The efficacy of bone reconstructive therapies in the management of peri-implantitis. A systematic review and meta-analysis.

AIM: To evaluate the efficacy of bone reconstructive procedures for the reduction of probing pocket depth (PPD), bleeding on probing (BOP), and suppuration in peri-implantitis-related bone defects at ≥12-month follow-up. MATERIALS AND METHODS: Three databases were searched for randomized controlled trials (RCTs) and controlled clinical trials (CCTs) that compared bone reconstructive therapies to access flap surgery (AFS) (Focused Question-FQ 1), and RCTs, CCTs, and prospective case series that assessed the efficacy of reconstructive therapies (FQ 2). Meta-analysis was performed for FQ1 when more than three studies were identified, while for FQ2 a network was drawn based on RCTs with common treatment arms. RESULTS: Seven RCTs were identified for FQ1 while five RCTs and six prospective case series for FQ2. There was no significant difference in PPD change between AFS and reconstructive surgery (-0.387; p = .325) at 12 months. Furthermore, no clear differences in terms of PPD and BOP changes resulted from the different reconstructive therapies included in the network. Only a small percentage of treated cases with any modality achieved peri-implantitis resolution, as defined by different composite outcomes. CONCLUSIONS: Reconstructive surgery does not offer significant improvements in peri-implant clinical parameters as compared to AFS at 12 months. It was not possible to establish a hierarchy of efficacy among the different biomaterials employed for reconstructive surgery.

Immunomodulation and Biomaterials: Key Players to Repair Volumetric Muscle Loss.

Volumetric muscle loss (VML) is defined as a condition in which a large volume of skeletal muscle is lost due to physical insult. VML often results in a heightened immune response, resulting in significant long-term functional impairment. Estimates indicate that ~250,000 fractures occur in the US alone that involve VML. Currently, there is no active treatment to fully recover or repair muscle loss in VML patients. The health economics burden due to VML is rapidly increasing around the world. Immunologists, developmental biologists, and muscle pathophysiologists are exploring both immune responses and biomaterials to meet this challenging situation. The inflammatory response in muscle injury involves a non-specific inflammatory response at the injured site that is coordination between the immune system, especially macrophages and muscle. The potential role of biomaterials in the regenerative process of skeletal muscle injury is currently an important topic. To this end, cell therapy holds great promise for the regeneration of damaged muscle following VML. However, the delivery of cells into the injured muscle site poses a major challenge as it might cause an adverse immune response or inflammation. To overcome this obstacle, in recent years various biomaterials with diverse physical and chemical nature have been developed and verified for the treatment of various muscle injuries. These biomaterials, with desired tunable physicochemical properties, can be used in combination with stem cells and growth factors to repair VML. In the current review, we focus on how various immune cells, in conjunction with biomaterials, can be used to promote muscle regeneration and, most importantly, suppress VML pathology.