Volumetric evaluation of effects of platelet-rich fibrin and concentrated growth factor on early bone healing after endodontic microsurgery: a randomized controlled trial.

BACKGROUND: This randomized controlled clinical trial compared the effects of platelet-rich fibrin (PRF) and concentrated growth factor (CGF) on early bone healing after endodontic microsurgery. METHODS: Eighteen patients with an isolated periapical lesion < 10 mm in the maxillary anterior region were randomly assigned to three groups: control, PRF, or CGF. Endodontic microsurgery was performed and PRF or CGF membranes were placed over the bone defects in the experimental groups. The volume of the bone defect at postoperative one week, three months, and six months was evaluated using cone-beam computed tomography and Mimics software. The results were statistically analyzed using the Kruskal-Wallis test and post-hoc Mann-Whitney U test with Bonferroni correction. RESULTS: At the three-month follow-up, the PRF and CGF groups showed significantly greater bone healing compared with the control group (p > 0.05). However, no significant difference was observed between the PRF and CGF groups. At the six-month follow-up, no significant differences were observed between the groups. CONCLUSIONS: These results suggested that PRF and CGF promote early bone healing after endodontic microsurgery.

Technical Note on Simplified Free Gingival Graft Using Tack Fixation (sFGG).

Free gingival graft (FGG) is the gold standard procedure for the reliable augmentation of lost keratinized mucosa (KM) around dental implants. This conventional surgical approach has its drawbacks, including limitations in manipulation, the requirement for suturing, postoperative discomfort, and pain. This case report aimed to evaluate the efficacy of a simplified free gingival graft (sFGG) in addressing the issue of inadequate keratinized mucosa around dental implants. Fixation tacks were used to perform the sFGG procedure. Initially, a partial-thickness flap was created and apically repositioned. The gingival graft was harvested from the palate with a narrow profile and securely affixed to the recipient site using 5 mm long fixation tacks. Significant gains in keratinized mucosa were achieved and successfully maintained within 1 year. Consequently, the sFGG technique emerges as a simple and reliable treatment approach for managing inadequate keratinized mucosa around dental implants.

GPR183 Regulates 7α,25-Dihydroxycholesterol-Induced Oxiapoptophagy in L929 Mouse Fibroblast Cell.

7α,25-dihydroxycholesterol (7α,25-DHC) is an oxysterol synthesized from 25-hydroxycholesterol by cytochrome P450 family 7 subfamily B member 1 (CYP7B1) and is a monooxygenase (oxysterol-7α-hydroxylase) expressed under inflammatory conditions in various cell types. In this study, we verified that 7α,25-DHC-induced oxiapoptophagy is mediated by apoptosis, oxidative stress, and autophagy in L929 mouse fibroblasts. MTT assays and live/dead cell staining revealed that cytotoxicity was increased by 7α,25-DHC in L929 cells. Consequentially, cells with condensed chromatin and altered morphology were enhanced in L929 cells incubated with 7α,25-DHC for 48 h. Furthermore, apoptotic population was increased by 7α,25-DHC exposure through the cascade activation of caspase-9, caspase-3, and poly (ADP-ribose) polymerase in the intrinsic pathway of apoptosis in these cells. 7α,25-DHC upregulated reactive oxygen species (ROS) in L929 cells. Expression of autophagy biomarkers, including beclin-1 and LC3, was significantly increased by 7α,25-DHC treatment in L929 cells. 7α,25-DHC inhibits the phosphorylation of Akt associated with autophagy and increases p53 expression in L929 cells. In addition, inhibition of G-protein-coupled receptor 183 (GPR183), a receptor of 7α,25-DHC, using GPR183 specific antagonist NIBR189 suppressed 7α,25-DHC-induced apoptosis, ROS production, and autophagy in L929 cells. Collectively, GPR183 regulates 7α,25-DHC-induced oxiapoptophagy in L929 cells.

25-Hydroxycholesterol-Induced Oxiapoptophagy in L929 Mouse Fibroblast Cell Line.

25-hydroxycholesterol (25-HC) is an oxysterol synthesized from cholesterol by cholesterol-25-hydroxylase during cholesterol metabolism. The aim of this study was to verify whether 25-HC induces oxiapoptophagy in fibroblasts. 25-HC not only decreased the survival of L929 cells, but also increased the number of cells with condensed chromatin and altered morphology. Fluorescence-activated cell sorting results showed that there was a dose-dependent increase in the apoptotic populations of L929 cells upon treatment with 25-HC. 25-HC-induced apoptotic cell death was mediated by the death receptor-dependent extrinsic and mitochondria-dependent intrinsic apoptosis pathway, through the cascade activation of caspases including caspase-8, -9, and -3 in L929 cells. There was an increase in the levels of reactive oxygen species and inflammatory mediators such as inducible nitric oxide synthase, cyclooxygenase-2, nitric oxide, and prostaglandin E2 in L929 cells treated with 25-HC. Moreover, 25-HC caused an increase in the expression of beclin-1 and microtubule-associated protein 1A/1B-light chain 3, an autophagy biomarker, in L929 cells. There was a significant decrease in the phosphorylation of protein kinase B (Akt) in L929 cells treated with 25-HC. Taken together, 25-HC induced oxiapoptophagy through the modulation of Akt and p53 cellular signaling pathways in L929 cells.

Oxysterol 25-hydroxycholesterol as a metabolic pathophysiological factors of osteoarthritis induces apoptosis in primary rat chondrocytes.

The aim of the present study was to investigate the pathophysiological etiology of osteoarthritis that is mediated by the apoptosis of chondrocytes exposed to 25-hydroxycholesterol (25-HC), an oxysterol synthesized by the expression of cholesterol-25-hydroxylase (CH25H) under inflammatory conditions. Interleukin-1ß induced the apoptosis of chondrocytes in a dose- dependent manner. Furthermore, the production of 25-HC increased in the chondrocytes treated with interleukin-1ß through the expression of CH25H. 25-HC decreased the viability of chondrocytes. Chondrocytes with condensed nucleus and apoptotic populations increased by 25-HC. Moreover, the activity and expression of caspase-3 were increased by the death ligand-mediated extrinsic and mitochondria-dependent intrinsic apoptotic pathways in the chondrocytes treated with 25-HC. Finally, 25-HC induced not only caspase-dependent apoptosis, but also induced proteoglycan loss in articular cartilage ex vivo cultured rat knee joints. These data indicate that 25-HC may act as a metabolic pathophysiological factor in osteoarthritis that is mediated by progressive chondrocyte death in the articular cartilage with inflammatory condition.

Anticatabolic Effects of Morin through the Counteraction of Interleukin-1ß-Induced Inflammation in Rat Primary Chondrocytes.

Morin, a flavonoid isolated from various medicinal herbal plants, has an anti-inflammatory effect. This study aimed to elucidate the anticatabolic effects and cellular mechanism of morin against interleukin-1ß (IL-1ß) in rat primary chondrocytes. Morin at 10-100 µM did not affect the viability of rat primary chondrocytes. Treatment with morin for 21 days ameliorated the IL-1ß-induced decrease in extracellular matrix. Furthermore, treatment with morin attenuated IL-1ß-induced proteoglycan loss in the articular cartilage through suppression of catabolic factors, such as matrix metalloproteinases, inflammatory mediators, and pro-inflammatory cytokines. These data indicated that morin exerted anticatabolic effects that can prevent and reduce progressive degeneration of the articular cartilage, and thus may be a potential candidate treatment for osteoarthritis.

Effects of Platelet-Derived Material (Platelet-Rich Fibrin) on Bone Regeneration.

PURPOSE: The purpose of this study was to evaluate the effects of the growth factor within platelet-rich fibrin (PRF) in proliferation and differentiation of osteoblast and to observe the effectiveness of PRF. MATERIALS AND METHODS: The colorimetric MTT assay, cell live and dead assay, alkaline phosphatase staining and activity assay, alizarine red S, and von Kossa staining were performed. Finally, the alterations of biomarkers associated with bone formation were verified at the mRNA level by quantitative polymerase chain reaction (PCR) and quantitative real-time PCR. In in vivo study, 6 adult mongrel dogs were used. The defect was performed and divided into 3 groups: (1) defect left unfilled, (2) defect filled with only 0.25-g Bio-Oss, and (3) defect filled with 0.25-g Bio-Oss mixed with PRF. RESULTS: MTT and cell live and dead assay showed that PRF did not affect the cell viability in MG-63 cells. The alkaline phosphatase activity, calcification, and mineralization were gradually increased in the MG-63 cells treated with PRF. Furthermore, the mRNA levels of biomarker gene in the MG-63 cells treated with PRF were significantly higher than those of control. In in vivo study, both radiographical and histological evaluations showed that the new bone formations were significantly increased in the defecting bone region transplanted with Bio-Oss and PRF compared with Bio-Oss only at 2 weeks after transplantation. CONCLUSION: PRF can promote the bone regeneration without any complications.

Comparative Study on Osseointegration of Implants After Flap and Flapless Surgery in the Mandible of Dogs.

PURPOSE: The objective of this study was to compare the implant stability and osseointegration of implants using a flap or flapless technique. MATERIAL AND METHODS: Mandibular premolars and molars were extracted from both sides in 6 dogs. After 8 weeks, 4 fixtures were implanted using either a flap or flapless technique. Implant stability quotient was measured on insertion and at 2, 4, and 8 weeks later. The animals were killed while the tissues were histologically analyzed. RESULTS: Implant stability increased for 8 weeks, and no statistically significant differences were observed between the surgical protocols. Bone-implant contact showed 60.27% ± 30.99% for flapless surgery and 59.73% ± 17.12% for flap surgery. And the results of new bone formation area from total area showed 56.07% ± 27.78% for flapless surgery and 57.00% ± 14.66% for flap surgery. There were no statistically significant differences. CONCLUSION: This study showed no significant difference in implant stability as well as osseointegration regardless of flap or flapless technique.

Incidence and Management of Fractured Dental Implants: Case Reports.

The fracture of dental implants is a rare occurrence in clinical settings. Possible causes of implant fracture include design or production flaws, overloaded occlusion force, implant location, metal fatigue, and bone resorption around the implant. This study reports on the successful removal and reimplantation of fractured implants.

Biochanin-A antagonizes the interleukin-1ß-induced catabolic inflammation through the modulation of NFκB cellular signaling in primary rat chondrocytes.

Biochanin-A, a phytoestrogen derived from herbal plants, protected from the IL-1ß-induced loss of proteoglycans through the suppression of matrix degrading enzymes such as matrix metalloproteinase (MMP)-13, MMP-3, MMP-1, and ADAMTS-5 in primary rat chondrocytes and the knee articular cartilage. It also suppressed the expression of IL-1ß-induced catabolic factors such as nitric oxide synthase 2, cyclooxygenase-2, prostaglandin E2, and inflammatory cytokines. Furthermore, biochanin-A suppressed the IL-1ß-induced phosphorylation of NFκB, and inhibited its nuclear translocation in primary rat chondrocytes. These results indicate that biochanin-A antagonizes the IL-1ß-induced catabolic effects through its anti-inflammatory activity that involves the modulation of NFκB signaling.

Implants Displaced Into the Maxillary Sinus: A Systematic Review.

OBJECTIVES: Implant displacement into the maxillary sinus often results from features specific to the posterior maxillary teeth, including poor bone quality and insufficient remaining bone. This study reviews implants displaced into the maxillary sinus, the causes and complications of displacement, and how to remove them, according to when the displacement occurs. MATERIALS AND METHODS: The PubMed, Ovid (MEDLINE), and EMBASE databases were searched using the keywords "displacement," "implant," "maxillary sinus," and "removal" for articles published between January 2000 and July 2013. RESULTS: Twenty-two journal articles were selected; these discussed 49 displaced implants. Most of the implants were displaced into the maxillary sinus during implantation, but resulted in a low incidence of complications, such as maxillary sinusitis. The displaced implants were removed using the Caldwell-Luc approach or a transoral or transnasal endoscopic approach. CONCLUSION: Implants displaced into the maxillary sinus have various causes according to when they are displaced. As displaced implants can cause several complications, transnasal endoscopy is recommended to remove them; however, the implants should be examined thoroughly before selecting the removal method.

Histomorphometric Analysis of Contaminated Autogenous Tooth Graft Materials After Various Sterilization.

PURPOSE: The purpose of this study was to evaluate histomorphometrically contaminated autogenous tooth graft materials, which were resterilized. MATERIALS AND METHODS: The intentional defects (diameter: 8 mm, depth: 4 mm) were formed around implant fixture on the iliac crest of 6 mongrel dogs. Autogenous tooth graft materials were made by extracted premolars. After the contamination of the tooth materials, graft procedure was performed; no contaminated group (control group), contaminated groups (nonsterilization group [group 1], ethylene oxide [EO] gas group [group 2], and autoclave group [group 3]). The bone-to-implant contact (BIC) and the new bone formation rate (NBFR) were evaluated after sacrifice. RESULTS: The BIC and NBFR of groups 1 and 3 were significantly lower than the control group after 4 weeks. The BIC and NBRF of group 3 were significantly lower than the control group after 8 weeks. However, the BIC and NBRF of group 2 was not significantly different comparing with the control group after 4 and 8 weeks. CONCLUSION: Sterilization using EO gas may be more favorable than high-pressure sterilization in cases the reuse of contaminated autogenous tooth graft materials.

Early Bone Formation at a Femur Defect Using CGF and PRF Grafts in Adult Dogs: A Comparative Study.

PURPOSE: The purpose of this study was to compare the predictability of new bone formation using an autologous concentrated growth factor (CGF) graft alone and platelet graft alone. MATERIALS AND METHODS: Four bony defects of 8 mm were formed, and 3.7- × 10-mm implants were placed in the right femur. The platelet-rich fibrin (PRF), CGF, and synthetic bone were grafted to the bone defect area. Enzyme linked immunosorbent assay quantitative analysis and microscopic analysis of the fibrinogen structure were performed. RESULTS: At 4 weeks, the comparisons of each experimental group showed a significant difference between the CGF group and the synthetic bone graft group. When comparing the CGF and allograft material groups, the allograft group showed significantly more new bone formation. In the case of vascular endothelial growth factor, CGF had 1.5 times more than PRF. CGF showed a fibrinogen structure with a constant diameter. CONCLUSION: When applied to a clinical case, CGF is predicted to show better results than PRF.

Biological Effects of the Herbal Plant-Derived Phytoestrogen Bavachin in Primary Rat Chondrocytes.

The aim of this study was to examine the anabolic and anticatabolic functions of bavachin in primary rat chondrocytes. With bavachin treatment, chondrocytes survived for 21 d without cell proliferation, and the proteoglycan content and extracellular matrix increased. Short-term monolayer culture of chondrocytes showed that gene induction of both aggrecan and collagen type II, major extracellular matrix components, was significantly upregulated by bavachin. The expression and activities of cartilage-degrading enzymes such as matrix metalloproteinases and a disintegrin and metalloproteinase with thrombospondin motifs were inhibited significantly by bavachin, while tissue inhibitors of metalloprotease were significantly upregulated. Bavachin inhibits the expression of inducible nitric oxide synthase, a representative catabolic factor, and downregulated the expression of nitric oxide, cyclooxygenase-2, and prostaglandin E2 in a dose-dependent manner in chondrocytes. Our results suggest that the bavachin has anabolic and potent anticatabolic biological effects on chondrocytes, which may have considerable promise in treating articular cartilage degeneration in the future.

Downregulation of adenomatous polyposis coli by microRNA-663 promotes odontogenic differentiation through activation of Wnt/beta-catenin signaling.

MicroRNAs (miRNAs) regulate cell differentiation by inhibiting mRNA translation or by inducing its degradation. However, the role of miRNAs in odontogenic differentiation is largely unknown. In this present study, we observed that the expression of miR-663 increased significantly during differentiation of MDPC-23 cells to odontoblasts. Furthermore, up-regulation of miR-663 expression promoted odontogenic differentiation and accelerated mineralization without proliferation in MDPC-23 cells. In addition, target gene prediction for miR-663 revealed that the mRNA of the adenomatous polyposis coli (APC) gene, which is associated with the Wnt/ß-catenin signaling pathway, has a miR-663 binding site in its 3'-untranslated region (3'UTR). Furthermore, APC expressional was suppressed significantly by miR-663, and this down-regulation of APC expression triggered activation of Wnt/ß-catenin signaling through accumulation of ß-catenin in the nucleus. Taken together, these findings suggest that miR-663 promotes differentiation of MDPC-23 cells to odontoblasts by targeting APC-mediated activation of Wnt/ß-catenin signaling. Therefore, miR-663 can be considered a critical regulator of odontoblast differentiation and can be utilized for developing miRNA-based therapeutic agents.

Histomorphometric analysis of bone formation in bony defects around implants in adult dogs: a comparison of grafts of low and high heat-treated autogenous tooth ash.

PURPOSE: The purpose of this study was to compare the bone formation of autogenous tooth ash treated with different temperatures. MATERIALS AND METHODS: Heat treatment was rendered by powder after extraction of teeth from dogs. The bony defects were made at iliac and resorbable blast medium surfaced implant placement and bone graft was performed; no bone graft group (control group), low heat-treated tooth ash group (group 1), high heat-treated tooth ash group (group 2). Right side had healing periods of 12 weeks, and the left side had 6 weeks. Histomorphometrical analysis was performed at 12 weeks. RESULTS: The control group had poor bone formation and showed large loose connective tissue. Group 1 displayed good healing and bone formation. Group 2 showed higher rate of bone formation than group 1 and the control group. The high heat-treated tooth ash group showed a statistically significant increase in the rate of bone formation in the early stage. CONCLUSION: The heat-treated autogenous tooth ash powder showed excellent new bone formation. The temperature of heat treatment is an important factor in new bone formation. The high heat treatment was the optimal treatment method for making tooth ash than the low heat treatment.

DMP1 and IFITM5 Regulate Osteogenic Differentiation of MC3T3-E1 on PEO-Treated Ti-6Al-4V-Ca2+/Pi surface.

Despite numerous studies on various surface modifications on titanium and its alloys, it remains unclear what kind of titanium-based surface modifications are capable of controlling cell activity. This study aimed to understand the mechanism at the cellular and molecular levels and investigate the in vitro response of osteoblastic MC3T3-E1 cultured on the Ti-6Al-4V surface modified by plasma electrolytic oxidation (PEO) treatment. A Ti-6Al-4V surface was prepared by PEO at 180, 280, and 380 V for 3 or 10 min in an electrolyte containing Ca2+/Pi ions. Our results showed that PEO-treated Ti-6Al-4V-Ca2+/Pi surfaces enhanced the cell attachment and differentiation of MC3T3-E1 compared to the untreated Ti-6Al-4V control but did not affect cytotoxicity as shown by cell proliferation and cell death. Interestingly, on the Ti-6Al-4V-Ca2+/Pi surface treated by PEO at 280 V for 3 or 10 min, MC3T3-E1 showed a higher initial adhesion and mineralization. In addition, the alkaline phosphatase (ALP) activity significantly increased in MC3T3-E1 on the PEO-treated Ti-6Al-4V-Ca2+/Pi (280 V for 3 or 10 min). In RNA-seq analysis, the expression of dentin matrix protein 1 (DMP1), sortilin 1 (Sort1), signal-induced proliferation-associated 1 like 2 (SIPA1L2), and interferon-induced transmembrane protein 5 (IFITM5) was induced during the osteogenic differentiation of MC3T3-E1 on the PEO-treated Ti-6Al-4V-Ca2+/Pi. DMP1 and IFITM5 silencing decreased the expression of bone differentiation-related mRNAs and proteins and ALP activity in MC3T3-E1. These results suggest that the PEO-treated Ti-6Al-4V-Ca2+/Pi surface induces osteoblast differentiation by regulating the expression of DMP1 and IFITM5. Therefore, surface microstructure modification through PEO coatings with Ca2+/Pi ions could be used as a valuable method to improve biocompatibility properties of titanium alloys.

Demethoxycurcumin induces apoptosis via inhibition of NF-κB pathway in FaDu human head and neck squamous cell carcinoma.

Background: Demethoxycurcumin (DMC) is a curcumin analog with antitumor properties. However, its effects have not been investigated in human head and neck squamous cell carcinoma (HNSCC). The aim of the present study was to verify the antitumor effect and cellular signaling pathways of DMC in FaDu HNSCC cells. Methods: 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), cell Live/Dead staining, hematoxylin and eosin staining, DAPI staining, FACS, western blotting, caspase-3 activity assay, and nuclear translocation were performed to verify apoptosis and the cellular signaling pathway of DMC in FaDu cells. Results: DMC increased FaDu cell death, with cells presenting altered morphology and condensed nuclei. DMC increased significantly the apoptotic population of FaDu cells. Sequentially, DMC increased the expression of cleaved caspase-3 and PARP through the up-regulation of pro-apoptotic factors such as FasL, cleaved caspase-8, Bax, Bad, and cleaved caspase-9 and the suppression of anti-apoptotic factors including Bcl-xL and Bcl-2 in FaDu cells. Furthermore, DMC not only suppressed the phosphorylation of NF-κB, but also inhibited the translocation of NF-κB from cytosol to nucleus of FaDu cells. Conclusions: Present study demonstrates that DMC-induced cell death is mediated caspase-dependently by death receptor-mediated extrinsic and mitochondria-dependent intrinsic apoptosis through the inhibition of NF-κB translocation from the cytosol to the nucleus of FaDu cells. DMC is a curcuminoid with antitumor properties that modulates the NF-κB cellular signaling pathway in FaDu cells. Taken together, this study suggests that DMC has a considerable chemotherapeutic potential for HNSCC.

Comparison of Various Time-Related Modifications of Ultraviolet Photofunctionalization on SLA-Treated Titanium Surfaces.

PURPOSE: The purpose of this study was to compare changes in the physicochemical and biologic characteristics of titanium surfaces through short-term re-hydrophobization for 24 hours and ultraviolet (UV) re-irradiation for 24 hours. MATERIALS AND METHODS: Photofunctionalization was performed with four 15-W bactericidal lamps at an intensity of 5.0 mW/cm2 (wavelength = 254 ± 20 nm) on sandblasted, large-grit, acid-etched (SLA)-treated titanium surfaces, which were stored in a sterilized sealed container for 8 weeks to allow enough biologic aging. The duration of the UV irradiation was as follows: irradiation group-UV irradiated for 24 hours; re-hydrophobization group-UV irradiated for 24 hours and then stored in an ambient sterilized medium; and re-irradiation group-UV irradiated for 24 hours followed by storing for 24 hours in an ambient sterilized medium and then UV re-irradiated for 24 hours. The surface characteristics were evaluated with field emission scanning electron microscopy, x-ray photoelectron spectroscopy (XPS), and water contact angle. Cell viability and morphology were measured using fluorescence staining. Alkaline phosphatase (ALP) assay and alizarin red S staining were performed to evaluate the differentiation of osteogenic cells and the mineralization capability. RESULTS: Macroroughness and superimposed microroughness were observed on the disk surfaces in all groups as typically seen on SLA surfaces. The water contact angles were measured to be 1.85, 1.48, and 1.18 degrees for the irradiation group, re-hydrophobization group, and re-irradiation group, respectively, indicating superhydrophilicity. There was no difference in the surface elemental ratio or the spectra of XPS, cell viability, or ALP activity. Although the re-irradiation group had the highest total amount of calcium deposition, there was no statistical significance. CONCLUSION: Within the limitations of the study, improved superhydrophilicity and bioactivity after UV irradiation were maintained during short-term re-hydrophobization and repeated re-irradiation without changing the topography of SLA titanium surfaces.

Classification of postoperative edema based on the anatomic division with mandibular third molar extraction.

PURPOSE: Several investigations have been performed for a postoperative edema after extraction, but the results have been controversial due to low objectivity or poorly reproducible assessments of the edema. The aim of this study was to suggest a classification and patterns of postoperative edema according to the anatomical division associated with extraction of mandibular third molar as a qualitative evaluation method. METHODS: This study was conducted forty-four mandibular third molars extracted and MRI was taken within 48 h after extraction. The postoperative edema space was classified by MRI (one anatomic component-buccinator muscle-and four fascial spaces-supra-periosteum space, buccal space, parapharyngeal space, and lingual space), and evaluated independently by two examiners. The inter-examiner reliability was calculated using Kappa statistics. RESULTS: The evaluation of buccinator muscle edema showed good agreement and the fascial spaces showed constant high agreement. The incidence of postoperative edema was high in the following order: supra-periosteum space (75.00%), buccinator muscle (68.18%), parapharyngeal space (54.55%), buccal space (40.91%), and lingual space (25.00%). CONCLUSION: Postoperative edema could be assessed clearly by each space, which showed a different tendency between the anatomic and fascial spaces.