The aim of this work is to evaluate the antibacterial effect and biocompatibility of zinc oxide (ZnO) nanopaticles and graphite-type carbon (Gt) microparticles commercial powders. SEM analysis was performed to assess particles morphology. The antibacterial behavior was studied against Staphylococcus aureus (Staph. Aureus) (bacterial strain ATCC 29213) and TEM analysis of bacteria was performed to determine ultrastructural alterations; in addition, biocompatibility was evaluated in subcutaneous tissue of Wistar rats at 3, 7 and 28 d. ZnO and Gt powders exhibited antibacterial activity while TEM images of Staph. aureus showed membrane disruption followed by the release of internal content. Also, an electron-light region within the cytoplasm was observed for microorganisms treated with ZnO. Regarding biocompatibility, Gt samples induced a foreign body reaction response with presence of giant cells whereas ZnO samples showed fibroblastic connective tissue with chronic inflammatory cells and new small vessels. Also, collagen fibers and lack of capsule was observed by Trichome Masson stain. Thus, ZnO improved wound healing by enhancing tissue regeneration in contrast with calcium hydroxide control sample response which showed a fibrous tissue scar. Hence, ZnO nano-powder seems to be a potential material in the regenerative endodontic field.
We previously reported that miR-183 was downregulated during the direct conversion of dental pulp cells to insulin-producing cells. To further elucidate the role of miRNA regulation in dental pulp cells during this process, we examined the effect of miR-183 inhibition. Insulin expression was detected in induced cells 72 hours after ectopic expression of miR-183 inhibitor. The expression levels of insulin 1 and insulin 2 mRNA increased 1.7-fold and 1.6-fold, respectively. Insulin copy number estimates, following miR-183 inhibition, showed more than 10 copies each of insulin 1 and insulin 2. These data suggest that miR-183 downregulation induces the direct conversion of dental pulp cells to insulin-producing cells.
The aim of this study is to evaluate the effect of Low Intensity Pulsed Ultrasound (LIPUS) on marginal bone loss and osseointegration of dental implant using Cone Beam CT (CBCT) image analysis, torque wrench and Resonance Frequency Analysis (RFA) techniques. The study sample comprised of 22 patients; who were divided randomly into two equal groups (n=11). Each patient received one dental implant placed in the maxillary premolar region. Following first stage implant surgery, in Group I, LIPUS was delivered to the implant operation site for 10 weeks before loading and for another 10 weeks post loading, while in control Group II, the implant wound was allowed to heal in the conventional way. The patients in both groups were followed up at 3 months and 6 months using clinical and radiological assessments that comprised of CBCT image analysis, Torque wrench and RFA values. The peri-implant bone height and width were measured and compared at three different views (coronal, sagittal and axial) using CBCT at day 0, 3 months and 6 months. Statistical analysis using repeated measure ANOVA with significance level of p<0.05 was employed for the evaluation and comparison within the same group and among the two different groups based on specific time points. There was an increase in marginal bone level in Group I at six months post-operative and marginal bone lone loss in Group II within the same time interval. The marginal bone gain in Group I was statistically significant at the buccal bone plate site. In both groups, there was an increase in torque wrench and RFA values but the increase was more significant in Group I (LIPUS treated) compared to control group at six months post-operative. LIPUS promote bone healing around dental implant and can be utilized as a treatment modality to save implant with questionable stability and to enhance bone regeneration and quality osseointegration
From the perspective of excellent biocompatibility and osteoconductivity of hydroxyapatite (HA), the frequency of use of HA implants has been steadily increasing in recent years. But the coating layer of certain commercialized HA implants may not be primarily composed of HA, and it may be assumed that the coating layers, contained some HA components, are automatically categorized to the HA implant. The characteristics of the implant to vital tissues are attributable to the properties of the surface components of the implant. Scanning electron microscope (SEM) observations and X-ray diffraction (XRD) analyses of the HA coating have been performed previously, but SEM has some difficulties in showing clear images of the HA crystal due to the influence of coating conditions etc., and the results obtained from XRD are not limited to the surface where contact with vital tissues, but also exhibit the inner components of the coating layer. Therefore, it might be assumed that reports limited to the top surface of the HA coating have still not been published. In this study, AFM observations, and XPS and micro-XRD analyses were performed on the top surface of five commercially available HA implants. AFM results showed that HA crystals were clearly observed on the surface of two samples. XPS and micro-XRD analyses exhibited that HA was detected in all the samples, but other substances including Ti, TiO2, CaTiO3, etc., were also confirmed in several samples. These results showed that HA was present on the top surface of all HA implants, and also indicated that all implants might exhibit some sort of biocompatibility and osteoconductivity due to their bioactive natures caused by HA.
The present study deals with the circadian expression of clock genes in acute cardiac death to examine any correlation between clock gene expression and catecholamines. A total of 36 subjects, who died of acute ischemic heart disease (AIHD, n = 10), acute myocardial infarction (AMI, n = 11), and recurrent myocardial infarction (RMI, n = 15) and underwent autopsy within 2 days after death, were included in this study. The mRNA expression levels of the clock genes BMAL1, PER2, and REV-ERBα were determined in the post-mortem heart tissue. Catecholamine levels in blood obtained from the right heart were measured. Furthermore, the cellular localization of clock proteins was assessed by immunohistochemistry, and protein levels in the heart tissue were also measured by Western blotting. In our cases of AIHD death, BMAL1 and PER2 exhibited trimodal expression patterns; however, the trimodal expression pattern of PER2 was antiphasic to that of BMAL1. PER2 expression correlated with adrenaline and noradrenaline levels. In deaths from AMI, BMAL1 and PER2 exhibited antiphasic trimodal and bimodal expressions, respectively, and BMAL1 expression correlated with adrenaline and noradrenaline levels. In RMI, both BMAL1 and PER2 exhibited antiphasic unimodal expression patterns, which were not correlated with adrenaline and noradrenaline levels. REV-ERBα expression varied, and no correlations were found between dopamine levels and clock gene expression in any group. We concluded that catecholamine levels are decreased in AIHD and raised in AMI as a function of BMAL1 expression and that BMAL1 and PER2 modulate and suppress catecholamine levels respectively.
Previous in vitro studies of alkali-treated titanium have shown that titanium with nanonetwork structures (TNS) implants have good osteogenic induction ability and superior surface properties. Here, we aimed to develop an implanting system with superior biological properties on the basis of previous in vitro experiments, determine the biological properties of TNS implants in animal experiments, and provide a basis for future clinical use of TNS implants by dentists. In this experiment, titanium discs and screws were soaked with alkali treatment and then analyzed by scanning electron microscopy, X-ray photoelectron spectrometry, scanning probe microscopy, and other methods. Additionally, a rat femoral implant model was established, and specimens were removed at 4 and 8 weeks after implantation and analyzed by micro-computed tomography (CT). After three-dimensional reconstruction of CT images, the bone volume fraction, trabecular number, trabecular separation, and trabecular thickness were analyzed. The experimental results showed that the surfaces of implants after alkali treatment exhibited a uniform three-dimensional nanonetwork structure, indicating that preparation of the TNS implant was successful. In general, TNS implants showed stronger osseointegration than pure titanium implants and were more suitable for oral clinical applications. Thus, these TNS implants may have applications as an implantation material for in clinical dentistry and orthopedics.
Research related to tooth size, tooth size discrepancy and relationship with BMI in transgender population is yet to be explored in dentistry. The purpose of this study is to establish normative data on mesiodistal width dimensions associated with BMI and tooth size discrepancy in transgender population. The data were derived from dental casts of 151 transgender individuals (75 transgender male, 76 transgender female; age group 18-30). Data were analysed using independent t-test and ANOVA. The mean and standard deviation were calculated for individual tooth size, Bolton’s overall and anterior ratios, and BMI separately for transgender males and females. The mesiodistal widths of the maxillary teeth showed higher variability than the mandibular teeth and the mean value was higher in transgender females than in males and revealed statistically significant differences. Bolton’s anterior ratios were found to be 78.05 (±3.67) for male and 78.90 (±4.12) for female. The mean of Bolton’s overall tooth ratio for male 91.03(±3.66) and for women was 91.46(±3.91) with no significant differences (p >0.05). No significant differences between BMI and mesiodistal tooth dimensions except for the left first molar tooth in mandible and left lateral incisor tooth in maxilla between overweight and underweight groups (p<0.05). These findings indicate that population-specific standards are necessary for clinical assessments and for several dental treatment purposes. Moreover, it is appropriate to use transgender norms in a regular dental practice for transgender individuals.
To determine the prevalence of incidental maxillary sinus findings and assess their relationships with age and gender. CBCT scans of 412 patients, comprising of 824 maxillary sinuses were evaluated. The maxillary sinuses were observed for increased mucosal thickening, polypoidal-mucosal thickening, opacification and other pathological changes. Correlations of these pathologic findings with age and gender were analyzed. The incidence of the pathological findings in maxillary sinuses observed was 30.1%. The most common abnormality observed as mucosal thickening followed by opacification. No significant correlation was observed between genders and different age groups. Based on the observations of the present study, it can be concluded that the prevalence of incidental maxillary sinus abnormalities in Saudi Arabian observed on CBCT is considerably high.
Hamid Hammad Enezei, Azlina Ahmad, Mohd Fadhli Khamis, Junji Suzuki, Yoshihiko Sugita, Hatsuhiko Maeda, Saaid Alshehadat, Noor Hayati Abdul Razak, Salah Khalaf Abbas, Ali Al Qabbani, Mohammad Khursheed Alam
To study the effectiveness of vascular endothelial growth factor (VEGF) added with biphasic calcium phosphate (BCP) on the expression of osteogenesis and angiogenesis-related gene in dental stem cells (DSCs). The cells were treated with three different modalities; BCP group, VEGF group, and VEGF-added-BCP. The optimal BCP and VEGF concentrations were determined. The cells were harvested at four different time intervals (day 3, day 7, day 10 and day 14) and were subjected to RNA isolation. Osteogenesis and angiogenesis-regulated genes was amplified using reverse transcriptase-PCR (RT-PCR). The RT-PCR products were then electrophoresed. The gel images were captured using Image Analyser AlphaEaseFC™. Angiogenesis and osteogenesis genes were clearly expressed in DSCs in response to treatments with 75mg/ml BCP and 5ng/ml VEGF. Angiogenesis gene VEGF was highly expressed by VEGF treatment group but showed some changes when added with BCP. Osteogenesis genes (BMP-2 and OPN) were positively affected by both BCP and VEGF. Some genes were expressed at an earlier time interval compared to the other genes depending on the type of treatments. BCP treatment induced high expression of initial-regulated osteogenesis genes (BMP-2 and OPN). Combination of BCP and VEGF modality on DSCs was suggested to initiate osteogenesis and angiogenesis-related gene expressions earlier than the other modalities. In our design, uncontrolled release of VEGF protein showed inhibition of BMP-2 at mRNA level in VEGF-BCP combined group.
The present study aimed to examine various factors affecting the bone mass of female university students. An ultrasound bone assessment device was used to measure the bone mass of the right calcaneal (heel) bone of 285 female university students. The subjects were asked to complete a questionnaire on the type and amount of time they spent practicing sports while attending elementary, junior, and senior high school and university as well as on milk and natto (fermented soybean) consumption and age at menarche to determine their associations with bone mass. Furthermore, the relationship between sports experience, intensity, and history of the subjects to bone mass was examined. We classified sports into high- and low-impact groups according to the type of sport played to examine the effects of impact on bone mass. We found the strongest correlation between bone mass and the amount of time spent practicing sports while attending senior high school. No correlation was found between bone mass and age at menarche and milk or natto consumption. From the relationship between sports experience and bone mass, we found that bone mass was significantly higher in the group with sports experience while attending junior and senior high school and university. In the assessment of sports intensity and bone mass, we found a significantly higher bone mass in those who played high-impact sports than in those who played low-impact sports. We also examined the effects of continued practice of sports on bone mass and found that more sports experience had a greater effect of increasing bone mass. Exercising while attending junior and senior high school had the highest influence on bone mass, which suggests that the long-term, continued practice of high-impact sports during this period allows a high bone mass to be obtained.
The surgical treatment of oral cancers can lead to continuity defects of the mandible. However, microvascularized free-tissue transfer has several limitations, including issues with morbidity of the donor site, complications and a poorly fitted bone geometry. Thus, non-vascularized iliac crest bone grafting, an established conventional technique, remains a feasible alternative for the reconstruction of mandibular continuity defects following advanced oral cancer resection. The purpose of this study was to retrospectively evaluate treatment outcomes using computer-assisted secondary reconstruction of mandibular continuity defects through non-vascularized iliac crest block grafts over a 5-year period and to explore clinical limitations. A total of 11 consecutive advanced oral cancer patients (6 males and 5 females; mean age, 66.6 years) were included in this study. Participants that received computer-assisted secondary non-vascularized iliac crest bone grafts following advanced oral cancer resection with reconstruction plates ± adjuvant chemoradiotherapy or radiotherapy were examined at least 1 year after the mandibular reconstructions. Patient records, as well as radiological and surgical data, were analyzed. Average cancer follow-up time was 18.0 months, and patients that underwent secondary functional and esthetic reconstruction had an average mandibular defect length of 65.5 mm. Complete bone healing was observed in all patients. However, four patients experienced wound dehiscence and surgical site infection, which required local management for complete wound healing. Adjuvant radiotherapy played a significant role (p < 0.05) in reconstruction site morbidity. In addition, eight patients (72.7%) received subsequent dental implants for oral functional rehabilitation. Our results suggest that non-vascularized iliac crest bone grafts are a reliable treatment option for secondary reconstruction of mandibular continuity defects up to a moderate length in oral cancer patients. However, radiotherapy may confound postoperative complications. Limitations of this technique include that the mandibular defect may be lateral and an extraoral approach is required.
Artificial bone has been applied to reconstruct bone defects. However, few reports have evaluated implant stability or implant placement after grafting block-type artificial bone. Interconnected porous hydroxyapatite (IP-CHA) has the superior advantage of osteoconduction ability because of porous and interconnected structure. The purpose of this study was to evaluate the stability of implants placed in bone reconstructed with an IP-CHA block. IP-CHA cylinders (D; 6.0 mm, H; 12.0 mm) were grafted into bone sockets in the right femurs of three male dogs. After 3 months, an implant was placed into a socket that was prepared in the central portion of the grafted IP-CHA on the right side, then implants were placed in the sockets (test-group). Simultaneously, an implant was placed into the parent bone of the left femur (control-group). The implant stability quotient (ISQ) was measured immediately after placement. Twelve weeks after implant placement, ISQ and removal torque (RT) measurements were performed to assess implant stabilities. ISQ values in the test-group after 12 weeks were significantly higher than those at the time of placement in the test and control groups (P<0.05). RT was not significantly different between bone sites reconstructed with IP-CHA and parent bone sites. At sites reconstructed with IP-CHA, bone formation was detected around the implant socket. The data indicate that favorable implant stability was achieved at sites reconstructed using an IP-CHA as well as at control. These results showed IP-CHA might be a useful type of artificial bone for preliminary bone reconstruction in implant therapy.
Eusthenopteron come under the rhipidistians. Little information is available regarding the ultrastructure and properties of tooth in Eusthenopteron. The purpose of the present study is to examine the nature of apatite crystals in the tooth of Eusthenopteron. Backscattered electron image of SEM revealed the tooth consisted of two layers, tentatively named as the bright surface layer and the dark inner dentin layer, respectively. The surface layer was more calcified than the inner dentin layer. The incremental lines were not observed in the surface layer. Narrow dentinal tubules were confirmed in the inner dentin layer. TEM study demonstrated the crystals of surface layer were not bearing the central dark lines (CDL-free type) in its structures. By contrast, the crystals of the inner dentin layer possessed the central dark lines (CDL-bearing type). X-ray diffraction analysis suggested that the crystal was fluorapatite in the surface layer, and a mixture of hydroxyapatite and fluorapatite in the inner dentin layer. The presence of fluorapatite in the dentin was estimated to be the influence of the fossilization. Using EPMA, F, Al, Si, Ca, and P were detected in the surface layer, and F, Na Mg, Si, Ca, and P were detected in dentin layer. The weight % F of the surface layer was 3.07, and 3.35 in the inner dentin layer. Raman spectrum analysis demonstrated that the phosphate peaks of 965 cm-1 assigned for hydroxyapatite in the inner dentin layer and 967 cm-1 assigned for fluorapatite in the surface layer were detected, respectively. Taking the crystallographic viewpoint and histological feature into consideration, the surface layer was regarded as enameloid and the inner dentin layer was orthodentin including plicidentin.
Traditional antiepileptic drugs (AEDs) such as phenytoin, decrease bone mineral density (BMD) and increase the risk of bone fracture in patients with epilepsy. In this study, we examined the effects of perampanel, a novel antiepileptic drug, on bone metabolism by bone histomorphometry. Following daily oral administration of either phenytoin (30 mg/kg) or perampanel (3.0 mg/kg) for 6 weeks, we performed bone histomorphometric analysis at the proximal tibial metaphysis of 6-week-old male C57BL/6 mice. A significant decrease in bone structure parameters such as the trabecular bone volume, trabecular thickness, and trabecular number was observed in the phenytoin group. These deteriorations of bone structure due to the administration of phenytoin were accompanied by a significant increase in the eroded surface per bone surface (ES/BS) and osteoclast number per bone surface (N.Oc/BS). In contrast, no significant change in bone structure parameters was observed in the perampanel group. However, compared to that in the control group, a significant decrease in bone formation parameters such as the osteoblast surface and mineral apposition rate occurred, additionally the ES/BS and N.Oc/BS were significantly increased in the perampanel group. These findings of this study suggest that perampanel may suppress bone formation and enhance bone resorption. Perampanel-induced failure of bone remodeling may have an adverse effect on bone volume with further long-term use. In the future, it would be necessary to conduct research studies to elucidate the detailed mechanism underlying the bone remodeling effect of perampanel.
To evaluate the efficacy of percutaneous vertebroplasty (PVP) for malignant vertebral compression fractures with symptoms of neurological compression and the predictive factors for poor neurologic outcomes following PVP. Forty-three patients with malignant vertebral compression fractures and symptoms of neurological compression were treated with PVP, and were classified into two groups according to the American Spinal Injury Association (ASIA) impairment scale at the last follow-up. Data were collected, and the patients were followed up for more than three months after the procedure. Univariate and multivariate analyses were performed to evaluate predictive factors of poor neurological recovery. PVP were successful in all patients. Full recovery from (n = 2) or improvement of (n =16) neurological compression symptoms was achieved in 18 patients (Group A), and no improvement of neurological compression symptoms in 25 patients (Group B). Univariate analysis showed more PMMA leakage (p = 0.038) and less PMMA volume injection (p < 0.001) was associated with the poor neurological recovery, and multivariate analysis showed that less PMMA volume injection (p = 0.004) was an independent predictor of poor neurologic recovery. PVP should not be served as an effective treatment for malignant compression fractures with symptoms of neurological compression, and less PMMA volume injection was an independent predictor of a poor neurologic recovery.
The goal of investigation is to examine the histological response to recombinant human bone morphogenetic protein-2 (rhBMP-2)-loaded demineralized dentin matrices (DDMs) of different origins. The evaluation site is chosen between the cover screw and gingiva, as the poor blood supply allows it to simulate a heterotopic condition. We hypothesize that the antigenicity and immunogenicity of the carrier allogenic DDMs are low enough to maintain both the biocompatibility of the scaffold and the activity of the loaded rhBMP-2. Three patients undergoing simultaneous implant placement and receiving a different type of graft were included: allogenic DDM loaded with rhBMP-2(DDM/rhBMP-2), autogenous DDM/rhBMP-2 and autogenous DDM. Histological specimens were retrieved during the secondary surgery after 3–6 months. In histological examination, particles were encapsulated by dense fibrous tissue without any inflammatory cells. The capsule contained an increased number of cell layers in the DDM/rhBMP-2 (allogenic and autogenous) compared to autogenous DDM. Resorption activity was higher in autogenous DDM/rhBMP-2 than in allogenic DDM/rhBMP-2. Within the limitations of this report, results demonstrated the successful use of DDM as a potential rhBMP2 carrier. Further studies will be required to confirm the safety and effectiveness of autogenous and allogenic DDM/rhBMP-2.
Ameloblastic fibro-odontoma (AFO) is defined as a tumor with general characteristics of an ameloblastic fibroma along with the presence of enamel and dentine. AFO is a well-encapsulated, painless, slow-growing, and expanding tumor in young patients. Histologically, it has been classified as an ameloblastic fibroma or odontoma. In the 2017 new WHO classification of odontogenic tumor, AFO is described that they in most cases represent developmental stages of either complex or compound odontoma and that retaining them as separate entities would therefore be illogical. However, there is still considerable confusion concerning the nature and histology of AFO and the surgical therapy for this lesion. Here we present a case of maxillary AFO and review the relevant literature regarding the clinical and surgical features of this lesion.