Nonanimal stabilized hyaluronic acid for tissue augmentation of the dorsal hands: a prospective study on 38 patients

BACKGROUND Often ignored, hands are one of the most telltale signs of aging. This prospective study was initiated to evaluate the effect of subcutaneous hyaluronic acid (HA) injections in aging hands, with special attention to complications and long-term outcomes. METHODS Between January 2010 and December 2010, a total of 38 patients with skin phototypes II-IV and between 58 and 76 years old were treated with HA injection for aging hands. The quantity of injection never exceeded 1.0-1.5 ml HA per hand. A clinical follow-up was performed at 2 weeks, 4 weeks, 3 months, and 6 months after injection. Complications were reviewed for the whole series. At the first follow-up, 2 weeks after the procedure, ultrasound was carried out to determine if additional filling material was required. At each follow-up, patients were asked to fill out a satisfaction questionnaire. RESULTS Nine patients developed slight ecchymosis that disappeared after 1 week. No other complications were seen in the series. Pain during the injection and discomfort after the procedure were minimal. At the 2-week follow-up, after ultrasound control, nine patients received a complementary injection. At each follow-up, overall patient satisfaction was high and was validated by clearance of rhytids, veins, bony prominences, and dermal and subcutaneous atrophy. CONCLUSION Skin revitalization with injectable HA can improve the clinical appearance of the back of the hands. However, this therapy requires knowledge of the possible complications and their remediation as well as knowledge and respect of injected doses. Moreover, despite excellent results at each follow-up, the results of our series are not as good after 6 months, and a longer follow-up would be needed to determine if this procedure provides long-lasting benefit. LEVEL OF EVIDENCE III This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Short-term Functional and Patient Outcome of the Bi-cruciate Stabilized Total Knee Replacement: Prospective Consecutive Case-series

Background: Total knee replacement is the gold standard treatment for patients suffering from advanced symptomatic knee osteoarthritis. The main goals of knee prosthetics are pain reduction and restoration of knee motion. The new prostheses on the market such as the bi-cruciate stabilized Journey knee implant, promise a reconstruction of total physiological function of the knee with physiological range of motion and therefore high patient satisfaction. Purpose: The aim of this study was to analyze the patient-based Knee Injury and Osteoarthritis Outcome Score (KOOS) outcome after total knee replacement with new physiological bi-cruciate stabilized Journey knee prosthesis. Study Design: Prospective, consecutive case-series. Patients: Ninety nine patients, who received bi-cruciate stabilized Journey total knee prosthesis between January 1st 2006 and May 31st 2012, were included in the study. A single surgeon operated all patients. There were 61.1% females and the overall average age was 68 years (range 41-83 years). Left knee was replaced in 55.6%. Methods: The patients filled in KOO’s questionnaire pre- and 1 year postoperative. Range of motion (ROM) was studied preoperatively and at 1-year follow-ups. The pre- and postoperative KOOS subscores and ROM were compared using the Wilcoxon signed rank test. Results: There are significant improvements of all KOOS subscores. Ninety percent of patients have reached the minimum clinically relevant 10 points in symptoms, 94.5% in pain, 94.5% in activities of daily living, 84.9% in sport and recreation, and 90% in knee related quality of life. Postoperative, the average passive ROM was 131° (range 110-145°) and the average active ROM 122° (range 105-135°). The highest correlation coefficients ROM and the KOOS were observed for the activity and pain subscores. Very low or no correlation was seen for the sport subscore. Conclusions: Bi-cruciate stabilized knee prosthetic offers a solid outcome 1 year postoperative based on the results measured with the KOOS evaluation questionnaire. The Patients showed a generalized improvement in all domains measured in the KOOS of minimally 35, and up to over 52 points, what can be described as statistically significant. Patients described the level of functionality close to double compared to the preoperative status.

Acid and Alkaline Etching of Sandblasted Zirconia Implants: A Histomorphometric Study in Miniature Pigs.

BACKGROUND: Zirconia (ZrO2 ) has received interest as a dental material; however, little information is available on the impact of surface modifications on the osseointegration of zirconia implants. PURPOSE: The aim of the present study was to determine the effect of acid or alkaline etching of sandblasted ZrO2 implants on bone apposition in vivo. METHODS: Cylindrical ZrO2 implants with two circumferential grooves were placed in the maxilla of 12 miniature pigs. Biopsies were harvested after 1, 2, 4, and 8 weeks of healing. Undecalcified toluidine blue-stained ground sections were produced. The bone-to-implant contact, the bone area, and the presence of multinucleated giant cells were determined by histomorphometry. An uncorrected explorative statistical analysis was performed. RESULTS: Acid etching but not alkaline etching of sandblasted ZrO2 implants caused more bone-to-implant contact than sandblasted ZrO2 implants. The bone area was unaffected by the surface modifications. Acid and alkaline etching both increased the formation of multinucleated giant cells at the implant surface. CONCLUSIONS: This study provides a scientific basis to further investigate the impact of acid etching of sandblasted ZrO2 implants on osseointegration and the role of multinucleated giant cells in this process.

Technical complications and failures of zirconia-based prostheses supported by implants followed up to 7 years: a case series.

PURPOSE To evaluate technical complications and failures of zirconia-based fixed prostheses supported by implants. MATERIALS AND METHODS Consecutive patients received zirconia-based single crowns (SCs) and fixed dental prostheses (FDPs) on implants in a private clinical setting between 2005 and 2010. One dentist performed all surgical and prosthetic procedures, and one master technician performed and coordinated all laboratory procedures. One-piece computer-aided design/ computer-assisted manufacture technology was used to fabricate abutments and frameworks, which were directly connected at the implant level, where possible. All patients were involved in a recall maintenance program and were finally reviewed in 2012. Data on framework fractures, chipping of veneering ceramics, and other technical complications were recorded. The primary endpoint was failure of the prostheses, ie, the need for a complete remake. A life table analysis was calculated. RESULTS A total of 289 implants supported 193 zirconia-based prostheses (120 SCs and 73 FDPs) in 127 patients (51 men, 76 women; average age: 62.5 ± 13.4 years) who were reviewed in 2012. Twenty-five (13%) prostheses were cemented on 44 zirconia abutments and 168 (87%) prostheses were screw-retained directly at the implant level. Fracture of 3 frameworks (1 SC, 2 FDPs) was recorded, and significant chipping resulted in the remake of 3 prostheses (1 SC, 2 FDPs). The 7-year cumulative survival rate was 96.4% ± 1.99%. Minor complications comprised 5 loose screws (these were retightened), small chips associated with 3 prostheses (these were polished), and dislodgement of 3 prostheses (these were recemented). Overall, 176 prostheses remained free of technical problems. CONCLUSIONS Zirconia-based prostheses screwed directly to implants are clinically successful in the short and medium term.

Long-term storage affects adhesion between titanium and zirconia using resin cements.

PURPOSE To determine the impact of long-term storage on adhesion between titanium and zirconia using resin cements. MATERIALS AND METHODS Titanium grade 4 blocks were adhesively fixed onto zirconia disks with four resin cements: Panavia F 2.0 (Kuraray Europe), GC G-Cem (GC Europe), RelyX Unicem (3M ESPE), and SmartCem 2 (Dentsply DeguDent). Shear bond strength was determined after storage in a water bath for 24 h, 16, 90, and 150 days at 37°C, and after 6000 cycles between 5°C and 55°C. Fracture behavior was evaluated using scanning electron microscopy. RESULTS After storage for at least 90 days and after thermocycling, GC G-Cem (16.9 MPa and 15.1 MPa, respectively) and RelyX Unicem (10.8 MPa and 15.7 MPa, respectively) achieved higher shear bond strength compared to SmartCem 2 (7.1 MPa and 4.0 MPa, respectively) and Panavia F2 (4.1 MPa and 7.4 MPa, respectively). At day 150, GC G-Cem and RelyX Unicem caused exclusively mixed fractures. SmartCem 2 and Panavia F2 showed adhesive fractures in one-third of the cases; all other fractures were of mixed type. After 24 h (GC G-Cem: 26.0, RelyX Unicem: 20.5 MPa, SmartCem 2: 16.1 MPa, Panavia F2: 23.6 MPa) and 16 days (GC G-Cem: 12.8, RelyX Unicem: 14.2 MPa, SmartCem 2: 9.8 MPa, Panavia F2: 14.7 MPa) of storage, shear bond strength was similar among the four cements. CONCLUSION Long-term storage and thermocycling differentially affects the bonding of resin cement between titanium and zirconia.

Short-term functional versus patient-reported outcome of the bicruciate stabilized total knee arthroplasty: prospective consecutive case series

BACKGROUND The main goals of the standard treatment for advanced symptomatic knee osteoarthritis, total knee arthroplasty (TKA), are pain reduction and restoration of knee motion.The aim of this study was to analyse the outcome of the patient-based Knee Injury and Osteoarthritis Outcome Score (KOOS), and the surgeon-based Knee Society Score (KSS) and its Knee Score (KS) and Knee Functional Score (KFS) components after (TKA) using the Journey knee prosthesis, and to assess the correlation of these scores with range of motion (ROM). METHODS In a prospective case series study between August 1st 2008 and May 31st 2011, 99 patients, all operated by a single surgeon, received Journey bicruciate stabilized total knee prostheses. The female/male ratio was 53/34, the mean patient age at surgery was 68 years (range 41-83 years), and the left/right knee ratio was 55/44. The KOOS, range of motion, and KS and KFS were obtained preoperatively and at 1-year follow-up. The pre- and postoperative levels of the outcome measures were compared using the Wilcoxon signed-rank test. Correlation between ROM and patient outcomes was analysed with the Spearman coefficient. RESULTS All KOOS subscores improved significantly. Ninety percent of patients improved by at least the minimum clinically relevant difference of 10 points in stiffness and other symptoms, 94.5% in pain, 94.5% in activities of daily living, 84.9% in sports and recreation, and 90% in knee-related quality of life. The mean passive and active ROM improved from 122.4° (range 90-145°) and 120.4° (range 80-145°) preoperatively to 129.4° (range 90-145°) and 127.1° (range 100-145°) postoperatively. The highest correlation coefficients for ROM and KOOS were observed for the activity and pain subscores. Very low or no correlation was seen for the sport subscore.There was a significant and clinically relevant improvement of KSS (preop/postop 112.2/174.5 points), and its KS (preop/postop 45.6/86.8 points) and KFS (preop/postop 66.6/87.8 points) components. CONCLUSIONS The Journey bicruciate stabilized knee prosthesis showed good 1-year postoperative results in terms of both functional and patient-based outcome. However, higher knee ROM correlates only moderately with patient-based outcome, implying that functionality afforded by the Journey bicruciate TKA is not equivalent to patient satisfaction.

Peri-implant soft tissue colour around titanium and zirconia abutments: a prospective randomized controlled clinical study

OBJECTIVES To objectively determine the difference in colour between the peri-implant soft tissue at titanium and zirconia abutments. MATERIALS AND METHODS Eleven patients, each with two contralaterally inserted osteointegrated dental implants, were included in this study. The implants were restored either with titanium abutments and porcelain-fused-to-metal crowns, or with zirconia abutments and ceramic crowns. Prior and after crown cementation, multi-spectral images of the peri-implant soft tissues and the gingiva of the neighbouring teeth were taken with a colorimeter. The colour parameters L*, a*, b*, c* and the colour differences ΔE were calculated. Descriptive statistics, including non-parametric tests and correlation coefficients, were used for statistical analyses of the data. RESULTS Compared to the gingiva of the neighbouring teeth, the peri-implant soft tissue around titanium and zirconia (test group), showed distinguishable ΔE both before and after crown cementation. Colour differences around titanium were statistically significant different (P = 0.01) only at 1 mm prior to crown cementation compared to zirconia. Compared to the gingiva of the neighbouring teeth, statistically significant (P < 0.01) differences were found for all colour parameter, either before or after crown cementation for both abutments; more significant differences were registered for titanium abutments. Tissue thickness correlated positively with c*-values for titanium at 1 mm and 2 mm from the gingival margin. CONCLUSIONS Within their limits, the present data indicate that: (i) The peri-implant soft tissue around titanium and zirconia showed colour differences when compared to the soft tissue around natural teeth, and (ii) the peri-implant soft tissue around zirconia demonstrated a better colour match to the soft tissue at natural teeth than titanium.

Stiffness, Strength, and Failure Modes of Implant-Supported Monolithic Lithium Disilicate Crowns: Influence of Titanium and Zirconia Abutments

PURPOSE The objective of this study was to evaluate stiffness, strength, and failure modes of monolithic crowns produced using computer-aided design/computer-assisted manufacture, which are connected to diverse titanium and zirconia abutments on an implant system with tapered, internal connections. MATERIALS AND METHODS Twenty monolithic lithium disilicate (LS2) crowns were constructed and loaded on bone level-type implants in a universal testing machine under quasistatic conditions according to DIN ISO 14801. Comparative analysis included a 2 × 2 format: prefabricated titanium abutments using proprietary bonding bases (group A) vs nonproprietary bonding bases (group B), and customized zirconia abutments using proprietary Straumann CARES (group C) vs nonproprietary Astra Atlantis (group D) material. Stiffness and strength were assessed and calculated statistically with the Wilcoxon rank sum test. Cross-sections of each tested group were inspected microscopically. RESULTS Loaded LS2 crowns, implants, and abutment screws in all tested specimens (groups A, B, C, and D) did not show any visible fractures. For an analysis of titanium abutments (groups A and B), stiffness and strength showed equally high stability. In contrast, proprietary and nonproprietary customized zirconia abutments exhibited statistically significant differences with a mean strength of 366 N (Astra) and 541 N (CARES) (P < .05); as well as a mean stiffness of 884 N/mm (Astra) and 1,751 N/mm (CARES) (P < .05), respectively. Microscopic cross-sections revealed cracks in all zirconia abutments (groups C and D) below the implant shoulder. CONCLUSION Depending on the abutment design, prefabricated titanium abutment and proprietary customized zirconia implant-abutment connections in conjunction with monolithic LS2 crowns had the best results in this laboratory investigation.

Management of a complication with a fractured zirconia implant abutment in the esthetic zone

Technical complications in implant prosthetic cases represent a major challenge in dentistry. This case report describes minimally invasive management to recover an implant with a fractured remnant of a zirconia abutment, including provisional rehabilitation during a sequential treatment protocol in the esthetic zone. A patient was treated with a screw-retained one-piece implant-supported reconstruction made of a customized zirconia abutment with direct ceramic veneering in the maxillary right central incisor position. During the prosthetic try-in, a fracture in the apical portion of the abutment was evident. The first rescue attempt led to fracture of the retrieval instrument. Immediately, an individualized wired construction was applied to bond the existing fractured reconstruction to the neighboring teeth to maintain the peri-implant mucosal architecture. Because the implant screw canal was blocked, a customized round bur had to be manufactured and was placed in the implant axis with a specific bracket tool from the service set to protect the interior implant threads. Then, the drills of the service set were guided by the newly created access to remove the fractured remnants. The implant screw was retapped and the area rinsed with chlorhexidine solution. All remnants were removed without the need for surgical intervention. Neither the implant connection nor the bone-to-implant interface was damaged. The stepwise treatment approach with the customized round bur combined with the system-specific drills of the service set saved the blocked implant so that the patient could be successfully rehabilitated with a new implant reconstruction.

Zirconia-Based Screw-Retained Prostheses Supported by Implants: A Retrospective Study on Technical Complications and Failures

BACKGROUND Little information is yet available on zirconia-based prostheses supported by implants. PURPOSE To evaluate technical problems and failures of implant-supported zirconia-based prostheses with exclusive screw-retention. MATERIAL AND METHODS Consecutive patients received screw-retained zirconia-based prostheses supported by implants and were followed over a time period of 5 years. The implant placement and prosthetic rehabilitation were performed in one clinical setting, and all patients participated in the maintenance program. The treatment comprised single crowns (SCs) and fixed dental prostheses (FDPs) of three to 12 units. Screw-retention of the CAD/CAM-fabricated SCs and FDPs was performed with direct connection at the implant level. The primary outcome was the complete failure of zirconia-based prostheses; outcome measures were fracture of the framework or extensive chipping resulting in the need for refabrication. A life table analysis was performed, the cumulative survival rate (CSR) calculated, and a Kaplan-Meier curve drawn. RESULTS Two hundred and ninety-four implants supported 156 zirconia-based prostheses in 95 patients (52 men, 43 women, average age 59.1 ± 11.7 years). Sixty-five SCs and 91 FDPs were identified, comprising a total of 441 units. Fractures of the zirconia framework and extensive chipping resulted in refabrication of nine prostheses. Nearly all the prostheses (94.2%) remained in situ during the observation period. The 5-year CSR was 90.5%, and 41 prostheses (14 SCs, 27 FDPs) comprising 113 units survived for an observation time of more than 5 years. Six SCs exhibited screw loosening, and polishing of minor chipping was required for five prostheses. CONCLUSIONS This study shows that zirconia-based implant-supported fixed prostheses exhibit satisfactory treatment outcomes and that screw-retention directly at the implant level is feasible.

Kernel bandwidth estimation for moving object detection in non-stabilized cameras

The evolution of the television market is led by 3DTV technology, and this tendency can accelerate during the next years according to expert forecasts. However, 3DTV delivery by broadcast networks is not currently developed enough, and acts as a bottleneck for the complete deployment of the technology. Thus, increasing interest is dedicated to ste-reo 3DTV formats compatible with current HDTV video equipment and infrastructure, as they may greatly encourage 3D acceptance. In this paper, different subsampling schemes for HDTV compatible transmission of both progressive and interlaced stereo 3DTV are studied and compared. The frequency characteristics and preserved frequency content of each scheme are analyzed, and a simple interpolation filter is specially designed. Finally, the advantages and disadvantages of the different schemes and filters are evaluated through quality testing on several progressive and interlaced video sequences.

Electrophoretic Deposition of Transparent ZnO Thin Films from Highly Stabilized Colloidal Suspensions

The parameters that control the stability of ZnO-nanoparticles suspensions and their deposition by electrophoretic deposition were studied, so as to organize the assembly and compaction of nanoparticles. The addition of cationic polyelectrolyte - Polyethylenimine (PEI) - with different molecular weights was investigated, in order to study their effectiveness and the influence of the molecular weight of the organic chain on suspensions dispersion. It was found that PEI with the highest molecular weight provided better dispersion conditions. Cathodic EPD was performed under previously optimized suspensions conditions and over electropolished stainless steel substrates. Experimental results showed that the EPD process in these conditions allows obtaining dense transparent ZnO thin films. Deposition times and intensities were optimized by analyzing the resulting thin films characteristics. Finally, the deposits were characterized by FE-SEM, AFM, and different spectroscopic techniques.

Relationship between residual stresses and mechanical behavior in ceramic composites

En este trabajo, materiales de tipo alúmina/Y-TZP (ZrO2 tetragonal, estabilizada con 3 mol. % Y2O3), como sistema cerámico popular por sus mejoradas propiedades mecánicas en comparación con las cerámicas de alúmina puras, han sido estudiados en términos de propiedades mecánicas y tensiones residuales. El novedoso método de colado en cinta, consistente en el apilamiento de cintas de cerámica verde a temperatura ambiente y el uso de bajas presiones, se ha escogido para la presente investigación con el fin de poder aprovechar al máximo el futuro desarrollo de materiales laminados de alúmina-óxido de circonio. Se han determinado las propiedades de los materiales obtenidos por este nuevo método de procesamiento comparándolas con las de los materiales obtenidos por “slip casting”, con el fin de analizar si el método propuesto afecta a la microestructura y, por tanto, a las propiedades mecánicas y tensiones residuales propias de estos materiales. Para analizar la idoneidad del proceso de fabricación, utilizado para evitar la presencia de discontinuidades en las intercaras entre las láminas así como otros fenómenos que puedan interferir con las propiedades mecánicas, se estudiaron materiales cerámicos con la misma composición en cintas. Por otra parte también se analizó el efecto de la adición de óxido de circonio sobre la aparición de tensiónes residuales en cerámicas Al2O3/Y-TZP, teniendo en cuenta su notable influencia sobre las propiedades microestructurales y mecánicas de los materiales, así como el requisito de co-sinterización de capas con diferentes materiales compuestos en materiales laminados. La caracterización del material incluye la determinación de la densidad, el análisis de la microestructura, la obtención de las propiedades mecánicas (módulo de elasticidad, dureza, resistencia a la flexión y tenacidad de fractura) así como de las tensiones residuales. En combinación con otros métodos de medida tradicionales, la nanoindentación también se empleó como una técnica adicional para la medida del módulo de elasticidad y de la dureza. Por otro lado, diferentes técnicas de difracción con neutrones, tanto las basadas en longitud de onda constante (CW) como en tiempo de vuelo (TOF), han sido empleadas para la medición fiable de la deformación residual a través del grosor en muestras a granel. Las tensiones residuales fueron determinadas con elevada precisión, aplicando además métodos de análisis apropiados, como por ejemplo el refinamiento de Rietveld. Las diferentes fases en cerámicas sinterizadas, especialmente las de zirconia, se examinaron con detalle mediante el análisis de Rietveld, teniendo en cuenta el complicado polimorfismo del Óxido de Zirconio (ZrO2) así como las posibles transformaciones de fase durante el proceso de fabricación. Los efectos del contenido de Y-TZP en combinación con el nuevo método de procesamiento sobre la microestructura, el rendimiento mecánico y las tensiones residuales de los materiales estudiados (Al2O3/Y-TZP) se resumen en el presente trabajo. Finalmente, los mecanismos de endurecimiento, especialmente los relacionados con las tensiones residuales, son igualmente discutidos. In present work, Alumina/Y-TZP (tetragonal ZrO2 stabilized with 3 mol% Y2O3) materials, as an popular ceramic system with improved mechanical properties compared with the pure alumina ceramics, have been studied in terms of mechanical properties and residual stresses. The novel tape casting method, which involved the stacking of green ceramics tapes at room temperature and using low pressures, is selected for manufacturing and investigation, in order to take full advantage of the future development of alumina-zirconia laminated materials. Features of materials obtained by the new processing method are determined and compared with those of materials obtained by conventional slip casting in a plaster mold, in order to study whether the proposed method of processing affects microstructure and thereby the mechanical properties and residual stresses characteristics of materials. To analyse the adequacy of the manufacturing process used to avoid the presence of discontinuities at the interfaces between the sheets and other phenomena that interfere with the mechanical properties, ceramic materials with the same composition in tapes were investigated. Moreover, the effect of addition of zirconia on residual stress development of Al2O3/Y-TZP ceramics were taken into investigations, considering its significantly influence on the microstructure and mechanical properties of materials as well as the requirement of co-sintering of layers with different composites in laminated materials. The characterization includes density, microstructure, mechanical properties (elastic modulus, hardness, flexure strength and fracture toughness) and residual stresses. Except of the traditional measurement methods, nanoindentation technique was also used as an additional measurement of the elastic modulus and hardness. Neutron diffraction, both the constant-wavelength (CW) and time-of-flight (TOF) neutron diffraction techniques, has been used for reliable through-thickness residual strain measurement in bulk samples. Residual stresses were precisely determined combined with appropriate analysis methods, e.g. the Rietveld refinement. The phase compositions in sintered ceramics especially the ones of zirconia were accurately examined by Rietveld analysis, considering the complex polymorph of ZrO2 and the possible phase transformation during manufacturing process. Effects of Y-TZP content and the new processing method on the microstructure, mechanical performance and residual stresses were finally summarized in present studied Al2O3/Y-TZP materials. The toughening mechanisms, especially the residual stresses related toughening, were theoretically discussed.