Maxillary sinus floor augmentation using blood without graft material. Preliminary results in 10 patients.

PURPOSE: The maxillary sinus lift is recognized and stable, and there have been different innovations to optimize the technique. The aim of this study was to investigate the maxillary sinus lift technique with the use of a blood clot and without the use of a bone graft. MATERIALS AND METHODS: Ten patients were recruited for a unilateral sinus lift; patients without sinus pathology or other contraindication were selected. The maxillary sinus was accessed conventionally under local anesthesia followed by an osteotomy and a 1-cm(2) bony window access. The sinus membrane was detached and the window was repositioned above and stabilized with a 12- or 14-mm osteosynthesis screw introduced through the alveolar ridge. Dental implants were installed in the second surgical stage. Standardized panoramic radiographic checks were performed at every stage. RESULTS: Seven completely edentulous patients and 3 partially dentate patients were treated surgically. From the first to the second surgery, a bone gain of 2.37 mm was obtained, although loss of bone height was observed in 1 completely edentulous patient. In 7 patients, it was not possible to install the implants owing to insufficient bone height or inadequate bone quality. CONCLUSION: The protocol used in this investigation failed in the bone increase required for implant installation.

[Self-perception of smoking cessation skills among Cardiology residents in Argentina]. / Autopercepción de las habilidades para la cesación del tabaquismo entre los residentes de cardiología en Argentina.

Objective: To evaluate the self-perception of cardiology residents in Argentina regarding their abilities to help their patients stop smoking, as well as their opinions about their knowledge and skills in this area. Materials and methods: A cross-sectional study was carried out using secondary data from a study carried out in five Latin American countries and Spain, focusing on the information provided by cardiology residents in Argentina. Discrete variables were expressed as median and interquartile range, and categorical variables were expressed as percentages, and were analyzed using the chi-square test or Fisher's exact test, depending on the relative frequency of the expected values. Results: 447 residents participated; 87.5% routinely provided brief advice to quit smoking, and 11.6% used validated questionnaires to assess the degree of addiction. Furthermore, 32.1% stated that they prescribed pharmacological treatment, but 53.1% were only familiar with a single drug. When asked about their self-perception of getting their patients to stop smoking, the median response was 5 (scale from 1 to 10); only 13.7% responded with a score of 8 or more. Conclusions: The present study suggests that cardiology residents in Argentina recognize the importance of carrying out smoking cessation interventions, but a high proportion of them do not feel qualified to do so.

Relationship between mysticism and severe odontogenic infections in Africa: what to do?

OBJECTIVE: This study is a case report of a severe odontogenic infection treated at Huambo Provincial Hospital, Angola. The case was made worse by local mysticism. CASE REPORT: A pregnant woman was treated for a severe odontogenic infection that caused descending mediastinitis and even a lumbar abscess. The patient died of this infection. A delay in attendance was crucial in this death. DISCUSSION: Patients from the African continent commonly experience life-threatening head and neck infections. These critical infections are rarely found in Europe or North America. The clinical situation is aggravated by local mysticism, along with poverty, lack of access to health facilities, and a shortage of skilled workers. Religious habits and the use of local herbs without scientific evidence can create difficult-to-manage situations. CONCLUSIONS: The authors believe this is the first report of an association between life-threatening odontogenic infection and mysticism. International collaboration, including teledentistry and continuing education, are critical to transforming this scene.

Retraction: Bacterial adhesion and colonization differences between zirconia and titanium implant abutments: an in vivo human study.

[This retracts the article on p. 217 in vol. 42, PMID: 23346465.].

Mechanical evaluation of the use of conventional and locking miniplate/screw systems used in sagittal split ramus osteotomy.

OBJECTIVES: The aim of this study was to compare the mechanical resistance of four different osteosyntheses modeled in two different sagittal split ramus osteotomy (SSRO) designs and to determine the linear loading in a universal testing machine. MATERIALS AND METHODS: An in vitro experiment was conducted with 40 polyurethane hemimandibles. The samples were divided into two groups based on osteotomy design; Group I, right angles between osteotomies and Group II, no right angles between osteotomies. In each group, the hemimandibles were distributed into four subgroups according to the osteosynthesis method, using one 4-hole 2.0 mm conventional or locking plate, with or without one bicortical screw with a length of 12.0 mm (hybrid technique). Each subgroup contained five samples and was subjected to a linear loading test in a universal testing machine. RESULTS: The peak load and peak displacement were compared for statistical significance using PASW Statistics 18.0 (IBM Co., USA). In general, there was no difference between the peak load and peak displacement related to osteotomy design. However, when the subgroups were compared, the osteotomy without right angles offered higher mechanical resistance when one conventional or locking 2.0 mm plate was used. One locking plate with one bicortical screw showed higher mechanical resistance (162.72±42.55 N), and these results were statistically significantly compared to one conventional plate with monocortical screws (P=0.016) and one locking plate with monocortical screws (P=0.012). The difference in peak displacement was not statistically significant based on osteotomy design or internal fixation system configuration. CONCLUSION: The placement of one bicortical screw in the distal region promoted better stabilization of SSRO. The osteotomy design did not influence the mechanical behavior of SSRO when the hybrid technique was applied.

An in vitro comparison between two different designs of sagittal split ramus osteotomy.

OBJECTIVES: To evaluate the influence of the type of osteotomy in the inferior aspect of the mandible on the mechanical performance. MATERIALS AND METHODS: The study was performed on 20 polyurethane hemimandibles. A sagittal split ramus osteotomy (SSRO) was designed in 10 hemimandibles (group 1) with a vertical osteotomy in the buccal side (second molar level) and final osteotomy was performed horizontally on the lingual aspect, while the mandible body osteotomy was finalized as a straight osteotomy in the basilar area, perpendicular to the body. For group 2, the same osteotomy technique was used, but an oblique osteotomy was done in the basilar aspect of the mandibular body, forming continuity with the sagittal cut in the basilar area. Using a surgical guide, osteosynthesis was performed with bicortical screws using an inverted L scheme. In both groups vertical compression tests were performed with a linear load of 1 mm/min on the central fossa of the first molar and tests were done with models made from photoelastic resin. Data were analyzed using Student's t-test, establishing a statistical significance when P <0.05. RESULTS: A statistical difference was not observed in the maximum displacements obtained in the two osteotomies (P <0.05). In the extensiometric analysis, statistically significant differences were identified only in the middle screw of the fixation. The photoelastic resin models showed force dissipation towards the inferior aspect of the mandible in both SSRO models. CONCLUSION: We found that osteotomy of the inferior aspect did not influence the mechanical performance for osteosynthesis with an inverted L system.

LeFort I segmented osteotomy experience with piezosurgery in orthognathic surgery.

The aim of this work was to present the LeFort I segmented osteotomy in consecutive patients using the piezoelectric system. A descriptive study was designed for patients operated on between November 2012 and January 2014. All the patients presented some type of skeletal anomaly and underwent orthognatic surgery via piezoelectric osteotomies. Each maxillary surgery was developed with that system and those patients who also received osteotomies with a reciprocating saw were excluded. Surgical time and complications were analyzed. 19 patients underwent surgery consecutively with an osteotomy average time of 45 minutes. The patients operated on at the beginning were longer surgeries, whereas the final cases were 40 minutes. No type of laceration of vascular elements or laceration of palatal tissue was observed. The protocol was fully implemented, incorporating all the advantages of piezoelectric systems. It is concluded that the LeFort I segmented osteotomy can be performed with low risk of injuring soft tissues and in a time probably less than 50 minutes for the maxillary osteotomy.

Influence of the design in sagittal split ramus osteotomy on the mechanical behavior.

The aim of this study was to determine the influence of the design of the sagittal split ramus osteotomy (SSRO) on the mechanical resistance to vertical forces. An in vitro study was designed for 30 test specimens. Two osteotomy models were made on two polyurethane hemimandibles, where group I presented a SSRO with an angle at vestibular level between both molars and group II presented a linear SSRO towards the basilar border. In both groups a standard osteosynthesis was performed with a 2.0 system plate and four monocortical screws, establishing sub-groups according to the degree of mandibular advancement: group A without advancement, group B with an advancement of 3 mm, and group C with advancement of 7 mm. Hemimandibles were subjected to a vertical load in the Instron machine until reaching peak load with failure, recording the value of the load and displacement. The data were analyzed with a t-test to establish statistical significance, considering p<0.05. The results showed that group II presented the best response to the compressive load, tolerating the highest load values. These results were observed in almost all the groups with statistically significant differences (p<0.05). By contrast, group I presented torsional forces prior to reaching system failure. It can be concluded that the osteotomy design influences mechanical resistance and that the linear SSRO offers the best mechanical resistance.

A descriptive study of the oral status in subjects with Sjögren's syndrome.

Sjögren's Syndrome (SS) is an autoimmune pathology of varying prevalence. Its involvement in exocrine glands requires that greater attention be paid to patients' oral health. A cross-sectional study was designed to assess the oral health of subjects with SS in constant medical follow-ups. Variables such as the presence of periodontal infections, decay and alterations in the oral mucosa were analyzed, and the individual's salivary flow was measured. The data were analyzed descriptively and with the chi-squared test, considering p<0.05 as statistically significant. 35 subjects of both sexes were studied, aged between 25 and 82 years, with an age average of 53.9 years; they presented on average 7.9 years after the initial diagnosis. The subjects reported a dental check-up every 6 months in only 9% of cases, whereas the rest had one every 1 or 2 years. All the subjects recounted presenting with dry mouth and associated significantly the ingestion of fluids and teeth brushing to improve the sensation of dryness. The salivary flow was objectively seen to be compromised, showing a significant reduction in those with more time since diagnosis of the disease; more than 90% of subjects exhibited periodontal inflammation and a high level of caries. The mucosa presented a low level of pathology. In conclusion, education in oral health is imperative for subjects with this pathology and more frequent check-ups may be useful in decreasing the levels of oral pathology.

TMJ function after partial condylectomy in active mandibular condylar hyperplasia.

Condylar hyperplasia is a frequent pathology that causes severe facial asymmetries. The partial condylectomy generally halts the disease. The aim of this research was to examine post-condylectomy TMJ function; 14 patients were included in this study, 6 male and 8 female. The average age was 21 years old. In all, the partial condylectomy was performed with preauricular or endaural access and the osteotomy were performed with drills, saw or an ultrasonic system. The patients were assessed with 3 or more time after surgery and were considering maximum mouth opening, right and left lateralities, presence of pain, noises, alterations in the facial nerve (VII) and esthetic alteration from the scar. The analysis was performed with the visual analog scale (VAS) and with a 7 cm metallic rule. Data analysis was descriptive plus chi-square test considering p value < 0.05 for statistical differences. With an average of 11 month after surgery, the results showed that the open mouth (over 35 mm) and lateralities (average 9 mm for the both right and left side) were normal and without statistical differences between the right or left side. Noise was observed in 3 patients and pain was observed in two patients with level 2 and 1 (VAS score). Scar was not related to problem with patient and the temporal branch of facial nerve was observed with limitations but without problem for patients. It can be concluded that the condylectomy is a safe and effective procedure with low morbidity for patients.

Photoelastic evaluation of two different sagittal split ramus osteotomies in advancement surgery.

The aim of this study was to establish the influence of the design of the sagittal split ramus osteotomy (SSRO) on stress distribution on the osteosynthesis in a photoelastic resin model. Two polyurethane hemimandibles were used to perform the osteotomies, tilted in the lateral sector of the first/second molar (group I) and the other descending downwards and laterally from the first molar (group II), with no higher angle. Six replicas of each were made in photoelastic resin and stabilized with a plate and 5 mm monocortical screws in a standardized way. Stabilization was done in the SSRO without advancement, with 3 mm advancement and with 7 mm advancement. Compressive loads were applied at the level of the lower first molar in an Instron machine (model 4411) with a speed of 1 mm/min until reaching 3 mm of displacement, at which point the data was recorded with a camera to identify the stress distribution bands. The results showed stress distribution in different places: for group I it was observed mainly in the screws of the proximal segment, being more intense closer to the osteotomy; in group II I it was observed mainly in the screws of the proximal segment furthest from the osteotomy, also being distributed towards the upper area of the plate. It may be concluded that under standard osteosynthesis conditions, modifications to the SSRO produce changes in the location and distribution of stress.

Bacterial contamination along implant-abutment interface in external and internal-hex dental implants.

The aim of this research was to evaluate bacterial contamination along the implant-abutment interface in relation to the size of the interface. 80 brand name implants were used, 40 internal-hex and 40 external-hex. The implants were handled in a sterile atmosphere inside a box, where they were inoculated with 0.3 µl of the Streptococcus sanguis ATCC10556 bacterium in the interior and the abutment was immediately installed with a torque of 30 Ncm for the external-hex and 20 Ncm for the internal-hex; the system was included in an Eppendorf control for 30 seconds and then placed in an Eppendorf control for 30 days. The implants were removed and assessed under a scanning electron microscope while the Eppendorf controls were bred in blood agar to analyze the colonies formed. The data were analyzed using the Chi-squared, Kruskal-Wallis and Mann-Whitney tests, considering a value of p<0.05 to obtain statistical significance. Five implants were excluded due to probable external contamination. Microspaces of up to 86.8 µm were observed in the external-hex implants and up to 53.9 µm in the internal-hex implants with no significant differences between the different systems being observed (p>0.05). The contamination observed was produced mainly in the external-hex implants and statistically significant differences were observed between the different hex systems from the same company. No significant differences were observed between interface size and bacterial contamination. Within our limitations, there was no relation between the size of the implant-abutment interface and bacterial contamination with Streptococcus sanguis ATCC10556.

Pattern and treatment of mandible body fracture.

The aim of this research was to study of treatment of mandibular body fractures (MBF). A retrospective study of 66 patients with mandibular body fracture was realized with subjects was present clinical and image diagnosis;were analyzed socio-demographic variables, etiology, sign and symptoms of fracture, type of treatment and complications. Was executed a statistical and descriptive analysis with Chi-square with statistical significance with p<0.05. The average age was 34 year with 55 male patient; the more common etiology were physical violence and motorcycle accident. The 45.5% present only MBF; patients with multiple fractures show clinical relations between MBF and contra lateral mandibular angle fracture; 54 patients were treated with open reduction without statistical relations with symptoms (p=0.244) or displacement of fracture (p=0.309); the 54.2% of surgical cases present an extraoral approach, using the intraoral approach when the fracture present poor displacement (p=0.0074); the complications more common were suture dehiscence and infections of surgical site. We conclude that the initial choose of treatment was not related to variables analyzed; when exist a minor displacement of MBF can be indicated an intraoral approach for reduction and fixation technique.

New bone formation in a bone defect associated to dental implant using absorbable or non-absorbable membrane in a dog model.

The aim of this research was to determine the bone formation capacity in fenestration defects associated with dental implants using absorbable and non-absorbable membranes. Six dogs were used in the study. In both tibias of each animal 3 implants were installed, and around these 5 mm circular defects were created. The defects were covered with absorbable membranes (experimental group 1), non-absorbable membranes (experimental group 2), and the third defect was not covered (control group). At 3 and 8 weeks post-surgery, the animals were euthanized and the membranes with the bone tissue around the implants were processed for histological analysis. The statistical analysis was conducted with Tukey's test, considering statistical significance when p<0.1. Adequate bone repair was observed in the membrane-covered defects. At 3 weeks, organization of the tissue, bone formation from the periphery of the defect and the absence of inflammatory infiltrate were observed in both experimental groups, but the defect covered with absorbable membrane presented statistically greater bone formation. At 8 weeks, both membrane-covered defects showed adequate bone formation without significant differences, although they did in fact present differences with the control defect in both periods (p>0.1). In the defects without membrane, continuous connective tissue invasions and bone repair deficiency were observed. There were no significant differences in the characteristics and volume of the neoformed bone in the defects around the implants covered by the different membranes, whereas the control defects produced significantly less bone. The use of biological membranes contributes to bone formation in three-wall defects.

Implante de zircônia em dentes posteriores em extração imediata / Zirconia implant in posterior teeth in immediate extraction

Os implantes de zircônia estão sendo usados com maior frequência na atualidade. Considerando suas vantagens e desvantagens, necessita-se de uma curva de aprendizado para que sejam instalados, uma vez que existem limitações em relação à versatilidade da questão protética, devido ao fato de seu corpo carregar junto o munhão protético. Dessa forma, o presente estudo tem como objetivo relatar um caso clínico em que foram realizadas exodontia e instalação imediata do implante em zircônia, assim como ativação de função estética imediata e, posteriormente, a reabilitação protética em cerâmica. Para isso se utilizou implante de zircônia da marca Straumann (Suiça) e reabilitação protética final com dissilicato de lítio. Os resultados apontam a eficácia na reabilitação e resultados estéticos favoráveis, especialmente, no que tange à cicatrização óssea e adaptação de tecidos moles, assim como na função mastigatória. Ressalta-se ainda a importância da curva de aprendizado do cirurgião, desenvolvimento de um desenho cônico dos implantes para estabilidade primária em tecidos ósseos com densidade III e IV, além de outros estudos na área (AU).

Zirconia implants are currently being more frequently used. Considering their advantages and disadvantages, a learning curve is necessary for them to be installed, as there are limitations related to the versatility of the prosthetic matter, due to the fact that its body carries together the prosthetic abutment. So the present study aims to report a clinical case in which was performed exodontia and immediate implantation of the zirconia implant, as well as activation of immediate aesthetic function, and after that prosthetic ceramics rehabilitation. To perform this, a zirconia implant of the brand Straumann (Switzerland) and final prosthetic rehabilitation with lithium disilicate were used. The results point to rehabilitation efficacy and favorable aesthetic results, particularly in regard to bone healing and soft tissue adaptation, as well as in masticatory function. It is also worth noting the importance of the surgeon learning curve, the development of implants conical design for primary stability in bone tissues with density III and IV, besides other studies in the area (AU).

Bacterial adhesion and colonization differences between zirconia and titanium implant abutments: an in vivo human study.

PURPOSE: Several parameters have been described for determining the success or failure of dental implants. The surface properties of transgingival implant components have had a great impact on the long-term success of dental implants. The purpose of this study was to compare the tendency of two periodontal pathogens to adhere to and colonize zirconia abutments and titanium alloys both in hard surfaces and soft tissues. METHODS: Twelve patients participated in this study. Three months after implant placement, the abutments were connected. Five weeks following the abutment connections, the abutments were removed, probing depth measurements were recorded, and gingival biopsies were performed. The abutments and gingival biopsies taken from the buccal gingiva were analyzed using real-time polymerase chain reaction to compare the DNA copy numbers of Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, and total bacteria. The surface free energy of the abutments was calculated using the sessile water drop method before replacement. Data analyses used the Mann Whitney U-test, and P-values below 0.05 find statistical significance. RESULTS: The present study showed no statistically significant differences between the DNA copy numbers of A. actinomycetemcomitans, P. gingivalis, and total bacteria for both the titanium and zirconia abutments and the biopsies taken from their buccal gingiva. The differences between the free surface energy of the abutments had no influence on the microbiological findings. CONCLUSIONS: Zirconia surfaces have comparable properties to titanium alloy surfaces and may be suitable and safe materials for the long-term success of dental implants.

Variation in the repair of a rib graft used for mandibular reconstruction after 20 years / Variación en la reparación de un injerto costal utilizado para reconstrucción mandibular después de 20 años

Mandibular reconstruction has been used in the last 100 years as a safe, effective and stable technique. Various types of grafts have been used, including the autogenous rib graft; the normal repair of this type of graft has been defined in some studies although some observations have been made indicating low predictability of the growth of this bone. The aim of this study was to report the case of a patient with a rib graft for mandibular reconstruction where after 20 years cartilaginous tissue was observed exclusively in the absence of bone tissue. A 61-year-old female patient presented in the Oral and Maxillofacial Surgery Service for dental implants. The patient had a history of 4 previous mandibular reconstructions; imaging showed no alterations to the normal evolution of a graft. However, the intraoral access contained softer tissue than the normal bone, and thus the implant installation was abandoned. Histopathological analysis revealed the formation of collagenous tissue and cartilage, chondrocytes island conditions characteristic of cartilaginous tissue in the absence of mineralization and cancellous bone. This led to the conclusion that repair conditions can vary based on specific and general factors as yet under discussion.

La reconstrucción mandibular ha sido utilizada en los últimos 100 años como una técnica segura, eficaz y estable. Diversos tipos de injertos se han utilizado siendo el auto trasplante de hueso costal uno de ellos; la normal reparación de este tipo de injertos ha sido definida en algunas investigaciones aunque se han realizado otras observaciones indicando baja predictibilidad del crecimiento de este hueso; el objetivo de esta investigación es reportar un caso de una paciente portadora de injerto costal para reconstrucción de mandíbula donde después de 20 años se observó exclusivamente tejido cartilaginoso en ausencia de tejido óseo. Una paciente del sexo femenino, 61 años se presentó al Servicio de Cirugía Oral y Maxilofacial para ser tratada con implantes dentales; la paciente presentaba historia de 4 reconstrucciones mandibulares previas; los estudios de imagen se presentaban sin alteraciones a la condición normal de la evolución. Sin embargo, al acceso intraoral se observó un tejido más blando que el hueso normal, abortándose la instalación del implante. El análisis histopatológico reveló la formación de tejido colágeno y cartílago, condrocitos en lagunas y condiciones características de tejido cartilaginoso en ausencia de mineralización y trabeculado óseo.Se concluye que las condiciones de reparación pueden variar en base a factores específicos y generales aun en discusión.

Stress analysis in maxillary all-on-four model / Análisis del estrés en un modelo maxilar del concepto all-on-four

The aim of this research was to evaluate the load distribution in tilted distal implants used in the all-on-four system. Two implant schemes were used. In both, two vertical anterior implants and tilted posterior implants were installed, one group with an angulation of 15 and another with an angulation of 35. The implants were installed together with a bar binding them all in a photoelastic model obtained from a replica of an edentulous maxilla. In this model, loads were produced in the sector of the bar cantilever, the abutment of the tilted implants and over the four implants using devices specially designed for this purpose. The bands were recorded with a digital camera, and the qualitative and quantitative analyses were carried out by means of student's t-test and the Mann-Whitney test in Biostat v. 5.0, considering a level of p<0.05 to establish a statistically significant relation. In the qualitative analysis, the implant with 35 presented the greatest amount of stress on the cantilever forces at cervical level. The quantitative studies showed fewer differences in all aspects assessed, although significant differences were observed between the two systems when loads were applied at cantilever level. It can be concluded that there are minimal differences in the stress distribution when comparing implants with angulations of 15 or 35. However, there is a greater concentration of stress at the cervical level in implants tilted to 35.

El objetivo de esta investigación fue evaluar la distribución de cargas en implantes angulados distales utilizados en el sistema "All-On-Four". Dos esquemas de implantes fueron empleados. En ambos, dos implantes verticales en el área anterior y dos implantes angulados en el sector posterior fueron instalados, utilizando angulaciones de 15 y 35 o en estos últimos. Los implantes fueron instalados de forma conjunta mediante una barra unida al sistema de resina fotoelástica obtenida de una replica de una maxila edéntula. En este modelo, las cargas fueron producidas en el sector del cantiléver de la barra, el pilar del implante angulado y, mediante un sistema genérico, sobre la totalidad de los implantes. Las bandas de estrés fueron reconocidas en una cámara digital donde los análisis cualitativos y cuantitativos fueron realizados utilizando las pruebas t de Student y Mann-Whitney en el programa computacional Biostat v. 5.0, considerando un valor de p<0,05 para establecer diferencias significativas. En el análisis cualitativo, los implantes con 35 presentaron una gran cantidad de estrés en el área de cantiléver, principalmente a nivel cervical. Los estudios cuantitativos mostraron limitadas diferencias en todos los aspectos, aunque diferencias significativas fueron alcanzadas cuando se compararon ambos sistemas después de la carga a nivel del cantiléver. Se puede concluir que hay diferencias menores en la distribución de estrés cuando se comparan implantes dentales con angulación de 15 y 35. Sin embargo, existe una mayor cantidad de concentraciones de estrés a nivel cervical en los implantes con 35 de angulación.

Is there a difference in the resonance frequency values obtained directly on the implants and abutments? / ¿Existe diferencia en la frecuencia de resonancia obtenida directamente en los implantes y pilares?

The aim was to evaluate the differences of implant stability quotient (ISQ) between implants with external hexagon and Morse taper connectors. The study had a split mouth design, composed by 10 patients who received hybrid protocol prosthesis. In total, 40 implants (3.75 x 13 mm) were installed: on the right side, 20 external hexagon, and on the left, 20 Morse taper. After two years in function, the stability test was applied by using the MRI machine Osstell ISQ directly on the implants and on the abutments. Considering the measurements made on the implants, there were differences between HE and CM mesial (p= 0.011), lingual (p= 0.003) and distal (p= 0.006). Considering the measurements made on the abutments, there were differences between HE and CM on the buccal (p= 0.020) and lingual (p= 0.004). The trend and higher values are for the CM group. The values for Morse taper implants were always higher in a statistically significant manner, when compared to the external hexagon.

El objetivo fue evaluar las diferencias del coeficiente de estabilidad de implantes comparando los de conexión de hexágono externo (HE) y cono morse (CM). El estudio tuvo un diseño de boca dividida, siendo compuesta por 10 pacientes que recibieron protocolos protésicos de tipo hibrido. En total, 40 implantes (3,75x13 mm) fueron instalados: en el lado derecho, 20 implantes de hexágono externo y en el lado izquierdo, 20 implantes de cono morse. Después de dos años en función, la prueba de estabilidad fue aplicada utilizando una maquina MRI, Ostell ISQ directamente sobre los implantes y pilares. Considerando las medidas en los implantes, hubo diferencias entre los implantes HE y CM en mesial (p= 0,011), lingual (p= 0,003) y distal (p= 0,006). Considerando las medidas en los pilares, hubo diferenciasentre HE y CM en el sector bucal (p= 0,020) y lingual (p= 0,004). Los valores mas altos se obtuvieron en CM; los valores de las conexión tipo cono morse presentaron mayor estabilidad al comparase con los implantes de conexión de hexágono externo.

Electroterapia para la regeneración ósea de implantes dentales / Electrotherapy for bone regeneration in dental implants

La oseointegración se ha optimizado favorablemente en los últimos años y tecnologías variadas se han aplicado para mejorar esta condición. El objetivo de esta investigación fue conocer la relación entre la aplicación de cargas eléctricas y su capacidad de mejorar la oseointegración en un modelo animal. 16 conejos de raza New Zealand, de 3 a 6 meses, fueron divididos en dos grupos. En ambos se realizo la instalación de 4 implantes de titanio especialmente diseñados para esta investigación, dos en cada tibia, utilizando técnicas de compresión. En el grupo experimental se aplico cargas eléctricas a nivel de extremidades inferiores durante 30 minutos por día mientras duraba el tiempo previo a la eutanasia de los animales realizada finalmente a los 21 y 42 días, momento en el cual fue realizada la prueba de torque de retiro con un torquímetro manual; posteriormente, los bloque con los implantes fueron retirados y se procesaron con técnicas histológicas de rutina para la tinción de Hematoxilina y Eosina; se realizo una observación descriptiva mediante microscopia óptica y los resultados numéricos fueron analizados con el análisis de varianza y posteriormente utilizando el test F con un nivel de significancia de 5%. Los resultados mostraron diferencias significativas en el torque de retiro de implantes a los 21 días y a los 42 días; no se observaron diferencias significativas entre el grupo control y el grupo experimental; histológicamente, no se observaron diferencias en el patrón de osificación, la disposición de elementos u otras condiciones histológicas de la reparación. Se puede concluir que la administración de cargas eléctricas en este modelo experimental no contribuye a la formación de tejido óseo perimplantar.

Osseointegration has been optimized in the last years; differents technologies has been applied to improve this condition. The aim of this research is to understand the relationship between the application of electric charges and their ability to improve osseointegration in an animal model. Sixteen New Zealand white male rabbits, 3 to 6 months of age, were divided into two groups. In both was inserted a 4 titanium implants designed for this research, two on each tibia; compression techniques was conducted for to install the implant. In the experimental group electric charges at the level of lower limbs was applied for 30 minutes per day; the euthanasia of the animals was performed at 21 and 42 days, at which time was obtained the measurement of the retirement torque with a manual torque wrench; subsequently, the blocks with implants were removed and processed with routine histological techniques with hematoxylin and eosin; a descriptive observation was performed by optical microscopy and the numerical results were analyzed by analysis of variance and then using the F test with a significance level of 5%. The results showed significant differences in removal torque of implants at 21 and 42 days; no significant differences between the control group and the experimental group were observed; Histologically, no differences in elements disposition or other histological repair conditions were observed. It can be concluded that the administration of electric charges in this experimental model does not contribute to the formation of perimplant bone tissue.