Addition of Resolvins D1 or E1 to Collagen Membranes Mitigates Their Resorption in Diabetic Rats.

Uncontrolled diabetes is characterized by aberrant inflammatory reactions and increased collagenolysis. We have reported that it accelerates the degradation of implanted collagen membranes (CM), thus compromising their function in regenerative procedures. In recent years, a group of physiological anti-inflammatory agents called specialized pro-resolving lipid mediators (SPMs) have been tested as a treatment for various inflammatory conditions, either systemically or locally, via medical devices.

Single-cell transcriptomic analysis of oral masticatory and lining mucosa-derived mesenchymal stromal cells.

Aim: To reveal the heterogeneity of ex vivo-cultured human mesenchymal stromal cells derived from either masticatory or lining oral mucosa.

Materials And Methods: Cells were retrieved from the lamina propria of the hard palate and alveolar mucosa of three individuals. The analysis of transcriptomic-level differences was accomplished using single-cell RNA sequencing.

Cross-linked hyaluronic acid slows down collagen membrane resorption in diabetic rats through reducing the number of macrophages.

Objectives: We previously showed that accelerated degradation of collagen membranes (CMs) in diabetic rats is associated with increased infiltration of macrophages and blood vessels. Since pre-implantation immersion of CMs in cross-linked high molecular weight hyaluronic acid (CLHA) delays membrane degradation, we evaluated here its effect on the number of macrophages and endothelial cells (ECs) within the CM as a possible mechanism for inhibition of CM resorption.

Materials And Methods: Diabetes was induced with streptozotocin in 16 rats, while 16 healthy rats served as control.

Porphyromonas gingivalis lipopolysaccharide and glycated serum albumin increase the production of several pro-inflammatory molecules in human gingival fibroblasts via NFκB.

Objective: Diabetes increases the incidence/severity of periodontal diseases by inducing a chronic inflammation, driven by accumulation of AGEs (advanced glycation end products). We tested whether glycated human serum albumin (G-HSA, a form of AGE), representing a diabetic state, augments the pro-inflammatory response of human gingival fibroblasts (hGFs) to a bacterial challenge (Porphyromonas gingivalis Lipopolysaccharide (LPS)).

Methods: Primary hGFs were incubated with LPS (0.

Accelerated degradation of collagen membranes in type 1 diabetic rats is associated with increased expression and production of several inflammatory molecules.

Background: Membrane durability is critical for regenerative procedures. We reported previously that type 1-like diabetes in rats accelerates the degradation of collagen membranes and we tested here whether this is associated with increased local production of inflammatory molecules as part of a diabetes-induced chronic inflammation around and within the membranes.

Methods: Collagen membrane discs were implanted under the scalp in diabetic (streptozotocin-induced) and control rats, which were sacrificed after 2 or 3 weeks.

Hyaluronic acid slows down collagen membrane degradation in uncontrolled diabetic rats.

Aim: To examine the in vitro biokinetics of hyaluronic acid (HA) from a collagen membrane (CM) and to evaluate the in vivo effect of immersion of the CM in HA solution on its degradation in streptozotocin (STZ)-induced diabetes conditions in a rat calvaria subcutaneous model.

Background: CM degradation is accelerated in uncontrolled diabetic rats. Immersion of CM in HA has been suggested to decrease their resorption rate without interfering with their tissue integration and structural degradation.

Soft and Hard Tissue Regeneration-A Special Issue of Dentistry Journal.

This Special Issue entitled "Soft and Hard Tissue Regeneration" will cover both periodontal and implant therapies.[..

Differences in crestal bone-to-implant contact following an under-drilling compared to an over-drilling protocol. A study in the rabbit tibia.

Objectives: The objective of this study is to compare bone-to-implant contact (BIC) between implants inserted at high torque due to under-drilling of the crestal bone to those inserted at low torque due to over-drilling of the crestal bone.

Materials And Methods: Forty implants with diameters of 3.75 mm (group A) or 3.

Enamel Matrix Derivative Promotes Healing of a Surgical Wound in the Rat Oral Mucosa.

Background: Enamel matrix proteins (EMPs) play a role in enamel formation and the development of the periodontium. Sporadic clinical observations of periodontal regeneration treatments with enamel matrix derivative (EMD), a commercial formulation of EMPs, suggest that it also promotes post-surgical healing of soft tissues. In vitro studies showed that EMD stimulates various cellular effects, which could potentially enhance wound healing.

Accelerated degradation of collagen membranes in diabetic rats is associated with increased infiltration of macrophages and blood vessels.

Objectives: Increased collagenolytic activity in diabetes may compromise collagen membrane (CM) survival. Tetracycline (TTC) possesses anti-collagenolytic properties and delays CM degradation. This study evaluated macrophage and capillary infiltration within CMs in diabetic rats.

Tetracycline impregnation affects degradation of porcine collagen matrix in healthy and diabetic rats.

Objectives: The present study evaluated the degradation of collagen matrix (CM) immersed in tetracycline (TTC) or phosphate-buffered saline (PBS) in diabetic and normoglycemic rats.

Materials And Methods: Diabetes was induced in 15 rats by systemic streptozotocin (STZ) (experimental); 15 healthy rats served as controls. One day before implantation 60 CM disks, 5 mm in diameter, were labeled with biotin: 30 were immersed in tetracycline (TTC) and 30 in PBS.

In vitro models for evaluation of periodontal wound healing/regeneration.

Periodontal wound healing and regeneration are highly complex processes, involving cells, matrices, molecules and genes that must be properly choreographed and orchestrated. As we attempt to understand and influence these clinical entities, we need experimental models to mimic the various aspects of human wound healing and regeneration. In vivo animal models that simulate clinical situations of humans can be costly and cumbersome.

Evaluation of a topical herbal patch for soft tissue wound healing: an animal study.

Aim: This study evaluated the effects of a topical herbal patch (PerioPatch®) for gingival wound healing in a rat model.

Materials And Methods: A mid-crestal incision was performed on each side of the edentulous anterior maxilla in 48, 6-month-old, Wistar rats. Full-thickness flaps were raised, repositioned and sutured.

AGEs induce caspase-mediated apoptosis of rat BMSCs via TNFα production and oxidative stress.

Diabetic humans and animals exhibit lower bone mass and healing, resulting from diminished bone formation. We have recently reported that type 1 diabetic rats have fewer bone marrow osteoprogenitor cells, and since the formation of advanced glycation end products (AGEs) in bone increases in diabetes, we explored possible mechanisms involved in AGE-induced apoptosis of rat bone marrow stromal cells (BMSCs). BMSCs isolated from 4-month-old rats were exposed to 10-400 μg/ml AGE-BSA for 16 h and apoptosis was quantified with PI/annexin V staining and flow cytometry.

Bone progenitors produced by direct osteogenic differentiation of the unprocessed bone marrow demonstrate high osteogenic potential in vitro and in vivo.

Tissue-engineered bone grafts seeded with mesenchymal stem cells (MSCs) have been sought as a replacement for bone grafts currently used for bone repair. For production of osteogenic constructs, MSCs are isolated from bone marrow (BM) or other tissues, expanded in culture, then trypsinized, and seeded on a scaffold. Predifferentiation of seeded cells is often desired.

Opposing effects of diabetes and tetracycline on the degradation of collagen membranes in rats.

Background: Increased collagenolytic activity, characteristic of uncontrolled diabetes, may compromise collagen membrane (CM) survival. Tetracycline (TCN) possesses anticollagenolytic properties and delays CM degradation in healthy animals. This study evaluates the degradation of TCN--immersed and -non-immersed CMs in rats with diabetes compared to those with normoglycemia.

Clinical and histomorphometric observations around dual acid-etched and calcium phosphate nanometer deposited-surface implants.

Purpose: The objective of this study was to compare the clinical and histologic peri-implant parameters of a nano-calcium phosphate (CaP)-coated dual acid-etched (DAE) implant (n = 7) to those of an uncoated DAE implant (n = 7).

Materials And Methods: The study included seven dogs who received implants bilaterally in edentulous mandibular areas; in the right side, procedures were performed 8 months after procedures in the left mandible. Clinical parameters were measured prior to euthanasia (8 months after the second set of implants was placed), followed by histologic nondecalcified processing for morphometric evaluation.

The effect of surface treatments on the adhesion of electrochemically deposited hydroxyapatite coating to titanium and on its interaction with cells and bacteria.

The effect of different mechanical and chemical pre-treatments on the adhesion strength of hydroxyapatite (HAp) coating on a commercially pure titanium (CP-Ti) substrate was studied by means of a standard tensile test followed by microscopic and chemical analysis to determine the locus of fracture. In addition, the effects of either these pre-treatments or post-treatment by low-energy electron irradiation, which allowed tuning the wettability of the surface, on both osteoblast progenitor attachment and S. aureus bacteria attachment were investigated.

Simultaneous versus two-stage implant placement and guided bone regeneration in the canine: histomorphometry at 8 and 16 months.

Aim: To compare the effect of timing of implant placement and guided bone regeneration (GBR) procedure on osseointegration and newly formed bone at 8 and 16 months.

Material And Methods: In seven dogs, four different sites were bilaterally established: (1) an implant placed in a 6-month healed (6m-GBR) bovine bone mineral (BBM) grafted site; (2) a simultaneously placed implant with the grafted BBM (Si-GBR) followed by a membrane coverage; (3) an implant placed in a membrane-protected non-grafted defect; and (4) an implant placement in a naturally healed site (Cont). Histomorphometry was obtained at 8 and 16 months post-implant placement.

Bio-degradation of a resorbable collagen membrane (Bio-Gide) applied in a double-layer technique in rats.

Objective: The aim of this study was to evaluate histologically the bio-degradation of two layers of Bio-Gide((R)) (BG) membrane, as compared with that of a single layer.

Material And Methods: Two circular calvarial bony defects, 5 mm in diameter, were made in 24 Wistar rats. BG membrane, labeled with biotin, was cut into 5-mm-diameter disks, and placed in defects either as a mono-layer membrane (MLM) or as a double-layer membrane (DLM).

Prostaglandin E2 inhibits the proliferation of human gingival fibroblasts via the EP2 receptor and Epac.

Elevated levels of prostaglandins such as PGE(2) in inflamed gingiva play a significant role in the tissue destruction caused by periodontitis, partly by targeting local fibroblasts. Only very few studies have shown that PGE(2) inhibits the proliferation of a gingival fibroblast (GF) cell line, and we expanded this research by using primary human GFs (hGFs) and looking into the mechanisms of the PGE(2) effect. GFs derived from healthy human gingiva were treated with PGE(2) and proliferation was assessed by measuring cell number and DNA synthesis and potential signaling pathways were investigated using selective activators or inhibitors.

Effect of systemic tetracycline on the degradation of tetracycline-impregnated bilayered collagen membranes: an animal study.

Background: Premature collagen membrane degradation may compromise the outcome of osseous regenerative procedures. Tetracyclines (TTCs) inhibit the catalytic activities of human metalloproteinases. Preprocedural immersion of collagen membranes in TTC and systemic administration of TTC may be possible alternatives to reduce the biodegradation of native collagen membranes.

Histomorphometric evaluation of natural mineral combined with a synthetic cell-binding peptide (P-15) in critical-size defects in the rat calvaria.

Purpose: The objective of this study was to histomorphometrically evaluate the synthetic peptide analog P-15 bound to anorganic bovine mineral (Pepgen/P15) in critical-size defects in the rat calvaria.

Materials And Methods: A 5-mm-diameter critical-size defect was prepared in 48 rat skulls and divided into 4 equal groups: Pepgen/P15 particles covered by a membrane, Pepgen/P15 particles uncovered, nongrafted membrane-protected sites, and nongrafted uncovered control sites. At 12 weeks, histomorphometric measurements were made of the percentage area of newly formed bone and residual particles, the length of internal and external bone bridging, and linearly, the regenerated marginal and central total tissue augmentation height.

Systemic tetracycline delays degradation of three different collagen membranes in rat calvaria.

Objectives: The aim of this study was to quantitatively evaluate the effect of systemic tetracycline (TTC) on the degradation of three different collagen membranes.

Materials And Methods: Collagen membranes were cut into 5 mm diameter membrane discs and labeled with aminohexanoyl-biotin-N-hydroxy-succinimide ester. One membrane disc each of a non-cross-linked [BioGide (BG)], glutaraldehyde cross-linked [BioMend Extend (BM)], and ribose cross-linked [Ossix (OS)] was implanted on the calvaria of 40 Wistar rats.