Selenium-modified calcium phosphate cement can accelerate bone regeneration of osteoporotic bone defect.

OBJECTIVE: The purpose is to observe whether local administration with selenium (Se) can enhance the efficacy of calcium phosphate cement (CPC) in the treatment of osteoporotic bone defects. METHODS: Thirty ovariectomized (OVX) rats with two defects were generated and randomly allocated into the following graft study groups: (1) OVX group (n = 10), (2) CPC group (n = 10); and (3) Se-CPC group (n = 10). Then, these selenium-modified calcium phosphate cement (Se-CPC) scaffolds were implanted into the femoral epiphysis bone defect model of OVX rats for 12 weeks. Micro-CT, history, western blot and reverse transcription-quantitative polymerase chain reaction (RT-qPCR) analysis were used to observe the therapeutic effect and to explore the possible mechanism. RESULT: Micro-CT and histological analysis evaluation showed that the Se-CPC group presented the strongest effect on bone regeneration and bone mineralization when compared with the CPC group and the OVX group. Protein expressions showed that the oxidative stress protein expressions, such as SOD2 and GPX1 of the Se-CPC group, are significantly higher than those of the OVX group and the CPC group, while Se-CPC remarkably reduced the expression of CAT. RT-qPCR analysis showed that the Se-CPC group displayed more OPG than the OVX and CPC groups (p < 0.05), while Se-CPC exhibited less RANKL than the OVX and CPC groups (p < 0.05). CONCLUSION: Our current study demonstrated that Se-CPC is a scheme for rapid repair of femoral condylar defects, and these effects may be achieved by inhibiting local oxidative stress and through OPG/RANKL signaling pathway.

Effects of low-temperature degradation on the surface roughness of yttria-stabilized tetragonal zirconia polycrystal ceramics: A systematic review and meta-analysis.

STATEMENT OF PROBLEM: A wide range of yttria-stabilized tetragonal zirconia polycrystal (Y-TZP) ceramics have been applied for dental restorations. However, whether hydrothermal aging affects the surface roughness of Y-TZP is unknown. PURPOSE: The purpose of this systematic review and meta-analysis was to evaluate the effects of low-temperature degradation (LTD) on the surface roughness of Y-TZP ceramics. MATERIAL AND METHODS: This report follows the Preferred Reporting Items for Systematic Reviews and Qualitative Analyses statement. The literature search was conducted with Medline through the PubMed, Web of Science, and Cochrane Library with no publication year limits. The screening and quality assessment were performed by 2 independent reviewers. The studies comparing the surface roughness of Y-TZP ceramics after LTD by using steam autoclave aging were included in the meta-analysis. Meta-analyses were conducted with a random-effects model (α=.05) by using Review Manager Software (Cochrane Collaboration). RESULTS: Of the 203 potentially relevant studies, 32 full texts were assessed for eligibility. A total of 17 articles were included in the systematic review, and 15 were included in the qualitative analyses. The results showed no significant difference in the arithmetic average height (Ra) values between the nonaged and aged Y-TZP (P=.670; mean difference=0.01; 95% confidence interval=-0.03 to 0.05). Subgroup analyses revealed that the aging duration (P=.003) and specimen preparation (P=.010) contributed significantly to the changes in the surface roughness of the Y-TZP ceramics. CONCLUSIONS: Although LTD was found to have no significant effects on the surface roughness of Y-TZP ceramics, the effects of LTD depended on the duration of the steam autoclave process and the specimen preparation.

Effects of platelet concentrates on implant stability and marginal bone loss: a systematic review and meta-analysis.

BACKGROUND: Osseointegration is essential for the success and stability of implants. Platelet concentrates were reported to enhance osseointegration and improve implant stability. The purpose of this review is to systematically analyze the effects of platelet concentrates on implant stability and marginal bone loss. METHODS: Two researchers independently performed searches in the following databases (last searched on 21 July 2021): MEDLINE (PubMed), Cochrane Library, EMBASE, and Web of Science. In addition, a manual search was carried out on references of relevant reviews and initially included studies. All randomized controlled trials (RCTs) and controlled clinical trials (CCTs) on the application of platelet concentrates in the implant surgery procedure were included. The risk of bias of RCTs and CCTs were assessed with a revised Cochrane risk of bias tool for randomized trials (RoB 2.0) and the risk of bias in non-randomized studies-of interventions (ROBINS-I) tool, respectively. Meta-analyses on implant stability and marginal bone loss were conducted. Researchers used mean difference or standardized mean difference as the effect size and calculated the 95% confidence interval. In addition, subgroup analysis was performed based on the following factors: type of platelet concentrates, method of application, and study design. RESULTS: Fourteen studies with 284 participants and 588 implants were included in the final analysis. 11 studies reported implant stability and 5 studies reported marginal bone level or marginal bone loss. 3 studies had high risk of bias. The meta-analysis results showed that platelet concentrates can significantly increase implant stability at 1 week (6 studies, 302 implants, MD 4.26, 95% CI 2.03-6.49, P < 0.001) and 4 weeks (8 studies, 373 implants, MD 0.67, 95% CI 0.46-0.88, P < 0.001) after insertion, significantly reduced marginal bone loss at 3 months after insertion (4 studies, 95 implants, mesial: MD - 0.33, 95% CI - 0.46 to - 0.20, P < 0.001; distal: MD - 0.38, 95% CI - 0.54 to - 0.22, P < 0.001). However, the improvement of implant stability at 12 weeks after insertion was limited (P = 0.10). Subgroup analysis showed that PRP did not significantly improve implant stability at 1 week and 4 weeks after insertion (P = 0.38, P = 0.17). Platelet concentrates only placed in the implant sites did not significantly improve implant stability at 1 week after insertion (P = 0.20). CONCLUSIONS: Platelet concentrates can significantly improve implant stability and reduce marginal bone loss in the short term. Large-scale studies with long follow-up periods are required to explore their long-term effects and compare effects of different types. TRIAL REGISTRATION: This study was registered on PROSPERO, with the Registration Number being CRD42021270214.

Effects of adjunctive probiotic L. reuteri lozenges on S/RSD outcomes at molar sites with deep pockets.

AIM: To evaluate effects of probiotic Lactobacillus reuteri (L. reuteri) lozenges as an S/RSD adjunct on site-level changes at molars with deep pockets. MATERIALS AND METHODS: 447 molar sites with pockets ≥ 5 mm from a previous randomized clinical trial of adjunctive L. reuteri lozenges for 28 days were analyzed. Multilevel mixed-effect models (MLM) were constructed to analyze site-level outcomes "change in CAL" and "pocket closure" (residual PPD < 5 mm) in placebo and probiotic groups at 90 and 180 days. Possible patient-, tooth-, and site-level predictors were analyzed as fixed-effects. RESULTS: Estimated change in CAL in probiotic (90 day: 0.87 mm, 180 day: 0.68 mm) was greater than placebo treated molar sites (90 day: 0.73 mm, 180 day: 0.66 mm) and the relative risk (RR) of pocket closure in the probiotic group (90 day: 1.7, 180 day: 1.6) was higher as compared to placebo. Furcation involvement and BOP at site predicted significantly worse treatment outcomes. CONCLUSION: As compared to S/RSD with placebo, a 28-day course of adjunctive probiotic L. reuteri lozenges improved CAL change at molar sites with ≥ 5 mm deep pockets and conferred a higher probability of shallow residual pocket depth. Presence of furcation-involvement and bleeding on probing worsened treatment outcomes.

Minimally invasive procedures for deficient interdental papillae: A review.

OBJECTIVE: Deficient interdental papillae cause a series of problems, including food impaction, phonetic difficulties, and esthetic concerns. The purpose of this article is to provide valid clinical recommendations for clinicians to address these problems in a predictable and less invasive way. OVERVIEW: Numerous treatments are available for interdental papillae reconstruction, but most of them involve surgery and yield unpredictable outcomes. Minimally invasive treatments have the advantages of being effective, predictable, and involving only slight injury as compared to surgical treatments. We included 66 studies obtained after searching for relevant papers in PubMed and Web of Science. The etiology and classification of deficient interdental papillae are explained and minimally invasive procedures for deficient interdental papillae reconstruction are summarized. CONCLUSIONS: Minimally invasive procedures are promising ways to reconstruct deficient interdental papillae, and have the advantages of slight pain and rapid recovery. It should be noticed that some of the minimally invasive treatments still require further long-term observation to confirm their efficacy. CLINICAL SIGNIFICANCE: Familiarity with etiology and classification of deficient interdental papillae can help clinicians to choose the appropriate minimally invasive approach as well as help with case collection to enhance esthetics status in patients with deficient interdental papillae.

Local administration of aspirin with ß-tricalcium phosphate/poly-lactic-co-glycolic acid (ß-TCP/PLGA) could enhance osteoporotic bone regeneration.

Composite materials ß-tricalcium phosphate (ß-TCP) and poly-lactic-co-glycolic acid (PLGA) have achieved stable bone regeneration without cell transplantation in previous studies. Recent research shows that aspirin (ASP) has great potential in promoting bone regeneration. The objective of the present study was to incorporate PLGA into ß-TCP combined with a lower single-dose local administration of ASP to enhance its in vivo biodegradation and bone tissue growth. After the creation of a rodent critical-sized femoral metaphyseal bone defect, PLGA -modified ß-TCP (TP) was prepared by mixing sieved granules of ß-TCP and PLGA (50:50, v/v) for medical use, then TP with dripped 50 µg/0.1 ml and 100 µg/0.1 ml aspirin solution was implanted into the defect of OVX rats until death at 8 weeks. The defected area in distal femurs of rats was harvested for evaluation by histology, micro-CT, biomechanics and real time RT-PCR. The results of our study show that a single-dose local administration of ASP combined with the local usage of TP can increase the healing of defects in OVX rats. Single-dose local administration of aspirin can improve the transcription of genes involved in the regulation of bone formation and vascularization in the defect area, and inhibits osteoclast activity. Furthermore, treatments with a higher single-dose local administration of ASP and TP showed a stronger effect on accelerating the local bone formation than while using a lower dose of ASP. The results from our study demonstrate that the combination of a single-dose local administration of ASP and ß-TCP/PLGA had an additive effect on local bone formation in osteoporosis rats, and bone regeneration by PLGA/ß-TCP/ASP occured in a dose-dependent manner.

Fatigue analysis of computer-aided design/computer-aided manufacturing resin-based composite vs. lithium disilicate glass-ceramic.

Resin-based composite molar crowns made by computer-aided design/computer-aided manufacturing (CAD/CAM) systems have been proposed as an inexpensive alternative to metal-ceramic or all-ceramic crowns. However, there is a lack of scientific information regarding fatigue resistance. This study aimed to analyze the fatigue behavior of CAD/CAM resin-based composite compared with lithium disilicate glass-ceramic. One-hundred and sixty bar-shaped specimens were fabricated using resin-based composite blocks [Lava Ultimate (LU); 3M/ESPE] and lithium disilicate glass-ceramic [IPS e.max press (EMP); Ivoclar/Vivadent]. The specimens were divided into four groups: no treatment (NT); thermal cycling (TC); mechanical cycling (MC); and thermal cycling followed by mechanical cycling (TCMC). Thermal cycling was performed by alternate immersion in water baths of 5°C and 55°C for 5 × 10(4) cycles. Mechanical cycling was performed in a three-point bending test, with a maximum load of 40 N, for 1.2 × 10(6) cycles. In addition, LU and EMP molar crowns were fabricated and subjected to fatigue treatments followed by load-to-failure testing. The flexural strength of LU was not severely reduced by the fatigue treatments. The fatigue treatments did not significantly affect the fracture resistance of LU molar crowns. The results demonstrate the potential of clinical application of CAD/CAM-generated resin-based composite molar crowns in terms of fatigue resistance.

Evaluation of the efficiency of denture cleaners for removing denture adhesives.

OBJECTIVE: We developed a new scoring index for assessing the removability of denture adhesives and evaluated the removal efficiency of denture cleaners. BACKGROUND: Although our understanding of the importance of denture care is increasing, little is known about the effectiveness and efficiency of denture cleaners on denture adhesives. Therefore, guidelines for proper cleaning are necessary. MATERIALS AND METHODS: We used five denture cleaner solutions on two cream adhesives, one powder adhesive and one cushion adhesive. After immersion in the denture cleaners for a designated time, we evaluated the area of the sample plate still covered by denture adhesive. RESULTS: Cream adhesives were removed more completely after immersion in majority of the denture cleaners than in water. Powder adhesive was removed more quickly than cream adhesives. Cushion adhesive was not removed by immersion in either the denture cleaners or water control. CONCLUSION: Some denture cleaners could liquefy cream adhesives more than water, but these differences were not observed in case of powder and cushion adhesives.

Modulation of stromal cell-derived factor 1 alpha (SDF-1α) and its receptor CXCR4 in Porphyromonas gingivalis-induced periodontal inflammation.

BACKGROUND: The production of chemokines by tissue resident cells during inflammation is considered one of the main mechanisms involved in the formation of inflammatory infiltrates. Fibroblasts are the main resident cell type in gingival and periodontal ligament tissues, and their ability to produce chemokine stromal cell-derived factor 1 alpha (SDF-1α) and its receptor CXCR4 under stimulation by gram negative bacteria, Porphyromonas gingivalis, commonly found in periodontal infections was investigated. METHODS: Western blots were used to assess SDF-1α and CXCR4 protein expression levels in human gingival fibroblast cells (HGF-1) induced by Lipopolysaccharide (LPS) from P. gingivalis in the presence or absence of LY294002, a highly selective inhibitor of PI-3K/Akt. RT-PCR and quantitative Real-time PCR was performed using gingival mRNAs from periodontitis patients. Immunohistochemistry was performed to analyze the expression and subcellular localization of SDF-1α and CXCR4, together with NF-kß phosphorylation, in specimens from patients with periodontitis and in an experimental rat periodontitis model. RESULTS: We found that P. gingivalis LPS up-regulated SDF-1α and CXCR4 protein levels and elevated phosphorylation of the SDF-1α-responsive NF-kß and Akt at 24 h in HGF-1 cells. SDF-1α and CXCR4 mRNA and protein expression levels were high in all patients with periodontitis. In the P. gingivalis-induced rat experimental periodontitis model, SDF-1α and CXCR4 immunoreactivity was higher in gingival and periodontal ligament tissues compared to the control. CONCLUSION: Our data showed that PI-3K/Akt is an upstream participant in the P. gingivalis LPS-mediated induction of SDF-1α. Taken together, these results suggest that the chemokine SDF-1α and its receptor CXCR4 contribute to P. gingivalis-induced periodontal inflammation.

The adhesive strength and initial viscosity of denture adhesives.

OBJECTIVE: To examine the initial viscosity and adhesive strength of modern denture adhesives in vitro. MATERIALS AND METHODS: Three cream-type denture adhesives (Poligrip S, Corect Cream, Liodent Cream; PGS, CRC, LDC) and three powder-type denture adhesives (Poligrip Powder, New Faston, Zanfton; PGP, FSN, ZFN) were used in this study. The initial viscosity was measured using a controlled-stress rheometer. The adhesive strength was measured according to ISO-10873 recommended procedures. All data were analyzed independently by one-way analysis of variance combined with a Student-Newman-Keuls multiple comparison test at a 5% level of significance. RESULTS: The initial viscosity of all the cream-type denture adhesives was lower than the powder-type adhesives. Before immersion in water, all the powder-type adhesives exhibited higher adhesive strength than the cream-type adhesives. However, the adhesive strength of cream-type denture adhesives increased significantly and exceeded the powder-type denture adhesives after immersion in water. For powder-type adhesives, the adhesive strength significantly decreased after immersion in water for 60 min, while the adhesive strength of the cream-type adhesives significantly decreased after immersion in water for 180 min. CONCLUSION: Cream-type denture adhesives have lower initial viscosity and higher adhesive strength than powder type adhesives, which may offer better manipulation properties and greater efficacy during application.

GL13K-modified titanium regulates osteogenic differentiation via the NF-κB pathway.

The osteoimmune response plays a crucial regulatory role in the osseointegration of dental implants. Previous studies found the antimicrobial peptide coating (GL13K) could activate the immunomodulatory potential of macrophages (Raw 264.7) and promote osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs). To further investigate the mechanism of interaction between immunomodulation and differentiation, a co-culture model of the representative cells (Raw 264.7 and BMSCs) was constructed to mimic the immune microenvironment. In this system, GL13K coating of titanium implant effectively inhibited the polarization of the inflammatory M1 type and promoted the polarization of the anti-inflammatory M2 type. Furthermore, the inhibited NF-κB signaling pathway and Mip-2 gene expression were found and validated by bioinformatics analysis and virus-induced gene silencing, which significantly affected the tissue repair process. It can be concluded that the GL13K coating had the potential to establish a localized immune microenvironment conducive to osteogenic differentiation through cellular interactions. Subsequent investigations would be dedicated to a thorough examination of the osseointegration effects of GL13K coating.

Current prospect of dental zirconia recycling: A scoping review.

PURPOSE: This scoping review aimed to identify and discuss the recyclability of dental zirconia residuals along with the factors influencing the properties of dental recycled zirconia. STUDY SELECTION: In vitro studies written in both English and Chinese that evaluated the recyclability of dental zirconia residue were selected. A literature search was conducted in Medline, PubMed, Web of Science, and Cochrane Library databases with no restrictions on the publication year. RESULTS: Sixteen studies were included in this review. Residual dental zirconia can be recycled. Cold isostatic pressing improved the density of recycled zirconia compared with uniaxial pressing. Recycled zirconia powder with fine particles enhanced the performance of recycled zirconia compared with coarse particles. A presintering temperature of 950 to 1100°C was suitable for preparing recycled zirconia presintered bodies. Recycled zirconia may require a higher sintering temperature (≥1500°C) compared with commercially available zirconia. Additionally, recycled zirconia powder can enhance the properties of polymethylmethacrylate as a reinforcing filler and can be combined with alumina powder to obtain an alumina/zirconia composite material. CONCLUSIONS: Despite a limited body of literature, the recycling and reutilization of dental zirconia residuals are feasible and reliable, and can reduce economic and environmental losses. Nevertheless, several factors influence the recycling effect, including the particle size, molding techniques, and sintering parameters. In addition, recycled zirconia powder can act as a reinforcing filler, potentially enhancing the mechanical properties of other materials. To realize commercially viable recycled zirconia materials, further studies are essential to comprehensively explore and understand their recycling performance.

Functional and aesthetic results of the Z-shaped and straight lower lip-splitting incision: a randomized clinical trial.

The lip-splitting approach enables excellent access to all areas of the mouth and pharynx to remove tumors; however, traditional lower lip-splitting incisions produce an unsatisfactory scar. To achieve better functional and aesthetic results, we used a Z-shaped incision and compared the functional and aesthetic outcomes of the straight and Z-shaped incisions. Sixty patients who fulfilled the inclusion criteria were randomly divided into two groups and underwent lip-splitting between March 2021 and September 2023. Eventually, 77 patients were reviewed within 6 months and evaluated using the lip function assessment scale, patient and observer scar assessment scale, naïve observer scar assessment scale, and a clinical examination. The Z-shaped incision group performed better in terms of the lip pout movement at 3 months and in the subjective overall opinion, color, irregularity, and pigmentation at 6 months. The Z-shaped incision group had a lower incidence of notched vermilion. In conclusion, Z-shaped lower lip-splitting incisions have better functional and aesthetic outcomes than traditional straight incisions.Trial registration: Public title: Difference between the effect of Z-shaped and vertical incisions of labiobuccal flap on the recovery of lower lip scars. Registration date: 09/03/2021. Registration number: ChiCTR2100044084. Registry URL: http://www.chictr.org.cn .

Effect of denture adhesives on masticatory performance: Multicenter randomized controlled trial.

PURPOSE: The purpose of this study is to investigate the effects of denture adhesives on masticatory performance via a 10-center, parallel, randomized, controlled trial of complete denture wearers in Japan. METHODS: The trial was conducted between September 2013 and October 2016. The inclusion criteria were complete edentulism, willingness to undergo new complete denture treatment, and willingness to return for recall treatment. The exclusion criteria were age 90 years or older, presence of severe systemic illness, inability to understand the questionnaires, wearing metal base complete dentures, denture adhesive user, wearing prosthetics for maxillofacial defects, wearing complete dentures with tissue conditioners, and severe xerostomia. Randomization of the powder-type denture adhesive (powder), cream-type denture adhesive (cream), and control (saline) groups was performed using a sealed envelope system. Masticatory performance was measured using color-changeable chewing gum. Intervention blinding was not feasible. RESULTS: Sixty-seven control, 69 powder, and 64 cream participants are analyzed using the intention-to-treat principle. The participants in all groups show significantly improved masticatory performance at post-intervention (paired t-test with Bonferroni correction P < 0.0001). However, no significant difference in masticatory performance is detected among the three groups (one-way analysis of variance). A significant negative correlation between pre- and post-changes in masticatory performance and intraoral condition scores is observed (Pearson's correlation coefficient, P < 0.0001). CONCLUSIONS: Although denture adhesives improved the masticatory performance of complete denture wearers, their clinical effects are comparable to those of saline solution. The use of denture adhesives is more effective in complete denture wearers with unsatisfactory intraoral conditions.

Effect of Different Retightening Procedures on Screw Stability in External-Hex and Internal Trichannel Connections: An In Vitro Study.

PURPOSE: To evaluate the effect of different abutment screw retightening procedures on the screw stability between the abutment and implant. MATERIALS AND METHODS: External hexagon connection (EHC) and internal trichannel connection (ITC) implants were employed in this study. Each abutment screw was used for the following specific applications (n = 5 for each group): group 0 = abutment was tightened and retightened with a 10-minute interval; group 1 = abutment was tightened and retightened with a 10-minute interval, then loaded for 500,000 cycles; group 2 = abutment was loaded for 83,000 cycles during tightening and retightening, then loaded for 500,000 cycles; group 3 = abutment was loaded for 167,000 cycles during tightening and retightening, then loaded for 500,000 cycles; and group 4 = abutment was loaded for 250,000 cycles during tightening and retightening, then loaded for 500,000 cycles. Both tightening and retightening torques were set at 35 Ncm, and dynamic oblique loading between 0 N and 200 N was applied on the abutment in all groups. The settling values of the abutments after retightening and the abutment removal torque values (RTVs) after testing were measured. RESULTS: No significant differences in settling values were found between EHC and ITC. There were significant differences in the RTVs of EHC implants, but ITC implants showed no difference in RTV with different prosthetic retightening applications. CONCLUSION: The retightening application affected the joint stability of EHC implants but did not affect the settlement and joint stability of ITC implants. Int J Prosthodont 2023;36:181-188. doi: 10.11607/ijp.6863.

Bone Remodeling in Mandible of Wistar Rats with Diabetes Mellitus and Osteoporosis.

OBJECTIVES: This study aimed to determine some of bone molecular expressions and its possible bone remodeling pathway between diabetes mellitus (DM) and osteoporosis model in the mandibular bone of Wistar rats. MATERIALS AND METHODS: Twenty-seven female Wistar rats were divided randomly into control and treatment groups. Treatment groups were injected with streptozotocin intraperitoneally to induce DM (P1) and underwent bilateral ovariectomy to generate osteoporosis (P2). All groups were terminated after 12 weeks. Immunohistochemical and hematoxylin-eosin staining were performed to determine the expression of Runt-related transcription factor 2 (RUNX2), Osterix, vascular endothelial growth factor (VEGF), receptor activator of nuclear factor κB ligand (RANKL), osteoprotegerin (OPG), tartrate-resistant acid phosphatase (TRAP), and observed the osteoblast and osteoclast. Statistical analysis was performed using one-way analysis of variance. RESULTS: The lowest mean of RUNX2 and VEGF expression was found in the P2 group. The lowest mean of Osterix expression was found in the P1 group. Both P1 and P2 groups of osteoblast/osteoclast ratio were decreased. There were no significant differences in the expression of TRAP between all groups; however, increased expression of RANKL/OPG ratio was only found in the P2 group. CONCLUSION: DM and osteoporosis induce changes in the bone remodeling pathway which are represented by a decrease in osteoblast biomarkers and an increase in osteoclast biomarkers.

Human umbilical cord mesenchymal stem cells accelerate and increase implant osseointegration in diabetic rats.

OBJECTIVE: This study was conducted to assess the effect of hUCMSCs injection on the osseointegration of dental implant in diabetic rats via Runt-related Transcription Factor 2 (Runx2), Osterix (Osx), osteoblasts, and Bone Implant Contact (BIC). METHODOLOGY: The research design was a true experimental design using Rattus norvegicus Wistar strain. Rattus norvegicus were injected with streptozotocin to induce experimental diabetes mellitus. The right femur was drilled and loaded with titanium implant. Approximately 1 mm from proximal and distal implant site were injected with hUCMSCs. The control group was given only gelatin solvent injection. After 2 and 4 weeks of observation, the rats were sacrificed for further examination around implant site using immunohistochemistry staining (RUNX2 and Osterix expression), hematoxylin eosin staining, and bone implant contact area. Data analysis was done using ANOVA test. RESULTS: Data indicated a significant difference in Runx2 expression (p<0.001), osteoblasts (p<0.009), BIC value (p<0.000), and Osterix expression (p<0.002). In vivo injection of hUCMSCs successfully increased Runx2, osteoblasts, and BIC value significantly, while decreased Osterix expression, indicating an acceleration of the bone maturation process. CONCLUSION: The results proved hUCMSCs to accelerate and enhance implant osseointegration in diabetic rat models.

Evaluation of the ergonomic sitting position adopted by dental students while using dental simulators.

Background/purpose: Ergonomics in dentistry encourages the work to be in an organized manner, where a dentist achieves highest performance with maximum comfort and minimum physical and psychological effort. The purpose of this study was to evaluate the ergonomic sitting position of dental students from third, fourth and fifth year undergraduate programs while they prepared teeth 46 and 27 as Black Class I preparation for amalgam using dental simulators. Materials and methods: Ten students were randomly selected from each year for this study. Photos and videos were taken from them to record their sitting position as they performed a Black Class I amalgam preparation in Nissin simulators. Results: It was found that more students had a poor ergonomic sitting position while working in mandibular area (60%, torso and neck angle; 53% knee-angle; 50% elbow-angle). When comparing the average score between maxilla and mandible within students of the same year, fourth year students had a significant difference in their average, with a better performance in maxilla (P ≤ 0.01). They also showed better performance in maxillary area compared to fifth-year students (P ≤ 0.008). The main reasons that the students presented as justification for their bad posture were little work time, lack of knowledge, not knowing how to use indirect vision, and poor comfort. Conclusion: Every undergraduate year had a compromised sitting position, with the exception of fourth-year students when working in maxillary area. No correlation between undergraduate year and performance was found.

Questionnaire survey on the satisfaction of SimEx dental education system.

Background/purpose: The SimEx is dental training system that applies new technology in a computerized dental simulator. The purpose of this study was to understand the usability satisfaction of the SimEx dental education and evaluation system by dental students and dentists at Tohoku University. Materials and methods: In this study, the Tohoku University IRB execution number was 2020-3-33. The number of subjects accepted was 59 at Tohoku University and divided into 4 groups based on years of clinical experience (Group A: 0 years; Group B: 1-2 years; Group C: 2-5 years; Group D: at least 5 years), and a total of 58 usability questionnaires were collected. Subjects completed the SimEx Usability Satisfaction Questionnaire after operating the SimEx (EPED Inc., Kaohsiung, Taiwan) course, which contained 16 questions. Results: Among the 58 questionnaires collected by Tohoku University, there were 19 undergraduate students (4th∼6th grade), 12 post-graduate students, 14 residents, and 13 dentists. Significant differences between Group A and Group B, and between Group A and Group D were found (P < 0.05). The same results were obtained for the "experience satisfaction index". In the items where significant differences were found, longer clinical experience tended to result in lower scores. Conclusion: From these results, we can conclude that the SimEx education and evaluation system facilitates students' self-learning, and this system is very useful for continued study and clinical skill training for dentists, especially for students and junior dentists with high usability satisfaction.

ß-Tricalcium Phosphate as Alveolar Bone Grafting in Cleft Lip/Palate: A Systematic Review.

The aim of this systematic review is to describe and identify the prospects of ß-Tricalcium Phosphate (ß-TCP) as an alveolar bone grafting (ABG) material in cleft lip/palate (CL/P) or alveolar bone cleft defects. A systematic review protocol based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2020 (PRISMA 2020) was drafted. The literature search was conducted using MEDLINE/PubMed, Web of Science/ISI Web of Knowledge, Scopus, and the Cochrane Library, with English as the inclusion criterion and no publication year limits. The keywords yielded a total of 5824 publications. After removing duplicates and non-English articles, there were 3196 suitable articles available for evaluation. Subsequently, 1315 studies remained after reviewing titles and abstracts. Furthermore, 85 full articles were assessed for eligibility. After reading the complete texts of those papers, 20 were eventually selected that matched the inclusion requirements. Thirteen out of the twenty studies included in this systematic review were deemed to have a low risk of bias; one had a high risk of bias; and six had a moderate risk of bias due to not reporting randomization. ß-TCP, when used as an ABG material, is biocompatible, visible, practical, offers a less invasive procedure, and does not interfere with orthodontic treatment. Synthetic ß-TCP for ABG can be an alternative to autologous bone grafts under certain terms and conditions. The efficacy of ß-TCP for ABG in CL/P or alveolar bone cleft defects can be enhanced through a tissue engineering approach that combines ß-TCP with growth factors, mesenchymal stem cells, or other graft materials, along with modifications to ß-TCP's physical properties.