Mechanical behavior of single-layer ceramized zirconia abutments for dental implant prosthetic rehabilitation.

OBJECTIVES: This study was undertaken to characterize the mechanical response of bare (as-received) and single-layer ceramized zirconia abutments with both internal and external connections that have been developed to enhanced aesthetic restorations. MATERIAL AND METHODS: Sixteen zirconia implant abutments (ZiReal Post®, Biomet 3i, USA) with internal and external connections have been analyzed. Half of the specimens were coated with a 0.5mm-thick layer of a low-fusing fluroapatite ceramic. Mechanical tests were carried out under static (constant cross-head speed of 1mm/min until fracture) and dynamic (between 100 and 400N at a frequency of 1Hz) loading conditions. The failure location was identified by electron microscopy. The removal torque of the retaining screws after testing was also evaluated. RESULTS: The average fracture strength was above 300N for all the abutments, regardless of connection geometry and coating. In most of the cases (94%), failure occurred by abutment fracture. No significant differences were observed either in fatigue behavior and removal torque between the different abutment groups. CONCLUSIONS: Mechanical behavior of Zireal zirconia abutments is independent of the type of internal/external connection and the presence/absence of ceramic coating. This may be clinically valuable in dental rehabilitation to improve the aesthetic outcome of zirconia-based dental implant systems. Key words:Dental implant, zirconia, ceramic structure, mechanical properties.

Zirconia implant abutments: microstructural analysis.

PURPOSE: Yttria-stabilized zirconia (ZrO2-Y2O3) ceramics have received increasing attention in recent years because of their stress-induced tetragonal-to-monoclinic (martensitic) transformation. This unique process acts as a toughening mechanism, imparting strength and toughness to the ceramic alloy. This property, along with well-documented biocompatibility, is now being exploited in an increasing number of medical applications, including implant dentistry. To prevent clinical problems and predict their behavior and physical limitations, a characterization of the ceramic elements used in dental restorations is essential. The aim of the present study is to characterize the crystal structure, elemental composition, and micr ostructure of asreceived ZiReal Post (Biomet 3i) zirconium oxide abutments, as well as specimens coated with a first layer of a low-fusing fluoroapatite ceramic. MATERIALS AND METHODS: Zirconium oxide abutments, both as-received and porcelain-coated, were studied using the following techniques: x-ray diffraction, x-ray fluorescence, energy dispersive x-ray spectroscopy, optical microscopy, and scanning and transmission electron microscopy. RESULTS: X-ray analyses detected only the presence of Zr, O, Y, and hafnium (Hf), in an amount of 3% to 4% molecular weight Y2O3-ZrO2. X-ray diffraction measurements showed that the ceramic abutment crystallizes mainly in the tetragonal phase, with some residual monoclinic phase. The microstructure is characterized by a rather homogenous grain distribution, formed by equiaxed and fine grains with a mean size of 0.30 Μm. CONCLUSIONS: Compositional and diffraction results are consistent with polycrystalline yttria-stabilized tetragonal zirconia. The material is susceptible to undergoing the stress-induced transformation toughening mechanism because of the very fine grain size. Except for machining ring marks, the surfaces exhibit an excellent finishing quality. No structural modifications were observed in the fluoroapatite ceramic-coated abutments because of the relatively low temperatures used for ceramization compared with the phase transformation temperatures used for zirconia.

Prospective assessment of post-extraction gingival closure with bone substitute and calcium sulphate

Introduction: The closure of post extraction gingival defects has not been studied in depth, although their achievementis of great importance in certain situations, such as prior to radiotherapy treatment in patients with oralcancer. The aim of this study is to assess the influence of bone substitutes on the time of closure of post extraction gingival defects. Materials and Methods: 22 patients underwent two symmetrical dental extractions. Using a split mouth model,with random assignment to one or other group, one was considered a control group (no filling with any type of material post extraction), where as the other was considered the experimental group (filling with bone substituteand calcium sulphate post extraction). Gingival closure and healing were assessed in the first group at 2, 3, 4 and6 weeks after extraction. Results: No differences were seen between both groups in gingival health. Gingival closure was greater and fasterin the experimental group than in the control group, and was statistically significant in the first and second week after extraction (1st week, control: 19.63mm2 ± 2.52 - experimental: 11.76mm2 ± 2.40 - p < 0.05) (2nd week, control:15.09mm2 ± 2.77 - experimental: 7.98mm2 ± 1.99 - p < 0.05), although these differences evened out during subsequent periods. No medical accidents were seen and tolerance to treatment was good in both groups.Discussion: According to our data, the use of filling material allows a faster initial gingival closure of the socketpost extraction. However, we must assess the cost of intervention, with the aim of applying it in situations in whichit may be of significant advantage (for example, patients that will undergo radiotherapy treatment), or in cases in which the use of these materials is justified due to other reasons in addition to the one mentioned (such as maintenance of bone crest architecture for implant restoration) (AU)

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Prospective assessment of post-extraction gingival closure with bone substitute and calcium sulphate.

INTRODUCTION: The closure of post extraction gingival defects has not been studied in depth, although their achievement is of great importance in certain situations, such as prior to radiotherapy treatment in patients with oral cancer. The aim of this study is to assess the influence of bone substitutes on the time of closure of post extraction gingival defects. MATERIALS AND METHODS: 22 patients underwent two symmetrical dental extractions. Using a split mouth model, with random assignment to one or other group, one was considered a control group (no filling with any type of material post extraction), whereas the other was considered the experimental group (filling with bone substitute and calcium sulphate post extraction). Gingival closure and healing were assessed in the first group at 2, 3, 4 and 6 weeks after extraction. RESULTS: No differences were seen between both groups in gingival health. Gingival closure was greater and faster in the experimental group than in the control group, and was statistically significant in the first and second week after extraction (1st week, control: 19.63 mm(2) +/- 2.52--experimental: 11.76 mm(2) +/- 2.40 - p < 0.05) (2nd week, control: 15.09 mm(2) +/- 2.77--experimental: 7.98 mm(2) +/- 1.99 - p < 0.05), although these differences evened out during subsequent periods. No medical accidents were seen and tolerance to treatment was good in both groups. DISCUSSION: According to our data, the use of filling material allows a faster initial gingival closure of the socket post extraction. However, we must assess the cost of intervention, with the aim of applying it in situations in which it may be of significant advantage (for example, patients that will undergo radiotherapy treatment), or in cases in which the use of these materials is justified due to other reasons in addition to the one mentioned (such as maintenance of bone crest architecture for implant restoration).

The application of microscopic surgery in dentistry

El microscopio como herramienta en la práctica de la Medicina, y sobre todo en las especialidades quirúrgicas se ha establecido como un hecho hace ya décadas. Las incorporaciones más tempranas del microscopio a la práctica odontológica debemos buscarla en los años 70 y 80, si bien la incorporación de una forma más amplia (aunque todavía lejos de ser generalizada) ocurre en la década final del siglo pasado. El objetivo del presente artículo es describir las principales aplicaciones del microscopio a la Odontología actual, a la vez que informar y acercar la Odontología realizada bajo microscopia al odontólogo o estomatólogo, ya sea especialista o de práctica general, para lograr una mejor asistencia a sus pacientes. En este trabajo también se trata con especial importancia todos aquellos conceptos necesarios para la consecución de las destrezas manuales necesarias en el uso de la magnificación del campo operatorio por medio del microscopio operatorio (MO)

The use of the microscope as a tool for practising Medicine, especially in surgical specialisations, has been established for decades. The microscope was first used in OdontologyDentistry back to the 1970s and 1980s, and was introduced more widely (although it was still far from being in general use) during 1990s.The purpose of this article is to describe the main applications of the microscope in OdontologyDentistry today, as well as providing odontologists and stomatologists, whether specialists or in general practice, with information about microscopic OdontologyDentistry for better patient care. This work also gives particular importance to matters needed to achieve the necessary manual dexterity to work in a magnified operating field using a surgical microscope (SM)

Transmigración del canino inferior incluido. Presentación de un caso y revisión de la literatura / Transmigration of impacted lower canine. Case report and review of literature

La retención, es decir, la no erupción de un diente permanente más allá de un año después de la edad normal de erupción, es relativamente poco frecuente si exceptuamos el caso de los terceros molares y los caninos superiores. La transmigración se define como el fenómeno en el cual un diente incluido no erupcionado traspasa en más de la mitad de su longitud la línea media. Exponemos el caso clínico de una paciente de 20 años de edad, que presentaba la transmigración del canino inferior izquierdo, con un patrón de migración tipo 4 de Mupparapu. De igual forma, realizamos una revisión bibliográfica de los casos publicados de transmigración, actualizando los principales aspectos de esta patología

Retention, that is, a permanent tooth which is unerupted more than a year after the normal age of eruption, is a relatively rare event, except in the case of the third molars and the upper canines. Transmigration is defined as the phenomenon of more than half an unerupted impacted tooth crossing the midline. We report the clinical case of a twenty-year-old patient presenting transmigration of the lower left canine, with a type 4 transmigration pattern (Mupparapu). Likewise, we carried out a review of the literature of the cases that have been published on transmigration, updating the main aspects of this pathology

Gel de Clorhexidina intra-alveolar en la prevención de la alveolitis tras la extracción de terceros molares inferiores. Estudio piloto / Intra-alveolar Chlorhexidine gel for the prevention of dry socket in mandibular third molar surgery. A pilot study

Introducción: La clorhexidina es un buen agente profiláctico de la alveolitis post-extracción. La aparición del gel bioadhesivo conteniendo clorhexidina al 0,2% podría mejorar esta acción. Su colocación intraalveolar permitiría una actuación más directa sobre el alveolo y una actuación más prolongada del fármaco. Pacientes y método: Presentamos un estudio a simple ciego, randomizado, sobre 30 pacientes, valorando la influencia de la colocación en una sola vez y de forma intraalveolar gel bioadhesivo conteniendo clorhexidina al 0,2% tras la extracción de terceros molares incluidos, en la aparición de alveolitis y en el postoperatorio de los pacientes. Resultados: Encontramos una reducción del 42,65% en la tasa de alveolitis y un postoperatorio más favorable en el grupo experimental. En el grupo control, la alveolitis apareció en un 30,76% frente a un 17,64 % en el grupo experimental. Discusión y conclusiones: Tras comparar nuestros datos con otros estudio, pensamos que el gel bioadhesivo de clorhexidina al 0,2%, aplicado en una sola vez de forma intraalveolar parece ser una opción adecuada para la prevención de la alveolitis. Esta actuación mejora la apertura bucal y el edema en el postoperatorio, aunque son necesarios nuevos estudios realizados a doble ciego y con muestras más amplias para confirmar nuestros datos

Purpose: Chlorhexidine is a good prophylactic agent for post-extraction dry socket alveolitis. The bio-adhesive 0.2% chlorhexidine gel could improve this action since its intra-alveolar positioning would allow a more direct action on the alveolus and more prolonged action of the medication. Materials and Method: We present a single blind, randomised study on 30 patients to evaluate the efficacy of the bio-adhesive 0.2% chlorhexidine gel, placed only once within the alveolus, on the reduction of the incidence of impacted third molar post-extraction dry socket alveolitis and its post-operative effects on patients. Results. A reduction of 42.65% in the occurrence of alveolitis and a more favourable post-operative period in the experimental group was observed. In the control group, the appearance of alveolitis was 30.76% opposite to 17.64 % in the experimental group. Conclusions: The bio-adhesive 0.2% chlorhexidine gel, applied only once after the extraction of impacted third molars, seems to be an appropriate option for the reduction of alveolitis. It improves the buccal aperture and oedema in the post-operative period, although further double blind studies with larger samples are necessary

Transmigration of impacted lower canine. Case report and review of literature.

Retention, that is, a permanent tooth which is unerupted more than a year after the normal age of eruption, is a relatively rare event, except in the case of the third molars and the upper canines. Transmigration is defined as the phenomenon of more than half an unerupted impacted tooth crossing the midline. We report the clinical case of a twenty-year-old patient presenting transmigration of the lower left canine, with a type 4 transmigration pattern (Mupparapu). Likewise, we carried out a review of the literature of the cases that have been published on transmigration, updating the main aspects of this pathology.

Intra-alveolar chlorhexidine gel for the prevention of dry socket in mandibular third molar surgery. A pilot study.

PURPOSE: Chlorhexidine is a good prophylactic agent for post-extraction dry socket alveolitis. The bio-adhesive 0.2% chlorhexidine gel could improve this action since its intra-alveolar positioning would allow a more direct action on the alveolus and more prolonged action of the medication. MATERIALS AND METHOD: We present a single blind, randomised study on 30 patients to evaluate the efficacy of the bio-adhesive 0.2% chlorhexidine gel, placed only once within the alveolus, on the reduction of the incidence of impacted third molar post-extraction dry socket alveolitis and its post-operative effects on patients. RESULTS: A reduction of 42.65% in the occurrence of alveolitis and a more favourable post-operative period in the experimental group was observed. In the control group, the appearance of alveolitis was 30.76% opposite to 17.64 % in the experimental group. CONCLUSIONS: The bio-adhesive 0.2% chlorhexidine gel, applied only once after the extraction of impacted third molars, seems to be an appropriate option for the reduction of alveolitis. It improves the buccal aperture and oedema in the post-operative period, although further double blind studies with larger samples are necessary.

Cirugía de rescate (reubicación quirúrgica) en segundos molares inferiores impactados / Rescue surgery (surgical repositioning) of impacted lower second molars

La impactación de los segundos molares inferiores es una complicaciónde la erupción dentaria muy infrecuente, dado que suincidencia se cifra de un 0,03 a un 0,21 %. Se ha detectado enmayor frecuencia de forma unilateral que bilateral y es más usualen mandíbula que en maxilar. Presenta una ligera predicción porel sexo masculino, y la inclinación mesial es la más habitual.Se han publicado una amplia variedad de aproximaciones terapéuticas,fundamentalmente apelando a técnicas quirúrgicasúnicas o ayudadas de técnicas ortodóncicas, con el objeto dellevar al diente a su correcta posición, y que se engloban bajoel concepto de cirugía de rescate.En los casos resueltos con una reubicación del diente impactado,la extracción profiláctica del germen se ha propugnado comoobligatoria. Presentamos el caso de una paciente de 12 años y6 meses derivado al Master de Cirugía Bucal de la Universidadde Sevilla por presentar falta de erupción del segundo molarinferior izquierdo.El paciente fue derivado por su ortodoncista, quien detecta la impactacióndel diente, antes de iniciar el tratamiento ortodóncico.Dicho compañero nos indica que, si es posible, no extraigamosel germen del tercer molar, pues prevé que será viable su erupciónen el futuro (dispondrá de espacio en la arcada suficiente).Medidos los espacios de que disponemos, decidimos intentarla reubicación del diente impactado sin extraer el germen delcordal, que se llevó a cabo de forma exitosa

The impaction of lower second molars, given that its incidenceis 0.03 to 0.21%, is a rare complication in tooth eruption. Ithas been detected more often in unilateral form than bilateraland is more common in the mandible than in the maxillary. Ithas a slight predilection for males, and mesial inclination ismore usual.A wide variety of therapeutic approaches have been published,basically referring to surgical techniques, independent or complementedby means of orthodontic technical aids, with theaim of placing the tooth in the correct position, and which areencompassed under the concept of surgical rescue.In cases resolved with repositioning of an impacted tooth,prophylactic root extraction has been proposed as obligatory.We present a case of a 12 and a half year old patient referred tothe University of Seville due to non-eruption of the left lowersecond molar.The patient was referred by her orthodontist, who detected theimpaction before starting orthodontic treatment. The orthodontistrequested that, if it was possible, we did not extract the root ofthe third molar, because its eruption would be feasible in thefuture (there would be sufficient space in the arch). The spacesavailable were measured and we decided to attempt the repositioningof the impacted tooth without extracting the root of thewisdom tooth, which was carried out successfully

Rescue surgery (surgical repositioning) of impacted lower second molars.

The impaction of lower second molars, given that its incidence is 0.03 to 0.21%, is a rare complication in tooth eruption. It has been detected more often in unilateral form than bilateral and is more common in the mandible than in the maxillary. It has a slight predilection for males, and mesial inclination is more usual. A wide variety of therapeutic approaches have been published, basically referring to surgical techniques, independent or complemented by means of orthodontic technical aids, with the aim of placing the tooth in the correct position, and which are encompassed under the concept of surgical rescue. In cases resolved with repositioning of an impacted tooth, prophylactic root extraction has been proposed as obligatory. We present a case of a 12 and a half year old patient referred to the University of Seville due to non-eruption of the left lower second molar. The patient was referred by her orthodontist, who detected the impaction before starting orthodontic treatment. The orthodontist requested that, if it was possible, we did not extract the root of the third molar, because its eruption would be feasible in the future (there would be sufficient space in the arch). The spaces available were measured and we decided to attempt the repositioning of the impacted tooth without extracting the root of the wisdom tooth, which was carried out successfully.

Alveolitis seca. Actualización de conceptos / Update on dry socket: A review of the literature

La alveolitis seca es una complicación postoperatoria que acontece tras la extracción dental, quedando definida como una inflamación del alveolo. En el caso que esta inflamación sobrepase las paredes alveolares, estaríamos ante una osteítis localizada. La frecuencia de aparición de la alveolitis se ha referido en un margen muy amplio, desde el 1 % hasta el 70 %. Generalmentese acepta que la mayor incidencia de alveolitis acontece tras la extracción de terceros molares retenidos, en los que la aparición de esta complicación se tasa en un 20-30 % de las extracciones,diez veces más que en el resto de extracciones dentales. En el presente artículo se revisan la forma de aparición clínica,los factores de riesgo relacionados con el cuadro y las teorías etiopatogénicas que intentan explicar su aparición. También se examinan las pautas utilizadas actualmente en su tratamiento. Acorde con las teorías patogénicas de la alveolitis seca, para su prevención se han estudiado agentes fibrinolíticos, lavados, antisépticos y antibióticos. Analizamos los distintos fármacos utilizados, criticando los resultados obtenidos. Como conclusión, y a partir de los datos revisados, pensamos, sin abandonar el territorio de la hipótesis, que es posible defender un modelo patogénico en el que los mecanismos fibrinolíticos bacterianos y del propio organismo colaboren para producir la alveolitis seca

Dry socket is a postoperative complication that occurs after adental extraction and has been defined as an inflammation of the alveolus. If this inflammation should surpass the alveolar walls, it would result in a located osteitis. The frequency of appearance of dry socket has been reported in a very wide margin, from 1%until 70%. It is generally accepted that most dry sockets appear after extraction of third retained molars, in which the occurrence of this complication is about 20-30% of dental extractions, ten times more than in the rest of dental extractions. In this work we review the forms of clinical appearance, the riskfactors related to this affection and the etiopathogenic theories that try to explain its appearance. The treatment management is also examined. Fibrinolitic agents, laundries, antiseptic, and antibiotics have been studied for its prevention, according to the pathogenic theories of dry socket. We analyze and critize the different drugs and their results. In conclusion from the revised data, we think it is possible to defend a pathogenic model in which the bacterial fibrinolytic mechanisms and the microorganism of the own patient may contribute to produce the dry socket

Update on dry socket: a review of the literature.

Dry socket is a postoperative complication that occurs after a dental extraction and has been defined as an inflammation of the alveolus. If this inflammation should surpass the alveolar walls, it would result in a located osteitis. The frequency of appearance of dry socket has been reported in a very wide margin, from 1% until 70%. It is generally accepted that most dry sockets appear after extraction of third retained molars, in which the occurrence of this complication is about 20-30% of dental extractions, ten times more than in the rest of dental extractions. In this work we review the forms of clinical appearance, the risk factors related to this affection and the etiopathogenic theories that try to explain its appearance. The treatment management is also examined. Fibrinolitic agents, laundries, antiseptic, and antibiotics have been studied for its prevention, according to the pathogenic theories of dry socket. We analyze and criticize the different drugs and their results. In conclusion from the revised data, we think it is possible to defend a pathogenic model in which the bacterial fibrinolytic mechanisms and the microorganism of the own patient may contribute to produce the dry socket.

Differential diagnosis and therapeutic approach to periapical cysts in daily dental practice.

The diagnosis and therapeutic approach to periapical cysts is an extremely controversial concern for dentists. Furthermore, as this complaint represents the most frequent cystic lesion of the maxilla, together with the fact that its differential diagnosis with chronic apical periodontitis presents special difficulty, the question takes on even greater importance. The purpose of this article is to assess the validity of the various diagnostic techniques used to differentiate between both pathologies and make a critical analysis of the controversy surrounding the therapeutic approach to suspected periapical cysts through non-surgical and follow-up treatment, or surgical enucleation and histopathological analysis.

Diagnóstico diferencial y enfoque terapéutico de los quistes radiculares en la práctica odontológica cotidiana / Differential diagnosis and therapeufic approach to periapical cysts in daily dental practice

El diagnóstico y enfoque terapéutico de los quistes radiculares supone una cuestión extremadamente controvertida para el odontólogo. Teniendo en cuenta que representa la lesión quística más frecuente de los maxilares, y que su diagnóstico diferencial con la periodontitis apical crónica presenta una especial dificultad, la cuestión adquiere una mayor trascendencia. El objetivo del presente artículo es valorar la validez de las distintas técnicas diagnósticas que nos permiten diferenciar ambas patologías y analizar críticamente la controversia sobre el enfoque terapéutico de los supuestos quistes radiculares hacia una actuación no quirúrgica y de seguimiento, o bien hacia la enucleación quirúrgica y análisis histopatológico de los mismos (AU)