RESUMEN
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.
RESUMEN
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.
Asunto(s)
Implantación Dental Endoósea/métodos , Implantes Dentales , Análisis del Estrés Dental/métodos , Animales , Tornillos Óseos , Bovinos , Diseño de Prótesis Dental , Técnicas In Vitro , Estrés Mecánico , Titanio , TorqueRESUMEN
Titanium barriers have been used for guided bone regeneration in preclinical and preliminary clinical reports as a possible alternative to bone grafting. In two cases with lateral bone defects, rigid titanium barriers were used to provide a secluded space in conjunction with bone substitutes. Sufficient lateral bone volume was generated for implant placement, and no complications were observed during 2 years of follow up. In conclusion, space-making stiff titanium barriers may be applied successfully for lateral alveolar crest augmentation.
RESUMEN
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.
Asunto(s)
Huesos/cirugía , Implantes Dentales , Retención de Prótesis Dentales , Animales , Densidad Ósea/fisiología , Bovinos , Materiales Dentales/química , Diseño de Prótesis Dental , Fracaso de la Restauración Dental , Endoscopios/clasificación , Ensayo de Materiales , Movimiento , Estrés Mecánico , Propiedades de Superficie , Factores de Tiempo , Titanio/química , TorqueRESUMEN
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.