Effect of icariin surface treatment on the resorption of denuded roots after replantation in rat.

AIM: Limiting the incidence of resorption associated with delayed replantation of avulsed teeth is critical for long-term tooth survival. In this study, we assessed whether icariin, a natural product with anti-osteoclastic properties, could reduce root resorption in a rat model of tooth replantation. METHODOLOGY: Cytocompatibility of icariin (10, 20, 40 and 80 µM) was evaluated by CCK-8 proliferation assay in vitro, and an osteoclastogenesis assay was performed to evaluate the effect of icariin on the differentiation of rat bone marrow macrophages and human peripheral blood monocytes into tartrate-resistant acid phosphatase-stained (TRAP+ ) multinucleated giant cells (MNGCs). Differentiation of human periodontal ligament stem cells (hPDLSCs) treated with icariin (10 µM) was also evaluated at 5, 10 and 21 days of osteogenic induction. The first maxillary molars of five-week-old male Sprague-Dawley rats were extracted, denuded of PDL, then treated either with neutralized collagen solution (Carrier control) or icariin in collagen (3 µg/µL) before replantation into their sockets. The animals were euthanized 2 weeks post-surgery for micro-computed tomography (micro-CT) imaging and histological analyses. RESULTS: Icariin was cytocompatible and significantly reduced the differentiation of TRAP+ MNGCs in a dose-dependent manner compared to the control. Moreover, icariin enhanced alkaline phosphatase activity, expression of osteogenic marker genes and proteins, and calcium deposition in hPDLSCs. Micro-CT imaging of the replanted samples demonstrated a significantly higher volume of remaining roots in the icariin-treated group than in the control group. Histological analysis revealed a marked number of resorptive lacunae with TRAP activity in the control group, whereas icariin-treated samples showed signs of functional healing and reduced osteoclastic activity. CONCLUSIONS: Icariin was biocompatible and demonstrated potent anti-osteoclastic and pro-osteogenic properties that reduced resorption and promoted functional healing of denuded roots in a rat maxillary first molar model of replantation. These findings indicate that root surface treatment with icariin may be a clinically relevant and practical method for improving the retention and survival of teeth with compromised PDL after delayed replantation following traumatic avulsion.

Biological Function and Potential Applications of Garcinol in Human Dental Pulp Stem Cells.

INTRODUCTION: The regeneration of pulp tissue is crucial for true regenerative endodontic treatment, which requires a reduction in osteogenic differentiation. Garcinol, a histone acetyltransferase inhibitor, is a natural regulator that is known to suppress the osteogenic differentiation of dental pulp stem cells. In this study, the inhibitory effect of garcinol on the osteogenic differentiation of human dental pulp stem cells (hDPSCs) was evaluated using three-dimensional culture under in vitro and in vivo conditions. METHODS: hDPSCs were obtained from caries-free third molars and cultured with 10 µM garcinol for 7 days in an ultra-low attachment plate. The cell stemness and expression of osteogenic differentiation-related genes were analyzed using reverse transcription-polymerase chain reaction and single-cell analysis. A transplantation experiment was performed in mice to investigate whether garcinol-treated hDPSCs showed restrained osteogenic differentiation. RESULTS: hDPSCs cultured in the U-shaped ultra-low attachment plate showed the highest expression of stemness-related genes. Garcinol-treated hDPSCs demonstrated downregulation of osteogenic differentiation, with lower expression of bone sialoprotein, which is related to bone formation, and higher expression of dentin sialophosphoprotein, which is related to dentin formation. However, the garcinol-treated hDPSCs did not show any alterations in their stemness. Consistent results were observed in the transplantation experiment in mice. CONCLUSIONS: Garcinol reduced the osteogenic differentiation of hDPSCs, which can contribute to true regenerative endodontic treatment.

Evaluation of the International Society for Cutaneous Lymphoma Algorithm for the Diagnosis of Early Mycosis Fungoides.

The International Society for Cutaneous Lymphoma (ISCL) proposes a diagnostic algorithm for early mycosis fungoides (MF) that includes clinical, histological, immunophenotypical, and molecular criteria. Here, we analyzed the immunologic markers and features of T-cell clonality in 38 early MF cases and 22 non-MF cases to validate the ISCL algorithm. We found that CD5 and CD7 expression differed significantly between early MF and non-MF cases, with epidermal discordance of CD7 expression more frequently identified in early MF. Notably, increasing the cut-off value for CD7 expression from 10% to 22.5% improved its sensitivity. Furthermore, TCR-γ and ß chain rearrangements were more frequently detected in early MF than in non-MF cases. Based on these findings, we propose CD5 and CD7 deficiency as mandatory immunopathologic criteria and PCR-based testing for TCR-γ and ß chains as required molecular/biologic criteria to improve the efficiency of early MF diagnosis using the ISCL algorithm.

The Effect of Mechanical Vibration on Osteogenesis of Periodontal Ligament Stem Cells.

INTRODUCTION: Appropriate occlusal forces can prevent ankylosis after tooth replantation or transplantation. However, the "proper occlusal forces" on periodontal ligament (PDL) healing have not yet been defined due to insufficient in vitro studies and uncertain in vitro models. Herein, we presented a mechanical vibration device as an in vitro model to determine such favorable occlusal forces. METHODS: Human periodontal ligament stem cells (hPDLSCs) were exposed to mechanical vibration force with 4 frequencies (30, 90, 150, and 210 rpm). Cell viability and the expression of osteogenic differentiation-related genes and proteins were tested in vitro. The calvarial transplantation experiment was performed to assess the bone formation ability of 150 rpm mechanical vibration stimulation (MVS). RESULTS: MVS at 150 and 210 rpm significantly reduced cell viability in the early stages. The 150-rpm MVS decreased osteogenic marker expression at the early time point (3 days) but had no harmful effects at the late time point (14 days). Furthermore, hPDLSC cell sheets treated with 150-rpm MVS had potential to decrease bone formation in rat calvarial defects serendipitously and facilitated functional PDL-like tissue formation. CONCLUSIONS: We found that MVS at a frequency of 150 rpm could provide a strategy for a transient reduction in the osteogenic potential of hPDLSCs and promote PDL-like tissue formation. Thus, 150-rpm MVS could be used as a controllable proper occlusal force to prevent ankylosis and promote PDL healing after tooth replantation or transplantation.

Antioxidant and Anti-Inflammatory Effect and Probiotic Properties of Lactic Acid Bacteria Isolated from Canine and Feline Feces.

Oxidative stress is a phenomenon caused by an imbalance between the production of reactive oxygen species and antioxidant defenses. It plays an important role in numerous disease states, including chronic kidney disease, neurological disorders, cardiovascular diseases, diabetes, and cancer. Lactic acid bacteria (LAB) are known to have prominent antioxidant properties. Therefore, this study aimed to measure the antioxidant activity and anti-inflammatory potential of LAB isolated from animals for the efficient use of probiotics with host specificity. Antioxidant activity measurements of sixteen strains revealed that ABTS radical scavenging activities ranged from 26.3 to 57.4%, and DPPH free radical scavenging activities ranged from 4.7 to 13.5%. Based on the antioxidant activity assessment, five strains (Enterococcus faecium MG9003(YH9003), Enterococcus faecium MG9007(YH9007), Lactobacillus reuteri MG9012(YH9012), Lactobacillus fermentum MG9014(YH9014), and Pediococcus pentosaceus MG9015(YH9015)) were selected with the consideration of fermentation productivity (>1 × 109 CFU/g). The selected strains exhibited nitric oxide inhibition and inhibited inducible nitric oxide synthase and cyclooxygenase expression. Furthermore, probiotic properties, including intestinal adhesion and stability, were identified. Our results show that the selected animal-derived strains can be effective probiotic candidates for potential effects on animal hosts.

Preserving the vitality of teeth adjacent to a large radicular cyst in periapical microsurgery: a case report with 4-year follow-up.

BACKGROUND: Radicular cysts may enlarge considerably, cause extensive bone destruction, and jeopardize the integrity of the associated vital teeth. The different treatment approaches are aimed mainly at eliminating the cystic epithelial membrane while reducing the risk of injury to vital structures. Contrary to other treatment modalities, preapical surgery offers an unequivocal single occasion resolution for the patient. However, it has been associated with higher risk of collateral damages. CASE PRESENTATION: A patient presented with a large radicular cyst originating from a maxillary lateral incisor. The adjacent central and canine teeth initially failed to exhibit responses to sensibility tests but showed signs of vitality. Microsurgical management was aimed at enucleating the cystic membrane while maintaining adjacent teeth vitality. Upon careful and controlled cyst enucleation under the dental operating microscope, the neurovascular bundle of one of the involved teeth was visualized and its integrity was maintained throughout the procedure. RESULTS: The procedure was successful and follow up recalls revealed recovery of normal sensibility of tooth 11 and 13 with complete bone regeneration around their apices. CONCLUSION: Within the limitation of the present case report, we demonstrated that complete excision of large periapical cyst can be performed without sacrificing the vitality of the adjacent teeth, by preserving the integrity of their neurovascular supply through controlled microsurgical enucleation, and by a potential apical vascular repair ensuing unintended injury. Diagnosing the pulp vitality of non-offending teeth whose apices protrude into the cystic lumen is a complex process and can be misleading. Pressure from the growing cyst can inhibit vital teeth responses to neural-based sensibility tests leading to false negative results. Thus, in such cases, the use of blood perfusion-based vitality testing is recommended for correct initial diagnosis.

Volume Percentage of Filling Voids in Root Canals Prepared by a Novel Nickel-Titanium Rotary System (TruNatomy) Using Two Different Obturation Techniques.

This study aimed to compare the volume percentage of filling voids in root canals prepared with a newly introduced rotary system, TruNatomy (Dentsply Maillefer), and obturated by the modified continuous wave (CW) or single cone (SC) filling technique. Plastic tooth models with four canals were enlarged by using TruNatomy files and randomly allocated into either the CW or SC group. The volume percentage of filling voids at 1-6 mm from the apex was analyzed by using microcomputed tomography; mean values were compared by using independent two-sample t-tests (p < 0.05). The mean volume percentages of the filling voids were 2.81 ± 1.11% and 1.77 ± 0.82% in the CW and SC groups, respectively. In the apical area (1-4 mm), volume percentages in the palatal were significantly different between the CW and SC groups; in the middle area (4-6 mm), volume percentages in the palatal and the second mesiobuccal canals were significantly different (p < 0.05). The SC group showed lower volume percentages of filling voids than the CW group. The canals prepared by the TruNatomy system can be obturated well by both the SC and CW techniques. The SC technique showed a lower number of voids, especially in the palatal canals.

A One-Year Radiographic Healing Assessment after Endodontic Microsurgery Using Cone-Beam Computed Tomographic Scans.

This study aimed to evaluate one-year radiographic healing after endodontic microsurgery using CBCT with modified PENN 3D criteria and to compare the outcome with results evaluated using Molven's criteria. A total of 107 teeth from 96 patients were evaluated one year after endodontic microsurgery by using CBCT scans with modified PENN 3D criteria and periapical radiographs with Molven's criteria. Both preoperative and postoperative lesion volumes were calculated using ITK-SNAP (free software). Radiographic healing assessment using periapical radiographs and CBCT images, and preoperative and postoperative lesion volume measurements were performed independently by two examiners. The assessment using Molven's criteria resulted in 75 complete healings, 18 incomplete healings, eight uncertain healings, and six unsatisfactory healings. Based on modified PENN 3D criteria, 64 teeth were categorized as complete healing, 29 teeth as limited healing, six teeth as uncertain healing, and eight teeth as unsatisfactory healing. With the one-year follow-up, CBCT scans showed a lower healing tendency than did periapical radiography. The volumes of apical radiolucency after the surgery were reduced by 77.7% on average at one-year follow up.

The application of "bone window technique" using piezoelectric saws and a CAD/CAM-guided surgical stent in endodontic microsurgery on a mandibular molar case.

Apical surgery for a mandibular molar is still challenging for many reasons. This report describes the applications of computer-guided cortical 'bone-window technique' using piezoelectric saws that prevented any nerve damage in performing endodontic microsurgery of a mandibular molar. A 49-year-old woman presented with gumboil on tooth #36 (previously endodontically treated tooth) and was diagnosed with chronic apical abscess. Periapical lesions were confirmed using cone-beam computed tomography (CBCT). Endodontic microsurgery for the mesial and distal roots of tooth #36 was planned. Following the transfer of data of the CBCT images and the scanned cast to an implant surgical planning program, data from both devices were merged. A surgical stent was designed, on the superimposed three-dimensional model, to guide the preparation of a cortical window on the buccal side of tooth #36. Endodontic microsurgery was performed with a printed surgical template. Minimal osteotomy was required and preservation of the buccal cortical plate rendered this endodontic surgery less traumatic. No postoperative complications such as mental nerve damage were reported. Window technique guided by a computer-aided design/computer-aided manufacture based surgical template can be considerably useful in endodontic microsurgery in complicated cases.

Stress Analyses of Retrograde Cavity Preparation Designs for Surgical Endodontics in the Mesial Root of the Mandibular Molar: A Finite Element Analysis-Part II.

INTRODUCTION: The aim of this study was to investigate the influence of apical filling material and the modification made to the apical preparation design in surgical endodontics on the areas of stress concentration in the mesial root of a mandibular molar using finite element analysis. METHODS: The filling material was injected under 2 conditions (ie, with or without mineral trioxide aggregate retrograde filling). The apical preparation design was modified by extending the preparation mesially while maintaining a similar prepared area. We contained the displacement of all the nodes at the base of the supporting bone and applied a force of 150 N to the vertical axis. We analyzed stress generation and concentrations numerically for all cavity design groups. RESULTS: In the presence of retrograde filling, the von Mises stress decreased gradually according to the enlargement of the prepared cavity in the subgroups. When the retrograde filling was absent, the von Mises stress increased as the prepared cavity enlarged. The modification of the apical preparation extending in the mesial direction showed a drastic decrease in stress concentration. CONCLUSIONS: Within the limitations of this study, it was advantageous to perform mesial retrograde preparation within the mesial root dentin to maintain a balanced root dentin on both sides of the apical preparation and create a low-stress field. The surgeon should be careful not to wash out or dislodge the retrograde filling material during obturation to avoid failure of surgery.

Effects of fast- and slow-setting calcium silicate-based root-end filling materials on the outcome of endodontic microsurgery: a retrospective study up to 6 years.

OBJECTIVES: The purpose of this retrospective study was to evaluate and compare the effects of fast- and slow-setting calcium silicate-based materials (CSMs) used for root-end filling on the outcome of endodontic microsurgery. MATERIALS AND METHODS: We searched a clinical database for patients who had received endodontic microsurgery between 2001 and 2016. Included cases were divided into two groups according to the type of CSM used for root-end filling: slow-setting CSM (SCSM) and fast-setting CSM (FCSM). The cases in two groups were subjected to 1:1 nearest neighbor propensity score matching for the following variables: age, sex, tooth type, quality of canal filling, lesion type, and postoperative restoration. For each matched case, the outcome was determined as success or failure according to clinical and radiographic evaluations performed at least 1 year after surgery. Multivariate logistic regression analysis was performed to identify prognostic factors and estimate their effects. RESULTS: In total, 304 cases of endodontic microsurgery (179 SCSM and 125 FCSM) were identified, and 1:1 propensity score matching finally included 122 cases from each group. After matching, all covariates were associated with an absolute standardized difference of < 0.1. The overall success rates were 85.2% and 93.4% for the SCSM and FCSM groups, respectively (p = 0.062). Age, tooth type, lesion type, and CSM type were significantly associated with the outcome of endodontic microsurgery (p < 0.05). CONCLUSIONS: Within the limitations, the outcome of endodontic microsurgery using FCSMs was comparable with that of SCSMs. The findings suggest that the type of CSM used for root-end filling, particularly in terms of the initial setting time, could affect the outcome of endodontic microsurgery. CLINICAL RELEVANCE: FCSMs could be considered for use as root-end filling materials in endodontic microsurgery, particularly in complicated clinical situations which require rapid initial setting of the materials.

Development of a mouse model for pulp-dentin complex regeneration research: a preliminary study.

OBJECTIVES: To achieve pulp-dentin complex regeneration with tissue engineering, treatment efficacies and safeties should be evaluated using in vivo orthotopic transplantation in a sufficient number of animals. Mice have been a species of choice in which to study stem cell biology in mammals. However, most pulp-dentin complex regeneration studies have used large animals because the mouse tooth is too small. The purpose of this study was to demonstrate the utility of the mouse tooth as a transplantation model for pulp-dentin complex regeneration research. MATERIALS AND METHODS: Experiments were performed using 7-week-old male Institute of Cancer Research (ICR) mice; a total of 35 mice had their pulp exposed, and 5 mice each were sacrificed at 1, 2, 4, 7, 9, 12 and 14 days after pulp exposure. After decalcification in 5% ethylenediaminetetraacetic acid, the samples were embedded and cut with a microtome and then stained with hematoxylin and eosin. Slides were observed under a high-magnification light microscope. RESULTS: Until 1 week postoperatively, the tissue below the pulp chamber orifice appeared normal. The remaining coronal portion of the pulp tissue was inflammatory and necrotic. After 1 week postoperatively, inflammation and necrosis were apparent in the root canals inferior to the orifices. The specimens obtained after experimental day 14 showed necrosis of all tissue in the root canals. CONCLUSIONS: This study could provide opportunities for researchers performing in vivo orthotopic transplantation experiments with mice.

Outcome of Endodontic Micro-resurgery: A Retrospective Study Based on Propensity Score-matched Survival Analysis.

INTRODUCTION: The purpose of this retrospective study was to evaluate and compare the outcome of endodontic micro-resurgery with that of primary endodontic microsurgery and determine prognostic factors affecting the outcome of micro-resurgery. METHODS: A clinical database was searched for endodontic microsurgery cases between 2001 and 2016. Nearest neighbor 2:1 propensity score matching for the following 5 variables was performed for cases of primary microsurgery and those of micro-resurgery: age, sex, tooth type, lesion type, and postoperative restoration. For the matched cases, the outcome was categorized as success or failure according to clinical and radiographic evaluations performed at least 1 year after surgery. Kaplan-Meier survival analysis and log-rank tests were performed to compare the outcome of primary microsurgery with that of micro-resurgery over time. For the micro-resurgery group, multivariate Cox proportional hazard regression analysis was performed to identify prognostic factors and estimate their effects. RESULTS: In total, 571 cases of endodontic microsurgery (498 primary microsurgery and 73 micro-resurgery cases) were identified, and 146 cases of primary microsurgery were matched to 73 cases of micro-resurgery through 2:1 propensity score matching. After matching, all covariates demonstrated an absolute standardized difference of <0.1. The estimated 5-year success rates were 91.6% and 87.6% for primary microsurgery and micro-resurgery, respectively (P = .594). The tooth type was found to be the only contributing factor for the outcome of micro-resurgery, with molars showing a higher probability of failure than anterior teeth (hazard ratio, 8.53; P = .002). CONCLUSIONS: Within the limitations, the findings of this study suggest that the outcome of endodontic micro-resurgery is comparable with that of primary endodontic microsurgery.

Evaluation of the Biodistribution of Human Dental Pulp Stem Cells Transplanted into Mice.

INTRODUCTION: Several studies have attempted to use human dental pulp stem cells (hDPSCs) for pulp-dentin complex regeneration in vitro. However, the safety of such applications should be first evaluated in vivo before their use in clinical trials. The purpose of this study was to investigate the in vivo fate of intrapulpally transplanted hDPSCs. METHODS: hDPSCs were isolated and cultured from impacted third molars. In vivo experiments were performed using 7-week-old male BALB/c nude mice. Under deep anesthesia, 1 × 105 hDPSCs were transplanted in mice via the tail vein for intravenous injection or into the pulp chamber for intrapulpal transplantation. A total of 56 mice, 28 per group, were used. Mice were sacrificed at different time points, and the numbers of hDPSCs in the organs were analyzed quantitatively. In addition, qualitative analysis was performed to detect intrapulpally transplanted hDPSCs. RESULTS: Intravenously injected hDPSCs were mostly distributed to the lungs and rarely detected in other organs at all observed time points. The hDPSCs transplanted into the pulp chamber rarely migrated to other organs over time. CONCLUSIONS: These data indicate a differential distribution of transplanted hDPSCs between the intravenous and intrapulpal route and show the safety of pulpal transplantation of hDPSCs.

Computer-aided Design/Computer-aided Manufacturing-guided Endodontic Surgery: Guided Osteotomy and Apex Localization in a Mandibular Molar with a Thick Buccal Bone Plate.

A mandibular molar with a thick buccal bone plate is a challenging problem in endodontic surgery despite the increase in the success rate of endodontic surgery nowadays. This report describes the application of a surgical template to guide osteotomy and facilitate apex localization in a mandibular molar with a thick buccal bone plate. A 57-year-old woman visited the authors' clinic for pain in tooth 19 and was diagnosed with symptomatic apical periodontitis in this previously treated tooth. Nonsurgical retreatment was performed; however, 2 years later, the patient reported pain in the same tooth. A periapical lesion was confirmed using cone-beam computed tomographic (CBCT) imaging, and endodontic surgery on the mesial root of tooth 19 was planned. After CBCT imaging and cast scan data were transferred to implant surgical planning software, the data were superimposed. In the superimposed model, an anchor pin was designed to target the mesial root apex of tooth 19. The surgical template was then printed using a 3-dimensional printer. Endodontic microsurgery included application of this printed surgical template. A computer-aided design/computer-aided manufacturing (CAD/CAM)-guided surgical template minimized the extent of osteotomy and enabled precise targeting of the apex in this case. There were no postoperative complications. A CAD/CAM-guided surgical template is useful in endodontic surgery for complicated cases.

The Influence of an Isthmus on the Outcomes of Surgically Treated Molars: A Retrospective Study.

INTRODUCTION: The purpose of this study was to investigate the effects of an isthmus on the success rate of surgically treated molars. METHODS: The study included 106 maxillary and mandibular first molars with endodontic lesions limited to the periapical area. Endodontic microsurgical procedures were performed according to the Yonsei protocol reported in a previous study. When an isthmus was observed after a high-magnification inspection, it was included in the retrograde preparation design. When an isthmus was not observed, only the main root canal space was prepared. The patients were followed up periodically every year after treatment. Success was defined as the absence of clinical signs and symptoms and radiographic evidence of complete or incomplete healing. RESULTS: Of the 106 teeth included in the study, 72 teeth had an isthmus, and 34 did not. Kaplan-Meier analysis revealed that the cumulative survival rate after surgery was 61.5% and 87.4% for 4 years when an isthmus was present and absent, respectively. A multivariate Cox proportional hazards regression analysis showed that the adjusted hazard ratio for failure was 6.01 times higher for the isthmus-present teeth than for the isthmus-absent teeth (P < .05). CONCLUSIONS: In this study, the success rate for endodontic microsurgery on isthmus-absent teeth was higher than that for isthmus-present teeth. Considering the success rate and potential risk of weakening the root after preparation, the techniques of isthmus preparation need to be improved.

A Randomized Controlled Study of Mineral Trioxide Aggregate and Super Ethoxybenzoic Acid as Root-end Filling Materials in Endodontic Microsurgery: Long-term Outcomes.

INTRODUCTION: The purpose of the present study was to evaluate the long-term clinical outcome of endodontic microsurgery when mineral trioxide aggregate (MTA) and super ethoxybenzoic acid (Super EBA; Harry J. Bosworth, Skokie, IL) were used as root-end filling materials. Additionally, this study aimed to compare the clinical outcome of endodontic microsurgery at the 1-year follow-up with that at the 4-year follow-up. METHODS: Two hundred sixty teeth were randomly assigned to either the MTA or Super EBA group in equal numbers using the minimization method. Endodontic microsurgery was performed according to the Yonsei protocol. The previous study of 192 teeth examined at the 1-year follow-up revealed a success rate of 95.6% for MTA and 93.1% for Super EBA. Patients were recalled 4 years after surgery, and treated teeth were classified as successes or failures with Molven's criteria. The Pearson chi-square test and the McNemar test were conducted to analyze and compare the success rates. RESULTS: A total of 182 teeth were examined at the 4-year follow-up. The success rate was 91.6% for MTA and 89.9% for Super EBA. Statistical analysis of the success rate did not show any significant difference between the 2 materials (P = .8). The overall success rate at the 4-year follow-up was 89.5%, which was slightly lower compared with 94.3% at the 1-year follow-up. However, there was no significant difference between the follow-up periods (P = .063). CONCLUSIONS: This study identified no significant difference in the 4-year success rates of MTA and Super EBA as root-end filling materials in endodontic microsurgery. Additionally, compared with short-term outcomes, long-term follow-up outcomes were not significantly different.

In Vivo Experiments with Dental Pulp Stem Cells for Pulp-Dentin Complex Regeneration.

In recent years, many studies have examined the pulp-dentin complex regeneration with DPSCs. While it is important to perform research on cells, scaffolds, and growth factors, it is also critical to develop animal models for preclinical trials. The development of a reproducible animal model of transplantation is essential for obtaining precise and accurate data in vivo. The efficacy of pulp regeneration should be assessed qualitatively and quantitatively using animal models. This review article sought to introduce in vivo experiments that have evaluated the potential of dental pulp stem cells for pulp-dentin complex regeneration. According to a review of various researches about DPSCs, the majority of studies have used subcutaneous mouse and dog teeth for animal models. There is no way to know which animal model will reproduce the clinical environment. If an animal model is developed which is easier to use and is useful in more situations than the currently popular models, it will be a substantial aid to studies examining pulp-dentin complex regeneration.

Vertical Bone Growth after Autotransplantation of Mature Third Molars: 2 Case Reports with Long-term Follow-up.

Tooth autotransplantation is a viable treatment option for tooth replacement when a suitable donor tooth is available. These case reports described significant vertical bone growth after autotransplantation of a mature third molar. The left mandible third molars (n = 2) were transplanted to the missing tooth in the left mandible. The patient follow-up period was 10 years after transplantation. Clinical examination revealed no mobility of the transplanted tooth. Radiographic examination indicated that bone regeneration occurred around the transplanted tooth. Vertical bone growth was observed in the cervical area of the root surface and the recipient bone. In autotransplantation of mature teeth, long-term follow-up results indicate that vertical bone growth can be expected if viability of the periodontal ligament cells is maintained.

Tetraiodothyroacetic acid-tagged liposomes for enhanced delivery of anticancer drug to tumor tissue via integrin receptor.

Nanoparticles have demonstrated potential for promoting drug delivery to tumor sites and enhancing uptake. Here, we report tetraiodothyroacetic acid (tetrac) as a promising new targeting moiety for delivery of anticancer drugs to tumor tissues. Tetrac, an antagonist that blocks the binding of thyroid hormone to integrin αvß3, was covalently linked to the activated end of pegylated lipid and used to formulate tetrac-tagged pegylated liposomes (TPL). After incubating with TPL for 9h, cellular accumulation efficiency into A375 human melanoma cells, which express integrin αvß3 at high density, was high (98.5%± 0.5% of cells), whereas that in KB cells, which express integrin at a very low density, was much lower (35.1%± 4.5%). Molecular imaging revealed that TPL preferentially distributed to tumor tissues after systemic administration in mice, where as non-targeting pegylated liposomes were distributed to tumors at background levels. Treatment with the alkyl lysophospholipid anticancer drug edelfosine, encapsulated in TPL, significantly reduced the survival of A375 tumor cells compared to cells treated with edelfosine in pegylated liposomes or with lysophosphatidylcholine encapsulated in TPL. Moreover, intravenous administration of edelfosine in TPL significantly reduced the growth of tumors and prolonged the survival of A375-xenografted mice, providing 100% protection for up to 50 days and some protection until 66 days (0% survival endpoint). In contrast, no untreated mice or mice treated with edelfosine-loaded pegylated liposomes survived up to 50 or 48 days, respectively, after tumor inoculation. These results suggest the potential of tetrac as a new ligand moiety for enhancing the delivery of anticancer drug-loaded nanoparticles to tumors and enhancing the therapeutic efficacy of encapsulated anticancer drugs.