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Periodontology 2000 Oct 2023The morphology and dimensions of the postextraction alveolar ridge are important for the surgical and restorative phases of implant treatment. Adequate new bone... (Review)
Review
The morphology and dimensions of the postextraction alveolar ridge are important for the surgical and restorative phases of implant treatment. Adequate new bone formation and preservation of alveolar ridge dimensions following extraction will facilitate installation of the implant in a restorative position, while preservation of soft tissue contour and volume is essential for an aesthetic and implant-supported restoration with healthy peri-implant tissues. Alveolar ridge preservation (ARP) refers to any procedure that aims to: (i) limit dimensional changes in the alveolar ridge after extraction facilitating implant placement without additional extensive bone and soft tissue augmentation procedures (ii) promote new bone formation in the healing alveolus, and (iii) promote soft tissue healing at the entrance of the alveolus and preserve the alveolar ridge contour. Although ARP is a clinically validated and safe approach, in certain clinical scenarios, the additional clinical benefit of ARP over unassisted socket healing has been debated and it appears that for some clinicians may represent an overtreatment. The aim of this critical review was to discuss the evidence pertaining to the four key objectives of ARP and to determine where ARP can lead to favorable outcomes when compared to unassisted socket healing.
Topics: Humans; Alveolar Ridge Augmentation; Tooth Extraction; Alveolar Process; Tooth Socket; Overtreatment; Alveolar Bone Loss
PubMed: 37622682
DOI: 10.1111/prd.12508 -
Cell Jul 2023Wnt ligands oligomerize Frizzled (Fzd) and Lrp5/6 receptors to control the specification and activity of stem cells in many species. How Wnt signaling is selectively...
Wnt ligands oligomerize Frizzled (Fzd) and Lrp5/6 receptors to control the specification and activity of stem cells in many species. How Wnt signaling is selectively activated in different stem cell populations, often within the same organ, is not understood. In lung alveoli, we show that distinct Wnt receptors are expressed by epithelial (Fzd5/6), endothelial (Fzd4), and stromal (Fzd1) cells. Fzd5 is uniquely required for alveolar epithelial stem cell activity, whereas fibroblasts utilize distinct Fzd receptors. Using an expanded repertoire of Fzd-Lrp agonists, we could activate canonical Wnt signaling in alveolar epithelial stem cells via either Fzd5 or, unexpectedly, non-canonical Fzd6. A Fzd5 agonist (Fzd5) or Fzd6 stimulated alveolar epithelial stem cell activity and promoted survival in mice after lung injury, but only Fzd6 promoted an alveolar fate in airway-derived progenitors. Therefore, we identify a potential strategy for promoting regeneration without exacerbating fibrosis during lung injury.
Topics: Mice; Animals; Lung Injury; Wnt Proteins; Frizzled Receptors; Wnt Signaling Pathway; Alveolar Epithelial Cells; Stem Cells
PubMed: 37321220
DOI: 10.1016/j.cell.2023.05.022 -
Nature Communications Oct 2023Acute exposure to high-dose gamma radiation due to radiological disasters or cancer radiotherapy can result in radiation-induced lung injury (RILI), characterized by...
Acute exposure to high-dose gamma radiation due to radiological disasters or cancer radiotherapy can result in radiation-induced lung injury (RILI), characterized by acute pneumonitis and subsequent lung fibrosis. A microfluidic organ-on-a-chip lined by human lung alveolar epithelium interfaced with pulmonary endothelium (Lung Alveolus Chip) is used to model acute RILI in vitro. Both lung epithelium and endothelium exhibit DNA damage, cellular hypertrophy, upregulation of inflammatory cytokines, and loss of barrier function within 6 h of radiation exposure, although greater damage is observed in the endothelium. The radiation dose sensitivity observed on-chip is more like the human lung than animal preclinical models. The Alveolus Chip is also used to evaluate the potential ability of two drugs - lovastatin and prednisolone - to suppress the effects of acute RILI. These data demonstrate that the Lung Alveolus Chip provides a human relevant alternative for studying the molecular basis of acute RILI and may be useful for evaluation of new radiation countermeasure therapeutics.
Topics: Animals; Humans; Lung Injury; Lung; Radiation Injuries; Acute Lung Injury; Gamma Rays; Lab-On-A-Chip Devices
PubMed: 37845224
DOI: 10.1038/s41467-023-42171-z -
International Journal of Oral and... Jan 2024Clinicians frequently prescribe systemic antibiotics after lower third molar extractions to prevent complications such as surgical site infections and dry socket. A... (Meta-Analysis)
Meta-Analysis Review
Clinicians frequently prescribe systemic antibiotics after lower third molar extractions to prevent complications such as surgical site infections and dry socket. A systematic review of randomised clinical trials was conducted to compare the risk of dry socket and surgical site infection after the removal of lower third molars with different prophylactic antibiotics. The occurrence of any antibiotic-related adverse event was also analysed. A pairwise and network meta-analysis was performed to establish direct and indirect comparisons of each outcome variable. Sixteen articles involving 2158 patients (2428 lower third molars) were included, and the following antibiotics were analysed: amoxicillin (with and without clavulanic acid), metronidazole, azithromycin, and clindamycin. Pooled results favoured the use of antibiotics to reduce dry socket and surgical site infection after the removal of a lower third molar, with a number needed to treat of 25 and 18, respectively. Although antibiotic prophylaxis was found to significantly reduce the risk of dry socket and surgical site infection in patients undergoing lower third molar extraction, the number of patients needed to treat was high. Thus, clinicians should evaluate the need to prescribe antibiotics taking into consideration the patient's systemic status and the individual risk of developing a postoperative infection.
Topics: Humans; Dry Socket; Antibiotic Prophylaxis; Surgical Wound Infection; Molar, Third; Network Meta-Analysis; Anti-Bacterial Agents; Tooth Extraction
PubMed: 37612199
DOI: 10.1016/j.ijom.2023.08.001