Application of plasmatrix in vertical bone augmentation for implant placement / 口腔疾病防治

@#Vertical bone augmentation surgery still faces considerable challenges in clinical practice due to various problems, such as difficulty in restoring the ideal alveolar bone height and biological complications, and because it is highly technically sensitive. Plasmatrix is derived from patients’ own blood, and it can effectively promote the vascularization of the regenerated area, recruit stem cells, and reduce inflammation when used in vertical bone augmentation. Based on studies published worldwide, this article first divides vertical bone augmentation into 3 categories according to the height of the expected alveolar ridge, namely, type Ⅰ, the required vertical bone gain is less than 4 mm; type Ⅱ, the required vertical bone gain is between 4-8 mm; and type Ⅲ, the required vertical bone gain is greater than 8 mm. In the type Ⅰ vertical bone augmentation, the plasmatrix bone block is directly placed in the defect area and covered with the plasmatrix membrane before tension-free suturing; in the type Ⅱ vertical bone augmentation, the plasmatrix bone block should be placed in the defect area and fixed with titanium nails and then covered with an absorbable collagen membrane and plasmatrix membrane with a tension-free suture; in the type Ⅲ vertical bone augmentation, additional active ingredients (such as bone morphogenetic protein, autologous bone, etc.) should be added to the plasmatrix bone block and strong fixation (such as titanium nails) should be used. Absorbable collagen and plasmatrix membranes should be used to cover the surface of the bone block, and the flap should be sutured. According to different types of vertical bone augmentation categories, the above methods optimize the vertical bone augmentation effect. This article aims to provide a reference and guidelines for oral clinicians to fully understand plasmatrix and simplify the classification and operation of vertical bone augmentation.

Aplication of digitally modified fence technique in vertical bone reconstruction / 口腔疾病防治

Objective@#To propose a digitally modified and guided bone regeneration technique supported by a nonabsorbable titanium plate and explore its effect on vertical bone regeneration.@*Methods@#A total of 8 patients with severe vertical bone defects in the edentulous area who wanted to be treated with implants were included in this study. A digitally modified and guided bone regeneration technique supported by a nonabsorbable titanium plate (fence technique) was used for bone augmentation. The patient's jaw, dentition, and soft tissue data were obtained for prosthetically guided implantation and bone regeneration. After virtual bone augmentation, a model of the jaw was obtained through 3D printing technology, and the titanium plate was bent accordingly. The virtual design was transformed through the template (including the base template and the attachment of a periosteal screw and bone block), so the actual osteogenesis space consistent with the design could be realized in the operation. Guided bone regeneration was performed according to the improved procedure and technical process. After 6 ~ 8 months of bone augmentation, cone beam CT was taken to evaluate the effect of bone augmentation. The implant was implanted according to the initial implant design, and bone tissue was obtained for HE and Masson staining. @* Results@#After 6 ~ 8 months of bone augmentation, the vertical linear bone increment reached (5.44 ± 1.73) mm. The implant was implanted according to the initial implant design, and the bone tissue was obtained for histological examination to show the formation of new bone.@*Conclusion@#Digital improved fence technique can simplify the preoperative and surgical procedures, and obtain good vertical bone augmentation results. In short, it is a kind of vertical bone augmentation technique worth popularizing and applying.

Construction of the animal model of mandibular severe alveolar bone atrophy in Beagle dogs / 口腔疾病防治

Objective @#To establish an animal model that clinically conforms to the characteristics of severe alveolar ridge atrophy. @*Methods @#Beagle dogs were used as experimental subjects. Bilateral fourth premolars and first molars in mandible were extracted. A horizontal groove was made on alveolar ridge which was 8 mm from the cemento-enamal junction of mandible third premolar and second molar. Rongeur was used to remove the alveolar bone above this groove and bone chisel was used to level the bone-free area. A box-shaped defect cavity of the size 25 mm × 8 mm was formed with sterile silicone prosthesis implanted. After careful suture we waited for the subjects to heal naturally. Eight weeks after operation, CBCT examination was performed.@*Results @#Eight weeks after bone remodeling the top of alveolar ridge of operation area appeared to be a circular arc. The average distance from the bottom of the ridge to inferior alveolar nerve canal was 2.5 mm. @*Conclusion @#This study successfully established the Beagle dog animal model for severe alveolar ridge atrophy and laid the foundation for experiments on vertical bone augmentation.

Augmentation of residual alveolar bone height with tissue engineering for dental implant placement.

The challenge of correcting deficient vertical alveolar height for dental implant placement has been there since dental implants came in to regular clinical placement. The ability of various methods to increase the residual alveolar height has met with varying results. The primary reason is that the techniques were not quite successful in maintaining the required residual alveolar height. Use of Bone Morphogentic Protein, especially rhBMP-2 has been met with high degree of success in deficient vertical alveolar height in a mandibular ridge. The demonstration of this using a case has been presented here.

Regeneración ósea guiada para el aumento vertical del reborde alveolar / Guided osseous regeneration for the vertical augmentation of the alveolar ridge

Se considera como aumento óseo vertical, cualquier técnica que apunte a crear una mayor altura del reborde alveolar. A inicios de la década de los 90’s se empezó a utilizar la regeneración ósea guiada (ROG) en mandíbulas atróficas, con el fin de permitir la instalación de implantes óseointegrados. Con el fin de evaluar y exponer parte de la evidencia disponible en la actualidad, con respecto a la ROG para aumento óseo vertical, se realizó la siguiente revisión bibliográfica.

Any technique aimed to improve the alveolar ridge height is considered as a vertical bone augmentation procedure. In the early 90’s guided bone regeneration (GBR) procedures began to be used in atrophic mandibles to allow the installation of osseointegrated dental implants. The following bibliographic review was made with the purpose of evaluating and exposing part of the available evidence at present in this field.