Intestinal macrophages in pathogenesis and treatment of gut leakage: current strategies and future perspectives.

Macrophages play key roles in tissue homeostasis, defense, disease, and repair. Macrophages are highly plastic and exhibit distinct functional phenotypes based on micro-environmental stimuli. In spite of several advancements in understanding macrophage biology and their different functional phenotypes in various physiological and pathological conditions, currently available treatment strategies targeting macrophages are limited. Macrophages' high plasticity and diverse functional roles-including tissue injury and wound healing mechanisms-mark them as potential targets to mine for efficient therapeutics to treat diseases. Despite mounting evidence on association of gut leakage with several extraintestinal diseases, there is no targeted standard therapy to treat gut leakage. Therefore, there is an urgent need to develop therapeutic strategies to treat this condition. Macrophages are the cells that play the largest role in interacting with the gut microbiota in the intestinal compartment and exert their intended functions in injury and repair mechanisms. In this review, we have summarized the current knowledge on the origins and phenotypes of macrophages. The specific role of macrophages in intestinal barrier function, their role in tissue repair mechanisms, and their association with gut microbiota are discussed. In addition, currently available therapies and the putative tissue repair mediators of macrophages for treating microbiota dysbiosis induced gut leakage are also discussed. The overall aim of this review is to convey the intense need to screen for microbiota induced macrophage-released prorepair mediators, which could lead to the identification of potential candidates that could be developed for treating the leaky gut and associated diseases.

Biomechanical and radiological assessment of immediate implants for alveolar ridge preservation.

BACKGROUND: The aim of this study was to evaluate the stability of immediate implant placement for alveolar bone augmentation and preservation with bovine bone graft following atraumatic tooth extraction. MATERIALS AND METHODS: This was a prospective interventional study with convenient sampling (n = 10). Thirty patients aged between 18 and 40 years, who needed noncomplicated tooth extraction of mandibular premolar tooth, were sequentially divided equally into three groups. In Group I, simple extraction was done and the empty extraction socket left to heal conventionally. In Group II, extraction sockets were filled with lyophilized bovine granules only. In Group III, immediate implants were placed into extraction sockets, and the buccal gap was also filled with bovine granules. All groups were subjected to cone beam computed tomography scan for radiological evaluation. Assessment of biomechanical stability (radiofrequency analysis [RFA] was performed at 9 months postoperative for Group III to assess the degree of secondary stability of the implants using Osstell. Repeated measure analysis of variance (ANOVA) test was applied when comparing within each group at three different time intervals, whereas one-way ANOVA was applied followed by post hoc-tukey test when comparing between groups. P < 0.05 was considered statistically significant. RESULTS: Radiological assessment reveals a significant difference of bone resorption in alveolar dimension within Group I; 1.49 mm (P = 0.002), and 0.82 mm (P = 0.005), respectively, between day 0 and 3 months. Comparison between Group I and III showed a highly significant difference of bone resorption in ridge width at 3 months 2.56 mm (P = 0.001) and at 9 months interval 3.2 mm (P < 0.001). High RFA values demonstrating an excellent biomechanical stability were observed in Group III at 9 months postoperatively. CONCLUSION: The insertion of immediate implants in extraction sockets with bovine bone augmentation of the buccal gap was able to preserve a greater amount of alveolar ridge volume.

Three-Dimensional Radiological Assessment of Alveolar Bone Volume Preservation Using Bovine Bone Xenograft.

INTRODUCTION: Alveolar bone is critical in supporting natural teeth, dental implants as well as a removable and fixed prosthesis. Alveolar bone volume diminishes when its associated natural tooth is lost. OBJECTIVE: The aim of this study is to evaluate the effectiveness of bovine bone granules on alveolar bone socket augmentation for ridge preservation following atraumatic tooth extraction. MATERIALS AND METHODS: Twenty medically fit patients (12 males and 8 females aged between 18 and 40 years) who needed noncomplicated tooth extraction of 1 mandibular premolar tooth were divided randomly and equally into 2 groups. In control group I, the empty extraction socket was left untreated and allowed to heal in a conventional way. In group II, the empty extraction socket wound was filled with lyophilized bovine bone xenograft granules 0.25 to 1 mm of size, 1 mL/vial. A resorbable pericardium membrane was placed to cover the defect. Clinical and 3-dimensional radiological assessments were performed at day 0, 3 months, and 9 months postoperative. RESULTS: There were no clinical differences in general wound healing between the groups. Comparisons within the groups showed a significant difference of bone resorption of 1.49 mm (95% confidence interval, 0.63-2.35) at 3 months, and further resorption of 1.84 mm (P ≤ 0.05) at 9 months in the control group. No significant changes of bone resorption were observed in group II during the same time interval. Comparison between groups showed a significant difference of bone resorption at 3 and 9 months (2.40 and 2.88 mm, respectively). CONCLUSION: The use of lyophilized demineralized bovine bone granules in socket preservation to fill in the extraction socket seems essential in preserving the alveolar bone dimension as it showed excellent soft and hard tissue healing. This study concludes that the alveolar bone socket exhibited a dynamic process of resorption from the first day of tooth extraction. Evidence shows the possibility of using bovine bone granules routinely in socket volume preservation techniques following tooth extraction.