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1.
Int J Prosthodont ; 2021 Feb 12.
Artículo en Inglés | MEDLINE | ID: mdl-33616558

RESUMEN

PURPOSE: To investigate and compare the production tolerances of six different commercially available implant scan bodies (SBs), with the null hypothesis that there would be no tolerances in the production or significant differences between the different SBs. MATERIALS AND METHODS: Six different implant SBs (IO 6A-B and IO 2B-B, Nobel Biocare; RC 4.1 mm 025.4915 and RN 4.8 mm 048.168, Straumann; KR 352KR1A0, BTK BIOTEC; and AANISR4013T, MegaGen) were evaluated. Five specimens of each SB type (a total of 30 samples) were screwed onto the corresponding implant analogs and underwent dimensional analysis with optical microscopy (QVI Smartscope Flash 200, Optical Gaging Products) and precision probing (R 0.25, Renishaw). The outcome variables were SB height, diameter, and angle of the flat face on the top (plane). All measurements were compared with the corresponding computer-assisted design library measurements used as a reference to assess the manufacturing tolerances. Statistical analyses were performed to compare the results obtained with the different SBs. RESULTS: Tolerances in the manufacture of the SBs were reported in height, diameter, and plane measurements, and statistically significant differences between the different types of SBs were found. Therefore, the null hypothesis was rejected. Most of the deviations and tolerances were reported in height measurements with conical connection implants. CONCLUSIONS: Tolerances in the production and statistically significant differences were found among the six commercially available SBs evaluated in this study. Additional studies with larger sample sizes and other types of SBs are needed.

2.
Artículo en Inglés | MEDLINE | ID: mdl-33528449

RESUMEN

This prospective longitudinal clinical trial aimed to evaluate the success of a bone-level implant with an integrated platform-switched connection by assessing peri-implant soft tissue and marginal bone level. Twenty-six patients were treated in two different centers with implants placed in healed partially edentulous ridges. Implant success rate and marginal bone level were evaluated with photographs, radiographs, and clinical measurements, with a 6-month postloading follow-up. The esthetic appearance of the photographed peri-implant soft tissue was evaluated at 6 months via the Pink Esthetic Score applied by two calibrated operators. All of the implants except for one placed in the mandible demonstrated successful osseointegration, resulting in a success rate of 97.8% at the 6-month follow-up. Compared to historical controls, no detectable differences in peri-implant marginal bone loss or esthetic outcome were seen.


Asunto(s)
Pérdida de Hueso Alveolar , Implantes Dentales , Pérdida de Hueso Alveolar/diagnóstico por imagen , Implantación Dental Endoósea , Estudios de Seguimiento , Humanos , Mandíbula/cirugía , Oseointegración , Estudios Prospectivos
3.
Artículo en Inglés | MEDLINE | ID: mdl-32231082

RESUMEN

Peri-implant soft tissues play a role of paramount importance, not only on the esthetic appearance, but also on the maintenance and long-term stability of implants. The present report presents the conclusions from the Consensus Conference of the South European North African Middle Eastern Implantology & Modern Dentistry Association (SENAME) (4-6 November 2016, Cairo, Egypt). The conference focused on the topic of the soft tissue around dental implants, and in particular, on the influence of implant configurations on the marginal soft tissues, soft tissue alterations after immediate, early or delayed implant placement and immediate loading, the long-term outcomes of soft tissue stability around dental implants, and soft tissue augmentation around dental implants. Thirty world experts in this field were invited to take part in this two-day event; however, only 29 experts were in the final consensus voting process.


Asunto(s)
Implantes Dentales , Mucosa Bucal , Consenso , Egipto , Humanos
4.
Nanomaterials (Basel) ; 9(11)2019 Nov 11.
Artículo en Inglés | MEDLINE | ID: mdl-31717979

RESUMEN

Metal-insulator-semiconductor-insulator-metal (MISIM) heterostructures, with rectifying current-voltage characteristics and photosensitivity in the visible and near-infrared spectra, are fabricated and studied. It is shown that the photocurrent can be enhanced by adding a multi-walled carbon nanotube film in the contact region to achieve a responsivity higher than 100   mA   W - 1 under incandescent light of 0.1   mW   cm - 2 . The optoelectrical characteristics of the MISIM heterostructures are investigated at lower and higher biases and are explained by a band model based on two asymmetric back-to-back Schottky barriers. The forward current of the heterojunctions is due to majority-carrier injection over the lower barrier, while the reverse current exhibits two different conduction regimes corresponding to the diffusion of thermal/photo generated carriers and majority-carrier tunneling through the higher Schottky barrier. The two conduction regimes in reverse bias generate two plateaus, over which the photocurrent increases linearly with the light intensity that endows the detector with bias-controlled photocurrent.

5.
Nanomaterials (Basel) ; 9(5)2019 May 09.
Artículo en Inglés | MEDLINE | ID: mdl-31075873

RESUMEN

Nanostructured materials have wide potential applicability as field emitters due to their high aspect ratio. We hydrothermally synthesized MoS2 nanoflowers on copper foil and characterized their field emission properties, by applying a tip-anode configuration in which a tungsten tip with curvature radius down to 30-100 nm has been used as the anode to measure local properties from small areas down to 1-100 µm2. We demonstrate that MoS2 nanoflowers can be competitive with other well-established field emitters. Indeed, we show that a stable field emission current can be measured with a turn-on field as low as 12 V/µm and a field enhancement factor up to 880 at 0.6 µm cathode-anode separation distance.

6.
Nanomaterials (Basel) ; 9(5)2019 Apr 26.
Artículo en Inglés | MEDLINE | ID: mdl-31027368

RESUMEN

A graphene/silicon junction with rectifying behaviour and remarkable photo-response was fabricated by transferring a graphene monolayer on a pillar-patterned Si substrate. The device forms a 0.11 eV Schottky barrier with 2.6 ideality factor at room temperature and exhibits strongly bias- and temperature-dependent reverse current. Below room temperature, the reverse current grows exponentially with the applied voltage because the pillar-enhanced electric field lowers the Schottky barrier. Conversely, at higher temperatures, the charge carrier thermal generation is dominant and the reverse current becomes weakly bias-dependent. A quasi-saturated reverse current is similarly observed at room temperature when the charge carriers are photogenerated under light exposure. The device shows photovoltaic effect with 0.7% power conversion efficiency and achieves 88 A/W photoresponsivity when used as photodetector.

7.
Nanoscale ; 11(4): 1538-1548, 2019 Jan 23.
Artículo en Inglés | MEDLINE | ID: mdl-30629066

RESUMEN

We report the first observation of a gate-controlled field emission current from a tungsten diselenide (WSe2) monolayer, synthesized by chemical-vapour deposition on a SiO2/Si substrate. Ni contacted WSe2 monolayer back-gated transistors, under high vacuum, exhibit n-type conduction and drain-bias dependent transfer characteristics, which are attributed to oxygen/water desorption and drain induced Schottky barrier lowering, respectively. The gate-tuned n-type conduction enables field emission, i.e. the extraction of electrons by quantum tunnelling, even from the flat part of the WSe2 monolayers. Electron emission occurs under an electric field ∼100 V µm-1 and exhibits good time stability. Remarkably, the field emission current can be modulated by the back-gate voltage. The first field-emission vertical transistor based on the WSe2 monolayer is thus demonstrated and can pave the way to further optimize new WSe2 based devices for use in vacuum electronics.

8.
Artículo en Inglés | MEDLINE | ID: mdl-29889918

RESUMEN

To accurately assess the long-term performance of anodized-surface implants, more data monitoring is needed outside of clinical evaluations. This retrospective study evaluated long-term implant survival and bone remodeling after up to 12 years of function. Data from 195 implants placed in 60 patients over a follow-up period ranging from 0.6 to 12.1 years were included. The implant-level survival rate was 99.0%. Marginal bone loss remained low across all follow-up cohorts. The data show that anodized-surface implants are a safe, reliable option with high implant survival rates and low levels of bone loss.


Asunto(s)
Implantación Dental Endoósea/estadística & datos numéricos , Implantes Dentales/estadística & datos numéricos , Fracaso de la Restauración Dental/estadística & datos numéricos , Pérdida de Hueso Alveolar/diagnóstico por imagen , Remodelación Ósea , Arco Dental/diagnóstico por imagen , Arco Dental/cirugía , Diseño de Prótesis Dental , Prótesis Dental de Soporte Implantado , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Propiedades de Superficie , Titanio , Resultado del Tratamiento
9.
Artículo en Inglés | MEDLINE | ID: mdl-29732018

RESUMEN

Background. In the current scientific literature there are only few studies on the immediate functional loading of single implants. The aim of the present present study was to evaluate the 4-year survival rate, complication rate and peri-implant marginal bone loss (PIMBL) of immediately loaded single implants inserted in healed ridges and fresh post-extraction sites. Methods. Six centers were involved in this prospective study. The surgical and prosthetic protocol was defined in detail, before the start of recruiting patients. Recruitment of patients and performance of surgeries took place between February 2012 and February 2013. Criteria for inclusion were single-tooth gaps in healed ridges and fresh post-extraction sockets. All the fixtures (Anyridge®, Megagen Corporation, Gyeongbuk, South Korea) were functionally loaded immediately after insertion and followed for a period of 4 years. Outcome measures were implant survival, complications and PIMBL. Results. Forty-six patients (18‒73 years of age) were selected. In total, 57 fixtures were placed (10 in fresh post-extraction sockets). After 4 years of functional loading, only one fixture was lost; therefore, high survival rates (97.6% patient-based; 98.1% implant-based) were reported. In addition, a limited incidence of biologic (4.8% patient-based; 3.8% implant-based) and prosthetic (9.7% patient-based; 7.6% implant-based) complications was reported. The overall 4-year PIMBL amounted to 0.38±0.21 mm (healed ridges: 0.4±0.21 mm; fresh post-extraction sockets: 0.33±0.20 mm). Conclusion. Loading single implants immediately seems to be a highly successful treatment modality. However, long-term data are needed to confirm these positive outcomes.

10.
Open Dent J ; 12: 118-124, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29492177

RESUMEN

Objective: The objective of the present study was to compare patients' acceptability, comfort and stress with conventional and digital impressions. Materials and Methods: Thirty young orthodontic patients (15 males and 15 females) who had no previous experience of impressions were enrolled in this study. Conventional impressions for orthodontic study models of the dental arches were taken using an alginate impression material (Hydrogum®, Zhermack Spa, Badia Polesine, Rovigo, Italy). Fifteen days later, digital impressions of both arches were acquired using an intraoral scanner (CS3600®, Carestream Dental, Rochester, NY, USA). Immediately after impression taking, patients' acceptability, comfort and stress were measured using two questionnaires and the State anxiety scale. Results: Data showed no difference in terms of anxiety and stress; however, patients preferred the use of digital impressions systems instead of conventional impression techniques. Alginate impressions resulted as fast as digital impressions. Conclusions: Digital impressions resulted the most accepted and comfortable impression technique in young orthodontic patients, when compared to conventional techniques.

11.
BMC Oral Health ; 17(1): 149, 2017 Dec 12.
Artículo en Inglés | MEDLINE | ID: mdl-29233132

RESUMEN

BACKGROUND: Intraoral scanners (IOS) are devices for capturing direct optical impressions in dentistry. The purpose of this narrative review on the use of IOS was to: (1) identify the advantages/disadvantages of using optical impressions compared to conventional impressions; (2) investigate if optical impressions are as accurate as conventional impressions; (3) evaluate the differences between the IOS currently available commercially; (4) determine the current clinical applications/limitations in the use of IOS. METHODS: Electronic database searches were performed using specific keywords and MeSH terms. The searches were confined to full-text articles written in English and published in peer-reviewed journals between January 2007 and June 2017. RESULTS: One hundred thirty-two studies were included in the present review; among them, 20 were previous literature reviews, 78 were in vivo clinical studies (6 randomized controlled/crossover trials, 31 controlled/comparative studies; 24 cohort studies/case series; 17 case reports) and 34 were in vitro comparative studies. CONCLUSIONS: Optical impressions reduce patient discomfort; IOS are time-efficient and simplify clinical procedures for the dentist, eliminating plaster models and allowing better communication with the dental technician and with patients; however, with IOS, it can be difficult to detect deep margin lines in prepared teeth and/or in case of bleeding, there is a learning curve, and there are purchasing and managing costs. The current IOS are sufficiently accurate for capturing impressions for fabricating a whole series of prosthetic restorations (inlays/onlays, copings and frameworks, single crowns and fixed partial dentures) on both natural teeth and implants; in addition, they can be used for smile design, and to fabricate posts and cores, removable partial prostheses and obturators. The literature to date does not support the use of IOS in long-span restorations with natural teeth or implants. Finally, IOS can be integrated in implant dentistry for guided surgery and in orthodontics for fabricating aligners and custom-made devices.


Asunto(s)
Técnica de Impresión Dental/instrumentación , Humanos
12.
Eur J Oral Implantol ; 10(4): 373-390, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-29234745

RESUMEN

PURPOSE: To evaluate the influence of at least three abutment disconnections in conventional loaded implants against placement of a definitive abutment in immediately non-occlusal loaded implants on hard and soft tissue changes. A secondary aim was to evaluate whether the presence of less than 2 mm of keratinised mucosa is associated with increased peri-implant marginal bone loss and soft tissue recessions. MATERIALS AND METHODS: Eighty patients requiring one single crown or one fixed partial prosthesis supported by a maximum of three implants were randomised, after implants were placed with more than 35 Ncm, according to a parallel group design to receive definitive abutments that were loaded immediately (definitive abutment or immediate loading group) or transmucosal abutments, which were delayed loaded after 3 months and removed at least three times: 1. At impression taking (3 months after implant placement); 2. When checking the zirconium core on titanium abutments at single crowns or the fitting the metal structure at prostheses supported by multiple implants; 3. At delivery of the definitive prostheses (repeated disconnection or conventional loading group). Patients were treated at four centres and each patient contributed to the study, with only one prosthesis followed for 3 years after initial loading. Outcome measures were: prosthesis failures, implant failures, complications, pink aesthetic score (PES), buccal recessions, patient satisfaction, peri-implant marginal bone level changes and height of the keratinised mucosa. RESULTS: Forty patients were randomly allocated to each group according to a parallel group design. Six patients from the definitive abutment group dropped out or died, and one left from the repeated disconnection group. One implant, from the repeated disconnection group, fractured (difference = 3%; CI 95%: -2%, 8%; P = 1). Four provisional crowns and one definitive single crown had to be remade because of poor fitting, and one definitive crown and one definitive prosthesis because of ceramic and implant fracture, respectively, in the repeated disconnection group vs one provisional prosthesis from the definitive abutment group due to frequent debondings (difference = 15%; CI 95%: 2%, 28%; P = 0.060). Five patients from the definitive abutment group and four patients from the repeated disconnection group were affected by complications (difference = 4%; CI 95%: -11%, 20%; P = 0.725). PES scores assessed at 3 years post-loading were 11.7 (standard deviation = 1.8) mm for the definitive abutment group and 11.3 (1.5) mm for the repeated abutment changes group (difference = 0.4; CI 95%: -0.4, 1.2; P = 0.315). However, there was a difference of 0.26 out of a maximum score of 2 in favour of the definitive abutment group for soft tissue contour only. Buccal recessions at 3 years post-loading amounted to -0.1 (0.8) mm for the definitive abutment group and -0.1 (1.2) mm for the repeated abutment changes group (it was actually a soft tissue gain; difference = 0.01 mm CI 95%: -0.48, 0.50; P = 0.965). All patients declared being very satisfied or satisfied with the function and aesthetics of the prostheses and said they would undergo the same procedure again, with the exception of one patient from the repeated disconnection group who was uncertain regarding function. Mean peri-implant marginal bone loss 3 years after loading was 0.07 (0.18) mm for the definitive abutment group and 0.50 (0.93) mm for the repeated abutment changes group (difference = 0.43 mm; CI 95%: 0.13, 0.74; P = 0.007). The height of keratinised mucosa at 3 years post-loading was 2.8 (1.3) mm for the definitive abutment group and 2.8 (1.6) mm for the repeated abutment changes group (difference = 0.03; CI 95%: -0.67, 0.73; P = .926). Up to 3 years after initial loading there were no statistically significant differences between the two procedures, with the exception of 0.4 mm more marginal bone loss at implants subjected to three abutment disconnections. There were no significantly increased marginal bone loss (difference = 0.1 mm, CI 95%: -0.3, 0.5, P = 0.590) or buccal recessions (difference = 0.1 mm, CI 95%: -0.4, 0.7, P = 0.674) at implants with less than 2 mm of keratinised mucosa at loading. CONCLUSIONS: Three-year post-loading data showed that repeated abutment disconnections significantly increased bone loss of 0.43 mm, but this difference may not be considered clinically relevant; therefore clinicians can use the procedure they find more convenient for each specific patient. Immediately non-occlusally loaded dental implants are a viable alternative to conventional loading and no increased bone loss or buccal recessions were noticed at implants with less than 2 mm of keratinised mucosa. Conflict of interest statement: This trial was partially funded by Dentsply Sirona Implants, the manufacturer of the implants and other products evaluated in this investigation. However, data belonged to the authors and by no means did the manufacturer interfere with the conduct of the trial or the publication of the results, with the exception of rejecting a proposal to change the protocol, after the trial was started, allowing the use of indexed abutments.


Asunto(s)
Pilares Dentales , Carga Inmediata del Implante Dental , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Persona de Mediana Edad , Factores de Tiempo , Resultado del Tratamiento
13.
Nanomaterials (Basel) ; 7(9)2017 Sep 16.
Artículo en Inglés | MEDLINE | ID: mdl-28926948

RESUMEN

We report observations of field emission from self-catalyzed GaAs nanowires grown on Si (111). The measurements were taken inside a scanning electron microscope chamber with a nano-controlled tungsten tip functioning as anode. Experimental data were analyzed in the framework of the Fowler-Nordheim theory. We demonstrate stable current up to 10-7 A emitted from the tip of single nanowire, with a field enhancement factor ß of up to 112 at anode-cathode distance d = 350 nm. A linear dependence of ß on the anode-cathode distance was found. We also show that the presence of a Ga catalyst droplet suppresses the emission of current from the nanowire tip. This allowed for the detection of field emission from the nanowire sidewalls, which occurred with a reduced field enhancement factor and stability. This study further extends GaAs technology to vacuum electronics applications.

14.
Nanomaterials (Basel) ; 7(7)2017 Jun 27.
Artículo en Inglés | MEDLINE | ID: mdl-28654012

RESUMEN

We study the effect of temperature and light on the I-V and C-V characteristics of a graphene/silicon Schottky diode. The device exhibits a reverse-bias photocurrent exceeding the forward current and achieves a photoresponsivity as high as 2.5 A / W . We show that the enhanced photocurrent is due to photo-generated carriers injected in the graphene/Si junction from the parasitic graphene/SiO2/Si capacitor connected in parallel to the diode. The same mechanism can occur with thermally generated carriers, which contribute to the high leakage current often observed in graphene/Si junctions.

15.
Nanotechnology ; 28(21): 214002, 2017 May 26.
Artículo en Inglés | MEDLINE | ID: mdl-28471746

RESUMEN

We study electrical transport properties in exfoliated molybdenum disulfide (MoS2) back-gated field effect transistors at low drain bias and under different illumination intensities. It is found that photoconductive and photogating effect as well as space charge limited conduction can simultaneously occur. We point out that the photoconductivity increases logarithmically with the light intensity and can persist with a decay time longer than 104 s, due to photo-charge trapping at the MoS2/SiO2 interface and in MoS2 defects. The transfer characteristics present hysteresis that is enhanced by illumination. At low drain bias, the devices feature low contact resistance of [Formula: see text] ON current as high as [Formula: see text] 105 ON-OFF ratio, mobility of ∼1 cm2 V-1 s-1 and photoresponsivity [Formula: see text].

16.
Eur J Oral Implantol ; 10(1): 57-72, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28327695

RESUMEN

PURPOSE: To evaluate the influence of at least three abutment changes in conventionally loaded implants against placement of a definitive abutment in immediately non-occlusal loaded implants on hard and soft tissue changes. MATERIALS AND METHODS: Eighty patients requiring one single crown or one fixed partial prosthesis supported by a maximum of three implants were randomised, after implants were placed with more than 35 Ncm, according to a parallel group design to receive definitive abutments which were loaded immediately (definitive abutment or immediate loading group) or transmucosal abutments. These were delayed loaded after 3 months and were removed at least three times: 1) at impression taking (3 months after implant placement); 2) when checking the zirconium core on titanium abutments at single crowns or the fitting the metal structure at prostheses supported by multiple implants; 3) at delivery of the definitive prostheses (repeated disconnection or conventional loading group). Patients were treated in four centres and each patient contributed to the study with only one prosthesis followed for 1 year after initial loading. Outcome measures were: prosthesis failures, implant failures, complications, pink esthetic score (PES), buccal recessions, patient satisfaction, peri-implant marginal bone level changes and height of the keratinised mucosa. RESULTS: Forty patients were randomly allocated to each group according to a parallel group design. Two patients dropped out from the definitive abutment group but no implant failed. Four provisional and one definitive single crowns had to be remade (due of misfitting) and one definitive crown (due to ceramic fracture) in the repeated disconnection group versus one provisional prosthesis of the immediate loading group due to frequent debondings (difference = 12%; CI95%: 0%, 25%; P = 0.109). Eight patients were affected by complications: four patients from each group (difference = 1%; CI95%: -13%, 14%; P = 1). PES scores assessed at 1 year post-loading were 11.4 (1.5) mm for the definitive abutment group and 11.0 (2.0) mm for the repeated abutment changes group (difference = 0.4; CI95%: -0.4, 1.2; P = 0.289). Buccal recessions at 1 year post-loading amounted to 0.07 (0.35) mm for the definitive abutment group and 0.12 (0.65) mm for the repeated abutment changes group (actually it was a soft tissue gain; difference = 0.05 CI 95%: -0.19, 0.29; P = 0.659). All patients declared to be very satisfied or satisfied with the function and aesthetics of the prostheses and would undergo the same procedure again. Mean peri-implant marginal bone loss at 1 year after loading was 0.06 (0.12) mm for the definitive abutment group and 0.23 (0.49) mm for the repeated abutment changes group (difference = -0.16; CI95%: -0.33,-0.00; P = 0.046). The height of the keratinised mucosa at 1 year post-loading was 2.8 (1.5) mm for the definitive abutment group and 2.8 (1.7) mm for the repeated abutment changes group (difference = -0.0; CI 95%: -0.8, 0.7); P = 0.966. Up to 1 year after initial loading, there were no statistically significant differences between the two procedures, with the exception of 0.16 mm more marginal bone loss at implants subjected to three abutment removals. CONCLUSIONS: One-year post-loading data showed that repeated abutment changes significantly increased bone loss of 0.16, but this difference cannot be considered clinically relevant, therefore clinicians can use the procedure they find more convenient for their specific patient. In addition, immediately non-occlusally loaded dental implants are a viable alternative to conventional loading. Conflict-of-interest statement: This trial was partially funded by Dentsply Sirona Implants, the manufacturer of the implants and other products evaluated in this investigation. However, data belonged to the authors and by no means did the manufacturer interfere with the conduct of the trial or the publication of the results with exception of rejecting the proposal of changing the protocol, after the trial was started, allowing the use of indexed abutments.


Asunto(s)
Diseño de Implante Dental-Pilar , Implantación Dental Endoósea/métodos , Adulto , Anciano , Anciano de 80 o más Años , Pérdida de Hueso Alveolar/etiología , Coronas , Prótesis Dental de Soporte Implantado , Femenino , Humanos , Carga Inmediata del Implante Dental , Masculino , Persona de Mediana Edad , Satisfacción del Paciente
17.
Biomed Res Int ; 2017: 4152506, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28280731

RESUMEN

Aim. To evaluate the effects of fixture design and surface on the early bone formation around immediately loaded implants inserted in the human posterior maxilla. Materials and Methods. Ten totally edentulous subjects received two transitional implants: one tapered implant with knife-edge threads/nanostructured calcium-incorporated surface (test: Anyridge®, Megagen, Gyeongbuk, South Korea) and one cylindrical implant with self-tapping threads/sandblasted surface (control: EZPlus®, Megagen). The implants were placed according to a split-mouth design and immediately loaded to support an interim complete denture; after 8 weeks, they were removed for histologic/histomorphometric analysis. The bone-to-implant contact (BIC%) and the bone density (BD%) were calculated. The Wilcoxon test was used to evaluate the differences. Results. With test implants, a mean BIC% and BD% of 35.9 (±9.1) and 31.8 (±7.5) were found. With control implants, a mean BIC% and BD% of 29.9 (±7.6) and 32.5 (±3.9) were found. The mean BIC% was higher with test implants, but this difference was not significant (p = 0.16). Similar BD% were found in the two groups (p = 0.9). Conclusions. In the posterior maxilla, under immediate loading conditions, implants with a knife-edge thread design/nanostructured calcium-incorporated surface seem to increase the peri-implant endosseous healing properties, when compared to implants with self-tapping thread design/sandblasted surface.


Asunto(s)
Implantes Dentales , Diseño de Prótesis Dental , Maxilar/cirugía , Osteogénesis , Adulto , Anciano , Densidad Ósea , Femenino , Humanos , Masculino , Persona de Mediana Edad , Propiedades de Superficie
18.
Clin Oral Investig ; 21(8): 2603-2611, 2017 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-28154996

RESUMEN

OBJECTIVE: The aim of this randomized, controlled histologic/histomorphometric study was to compare the early bone formation around immediately loaded implants with nanostructured calcium-incorporated (NCI) and machined (MA) surface, placed in the human posterior maxilla. MATERIALS AND METHODS: Fifteen fully edentulous patients (six males; nine females; mean age 57.9 ± 6.7 years) were selected for this study. Each patient was installed with two temporary transmucosal implants, with different surfaces: one NCI (test) and one MA (control) implant. All temporary implants were placed in the posterior maxilla, according to a split-mouth design, to help to support an interim complete maxillary denture. After 8 weeks, all temporary transmucosal implants were retrieved for histologic/histomorphometric evaluation. The bone-to-implant contact (BIC%) and the bone density (BD%) were calculated. The Wilcoxon matched-pairs signed-rank test was used to evaluate differences (BIC%, BD%) between the surfaces. The level of significance was set at 0.05. RESULTS: Eight weeks after placement, 24 clinically stable implants (12 test, 12 control) were subjected to histologic/histomorphometric evaluation. In the MA implants, the histomorphometric evaluation revealed a mean BIC(±SD)% and BD(±SD)% of 21.2(±4.9)% and 29.8(±7.8)%, respectively. In the NCI implants, the histomorphometric analysis revealed a mean BIC(±SD)% and BD(±SD)% of 39.7(±8.7)% and 34.6(±7.2)%, respectively. A statistically significant difference was found between the two surfaces with regard to BIC% (p < 0.001), while no significant difference was found with regard to BD% (p = 0.09). CONCLUSIONS: The NCI surface seems to increase the peri-implant endosseous healing properties in the native bone of the posterior maxilla, under immediate loading conditions, when compared with the MA surface. CLINICAL RELEVANCE: Under immediate loading conditions in the human posterior maxilla, the nanostructured calcium-incorporated surface has led to better histologic and histomorphometric results than the machined surface; therefore, the clinical use of implants with nanostructured calcium-incorporated surface may be beneficial in the posterior maxilla, under immediate loading protocol.


Asunto(s)
Interfase Hueso-Implante , Calcio/química , Implantes Dentales , Carga Inmediata del Implante Dental , Arcada Edéntula/rehabilitación , Maxilar/cirugía , Oseointegración/fisiología , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Nanoestructuras , Propiedades de Superficie
19.
Artículo en Inglés | MEDLINE | ID: mdl-27977820

RESUMEN

The aim of this prospective multicenter study was to evaluate the outcomes of single implants subjected to immediate functional loading. Inclusion criteria were single-tooth placement in postextraction sockets or fully healed sites, and sufficient bone height and width to place an implant of at least 3.5 × 10.0 mm. All implants were functionally loaded immediately after placement and followed for 2 years. Outcome measures were implant survival, complications, and peri-implant marginal bone loss (MBL). A total of 57 implants (38 maxilla, 19 mandible) were placed in 46 patients (23 men, 23 women, aged 18-73 years). Of these, 10 implants were placed in postextraction sockets. One implant failed, in a healed site, giving a patient-based overall 2-year survival rate of 97.6%. The incidence of biologic complications was 1.8%; prosthetic complications amounted to 7.5%. The peri-implant MBL was 0.37 ± 0.22 mm (healed sites: 0.4 mm ± 0.22; postextraction sockets: 0.3 mm ± 0.22). The immediate functional loading of single implants seems to represent a safe and successful procedure. Long-term follow-up studies on a larger sample of patients are needed to confirm these results.


Asunto(s)
Implantes Dentales de Diente Único , Carga Inmediata del Implante Dental , Adolescente , Adulto , Anciano , Pérdida de Hueso Alveolar/epidemiología , Adaptación Marginal Dental , Fracaso de la Restauración Dental , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Extracción Dental , Alveolo Dental/cirugía , Resultado del Tratamiento
20.
Eur J Oral Implantol ; 9(4): 367-379, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27990505

RESUMEN

PURPOSE: To evaluate the safety and clinical effectiveness of a novel dental implant system (GENESIS Implant System, Keystone Dental, Massachusetts, USA) using another dental implant system by the same manufacturer as a control (PRIMA Implant System, Keystone Dental). MATERIALS AND METHODS: A total of 53 patients requiring at least two single crowns had their sites randomised according to a split-mouth design to receive both implant systems at six centres. If implants could be placed with a torque superior to 40 Ncm they were to be loaded immediately with provisional crowns, otherwise after 3 months of submerged healing. Provisional crowns were replaced by definitive crowns 4 months after initial loading, when the follow-up period for the initial part of this study was completed. Outcome measures were crown/implant failures, complications, pink esthetic score (PES), peri-implant marginal bone level changes, plaque score, marginal bleeding, patients and preference of the clinician. RESULTS: In total 53 PRIMA and 53 GENESIS implants were placed. Three patients dropped out but all of the remaining patients were followed up to 4-months post-loading. No PRIMA implant failed whereas four GENESIS implants failed. Only two complications were reported for PRIMA implants. There were no statistically significant differences for crown/implant failures (difference in proportions = 0.080; P (McNemar test) = 0.125) and complications (difference in proportions = -0.04; P (McNemar test) = 0.500) between the implant systems. There were no differences at 4-months post-loading for plaque (difference = -0.54, 95% CI: -3.01 to 1.93; P (Paired t-test) = 0.660), marginal bleeding (difference = -3.8, 95% CI: -7.63 to 0.019; P (Paired t-test) = 0.051), PES (difference = 0.47, 95% CI: -0.56 to 1.50; P (Paired t-test) = 0.365) and marginal bone level changes (difference in mm = -0.04, 95% CI: -0.33 to 0.26; P (Paired t-test) = 0.795). The majority of the patients (46) had no preference regarding the two implant systems evaluated. Three operators preferred GENESIS implants, two had no preference and one preferred GENESIS in medium and soft bone and PRIMA in hard bone. CONCLUSIONS: No statistically significant differences were observed between the systems' implant types, although four GENESIS implants failed versus none of the PRIMA type. Longer follow-ups of wider patient populations are needed to better understand whether there is an effective advantage with one of the two implant designs. Conflict-of-interest statement: This research project was originally funded by Keystone Italia, Dental spa (Verona, Italy), the manufacturer of the implants evaluated in this investigation. However, when Keystone Italia received the data of the present manuscript, they refused to honour the financial agreement for the present publication. Therefore, no further follow-ups of this trial will be considered. A legal action was initiated against Keystone Italia. The data belonged to the authors and by no means was the manufacturer allowed to interfere with the conduct of the trial or the publication of the results.


Asunto(s)
Implantes Dentales , Carga Inmediata del Implante Dental , Coronas , Diseño de Prótesis Dental , Humanos , Factores de Tiempo
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