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The incidence of invasive fungal infection (IFI) is increasing, especially among patients diagnosed with hematological malignancies due to their immunocompromised nature. Other risk factors include advanced age, exposure to immunosuppressants, neutropenia, and catheter use. Some of the most common IFI organisms reported are Candida and Aspergillus species, and other fungal species, including Scedosporium, Trichosporon, Cryptococcus, and Fusarium have also increasingly been reported in the past years. However, the epidemiologic data on IFI among patients with hematological malignancies in Asian countries are lacking. Therefore, we investigated published epidemiologic data on such cases from the past 10 years (2011-2021) and discuss the challenges faced in the diagnosis and management of IFIs in Asia., (© The Author(s) 2024. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Introduction: Thalassaemia is one of the major health problems in Malaysia. With safe blood transfusion regime, the lifespan of patients with transfusion-dependent thalassaemia (TDT) has improved but at the cost of a higher risk of developing endocrine disorders. It is crucial for us to monitor the iron overload to prevent end organ damage. This study aims to evaluate the iron burden and prevalence of endocrinopathies in patients with TDT in Sarawak., Materials and Methods: This retrospective cohort study was conducted between January 2020 to June 2020 in six government hospitals in Sarawak. A total of 89 patients with TDT, aged 10 years and above, were recruited., Results: Out of the 89 patients, there were 54 males (60.7%) and 35 females (39.3%) with a median age of 21 years (range 10.0-65.0). Sixty-seven (75.3%) patients had betathalassaemia major and 15 (16.9%) patients had haemoglobin E beta-thalassaemia (HbE beta-thalassaemia), remaining seven patients had other genotypes. Thirty-one (34.8%) patients had mean serum ferritin 2500ng/ml and above, and 44 (66.6%) had liver iron concentration (LIC) ≥7mg/g. The prevalence of endocrine disorders in our cohort was 69.7%. The most common endocrinopathies were short stature (n=46, 51.7%), followed by hypogonadism (n=24, 26.9%), delayed puberty (n=23, 25.8%), hypothyroidism (n=10, 11.2%), diabetes mellitus (n=9, 10.1%), impaired glucose tolerance (n=6, 6.7%) and hypoparathyroidism (n=3, 3.3%). Endocrinopathies were significantly associated with age (p=0.01), age at initiating regular blood transfusion (p<0.01) and duration of regular blood transfusion (p<0.01)., Conclusion: Our data shows that the development of endocrinopathies in TDT can be time dependent. Early detection of endocrine-related complications and prompt treatment with iron chelation therapy are important to improve morbidity and mortality. A multidisciplinary approach with good patient-doctor collaboration is the key to improving patient care in our settings.

Ionizing radiation-induced paramagnetic defects in calcified tissues like tooth enamel are indicators of irradiation dose. Hydroxyapatite (HA), the principal constituent in these materials, incorporates a variety of anions (CO 3 2- , F - , Cl - , and SiO 4 4- ) and cations (Mn 2+ , Li + , Cu 2+ , Fe 3+ , Mg 2+ , and Na + ) that directly or indirectly contribute to the formation of stable paramagnetic centers upon irradiation. Here, we used an underexploited synthesis method based on the ambient temperature setting reaction of a self-hardening calcium phosphate cement (CPC) to create carbonate-containing hydroxyapatite (CHA) and investigate its paramagnetic properties following γ-irradiation. Powder X-ray diffraction and IR spectroscopic characterization of the hardened CHA samples indicate the formation of pure B-type CHA cement. CHA samples exposed to γ-radiation doses ranging from 1 Gy to 150 kGy exhibited an electron paramagnetic resonance (EPR) signal from an orthorhombic CO 2 •- free radical. At γ-radiation doses from 30 to 150 kGy, a second signal emerged that is assigned to the CO 3 •- free radical. We observed that the formation of this second species is dose-dependent, which provided a means to extend the useful dynamic range of irradiated CHA to doses >30 kGy. These results indicate that CHA synthesized via a CPC cement is a promising substrate for EPR-based dosimetry. Further studies on the CHA cement are underway to determine the suitability of these materials for a range of biological and industrial dosimetry applications.

Gas-chromatography-mass-spectrometry revealed the presence of various bioactive compounds with anticancer properties in protocorm-like-body (PLB) cultures of a Dendrobium hybrid orchid ( Dendrobium Enopi x Dendrobium Pink Lady). Pre-illumination of red fluorescent light lessened the stimulating effects of light-emitting diodes (LEDs) on secondary metabolites production among in vitro PLB cultures, possibly due to habituation. The highest flavonoid content of 16.79 μmol/ g of fresh weight (FW) was achieved under blue-red (1:1) LED for PLBs pre-treated with white LED for more than 3 subculture cycles. Phenolics content significantly reduced as PLBs pre-cultured under red fluorescent light for 2 subculture cycles were exposed to LED illuminations, where far red LED resulted in the lowest total phenolic content (18.85 μmol/ g FW). High intensity green LED (16.9 μmol/s) enhanced the accumulation of phenolics while amino acids such as L-leucine, glycine and proline exhibited no significant stimulating effect for secondary metabolites production., Competing Interests: The authors declare that there are no conflicts of interest., (© 2020 Published by Elsevier B.V.)

A droplet-vitrification cryopreservation protocol has been successfully developed for Aranda Broga Blue orchid hybrid using protocorm-like bodies (PLBs). However, maximum growth regeneration percentage was recorded at 5% only based on previous report. Thus, to improve growth recovery of cryopreserved PLBs, cryopreservation stages were supplemented with ascorbic acid, tested at 50, 100 and 150 mg/L. However, results demonstrated that exogenous ascorbic acid was not favorable in regeneration of cryopreserved explants (maximum value of 1.67 % with 50 mg/L ascorbic acid supplementation). Total soluble protein and various antioxidant enzyme activities such as catalase (CAT), superoxide dismutase (SOD) and ascorbate peroxidase (APX) were evaluated after each cryopreservation stages in conjunction with the application of exogenous ascorbic acid. Addition of antioxidant must be carefully evaluated and its application may not guarantee successful growth recovery. RAPD and SCoT molecular analysis confirmed the genetic stability of regenerated cryopreserved PLBs as no polymorphism was detected compared to control PLBs culture., Competing Interests: None., (© 2020 Universiti Sains Malaysia.)

Coronavirus disease (COVID-19) has a wide spectrum of clinical manifestations. In this case report, we describe our first case of COVID-19 pneumonia that was complicated by cerebral venous thrombosis and bleeding in a patient with polycythemia vera. Madam A, a 72-year-old lady with polycythemia vera, ischemic stroke, hemorrhoids, diabetes mellitus, hypertension, and dyslipidemia was admitted to the hospital for COVID-19 pneumonia. She was treated with hydroxychloroquine and lopinavir/ritonavir as per hospital protocol. She continued taking hydroxyurea and aspirin for her treatment of polycythemia vera. Subsequently, she developed rectal bleeding when her platelet count was 1247 × 10 3 /μl, even though she was not on an anticoagulant. Her aspirin was withheld. One week later, she was readmitted to the hospital for cerebral venous thrombosis and her D-dimer was 2.02 μg/ml. She was commenced on a therapeutic dose of low molecular weight heparin. Following that, her D-dimer level showed a decreasing trend and normalized upon her discharge. Patients with polycythemia vera are prone to develop thrombotic and bleeding complications. Management of this group of patients has become more complex with COVID-19 infection. It is crucial for us to decide when to start an anticoagulant especially when there is a history of recent bleeding. We need to balance the risks of further bleeding versus potentially fatal thrombotic events. Studies have shown that D-dimer can be used as a clinical marker to predict thrombotic events in COVID-19 infection. Patients with COVID-19 infection and polycythemia vera will benefit from both pharmacological thromboprophylaxis and close monitoring for bleeding., Competing Interests: Conflict of InterestThe authors declare that they have no conflict of interest., (© Springer Nature Switzerland AG 2020, corrected publication 2020.)

Calcium phosphate cement (CPC), functionalized with iron oxide nanoparticles (IONP), is of great promise to promote osteoinduction and new bone formation. In this work, the IONP powder was added into the CPC powder to fabricate CPC + IONP scaffolds and the effects of the novel composite on bone matrix formation and osteogenesis of human dental pulp stem cells (hDPSCs) were explored. A series of CPC + IONP magnetic scaffolds with different IONP contents (1%, 3% and 6%) were fabricated using 5% chitosan solution as the cement liquid. Western blotting and RT-PCR were used to analyze the signaling pathway. The IONP incorporation substantially enhanced the performance of CPC + IONP, with increases in both mechanical strength and cellular activities. The IONP addition greatly promoted the osteogenesis of hDPSCs, elevating the ALP activity, the expression of osteogenic marker genes and bone matrix formation with 1.5-2-fold increases. The 3% IONP incorporation showed the most enhancement among all groups. Activation of the extracellular signal-related kinases WNT/β-catenin in DPSCs was observed, and this activation was attenuated by the WNT inhibitor DKK1. The results indicated that the osteogenic behavior of hDPSCs was likely driven by CPC + IONP via the WNT signaling pathway. In conclusion, incorporate IONP into CPC scaffold remarkably enhanced the spreading, osteogenic differentiation and bone mineral synthesis of stem cell. Therefore, this method had great potential for bone tissue engineering. The novel CPC + IONP composite scaffolds with stem cells are promising to provide an innovative strategy to enhance bone regenerative therapies., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Calcium phosphate cements (CPCs) are frequently used to repair bone defects. Since their discovery in the 1980s, extensive research has been conducted to improve their properties, and emerging evidence supports their increased application in bone tissue engineering. Much effort has been made to enhance the biological performance of CPCs, including their biocompatibility, osteoconductivity, osteoinductivity, biodegradability, bioactivity, and interactions with cells. This review article focuses on the major recent developments in CPCs, including 3D printing, injectability, stem cell delivery, growth factor and drug delivery, and pre-vascularization of CPC scaffolds via co-culture and tri-culture techniques to enhance angiogenesis and osteogenesis., Competing Interests: The authors declare no conflict of interest.

Objective: Secondary caries is a primary reason for dental restoration failures. The objective of this study was to investigate the remineralization of human dentin lesions in vitro via restorations using nanocomposites containing nanoparticles of amorphous calcium phosphate (NACP) or NACP and tetracalcium phosphate (TTCP) for the first time., Methods: NACP was synthesized by a spray-drying technique and incorporated into a resin consisting of ethoxylated bisphenol A dimethacrylate (EBPADMA) and pyromellitic glycerol dimethacrylate (PMGDM). After restoring the dentin lesions with nanocomposites as well as a non-releasing commercial composite control, the specimens were treated with cyclic demineralization (pH 4, 1h per day) and remineralization (pH 7, 23h per day) for 4 or 8 weeks. Calcium (Ca) and phosphate (P) ion releases from composites were measured. Dentin lesion remineralization was measured at 4 and 8 weeks by transverse microradiography (TMR)., Results: Lowering the pH increased ion release of NACP and NACP-TTCP composites. At 56 days, the released Ca concentration in mmol/L (mean±SD; n=3) was (13.39±0.72) at pH 4, much higher than (1.19±0.06) at pH 7 (p<0.05). At 56 days, P ion concentration was (5.59±0.28) at pH 4, much higher than (0.26±0.01) at pH 7 (p<0.05). Quantitative microradiography showed typical subsurface dentin lesions prior to the cyclic demineralization/remineralization treatment, and dentin remineralization via NACP and NACP-TTCP composites after 4 and 8 weeks of treatment. At 8 weeks, NACP nanocomposite achieved dentin lesion remineralization (mean±SD; n=15) of (48.2±11.0)%, much higher than (5.0±7.2)% for dentin in commercial composite group after the same cyclic demineralization/remineralization regimen (p<0.05)., Significance: Novel NACP-based nanocomposites were demonstrated to achieve dentin lesion remineralization for the first time. These results, coupled with acid-neutralization and good mechanical properties shown previously, indicate that the NACP-based nanocomposites are promising for restorations to inhibit caries and protect tooth structures., (Copyright © 2017 The Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.)

Objective: To identify the predictors of time from initial diagnosis of metastatic castration-resistance prostate cancer (mCRPC) to all-cause death within the Shared Equal Access Regional Cancer Hospital cohort., Patients and Methods: We performed a retrospective analysis of 205 mCRPC men. Overall survival was estimated and plotted using the Kaplan-Meier method. The uni- and multivariable overall survival predictors were evaluated with the Cox proportional hazards model. A nomogram was generated to predict overall survival at 1, 2, 3, and 5 years after mCRPC. Concordance index and calibration plot were obtained., Results: A total of 170 men (83%) died over a median follow-up of 41 months. In univariable analysis, older age, more remote year of mCRPC, nonblack race, greater number of bone metastasis, higher prostate-specific antigen (PSA) levels, shorter PSA doubling time, and faster PSA velocity at mCRPC diagnosis were significantly associated with shorter overall survival (all P < .05). In multivariable analysis, older age, more remote year of mCRPC, greater number of bone metastasis, higher PSA levels, and shorter PSA doubling time at mCRPC diagnosis remained significantly associated with shorter overall survival (all P < .05). On the basis of these variables, a nomogram was generated yielding a concordance index of 0.67 and good calibration., Conclusion: The use of clinical parameter such as age, disease burden, and PSA levels and kinetics can be used to estimate overall survival in mCRPC patients., (Copyright © 2016 Elsevier Inc. All rights reserved.)

White spot lesions (WSL) due to enamel demineralization are major complications for orthodontic treatments. Calcium phosphate (CaP) dental resins with Ca and P ion releases are promising for remineralization. However, previous Ca and P releases lasted for only weeks. Experimental orthodontic cements were developed using pyromellitic glycerol dimethacrylate (PMGDM) and ethoxylated bisphenol A dimethacrylate (EBPADMA) at mass ratio of 1:1 (PE); and PE plus 10% of 2-hydroxyethyl methacrylate (HEMA) and 5% of bisphenol A glycidyl dimethacrylate (BisGMA) (PEHB). Particles of amorphous calcium phosphate (ACP) were incorporated into PE and PEHB at 40% filler level. Specimens were tested for bracket-enamel shear bond strength, water sorption, CaP release, and ion recharge and re-release. PEHB+40ACP had higher bracket-enamel bond strength and ion release and rechargeability than PE+40ACP. ACP incorporation into the novel orthodontic cement did not adversely affect the bracket-enamel bond strength. Ion release and re-release from the novel ACP orthodontic cement indicated favorable release and re-release patterns. The recharged orthodontic cement could release CaP ions continuously for four weeks without further recharge. Novel rechargeable orthodontic cement containing ACP was developed with a high bracket-enamel bond strength and the ability to be repeatedly recharged to maintain long-term high levels of CaP ion releases., Competing Interests: The authors Xu H, Zhang L, Weir MD. declares the U.S. Provisional Patent Application. Number: 62/1121,438 (2015).

Objective: To investigate predictors of time to metastasis among men treated with androgen deprivation therapy for nonmetastatic prostate cancer who developed castration-resistant prostate cancer (CRPC) within the Shared Equal Access Regional Cancer Hospital cohort., Methods: This is a retrospective analysis of 458 nonmetastatic CRPC men. Metastases were detected in routine bone scans or other imaging tests. Predictors of time to metastasis were analyzed using proportional hazards model with CRPC as time zero., Results: A total of 256 (56%) men were diagnosed with metastatic disease over a median follow-up of 36 months. Metastasis-free survival was 79%, 65%, 52%, 47%, and 41% at 1, 2, 3, 4, and 5 years after CRPC, respectively. In multivariable analysis, Gleason score 8-10 (hazard ratio [HR] = 1.61; P = .026), receiving primary localized treatment (HR = 1.38; P = .028), higher prostate-specific antigen (PSA) levels at CRPC diagnosis (logPSA HR = 1.64; P < .001), and PSA doubling time ≤6 months (HR = 1.42; P = .040) were independently associated with shorter time to metastasis. Race, year of CRPC, age, and time from androgen deprivation therapy to CRPC were not associated with metastasis., Conclusion: Among nonmetastatic CRPC men, nearly 60% developed metastatic disease during the first 5 years, with most of the metastasis occurring within the first 3 years. Higher Gleason score, receiving primary treatment, higher PSA, and shorter PSA doubling time were independently associated with shorter time to metastasis. Therefore, these variables can be used to stratify patients according to metastasis risk., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Objectives: Calcium phosphate (CaP) composites with Ca and P ion release can remineralize tooth lesions and inhibit caries. But the ion release lasts only a few months. The objectives of this study were to develop rechargeable CaP dental composite for the first time, and investigate the Ca and P recharge and re-release of composites with nanoparticles of amorphous calcium phosphate (NACP) to achieve long-term inhibition of caries., Methods: Three NACP nanocomposites were fabricated with resin matrix of: (1) bisphenol A glycidyl dimethacrylate (BisGMA) and triethylene glycol dimethacrylate (TEGDMA) at 1:1 mass ratio (referred to as BT group); (2) pyromellitic glycerol dimethacrylate (PMGDM) and ethoxylated bisphenol A dimethacrylate (EBPADMA) at 1:1 ratio (PE group); (3) BisGMA, TEGDMA, and Bis[2-(methacryloyloxy)ethyl] phosphate (BisMEP) at 2:1:1 ratio (BTM group). Each resin was filled with 20% NACP and 50% glass particles, and the composite was photo-cured. Specimens were tested for flexural strength and elastic modulus, Ca and P ion release, and Ca and P ion recharge and re-release., Results: NACP nanocomposites had strengths 3-fold of, and elastic moduli similar to, commercial resin-modified glass ionomer controls. CaP ion recharge capability was the greatest for PE group, followed by BTM group, with BT group being the lowest (p<0.05). For each recharge cycle, CaP re-release reached similarly high levels, showing that CaP re-release did not decrease with more recharge cycles. After six recharge/re-release cycles, NACP nanocomposites without further recharge had continuous CaP ion release for 42 d., Significance: Novel rechargeable CaP composites achieved long-term and sustained Ca and P ion release. Rechargeable NACP nanocomposite is promising for caries-inhibiting restorations, and the Ca and P ion recharge and re-release method has wide applicability to dental composites, adhesives, cements and sealants to achieve long-term caries-inhibition., (Copyright © 2015 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.)

Background: To evaluate PSA levels and kinetic cutoffs to predict positive bone scans for men with non-metastatic castration-resistant prostate cancer (CRPC) from the Shared Equal Access Regional Cancer Hospital (SEARCH) cohort., Methods: Retrospective analysis of 531 bone scans of 312 clinically CRPC patients with no known metastases at baseline treated with a variety of primary treatment types in the SEARCH database. The association of patients' demographics, pathological features, PSA levels and kinetics with risk of a positive scan was tested using generalized estimating equations., Results: A total of 149 (28%) scans were positive. Positive scans were associated with younger age (odds ratio (OR)=0.98; P=0.014), higher Gleason scores (relative to Gleason 2-6, Gleason 3+4: OR=2.03, P=0.035; Gleason 4+3 and 8-10: OR=1.76, P=0.059), higher prescan PSA (OR=2.11; P<0.001), shorter prescan PSA doubling time (PSADT; OR=0.53; P<0.001), higher PSA velocity (OR=1.74; P<0.001) and more remote scan year (OR=0.92; P=0.004). Scan positivity was 6, 14, 29 and 57% for men with PSA<5, 5-14.9, 15-49.9 and ⩾ 50 ng ml(-1), respectively (P-trend <0.001). Men with PSADT ⩾ 15, 9-14.9, 3-8.9 and <3 months had a scan positivity of 11, 22, 34 and 47%, correspondingly (P-trend <0.001). Tables were constructed using PSA and PSADT to predict the likelihood of a positive bone scan., Conclusions: PSA levels and kinetics were associated with positive bone scans. We developed tables to predict the risk of positive bone scans by PSA and PSADT. Combining PSA levels and kinetics may help select patients with CRPC for bone scans.

Nonsurgical local treatment of a periapical lesion arising from trauma or bacterial infection is a promising innovative approach. The present study investigated the feasibility of developing injectable amorphous calcium phosphate nanoparticles (ACP NPs) and ACP NPs loaded with an anti-inflammatory drug; ibuprofen (IBU-ACP NPs) in the form of thermoreversible in situ gels to treat periapical lesions with the stimulation of bone formation. NPs were produced by a spray-drying technique. Different formulations of Poloxamer 407 were incorporated with/without the produced NPs to form injectable gels. A drug release study was carried out. A 3 month in vivo test on a dog model also was assessed. Results showed successful incorporation of the drug into the NPs of CP during spray drying. The particles had mean diameters varying from 100 to 200 nm with a narrow distribution. A drug release study demonstrated controlled IBU release from IBU-ACP NPs at a pH of 7.4 over 24 h. The gelation temperature of the injectable in situ gels based on Poloxamer 407 was measured to be 30 °C. After 3 months of implantation in dogs, the results clearly demonstrated that the inclusion of ACP NPs loaded with IBU showed high degrees of periapical bone healing and cementum layer deposition around the apical root tip.

Low mechanical strengths and inadequate bioactive material-tissue interactions of current synthetic materials limit their clinical applications in bone regeneration. Here, we demonstrate gelatin modified siloxane-calcium silicate (GEMOSIL-CS), a nanocomposite made of gelatinous hydroxyapatite with in situ pozzolanic formation of calcium silicate (CS) interacting among gelatin, silica and Calcium Hydroxide (Ca(OH)2). It is shown the formation of CS matrices, which chemically bonds to the gelatinous hydroxyapatite, provided hygroscopic reinforcement mechanism and promoted both in vitro and in vivo osteogenic properties of GEMOSIL-CS. The formation of CS was identified by Fourier transform infrared spectroscopy (FTIR) and powder X-ray diffraction. The interfacial bindings within nanocomposites were studied by FTIR and thermogravimetric analysis. Both gelatin and CS have been found critical to the structure integrity and mechanical strengths (93 MPa in compressive strength and 58.9 MPa in biaxial strength). The GEMOSIL-CS was biocompatible and osteoconductive as result of type I collagen secretion and mineralized nodule formation from MC3T3 osteoblasts. SEM and TEM indicated the secretion of collagen fibers and mineral particles as the evidence of mineralization in the early stage of osteogenic differentiation. In vivo bone formation capability was performed by implanting GEMOSIL-CS into rat calvarial defects for 12 weeks and the result showed comparable new bone formation between GEMOSIL-CS group (20%) and the control (20.19%). The major advantage of GEMOSIL-CS composites is in situ self-hardening in ambient or aqueous environment at room temperature providing a simple, fast and cheap method to produce porous scaffolds.

Aim of this study was to develop a novel fluorapatite-forming calcium phosphate cement (FA-CPC) with tricalcium silicate (TCS) for endodontic applications and to examine its in vitro and in vivo characteristics. The FA-CPC powder consisted of 62.8% CaHPO4, 30.8% CaCO3, and 6.4% NaF. One part of TCS was combined with 9 parts of FA-CPC powder (FA-CPC with TCS). A 1.5 M phosphate solution was used as cement liquid. Setting time (ST), diametral tensile strength (DTS), phase composition by X-ray diffraction (XRD), and cement alkalinity were analyzed. Cement biocompatibility was assessed using rat subcutaneous model. Cement ST was 10.3±0.6 min and DTS was 3.89±0.76 MPa. XRD patterns showed that highly crystalline apatitic material was the only significant phase present and pH value was approximate 11.0. FA-CPC with TCS demonstrated similar biocompatibility as that of mineral trioxide aggregate control. These results suggest that FA-CPC with TCS may be useful for endodontic applications.

Increasing the concentration of free fluoride in oral fluids is an important goal in the use of topical fluoride agents. Although sodium lauryl sulfate (SLS) is a common dentifrice ingredient, the influence of this ion on plaque fluid and salivary fluid fluoride has not been examined. The purpose of this study was to investigate the effect of SLS on these parameters and to examine the effect of this ion on total (or whole) plaque fluoride, an important source of plaque fluid fluoride after a sufficient interval following fluoride administration, and on total salivary fluoride, a parameter often used as a surrogate measure of salivary fluid fluoride. Ten subjects accumulated plaque for 48 h before rinsing with a 12 mmol/l NaF (228 µg/g F) rinse containing or not containing 0.5% (w/w) SLS. SLS had no statistically significant effect on total plaque and total saliva fluoride but significantly increased salivary fluid and plaque fluid fluoride (by 147 and 205%, respectively). These results suggest that the nonfluoride components of topical agents can be manipulated to improve the fluoride release characteristics from oral fluoride reservoirs and that statistically significant change may be observed in plaque fluid and salivary fluid fluoride concentrations that may not be observed in total plaque and total saliva fluoride concentrations.

Müllerian duct anomalies (MDA) occur due to abnormal development of the uterus, cervix, and vagina, many times affecting a woman's ability to conceive and carry a pregnancy to term. The spectrum of possible abnormalities are related to the development of two separate Müllerian systems, which then fuse and subsequently undergo degeneration of the fused segments. This multiphasic development explains the multiple variations within the scheme of MDA classification. The purpose of this article is to review the embryologic development of the Müllerian ducts, relate the development to the most commonly used classification system, and review the magnetic resonance imaging (MRI) assessment of Müllerian duct anomalies. A brief review of the treatment options, as they relate to the imaging diagnosis, will be provided as well., (© 2014 Wiley Periodicals, Inc.)

A new bioresorbable polylactide/calcium phosphate composite with improved mechanical strengths and a more basic filler, tetracalcium phosphate (TTCP), was prepared by melt compounding. N-(2-aminoethyl)-3-aminoproplytrimethoxysilane (AEAPS) and pyromellitic dianhydride (PMDA) were used to improve the interfacial adhesion between TTCP and polylactide (PLA). While AEAPS improved the dispersion of TTCP in the matrix, PMDA might react with the terminal hydroxyl group of PLA and the amino group on the surface of AEAPS modified TTCP, which could further enhance the interfacial strength. The tensile strength was improved to 68.4 MPa for the PLA/TTCP-AEAPS composite from 51.5 MPa for the PLA/TTCP composite (20 wt% of TTCP). Dynamic mechanical analysis suggested that there was a 51 % improvement in storage modulus compared to that of PLA alone, when PMDA (0.2 wt% of PMDA) was incorporated into the PLA/TTCP-AEAPS composite (5 wt% of TTCP). Using this new bioresorbable PLA composite incorporated with a more basic filler for biomedical application, the inflammation and allergic effect resulted from the degraded acidic product are expected to be reduced.

Objective: Recurrent caries at the margins is a primary reason for restoration failure. The objectives of this study were to develop bonding agent with the double benefits of antibacterial and remineralizing capabilities, to investigate the effects of NACP filler level and solution pH on Ca and P ion release from adhesive, and to examine the antibacterial and dentin bond properties., Methods: Nanoparticles of amorphous calcium phosphate (NACP) and a quaternary ammonium monomer (dimethylaminododecyl methacrylate, DMADDM) were synthesized. Scotchbond Multi-Purpose (SBMP) primer and adhesive served as control. DMADDM was incorporated into primer and adhesive at 5% by mass. NACP was incorporated into adhesive at filler mass fractions of 10%, 20%, 30% and 40%. A dental plaque microcosm biofilm model was used to test the antibacterial bonding agents. Calcium (Ca) and phosphate (P) ion releases from the cured adhesive samples were measured vs. filler level and solution pH of 7, 5.5 and 4., Results: Adding 5% DMADDM and 10-40% NACP into bonding agent, and water-aging for 28 days, did not affect dentin bond strength, compared to SBMP control at 1 day (p>0.1). Adding DMADDM into bonding agent substantially decreased the biofilm metabolic activity and lactic acid production. Total microorganisms, total streptococci, and mutans streptococci were greatly reduced for bonding agents containing DMADDM. Increasing NACP filler level from 10% to 40% in adhesive increased the Ca and P ion release by an order of magnitude. Decreasing solution pH from 7 to 4 increased the ion release from adhesive by 6-10 folds., Significance: Bonding agents containing antibacterial DMADDM and remineralizer NACP were formulated to have Ca and P ion release, which increased with NACP filler level from 10% to 40% in adhesive. NACP adhesive was "smart" and dramatically increased the ion release at cariogenic pH 4, when these ions would be most-needed to inhibit caries. Therefore, bonding agent containing DMADDM and NACP may be promising to inhibit biofilms and remineralize tooth lesions thereby increasing the restoration longevity., (Copyright © 2014 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.)

The purpose of this study is to determine whether a calcium (Ca) prerinse used before a 228 µg/g (ppm) fluoride (F) rinse would induce the formation of 'calcium fluoride-like' (CaF2-like) deposits in human dental plaque. Sixty minutes after the use of the Ca prerinse/F rinse, plaque samples were collected from 10 volunteers, homogenized, and split into 2 aliquots. The plaque mass from one aliquot was then extracted with a 'plaque-like' solution that extracted all the CaF2-like deposits. The total F in both aliquots was then determined and compared. The results demonstrated that, as in previous studies, the Ca prerinse induced large increases in plaque fluid and total plaque F. However, unlike previous results without the Ca prerinse, 30% of the plaque F deposits were CaF2 or CaF2-like. Given that maintaining an elevated F concentration in the vicinity of a developing lesion may play an important role in the cariostatic effect of this ion, and the potential advantages of CaF2-like deposits as an F source, these results suggest that a Ca prerinse may increase the cariostatic effect of topical agents.

Surface modification of titanium dioxide (TiO 2 ) nanoparticle is essential to control its surface properties, thereby to enhance its cell penetration capability, reduce its cytotoxicity, or improve its biocompatibility. In order to graft polyvinyl acetate onto TiO 2 nanoparticles, xanthate was chemically immobilized on the surface of TiO 2 by acylation followed by nucleophilic substitution with a carbodithioate salt. Reversible addition fragmentation chain transfer polymerization was conducted to graft vinyl acetate onto the surface of TiO 2 . Both the TiO 2 -xanthate and TiO 2 -polyvinyl acetate hybrids were characterized by UV-Vis spectroscopy, Fourier transform infrared spectroscopy, and thermogravimetric analysis. The chemical immobilization of xanthate on the surface of TiO 2 and the subsequent controlled polymerization provide useful insight for decoration and modification of TiO 2 and other nanoparticles.

Addition of filler to polylactic acid (PLA) may affect its crystallization behavior and mechanical properties. The effects of talc and hydroxyapatite (HA) on the thermal and mechanical properties of two types of PLA (one amorphous and one semicrystalline) have been investigated. The composites were prepared by melt blending followed by injection molding. The molecular weight, morphology, mechanical properties, and thermal properties have been characterized by gel permeation chromatography (GPC), scanning electron microscope (SEM), instron tensile tester, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and dynamic mechanical analysis (DMA). It was found that the melting blending led to homogeneous distribution of the inorganic filler within the PLA matrix but decreased the molecular weight of PLA. Regarding the filler, addition of talc increased the crystallinity of PLA, but HA decreased the crystallinity of PLA. The tensile strength of the composites depended on the crystallinity of PLA and the interfacial properties between PLA and the filler, but both talc and HA filler increased the toughness of PLA.

In this experimental study, two surface modification techniques were investigated for their effect on heat transfer enhancement. One of the methods employed the particle (grit) blasting to create microscale indentations, while the other used plasma spray coating to create microscale protrusions on Al 6061 (aluminum alloy 6061) samples. The test surfaces were characterized using scanning electron microscopy (SEM) and confocal scanning laser microscopy. Because of the surface modifications, the actual surface area was increased up to 2.8× compared to the projected base area, and the arithmetic mean roughness value (Ra) was determined to vary from 0.3 μm for the reference smooth surface to 19.5 μm for the modified surfaces. Selected samples with modified surfaces along with the reference smooth surface were then evaluated for their heat transfer performance in spray cooling tests. The cooling system had vapor-atomizing nozzles and used anhydrous ammonia as the coolant in order to achieve heat fluxes up to 500 W/cm(2) representing a thermal management setting for high power systems. Experimental results showed that the microscale surface modifications enhanced heat transfer coefficients up to 76% at 500 W/cm(2) compared to the smooth surface and demonstrated the benefits of these practical surface modification techniques to enhance two-phase heat transfer process.

We have designed a 2-spinnerette device that can directly electrospin nanofiber scaffolds containing a gradient in composition that can be used to engineer interfacial tissues such as ligament and tendon. Two types of nanofibers are simultaneously electrospun in an overlapping pattern to create a nonwoven mat of nanofibers containing a composition gradient. The approach is an advance over previous methods due to its versatility - gradients can be formed from any materials that can be electrospun. A dye was used to characterize the 2-spinnerette approach and applicability to tissue engineering was demonstrated by fabricating nanofibers with gradients in amorphous calcium phosphate nanoparticles (nACP). Adhesion and proliferation of osteogenic cells (MC3T3-E1 murine pre-osteoblasts) on gradients was enhanced on the regions of the gradients that contained higher nACP content yielding a graded osteoblast response. Since increases in soluble calcium and phosphate ions stimulate osteoblast function, we measured their release and observed significant release from nanofibers containing nACP. The nanofiber-nACP gradients fabricated herein can be applied to generate tissues with osteoblast gradients such as ligaments or tendons. In conclusion, these results introduce a versatile approach for fabricating nanofiber gradients that can have application for engineering graded tissues.

Secondary caries remains the main problem limiting the longevity of composite restorations. The objective of this study was to investigate the remineralization of demineralized human enamel in vitro via a nanocomposite containing nanoparticles of amorphous calcium phosphate (NACP). NACP were synthesized by a spray-drying technique and incorporated into a dental resin. First, caries-like subsurface enamel lesions were created via an acidic solution. Then, NACP nanocomposite or a commercial fluoride-releasing control composite was placed on the demineralized enamel, along with control enamel without a composite. These specimens were then treated with a cyclic demineralization/remineralization regimen for 30 days. Quantitative microradiography showed typical enamel subsurface demineralization before cyclic demineralization/remineralization treatment, and significant remineralization in enamel under the NACP nanocomposite after the demineralization/remineralization treatment. The NACP nanocomposite had the highest enamel remineralization (mean ± SD; n = 6) of 21.8 ± 3.7%, significantly higher than the 5.7 ± 6.9% for fluoride-releasing composite (p < 0.05). The enamel group without composite had further demineralization of -26.1 ± 16.2%. In conclusion, a novel NACP nanocomposite was effective in remineralizing enamel lesions in vitro. Its enamel remineralization was 4-fold that of a fluoride-releasing composite control. Combined with the good mechanical and acid-neutralization properties reported earlier, the new NACP nanocomposite is promising for remineralization of demineralized tooth structures.

Half of all dental restorations fail within 10 years, with secondary caries and restoration fracture being the main reasons. Calcium phosphate (CaP) composites can release Ca and PO(4) ions and remineralize tooth lesions. However, there has been no report on their long-term mechanical durability. The objective of this study was to investigate the wear, thermal-cycling, and water-aging of composites containing amorphous calcium phosphate nanoparticles (NACP). NACP of 112-nm and glass particles were used to fabricate four composites: (1) 0% NACP+75% glass; (2) 10% NACP+65% glass; (3) 15% NACP+60% glass; and (4) 20% NACP+50% glass. Flexural strength and elastic modulus of NACP nanocomposites were not degraded by thermal-cycling. Wear depth increased with increasing NACP filler level. Wear depths of NACP nanocomposites after 4 × 10(5) cycles were within the range for commercial controls. Mechanical properties of all the tested materials decreased with water-aging time. After 2 years, the strengths of NACP nanocomposites were moderately higher than the control composite, and much higher than the resin-modified glass ionomers. The mechanism of strength loss for resin-modified glass ionomer was identified as microcracking and air-bubbles. NACP nanocomposites and control composite were generally free of microcracks and air-bubbles. In conclusion, combining NACP nanoparticles with reinforcement glass particles resulted in novel nanocomposites with long-term mechanical properties higher than those of commercial controls, and wear within the range of commercial controls. These strong long-term properties, plus the Ca-PO(4) ion release and acid-neutralization capability reported earlier, suggest that the new NACP nanocomposites may be promising for stress-bearing and caries-inhibiting restorations., (Copyright © 2012 Wiley Periodicals, Inc.)

Objectives: Fluoride (F) releasing dental restoratives are promising to promote remineralization and combat caries. The objectives of this study were to develop nanocomposite containing calcium fluoride nanoparticles (nCaF(2)), and to investigate the long-term mechanical durability including wear, thermal-cycling and long-term water-aging behavior., Methods: Two types of fillers were used: nCaF(2) with a diameter of 53 nm, and glass particles of 1.4 μm. Four composites were fabricated with fillers of: (1) 0% nCaF(2)+65% glass; (2) 10% nCaF(2)+55% glass; (3) 20% nCaF(2)+45% glass; (4) 30% nCaF(2)+35% glass. Three commercial materials were also tested. Specimens were subjected to thermal-cycling between 5°C and 60°C for 10(5) cycles, three-body wear for 4×10(5) cycles, and water-aging for 2 years., Results: After thermal-cycling, the nCaF(2) nanocomposites had flexural strengths in the range of 100-150 MPa, five times higher than the 20-30 MPa for resin-modified glass ionomer (RMGI). The wear scar depth showed an increasing trend with increasing nCaF(2) filler level. Wear of nCaF(2) nanocomposites was within the range of wear for commercial controls. Water-aging decreased the strength of all materials. At 2 years, flexural strength was 94 MPa for nanocomposite with 10% nCaF(2), 60 MPa with 20% nCaF(2), and 48 MPa with 30% nCaF(2). They are 3-6 fold higher than the 15 MPa for RMGI (p<0.05). SEM revealed air bubbles and cracks in a RMGI, while composite control and nCaF(2) nanocomposites appeared dense and solid., Significance: Combining nCaF(2) with glass particles yielded nanocomposites with long-term mechanical properties that were comparable to those of a commercial composite with little F release, and much better than those of RMGI controls. These strong long-term properties, together with their F release being comparable to RMGI as previously reported, indicate that the nCaF(2) nanocomposites are promising for load-bearing and caries-inhibiting restorations., (Copyright © 2012 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.)

Objective: Müllerian duct anomalies can adversely affect pregnancy outcomes and can result in clinical symptoms. This article will review the appropriate management of patients with müllerian duct abnormalities., Conclusion: Whereas uterine and vaginal septa, vaginal agenesis, and unicornuate uterus can be managed surgically, other uterine anomalies tend to be managed clinically. Hence, appropriate management depends on a reliable assessment of pelvic anatomy. MRI can accurately display female pelvic anatomy and is, therefore, useful in guiding therapy.

Bioresorbable composite made from degradable polymers, e.g., polylactide (PLA), and bioactive calcium phosphates, e.g., hydroxyapatite (HA), are clinically desirable for bone fixation, repair and tissue engineering because they do not need to be removed by surgery after the bone heals. However, preparation of PLA/HA composite from non-modified HA usually results in mechanical strength reductions due to a weak interface between PLA and HA. In this study, a calcium-phosphate/phosphonate hybrid shell was developed to introduce a greater amount of reactive hydroxyl groups onto the HA particles. Then, PLA was successfully grafted on HA by surface-initiated polymerization through the non-ionic surface hydroxyl groups. Thermogravimetric analysis indiated that the amount of grafted PLA on HA can be up to 7 %, which is about 50 % greater than that from the literature. PLA grafted HA shows significantly different pH dependent ζ-potential and particle size profiles from those of uncoated HA. By combining the phosphonic acid coupling agent and surface initiated polymerization, PLA could directly link to HA through covalent bond so that the interfacial interaction in the PLA/HA composite can be significantly improved. The diametral tensile strength of PLA/HA composite prepared from PLA-grafted HA was found to be over twice that of the composite prepared from the non-modified HA. Moreover, the tensile strength of the improved composite was 23 % higher than that of PLA alone. By varying additional variables, this approach has the potential to produce bioresorbable composites with improved mechanical properties that are in the range of natural bones, and can have wide applications for bone fixation and repair in load-bearing areas.

Objectives: The main challenges facing composite restorations are secondary caries and bulk fracture. The objectives of this study were to synthesize novel nanoparticles of amorphous calcium phosphate (NACP), develop NACP nanocomposite with calcium (Ca) and phosphate (PO(4)) ion release to combat caries, and investigate the effects of NACP filler level and glass co-filler reinforcement on composite properties., Methods: NACP (diameter=116 nm) were synthesized via a spray-drying technique for the first time. Since the local plaque pH in the oral cavity can decrease to 5 or 4, photo-activated composites were tested with immersion in solutions of pH 7, 5.5, and 4. Composite mechanical properties as well as Ca and PO(4) ion release were measured vs. pH and filler level., Results: Increasing the NACP filler level increased the ion release. At 28 d and pH 4, the Ca release was (4.66±0.05)mmol/L at 20% NACP, much higher than (0.33±0.08) at 10% NACP (p<0.05). Decreasing the pH increased the ion release. At 20% NACP, the PO(4) release at 28 d was (1.84±0.12)mmol/L at pH 4, higher than (0.59±0.08) at pH 5.5, and (0.12±0.01) at pH 7 (p<0.05). However, pH had little effect on composite mechanical properties. Flexural strength at 15% NACP was (96±13)MPa at pH 4, similar to (89±13)MPa at pH 5.5, and (89±19)MPa at pH 7 (p>0.1). The new NACP nanocomposites had strengths that were 2-fold those of previous calcium phosphate composites and resin-modified glass ionomer control., Significance: NACP composites were developed for the first time. Their strengths matched or exceeded a commercial composite with little ion release, and were 2-fold those of previous Ca-PO(4) composites. The nanocomposite was "smart" as it greatly increased the ion release at a cariogenic pH 4, when these ions would be most needed to inhibit caries. Hence, the new NACP composite may be promising for stress-bearing and caries-inhibiting restorations., (Copyright © 2011 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.)

Segmentation of the left ventricle is important in the assessment of cardiac functional parameters. Manual segmentation of cardiac cine MR images for acquiring these parameters is time-consuming. Accuracy and automation are the two important criteria in improving cardiac image segmentation methods. In this paper, we present a comprehensive approach to segment the left ventricle from short axis cine cardiac MR images automatically. Our method incorporates a number of image processing and analysis techniques including thresholding, edge detection, mathematical morphology, and image filtering to build an efficient process flow. This process flow makes use of various features in cardiac MR images to achieve high accurate segmentation results. Our method was tested on 45 clinical short axis cine cardiac images and the results are compared with manual delineated ground truth (average perpendicular distance of contours near 2 mm and mean myocardium mass overlapping over 90%). This approach provides cardiac radiologists a practical method for an accurate segmentation of the left ventricle.

Previously, nano-sized calcium fluoride (CaF₂) particles were prepared using a spray drying method by simultaneously feeding Ca(OH)₂ and NH₄F solutions to a two-liquid nozzle. The aim of the present study was to prepare better-dispersed nano-CaF₂ particles by co-forming a soluble salt, sodium chloride (NaCl). NaCl of various concentrations were added to the NH(4) F solution, leading to formation of (CaF₂ +NaCl) composites with CaF₂ /NaCl molar ratios of 4/1, 4/4, and 4/16. Pure nano-CaF₂ was also prepared as the control. Powder X-ray diffraction analysis showed that the products contained crystalline CaF₂ and NaCl. Scanning electron microscopy examinations showed that both the CaF₂ /NaCl composite and pure CaF₂ particles were about (50-800) nm in size and consisted of primary CaF₂ particles of < 50 nm in size. BET surface area measurements showed similar primary particle sizes for all samples. Dynamic light scattering measurements showed that the washed (CaF₂+NaCl) particles were much smaller than the pure CaF₂ as the dissolution of NaCl "freed" most of the primary CaF₂ particles, leading to a greater degree of particle dispersion. The well-dispersed nano-CaF₂ may be expected to be a more effective anticaries agent than NaF by providing longer lasting elevations of fluoride concentrations in oral fluids., (Copyright © 2011 Wiley Periodicals, Inc.)

Dental composites do not hinder bacteria colonization and plaque formation. Caries at the restoration margins is a frequent reason for replacement of existing restorations, which accounts for 50 to 70% of all restorations. The objectives of this study were to examine the filler level effect on nanocomposite containing nanoparticles of amorphous calcium phosphate (NACP) and investigate the load-bearing and acid-neutralizing properties and bacteria inhibition. NACP with 116-nm particle size were synthesized via a spray-drying technique and incorporated into a resin. Flexural strength of nanocomposite with 10 to 30% NACP fillers matched the strength of a commercial hybrid composite (p > 0.1). Nanocomposite with 40% NACP matched the strength of a microfill composite, which was 2-fold that of a resin-modified glass ionomer. Nanocomposite with 40% NACP neutralized a lactic acid solution of pH 4 by rapidly increasing the pH to 5.69 in 10 min. In contrast, the commercial controls had pH staying at near 4. Using Streptoccocus mutans, an agar disk-diffusion test showed no inhibition zone for commercial controls. In contrast, the inhibition zone was (2.5 ± 0.7) mm for nanocomposite with 40% NACP. Crystal violet staining showed that S. mutans coverage on nanocomposite was 1/4 that on commercial composite. In conclusion, novel calcium-phosphate nanocomposite matched the mechanical properties of commercial composite and rapidly neutralized lactic acid of pH 4. The nanocomposite appeared to moderately reduce the S. mutans growth, and further study is needed to obtain strong antimicrobial properties. The new nanocomposite may have potential to reduce secondary caries and restoration fracture, two main challenges facing tooth cavity restorations., (Copyright © 2011 Wiley Periodicals, Inc.)

Background: There is general concern that high-risk patients are more susceptible to the adverse effect of pneumoperitoneum and they are often denied laparoscopic surgery. This study investigated the impact of laparoscopic colorectal cancer resection for patients with high operative risk, which was defined as American Society of Anesthesiologist classes 3 and 4., Methods: Three hundred thirty-five consecutive high-risk patients who had colorectal cancer resection by open or laparoscopic surgery were included. The patient and tumor characteristics and operative outcomes were recorded prospectively, and comparison was made between the two groups., Results: Compared to open surgery, patients with laparoscopic resection had a shorter hospital stay (8 [6-12] vs. 6 [4-9] days; P < 0.001), less blood loss (200 [100-400] vs. 140 [80-250] mL; P = 0.006), reduced cardiac complication rate (13.2% vs. 3.7%; P = 0.006), overall operative complication rate (36.6% vs. 21.3%; P = 0.006), and a trend toward a lower mortality rate (4.4% vs. 0.9%; P = 0.083). There was no difference in 3-year overall and disease-free survival between two groups. Operative blood loss (P = 0.035; odds ratio = 2.69; 95% confidence interval, 1.00-6.78) and open surgery (P = 0.007; odds ratio = 2.31; 95% confidence interval, 1.26-4.23) were independent factors for occurrence of complication., Conclusions: Laparoscopic colorectal cancer resection is associated with more favorable short-term results and should be recommended as the preferred treatment option for high-risk patients.

There is a need for combinatorial and high-throughput methods for screening cell-biomaterial interactions to maximize tissue generation in scaffolds. Current methods employ a flat two-dimensional (2D) format even though three-dimensional (3D) scaffolds are more representative of the tissue environment in vivo and cells are responsive to topographical differences of 2D substrates and 3D scaffolds. Thus, combinatorial libraries of 3D porous scaffolds were developed and used to screen the effect of nano-amorphous calcium phosphate (nACP) particles on osteoblast response. Increasing nACP content in poly(ε-caprolactone) (PCL) scaffolds promoted osteoblast adhesion and proliferation. The nACP-containing scaffolds released calcium and phosphate ions which are known to activate osteoblast function. Scaffold libraries were fabricated in two formats, gradients and arrays, and the magnitude of the effect of nACP on osteoblast proliferation was greater for arrays than gradients. The enhanced response in arrays can be explained by differences in cell culture designs, diffusional effects and differences in the ratio of "scaffold mass to culture medium". These results introduce a gradient library approach for screening large pore 3D scaffolds and demonstrate that inclusion of the nACP particles enhances osteoblast proliferation in 3D scaffolds. Further, comparison of gradients and arrays suggests that gradients were more sensitive for detecting effects of scaffold composition on cell adhesion (short time points, 1 day) whereas arrays were more sensitive at detecting effects on cell proliferation (longer time points, 14 day)., (Published by Elsevier Ltd.)

A calcium phosphate cement (CPC) was shown to have the necessary attributes for endodontic materials except adequate basicity needed for antimicrobial properties. To enhance its basicity, tricalcium silicate (Ca3SiO5), a highly alkaline compound, was added to CPC at a mass fraction of 0.25, 0.5 or 0.75. The basicity, acid neutralization and physical properties of the CPC-Ca3SiO5 composites were investigated. Mineral trioxide aggregate (MTA) was used as the control. The acid neutralizing capacity of the CPC-Ca3SiO5 composites and MTA were measured by titrating the suspensions of ground set samples with a 0.2 mol / L HCl at predetermined pH levels, i.e., 11, 9.0, and 7.4. The setting time of CPC-Ca3SiO5 composites determined by the Gilmore needle method was 40 ± 10 min. Acid neutralizing capacity of CPC depended (p < 0.05) on Ca3SiO5 content. CPC containing 75 % Ca3SiO5 could neutralize slightly less acid than MTA (p < 0.05), but it had a shorter setting time than that of MTA (> 4 h) and excellent handling properties.

Tissue engineering offers immense promise for bone regeneration. Human umbilical cord mesenchymal stem cells (hUCMSCs) can be collected without invasive procedures required for bone marrow MSCs. The objective of this study was to investigate the physical properties and the differentiation capacity of hUCMSCs on calcium phosphate cement (CPC) scaffolds with improved dissolution/resorption rates. CPC consisted of tetracalcium phosphate and dicalcium phosphate anhydrous, with various tetracalcium phosphate/dicalcium phosphate anhydrous ratios. At 1/3 ratio, CPC had a dissolution rate 40% faster than CPC control at 1/1. The faster-resorbable CPC had strength and modulus similar to CPC control. Their strength and modulus exceeded the reported values for cancellous bone, and were much higher than those of hydrogels and injectable polymers for cell delivery. hUCMSCs attached to the nano-apatitic CPC and proliferated rapidly. hUCMSCs differentiated into the osteogenic lineage, with significant increases in alkaline phosphatase activity, osteocalcin, collagen I, and osterix gene expression. In conclusion, in this study we reported that hUCMSCs attaching to CPC with high dissolution/resorption rate showed excellent proliferation and osteogenic differentiation. hUCMSCs delivered via high-strength CPC have the potential to be an inexhaustible and low-cost alternative to the gold-standard human bone marrow mesenchymal stem cells. These results may broadly impact stem-cell-based tissue engineering.

Objective: A sequential topical application of calcium and fluoride-phosphate solutions was reported to occlude open dentin tubules, mainly with fluoroapatite precipitates by a rapid ionic reaction, and to be effective at treating dentin hypersensitivity. However, its ability to reduce dentin permeability (Lp) is unknown. The aim of this in vitro study was to evaluate the effect of this treatment on Lp., Methods: Nine extracted human third molars were sectioned transversely to obtain 0.5 mm-thick discs, which were then etched and rinsed. Aqueous solutions of 5% (w/w) disodium phosphate containing 0.3% (w/w) sodium fluoride (A) and 10% (w/w) calcium chloride (B) were prepared. The sequential application of the A&B solutions was repeated three times on each disc, which was then rinsed with distilled water. The Lp of the discs was measured before and after the application using a modified Pashley's fluid flow measuring system. The differences in the Lp values between the conditions before and after the solution applications were analysed using a generalized estimating equation method and paired t-test. Scanning Electron Microscopy (SEM) was used to observe the dentin surfaces., Results: All nine discs consistently indicated reduced Lp following the application of the A&B solutions. There was a significant decrease in the mean Lp [microL/(cm(2) s cm H(2)O)] from baseline (-0.27+/-0.25, p=0.011). Overall, an average decrease of 34% Lp occurred after the application of the A&B solutions. SEM observation indicated that the reaction products covered the entire dentin disc surface., Conclusion: The application of the A&B solutions was effective at reducing the Lp of the dentin discs., (Published by Elsevier Ltd.)

The osteoconductive and possibly osteoinductive characteristics of OCP increased the interest in preparation of bone graft materials that contain OCP in its composition. Calcium phosphate cements (CPCs) were prepared using a mixture of α-tricalcium phosphate (α-TCP) and dicalcium phosphate anhydrous (DCPA), with α-TCP / DCPA molar ratio of 1/1 and distilled water or 0.5 mol / L phosphate aqueous solution (pH = 6.1 ± 0.1) as the cement liquid. Hardening time was (30 ± 1) min for the CPC mixed with water and (5 ± 1) min for the CPC mixed with phosphate solution. Diametral tensile strength (DTS), porosity (P), and phase composition (powder x-ray diffraction) were determined after the hardened specimens had been immersed in a physiological-like solution (PLS) for 1 d, 3 d, and 7 d. In CPC specimens prepared with water, calcium hydroxyapatite (HA) was formed and DTS and P were (9.03 ± 0.48) MPa and (37.05 ± 0.20) vol % after 1 d, respectively, and (9.15 ± 0.45) MPa and (37.24 ± 0.63) vol % after 3 d, respectively. In CPC specimens prepared with phosphate solution OCP and HA were formed and DTS and P were (4.38 ± 0.49) MPa and (41.44 ± 1.25) vol % after 1 d, respectively,(4.38 ± 0.29) MPa and (42.52 ± 2.15) vol % after 3 d, respectively, and (4.30 ± 0.60) MPa and (41.38 ± 1.65) vol % after 7 d, respectively. For each group DTS and P did not change with PLS immersion time. DTS was significantly higher and P was significantly lower for CPCs prepared with water. HA formation slightly increased with immersion time from 40 mass % after 1 d to 50 mass % after 3 d in CPCs prepared with water. OCP + HA formation increased with immersion time from 30 mass % after 1 d to 35 mass % after 3 d and to 45 mass % after 7 d in CPCs prepared with 0.5 mol / L phosphate solution.

Secondary caries and restoration fracture remain common problems in dentistry. This study tested the hypothesis that combining nano-CaF(2) and glass fillers would yield nanocomposites with high mechanical properties and F release. Novel CaF(2) nanoparticles (56-nm) were synthesized via spray-drying and incorporated into resin. F release increased with increasing the nano-CaF(2) content, or with decreasing pH (p < 0.05). F-release rates at 70-84 days were 1.13 microg/(cm(2) x day) and 0.50 microg/(cm(2) x day) for nanocomposites containing 30% and 20% nano-CaF(2), respectively. They matched the 0.65 microg/(cm(2) x day) of resin-modified glass ionomer (p > 0.1). The nanocomposites had flexural strengths of 70-120 MPa, after 84-day immersion at pH 4, pH 5.5, and pH 7. These strengths were nearly three-fold that of resin-modified glass ionomer, and matched/exceeded a composite with little F release. In summary, novel CaF(2) nanoparticles produced high F release at low filler levels, thereby making room in resin for reinforcement glass. This yielded nanocomposites with high F-release and stress-bearing properties, which may help reduce secondary caries and restoration fracture.

The bone defect repair functions of calcium phosphate cement (CPC) are related to its osteoconductivity and its gradual replacement by new bone. Adding mannitol to CPC may enhance its bone repair potential by increasing CPCs macroporosity and dissolution rate. The objective of the study was to assess microporosity and macroporosity and dissolution rates for CPC mixed with mannitol. Three groups of CPC discs were prepared by combining an equimolar mixture of tetracalcium phosphate and anhydrous dicalcium phosphate with (0 %, 10 %, or 50 %) mass fraction (hereafter expressed as mass %) of mannitol. Macroporosity and microporosity of the samples were calculated from volume and mass measurements of the discs. Discs were then placed in a pH 3.0 demineralizing solution simulating acidified physiological solution, and dissolution rates were measured by a previously described constant-composition titration method. Pure CPC exhibited no macropores and microporosity (mean ± s.d.; n = 5) of (46.8 ± 0.8) % volume fraction (hereafter expressed as vol %). Adding 10 mass % mannitol resulted in 15.6 ± 3.9 vol % macroporosity and 39.4 ± 1.8 vol % microporosity, and adding 50 mass % mannitol produced 54.7 ± 0.8 vol % macroporosity and 21.1 ± 0.4 vol % microporosity. The dissolution rates (mean ± s.d.; n = 5) of CPC with (0, 10, and 50) mass % mannitol incorporation were (30.6 ± 3.4, 44.8 ± 10.2, and 54.7 ± 3.6, respectively) μg · cm(-2) · min(-1), or (0.018 ± 0.002, 0.032 ± 0.007, and 0.072 ± 0.005, respectively) μL · cm(-2) · min(-1). Adding either 10 mass % or 50 mass % mannitol into CPC significantly (p < 0.05) increased CPC dissolution rates. Adding mannitol readily increased macroporosity and dissolution rate of CPC, which may enhance the capacity of CPC to be osteoconductive.

This study aimed at preparing and studying the properties of nanoparticles of calcium phosphate (nCaP) with Ca/P ratios ranging from 1.0 to 1.67 using a spray-drying technique. Micro-structural analyses suggested that the nCaPs with Ca/P ratios of 1.67 to 1.33 were nano-sized amorphous calcium phosphate (ACP) containing varying amounts of acid phosphate and carbonate. The nCaP with Ca/P ratio of 1 contained only nano-sized low crystalline dicalcium phosphate (DCP). BET measurements of the nCaPs showed specific surface areas of (12 ± 2 to 50 ± 1) m(2)/g, corresponding to estimated equivalent spherical diameters of (38 to 172) nm. However, dynamic light scattering measurements revealed much larger particles of (380 ± 49 to 768 ± 111) nm, owing to agglomeration of the smaller primary nano particles as revealed by Scanning Electron Microscopy (SEM). Thermodynamic solubility measurements showed that the nCaPs with Ca/P ratio of 1.33 - 1.67 all have similar solubility behavior. The materials were more soluble than the crystalline hydroxyapatite (HA) at pH greater than about 4.7, and more soluble than β-tricalcium phosphate (β-TCP), octacalcium phosphate (OCP) and DCP at pH above 5.5. Their solubility approached that of α-tricalcium phosphate (α-TCP) at about pH 7. These nCaPs, which cannot be readily prepared by other currently available methods for nanoparticle preparation, have potential biomedical applications.

This study reports for the first time in vitro and in vivo properties of fluorapatite (FA)-forming calcium phosphate cements (CPCs). The experimental cements contained from (0 to 3.1) mass % of F, corresponding to presence of FA at levels of approximately (0 to 87) mass %. The crystallinity of the apatitic cement product increased greatly with the FA content. When implanted subcutaneously in rats, the in vivo resorption rate decreased significantly with increasing FA content. The cement with the highest FA content was not resorbed in soft tissue, making it the first known biocompatible and bioinert CPC. These bioinert CPCs might be useful for applications where slow or no resorption of the implant is required to achieve the desired clinical outcome.

Diffusion-controlled dissolution and precipitation reactions occur in many biological systems and some non-stirred in vitro systems. Previous studies have shown that differences in the diffusion rates of the ions involved in a dissolution/precipitation reaction can produce significant effects on the rate and course of the reaction. We report here results of a study that show inter-diffusion of ions between two solutions, both saturated with respect to hydroxyapatite but with dissimilar compositions, resulted in one solution becoming undersaturated and the other supersaturated. A model is proposed that may explain the formation of a mineral-dense layer in the caries process.

Previous studies showed that water-free, premixed calcium phosphate cements (Pre-CPCs) exhibited longer hardening times and lower strengths than conventional CPCs, but were stable in the package. The materials hardened only after being delivered to a wet environment and formed hydroxyapatite as the only product. Pre-CPCs also demonstrated good washout resistance and excellent biocompatibility when implanted in subcutaneous tissues in rats. The present study evaluated characteristics of Pre-CPCs when implanted in subcutaneous tissues (Study I) and used for repairing surgically created two-wall periodontal defects (Study II). Pre-CPC pastes were prepared by combining CPC powders that consisted of CPC-1: Ca(4)(PO(4))(2)O and CaHPO(4), CPC-2: α-Ca(3)(PO(4))(2) and CaCO(3) or CPC-3: DCPA and Ca(OH)(2) with a glycerol at powder-to-liquid mass ratios of 3.5, 2.5, and 2.5, respectively. In each cement mixture, the Ca to P molar ratio was 1.67. The glycerol contained Na(2)HPO(4) (30 mass %) and hydroxypropyl methylcellulose (0.55 %) to accelerate cement hardening and improve washout resistance, respectively. In Study I, the test materials were implanted subcutaneously in rats. Four weeks after the operation, the animals were sacrificed and histopathological observations were performed. The results showed that all of the implanted materials exhibited very slight or negligible inflammatory reactions in tissues contacted with the implants. In Study II, the mandibular premolar teeth of mature beagle dogs were extracted. One month later, two-wall periodontal bone defects were surgically created adjacent to the teeth of the mandibular bone. The defects were filled with the Pre-CPC pastes and the flaps replaced in the preoperative position. The dogs were sacrificed at 1, 3 and 6 months after surgery and sections of filled defects resected. Results showed that one month after surgery, the implanted Pre-CPC-1 paste was partially replaced by bone and was converted to bone at 6 months. The pockets filled with Pre-CPC-2 were completely covered by newly formed bone in 1 month. The Pre-CPC-2 was partially replaced by trabecular bone in 1 month and was completely replaced by bone in 6 months. Examination of 1 month and 3 month samples indicated that Pre-CPC-2 resorbed and was replaced by bone more rapidly than Pre-CPC 1. Both Pre-CPC pastes were highly osteoconductive. When implanted in periodontal defects, Pre-CPC-2 was replaced by bone more rapidly than Pre-CPC-1.