Sr-Incorporated Bioactive Glass Remodels the Immunological Microenvironment by Enhancing the Mitochondrial Function of Macrophage via the PI3K/AKT/mTOR Signaling Pathway.

The repair of critical-sized bone defects continues to pose a challenge in clinics. Strontium (Sr), recognized for its function in bone metabolism regulation, has shown potential in bone repair. However, the underlying mechanism through which Sr2+ guided favorable osteogenesis by modulating macrophages remains unclear, limiting their application in the design of bone biomaterials. Herein, Sr-incorporated bioactive glass (SrBG) was synthesized for further investigation. The release of Sr ions enhanced the immunomodulatory properties and osteogenic potential by modulating the polarization of macrophages toward the M2 phenotype. In vivo, a 3D-printed SrBG scaffold was fabricated and showed consistently improved bone regeneration by creating a prohealing immunological microenvironment. RNA sequencing was performed to explore the underlying mechanisms. It was found that Sr ions might enhance the mitochondrial function of macrophage by activating PI3K/AKT/mTOR signaling, thereby favoring osteogenesis. Our findings demonstrate the relationship between the immunomodulatory role of Sr ions and the mitochondrial function of macrophages. By focusing on the mitochondrial function of macrophages, Sr2+-mediated immunomodulation sheds light on the future design of biomaterials for tissue regenerative engineering.

Change in oral health-related behaviours of children before and after dental treatments under general anaesthesia.

This study evaluated the behavioural changes pertaining to children's oral health before and after the dental general anaesthesia (DGA), with particular focus on the factors associated with these changes. The records were collected for the children who received DGA from July 2015 to November 2016, and relevant questionnaires were obtained from their parents/guardians for the information prior to and after the DGA. The questionnaire included Early Childhood Oral Health Impact Scale (ECOHIS) and Dental Subscale of Children's Fear Survey Schedule (CFSS-DS) to investigate the changes in Oral Health-related Quality of Life (OHRQoL) and dental fear. The DGA impact on children's oral hygiene habits and oral health-related behaviours was assessed by analysing the data. The chi-square test and Mann-Whitney test were employed to evaluate the differences. Total of 141 patients (89 before DGA and 77 after DGA, 25 being common) participated in this study. There were 60 children below 5 years and 29 over 5 years before DGA, while 41 children below 5 years and 36 over 5 years after DGA. Most parents/guardians were educated above undergraduate level (59.6% before DGA, 55.8% after DGA). More children lived with grandparents (61.8% before DGA, 54.5% after DGA) than only with parents (20.2% before DGA, 26.0% after DGA). In total, 73.0% (65/89) children before DGA brushed teeth more than twice a day. This proportion increased to 90.9% after DGA (70/77, p = 0.03). The eating difficulty decreased after DGA according to ECOHIS (p = 0.01). CFSS-DS score also decreased after DGA (p < 0.05). After DGA, children's oral hygiene habits and oral health-related quality of life (OHRQoL) improved, children fear for dental treatment decreased, and parents became more attentive towards children oral health.

Comparison of wear and marginal fitness of 3D-printed deciduous molar crowns: An in vitro study.

This study aimed to evaluate the wear resistance of primary tooth enamel and 3 kinds of 3D printing materials and to compare the marginal fitness and internal suitability of prefabricated all-ceramic crowns, computer-aided design/manufacturing (CAD/CAM) all-ceramic crowns, and three 3D-printed deciduous molar crowns. Multifunctional friction wear testing machine was used to image the wear surface of the sample and calculate the maximum wear depth and volume loss value of each sample. The internal fit evaluation used the silicon replica method, The four points were measured using scanning electron microscopy (SEM). The obtained data were statistically analyzed using ANOVA and Tukey HSD-test with a fully randomized design (p<0.05). The results showed the wear resistance of E-Dent400 was better than that of PEEK and three different 3D printed materials have good wear resistance compared with the primary tooth enamel. The measured values at M1 and M4 of E-Dent400 were both the smallest.

Mussel-inspired cortical bone-adherent bioactive composite hydrogels promote bone augmentation through sequential regulation of endochondral ossification.

Endochondral ossification (ECO) plays an integral part in bone augmentation, which undergoes sequential processes including mesenchymal stem cells (MSC) condensation, chondrocyte differentiation, chondrocyte hypertrophy, and mineralized bone formation. Thus, accelerating these steps will speed up the osteogenesis process through ECO. Herein, inspired by the marine mussels' adhesive mechanism, a bioactive glass-dopamine (BG-Dopa) hydrogel was prepared by distributing the micro-nano BG to aldehyde modified hyaluronic acid with dopamine-modified gelatin. By in vitro and in vivo experiments, we confirm that after implanting in the bone augmentation position, the hydrogel can adhere to the cortical bone surface firmly without sliding. Moreover, the condensation and hypertrophy of stem cells were accelerated at the early stage of ECO. Whereafter, the osteogenic differentiation of the hypertrophic chondrocytes was promoted, which lead to accelerating the late stage of ECO process to achieve more bone augmentation. This experiment provides a new idea for the design of bone augmentation materials.

The design and clinical application of a new appliance to treat impacted maxillary central incisors.

Maxillary central incisor impaction is one of the most common types of dental anomalies in children. Treatment of impacted central incisors is complicated and challenging given the position of the impacted central incisors, root development, and the complexity of the crown eruption direction. This study aimed to describe the use of a new multifunctional appliance for the treatment of impacted maxillary central incisors. This article reports the use of a novel appliance for the treatment of impacted maxillary central incisors. We describe the cases of two young patients with labial horizontally impacted maxillary central incisors. Both patients were treated using this novel appliance. Therapeutic effects were evaluated by comparing the pretreatment results, posttreatment cone-beam computed tomography images, and posttreatment clinical examination results. At the end of the treatment period using the novel appliance, the impacted central incisors had successfully been properly aligned in the dental arch, and the tooth roots had not resorbed. Both patients exhibited good dental alignment, with restored function and acceptable aesthetics. This article demonstrates that the new appliance was comfortable, convenient, safe, and effective in the treatment of impacted maxillary central incisors and that its clinical use should be promoted in the future.

A bioactive glass functional hydrogel enhances bone augmentation via synergistic angiogenesis, self-swelling and osteogenesis.

Bone augmentation materials usually cannot provide enough new bone for dental implants due to the material degradation and mucosal pressure. The use of hydrogels with self-swelling properties may provide a higher bone augmentation, although swelling is generally considered to be a disadvantage in tissue engineering. Herein, a double-crosslinked gelatin-hyaluronic acid hydrogels (GH) with self-swelling properties were utilized. Meanwhile, niobium doped bioactive glasses (NbBG) was dispersed in the hydrogel network to prepare the GH-NbBG hydrogel. The composite hydrogel exhibited excellent biocompatibility and the addition of NbBG significantly improved the mechanical properties of the hydrogel. In vivo results found that GH-NbBG synergistically promoted angiogenesis and increased bone augmentation by self-swelling at the early stage of implantation. In addition, at the late stage after implantation, GH-NbBG significantly promoted new bone formation by activating RUNX2/Bglap signaling pathway. Therefore, this study reverses the self-swelling disadvantage of hydrogels into advantage and provides novel ideas for the application of hydrogels in bone augmentation.

Easily attainable and low immunogenic stem cells from exfoliated deciduous teeth enhanced the in vivo bone regeneration ability of gelatin/bioactive glass microsphere composite scaffolds.

Repair of critical-size bone defects remains a considerable challenge in the clinic. The most critical cause for incomplete healing is that osteoprogenitors cannot migrate to the central portion of the defects. Herein, stem cells from exfoliated deciduous teeth (SHED) with the properties of easy attainability and low immunogenicity were loaded into gelatin/bioactive glass (GEL/BGM) scaffolds to construct GEL/BGM + SHED engineering scaffolds. An in vitro study showed that BGM could augment the osteogenic differentiation of SHED by activating the AMPK signaling cascade, as confirmed by the elevated expression of osteogenic-related genes, and enhanced ALP activity and mineralization formation in SHED. After implantation in the critical bone defect model, GEL/BGM + SHED scaffolds exhibited low immunogenicity and significantly enhanced new bone formation in the center of the defect. These results indicated that GEL/BGM + SHED scaffolds present a new promising strategy for critical-size bone healing.

In vitro antibacterial effects of photodynamic therapy against Enterococcus faecalis in root canals of deciduous teeth.

OBJECTIVE: This study aimed at evaluating the in vitro antibacterial efficacy of photodynamic therapy (PDT) on planktonic E. faecalis and its biofilm in the root canal of infected deciduous teeth. METHODS: Forty root canals of maxillary deciduous anterior teeth were enlarged up to #35 K-file and inoculated with E. faecalis for 21 days. The root canals were randomly assigned into four groups (n = 10): The normal saline group (control), 1% NaClO group, PDT group, and the 1% NaClO + PDT group. Paper point samples were obtained at baseline (S1) and after treatment (S2). The colony-forming units (CFU) were counted, and the bacterial growth rate calculated. From each subgroup, 5 samples were randomly selected after treatment and a scanning laser confocal microscope (CLSM) used to determine the distribution of dead / living bacteria on the biofilm surface of each subgroup. A scanning electron microscope (SEM) was used to observe bacterial morphologies in the root canal walls of the remaining 5 samples in each subgroup. The Kruskal-Wallis test and Dunn test with boferroni adjustment were used to analyze the effect of the different treatment techniques on the E. faecalis in root canals. RESULTS: Compared to the saline group, PDT significantly reduced bacterial counts in the root canal (p < 0.05). The CFU counts were lowest (p < 0.05) in the 1% NaClO and in 1% NaClO + PDT groups. The rate of bacterial death on the surface of the biofilm in the PDT group was significantly increased after treatment (p < 0.05), and the rate of bacterial death was highest in 1%NaClO group and 1%NaClO + PDT group (p < 0.05). CONCLUSION: PDT has an antibacterial activity against E. faecalis in the root canal of deciduous teeth. Its activity against planktonic E. faecalis is better than the activity on the intact biofilm. The antibacterial activity of PDT on E. faecalis in root canals of deciduous teeth is lower compared to that of 1% NaClO.

Multipotent stem cells from apical pulp of human deciduous teeth with immature apex.

Isolation of high-quality human postnatal stem cells from accessible sources is an important goal for dental tissue engineering. Stem cells from developing organs are a better cell source but are hard to obtain. With extensive caries that are difficult to restore, the extracted deciduous tooth with an immature apex is a developing organ for investigation. In the present study, a cell population from the tip of apical pulp of human deciduous teeth with an immature apex was isolated and termed apical pulp-derived cells of deciduous teeth (De-APDCs). De-APDCs expressed STRO-1, CD44, CD90 and CD105 but not CD34 or CD45. Furthermore, De-APDCs demonstrated a significantly higher clonogenic and proliferative ability and osteo/dentinogenic differentiation capacity than dental pulp cells from exfoliated deciduous teeth (De-DPCs) (P < 0.05). Differentiation potential toward adipogenic, neurogenic and chondrogenic lineages was also observed in induced De-APDCs. In addition, after De-APDCs were seeded into hydroxyapatite/tricalcium phosphate (HA/TCP) scaffolds and transplanted into nude mice, they were able to regenerate dentin/pulp-like structures aligned with human odontoblast-like cells. In conclusion, De-APDCs, which are derived from a developing tissue, represent an accessible and prospective cell source for tooth regeneration.

[Role of autophagy in lipopolysaccharide-induced apoptosis of odontoblasts].

OBJECTIVE: To investigate the role of autophagy in lipopolysaccharide (LPS)-induced apoptosis of murine odontoblasts. METHODS: Murine odontoblasts (mDPC-23 cells) were treated with 5 µg/mL LPS for 6, 12 and 24 h, and the changes in cell viability was examined using CCK8 kit and cell apoptosis was detected by TUNEL staining. The changes in the protein levels of LC3, Beclin1, Atg5, AKT, p-AKT, mTOR and p-mTOR were detected using Western blotting. The effect of 3-MA treatment for 24 h on LPS-induced apoptosis of mDPC-23 cells was evaluated by detecting the expressions of apoptosis-related proteins caspase-3 and Bax using Western blotting. RESULTS: Stimulation with LPS for 6 and 12 h did not cause significant changes in the proliferation or apoptosis of mDPC-23 cells, but LPS treatment for 24 h significantly suppressed cell proliferation (P < 0.05) and promoted cell apoptosis as shown by TUNEL assay (P < 0.05). Stimulation with LPS for 24 significantly increased the expression levels of LC3, Beclin1 and Atg5, decreased the expressions of p-AKT and p-mTOR (P < 0.05), and obviously upregulated the expressions of caspase-3 and Bax (P < 0.05). Treatment with 3-MA markedly lowered caspase-3 and Bax protein expressions in LPS-stimulated cells (P < 0.05). CONCLUSIONS: LPS stimulation induces autophagy to promote apoptosis of mDPC-23 cells, and suppression of autophagy attenuates LPS-induced apoptosis. Autophagy may play an important role in the injury of inflamed pulp tissues.

Advances in the application of photodynamic therapy to root canal disinfection / 口腔疾病防治

@#In recent years, many researchers have devoted themselves to the application of photodynamic therapy (PDT) in root canal disinfection, as conventional root canal disinfection methods have failed to achieve the optimal effect. Some clinicians have also applied PDT to root canal disinfection. PDT is expected to have a better effect than traditional root canal disinfection. This paper reviews the research progress on the mechanism, effect, influencing factors and limitations of PDT in root canal disinfection. Current research suggests that differences in the type and status of the bacteria, photosensitizers, light sources, operating environment and methods all affect the efficacy of root canal disinfection of PDT. Most of the research into PDT for root canal disinfection finds that it is effective, nontoxic, advantageous to dental pulp regeneration and comfortable for the patient, as well as lacking an excitant; however, its bactericidal effect is inferior to that of sodium hypochlorite. At present, it cannot replace traditional chemical washing but is a promising auxiliary method. The design of the photosensitizer, the energy dose of the light source and the optimal irradiation time need to be determined by further experiments, and more clinical verification is needed before its application in root canal therapy.

Comparative analysis of transcriptomes between apical pulp-derived cells from deciduous teeth and permanent teeth or dental pulp cells from exfoliated deciduous teeth.

BACKGROUND: The present study aimed to explore the differences between apical pulp-derived cells of deciduous teeth (De-APDCs) and apical pulp-derived cells of permanent teeth (P-APDCs)/dental pulp cells from exfoliated deciduous teeth (De-DPCs). METHODS: Three types of cells (De-DPCs, P-APDCs and De-APDCs) were cultured by the tissue explant method. Transcriptome sequencing for the three types of cells was conducted and the differentially expressed genes (DEGs) between groups were selected. The potential biological functions and pathways enriched by the DEGs were analyzed. RESULTS: There were 35 up- and 21 down-regulated DEGs in P-APDC versus the De-APDC comparison group, and 328 up- and 976 down-regulated DEGs in De-APDC versus De-DPC. The DEGs in the P-APDC versus De-APDC group were significantly enriched in biological process terms associated with extracellular matrix organization, and regulation of cell proliferation and the pathway of cell adhesion molecules. Additionally, the DEGs between De-APDC and De-DPC were involved in functions related to extracellular matrix organization and the regulation of bone remodeling, as well as the pathway of extracellular matrix-receptor interaction. CONCLUSIONS: There were fewer differences between P-APDC and De-APDC compared to between De-APDC and De-DPC in view of the total number of DEGs. Differences in function existed relating to extracellular matrix organization among the three cells. P-APDCs and De-APDC had different functions on cell proliferation and adhesion. De-APDCs may also act as a unique stem cell resource for tissue engineering.

[Inhibition of autophagy suppresses osteogenic differentiation of stem cells from apical papilla].

OBJECTIVE: To investigate the effects of autophagy on osteogenic differentiation of stem cells from the apical papilla (SCAPs) in the presence of tumor necrosis factor-α (TNF-α) stimulation in vitro. METHODS: SCAPs treated with TNF-α (0, 5, and 10 ng/mL) with or without 5 mmol/L 3-MA were examined for the expression of autophagy marker LC3-Ⅱ using Western blotting. The cells were transfected with GFP-LC3 plasmid and fluorescence microscopy was used for quantitative analysis of intracellular GFP-LC3; AO staining was used to detect the acidic vesicles in the cells. The cell viability was assessed with CCK-8 assays and the cell apoptosis rate was analyzed using flow cytometry. The cells treated with TNF-α or with TNF-α and 3-MA were cultured in osteogenic differentiation medium for 3 to 14 days, and real- time PCR was used to detect the mRNA expressions of osteogenesis-related genes (ALP, BSP, and OCN) for evaluating the cell differentiation. RESULTS: TNF-α induced activation of autophagy in cultured SCAPs. Pharmacological inhibition of TNF-α-induced autophagy by 3-MA significantly decreased the cell viability and increased the apoptosis rate of SCAPs (P < 0.05). Compared with the cells treated with TNF-α alone, the cells treated with both TNF-α and 3-MA exhibited decreased expressions of the ALP and BSP mRNA on days 3, 7 and 14 during osteogenic induction (P < 0.05) and decreased expression of OCN mRNA on days 3 and 7 during the induction (P < 0.05). CONCLUSIONS: Autophagy may play an important role during the osteogenic differentiation of SCAPs in the presence of TNF-α stimulation.

The effects of leptin on osteogenesis/odontogenic related gene expression of human apical papillary stem cells / 口腔疾病防治

Objective@#To investigate the effects of leptin on the proliferation of stem cells from human stem cells from the apical papilla (hSCAPs) and the expression of osteogenic/dentinogenic genes in vitro to provide an experimental basis for the sustainable development of young permanent teeth. @* Methods @#The tissue block method was used to isolate and culture hSCAPs from the apical papilla of the immature third permanent molar. The expression of leptin and OBRb in hSCAPs was detected using immunocytofluorescence staining, western blotting and reverse transcription polymerase chain reaction (RT-PCR) analysis. The hSCAPs was treated with 0.1 μg/mL of leptin (0.1 μg/mL group) or 1.5 μg/mL of leptin (1.5 μg/mL group) at different time points. The control group was treated with alpha-MEM medium. Cell proliferation was measured using the CCK8 assay and cell cycle analysis. QRT-PCR was used to detect the expression of related osteoblast/odontogenic genes for alkaline phosphatase (ALP), dentin matrix protein -1 (DMP-1), dentin sialophosphoprotein (DSPP), and osteocalcin (OCN) mRNA. The differences between the treatment groups and the control group were analyzed statistically using one-way ANOVA followed by Bonferroni analysis.@*Results@#The expression of both leptin and OBRb were found in hSCAPs. Compared with the control group, the cell proliferation capacity and S phase cells in the treatment groups were higher than those in the control group, with the 1.5 μg /mL group displaying higher levels than 0.1 μg /mL group, and the treated hSCAPs demonstrated a higher proliferation rate and a higher expression of ALP, DSPP, and DMP-1 from day 3 to day 7, with the 1.5 μg /mL group displaying higher levels than 0.1 μg /mL group , and the difference was statistically significant (P < 0.05), at day 7. The treated hSCAPs demonstrated a lower expression of ALP, DSPP, and DMP-1. Compared with the control group, the treated hSCAPs demonstrated a higher expression of OCN from day 7 to day 14, with significantly higher expression in the 1.5 μg /mL group compared to the 0.1 μg /mL group.@*Conclusion@#Leptin may promote cell proliferation and upregulate the expression of relative osteogenic/dentinogenic genes.

Diagnosis and Treatment of Odontogenic Cutaneous Sinus Tracts in an 11-Year-Old Boy: A Case Report.

Odontogenic cutaneous sinus tracts (OCSTs) are generally primarily misdiagnosed and inappropriately treated by virtue of their rarity and the absence of dental symptoms. Accurate diagnosis and treatment and the elimination of the source of infection can reduce the incidence of complications and relieve the pain of the patient.In this case report, we present the case of an 11-year-old patient with an apparent abscess but an unobvious draining sinus tract in his left cheek. Intraorally, a glass-ionomer-cement filling on the occlusal surface of the left mandibular first molar (tooth 36) was noted. Radiographic examination revealed a radiopaque mass inside the crown and pulp chamber and an irregular, radiolucent periapical lesion surrounding the distal root apex. He was diagnosed with an OCTS secondary to a periapical abscess of tooth 36. Precise root canal therapy (RCT) and chronic granuloma debridement was performed; 6 months later, the abscess and sinus had healed completely, and the periapical lesion had resolved.Odontogenic cutaneous sinus tracts are uncommon in the clinic. This case report reminds us of the significance of OCSTs and provides some implications for their diagnosis and treatment.

Chondrogenic potential of stem cells from human exfoliated deciduous teeth in vitro and in vivo.

OBJECTIVE: The aim of this study was to investigate the chondrogenic potential of stem cells from human exfoliated teeth (SHED). MATERIALS AND METHODS: SHED cultures were isolated from human exfoliated deciduous teeth. Colony-forming capacity, odonto/osteogenic and adipogenic potential were measured. SHED were cultured for 2 weeks in chondrogenic differentiation medium containing dexamethasone, insulin, ascorbate phosphate, TGF-ß3 and bFGF. Toluidine blue staining and safranin O staining were used for chondrogenesis analysis. The related markers, type II collagen and aggrecan, were also investigated using immunohistochemistry. SHED were seeded onto the ß-TCP scaffolds and transplanted into the subcutaneous space on the back of nude mice. The transplants were recovered at 2, 4 and 8 weeks post-transplantation for analysis. RESULTS: SHED showed colony-forming capacity, odonto/osteogenic and adipogenic differentiation capacity. Chondrogenic differentiation was confirmed by toluidine blue staining, safranin O staining, type II collagen and aggrecan immunostaining. After in vivo transplantation, SHED recombined with ß-TCP scaffolds were able to generate new cartilage-like tissues. CONCLUSIONS: The findings demonstrate the chondrogenic differentiation capacity of SHED both in vitro and in vivo models, suggesting the potential of SHED in cartilage tissue engineering.

[Human stem cells from apical papilla can regenerate dentin-pulp complex].

OBJECTIVE: To regenerate dentin-pulp complex by tissue engineering with human stem cells from apical papilla cells (SCAP) as the seed cells. METHODS: SCAP was separated from from normal human impacted third molars with immature roots by outgrowth culture. The cells were then cultured in the differentiation medium for 3 weeks or in normal medium for 60 days, and analyzed for mineralization potential by Alizarin red staining. The osteo/odontogenic markers including alkaline phosphatase (ALP), bone sialoprotein (BSP), osteocalcin (OC) and dentin sialoprotein (DSP) were investigated by immunofluorescence staining and reverse transcription-polymerase chain reaction. The co-cultured mixture of SCAP and HA/TCP, or HA/TCP alone was implanted subcutaneously on the back of nude mice for 8 weeks, and the implants were collected and examined by HE and immunohistochemical staining. RESULTS: Round alizarin red-positive nodules formed in the isolated cells after cell culture in the differentiation medium for 3 weeks or in normal medium for 60 days with positive staining for osteo/odontogenic markers. SCAP with HA/TCP could regenerate pulp-dentin complex-like tissue in nude mice. The cells near the dentin-like tissue were positive for DSP. No mineral tissue was found in mice receiving HA/TCP implantation. CONCLUSIONS: SCAP may serve as a promising seed cell for dentin-pulp complex tissue engineering.

[Effect of revascularization treatment of immature permanent teeth with endodontic infection].

OBJECTIVE: To observe the effect of revascularization for treatment of immature teeth with endodontic infection mediated by calcium hydroxide. METHODS: Seventeen pediatric patients with endodontic infections of the permanent teeth were treated with routine root canal and pulp cavity irrigation and disinfection followed by application of calcium hydroxide paste to the root canal orifice to induce revascularization. Another 17 patients received conventional apexification procedures to serve as the control group. The patients were followed up to observe the therapeutic effect of the treatments. RESULTS: In the revascularization treatment group, 4 cases showed healed periapical lesions 6 to 18 months after the surgery with thickened root canal walls and closure of the apical foramen; in 10 cases, the periapical lesions healed 12 to 18 months postoperatively with lengthened root, thickened root canal wall, and narrowed apical foramen. One patient reported pain and swelling at 2 months, and 2 patients showed the formation of gum fistula and ceased development of the roots at 7 and 8 months. In the control group, the periapical lesions healed in 1 cases at 12 months postoperatively with apical foramen closure; in 11 cases, hard tissues formed in the root apex without obviously lengthened roots 6 to 8 months after the surgery; in 5 cases, no apical barrier formed even 12 to 18 months after the surgery. The overall effective rates were similar between the two groups (P>0.05). CONCLUSIONS: Revascularization by calcium hydroxide sealing can promote root development of immature permanent teeth with pulpitis or periradicular periodontitis.

Comparative analysis of in vitro periodontal characteristics of stem cells from apical papilla (SCAP) and periodontal ligament stem cells (PDLSCs).

OBJECTIVE: The aim of this study was to compare the in vitro periodontal properties of stem cells from apical papilla (SCAP) and periodontal ligament stem cells (PDLSCs). DESIGN: SCAP and PDLSCs cultures were established from normal human impacted third molars with immature roots. The cells were cultured in differentiation medium containing dexamethasone, ß-glycerophosphate and ascorbate phosphate for 3 weeks and in normal medium for as long as 60 days, and then were analysed for mineralisation potential. Cell proliferation, colony-forming capacity and periodontal ligament (PDL)-specific markers were also measured. The mineralisation markers, including alkaline phosphatase (ALP), bone sialoprotein (BSP) and osteocalcin (OC), were investigated by immunofluorescence staining and real-time polymerase chain reaction. The expression of PDL markers, including periostin and S100A4, was confirmed by reverse transcription polymerase chain reaction. RESULTS: SCAP showed a significantly higher proliferation rate and colony-forming capacity than PDLSCs. Both types of cells displayed mineralisation potential after induction and long-term culture. The SCAP, however, exhibited higher levels of ALP, BSP and OC expression than the PDLSCs. Like the PDLSCs, the SCAP exhibited periostin and S100A4 expression. CONCLUSIONS: Our study provides the first evidence showing that SCAP express periodontal properties in vitro. SCAP not only showed PDL-related markers, but also displayed a higher proliferation rate and a greater mineralisation capacity than those of PDLSCs. It might help understand the development of tooth root and periodontium. Furthermore, SCAP could be a promising candidate for periodontal tissue engineering.