Implantes de titanio trabecular en cirugía de revisión acetabular compleja / Trabecular titanium implants in complex acetabular revision surgery

Introducción: La cirugía de revisión acetabular supone un reto quirúrgico sobre todo cuando aparecen los defectos óseos complejos, pues dificultan la fijación primaria y osteointegración de los implantes, lo que condiciona la aparición de complicaciones. Los cotilos de titanio trabecular intentan solventar estos problemas. Objetivos: Valorar los resultados clínico-radiológicos, la supervivencia de los implantes y aparición de complicaciones a medio plazo en cirugía de revisión acetabular en una serie de 37 recambios acetabulares con defectos óseos tipo IIIA y IIIB de Paprosky en los que se utilizó un implante de revisión tipo Cup-Cage de titanio trabecular. Material y método: Realizamos un estudio observacional, descriptivo y retrospectivo de 37 casos con defectos acetabulares complejos (20 tipo IIIA y 17 tipo IIIB, cinco de ellos con discontinuidad pélvica) en los que se realizó recambio del componente acetabular por implantes de titanio trabecular entre los años 2011 y 2019. Analizamos resultados clínicos (dolor y funcionalidad) y parámetros radiológicos (restauración del centro de rotación de la cadera y la movilización de los implantes), así como la aparición de complicaciones. Resultados: El seguimiento medio fue de 61 meses. Obtuvimos una mejoría en la mediana de 8 puntos en la escala de funcionalidad de Merlé D’Aubigné-Postel y de 6 puntos en la escala EVA de dolor percibido por el paciente. Registramos dos casos de aflojamiento acetabular, un caso de inestabilidad y tres infecciones de herida quirúrgica sin afectar al implante. Conclusiones: La utilización de implantes tipo Cup-Cage de titanio trabecular podría constituir una opción válida en cirugía de revisión acetabular con defectos acetabulares complejos, presentando buenos resultados clínico-radiológicos y en cuanto a complicaciones y supervivencia de los implantes, debido a su buena fijación primaria y osteointegración.(AU)

Introduction: Acetabular revision surgery is a surgical challenge, especially when complex bone defects appear. This makes primary fixation and osseointegration of the implants difficult, which conditions the appearance of complications. Trabecular titanium implants attempt to solve these problems. Objectives: To evaluate our clinical-radiological results, the survival of the implants and the appearance of mid-term complications in acetabular revision surgery in a series of 37 acetabular replacements with Paprosky type IIIA and IIIB bone defects in which a trabecular titanium Cup-Cage revision implant was used. Material and method: We conducted an observational, descriptive and retrospective study of 37 cases with complex acetabular defects (20 type IIIA and 17 type IIIB, five of them with pelvic discontinuity) in which the acetabular component was replaced by trabecular titanium cups between 2011 and 2019. We analyzed clinical results (pain and functionality) and radiological parameters (restoration of the hip rotation centre and the mobilization of the implants), as well as the appearance of complications. Results: The mean follow-up was 61 months. We obtained a median improvement of 8 points on the Merlé D’Aubigné-Postel functionality scale and 6 points on the VAS scale of pain perceived by the patient. We recorded two cases of acetabular loosening, one case of dislocation and three surgical wound infections without affecting the implant. Conclusions: The use of trabecular titanium Cup-Cage implants could be a valid option in acetabular revision surgery with complex acetabular defects, presenting good clinical and radiological results and in terms of complications and survival of the implants, mainly due to their good primary fixation and subsequent osseointegration.(AU)

[Translated article] Trabecular titanium implants in complex acetabular revision surgery / Implantes de titanio trabecular en cirugía de revisión acetabular compleja

Introducción: La cirugía de revisión acetabular supone un reto quirúrgico sobre todo cuando aparecen los defectos óseos complejos, pues dificultan la fijación primaria y osteointegración de los implantes, lo que condiciona la aparición de complicaciones. Los cotilos de titanio trabecular intentan solventar estos problemas. Objetivos: Valorar los resultados clínico-radiológicos, la supervivencia de los implantes y aparición de complicaciones a medio plazo en cirugía de revisión acetabular en una serie de 37 recambios acetabulares con defectos óseos tipo IIIA y IIIB de Paprosky en los que se utilizó un implante de revisión tipo Cup-Cage de titanio trabecular. Material y método: Realizamos un estudio observacional, descriptivo y retrospectivo de 37 casos con defectos acetabulares complejos (20 tipo IIIA y 17 tipo IIIB, cinco de ellos con discontinuidad pélvica) en los que se realizó recambio del componente acetabular por implantes de titanio trabecular entre los años 2011 y 2019. Analizamos resultados clínicos (dolor y funcionalidad) y parámetros radiológicos (restauración del centro de rotación de la cadera y la movilización de los implantes), así como la aparición de complicaciones. Resultados: El seguimiento medio fue de 61 meses. Obtuvimos una mejoría en la mediana de 8 puntos en la escala de funcionalidad de Merlé D’Aubigné-Postel y de 6 puntos en la escala EVA de dolor percibido por el paciente. Registramos dos casos de aflojamiento acetabular, un caso de inestabilidad y tres infecciones de herida quirúrgica sin afectar al implante. Conclusiones: La utilización de implantes tipo Cup-Cage de titanio trabecular podría constituir una opción válida en cirugía de revisión acetabular con defectos acetabulares complejos, presentando buenos resultados clínico-radiológicos y en cuanto a complicaciones y supervivencia de los implantes, debido a su buena fijación primaria y osteointegración.(AU)

Introduction: Acetabular revision surgery is a surgical challenge, especially when complex bone defects appear. This makes primary fixation and osseointegration of the implants difficult, which conditions the appearance of complications. Trabecular titanium implants attempt to solve these problems. Objectives: To evaluate our clinical-radiological results, the survival of the implants and the appearance of mid-term complications in acetabular revision surgery in a series of 37 acetabular replacements with Paprosky type IIIA and IIIB bone defects in which a trabecular titanium Cup-Cage revision implant was used. Material and method: We conducted an observational, descriptive and retrospective study of 37 cases with complex acetabular defects (20 type IIIA and 17 type IIIB, five of them with pelvic discontinuity) in which the acetabular component was replaced by trabecular titanium cups between 2011 and 2019. We analyzed clinical results (pain and functionality) and radiological parameters (restoration of the hip rotation centre and the mobilization of the implants), as well as the appearance of complications. Results: The mean follow-up was 61 months. We obtained a median improvement of 8 points on the Merlé D’Aubigné-Postel functionality scale and 6 points on the VAS scale of pain perceived by the patient. We recorded two cases of acetabular loosening, one case of dislocation and three surgical wound infections without affecting the implant. Conclusions: The use of trabecular titanium Cup-Cage implants could be a valid option in acetabular revision surgery with complex acetabular defects, presenting good clinical and radiological results and in terms of complications and survival of the implants, mainly due to their good primary fixation and subsequent osseointegration.(AU)

Estudio comparativo de la cobertura neointimal entre los stents con recubrimiento de titanio-óxido nítrico y los liberadores de everolimus en el sindrome coronario agudo / Comparative study of neointimal coverage between titanium-nitric oxide-coated and everolimus-eluting stents in acute coronary syndromes

Introducción y objetivos Evaluar mediante tomografía de coherencia óptica (OCT) el proceso de cicatrización neointimal tras el implante de stents de cromo cobalto con recubrimiento de titanio-óxido nítrico (TiNO) y de stents de platino-cromo liberadores de everolimus (SLE) con polímero biodegradable en pacientes con síndrome coronario agudo. Métodos Los pacientes fueron aleatorizados (1:1) para recibir el stent TiNO o SLE. Se obtuvieron imágenes de OCT a los 30 días (cohorte A, n=52) y a los 6 meses (cohorte B, n=30) de seguimiento. El objetivo primario del estudio fue el porcentaje de struts no cubiertos por paciente. Resultados En la cohorte A, el porcentaje de struts no cubiertos fue menor con los stents TiNO que con los SLE (3,2% frente a 19,6%, p <0,001). El porcentaje de struts mal apuestos fue del 0,4% en el grupo TiNO y del 2,1% en el grupo SLE (p <0,001). En la cohorte B, el porcentaje de struts no cubiertos también fue menor con los stents TiNO (0,0% frente a 8,7% (p <0,001). El porcentaje de struts mal apuestos fue del 0% en el grupo de stent TiNO y del 0,3% en el grupo de SLE (p=0,008). A ninguno de los pacientes se les tuvo que repetir la revascularización durante los 6 meses de seguimiento. Conclusiones Tras una intervención percutánea por síndrome coronario agudo, el implante de un stent TiNO se asoció a un menor porcentaje de struts no cubiertos y mal apuestos por paciente, en comparación con el SLE, en un seguimiento temprano y a medio plazo (AU)

Introduction and objectives To evaluate by optical coherence tomography neointimal healing response after implantation of cobalt-chromium-based titanium-nitride-oxide-coated (TiNO) stents and platinum-chromium-based biodegradable-polymer-coated everolimus-eluting stents (EES) in patients with acute coronary syndrome. Methods Patients were randomized (1:1) to receive either a TiNO-stent or EES. Optical coherence tomography images were obtained at 30-day (cohort A, n = 52) and 6-month (cohort B, n = 30) follow-up. The primary endpoint was the percentage of uncovered struts per patient. Results In cohort A, the percentage of uncovered struts was lower with TiNO-stents vs EES (3.2% vs 19.6%, P <.001). The percentage of malapposed struts was 0.4% in the TiNO-group and 2.1% in the EES group (P <.001). In cohort B, the percentage of uncovered struts was also lower with TiNO-stents (0.0% vs 8.7% (P <.001). The percentage of malapposed struts was 0% in the TiNO-stent group and 0.3% in the EES group (P=.008). None of the patients had repeat revascularization during the 6 months of follow-up. Conclusions Following percutaneous intervention for acute coronary syndrome, TiNO stent implantation was associated with a lower percentage of uncovered and malapposed struts per patient, compared with EES, at early and mid-term follow-up (AU)

Thermal necrosis-aided dental implant removal: A rabbit model pilot study

Background: The significant advances in the materials and biological aspects of dental implants haven't completely eradicated the implant failures. The removal of osseointegrated but otherwise failed implants present several challenges including adjacent tissues damage and necessity of bone augmentation for reimplantation. Controlled thermal necrosis has emerged as an alternative technique to aid removal of osseointegrated dental implants with minimal to no defect to healthy bone or surrounding tissues. This study aimed to evaluate the thermal necrosis-aided implant removal method in a rabbit osseointegration model. Material and methods: A total of 8 male New Zealand rabbits were used in the study. Two dental implants were placed on each femur of the rabbits. Heating of the implants was performed after 7 weeks following the implantation. Heating was done by contacting the tip of an electrosurgey tool in monopolar mode at different power settings and contact durations (5W - 2 seconds, 5W - 10 seconds, and 10 W - 10 seconds). No heating was done on the control group. Implant stability right after implantation, before heat application and after heat application was determined using an Osstell™ Mentor Device. Following the removal of implants histological analyses were performed to determine the effects of heat application at cellular level. Results: ISQ values of the 10W-10s group was significantly lower compared to the other groups (p<0.001). No indication of progressive necrosis or irreversible damage was observed in any of the groups. However, the percent of empty-apoptotic lacunae were statistically higher in the 5W-10s and the 10W-10s groups compared the control and the 5W-2s groups. Conclusions: Within the conditions of this study, we conclude that heat application with an electrosurgery tool using monopolar mode at 10W power for 10 seconds is optimal for reversing osseointegration with no extensive or progressive damage to the bone. (AU)

Effects of a local single dose administration of growth hormone on the osseointegration of titanium implants

Background: The aim of the present study was to evaluate the effect of different concentrations of growth hormone (GH) on endosteal implant’s surface at the early stages of osseointegration. Material and Methods: Sixty tapered acid-etched titanium implants were divided into four groups: i) Collagen, used as a control group; and three experimental groups, where after collagen coating, GH was administered directly to the surface in varying concentrations: ii) 0.265 mg, iii) 0.53 mg, and iv) 1 mg. Implants were placed in an interpolated fashion in the anterior flange of C3, C4 or C5 of 15 sheep with minimum distance of 6 mm between implants. After 3-, 6- and 12-weeks of healing samples were harvested, histologically processed, qualitatively and quantitatively assessed for bone-to-implant contact (BIC) and bone area fraction occupancy (BAFO). Results: Statistical analysis as a function of time in vivo and coating resulted in no significant differences for BIC and BAFO at any evaluation time point. Histological evaluation demonstrated similar osseointegration features for all groups with woven bone formation at 3 weeks and progressive replacement of woven for lamellar bone in close contact with the implant surface and within the implant’s threads. Conclusions: A single local application of growth hormone to the surface of titanium implants did not yield improved implant osseointegration independent of healing time.(AU)

Combination therapy with TiO2 nanoparticles and cisplatin enhances chemotherapy response in murine melanoma models

Background Despite recent progressions in the treatment of melanoma, the response to conventional therapies and the long-term survival in melanoma patients still remain poor. Recently, the use of nanoparticles (NPs) has been highlighted for promoting the chemotherapeutic effects of cytotoxic drugs in melanoma. The aim of this study is to mechanistically evaluate the potential of titanium dioxide (TiO2) nanoparticles (NPs) for enhancing chemotherapy effects in in vitro and in vivo models of murine melanoma. Methods The F10 melanoma cells were exposed to different concentrations of TiO2 NPs and/or cisplatin, then cell growth, cell viability, and cell death were evaluated. In parallel, C57BL/6 syngeneic melanoma mice were treated by TiO2 NPs and/or cisplatin, and then drug responses, tumor size and mice’s organs were studied pathologically. Autophagy was examined by evaluating the formation of autophagosomes and gene expression levels of autophagy markers (ATG5 and ATG6) by fluorescent microscopy and qPCR, respectively. Results Nontoxic concentrations of TiO2 NPs (50 µg/ml) promote anti-proliferative and cytotoxic effects of cisplatin in F10 melanoma cells, which is mediated through the induction of autophagy and necrotic cell death. Whereas TiO2 NPs have no cytotoxic or metastatic effects in melanoma mice, its combination with cisplatin enhances drug responses (up to 50%), leading to higher inhibition of tumor growth compared with each monotherapy. Conclusion The combination of TiO2 NP with cisplatin enhances chemotherapy response in both in vitro and in vivo melanoma models. In addition, autophagy plays an essential role during sensitizing melanoma cells to chemotherapy (AU)

Alveoloplastias y utilización de material de osteosíntesis en la fisura labiopalatina / Alveoloplasty and the use of osteosynthesis material in the cleft lip palate

OBJETIVOS: Comparar los resultados de alveoloplastias secundarias realizadas en nuestro Hospital cuando utilizamos material de osteosíntesis y cuando el injerto óseo no precisa de dicho material, relacionándolos con factores como el sexo y la edad. MATERIAL Y MÉTODOS: Realizamos estudio retrospectivo de los años 2014-2019 en nuestro Hospital y seleccionamos los pacientes que cumplían los criterios de inclusión en nuestro estudio. Establecimos 2 grupos de edades: grupo A, edades entre 5-12 años (alveoloplastia secundaria mixta); grupo B, más de 12 años (alveoloplastia secundaria tardía). Para el injerto óseo se utilizó hueso autólogo procedente de cresta ilíaca o calota parietal. Dividimos los pacientes en 2 grupos: grupo I, pacientes con alveoloplastias que precisaron de material de osteosíntesis; grupo II, pacientes que no precisaron de material de osteosíntesis. Parámetros evaluados: los criterios de éxito de la alveoloplastia se valoraron según los parámetros clínicos descritos por Precious. La alveoloplastia era exitosa si cumplían todos los criterios de Precious al año de intervención. Evaluamos las complicaciones postoperatorias en ambos grupos. El análisis estadístico se realizó con el test exacto de Fisher para variables cualitativas. RESULTADOS: El éxito de la alveoloplastia se produjo en el 89,4% de los pacientes del grupo I, mientras que en el grupo II fue del 90,3%. La alveoloplastia fue exitosa en el 87,5% del sexo femenino frente al 91,17% de varones. En el 91,48% de los pacientes del grupo A la intervención fue un éxito frente al 66,6% del grupo B. En 2 pacientes del grupo I el material de osteosíntesis no se degradó en la valoración anual. No existieron diferencias significativas en ninguna de las comparaciones. CONCLUSIONES: La utilización de material de osteosíntesis no altera la integración del injerto óseo en pacientes a los que se realiza alveoloplastia. Factores como el sexo o la edad no influyen tampoco en los resultados de las intervenciones

OBJECTIVES: To compare the results of secondary alveoloplasty performed in one Hospital when osteosynthesis material was used and when the bone graft does not require this material, and relating them to factors such as gender and age. MATERIAL AND METHODS: A retrospective study was conducted from the years 2014 to 2019 in this Hospital on the selected patients who met the inclusion criteria. Two periods of ages, period A: ages between 5-12 years (mixed secondary alveoloplasty) and period B: greater than 12 years (late secondary alveoloplasty). Autologous bone from the iliac crest or parietal calotte was used for the bone graft. The patients were divided into 2 groups: group I: patients with alveoloplasties that required osteosynthesis material. Group II: patients who did not require osteosynthesis material. Parameters evaluated: the success criteria for alveoloplasty were assessed according to the clinical parameters described by Precious. Alveoloplasty was successful if they met all the criteria of Precious in the year of intervention. Postoperative complications in both groups were evaluated. The statistical analysis was performed using the exact Fisher test for qualitative variables. RESULTS: Alveoloplasty was successful in 89.4% of patients in group I, while it was 90.3% in group II. Alveoloplasty was successful in 87.5% of females compared to 91.17% of males. The intervention was a success in 91.48% of patients in group A, compared to 66.6% in group B. The osteosynthesis material in two patients of group I was not degraded in the annual assessment. There were no significant differences in any of the comparisons. CONCLUSIONS: The use of osteosynthesis material does not alter the integration of the bone graft in patients that undergo alveoloplasty. Factors such as gender or age do not influence the results of the interventions

El efecto de la fatiga cíclica sobre los pilares de implantes dentales / The effect of the cyclic fatigue in dental implant abutments

INTRODUCCIÓN: La conexión implante-pilar ha sido sugerida como crucial para el éxito a largo plazo de las restauraciónes sobre implantes oseointegración y para prevenir futuras complicaciónes biológicas y mecánicas. El objetivo de este estudio fué evaluar la influencia del test de fatiga cíclica en el comportamiento de las conexiones internas implante-pilar. MÉTODOS: 36 pilares mutiposición de implantes de titanio de conexión interna fueron divididos en 2 grupos: 18 pilares slim o curvos y 10 pilares rectos con diferentes alturas. Los pilares fueron apretados con una llave de torque a 30 Ncm. Una carga cíclica entre 175 N y 100 N fué aplicada con 30º de inclinación axial al sistema de implantes durante 5 millones de ciclos. RESULTADOS: Los tests biomecánicos muestran una fractura de los implantes y de los tornillos de retención a una carga límite de 100 N de los pilares slim curvos y de 130 N en los pilares rectos. La fracturas aparecieron en la zona de unión entre el cuello y el cuerpo del implante y en los tornillos protéscios. No se han encontrado fracturas en los pilares multiposición. CONCLUSIONES: Este estudio indican que los tests de fatiga cíclica son importantes para analizar la respuesta biomecánica de los diferentes pilares en las conexiones implante-pilar de los sistemas de implantes

INTRODUCTION: The connection implant-abutment has been suggested to be crucial for the long-term success of implant restorations and to prevent future biological and mechanic complications. The aim of this study was to evaluate the influence of fatigue cyclic test in the behavior of internal connection implant-abutments. METHODS: Thirty six titanium abutments of internal connection implants were divided in two groups: 18 slim and 18 right multiunit abutments with different length. Abutments were tightened to 30 Ncm with a torque controller. A cyclic load between 175 N and 100 N according to different implant abutments at a 30-degree angle to the long axis was applied to the implants for a 5 million cycles. RESULTS: Biomechanical testing showed implant and screw retention fracture in a limit load of 100 N of slim implant abutments and 130 N of right implant abutments. Fracture cracks were located in the area between neck and body of implants and screw retention. No abutment fractures were found. CONCLUSIONS: This study indicate that fatigue cyclic test are very important to analize the biomechanical behavior of different abutments in connection implant-abutment of implants systems

Assessing osseointegration of metallic implants with boronized surface treatment

BACKGROUND: Modification of endosteal implants through surface treatments have been investigated to improve osseointegration. Boronization has demonstrated favorable mechanical properties, but limited studies have assessed translational, in vivo outcomes. This study investigated the effect of implant surface boronization on bone healing. MATERIAL AND METHODS: Two implant surface roughness profiles (acid etched, machined) in CP titanium (type II) alloy implants were boronized by solid-state diffusion until 10-15 µm boron coating was achieved. The surface-treated implants were placed bilaterally into 5 adult sheep ilia for three and six weeks. Four implant groups were tested: boronized machined (BM), boronized acid-etched (BAA), control machined (CM), and control acid-etched (CAA). Osseointegration was quantified by calculating bone to implant contact (BIC) and bone area fraction occupancy (BAFO). RESULTS: Both implant types treated with boronization had BIC values not statistically different from machined control implants at t=3 weeks, and significantly less than acid-etched control (p < 0.02). BAFO values were not statistically different for all 3-week groups except machined control (significantly less at p < 0.02). BAFO had a significant downward trend from 3 to 6 weeks in both boronized implant types (p < 0.03) while both control implant types had significant increases in BIC and BAFO from 3 to 6 weeks. CONCLUSIONS: Non-decalcified histology depicted intramembranous-like healing/remodeling in bone for controls, but an absence of this dynamic process in bone for boronized implants. These findings are inconsistent with in vitro work describing bone regenerative properties of elemental Boron and suggests that effects of boron on in vivobone healing warrant further investigation

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Reconstrucción de un defecto de espesor total en ala nasal con malla de titanio / Reconstruction of a Full-Thickness Nasal Alar Defect With a Titanium Mesh

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Comparison of GTR, T-PRF and open-flap debridement in the treatment of intrabony defects with endo-perio lesions: a randomized controlled trial

BACKGROUND: Titanium-prepared platelet rich fibrin (T-PRF) is an autologous hemo-component with a high con-centration of platelets that also incorporates leukocytes, and growth factors into the dense fibrin matrix and can be used as a healing biomaterial. This study assesses the adjunctive use of T-PRF in intrabony defects (IBDs) with open flap debridement (OFD) in comparison with guided tissue regeneration (GTR) as a gold standard and OFD alone as a control. MATERIAL AND METHODS: A total of 45 patients (15 per group) were randomized as either T-PRF (test group), GTR (test group), or OFD alone (control group) sites. Probing depth (PD), clinical attachment level (CAL), and IBD were recorded. The radiographic depth of IBD was also measured. Primary outcomes assessed were changes in PD, CAL, and radiographic IBD that were assessed at the beginning and nine months later. RESULTS: The PRF and GTR group showed significant improvement in clinical parameters compared with the OFD alone (control group) at nine months. While there were no significant differences in PD and CAL between test groups (T-PRF and GTR groups), the significant difference was found in radiographic IBD depth. CONCLUSION: T-PRF may give similar successful results as GTR in the treatment of IBDs with endo-perio lesions

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Descriptive retrospective study analyzing relevant factors related to dental implant failure

BACKGROUND: The objective of this retrospective descriptive study was to analyze the characteristics of incident reports provided by dentists while using a specific brand of dental implants. MATERIAL AND METHODS: The study was carried out in collaboration with Oxtein Iberia S.L.(R), with the company providing access to the incident database in order to evaluate the characteristics of incidents from January 2014 to December 2017 (a total of 917 over four years). The data sheet recorded different variables during each of the stages of implant treatment, from initial implant placement to subsequent prosthetic rehabilitation. These variables included age, sex, systemic pathologies, smoking habits, bone quality, implant type, prosthesis type, and type of load applied, among others. SPSS Statistics was used to perform statistical analysis of the qualitative variables (univariate logistic regressions, χ2 test, Haberman's adjusted standardized residuals). RESULTS: The total study sample consisted of 44,415 implants shipped from Oxtein (R) warehouses on the dates indicated, of which 917 implants (2.1%) were flagged due to reports of lack of primary stability, failed osseointegration, or implant failure within one year of placement. When analyzing incident reports, it was observed that 61.6% of incidents occurred in male patients, compared to 38.4% in female patients. The average age of patients in the reported cases was 56.12 ± 12.15 years. A statistically significant correlation was discovered between incidents of implant failure and tobacco use, diabetes, heart disease, poor oral hygiene, previous infection, poor bone quality, and bruxism (p < 0.05). A (statistically significant) higher rate of incidents was also observed in tapered, internal connection, Grade IV titanium, narrow, and short implants. CONCLUSIONS: Analysis of these implants reveals a higher rate of complication in short, tapered, internal connection and narrow-diameter implants. These data can help and encourage clinicians to use the utmost surgical precautions when placing these implants

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Análisis de degradación de stents metálicos en modelo de cultivo "in vitro" con células epiteliales respiratorias y fibroblastos / Degradation analysis for metal stents in an in vitro cell culture model with respiratory epithelial cells and fibroblasts

Objetivo: investigar la posible degradación de stents metálicos tras co-cultivo con células respiratorias in vitro. Método: durante 21 días se han co-cultivado con la línea CRL-4011 (epitelial) y MRC-5 (fibroblastos) tres tipos de stents: Wallstent(R) (aleación de cobalto-cromo-níquel y molibdeno), Zilver PTX(R) y Zilver Flex(R) (nitinol, aleación de níquel-titanio, con y sin liberación de paclitaxel, respectivamente). Las mismas células sin stent sirvieron como control. Los sobrenadantes de los cultivos se recogieron los días 3, 9, 15 y 21, se alicuotaron y almacenaron a -800 C. Mediante espectrometría de masas (ICP/ MS) se investigaron los niveles de titanio, cromo, níquel, cobalto y molibdeno en los sobrenadantes, y también se han analizado los niveles de esos mismos elementos en el medio de cultivo original (antes de añadirlo a los cultivos celulares). Resultados: en todos los experimentos se encontraron mayores niveles de elementos metálicos en los sobrenadantes recogidos en el tercer día de cultivo, tanto de células epiteliales como de fibroblastos, con diferencias estadísticamente significativas (p<0,002). Los sobrenadantes de los cultivos de células epiteliales con Wallstent mostraron los niveles más altos de níquel y cobalto respecto a los controles (p = 0,001), y los niveles de titanio fueron más altos en los cultivos de Zilver Flex y PTX, constituidos por una aleación de níquel y titanio (p <0,001). Conclusiones: hemos detectado una rápida liberación en el sobrenadante de todos los cultivos de los elementos constitutivos de los tres stents que incluimos en los experimentos, y con niveles muy superiores a los cultivos controles

Objective: To investigate the possible degradation of metal stents after co-culture with respiratory cells in vitro. Methods: Three types of stents were co-cultured with the CRL-4011 line (epithelial) and the MRC-5 line (fibroblasts): Wallstent(R) (cobalt-chromium-nickelmolybdenum alloy), Zilver PTX(R) and Zilver Flex(R) (nitinol, nickel-titanium alloy, with and without paclitaxel release, respectively). The same stentless cells served as the control group. Culture supernatants were collected on days 3, 9, 15 and 21, aliquoted and stored at -80 ºC. The levels of titanium, chromium, nickel, cobalt and molybdenum in the supernatants were studied using inductively coupled plasma mass spectrometry (ICP-MS), and the levels of the same elements were also analyzed in the original culture medium (before adding them to the cell cultures). Results: In all experiments, higher levels of metal elements were found in the supernatants collected on the third day of culture, for both epithelial cells and fibroblasts, with statistically significant differences (p < 0.002). The supernatants of epithelial cell cultures with Wallstent showed the highest levels of nickel and cobalt in comparison to controls (p = 0.001), and titanium levels were higher in Zilver Flex and Zilver PTX cultures, consisting of a nickeltitanium alloy (p < 0.001). Conclusion: We have detected a rapid release in the supernatant of all the cultures of the constituent elements of the three stents that we included in the experiments, and with levels much higher than those of the control cultures

Is the re-use of sterilized implant abutments safe enough? (Implant abutment safety)

Background: The reuse of implant healing abutments is common in dental practice. Effective elimination of bacteria and viruses is accomplished by conventional sterilization. The aim of this work was to explore the eventual survival of microorganisms on sterilized healing abutments and to rule out the presence of transmissible organic material after standard procedures. Material and Methods: A total of 55 healing abutments previously used in patients will be washed and sterilized in a steam autoclave at 121ºC for 15 min. Each healing abutment will be cultured in Brain Heart Infusion broth (BHI) under strict aseptic conditions. Besides, two control groups will be included: one of 3 unused healing abut-ments, and the other of just medium. After 10 days at 37°C under a 5% CO2 100 μl of the broth will be plated on solid media (Brain Infusion Agar, BHIA) and Columbia Blood agar to test for sterility. The remaining volume will be centrifuged, the sediment fixed, and a Gram stain performed to discard the presence of non-cultivable micro-organisms. Moreover, to determine the presence of remaining organic material after the cleaning and sterilizing treatments, the bioburden will be determined by measuring total organic carbon (TOC) in another 10 previously used healing abutments, cleaned and sterilized, that will be submerged in Milli-Q water and sonicated

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Effects of locally applied Insulin-like Growth Factor-I on osseointegration

Background: The aim of this study was to assess the effect of local application of IGF-I on osseointegration of dental implants placed in osteoporotic bones. Material and Methods: 16 rabbits were randomly distributed into two groups: eight animals were ovariectomized and fed a low-calcium diet for six weeks, in order to induce experimental osteoporosis, and the others were sham-operated and fed a standard diet. A titanium implant was inserted into the tibiae in both groups. In half of the rabbits, 4 μg of IGF-I was applied into the ostectomy, prior to the implant insertion. A total of 32 implants were placed. Animals were sacrificed two weeks after surgery and decalcified samples were processed for Bone-To-Implant Contact (BIC) and Bone Area Density (BAD) measurements. Analysis of variance (ANOVA) was used for statistical evaluation. P < 0.05 was considered to be significant. Results: Ovariectomy induced statistically significant lower BAD values (p = 0.008) and a tendency towards lower BIC values when compared osteoporotic and healthy groups. The administration of 4 μg of IGF-I did not produce statistically significant differences neither on BIC nor on BAD values, neither in the osteoporotic animals nor in healthy. Conclusions: Within the limitations of this experimental study, local administration of 4 μg of IGF-I was not able to induce any changes in the osseointegration process two weeks after surgery, neither in healthy rabbits nor in the osteoporotic group

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Effect on osseointegration of two implant macro-designs: A histomorphometric analysis of bicortically installed implants in different topographic sites of rabbit's tibiae

Background: To evaluate the effect of two different implant macro-designs on the sequential osseointegration at bicortically installed implants in the rabbit tibia. A further aim is to compare the osseointegration at different topographic zones. Material and Methods: 27 New Zealand rabbits were implemented. Two implants, one for each macro-design (Ticare Inhex(R) or Ticare Quattro(R), Mozo-Grau, Valladolid, Spain), were randomly implanted in the diaphysis or metaphysis of each tibia. The flaps were sutured to allow a submerged healing. The animals were sacrificed after 2, 4 or 8 weeks. Ground sections were prepared and analyzed. Results: No statistically significant differences were found between the two groups for newly formed bone in contact with the implant surface, being about 16%, 19% and 33% in both groups, after 2, 4, and 8 weeks of healing. Bone apposition was slightly higher in the diaphysis, reaching values of 36.4% in the diaphysis, and 29.3% in the metaphysis at 8 weeks of healing. It was observed that the implant position showed a statistical significance regarding BIC values at 4 and 8 weeks (p < 0.05). Multivariate analysis fails to detect statistical significant differences for the interaction between implant designs and topographic site. Ticare Quattro(R) design had a slight better BIC values at diaphysis sites across healing stages, but without reaching a statistical significance. Conclusions: The both implant macro-designs provided similar degrees of osseointegration. Bone morphometry and density may affect bone apposition onto the implant surface. The apposition rates were slightly better in diaphysis compared to metaphysis

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Development and viability of biofilms grown on experimental abutments mimicking dental implants: An in vivo model

Background: To determine whether an experimental abutment mimicking the macro- and microstructure of a dental implant is a suitable method for recovering biofilm, and to describe the features of biofilms formed around such abutments on healthy implants. Material and Methods: Experimental abutments were used in 15 patients without peri-implant diseases. After 14 days' absence of dental hygiene in this area, the abutments were retrieved and analyzed through confocal laser scanning microscopy and scanning electron microscopy. The biofilm formation on the surface of the first 5 abut-ments was determined by a fluorescence-staining method using SYTO9 nucleic acid stain. In order to study the biofilm's coverage and vitality, 10 additional abutments were assessed using live & dead bacterial viability. Descriptive and bivariate analyses of the data were performed. Results: A global plaque coverage of the abutments was observed in all cases. The submucosal area of the abutment was mostly covered with biofilm (over 21%). Moreover, significant differences between supra- and subgingival locations were detected. Conclusions: This in vivo experimental model allows detailed observation of the extensive plaque growth found on exposed experimental abutments mimicking dental implants when hygiene measures are absent. The biofilm cover-age is significantly higher in the supragingival zone than in the subgingival portion

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Colecciones posquirúrgicas extraaxiales persistentes e infección por Propionibacterium acnes. Presentación de dos casos y revisión de la literatura / Persistent extra-axial post-surgical collections and Propionibacterium acnes infection. Presentation of two cases and literature review

Objetivos: Es frecuente observar la persistencia de colecciones extraaxiales tras craneotomías. La mayoría de estas, desaparecen en semanas o meses pero algunas perduran. La aparición de clínica focal o el crecimiento de estas colecciones persistentes meses o años después de la cirugía pueden indicar la presencia de una infección crónica y latente por gérmenes de baja virulencia como Propionibacterium acnes (P. acnes). Métodos: Presentamos dos casos clínicos con colecciones extraaxiales persistentes, que precisaron cirugía, años después de su diagnóstico, en los que se aisló P. acnes como agente etiológico y revisamos la literatura publicada al respecto. Resultados: Se trata de dos pacientes que posterior a procedimientos quirúrgicos (craniectomía descompresiva por TCE grave y craneotomía por meningioma parietal derecho) desarrollaron colecciones extraaxiales que se mantuvieron vigiladas en el tiempo y que luego se infectaron y precisaron evacuación urgente de las mismas. En estas coleccionas creció el P. acnes como agente causal y precisó antibioterapia dirigida. Conclusiones: Debemos tomar en cuenta al P. acnes como agente infeccioso de colecciones posquirúrgicas de larga evolución. La presentación atípica y los cambios radiológicos pueden ser de ayuda en el diagnóstico

Objectives: It is common to observe the persistence of extra-axial collections after craniotomies. Most of these disappear in weeks or months but some remain. The onset of focal symptoms or the growth of these persistent collections months or years after surgery may indicate the presence of a chronic and latent infection by germs of low virulence such as Propionibacterium acnes (P. acnes). Methods: We present two clinical cases with persistent extra-axial collections, which required surgery years after diagnosis, in which P. acnes was isolated as an aetiological agent and we reviewed the literature published in this regard. Results: These are two patients who, following surgical procedures (decompressive craniectomy for severe TBI and craniotomy for right parietal meningioma) and extra-axial collections were kept, which were monitored over time and then were infected and required emergency evacuation. In these collections P. acnes grew as a causal agent and required targeted antibiotics. Conclusions: We must consider P. acnes as an infectious agent of post-surgical collections of long evolution. Atypical presentation and radiological changes may be helpful in diagnosis

La evaluación topográfica de las superficies de los implantes de titanio / Topographic evaluation of the titanium implant surfaces

La superficie de los implantes es muy importante para la oseointegración. La superficie rugosa de titanio puede influir en los resultados experimentales y clínicos. Diferentes instrumentos y técnicas de mediciones pueden influir notablemente en los resultados de la caracterización topográfica de los implantes. Las superficies han sido documentadas mediante microscopio electrónico de barrido. La interferometría de luz blanca puede identificar las irregularidades en la superficie por cambios en la luz reflejada. La composición química de las superficies puede ser determinada por la técnica de espectroscopía fotoelectrónica de rayos X. La composición química refleja los procedimientos de la fabricación de los implantes. Una variedad de elementos y compuestos químicos no relacionados con la composición del titanio pueden encontrarse en algunos tipos de implantes; como material inorgánico (ej. cloruro de sodio) y compuestos orgánicos de carbono que pueden deberse a la contaminación durante la fabricación y el almacenaje. Conclusiones: Las modificaciones en la topografía y en la composición química de la superficie de los implantes constituye un importante campo en la implantologia oral experimental y clínica

Implant surface is very important for the osseointegration. Roughened surface titanium may influence in experimental and clinical results. Different measures instruments and techniques strongly influence the outcome of a topographic characterization of surface implant. Surfaces has been documented by scanning electron microscopy. White light interferometer may identify the surface irregularities that cause phase changes in the reflected light. The surfaces chemical composition was determined using a technique of X-ray photoelectron spectroscopy. Chemical composition reflect the type of fabrication procedures applied to implants. A variety of elements and chemical compounds not related to the titanium composition were found on some implant types. They ranged from inorganic material (i.e. sodium chloride) to specific organic as carbon compounds believed to be due to contamination during fabrication or storage. The experimental findings are believed to make a contribution to a better understanding of the interplay between industrial fabrication procedure and physico-chemical implant surface properties. Conclusions: The topographic and chemical composition modifications of surface implants constitute an important field in experimental and clinical implant dentistry