Correction of Peri-Implant Soft Tissue Fenestration With Bony Dehiscence Associated With Intrabony Defect: A 2-Year Case Report.

Soft and hard tissue deficiencies around dental implants which can potentially compromise implant survival are commonly encountered. Complicated interventions are often required to address and resolve combinations of soft and hard tissue defects. This case report describes the management of peri-implant soft tissue fenestration accompanied by bony dehiscence associated with intrabony defect through soft tissue modification. A 51-year-old female was referred to the Periodontics and Oral Medicine Clinic with labial soft tissue fenestration at the maxillary left canine implant-supported crown. The patient complained of discomfort and malodor at the implant site. The implant showed mucosal fenestration and 6 mm probing depth (PD) with profuse bleeding at the distolabial site without mobility. A cone beam computed tomography (CBCT) demonstrated labial bony dehiscence associated with a 5.56-mm intrabony defect at mesial and distal surfaces. The implant was diagnosed as peri-implantitis with soft tissue deficiency. The treatment comprised oral hygiene instruction, debridement of the implant and all natural teeth, and mucogingival surgery with free connective tissue graft by the envelope technique. Two weeks after debridement, the mucosal margin of the implant disappeared, presenting soft tissue dehiscence of 4 × 4 mm. Mucogingival surgery was performed 3 weeks later. A 2-year follow-up revealed a stable mucosal margin with PD ranged 2-4 mm. In conclusion, modification of the soft tissue thickness around the implant together with excellent plaque control by the patient successfully maintained peri-implant health.

Effect of Periodontal Ligament Stem Cells-Derived Conditioned Medium on Gene Expression and Differentiation of Tumor Necrosis Factor-α-Challenged Osteoblasts.

OBJECTIVES: Tumor necrosis factor-α (TNF-α) causes bone resorption in periodontitis. It induces the production of receptor activator of NF-κB ligand (RANKL) from osteoblasts, leading to the disturbance of bone homeostasis through RANKL, RANK, and osteoprotegerin (OPG) axis. This study aimed to explore the effect of periodontal ligament stem cells-derived conditioned medium (PDLSCs-CM) on gene expression related to bone homeostasis and the differentiation of TNF-α-challenged osteoblasts. MATERIALS AND METHODS: Human osteoblasts were cultured with 50 ng/mL of TNF-α and 0, 1, 10, and 100 µg/ mL of PDLSCs-CM. Osteoblasts cultured without TNF-α and PDLSCs-CM were served as control. Gene expression of RANKL, OPG, and interleukin-1ß (IL-1ß) was evaluated by reverse transcription quantitative polymerase chain reaction at 48 hours. The early-stage and late-stage differentiation of TNF-α-challenged osteoblasts without or with PDLSCs-CM was explored by alkaline phosphatase (ALP) activity and alizarin red staining, respectively, at day 1, 3, 6, 9, and 12. STATISTICAL ANALYSIS: Mann-Whitney U test was used to analyze the differences in gene expression of TNF-α-challenged osteoblasts at 24 and 48 hours, and Kruskal-Wallis test was used to analyze the effect of PDLSCs-CM on gene expression and ALP activity among all experimental groups using SPSS software version 21.0. Statistical significance was considered with p-value less than 0.05. RESULTS: Expression of RANKL, OPG and IL-1ß was significantly upregulated in TNF-α-challenged osteoblasts compared to the untreated control. The PDLSCs-CM at 1 and 10 µg/mL downregulated gene expression of TNF-α-challenged osteoblasts compared to the group without PDLSCs-CM, but the difference did not reach statistical significance. The ALP activity was decreased in TNF-α-challenged osteoblasts. The addition of PDLSCs-CM did not alter ALP activity of TNF-α-challenged osteoblasts. Alizarin red staining was comparable in the TNF-α-challenged osteoblasts cultured without or with PDLSCs-CM. CONCLUSIONS: The PDLSCs-CM did not alter gene expression involved in bone homeostasis and differentiation of TNF-α-challenged osteoblasts.

Stem cell-derived exosomes from human exfoliated deciduous teeth promote angiogenesis in hyperglycemic-induced human umbilical vein endothelial cells.

OBJECTIVE: To investigate the angiogenesis in human umbilical vein endothelial cells (HUVEC) under high glucose concentration, treated with exosomes derived from stem cells from human exfoliated deciduous teeth (SHED). METHODOLOGY: SHED-derived exosomes were isolated by differential centrifugation and were characterized by nanoparticle tracking analysis, transmission electron microscopy, and flow cytometric assays. We conducted in vitro experiments to examine the angiogenesis in HUVEC under high glucose concentration. Cell Counting Kit-8, migration assay, tube formation assay, quantitative real-time PCR, and immunostaining were performed to study the role of SHED-derived exosomes in cell proliferation, migration, and angiogenic activities. RESULTS: The characterization confirmed SHED-derived exosomes: size ranged from 60-150 nm with a mode of 134 nm, cup-shaped morphology, and stained positively for CD9, CD63, and CD81. SHED-exosome significantly enhanced the proliferation and migration of high glucose-treated HUVEC. A significant reduction was observed in tube formation and a weak CD31 staining compared to the untreated-hyperglycemic-induced group. Interestingly, exosome treatment improved tube formation qualitatively and demonstrated a significant increase in tube formation in the covered area, total branching points, total tube length, and total loop parameters. Moreover, SHED-exosome upregulates angiogenesis-related factors, including the GATA2 gene and CD31 protein. CONCLUSIONS: Our data suggest that the use of SHED-derived exosomes potentially increases angiogenesis in HUVEC under hyperglycemic conditions, which includes increased cell proliferation, migration, tubular structures formation, GATA2 gene, and CD31 protein expression. SHED-exosome usage may provide a new treatment strategy for periodontal patients with diabetes mellitus.

Effect of Nicotine and Porphyromonas gingivalis on the Differentiation Properties of Periodontal Ligament Fibroblasts.

OBJECTIVES: This study aimed to evaluate the effect of Porphyromonas gingivalis and nicotine on the in vitro osteogenic differentiation of periodontal ligament (PDL) fibroblasts. MATERIALS AND METHODS: PDLs were cultured in Dulbecco's modified Eagle's medium containing 10% fetal bovine serum at 37°C under 5% CO2 and 100% humidified atmosphere. Cells were incubated with various concentrations of nicotine and P. gingivalis extracts, and cell viability was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay. To study cell differentiation, PDLs (5 × 104cells) were treated with the osteogenic differentiation medium containing 10 mM ß-glycerophosphate, 10 nM dexamethasone, 50 mg/mL ascorbic acid, 1 µM nicotine, and 50 µg/mL P. gingivalis lysate. mRNA samples were collected at 0, 7, and 14 days. Odontogenic-related gene expression, namely, Runt-related transcription factor 2 (Runx2), collagen type I (COL1A1), and alkaline phosphatase (ALP) was determined by reverse transcription quantitative polymerase chain reaction (RT-qPCR). Calcified nodule formation was determined on day 28 using Alizarin Red S. Analysis of variance and Tukey's test were used to compare the difference among groups at significant level of p < 0.05. RESULTS: It showed that 50 µg/mL of P. gingivalis lysate and 1 µM of nicotine showed no toxicity to PDLs. Runx2, COL1A1, and ALP expression were found to decrease significantly after 7 days of treatment, while osteocalcin expression was found to decrease after 14 days. The nodule formation in the control group was much greater in both number and size of nodules than in experimental groups, which implied a positive sign of calcium deposition in controls. CONCLUSION: The results indicated that nicotine and P. gingivalis showed adverse effect on osteogenic differentiation properties of PDLs.

Stem cell-derived exosomes from human exfoliated deciduous teeth promote angiogenesis in hyperglycemic-induced human umbilical vein endothelial cells

Abstract Objective To investigate the angiogenesis in human umbilical vein endothelial cells (HUVEC) under high glucose concentration, treated with exosomes derived from stem cells from human exfoliated deciduous teeth (SHED). Methodology SHED-derived exosomes were isolated by differential centrifugation and were characterized by nanoparticle tracking analysis, transmission electron microscopy, and flow cytometric assays. We conducted in vitro experiments to examine the angiogenesis in HUVEC under high glucose concentration. Cell Counting Kit-8, migration assay, tube formation assay, quantitative real-time PCR, and immunostaining were performed to study the role of SHED-derived exosomes in cell proliferation, migration, and angiogenic activities. Results The characterization confirmed SHED-derived exosomes: size ranged from 60-150 nm with a mode of 134 nm, cup-shaped morphology, and stained positively for CD9, CD63, and CD81. SHED-exosome significantly enhanced the proliferation and migration of high glucose-treated HUVEC. A significant reduction was observed in tube formation and a weak CD31 staining compared to the untreated-hyperglycemic-induced group. Interestingly, exosome treatment improved tube formation qualitatively and demonstrated a significant increase in tube formation in the covered area, total branching points, total tube length, and total loop parameters. Moreover, SHED-exosome upregulates angiogenesis-related factors, including the GATA2 gene and CD31 protein. Conclusions Our data suggest that the use of SHED-derived exosomes potentially increases angiogenesis in HUVEC under hyperglycemic conditions, which includes increased cell proliferation, migration, tubular structures formation, GATA2 gene, and CD31 protein expression. SHED-exosome usage may provide a new treatment strategy for periodontal patients with diabetes mellitus.