The influence of simvastatin on osteoblast functionality in the presence of titanium dioxide particles In-vitro.

OBJECTIVE: Leaching of particles from dental titanium implant surfaces into preimplant microenvironment causes detrimental effects on bone cells. The current study investigated influence of simvastatin in mitigating adverse pro-inflammatory effects of titanium dioxide (TiO2) micro (MP) and nano (NP) particles on hFOB 1.19 cells in vitro. DESIGN: Viability of hFOB 1.19 cells following exposure to varying concentrations of TiO2 MPs and NPs and simvastatin were measured by XTT assay. hFOB 1.19 cells were treated with 100 µg/mL of TiO2 MPs, 100 µg/mL of TiO2 NPs, 0.1 µM simvastatin, 100 µg/mL of TiO2 MPs+ 0.1 µM simvastatin and 100 µg/mL of TiO2 NPs+ 0.1 µM simvastatin. After 24 h, ROS was measured by flow cytometry. On day 14, real-time PCR analysis for pro-inflammatory cytokines and bone formation markers was done for TNFα, IL1ß, osteocalcin, ALP, and Col1 markers; while ALP and RANKL/OPG ratio were determined by colorimetric and ELISA assays respectively. Further, mineralization study using Alizarin Red S staining (ARS) and calcium quantification were performed. RESULTS: Exposure of hFOB to TiO2 MPs and NPs generated ROS and reduced cell viability significantly, with upregulation of pro-inflammatory markers TNFα and IL1ß and downregulation of bone formation markers OC and increased RANKL/OPG ratio and lowered degree of mineralization. Treatment with 0.1 µM of simvastatin treatment reversed the effects by mitigating oxidative stress, dampening pro-inflammatory markers, upregulation of bone formation markers, lowering RANKL/OPG ratio and increasing degree of mineralization. CONCLUSION: Simvastatin possesses antioxidant, anti-inflammatory, and pro-osteogenic properties that may support bone healing around titanium implants.

Impact of Bone Morphogenetic Protein 7 and Prostaglandin receptors on osteoblast healing and organization of collagen.

PURPOSE: This study seeks to investigate the impact of co-administering either a Prostaglandin EP2 receptor agonist or an EP1 receptor antagonist alone with a low dose BMP7 on in vitro healing process, collagen content and maturation of human osteoblasts. METHODOLOGY: Human osteoblast cells were used in this study. These cells were cultured and subjected to different concentrations of Prostaglandin EP2 receptor agonist, EP1 receptor antagonist, BMP7, Control (Ct) (Vehicle alone), and various combinations treatments. Cell viability at 24, 48 and 72 hours (h) was evaluated using the XTT assay. A wound healing assay was conducted to observe the migration ability of human osteoblast cells. Additionally, Sirius red staining and Fourier-Transform Infrared Spectroscopy Imaging (FT-IR) was employed to analyze various parameters, including total protein concentration, collagen production, mature collagen concentration, and mineral content. RESULTS: The combination of low dose BMP7 and Prostaglandin EP2 receptor agonist resulted to the lowest cell viability when compared to both the Ct and individual treatments. In contrast, the Prostaglandin EP1 receptor antagonist alone showed the highest cellular viability at 72 h. In the wound healing assay, the combined treatment of low dose BMP7 with the Prostaglandin EP2 receptor agonist and EP1 receptor antagonist showed a decrease in human osteoblast healing after 24 h. Analysis of FT-IR data indicated a reduction in total protein content, collagen maturity, collagen concentration and mineral content in combination treatment compared to the single or Ct treatments. CONCLUSION: The combination of a Prostaglandin EP2 receptor agonist or an EP1 receptor antagonist when combined with low dose BMP7 significantly hinders both human osteoblast healing and collagen maturity/concentration in comparison to low dose BMP7 treatment alone.

Response of human peripheral blood monocyte-derived macrophages (PBMM) to demineralized and decellularized bovine bone graft substitutes.

The performance of apparently biocompatible implanted bovine bone grafts may be compromised by unresolved chronic inflammation, and poor graft incorporation leading to implant failure. Monitoring the intensity and duration of the inflammatory response caused by implanted bone grafts is crucial. In this study, the ability of demineralized (DMB) and decellularized (DCC) bovine bone substitutes in initiating inflammatory responses to peripheral blood monocyte-derived macrophages (PBMMs) was investigated. The response of PBMMs to bone substitutes was evaluated by using both direct and indirect cell culture, reactive oxygen species (ROS) generation, apoptosis, immunophenotyping, and cytokine production. Analysis of DMB and DCC substitutes using scanning electron microscope (SEM) showed a roughened surface with a size ranging between 500 and 750 µm. PBMMs treated with DMB demonstrated cell aggregation and clumping mimicking lipopolysaccharide (LPS) treated PBMMs and a higher proliferation ability (166.93%) compared to control (100%) and DCC treatments (115.64%; p<0.001) at 24h. This was associated with a significantly increased production of intracellular ROS in PBMMs exposed to DMB substitutes than control (3158.5 vs 1715.5; p<0.001) and DCC treatment (2117.5). The bone substitute exposure also caused an increase in percentage apoptosis which was significantly (p<0.0001) higher in both DMB (27.85) and DCC (29.2) treatment than control (19.383). A significant increase in proinflammatory cytokine expression (TNF-α: 3.4 folds; p<0.05) was observed in DMB substitute-treated PBMMs compared to control. Notably, IL-1ß mRNA was significantly higher in DMB (21.75 folds; p<0.0001) than control and DCC (5.01 folds). In contrast, DCC substitutes exhibited immunoregulatory effects on PBMMs, as indicated by the expression for CD86, CD206, and HLDR surface markers mimicking IL-4 treatments. In conclusion, DMB excites a higher immunological response compared to DCC suggesting decellularization process of tissues dampen down inflammatory reactions when exposed to PBMM.

Pharmacological inhibition of endoplasmic reticulum stress mitigates osteoporosis in a mouse model of hindlimb suspension.

Hindlimb suspension (HLS) mice exhibit osteoporosis of the hindlimb bones and may be an excellent model to test pharmacological interventions. We investigated the effects of inhibiting endoplasmic reticulum (ER) stress with 4-phenyl butyrate (4-PBA) on the morphology, physicochemical properties, and bone turnover markers of hindlimbs in HLS mice. We randomly divided 21 male C57BL/6J mice into three groups, ground-based controls, untreated HLS group and 4-PBA treated group (HLS+4PBA) (100mg/kg/day, intraperitoneal) for 21 days. We investigated histopathology, micro-CT imaging, Raman spectroscopic analysis, and gene expression. Untreated HLS mice exhibited reduced osteocyte density, multinucleated osteoclast-like cells, adipocyte infiltration, and reduced trabecular striations on micro-CT than the control group. Raman spectroscopy revealed higher levels of ER stress, hydroxyproline, non-collagenous proteins, phenylalanine, tyrosine, and CH2Wag as well as a reduction in proteoglycans and adenine. Furthermore, bone alkaline phosphatase and osteocalcin were downregulated, while Cathepsin K, TRAP, and sclerostin were upregulated. Treatment with 4-PBA partially restored normal bone histology, increased collagen crosslinking, and mineralization, promoted anti-inflammatory markers, and downregulated bone resorption markers. Our findings suggest that mitigating ER stress with 4-PBA could be a therapeutic intervention to offset osteoporosis in conditions mimicking hindlimb suspension.

Correction: Evaluation of the osteogenic potential of demineralized and decellularized bovine bone granules following implantation in rat calvaria critical-size defect model.

[This corrects the article DOI: 10.1371/journal.pone.0294291.].

Evaluation of the osteogenic potential of demineralized and decellularized bovine bone granules following implantation in rat calvaria critical-size defect model.

The aim of this study was to compare the ability of demineralized (DMB) and decellularized (DCC) bovine bone granules to support bone regeneration in rat calvaria critical-size defects. DMB and DCC were prepared using a previously published method. The granule size used ranged between 500 and 750 µm. A total of forty-eight Sprague-Dawley rats were divided into two groups (n = 24). A pair of 5 mm diameter defects were created on the calvaria of the rats in the right and left parietal bone in both groups. Group A animals received DMB granules and Group B received DCC granules in the right parietal defect side while the left parietal untreated defect acted as sham surgery for both groups. Four animals per group were euthanized in a CO2 chamber at day 7, 14 and 21 post-surgery and the calvaria implantation site biopsy harvested was subjected to osteogenic gene expression analysis. Another four animals per group were euthanized at days 15, 30 and 60 post surgery and the calvaria implantation site biopsy harvested was subjected to histological, immunohistochemistry, RAMAN spectroscopy and Micro-CT analysis at the mentioned time points. Statistical analysis was conducted using t-tests and ANOVA. Histomorphometry showed significantly higher new bone formation in the DCC sites (p<0.05) compared to DMB. Both DMB and DCC implantation sites showed distinct staining for osteocalcin and osteopontin proteins compared to their respective sham sites. By day 21 after implantation, DCC sites demonstrated significantly elevated mRNA levels of osteonectin (p<0.001), osteopontin (p<0.001), osteocalcin (p<0.0001), ALP (p<0.01), and BMP-2 (p<0.001) compared to DMB. However, VEGF expression showed no significant differences at this time point between the two groups. Micro-CT analysis also showed enhanced defect closure and higher bone density in DCC implanted sites while RAMAN spectra demonstrated increased abundance of collagen and bone minerals, especially, PO43- ions than DMB. In conclusion, both DMB and DCC granules demonstrated favorable osteogenic potential in critical-sized defects, with DCC exhibited superior osteoconductive, osteoinductive and osteogenesis properties.

Effects of twin-block appliance on upper airway parameters in OSA children with class II malocclusion and mandibular retrognathia: a CBCT study.

Twin-block appliance had been advocated as a potential treatment option in paediatric obstructive sleep apnoea (OSA) due to their favourable effect in enhancing upper airway parameters and improving OSA symptoms. The aim of this study was to evaluate the effect of twin-block appliance therapy on upper airway parameters/dimensions and the apnoea-hypopnea indexes (AHIs) in OSA children with class II mandibular retrognathic skeletal malocclusion using cone-beam computed tomography. This prospective longitudinal study comprised 34 polysomnography-proven OSA growing children with class II mandibular retrognathic skeletal malocclusion between the ages of 8 and 12 years who had completed myofunctional twin-block therapy and matched corresponding controls. The upper airway was segmented into the nasopharynx, oropharynx, and hypopharynx, and the effect of twin-bock treatment on upper airway parameters/dimensions was assessed pre- and posttreatment using CBCT analysis, while a second standard overnight PSG was performed to determine changes in the AHI. At the nasopharynx level, minimal (nonsignificant) increases in all variables were observed within the twin-block group and between the groups (P > 0.05). At the level of the oropharynx, all variables increased significantly in the treatment group and between groups (P < 0.001), but these increases were nonsignificant in the control group. At the level of the hypopharynx, only the minimum cross-sectional area (MCA) increased significantly in the treatment group (P = 0.003). The change in MCA was also significant between the groups (P = 0.041). In addition, the upper airway length increased significantly in the twin-block group (P = 0.0154), and the AHI decreased by 74.8% (P < 0.001). CONCLUSION: Correction of class II mandibular retrognathic skeletal malocclusion with twin-block appliance resulted in a significant increase in upper airway volume, MCA, anteroposterior and lateral distances of the MCA at the level of the oropharynx, MCA at the level of the hypopharynx and upper airway length, and a significant decrease in AHI, but it had no effect on nasopharynx parameters. WHAT IS KNOWN: • CBCT imaging has been shown to be an effective and precise diagnostic tool for analyzing the upper airways and craniofacial structures. • Twin block appliance may be an effective treatment modality in children with OSA. WHAT IS NEW: • Minimal cross-sectional area of upper ways may be the most relevant potential parameter when explaining how the upper airway anatomy plays role of in the pathogenesis of pediatric OSA. • Twin block appliance induced favorable changes in upper airway morphology (oropharynx area mainly) and respiratory parameters in OSA children with class II malocclusion.

Molecular pathogenicity of 1-nonadecene and L-lactic acid, unique metabolites in radicular cysts and periapical granulomas.

Recently, 1-nonadecene and L-lactic acid were identified as unique metabolites in radicular cysts and periapical granuloma, respectively. However, the biological roles of these metabolites were unknown. Therefore, we aimed to investigate the inflammatory and mesenchymal-epithelial transition (MET) effects of 1-nonadecene, and the inflammatory and collagen precipitation effects of L-lactic acid on both periodontal ligament fibroblasts (PdLFs) and peripheral blood mononuclear cells (PBMCs). PdLFs and PBMCs were treated with 1-nonadecene and L-lactic acid. Cytokines' expression was measured using quantitative real-time polymerase chain reaction (qRT-PCR). E-cadherin, N-cadherin, and macrophage polarization markers were measured using flow cytometry. The collagen, matrix metalloproteinase (MMP)-1, and released cytokines were measured using collagen assay, western blot, and Luminex assay, respectively. In PdLFs, 1-nonadecene enhances inflammation through the upregulation of some inflammatory cytokines including IL-1ß, IL-6, IL-12A, monocyte chemoattractant protein (MCP)-1, and platelet-derived growth factor (PDGF) α. 1-Nonadecene also induced MET through the upregulation of E-cadherin and the downregulation of N-cadherin in PdLFs. 1-Nonadecene polarized macrophages to a pro-inflammatory phenotype and suppressed their cytokines' release. L-lactic acid exerted a differential impact on the inflammation and proliferation markers. Intriguingly, L-lactic acid induced fibrosis-like effects by enhancing collagen synthesis, while inhibiting MMP-1 release in PdLFs. These results provide a deeper understanding of 1-nonadecene and L-lactic acid's roles in modulating the microenvironment of the periapical area. Consequently, further clinical investigation can be employed for target therapy.

Evaluation of decellularization process for developing osteogenic bovine cancellous bone scaffolds in-vitro.

Current immunological issues in bone grafting regarding the transfer of xenogeneic donor bone cells into the recipient are challenging the industry to produce safer acellular natural matrices for bone regeneration. The aim of this study was to investigate the efficacy of a novel decellularization technique for producing bovine cancellous bone scaffold and compare its physicochemical, mechanical, and biological characteristics with demineralized cancellous bone scaffold in an in-vitro study. Cancellous bone blocks were harvested from a bovine femoral head (18-24 months old) subjected to physical cleansing and chemical defatting, and further processed in two ways. Group I was subjected to demineralization, while Group II underwent decellularization through physical, chemical, and enzymatic treatments. Both were then freeze-dried, and gamma radiated, finally producing a demineralized bovine cancellous bone (DMB) scaffold and decellularized bovine cancellous bone (DCC) scaffold. Both DMB and DCC scaffolds were subjected to histological evaluation, scanning electron microscopy/energy-dispersive X-ray spectroscopy (SEM/EDS), fourier-transform infrared spectroscopy (FTIR), quantification of lipid, collagen, and residual nucleic acid content, and mechanical testing. The osteogenic potential was investigated through the recellularization of scaffolds with human osteoblast cell seeding and examined for cell attachment, proliferation, and mineralization by Alizarin staining and gene expression. DCC produced a complete acellular extracellular matrix (ECM) with the absence of nucleic acid content, wider pores with extensive interconnectivity and partially retaining collagen fibrils. DCC demonstrated a higher cell proliferation rate, upregulation of osteogenic differentiation markers, and substantial mineralized nodules production. Our findings suggest that the decellularization technique produced an acellular DCC scaffold with minimal damage to ECM and possesses osteogenic potential through the mechanisms of osteoconduction, osteoinduction, and osteogenesis in-vitro.

The Essential Role of 17-Octadecynoic Acid in the Pathogenesis of Periapical Abscesses.

INTRODUCTION: Periapical abscesses are 1 of the most frequent pathologic lesions in the alveolar bone. Recently, we have identified 17-octadecynoic acid (17-ODYA) as the highest unique metabolite in periapical abscesses. Therefore, the aim of this study was to investigate the immunologic and pathophysiological roles of this metabolite in the initiation and development of periapical abscesses. METHODS: Periodontal ligament fibroblasts and peripheral blood mononuclear cells were treated with 17-ODYA. Gene expression analysis and interleukin (IL)-8 release were determined using quantitative real-time polymerase chain reaction and enzyme-linked immunosorbent assay. Macrophage polarization and cytokine release were also determined using flow cytometry and Luminex bioassay (R&D Systems, Minneapolis, MN), respectively. RESULTS: In periodontal ligament fibroblasts, 17-ODYA caused significant (P < .0001) up-regulation of IL-1α, IL-1ß, IL-6, matrix metalloproteinase-1, and monocyte chemoattractant protein-1 at 10 µmol/L after 6 days of treatment and up-regulation of platelet-derived growth factor alpha and vascular endothelial growth factor alpha at all tested concentrations after 2 days of treatment. In peripheral blood mononuclear cells, 17-ODYA significantly increased the expression of IL-1α, IL-1ß, IL-6, matrix metalloproteinase-1, and monocyte chemoattractant protein-1 at 10 µmol/L (P < .0001) and vascular endothelial growth factor alpha and platelet-derived growth factor alpha at 1 µmol/L 17-ODYA (P < .0001). 17-ODYA polarized macrophages toward a proinflammatory phenotype (M1) and suppressed the release of pro- and anti-inflammatory cytokines. 17-ODYA significantly enhanced the release of IL-8. CONCLUSIONS: This study was the first to identify the pathologic role of 17-ODYA in the development of periapical abscesses. The results of this study are important in shedding light on the pathogenesis of periapical abscesses in relation to microbial metabolites.

Impact of exposure of human osteoblast cells to titanium dioxide particles in-vitro.

Titanium Dental implant is the most successful treatment modality to replace missing teeth today. Although titanium is considered biologically biocompatible, strong, and corrosion-free, the risk of implant failure continues due to bone loss at the expense of optimum oral health. Current research points toward the presence of titanium dioxide (TiO2) particles leached from dental implant surface, which occurred due to mechanical and chemical insults on the surface. This study aimed to investigate the influence of TiO2 particles of different sizes leaching from implant surfaces on Human Osteoblast cells (HOB) in-vitro. Titanium dioxide particles in both nano (NPs) and micro (MPs) size and at different concentrations were introduced to human osteoblast cells with and without treatment with vitamin C. Production of ROS was measured using H2DCFDA cellular ROS Assay Kit and MCP-1 and IL-8 cytokines released were assayed at 24 h time point using ELISA technique. Results showed a dose dependent increase in ROS production following exposure of HOB to both nano and micro particles. MCP-1 and IL-8 were released and there was minimal difference between the amount generated by nano compared with micro size particles. Treatment of HOB with antioxidant vitamin C demonstrated a significant reduction in the generation of ROS. At the same time, MCP-1 release was reduced significantly for the 100 µg/mL TiO2 NPs and MPs after Vitamin C treatment while IL-8 release increased significantly. This study suggests a positive role played by antioxidants in the control of ROS generation and chemokines production in the peri-implant tissue environment.

The efficacy of salivary Histatin-1 protein in wound closure of nicotine treated human periodontal ligament fibroblast cells - In vitro study.

OBJECTIVES: The aims of this study were to investigate the efficacy of Histatin-1 in wound closure as well as effects on gene expression of nicotine-treated human Periodontal Ligament Fibroblast cells (HPDL) in vitro. DESIGN: HPDL grown in 2.5% culture medium treated with 10 ng/ml Histatin - 1 in the presence/absence of 0.5 µM nicotine were subjected to wound assay and migration was studied at 0 h, 6 h, 12 h and 24 h. Cells grown in 2.5% medium served as control. Cell migration was studied by wound gap and transwell migration assays. The effect of Histatin-1 on expression of matrix metalloproteinase 8 (MMP-8), insulin-like growth factor 1 (IGF-1), transforming growth factor beta (TGF-ß), collagen type I (COL1) and plasminogen activator inhibitor 1 (PAI-1) were studied. RESULTS: Histatin-1 treatment significantly decreased percentage wound gap at 12 h (62.96 ± 3.22 vs 79.23 ± 1.73; p < 0.05) and at 24 h (38.78 ± 7.59 vs 75.21 ± 4.94; p < 0.001) compared with controls. In nicotine+Histatin-1 treated cells, wound gap decreased to 70.2 ± 2.9% (p < 0.01) at 24 h compared to nicotine alone in which 82 ± 1.64% of wound gap was retained. Transwell migration assays showed significant migration of HPDL with Histatin-1 (p < 0.05). Gene expression demonstrated significant upregulation for IGF-1, TGF ß, COL1 and PAI-1 with Histatin-1. CONCLUSION: Histatin-1 significantly mitigated the effect of nicotine in wound healing assay involving HPDL fibroblast cells at 24 h. Histatin-1 aided wound closure is attributed to the upregulation of IGF-1, TGF ß, COL1, and PAI-1 genes.

Impact of tribocorrosion and titanium particles release on dental implant complications - A narrative review.

Titanium particles as a product of degradation have been detected in periimplant oral tissues and it has been assumed that implants were the source of these particles. Periimplantitis sites had higher concentrations of particles in comparison to healthy implant sites. Several factors have been identified in the degradation of dental implant surface, such as mechanical wear, contact with chemical agents, and the effects of biofilm adhesion. Titanium particles silently prompt the immune-system activation and generate a pro-inflammatory response in macrophages, T lymphocytes and monocytes. During the activation, inflammatory cytokines are released including, granulocyte-macrophage colony-stimulating factor (GM-CSF), prostaglandin, and TNF-α, IL-1ß, IL-6. The nanoparticles depict unique features such as high level of biological reactivity and potentially harmful compared to microparticles since they have a relatively greater surface area to volume ratio. Allergic response to titanium as a cause of implant failure has not been well documented. Evidence demonstrating biological complication due to titanium particles release includes peri-implant tissue inflammation that lead terminally to implant loss. There is a biological probability for a relation between the presence of titanium particles and ions, biological complication, and corrosion, but there is no justifiable evidence for unidirectional series of causative actions.

Tonsil Size and Mallampati Score as Clinical Predictive Factors for Obstructive Sleep Apnea Severity in Children.

AIM AND OBJECTIVE: The aim of this study was to determine the clinical utility of body mass index (BMI), tonsil size, and Mallampati scoring in predicting both the presence of and severity of pediatric obstructive sleep apnea (OSA). MATERIALS AND METHODS: This prospective cross-sectional study comprised 78 growing children in the age range of 11-14 years with polysomnography (PSG)-proven OSA and 86 non-OSA corresponding controls. BMI, tonsil size (Friedman grading scale), and Mallampati score were determined for both groups, and related differences were assessed with a t-test, while their independent association with OSA severity was tested with a regression analysis. Statistical significance was set at p <0.05. RESULTS: Male gender, BMI, tonsil size, and Mallampati score were significantly higher in the OSA group (p < 0.05). A significant correlation was recorded between the Mallampati score and OSA severity (p < 0.01), but not with BMI or tonsil size (p > 0.05). For every 1-point increase in the Mallampati scale, the apnea-hypopnea index (AHI) increased by more than five events per hour in the bivariate analysis and by more than three events per hour in the multivariate analysis. CONCLUSION: Male gender, increased BMI, high tonsil, and Mallampati scores were clinical indicators of the presence of OSA. However, only Mallampati scale had a significant association with OSA severity. Clinical diagnostic indicators should be established and encouraged especially in community-based studies. CLINICAL SIGNIFICANCE: Clinical diagnostic indicators are very useful in examining and screening children who are at risk of developing OSA as PSG is expensive and unsuitable for universal use in the pediatric population.

Impact of titanium dioxide particle size on macrophage production of intracellular reactive oxygen species.

OBJECTIVES: The aim of this study was to investigate the response of THP-1 monocyte-derived macrophages following exposure to titanium dioxide nanoparticles (TiO2 NPs) and microparticles (TiO2 MPs) in an in vitro system. DESIGN: THP-1 monocytes were maintained in RPMI medium and transformed into M0 macrophages using Phorbol 12-myristate 13-acetate (PMA). TiO2 particle size characterization was performed using scanning electron microscopy (SEM) and dynamic light scattering (DLS) technology. A viability study using an XTT assay was performed by treating THP-1-derived macrophages with TiO2 NPs (<100 nm) and TiO2 MPs (<5 µm) at concentrations ranging from 100, 50, 25, 12.5, 6.25 and 3.125 µg/mL. Macrophages were then treated with three different concentrations of NPs and MPs (5, 20 or 100 µg/mL) for 24 h, and ROS production and TiO2 particle cellular uptake were measured using ROS assays and flow cytometry, respectively. RESULTS: There was no significant change in the viability of THP-1 monocytes after treatment with TiO2 NPs and MPs. The uptake of both particles was confirmed and showed an increase in ROS generation, and the MPs produced more ROS than NPs. The increase in ROS generation with NPs was concentration-dependent. CONCLUSION: Uptake of TiO2 NPs and MPs in macrophages at subcytotoxic levels generate ROS in a size- and dose-dependent manner.

Management of dry socket with low-level laser therapy.

OBJECTIVE: The aim of this study is to investigate the efficacy of delivering low-level laser therapy (LLLT) in the management of dry socket at University Dental Hospital Sharjah. MATERIALS AND METHOD: Forty-five patients with dry socket were divided into two treatment groups. Group I dry socket patients (n = 30) received conventional treatment while group II patients (n = 15) were irradiated with LLLT at a setting of 200-mW, 6-J, continuous-wave mode using an R02 tipless handpiece (Fotona Er:YAG, Europe), on the buccal, lingual, and middle surfaces of the socket for 30 s from a delivery distance of 1 cm. Pain score and quantification of granulation tissue in the socket were recorded at 0, 4, and 7 days post-dry socket treatment. RESULTS: Results showed that the LLLT-irradiated group II sockets showed a much lower VAS pain score of 1-2 as early as day 4, and a richer amount of granulation tissue compared to the conventional treated group I socket. The amount and rate of granulation tissue formation in the dry socket are inversely proportional to the pain score showing significant clinical effectiveness of LLLT on promoting the healing of the dry socket, with improvement in symptoms (P = .001). Conventionally treated dry sockets take at least 7 days to match the effective healing of an LLLT-irradiated dry socket. CONCLUSION: LLLT irradiation influences biomodulation of dry socket healing by dampening inflammation, promoting vascularization, stimulating granulation, and controlling pain symptoms. CLINICAL RELEVANCE: LLLT may be an additional effective tool for managing dry sockets in general dental practice.

Investigation of the effect of a time delay on the characteristics and survival of dental pulp stem cells from extracted teeth.

OBJECTIVES: This study investigates the post-extraction storage period of human dental pulp stem cells (hDPSCs) for stem cell banking by investigating the viability, function, mineralization, and gene expression of hDPSCs isolated from extracted teeth after 1 h, 6 h and 24 h post-tooth extraction. DESIGN: hDPSCs were extracted from the pulp of impacted third molar teeth after 1 h, 6 h, and 24 h after extraction. The mesenchymal stem cell (MSCs) properties of three groups of cells were analyzed using flow cytometry. Cell morphology and proliferation were analyzed using a light microscope and an MTT assay. The viability, function, mineralization, and gene expression of hDPSCs of 1 h, 6 h, and 24 h groups were also assessed. RESULTS: The delayed harvesting of hDPSCs for 1, 6 or 24 h caused a 31 % reduction in mineral nodule formation and a reduction in the gene expression of osteocalcin (OCN) and vascular endothelial growth factor-alpha (VEGFA). However, the 1, 6 or 24 h, time delay had little effect on MTT cell proliferation, cell viability or morphology. The delayed of harvesting of hDPSCs for 1, 6 or 24 h also had little effect on the expression of MSCs positive (CD44, CD106, CD90) or negative surface markers (CD45 and CD11b). CONCLUSIONS: Our results suggest that a 24 h delay in harvesting hDPSCs from extracted teeth can reduce their mineralization and gene activity but does not markedly reduce survival. Quicker hDPSCs harvesting is likely to yield more useful hDPSCs for experimentation and clinical treatment.

The Efficacy of Concentrated Growth Factor in the Healing of Alveolar Osteitis: A Clinical Study.

BACKGROUND: A dry socket also referred to as alveolar osteitis (AO) is a common postoperative complication following tooth extraction, due to the disruption of the clot within the wound. This study aimed to evaluate the efficacy of concentrated growth factor (CGF) in the healing of alveolar osteitis following tooth extraction. METHODS: The study was conducted at University Dental Hospital Sharjah, UAE. Patients undergoing tooth extraction at the oral surgery clinic were advised to return immediately if they suffer from pain. Over the following first week after tooth extraction, patients who reported pain symptoms were recalled and all dry sockets were identified. The patients were divided into two groups. Group I patients received conventional treatment with socket curettage and saline irrigation only, while in group II CGF was inserted into the socket. Both groups were observed for pain score and quantification of granulation tissue formation. RESULTS: A total of 40 dry socket patients, aged between 18 and 60 years, from a total of 1,250 patients, were included in the study. 30 patients were given conventional treatment while another 10 patients were given CGF. Patients who received CGF had a pain score of 7-10 at presentation, and the pain score dropped to 0-3 on day 4 and further improved to 0-1 on day 7 (p = 0.001). Granulation tissue formation appeared in the conventional group I on day 7 while the CGF group II showed earlier granulation tissue formation by day 4 (p = 0.001). The posttreatment pain score is inversely proportional to the amount and rate of granulation tissue formation in the socket. CONCLUSION: The study suggests that delivery of CGF into a dry socket helps relieve pain and expedite the wound healing process as shown by a statistically much lower pain score and earlier and more rapid formation of granulation tissue when compared to the conventional alveolar osteitis therapy.

Temporomandibular Joint Ankylosis Leading to Obstructive Sleep Apnea.

Temporomandibular joint ankylosis in children commonly lead to difficulty in feeding, poor oral hygiene, retrognathic mandible and obstructive sleep apnea. Surgical release of the ankylosis has always been the standard treatment. The authors report a 12 year old boy with unilateral temporomandibular joint ankylosis and obstructive sleep apnea underwent surgical release of the ankylosis with successful gain in mouth opening. However, he continued to suffer from obstructive sleep apnea as confirmed by post-operative polysomnography. Orthognathic surgery for mandibular advancement is not favorable due to his young age and mandibular distraction osteogenesis was not a choice. A mandibular advancement device similar to orthodontic myofunctional appliance was the preferred choice in the post-operative period while waiting for definitive retrognathia surgical treatment after skeletal maturity. Surgical release of temporomandibular joint ankylosis corrects the oral problem but does not adequately address the narrow pharyngeal airway space. Assessment of pharyngeal airway with a high suspicion of obstructive sleep apnea is mandatory in the management of TMJ ankylosis.

Dislodged Bonded Molar Tube into Wound during Orthognathic Surgery.

INTRODUCTION: Dislodgement of orthodontic appliance into operation wounds may occur while performing orthognathic surgery. Its occurrence is commonly associated with bonded upper molar tube. CASE REPORT: A 25-year-old gentleman presented with recurrent upper right vestibular abscess three months following a bimaxillary orthognathic surgery. A bonded molar orthodontic tube had dislodged into the wound during the operation. The clinical presentation initially mimics an odontogenic infection until our investigations revealed that it originated from the dislodged appliance. The abscess was drained, the wound site was explored, and the molar tube and neighbouring rigid fixation plates and screws were removed. The patient recovered well following the procedure. CONCLUSION: Dislodged metal orthodontic appliance in oral wound acts as a foreign body that may exert allergic reactions, infection, or inflammation. Pre- and postoperative intraoral examination of fixed orthodontic appliances including its count should be recorded in orthognathic surgery protocol.