Research on guided bone regeneration (GBR) is still ongoing, with evidence mainly from preclinical studies. Various current barrier membranes should fulfill the main design criteria for GBR, such as biocompatibility, occlusivity, spaciousness, clinical manageability and the appropriate integration with the surrounding tissue. These GBR characteristics are required to provide the maximum membrane function and mechanical support to the tissue during bone formation. In this review, various commercially available, resorbable and non-resorbable membranes with different characteristics are discussed and summarized for their usefulness in preclinical studies. Membranes offer promising solutions in animal models; however, an ideal membrane has not been established yet for clinical applications. Every membrane type presents both advantages and disadvantages. Titanium mesh membranes offer superb mechanical properties for GBR treatment and its current efficacy in trials will be a focus in this review. A thorough understanding of the benefits and limitations inherent to various materials in specific clinical applications will be of great value and aid in the selection of an optimal membrane for GBR.

The aim of this study was to provide an overview on the biology and soft tissue sealing around dental implants and teeth. This is a narrative review performed through scientific articles published between 1977 and 2014, indexed in MEDLINE and PubMed databases. The study selected articles that focused on epithelial sealing around dental implant or teeth with cell biology and histology of soft tissue. Implant therapy has been widely applied in dental rehabilitation for many years, with predictable long-term results. The longevity and functionality of dental implants is dependent on both osseointegration around the implant body and the establishment of a soft tissue barrier that protects the underlying hard tissue structures and the implant itself. The health and stability of the peri-implant mucosa also affects the esthetics of the implant. The healing and maintenance of the epithelial and connective tissues around implants are increasingly recognized as being fundamental to implant success. However, there has been little research into the function or formation of the soft tissue seal around dental implants, and the roles of this unique mucosal interface remain unclear. This narrative review explores the extent of the current knowledge of soft tissue barriers around implants from both a basic and clinical perspective, and aims to consolidate this knowledge and highlight the most pertinent questions relating to this area of research.

Background: The role played by the internal basal lamina (IBL) and hemidesmosomes between an implant and the periimplant epithelium (PIE) in the adherence of the epithelium to the implant is controversial. This study used rat maxilla implantation models to clarify the ultrastructure of the PIE‐implant interface.Methods: Ti‐6Al‐4V implants were inserted either immediately or 2 weeks after the extraction of the upper left first molar of 6‐ or 4‐week‐old rats, respectively. The junctional epithelium (JE) of the upper right molars in the same animals was used as a control. Four weeks after implantation, the animals were sacrificed to prepare specimens for light and immunoelectron microscopy.Results: Under light microscopy, the PIE appeared to attach to the implant surface. Ultrastructurally, IBL, consisting of the lamina densa and lamina lucida, and hemidesmosomes were formed only in the lower region, and rarely in the middle region, of the PIE‐implant interface. In control teeth, the IBL and hemidesmosomes formed throughout the dento‐JE interface. Laminin‐1 was found in the IBL and also in the vesicles and vacuoles of the PIE and JE cells. Statistical analysis showed that there was also a significant difference in the amount of IBL between the PIE‐implant and dento‐JE interfaces.Conclusions: PIE attached to the implant via hemidesmosomes and IBL in the lower region of the PIE‐implant interface. Although PIE cells may secrete laminin‐1, which contributes to epidermal cell adhesion, the PIE which attaches to implants only in the lower region of the interface is considered to be the poorly adhered epithelium. J Periodontol 2000;71:961‐973.