berl) ; 12(1): 39-54, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31116187

RESUMEN

PURPOSE: To evaluate whether 5 × 5 mm dental implants with a novel nanostructured calcium-incorporated titanium surface could be an alternative to implants at least 10-mm long placed in bone augmented with bone substitutes in posterior atrophic jaws. MATERIALS AND METHODS: Forty patients with atrophic posterior (premolar and molar areas) mandibles having 5- to 7-mm bone height above the mandibular canal, and 40 patients with atrophic maxillae having 4- to 6-mm bone height below the maxillary sinus, were randomised according to a parallel-group design to receive one to three 5-mm implants or one to three at least 10-mm long implants in augmented bone at two centres. All implants had a diameter of 5 mm. Mandibles were vertically augmented with interpositional bovine bone blocks covered with resorbable barriers. Implants were placed after 4 months. Maxillary sinuses were augmented with particulated porcine bone via a lateral window covered with resorbable barriers and implants were placed simultaneously. All implants were submerged and loaded after 4 months with provisional prostheses. Four months later, definitive screw-retained or provisionally cemented metal-ceramic or zirconia prostheses were delivered. Patients were followed to 5 years post-loading and the outcome measures were: prosthesis and implant failures, any complication and peri-implant marginal bone level changes. RESULTS: Sixteen patients dropped out before the 5-year evaluation (four short mandibles, three short maxillae, six augmented mandibles and three augmented maxillae). In mandibles, two grafted patients were not prosthetically rehabilitated because of multiple complications, and three implants failed in the same patient (one was a replacement implant) versus one patient who lost his short implant and crown 2 years after loading. In maxillae one short implant failed with its provisional crown 3 months post-loading. There were no statistically significant differences in prostheses (difference in proportion = -0.003; 95% CI: -0.14 to 0.13; P = 1.000) and implant failures (difference in proportion = -0.03; 95% CI: -0.17 to 0.09; P = 0.609) up to 5 years after loading. Significantly more complications occurred at mandibular grafted sites: 17 augmented patients were affected by complications versus nine patients treated with short implants in mandibles (difference in proportion = 0.39; 95% CI: 0.10 to 0.62; P = 0.013). In the maxilla seven sinus-elevated patients versus two patients treated with short implants were affected by complications, the difference not being statistically significant (difference in proportion = 0.25; 95% CI: -0.04 to 0.49; P = 0.128). Patients with mandibular short implants lost on average 1.22 mm of peri-implant bone at 5 years and patients with 10-mm or longer mandibular implants lost 1.70 mm. Patients with maxillary short implants lost on average 1.25 mm of peri-implant bone at 5 years and patients with 10-mm or longer maxillary implants lost 1.73 mm. Longer implants showed a greater bone loss up to 5 years after loading than short implants both in maxillae (mean difference: -0.48 mm; 95% CI: -0.89 to -0.07 mm; P = 0.024) and in mandibles (mean difference: -0.48 mm; 95% CI: -0.79 to -0.18 mm; P = 0.004). CONCLUSIONS: Five years after loading, 5 × 5 mm implants achieved similar results to longer implants placed in augmented bone. Short implants might be a preferable choice to bone augmentation especially in posterior mandibles since the treatment is faster, cheaper and associated with less morbidity; however, 10-year post-loading data are necessary before making reliable recommendations.


Asunto(s)
Aumento de la Cresta Alveolar , Titanio , Animales , Bovinos , Implantación Dental Endoósea , Diseño de Prótesis Dental , Prótesis Dental de Soporte Implantado , Fracaso de la Restauración Dental , Humanos
20.
Int J Oral Implantol (Berl) ; 12(1): 57-72, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31116188

RESUMEN

PURPOSE: To evaluate whether 6-mm-long by 4-mm-wide dental implants could be an alternative to implants at least 10-mm long placed in bone augmented with bone substitutes in posterior atrophic jaws. MATERIALS AND METHODS: A total of 20 patients with bilateral atrophic mandibles and 20 patients with bilateral atrophic maxillae, having 5 to 7 mm of bone height below the maxillary sinus or 6 to 8 mm above the mandibular canal, had their sides of the jaws randomly allocated according to a split-mouth design. They were allocated to receive one to three 6-mm-long and 4-mm-wide implants, or implants at least 10-mm long in augmented bone by two different surgeons in different centres. Mandibles were vertically augmented with interpositional equine bone blocks and resorbable barriers, and implants were placed 3 months later. Maxillary sinuses were augmented with particulated porcine bone via a lateral window and implants were placed simultaneously. All implants were submerged and loaded, after 4 months, with provisional prostheses. Four months later, definitive prostheses were delivered. Outcome measures were prosthesis and implant failures, any complication and radiographic peri-implant marginal bone level changes. The follow-up was 5 years after loading for all patients. RESULTS: Eight patients (five treated in mandibles and three in maxillae) dropped out before the 5-year post-loading follow-up. Four short implants (two maxillary and two mandibular) affected by peri-implantitis failed together with their prostheses versus three mandibular prostheses which could not be placed on implants at least 10-mm long due to graft failures; one was associated with the loss of three implants because of infection. There were no statistically significant differences in implant (P = 1.0) and prosthesis failures (P = 1.0). In total, 19 complications occurred in 14 patients at augmented sites versus five complications in four patients with 6-mm-long implants (P = 0.118). More complications occurred at grafted sites both in mandibles (P = 0.727), and maxillae (P = 0.063), although the differences were not statistically significant. In mandibles, patients with 6-mm-long implants lost an average of 1.34 ± 0.35 mm of peri-implant bone at 5 years versus 2.11 ± 0.59 mm in patients with implants at least 10-mm long. The difference was statistically significant (mean difference = 0.77 ± 0.70 mm; 95% CI: 0.32 to 1.21 mm; P = 0.003). In maxillae, patients with 6-mm-long implants lost an average of 1.52 ± 0.47 mm of peri-implant bone at 5 years versus 1.85 ± 0.51 mm in patients with implants at least 10-mm long. The difference was statistically significant (mean difference = 0.33 ± 0.36 mm; 95% CI: 0.14 to 0.53 mm; P = 0.002). CONCLUSIONS: Results at 5 years after loading indicate that 6-mm-long implants with a conventional diameter of 4 mm achieved similar results to longer implants placed in augmented bone. Short implants might be a preferable choice to bone augmentation, especially in posterior mandibles since the treatment was faster, cheaper and associated with less morbidity. However, 10-year post-loading data are necessary before making reliable recommendations.


Asunto(s)
Aumento de la Cresta Alveolar , Implantación Dental Endoósea , Animales , Diseño de Prótesis Dental , Prótesis Dental de Soporte Implantado , Fracaso de la Restauración Dental , Caballos , Humanos
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