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1.
J Oral Implantol ; 49(1): 79-84, 2023 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-34091662

RESUMEN

This prospective study compared the stability of implants placed using piezoelectric surgery (piezo group) and those placed using conventional rotary drills (bur group) during the first 90 days postoperatively. Teeth in the posterior maxillary regions of 21 patients were randomly assigned to 2 groups. The implant stability quotient (ISQ) was measured at days 0, 7, 14, 21, 28, 42, 56, and 90 postoperatively. Twenty-eight of 29 implants were successfully integrated at day 90 (1 implant in the test group was lost). Although both groups showed a significant overall increase in implant stability with time (P < .0001) and a high final mean ISQ value, no statistically significant difference in stability was seen between the groups. The bur group showed greater variance in ISQ values than the piezo group did (P < .001) at all time points. Long-term studies with larger samples are needed to investigate the bone response to the use of piezoelectric surgery for implant preparation.


Asunto(s)
Implantación Dental Endoósea , Implantes Dentales , Humanos , Implantación Dental Endoósea/métodos , Oseointegración/fisiología , Estudios Prospectivos , Estudios Longitudinales
2.
Ann Rheum Dis ; 79(2): 193-201, 2020 02.
Artículo en Inglés | MEDLINE | ID: mdl-31604704

RESUMEN

OBJECTIVES: The Assessment of SpondyloArthritis International Society (ASAS) aimed to develop a set of quality standards (QS) to help improve the quality of healthcare provided to adult patients affected by axial spondyloarthritis (axSpA) worldwide. METHODS: An ASAS task force developed a set of QS using a stepwise approach. First, key areas for quality improvement were identified, discussed, rated and agreed on. Thereafter, areas were prioritised and statements for the most important key areas were phrased on consensus. Appropriate quality measures were defined to allow quantification of the QS at the community level. RESULTS: The ASAS task force, consisting of 20 rheumatologists, two physiotherapists and two patients, selected and proposed 34 potential key areas for quality improvement which were then commented by 140 ASAS members and patients. Within that process three new key areas came up, which led to a re-evaluation of all 37 key areas by 120 ASAS members and patients. Five key areas were identified as most important to determine quality of care: referral including rapid access, rheumatology assessment, treatment, education/self-management and comorbidities. Finally, nine QS were agreed on and endorsed by the whole ASAS membership. CONCLUSIONS: ASAS successfully developed the first set of QS to help improving healthcare for adult patients with axSpA. Even though it may currently not be realistic to achieve the QS in all healthcare systems, they provide high-quality of care framework for patients with axSpA that should be aimed for.


Asunto(s)
Atención a la Salud/normas , Reumatología/normas , Espondiloartritis , Adulto , Comités Consultivos , Consenso , Femenino , Humanos , Masculino , Mejoramiento de la Calidad , Sociedades Médicas
3.
Clin Oral Investig ; 23(2): 763-770, 2019 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-29779182

RESUMEN

OBJECTIVES: Implant-supported overdentures are an established dental treatment mode. The aim of this prospective study was and interindividual comparison of patient satisfaction with restorations retained by a prefabricated and thus inexpensive attachment system (Locator®) or with a technologically complex and thus expensive attachment system (ceramic/electroplated double crowns) with similar retentive performance. MATERIALS AND METHODS: Twelve patients received a Locator and a double-crown prosthesis in a crossover study for test periods of 3 months each. The main target parameter was the patient's final decision in favor of one of the two prosthesis types. RESULTS: After completing both test phases, seven patients opted for the Locator prosthesis and five patients opted for the double-crown prosthesis. CONCLUSION: Given the predominant lack of statistically significant differences, the two types of prostheses can be described as equivalent. A recommendation in favor of the Locator prosthesis can be motivated by its lower cost. CLINICAL RELEVANCE: The results of the study show that the more cost-effective variant was comparable to the more expensive double-crown prosthesis under the conditions prevailing in the study. Depending on the indication, this may influence the decision-making process in daily clinical practice and support the clinician's patient information and consultation efforts.


Asunto(s)
Coronas , Prótesis Dental de Soporte Implantado , Ajuste de Precisión de Prótesis , Prótesis de Recubrimiento , Prótesis Mandibular , Anciano , Cerámica , Estudios Cruzados , Diseño de Dentadura , Femenino , Humanos , Masculino , Satisfacción del Paciente , Estudios Prospectivos
4.
J Prosthet Dent ; 122(2): 123-128, 2019 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-30853140

RESUMEN

STATEMENT OF PROBLEM: The demand for occlusal devices to treat oral parafunction is rising. Conventionally, these occlusal devices are produced in the dental laboratory, which requires impressions and gypsum casts. Computer-aided design and computer-aided manufacturing (CAD-CAM) require fewer production steps and may offer greater comfort. Whether this is an improvement on conventional procedures is unclear. PURPOSE: The purpose of this crossover clinical study was to examine whether a digital workflow is feasible for fabricating occlusal devices to treat oral parafunction and to compare CAD-CAM-fabricated occlusal devices with conventionally produced ones to determine whether the digital method provides better results. MATERIAL AND METHODS: Thirty participants wore digitally fabricated occlusal devices for 3 months and then conventionally produced occlusal devices for another 3 months or vice versa. The main target parameter was the participant's preference for 1 of the device types. RESULTS: Both types had specific advantages and disadvantages, but the differences in participants' preference were not statistically significant. After completing the 2 testing periods, 16 participants preferred the laboratory-made device, whereas 12 participants preferred the digital occlusal device. Two participants dropped out during the study. CONCLUSIONS: Given the absence of statistically significant differences, the digitally fabricated device can be considered a suitable alternative to laboratory-made devices. Laboratory-made occlusal devices are now the gold standard. However, given the savings in terms of cost and treatment time, they may be replaced, particularly if the production process can be improved.


Asunto(s)
Diseño Asistido por Computadora , Coronas , Diseño de Prótesis Dental , Humanos , Laboratorios Odontológicos , Flujo de Trabajo
5.
BMC Oral Health ; 18(1): 182, 2018 11 01.
Artículo en Inglés | MEDLINE | ID: mdl-30382830

RESUMEN

BACKGROUND: Phobic patients avoid dental treatment impairing their oral health and making it challenging to offer them prosthetic rehabilitation. This study evaluated patients' experience of implant-supported prosthetic treatment after implantation performed under general anaesthesia due to dental phobia and severe pharyngeal reflexes (SPR). The effect of gender, age and location of implantation on patient satisfaction was tested. METHODS: Two hundred five patients underwent implantation under general anesthesia both in maxilla and mandible, respectively. After a trans-gingival healing period of 6-8 weeks, fixed implant bridges were inserted. Patients completed oral health impact profile questionnaire (OHIP-14). An additional set of six special questions was also developed and considered. Analysis of the OHIP-14 total score was made using logistics regression. Wald chi-square test was used to analyse the effect of age, gender and location of implantation. Effect sizes were estimated as odds-ratios and associated 95% Wald confidence intervals. RESULTS: Eighty two of 205 patients were included after prosthetic treatment. After start, 38 patients were excluded (4 died and 34 couldn't be reached). OHIP-14-analyses were made by 43 patients (30-90 years). 67% of patients were totally satisfied with the whole implant rehabilitation (scoring 0). Mean of total score was 2.5. Only age affected significantly (p = 0.014) patients satisfaction. The obtained data indicate that younger patients (30-64 years) especially women are less satisfied (4.95) than older patients (0.3) for age group (65-90 years).Special questions' data showed that 94.5% were satisfied with their treatment. 77.3% continued regular check-up after treatment and 96.9% would undergo the same treatment again. 95.5% would recommend implants to a friend of colleague. CONCLUSION: Gender and location of implantation have no significant influence on patient satisfaction. Younger patients especially women are less satisfied than older patients. Phobic patients are totally satisfied with implant rehabilitation under general anaesthesia which means that this treatment can be considered as a treatment of choice giving these patients the same opportunity like others to improve their oral health and well-being.


Asunto(s)
Anestesia General , Ansiedad al Tratamiento Odontológico , Implantación Dental Endoósea/métodos , Implantes Dentales , Prótesis Dental de Soporte Implantado , Satisfacción del Paciente , Adulto , Anciano , Anciano de 80 o más Años , Estética Dental , Femenino , Humanos , Masculino , Persona de Mediana Edad , Encuestas y Cuestionarios , Resultado del Tratamiento
6.
Clin Oral Investig ; 21(9): 2863-2871, 2017 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-28265772

RESUMEN

OBJECTIVES: Tooth colour determination is an essential component in the preservative and prosthetic workflow during production of tooth-coloured restorations. The aim of the study was to compare the clinical suitability of conventional, visual tooth colour determination and digital methods. MATERIALS AND METHODS: Tooth colour of vital, natural central incisors among a total of 107 subjects was determined visually by a dentist (VD) and dental technician (VDT) using VITA Toothguide 3D-MASTER®, digitally by the spectrophotometer VITA Easyshade Advance 4.0 (reference instrument) and Trios®Color intra-oral scanner (test subject). Reliability was examined by repeating the digital measurements of 20 teeth three times. The analysis was based on the recorded 3D-MASTER values and L*a*b/L*C*h parameters. RESULTS: The measuring accuracy was 43.9% with the Trios®Color scanner, 35.5% for VD and 34.6% for VDT. In 25.5% of cases, the scanner's results corresponded with VD and in 33.6% with VDT. The visual methods corresponded with 45.8%. All mean values of the recorded colour differences fell within the clinically acceptable range of ΔE ≤ 6.8. The intra-oral scanner attained repeatability of 78.3% and the VITA Easyshade system of 76.6%. CONCLUSIONS: The Trios®Color intra-oral scanner appears to be a good alternative to the current standard of visual tooth colour determination. The new module attains better results than the visual method and is comparable to the reference instrument. CLINICAL RELEVANCE: Dentistry becomes increasingly digitalized and tooth colour determination devices have generally to be improved. Therefore, the investigation of a new digital device is important for future developments.


Asunto(s)
Color , Colorimetría/instrumentación , Incisivo/anatomía & histología , Coloración de Prótesis , Adulto , Percepción de Color , Femenino , Humanos , Masculino , Persona de Mediana Edad , Reproducibilidad de los Resultados
7.
Ann Rheum Dis ; 75(6): 1034-42, 2016 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-26865599

RESUMEN

OBJECTIVE: To establish the predictive validity of the Assessment of SpondyloArthritis international Society (ASAS) spondyloarthritis (SpA) classification criteria. METHODS: 22 centres (N=909 patients) from the initial 29 ASAS centres (N=975) participated in the ASAS-cohort follow-up study. Patients had either chronic (>3 months) back pain of unknown origin and age of onset below 45 years (N=658) or peripheral arthritis and/or enthesitis and/or dactylitis (N=251). At follow-up, information was obtained at a clinic visit or by telephone. The positive predictive value (PPV) of the baseline classification by the ASAS criteria was calculated using rheumatologist's diagnosis at follow-up as external standard. RESULTS: In total, 564 patients were assessed at follow-up (345 visits; 219 telephone) with a mean follow-up of 4.4 years (range: 1.9; 6.8) and 70.2% received a SpA diagnosis by the rheumatologist. 335 patients fulfilled the axial SpA (axSpA) or peripheral SpA (pSpA) criteria at baseline and of these, 309 were diagnosed SpA after follow-up (PPV SpA criteria: 92.2%). The PPV of the axSpA and pSpA criteria was 93.3% and 89.5%, respectively. The PPV for the 'clinical arm only' was 88.0% and for the 'clinical arm'±'imaging arm' 96.0%, for the 'imaging arm only' 86.2% and for the 'imaging arm'+/-'clinical arm' 94.7%. A series of sensitivity analyses yielded similar results (range: 85.1-98.2%). CONCLUSIONS: The PPV of the axSpA and pSpA criteria to forecast an expert's diagnosis of 'SpA' after more than 4 years is excellent. The 'imaging arm' and 'clinical arm' of the axSpA criteria have similar predictive validity and are truly complementary.


Asunto(s)
Dolor de Espalda/diagnóstico , Espondiloartritis/diagnóstico , Adulto , Edad de Inicio , Vértebra Cervical Axis , Dolor de Espalda/etiología , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Estudios Prospectivos , Reproducibilidad de los Resultados , Espondiloartritis/complicaciones
8.
Clin Exp Rheumatol ; 34(2): 184-90, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27049733

RESUMEN

OBJECTIVES: Knowledge on the long-term effects of anti-TNF therapy in patients with ankylosing spondylitis (AS) is still limited. Our objective was to study the long-term efficacy and safety of anti-TNF therapy in AS. METHODS: After having completed the first part of the EASIC trial a total of 71 patients were enrolled into this 96-week extension study. Patients were treated with the same dosages and dosing intervals of infliximab as in the EASIC core study. Efficacy was assessed by using standardised assessment tools such as BASDAI, BASFI, BASMI, patient global assessment, CRP levels and the proportion of patients without any sign of enthesitis or arthritis. Long-term safety was assessed by documenting adverse events (AE), serious adverse events (SAE) and reasons for dropping out. RESULTS: Of the 71 patients included, 64 (90.1%) completed the trial , and 7 discontinued: one was lost to follow-up, 3 withdrew informed consent and in 3 patients therapy was stopped for different reasons: secondary loss of response, recurrent infections and basal cell carcinoma of the skin. The completers showed rather stable low scores of BASDAI (mean 2.4, median 2.52), BASFI (mean 3.1, median 2.76) and BASMI (mean 3.2, median 3) as well as patients global assessment and CRP. The vast majority of patients did not have enthesitis or arthritis. A total of 476 AE were observed, 13 of which were SAE. The majority of these were infections and most of them affected the respiratory tract. Two malignancies occurred: one basal cell carcinoma and one malignant melanoma. These were the only SAE judged to be possibly related to the study drug. CONCLUSIONS: Anti-TNF treatment with infliximab is efficacious over long periods of time in patients with AS. The observation of two skin related malignancies, including one melanoma, during the whole study period of 7 years is in line with reports from previous large AS data sets.


Asunto(s)
Antirreumáticos/uso terapéutico , Infliximab/uso terapéutico , Espondilitis Anquilosante/tratamiento farmacológico , Factor de Necrosis Tumoral alfa/antagonistas & inhibidores , Adulto , Antirreumáticos/efectos adversos , Proteína C-Reactiva/análisis , Estudios de Cohortes , Femenino , Humanos , Infliximab/efectos adversos , Masculino , Persona de Mediana Edad , Espondilitis Anquilosante/sangre
9.
J Prosthet Dent ; 114(4): 469-73, 2015 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-26187099

RESUMEN

A digital process is presented for an implant-supported single-tooth and a 3-unit fixed dental prosthesis (FDP) with customized abutments and monolithic prosthetic zirconia restorations. The digital impression on the implant level was made with a TRIOS intraoral scanner (3Shape). This process included the fabrication of an implant cast with the fused deposition modeling technique and a 3-dimensional printing process with integrated implant analogs. The process enabled the FDPs to be designed with CAD/CAM on the cast before patient contact. Designing a printed implant cast expands the use of the digital workflow in the dental field.


Asunto(s)
Diseño Asistido por Computadora , Coronas , Materiales Dentales/química , Prótesis Dental de Soporte Implantado , Impresión Tridimensional , Anciano , Cementación , Técnica de Impresión Dental , Humanos , Masculino
10.
J Arthroplasty ; 29(10): 2049-52, 2014 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-24997654

RESUMEN

Eight retrieved metal-on-metal total hip replacements displayed corrosion damage along the cobalt-chromium alloy liner taper junction with the Ti alloy acetabular shell. Scanning electron microscopy indicated the primary mechanism of corrosion to be grain boundary and associated crevice corrosion, which was likely accelerated through mechanical micromotion and galvanic corrosion resulting from dissimilar alloys. Coordinate measurements revealed up to 4.3mm(3) of the cobalt-chromium alloy taper surface was removed due to corrosion, which is comparable to previous reports of corrosion damage on head-neck tapers. The acetabular liner-shell taper appears to be an additional source of metal corrosion products in modular total hip replacements. Patients with these prostheses should be closely monitored for signs of adverse reaction towards corrosion by-products.


Asunto(s)
Acetábulo/cirugía , Artroplastia de Reemplazo de Cadera/efectos adversos , Prótesis de Cadera/efectos adversos , Falla de Prótesis , Adulto , Anciano , Materiales Biocompatibles , Aleaciones de Cromo , Corrosión , Remoción de Dispositivos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Diseño de Prótesis , Titanio
11.
J Arthroplasty ; 28(6): 1036-40, 2013 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-23528551

RESUMEN

The primary goal of this study was to determine if head size affects corrosion and fretting behaviour at the head-neck taper interface of modular hip prostheses. Seventy-four implants were retrieved that featured either a 28 mm or a 36 mm head with a metal-on-polyethylene articulation. The bore of the heads and the neck of the stems were divided into eight regions each and graded by three observers for corrosion and fretting damage separately using modified criteria as reported in the literature. The 36 mm head size featured a significant difference in the corrosion head scores (p=0.022) in comparison to the 28 mm heads. This may be attributed to a greater torque acting along the taper interface due to activities of daily living.


Asunto(s)
Prótesis de Cadera , Diseño de Prótesis/efectos adversos , Falla de Prótesis/etiología , Anciano , Corrosión , Femenino , Humanos , Masculino
12.
J Arthroplasty ; 28(1): 197.e17-21, 2013 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-22770854

RESUMEN

A 34-year-old female patient received a cobalt-chromium (CoCr) alloy femoral head on cross-linked polyethylene total hip replacement for the revision of her fractured ceramic-on-ceramic total hip replacement. The CoCr alloy femoral head became severely worn due to third-body abrasive wear by ceramic particles that could not be removed by synovectomy or irrigation at revision surgery. Ceramic particles were found embedded in the cross-linked polyethylene liner. The CoCr alloy femoral head exhibited a total mass loss of 14.2 g and the generated wear particles triggered metallosis in the patient. The present case study suggests not revising a fractured ceramic-on-ceramic total hip replacement with a CoCr alloy femoral head and a cross-linked polyethylene liner to avoid metallosis due to third-body abrasive wear.


Asunto(s)
Artroplastia de Reemplazo de Cadera , Aleaciones de Cromo/efectos adversos , Prótesis de Cadera/efectos adversos , Polietilenos/efectos adversos , Falla de Prótesis , Adulto , Cerámica/efectos adversos , Femenino , Humanos , Reoperación , Estrés Mecánico
13.
RMD Open ; 9(4)2023 Dec 19.
Artículo en Inglés | MEDLINE | ID: mdl-38114198

RESUMEN

BACKGROUND: The influence of sex on treatment outcomes during interleukin-12/23 therapy in patients with psoriatic arthritis (PsA) has not been explored. OBJECTIVE: To conduct exploratory post hoc analyses of sex-stratified data from the MUST trial, an investigator-initiated, multicentre, phase 3b study in which patients with active PsA initiating treatment with open-label ustekinumab were randomised to treatment with placebo or methotrexate (MTX). METHODS: We evaluated baseline characteristics, key treatment outcomes and adverse events stratified by sex, with a focus on outcomes that did not include erythrocyte sedimentation rate (ESR) as a component due to the known elevation of ESR in females. RESULTS: A total of 166 patients were treated with ustekinumab+MTX (37 female, 50 male) or ustekinumab+placebo (32 female, 47 male). At baseline, females had a significantly longer time since PsA diagnosis and greater impairment in physical function, but similar joint counts. At week 24, both females and males showed marked improvements to ustekinumab with or without MTX. Females generally had numerically reduced treatment responses compared with males, although differences did not achieve statistical significance. MTX did not show an overall effect on treatment outcomes, but was associated with faster enthesitis responses in males only. Adverse events were generally comparable, but females in the ustekinumab+MTX group had higher levels of gastrointestinal disorders. CONCLUSION: Females and males with PsA had differences in baseline characteristics, treatment responses and adverse events during therapy. A better understanding of sex-based differences in PsA may help optimise treatment.


Asunto(s)
Antirreumáticos , Artritis Psoriásica , Femenino , Humanos , Masculino , Antirreumáticos/efectos adversos , Artritis Psoriásica/diagnóstico , Artritis Psoriásica/tratamiento farmacológico , Ensayos Clínicos Fase III como Asunto , Interleucina-12 , Metotrexato/efectos adversos , Estudios Multicéntricos como Asunto , Ensayos Clínicos Controlados Aleatorios como Asunto , Ustekinumab/efectos adversos , Resultado del Tratamiento
14.
Proc Inst Mech Eng H ; 226(3): 235-45, 2012 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-22558838

RESUMEN

The micromotion at the interface between the polyethylene tibial insert and metal tibial tray [corrected] in modular total knee replacements [corrected] has been shown to contribute to wear particle-induced osteolysis and may [corrected] cause implant failure. Therefore, studying the design parameters that are involved in the backside wear process is an important task that may lead to improvement in new total knee replacements. In the present study, a finite element model was developed to predict the backside micromotion along the entire modular interface. Both the linear elastic constitutive model and non-linear J2-plasticity constitutive model were considered in the finite element model for polyethylene and were corroborated against published results obtained from displacement controlled knee simulator wear tests. The finite element simulation with the non-linear J2-plasticity constitutive model was able to predict backside micromotion [corrected] more accurately than the simulation with the linear elastic constitutive model. [corrected] The developed finite element model (including the non-linear J2-plasticity constitutive model) was then applied to assess the effects of the tibial tray locking mechanism design (dovetails versus fullperipheral [corrected] design) and different levels of interference fit on insert micromotion. The developed finite element model, implementing the non-linear J2-plasticity constitutive model, was shown to successfully predict clinical amounts of backside micromotion and could be used for the design and development of total knee replacements for the reduction of backside micromotion and polyethylene [corrected] wear.


Asunto(s)
Inestabilidad de la Articulación/fisiopatología , Inestabilidad de la Articulación/cirugía , Articulación de la Rodilla/fisiopatología , Articulación de la Rodilla/cirugía , Prótesis de la Rodilla , Modelos Biológicos , Rango del Movimiento Articular , Simulación por Computador , Humanos , Movimiento (Física) , Resultado del Tratamiento
15.
Proc Inst Mech Eng H ; 226(6): 427-40, 2012 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-22783759

RESUMEN

Calf serum lubricants consisting of various polypeptide constituent fractions are routinely used in knee wear simulators as part of the standardized test protocol. Three calf sera (bovine, new-born and alpha) were diluted as per the recommendation of ISO 14243-3 and used in displacement-controlled knee wear simulators to investigate their effects on polyethylene wear. Biochemical analyses included measuring total polypeptide degradation, electrophoretic profiles and low-molecular weight polypeptide concentrations to elucidate their involvement in the wear process. The effects of the various calf sera constituent fractions on microbial growth were also explored. The polyethylene wear rates and the results from the biochemical analyses for the three calf serum lubricants were all found to be statistically significantly different from each other. The lubricant derived from the alpha-calf serum was closest in constituent fractions to human synovial fluid. It also showed the lowest polyethylene wear rate (14.38 +/- 0.85 mm3/million cycles) and the lowest amount of polypeptide degradation (7.77 +/- 3.87%). Furthermore, the alpha-calf serum lubricant was associated with the least amount of change in the electrophoretic profile, the least change in low-molecular weight polypeptide concentration, and the lowest microbial growth in the presence of sodium azide (a microbial inhibitor conventionally used in implant wear testing). Replacing sodium azide with a broad spectrum antibiotic-antimycotic eradicated the microbial growth. Some speculation was entertained regarding the effect of alpha-calf serum on colloid-mediated boundary lubrication. Based on the results, it was recommended that ISO 14243-3 be modified to include guidelines on calf serum constituent fractions that would favour using alpha-calf serum in order to improve the fidelity of the simulation in knee implant wear testing.


Asunto(s)
Prótesis de la Rodilla/microbiología , Lubricantes/química , Ensayo de Materiales/métodos , Polietilenos/química , Suero/química , Análisis de Varianza , Animales , Bovinos , Guías como Asunto , Humanos , Rodilla/fisiopatología , Prótesis de la Rodilla/normas , Lubricantes/análisis , Lubricantes/normas , Ensayo de Materiales/normas , Polietilenos/análisis , Polietilenos/normas , Proteolisis , Líquido Sinovial/química
16.
J Long Term Eff Med Implants ; 22(1): 21-31, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-23016787

RESUMEN

In the present study, surface and subsurface damage due to wear and creep in retrieved tibial inserts from the Genesis II total knee replacement (Smith & Nephew, Memphis, TN) are quantified. The utility of a number of recently validated micro-computed tomography (micro-CT) techniques for use in retrieval studies are also demonstrated. Sixteen inserts retrieved from patients after an implantation time from 0.5 to 86 months were examined. The inserts were scanned using micro-CT, and the three-dimensional surface deviations (corresponding to wear and creep) between the retrieved inserts and a reference geometry were determined. The subsurface of the inserts was also examined. Deviations within damage features were measured, and a surface deviation rate (mm/ year) was calculated from the length of implantation. No subsurface fatigue damage was found. The mean deviation within the most damaged regions of the articular surface was 0.115 ± 0.064 mm medially and 0.099 ± 0.061 mm laterally (p = 0.20). The mean articular deviation rate for inserts in vivo for more than 1 year was 0.049 mm/year and was reduced to 0.026 mm/year in inserts implanted for more than 4 years. Wear and creep of the Genesis II PE insert was comparable to reported values in other total knee replacements.


Asunto(s)
Artroplastia de Reemplazo de Rodilla/instrumentación , Análisis de Falla de Equipo/métodos , Prótesis de la Rodilla , Falla de Prótesis , Remoción de Dispositivos , Femenino , Humanos , Imagenología Tridimensional , Masculino , Polietileno , Diseño de Prótesis , Microtomografía por Rayos X
17.
Clin Orthop Relat Res ; 469(1): 107-12, 2011 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-20676810

RESUMEN

BACKGROUND: Wear of polyethylene tibial inserts can decrease the longevity of total knee arthroplasty. Wear is currently assessed using laboratory methods that may not permit backside wear measurements or do not quantify surface deviation. QUESTIONS/PURPOSES: We developed and validated a technique to quantify polyethylene wear in tibial inserts using microcomputed tomography (micro-CT), a nondestructive high-resolution imaging technique that provides detailed images of surface geometry in addition to volumetric measurements. METHODS: Six unworn and six wear-simulated polyethylene tibial inserts were evaluated. Each insert was scanned three times using micro-CT at a resolution of 50 µm. The insert surface was reconstructed for each scan and the insert volume was calculated. Gravimetric analysis was performed for all inserts, and the micro-CT and gravimetric volumes were compared to determine accuracy. We created three-dimensional surface deviation maps. RESULTS: Micro-CT generated high-quality three-dimensional renderings of the insert surface geometry. Between-scan precision was 0.07%; we observed no difference between micro-CT and gravimetric volume measurements. CONCLUSIONS: Micro-CT can provide precise and accurate volumetric measurements in addition to quantifiable three-dimensional surface deviation maps for the entire insert surface. The technique has the potential to evaluate wear in wear simulator trials and retrieval studies. CLINICAL RELEVANCE: This micro-CT technique combines the benefits of volumetric and surface scanning methods to quantify wear across all surfaces of polyethylene components with a single tool. When applied in wear simulator and retrieval studies, these measurements can be used to evaluate and predict the wear properties of the components.


Asunto(s)
Artroplastia de Reemplazo de Rodilla/instrumentación , Prótesis de la Rodilla , Polietileno , Falla de Prótesis , Microtomografía por Rayos X , Artroplastia de Reemplazo de Rodilla/efectos adversos , Estudios de Factibilidad , Imagenología Tridimensional , Ensayo de Materiales , Proyectos Piloto , Diseño de Prótesis , Reproducibilidad de los Resultados , Estrés Mecánico , Propiedades de Superficie
18.
J Arthroplasty ; 26(8): 1460-7, 2011 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-21570806

RESUMEN

Twenty-two retrieved femoral knee components were identified with posterior condyle surface damage on average at 99° flexion (range, 43°-135° flexion). Titanium alloy material transfer and abrasive surface damage were evident on cobalt-chromium alloy femoral components that were in contact with titanium alloy tibial trays. Surface damage on the retrieved Oxinium femoral components (Smith and Nephew, Inc, Memphis, Tenn) that were in contact with titanium alloy tibial trays showed gouging, associated with the removal and cracking of the oxide and exposure of the zirconium-niobium alloy substrate. Cobalt-chromium alloy femoral components that were in contact with cobalt-chromium alloy tibial trays showed abrasive wear. Contact between the femoral component and tibial tray should be avoided to prevent surface damage to the femoral condyles, which could potentially accelerate polyethylene wear in vivo.


Asunto(s)
Artroplastia de Reemplazo de Rodilla/instrumentación , Artroplastia de Reemplazo de Rodilla/métodos , Fémur , Articulación de la Rodilla/cirugía , Prótesis de la Rodilla , Osteólisis/cirugía , Diseño de Prótesis , Aleaciones de Cromo/efectos adversos , Femenino , Humanos , Articulación de la Rodilla/fisiopatología , Masculino , Microscopía Electrónica de Rastreo , Niobio/efectos adversos , Osteoartritis de la Rodilla/cirugía , Osteólisis/etiología , Falla de Prótesis , Rango del Movimiento Articular/fisiología , Reoperación , Estudios Retrospectivos , Propiedades de Superficie , Titanio/efectos adversos , Circonio/efectos adversos
19.
Clin Implant Dent Relat Res ; 21(2): 317-323, 2019 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-30784167

RESUMEN

BACKGROUND: Telescopic prostheses are an evidence-based treatment modality, and conical zirconia crowns and electro-formed gold copings have been used for dentures supported by teeth and/or implants. PURPOSE: We aimed to evaluate the survival rates of zirconia-based tooth/implant restorations. MATERIALS AND METHODS: A total of 126 telescopic overdentures, all retained by conical zirconia crowns and electro-formed gold copings, were retrospectively evaluated and failures analyzed for abutment configurations. Survival rates and modifying factors were evaluated by Kaplan-Meier analysis, log-rank testing, and Cox regression analysis. RESULTS: We evaluated observation periods of up to 11.5 years (mean: 45.25 ± 25.11 months). Five-year prosthesis survival was 96.9 ± 2.2% (95% CI: 92.6-100). Six dentures had been lost, and these failures were significantly associated with specific abutment configurations. CONCLUSIONS: Within the limitations of this retrospective study, the concept of conical zirconia telescoping into electro-formed gold provides a viable alternative to other telescopic designs used for removable dental prostheses. The concept is well suited especially for tooth/implant-supported prosthetic rehabilitation.


Asunto(s)
Diseño de Prótesis Dental , Dentadura Parcial Removible , Circonio , Coronas , Pilares Dentales , Prótesis Dental de Soporte Implantado , Fracaso de la Restauración Dental , Oro , Estudios Retrospectivos
20.
Int J Oral Maxillofac Implants ; 33(2): 328-334, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29534120

RESUMEN

PURPOSE: The aim of this in vitro study was to evaluate the accuracy of template-guided implantation planned with implant-planning software (Implant Studio), comparing computer-aided design/computer-assisted manufacture (CAD/CAM)-based measurements with measurements via cone beam computed tomography (CBCT). MATERIALS AND METHODS: Thirty template-guided implantations were planned and performed on acrylic-resin models. The implant positions were detected with an intraoral scanner, evaluated with CAD quality-control software, and compared with the planned positions in the test group. Preliminary deviations were measured via CBCT in the control group of the first 10 samples and compared with the first 10 samples of the test group. RESULTS: When directly compared, measurements obtained using CBCT (control group) showed a trend toward greater deviations. In the CAD/CAM-based evaluation of the 30 samples, the mean ± SD deviation of the insertion axis from the planned implant axis was 2.011 ± 0.855 degrees. The mean deviations of the implant shoulders in the horizontal direction and at the implant apices were 0.725 ± 0.142 mm and 0.990 ± 0.244 mm, respectively. In the vertical direction, the mean deviation was 0.541 ± 0.129 mm. CONCLUSION: CAD/CAM-based measurements are more accurate than CBCT measurements. Therefore, this radiation-free measurement method is a viable diagnostic alternative. Implant planning with planning software and subsequent placement using surgical templates appears to be a reliable and precise therapeutic option in vitro. However, these findings will still have to be supported by in vivo studies.


Asunto(s)
Diseño Asistido por Computadora , Implantación Dental Endoósea/métodos , Cirugía Asistida por Computador/métodos , Tomografía Computarizada de Haz Cónico , Humanos , Imagenología Tridimensional/métodos , Planificación de Atención al Paciente , Reproducibilidad de los Resultados , Programas Informáticos
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