Traditional GBR procedures have been associated with frequent complications and compromised peri-implant esthetics. Tunneling techniques have been proposed as a promising alternative in this regard. More recently, a subperiosteal minimally invasive aesthetic ridge augmentation technique (SMART) was reported to have been clinically successful in a prospective case series. This technique includes the use of a bone graft/recombinant human platelet-derived growth factor-BB combination delivered to the site by a tunneling method. However, published histologic information regarding the nature of the regenerated tissue has been limited. The current study evaluated the histologic and histomorphometric findings of four human specimens harvested at 2, 5, 9, and 14 months after ridge augmentation using the SMART method. Evaluations of the wound healing and bone regeneration sequence over time found that the ridge augmentation was the result of extensive new bone formation that progressed through the woven bone to lamellar bone stages, with remodeling of the xenogeneic graft material and replacement by patient bone. This is the first study utilizing sequential human specimens to histologically examine the chronology of wound healing following alveolar ridge augmentation.

The peri-implant soft tissue seal consists of a connective tissue cuff and a junctional epithelium that is different from the arrangement of periodontium around a natural tooth. However, the peri-implant soft tissue complex lacks Sharpey's fibers, thus offering less resistance to clinical probing and biofilm penetration compared to the natural dentition. Therefore, the proper restorative emergence profile design is essential to facilitate favorable esthetic outcomes and maintain periimplant health. The aim of this article is to review the currently available evidence related to the design of subgingival (critical and subcritical) and supragingival contours of the implant restorative emergence profile (IREP) as well as provide a flowchart for decision-making in clinical practice. Theoretically, the subgingival contours of the crown/abutment complex should mimic the morphology of the root and the cervical third of the anatomic crown as much and as often as possible. However, this is highly dependent upon the three-dimensional spatial position of the implant relative to the hard and soft tissue complex, in addition to the location of the definitive restoration. Frequently, a convex critical contour is required on the facial aspect of a palatally or incisally positioned implant to support an adequate gingival-margin architecture. Conversely, if the implant is placed too far facially, then a flat or concave contour is recommended. In instances where soft tissue support is not needed, the subcritical area may be undercontoured to increase the thickness, height, and stability of the soft tissue cuff.

Traditional guided bone regeneration techniques include flap mobilization and placement of a bone graft, often with the use of space-maintaining devices and cell-occlusive membranes. This approach is associated with frequent complications that negatively affect the outcome of the augmentation and the peri-implant soft tissue esthetics. Although current tunneling techniques have focused on periodontal soft tissue applications, earlier publications described their use for horizontal augmentation of mandibular posterior edentulous ridges in full-denture patients. More recently, the use of recombinant human plateletderived growth factor (rhPDGF-BB) was tested with different bone matrices to treat maxillary anterior edentulous spans. The present case series reports the use of a subperiosteal minimally invasive aesthetic ridge augmentation technique (SMART) to treat 60 single and multiple edentulous, dentate, and implant sites on 21 patients and five treatment categories with a follow-up period ranging from 4 to 30 months. The technique includes the use of a laparoscopic approach to deliver a growth factor/xenograft combination into a subperiosteal pouch. No flap elevation, cell-occlusive membranes, space-maintaining devices, or decortication procedures were used. The results from this case series demonstrated predictable and consistent bone regeneration. The average gain in ridge width for all treatment categories was 5.11 mm (SD 0.76 mm), which compares favorably with previously published reports. Morbidity and complication rates were consistently reduced as well. Human histology results show xenograft particles surrounded by newly formed bone. The role of the periosteum as a source of pluripotent cells in growth factor-mediated bone regeneration is discussed.

The use of immediate placement and loading protocols in implant dentistry has increased during the past several years. However, limited information related to the response of the osseous architecture has been reported. The purpose of this study was to evaluate the fate of the buccal alveolar plate with cone beam computed tomography (CBCT) following lingualized placement of implants into fresh extraction sockets using a flapless surgical approach and immediate nonocclusal loading. A total of 14 patients who required extraction of a single maxillary incisor were selected for this study. CBCT was performed preextraction, at the time of implant placement, and 6 months following implant surgery. The results of this study indicate that resorption of the buccal alveolar plate was not significant. It was therefore concluded that with strict patient selection and appropriate technique, predictable healing can be achieved with lingualized implant placement into fresh extraction sockets and immediate loading. (Int J Periodontics Restorative Dent 2014;34:61-68. doi: 10.11607/prd.1807)