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Periodontology 2000 Oct 2023Oral rehabilitation through implant supported dental restorations often requires a ridge augmentation procedure (RAP) prior to implant fixture placement since tooth... (Review)
Review
Oral rehabilitation through implant supported dental restorations often requires a ridge augmentation procedure (RAP) prior to implant fixture placement since tooth extraction/loss results in alveolar ridge deficiencies. Although RAP-related surgical techniques and biomaterials have been in practice for several decades, outcomes are not always predictable. Post-surgical complications experienced during the early or late wound healing phases may jeopardize the targeted ideal ridge dimensions, required for implant fixture placement, and may have other consequences, such as negatively impacting the patient's quality of life. This review describes reported post-surgical complications following RAP under the following subtitles: complications by tissue type, complications in function and aesthetics, complications by healing time, complications by biomaterial type, and complications by surgical protocol modalities. Specifically, RAP performed by using particulate bone graft substitutes and related complications are explored. Modalities developed to prevent/manage these complications are also discussed.
Topics: Humans; Alveolar Ridge Augmentation; Dental Implantation, Endosseous; Quality of Life; Bone Transplantation; Alveolar Process; Bone Substitutes; Biocompatible Materials; Tooth Extraction; Tooth Socket; Dental Implants
PubMed: 37489632
DOI: 10.1111/prd.12509 -
Physiological Reviews Apr 2024Lung endothelia in the arteries, capillaries, and veins are heterogeneous in structure and function. Lung capillaries in particular represent a unique vascular niche,... (Review)
Review
Lung endothelia in the arteries, capillaries, and veins are heterogeneous in structure and function. Lung capillaries in particular represent a unique vascular niche, with a thin yet highly restrictive alveolar-capillary barrier that optimizes gas exchange. Capillary endothelium surveys the blood while simultaneously interpreting cues initiated within the alveolus and communicated via immediately adjacent type I and type II epithelial cells, fibroblasts, and pericytes. This cell-cell communication is necessary to coordinate the immune response to lower respiratory tract infection. Recent discoveries identify an important role for the microtubule-associated protein tau that is expressed in lung capillary endothelia in the host-pathogen interaction. This endothelial tau stabilizes microtubules necessary for barrier integrity, yet infection drives production of cytotoxic tau variants that are released into the airways and circulation, where they contribute to end-organ dysfunction. Similarly, beta-amyloid is produced during infection. Beta-amyloid has antimicrobial activity, but during infection it can acquire cytotoxic activity that is deleterious to the host. The production and function of these cytotoxic tau and amyloid variants are the subject of this review. Lung-derived cytotoxic tau and amyloid variants are a recently discovered mechanism of end-organ dysfunction, including neurocognitive dysfunction, during and in the aftermath of infection.
Topics: Humans; Multiple Organ Failure; Lung; Endothelium, Vascular; Amyloid; Amyloid beta-Peptides
PubMed: 37561137
DOI: 10.1152/physrev.00006.2023 -
Periodontology 2000 Oct 2023In the last 20 years, immediate implant placement has been proposed as a predictable protocol to replace failing teeth. The research conducted in preclinical and... (Review)
Review
In the last 20 years, immediate implant placement has been proposed as a predictable protocol to replace failing teeth. The research conducted in preclinical and clinical studies have focused on soft and hard tissue changes following tooth extraction and immediate implant placement. Different approaches for hard and soft tissue grafting together with provisional restorations have been proposed to compensate tissue alterations. This review analyzed some relevant clinical and preclinical literature focusing on the impact of bone grafting procedures on immediate implant placement in terms of hard and soft tissue changes, aesthetic results, and patient-related outcomes.
Topics: Humans; Immediate Dental Implant Loading; Bone Transplantation; Tooth Socket; Dental Implantation, Endosseous; Dental Implants, Single-Tooth; Tooth Extraction; Esthetics, Dental; Treatment Outcome
PubMed: 37658586
DOI: 10.1111/prd.12516 -
Current Topics in Developmental Biology 2024The mammalian lung completes its last step of development, alveologenesis, to generate sufficient surface area for gas exchange. In this process, multiple cell types... (Review)
Review
The mammalian lung completes its last step of development, alveologenesis, to generate sufficient surface area for gas exchange. In this process, multiple cell types that include alveolar epithelial cells, endothelial cells, and fibroblasts undergo coordinated cell proliferation, cell migration and/or contraction, cell shape changes, and cell-cell and cell-matrix interactions to produce the gas exchange unit: the alveolus. Full functioning of alveoli also involves immune cells and the lymphatic and autonomic nervous system. With the advent of lineage tracing, conditional gene inactivation, transcriptome analysis, live imaging, and lung organoids, our molecular understanding of alveologenesis has advanced significantly. In this review, we summarize the current knowledge of the constituents of the alveolus and the molecular pathways that control alveolar formation. We also discuss how insight into alveolar formation may inform us of alveolar repair/regeneration mechanisms following lung injury and the pathogenic processes that lead to loss of alveoli or tissue fibrosis.
Topics: Animals; Humans; Pulmonary Alveoli; Pulmonary Gas Exchange; Regeneration; Lung; Lung Injury
PubMed: 38729684
DOI: 10.1016/bs.ctdb.2024.01.002 -
Clinical Oral Investigations Aug 2023The aim of the present randomized controlled trial (RCT) was to evaluate the efficacy of different alveolar ridge preservation (ARP) techniques on dimensional... (Randomized Controlled Trial)
Randomized Controlled Trial
OBJECTIVE
The aim of the present randomized controlled trial (RCT) was to evaluate the efficacy of different alveolar ridge preservation (ARP) techniques on dimensional alterations after tooth extraction, based on clinical measurements.
BACKGROUND
Alveolar ridge preservation (ARP) is a common procedure in every day clinical practice, when dental implants are involved in treatment planning. In ARP procedures, a bone grafting material is combined with a socket sealing (SS) material in order to compensate the alveolar ridge dimensional alterations after tooth extraction. Xenograft and allograft are the most frequently used bone grafts in ARP, while free gingival graft (FGG), collagen membrane, and collagen sponge (CS) usually applied as SS materials. The evidence comparing xenograft and allograft directly in ARP procedure is scarce. In addition, FGG is usually combined with xenograft as SS material, while the evidence combing allograft with FGG is absent. Moreover, CS could probably be an alternative choice in ARP as SS material, since it has been used in previous studies but more clinical trials are required to evaluate its effectiveness.
MATERIALS AND METHODS
Forty-one patients were randomly assigned in four treatment groups: (A) freeze-dried bone allograft (FDBA) covered with collagen sponge (CS), (B) FDBA covered with free gingival graft (FGG), (C) demineralized bovine bone mineral xenograft (DBBM) covered with FGG, and (D) FGG alone. Clinical measurements were performed immediately after tooth extraction and 4 months later. The related outcomes pertained to both vertical and horizontal assessment of bone loss.
RESULTS
Overall, groups A, B, and C presented significantly less vertical and horizontal bone resorption compared to group D. No statistically significant difference was observed between allograft and xenograft, except for the vertical bone resorption at the buccal central site, where xenograft showed marginally statistically significantly reduced bone loss compared to allograft (group C vs group B: adjusted β coef: 1.07 mm; 95%CI: 0.01, 2.10; p = 0.05). No significant differences were observed in hard tissue dimensions when CS and FGG were applied over FDBA.
CONCLUSIONS
No differences between FDBA and DBBM could practically be confirmed. In addition, CS and FGG were equally effective socket sealing materials when combined with FDBA, regarding bone resorption. More RCTs are needed to compare the histological differences between FDBA and DBBM and the effect of CS and FGG on soft tissue dimensional changes.
CLINICAL RELEVANCE
Xenograft and allograft were equally efficient in ARP 4 months after tooth extraction in horizontal level. Xenograft maintained the mid-buccal site of the socket marginally better than the allograft, in vertical level. FGG and CS were equally efficient as SS materials regarding the hard tissue dimensional alterations.
TRIAL REGISTRATION
Clinical trial registration Number: NCT04934813 (clinicaltrials.gov).
Topics: Humans; Animals; Cattle; Tooth Socket; Alveolar Process; Alveolar Bone Loss; Collagen; Tooth Extraction; Alveolar Ridge Augmentation
PubMed: 37227497
DOI: 10.1007/s00784-023-05068-1 -
Journal of Dental Research Mar 2024Periodontal mesenchymal stem cells (MSCs) play a crucial role in maintaining periodontium homeostasis and in tissue repair. However, little is known about how...
Periodontal mesenchymal stem cells (MSCs) play a crucial role in maintaining periodontium homeostasis and in tissue repair. However, little is known about how periodontal MSCs in vivo respond under periodontal disease conditions, posing a challenge for periodontium tissue regeneration. In this study, Gli1 was used as a periodontal MSC marker and combined with a Gli1-cre ERT2 mouse model for lineage tracing to investigate periodontal MSC fate in an induced periodontitis model. Our findings show significant changes in the number and contribution of Gli1 MSCs within the inflamed periodontium. The number of Gli1 MSCs that contributed to periodontal ligament homeostasis decreased in the periodontitis-induced teeth. While the proliferation of Gli1 MSCs had no significant difference between the periodontitis and the control groups, more Gli1 MSCs underwent apoptosis in diseased teeth. In addition, the number of Gli1 MSCs for osteogenic differentiation decreased during the progression of periodontitis. Following tooth extraction, the contribution of Gli1 MSCs to the tooth socket repair was significantly reduced in the periodontitis-induced teeth. Collectively, these findings indicate that the function of Gli1 MSCs in periodontitis was compromised, including reduced contribution to periodontium homeostasis and impaired injury response.
Topics: Mice; Animals; Zinc Finger Protein GLI1; Osteogenesis; Periodontitis; Periodontium; Mesenchymal Stem Cells; Periodontal Ligament
PubMed: 38284236
DOI: 10.1177/00220345231220915 -
Microbiome Oct 2023Mammalian mucosal barriers secrete antimicrobial peptides (AMPs) as critical, host-derived regulators of the microbiota. However, mechanisms that support microbiota...
BACKGROUND
Mammalian mucosal barriers secrete antimicrobial peptides (AMPs) as critical, host-derived regulators of the microbiota. However, mechanisms that support microbiota homeostasis in response to inflammatory stimuli, such as supraphysiologic oxygen, remain unclear.
RESULTS
We show that supraphysiologic oxygen exposure to neonatal mice, or direct exposure of intestinal organoids to supraphysiologic oxygen, suppresses the intestinal expression of AMPs and alters intestinal microbiota composition. Oral supplementation of the prototypical AMP lysozyme to hyperoxia-exposed neonatal mice reduced hyperoxia-induced alterations in their microbiota and was associated with decreased lung injury.
CONCLUSIONS
Our results identify a gut-lung axis driven by intestinal AMP expression and mediated by the intestinal microbiota that is linked to lung injury in newborns. Together, these data support that intestinal AMPs modulate lung injury and repair. Video Abstract.
Topics: Animals; Mice; Gastrointestinal Microbiome; Lung Injury; Antimicrobial Peptides; Hyperoxia; Lung; Oxygen; Mammals
PubMed: 37845716
DOI: 10.1186/s40168-023-01673-0 -
The Journal of Dairy Research Nov 2023The milk fat globule membrane (MFGM) is formed by complex cell biological processes in the lactating mammary epithelial cell which result in the release of the milk fat... (Review)
Review
The milk fat globule membrane (MFGM) is formed by complex cell biological processes in the lactating mammary epithelial cell which result in the release of the milk fat globule (MFG) into the secretory alveolus. The MFG is bounded by a continuous unit membrane (UM), separated from the MFG lipid by a thin layer of cytoplasm. This unique apocrine secretion process has been shown in all of the mammary species so far investigated. Once the MFG is released into the alveolus there is a considerable transformation of the UM with its attached cytoplasm. This is the MFGM. The transformation is stable and expressed milk shows the same transformed MFGM structure. Again, this transformation of structure is common to all mammalian species so far investigated. However, the explanation of the transformation very much depends on the method of investigation. Transmission electron microscope (TEM) studies suggest a literal breakdown to a discontinuous UM plus cytoplasm in patches and strands, whereas more recent confocal laser scanning light microscopy (CLSM) studies indicate a separation, in a continuous UM, of two phases, one liquid ordered and the other liquid disordered. This review is designed to show that the TEM and CLSM results show different views of the same structures once certain deficiencies in techniques are factored in.
Topics: Female; Animals; Lactation; Milk Proteins; Glycolipids; Glycoproteins; Mammals; Lipid Droplets
PubMed: 38226400
DOI: 10.1017/S0022029923000742