Propiedades osteoinductivas de la dentina en regeneración ósea. Estudio preliminar / Osteoinductive properties of the dentin in bone regeneration. Preliminary study

Introducción: El concepto de preservación alveolar está relacionado con los procedimientos llevados a cabo tras realizar una exodoncia dentaria con el fin de reducir la reabsorción dentro del alvéolo. La dentina ha sido propuesta como un biomaterial para este fin. Este artículo tiene como propósito evaluar la efectividad de la dentina en la preservación alveolar y contrastar sus propiedades. Material y Método: Se presentan como parte de un estudio en desarrollo los primeros casos tras realizar exodoncias múltiples. Determinamos un alveolo de estudio preservado con dentina y un alveolo control en el que estabilizamos el coagulo. La estabilidad dimensional de ambos alveolos se valoró mediante CBCT pasadas 8 y 16 semanas. Tras este periodo colocamos dos implantes experimentales de superficie Bioecth®. A las 16 semanas fueron explantados con trefina y sustituidos por implantes convencionales. Estas muestras fueron analizadas histológica e histomorfomètricamente. Resultados: En el análisis tomográfico apreciamos mayor estabilidad dimensional en el lado estudio. Histológicamente observamos ausencia de células inflamatorias, o signos de reacción a cuerpo extraño, además de partículas de dentina completamente rodeadas de hueso neoformado, y frentes osteogènicos partiendo de partículas de dentina. Discusión: Los resultados obtenidos a partir de este estudio en humanos están en consonancia con lo que ha sido descrito en la literatura. Observamos a nivel tomográfico menor variación dimensional en los alveolos donde se llevó a cabo la preservación con dentina particulada, estos resultados sumados al análisis histológico contrastan las propiedades descritas para injertos particulados de dentina no desmineralizada, biocompatibilidad, osteoconducción y osteoinducción. (AU)

Introduction: The concept of alveolar preservation is related to the procedures carried out after performing a tooth extraction in order to reduce resorption within the alveolus. Dentin has been proposed as a biomaterial for this purpose. The aim of this article is to evaluate the effectiveness of dentin in alveolar preservation and to contrast its properties. Material and Method: The first cases are presented as part of a work in progress study after multiple extractions. It is determined a study socket preserved with dentin and a control socket in which the clot is stabilized.The dimensional stability of both sockets was assessed by CBCT after 8 and 16 weeks. After this period, two experimental Bioecth® surface implants were placed. After 16 weeks these were explanted with trephine and replaced with conventional implants. The samples were analyzed histologically and histomorphometrically. Results: In the tomographic analysis it was observed greater dimensional stability on the study side. It was noted the absence of inflammatory cells, or signs of foreign body reaction in the histology. In addition, dentin particles were completely surrounded by newly formed bone, and appeared osteogenic fronts associated with these particles. Discusion: The results obtained from this study in humans are in line with what has been described in scientific papers. At the tomographic level, it was observed less dimensional variation in sockets where the preservation with particulate dentin was carried out. These results added to the histological análisis, contrast the properties described for particulate grafts of non-demineralized dentin, biocompatibility, osteoconduction and osteoinduction. (AU)

Is clinical experience important for obtaining the primary stability of dental implants with aggressive threads? An ex vivo study

Background: The aim of this study was to investigate the clinicians' experience on maintaining the primary stability of implants with aggressive threads belonging to a novel dental implant system. Material and Methods: Three hundred implants with aggressive threads were inserted in fresh bovine ribs mimicking Type IV bone by five clinicians which were classified according to their previous experience of total number of implant insertion. An independent examiner measured the primary stability of all implants after insertion by using resonance frequency analysis (RFA), electronic percussive testing (EPT) and removal torque methods. Results: No significant differences were detected between the stability values measured by the clinicians (p> 0.05) except the Periotest values (PTVs) of the non-experienced clinician. PTVs of the non-experienced clinician were significantly higher than the PTVs of the expert and good clinicians (p<0.05). Significantly higher stability values were detected in the secondary insertion of the non-experienced clinician as compared to her initial insertion values (p<0.05). No significant differences were detected between the first and second measurements of the other clinicians (p> 0.05). Conclusions: Within the limitations of this ex-vivo study, it may be concluded that experience does not play an important role in maintaining the stability of implants with aggressive threads

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La biología de la oseointegración en los implantes postextraccion / The biology of osseointegration in postextraction implants

Los fenómenos biológicos de la oseointegración comprenden un proceso de reabsorción y formación ósea que ha sido descrito en estudios histológicos en animales y humanos. La extracción de dientes seguida de la inserción de implantes inmediatos provoca alteraciones en las dimensiones del hueso alveolar con gaps horizontales y verticales entre las paredes del alveolo y el implante. La reabsorción de la pared vestibular parece ser más pronunciada. Esta deshicencia ósea despues de la inserción de implantes postextracción ha sido corroborada en experimentos con animales y confirmada en studios clínicos con pacientes. Diversos factores pueden afectar a la respuesta biológica de los tejidos periimplantarios y el contacto hueso-implante en los alveolos postextracción como la densidad de hueso, la superficie y el diseño del implante y la técnica quirúrgica. Conclusión: La investigación experimental y clínica indica que la inserción de implantes en alveolos frescos no perjudica la remodelación de los tejidos periimplantarios. Sin embargo, tiene lugar la reabsorción ósea tanto de la pared vestibular como lingual

The biology of osseointegration involve a process of healing with bone resorption and bone apposition, as described histologically in animal and human studies. The removal of teeth followed by immediate implant placement results in marked alterations to alveolar ridge dimensions as well as horizontal and vertical gaps between the bone walls and the implant. Resorption of the buccal plate was seen to be more pronounced; this bone dehiscence following implant placement corroborates findings reported in animal experiments and confirmed in clinical studies with patients. Several factors affecting the biologic response of peri-implant tissues and bone-implant contact in postextraction implants as original bone density, implant surfaces, implant design and surgical technique. Conclusions: Experimental and clinical research studies suggest that the insertion of implant in fresh sockets does not jeopardize remodeling of periimplant tissues. However, bone resorption can be expected on both the lingual and buccal aspects

La oseointegración de implantes de titanio con diferentes superficies rugosas / Osseointegration of titanium implant with several rough surfaces

La superficie de los implantes es muy importante para conseguir la oseointegración. Existen muchos tipos de superficies en los implantes dentales. La investigación en superficie de implantes comienza con la superficie mecanizada. La superficie rugosa incrementa la adherencia celular y muestra una mayor área de contacto hueso-implante. El recubrimiento con plasma de titanio e hidroxiapatita fueron métodos comunes para modificar la rugosidad de la superficie. Más recientemente, el arenado (ej. alúmina) y el grabado ácido (ej. chorhídrico, sulfúrico, nítrico) son otros procesos que pueden incrementar la superficie rugosa de los implantes. Más recientemente, la tecnología ha comenzado en la implantología oral con el desarrollo de superficies porosas que manifiestan una mejor respuesta osteogénica e incrementa la unión mecánica hueso-titanio. La oseointegración parece estar influenciada por los modelos de especies animales. En el conejo el proceso es más rápido que en el perro, y en el perro es más rápido que en el hombre. La incorporación de nuevos materiales y procesos técnicos en la investigación sobre superficies de implantes ofrecen nuevas posibilidades de mejorar su respuesta tisular y su potencial óseo regenerativo. Conclusiones: El tratamiento de la superficie de los implantes constituye un importante campo en futuras investigaciones de la implantología oral mediante los estudios de experimentación

Implant surface is very important for enhance the osseointegration. They are many types of dental implant surfaces. Implant surface research begins with machined surface. Roughened surface titanium increase cell adhesion and exhibit stronger bone-implant contact area. Plasma-spray and hydroxyapatite coating were common methods for rough surface modification. Most recently, blasting (i.e. alumina) and acid-etching (i.e. hydrochloric, sulphuric and nitric) are another process by which surface roughness can be increased. Most recently, technology begins in implant dentistry with the development of porous surfaces that manifest better osteogenic response and increase bone-titanium mechanical interlocking. Osseointegration appeared to be strongly influenced by the animal species model. The rabbit model was faster compared to the dog model, and the dog model was faster the human model. The introduction of new materials and new technical process in dental surfaces research offering new possibilities for better tissue response and bone regenerative potential. Conclusions: The surface modifications of titanium constitute an important field for future research of implant dentistry by experimental studies

Findings from the experience with the punch technique for auditory osseointegrated implants: A retrospective single center comparative study / Resultados de la experiencia con la técnica de perforación para implantes auditivos osteointegrados: estudio comparativo retrospectivo de nuestro centro hospitalario

Objective: To compare the punch technique and linear incision with soft tissue reduction for the placement of auditory osseointegrated implants (AOI) and analyze results of osseointegration obtained with the punch technique as measured with the Implant Stability Quotient (ISQ). Methods: Case review of 34 patients who received auditory osseointegrated implants between January 2010 and July 2015 and were divided into two groups according to the surgical technique: 18 with the punch technique (PT) and 16 with the linear incision technique (LI). Minimum follow-up was four months (mean: 24 months; range 4-64 months). Included in the analysis were patient profiles and records of the demographic data, surgical indications, surgical technique, implant placement, surgical time, intraoperative complications, as well as postsurgical complications (Holgers classification) and implant stability quotients (ISQ). Results: Use of larger abutments was significantly greater in the PT group (PT, 10 mm; LI, 6 mm, p < 0.001). The PT technique resulted in a shorter procedure than the LI (PT, 20 min; LI, 45 min, p < 0.001). Holgers classification scores identified significantly fewer skin complications one week after surgery for the PT group; however, only small differences were seen between the two groups at the one- and three-month control visits. Conclusions: As shown for our cohort, the punch technique for surgical placement of AOI is faster and presents fewer immediate postoperative complications when compared to the linear incision technique. The clinical application of the ISQ is a useful, easy method to demonstrate the status of osseointegration and, thus, the stability of the device (AU)

Objetivo: Comparar la técnica de perforación con la de incisión lineal con reducción de tejidos blandos en la colocación de implantes osteointegrados y analizar los resultados de la osteointegración obtenidos con la técnica de perforación (PT) medidos con el coeficiente de estabilidad del implante (Implant Stability Quotient [ISQ]). Métodos: Treinta y cuatro pacientes recibieron implantes osteointegrados entre enero 2010 y julio 2015, dividiéndolos en 2 grupos: 18 con PT y 16 con técnica de incisión lineal (LI). El seguimiento mínimo fue de 4 meses (media: 24 meses; rango 4-64 meses). Analizamos los perfiles de los pacientes, datos demográficos, indicaciones quirúrgicas, técnica quirúrgica, colocación del implante, tiempo de cirugía, complicaciones intraoperatorias y postoperatorias (clasificación de Holgers) y el ISQ. Resultados: El uso de pilares más largos fue significativamente mayor en el grupo PT (PT: 10mm; LI: 6mm, p < 0,001). La PT fue más corta que la LI (PT: 20 min; LI: 45 min, p < 0,001). La clasificación Holgers identificó menos complicaciones cutáneas a la semana poscirugía en el grupo PT de forma significativa; de hecho, solo se apreciaron pequeñas diferencias entre los 2 grupos en las visitas al mes y los 3 meses. Conclusiones: Como se muestra en nuestro estudio, la PT para la colocación de implantes osteointegrados es más rápida y presenta menos complicaciones cutáneas postoperatorias inmediatas cuando se compara con la técnica LI. La aplicación clínica del ISQ es útil y fácil para objetivar la osteointegración y así la estabilidad del implante (AU)

Valoración audiológica y subjetiva del dispositivo Baha(R) Attract / Audiologic and subjective evaluation of Baha(R) Attract device

Se incluyeron en el estudio 9 pacientes implantados con el dispositivo Baha(R) Attract. A todos los pacientes se les realizó, con y sin el dispositivo, una audiometría tonal en campo libre, una audiometría verbal en campo libre, y una audiometría verbal con ruido de fondo, así como la aplicación de los cuestionarios Glasgow Benefit Inventory (GBI) y Abbreviated Profile of Hearing Aid Benefit (APHAB). Las valoraciones audiológicas con el dispositivo mostraron unos umbrales auditivos promedios de 35,8 dB, con ganancias medias de 25,8 dB. El umbral de recepción verbal promedio con el dispositivo se situó en 37 dB, mostrando una ganancia de 23 dB. Los resultados promedio del umbral de discriminación máxima fueron de 60 dB con el dispositivo. El Baha(R) Attract logra alcanzar unas ganancias auditivas en los pacientes indicados correctamente, con una consiguiente valoración subjetiva positiva por parte de los pacientes, presentando no obstante un efecto atenuativo en su transmisión transcutánea, que le impide alcanzar mayores ganancias (AU)

We included 9 patients implanted with Baha(R) Attract. All our patients were evaluated by free field tonal audiometry, free field verbal audiometry and free field verbal audiometry with background noise, all the tests were performed with and without the device. To evaluate the subjective component of the implantation, we used the Glasgow Benefit Inventory (GBI) and Abbreviated Profile of Hearing Aid Benefit (APHAB). The auditive assessment with the device showed average auditive thresholds of 35.8 dB with improvements of 25.8 dB over the previous situation. Speech reception thresholds were 37 dB with Baha(R) Attract, showing improvements of 23 dB. Maximum discrimination thresholds showed an average gain of 60 dB with the device. Baha (R). Attract achieves auditive improvements in patients for whom it is correctly indicated, with a consequent positive subjective evaluation. This study shows the attenuation effect in transcutaneous transmission, that prevents the device achieving greater improvements (AU)

The effects of surgical preparation techniques and implant macro-geometry on primary stability: An in vitro study

BACKGROUND: The attainment of a good primary stability is a necessary condition to ensure the success of osseointegration in implantology. In type IV cancellous bone, however, it is possible that a reduced primary stability can lead to an increased rate of failure. The aim of this study was therefore to determine, with the help of the resonance frequency (Osstell mentor), which technique of implant site preparation (piezo surgery, conventional, under-preparation, bone compaction, osteodistraction) and macro-geometry is able to improve implant stability in type IV cancellous bone. MATERIAL AND METHODS: 10 pig ribs were prepared with a surgical pre-drilled guide, calibrated for a correct implant positioning. On each rib, 5 implant sites (one for each technique) were prepared. Successively, 50 conical implants (Tekka Global D) were inserted and measured with the resonance frequency to evaluate the primary stability. Data collected were analyzed by analysis of variance (ANOVA) to test whether the Implant Stability Quotient (ISQ) values of the five techniques were significantly different. RESULTS: The results showed that no significant differences among the ISQ values of the five techniques used were found. Also, no significant differences in the macro-geometry of the two types of compared implants were observed. However, the macro-geometry of Tekka implants, characterized by a double condensing thread, seems to provide greater ISQ values than those of single thread implants when using the same technique. CONCLUSIONS: In light of these preliminary data, it is conceivable that in cases of reduced stability, such as those occurring with a type IV bone, all means ameliorating the primary stability and accelerating the osseointegration can be utilized