Bone Augmentation in Rabbit Tibia Using Microfixed Cobalt-Chromium Membranes with Whole Blood and Platelet-Rich Plasma.

BACKGROUND: Bone augmentation is a subject of intensive investigation in regenerative bone medicine and constitutes a clinical situation in which autogenous bone grafts or synthetic materials are used to aid new bone formation. METHOD: Based on a non-critical defect, Co-Cr barrier membranes were placed on six adult Fauve de Bourgogne rabbits, divided into two groups: whole blood and PRP. Three densitometric controls were performed during the experiment. The animals were euthanized at 30, 45, 60, and 110 days. The presence of newly formed bone was observed. Samples for histological studies were taken from the augmentation center. RESULTS: External and internal bone tissue augmentation was observed in almost all cases. Significant differences between PRP- and whole blood-stimulated bone augmentation were not observed. At 60 days, bones with PRP presented higher angiogenesis, which may indicate more proliferation and cellular activity. CONCLUSION: PRP activates the bone regeneration process under optimized conditions by stimulation of osteoblast proliferation after six weeks, when a significant difference in cellular activity was observed. Membranes could stimulate bone augmentation at the site of placement and in the surrounding areas.

Influence of implant diameter in the displacement of dental implants in trabecular bovine bone under a static lateral load: experimental results and computational modeling.

PURPOSE: Primary stability and micromovement of dental implants depend on structural properties of the surrounding bone and on implant dimension and design. The purpose of this study was to provide objective data for the influence of implant diameter on the displacement of titanium screw implants. MATERIALS AND METHODS: Ninety Semados implants (length 15 mm, diameter 3.25, 3.75, and 4.5 mm; Bego, Bremen, Germany) were inserted in trabecular bone specimens. All implants were inserted with a torque up to 30 N·cm and loaded horizontally with 10, 20, and 30 N for 2 seconds. RESULTS: All implants showed primary stability. With increasing force, a gradual increase of micromovement was observed (Kruskal-Wallis test, P = 0.000). No significant differences were found (Kruskal-Wallis test, P = 0.148) comparing different diameters for every force. CONCLUSIONS: Variation of the diameter of standard implants between 3.25 and 4.5 mm does not seem to influence the primary stability in trabecular bone specimen. Differences between experimental and computational results may be due to the simplification used when modeling.

Displacement of dental implants in trabecular bone under a static lateral load in fresh bovine bone.

AIM: The study aims to provide objective data for the displacement of titanium screw implants in trabecular bone specimens. One hundred Semados implants (Bego, Bremen, Germany) were inserted in bovine type IV bone specimens. All implants had a diameter of 3.75 mm; 50 implants had a length of 8.5 mm and 50 implants had a length of 15 mm. Insertion torque was determined at intervals of 10, 20, and 30 Ncm. Implants were loaded horizontally with 10, 20, and 30 N for 2 seconds. An indicator strip was attached to the implant abutment to allow direct observation of implant movement relative to the bone surface. Horizontal displacement was assessed with an accuracy of measurement of 10 µm. Seven implants got lost by visible loosening. Degree of displacement was subject to evaluation with all others. Those implants showed a mean displacement of 59 µm for 10 N (n = 100), 173 µm for 20 N (n = 99), and 211 µm for 30 N (n = 93). The mean displacement of 15-mm implants (16, 37, 51 µm) was significantly lower compared with 8.5-mm implants (103, 311, 396 µm) corresponding to 10, 20, and 30 N as lateral loads. CONCLUSIONS: Displacement of screw implants in trabecular bone can be detected and visualized using commercially available endoscopes with a high magnification. A lateral load of 20 N indicates a mean displacement of over 100 µm and therefore results in a critical displacement.

Immediate loading of freestanding implants using cortical satellite implants: 3-year results of an ongoing prospective study.

BACKGROUND: It has previously been demonstrated that immediate full occlusal loading of freestanding anterior implants can be performed using cortical satellite implants, obtaining a success rate similar to conventional protocols. The aim of this report was to present the outcomes after 36 months after initial placement. METHODS: Twenty patients received 2 single-standing titanium screw implants, which were stabilized during healing time with cortical satellite implants. Immediately after surgery, mandibular overdentures were placed using ball attachments. The satellite implants were removed after 3 months. RESULTS: Implant survival analysis showed a 100% success rate. The following parameters were assessed during the study: Periotest values, -5.89 (minimum: -7.00, maximum: -4.00); radiographic assessment of bone resorption, 0.51 mm (minimum: 0.00 mm, maximum: 1.50 mm); and pocket probing depth, 2.60 mm (minimum: 1.00 mm, maximum: 8.00 mm). CONCLUSIONS: The results suggest that immediate loading of freestanding implants stabilized with satellite implants is a successful concept at 3 years observation time.

Immediate occlusal loading of freestanding implants using cortical satellite implants: preliminary report of a prospective study.

Freestanding implants with mandibular overdentures are used frequently after 3 months' healing time. Immediate full loading may be applied to this approach if sufficient primary stability is provided. The present study evaluates the success rate of two single-standing interforaminal implants stabilized with cortical satellite implants and loaded immediately with overdentures. Twenty patients (five male and 15 female; age, 45-87 years) received two single-standing titanium screw implants (Semados, Bego, Bremen, Germany). All implants were stabilized during healing time with cortical satellite implants (2.0-mm bone screws; Medartis, Basel, Switzerland) via individual connectors attached to the implant abutment subgingivally. Mandibular overdentures were incorporated immediately after surgery using ball attachments as retentive elements. The patients were under no restrictions concerning diet and loading. The satellite implants were removed after 3 months. All implants were osseointegrated after 10 months' mean observation time. The mean Periotest value was -4.9, and the mean marginal bone loss was 0.7 mm. No dropouts were observed, and 19 of 20 patients would recommend the treatment to a close friend. Preliminary follow-up data indicate that cortical stabilization of two anterior mandibular implants with satellite implants leads to osseointegration of the implants under immediate load conditions with an overdenture. This concept contributes to reduction of prosthetic treatment costs and permits immediate enhancement of masticatory function.

In vitro evaluation of horizontal implant micromovement in bone specimen with contact endoscopy.

Primary stability of dental implants is mandatory for their osseointegration. A method is described that allows objective measurements of implant displacement in bone sites during lateral loading. Ten samples of bovine bone (2 cm x 2 cm) with bone type II, III, and IV according to Lekholm and Zarb were used for the experiment. Ten Semados dental implants of 15-mm length and 3.75-mm diameter were placed. All implants were loaded with lateral forces of 5, 10, 20, and 30 N through 8-mm abutments for 2 seconds each. Lateral displacement was observed by means of contact endoscopy. Micromovement was detected with the help of a transmitter strip attached to the abutment. Endoscopic images were processed digitally and microdisplacement was calculated relative to the reference body (microscrew) placed adjacent to the implant. Micromovement observed varied with the force applied. Lateral force of 5 N resulted in a mean displacement of 39 microm; for 30 N, the mean displacement was 157 microm. Bone type also influenced the amount of movement. Contact endoscopy represents a new method for direct observation of implant movement relative to the bone surface in vitro. In combination with support immersion technique, contact endoscopy could be used as an office procedure to evaluate intraoperatively implant stability during functional loading.

Elevacion del seno maxilar controlada endoscopicamente / Sinus augmentation controled by endoscopy

La elevacion del seno ha sido recomendada por ser una tecnica quirurgica con unos resultados predecibles en cirugia periimplantaria. La cirugia endoscopica del seno maxilar hasta la fecha se ha utilizado como procedimiento de diagnostico. En este trabajo, el uso de la endoscopia se describe como una tecnica de ayuda poco evasiva en la elevacion del piso del seno. Tras la preparacion de la mucosa del seno, se colocan injertos oseos bajo control endoscopico entre el piso del seno y la mucosa. La elevacion de la mucosa y la colocacion del injerto se hacen posibles mediante un abordaje laterobasal a traves de una pequeña osteotomia y un abordaje transalveolar. Se han informado los primeros resultados clinicos. La elevacion endoscopica del seno puede contribuir a la reduccion de la morbilidad perioperativa, a una reduccion de las fistulas oroantrales y al control de la posicion del injerto. Una tecnica menos invasiva puede permitir la extension de las indicaciones para elevacion del seno

Reconstrucción alveolar primaria con microfijación y colocación de implantes / Primary alveolar reconstruction with microfixation and implants placement

Proponemos esta técnica de regeneración alveolar para el sector anterior, específicamente para la zona del primer premolar a primer premolar en maxilar superior, sobre todo cuando el hueso en esa zona no es lo suficientemente ancho. Se realiza la disyunción del reborde alveolar y a continuación colocamos implantes cilíndricos roscados. LUego fijamos la tabla vestibular con placa de titanio y microtornillos