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Актуальность. Резистентность зубов к кариесу может быть связана с морфологическим строением эмали, обусловливающим изменение ее основных свойств (кислотоустойчивость, проницаемость, микротвердость). Среди множества характеристик структуры эмали, влияющих на уровень ее кариесрезистентности, выделяют качество минерализации. На минерализацию органического костного матрикса, коллагенообразование, функциональное состояние костных клеток, обмен витамина D, а также на рост кристалла гидроксиапатита непосредственно влияет магний. С физиологической точки зрения до 53 % магния концентрируется в костной ткани, дентине и эмали зубов. Магнию принадлежит существенная роль в формировании нормальной структуры соединительной ткани, и одним из этиологических факторов формирования дисплазии соединительной ткани является нарушение его гомеостаза. Цель исследования: определить содержание минеральных компонентов в ротовой жидкости у детей с синдромом недифференцированной дисплазии соединительной ткани и выявить их взаимосвязь с показателями кариесрезистентности эмали зубов. Материалы и методы. Осмотрено 50 детей в возрасте 10–12 лет. С помощью биохимических исследований определяли содержание концентрации кальция и магния в ротовой жидкости. Кариесрезистентность эмали зубов определяли с помощью теста эмалевой резистентности по В.Р. Окушко. Статистическая обработка данных проводилась с помощью пакетов Statistica 6.0 и StatPlus 5.9. Дети были разделены на две группы: группа I — основная (с синдромом недифференцированной дисплазии соединительной ткани, 30 человек) и группа II — контрольная (условно здоровые дети, с высокой кариесрезистентностью, 20 человек). Результаты. Средние результаты минеральных компонентов были гораздо ниже в основной группе, чем в контрольной: концентрация Са составила 0,88 и 1,23 ммоль/л соответственно, а Mg — 0,25 и 0,44 ммоль/л. Средние результаты теста эмалевой резистентности составили 5,83 и 4,15 балла в основной и контрольной группах соответственно. Показатели концентрации кальция в ротовой жидкости основной группы по сравнению с контрольной снижены на 28,5 %, а содержание магния меньше на 43,2 %. Данные теста эмалевой резистентности показали, что результаты в основной группе на 28,8 % ниже, чем в контрольной. Заключение. В основной группе концентрация Са и Mg в дефиците, и дети этой группы нуждаются в коррекции содержания указанных микроэлементов. Недостаточное количество содержания кальция и магния в организме ребенка приводит к нарушению строения эмали, что негативно отражается на кариес­устойчивости эмали зубов.

This study presents a novel tool to predict temperature-exposure of incinerated pig teeth as a proxy for understanding impacts of fire on human teeth. Previous studies on the estimation of temperature-exposure of skeletal elements have been limited to that of heat-exposed bone. This predictive tool was developed using a multinomial regression model of colourimetric and hydroxyapatite crystal size variables using data obtained from unheated pig teeth and teeth incinerated at 300 °C, 600 °C, 800 °C and 1000 °C. An additional variable based on the observed appearance of the tooth was included in the tool. This enables the tooth to be classified as definitely burnt (600 °C–1000 °C) or uncertain (27 °C/300 °C). As a result, the model predicting the temperature-exposure of the incinerated teeth had an accuracy of 95%. This tool is a holistic, robust and reliable approach to estimate temperature of heat-exposed pig teeth, with high accuracy, and may act as a valuable proxy to estimate heat exposure for human teeth in forensic casework.

Hydroxyapatite crystal deposition disease (HADD) around the hip is typically described involving the gluteal tendons. However, HADD can occur in any location and result in varied clinical presentations. Even with small deposits, symptoms can be significant and imaging findings may appear aggressive, mimicking infection and malignancy particularly when in an atypical location.We illustrate cases of both common and rare locations of HADD around the hip, in particular presenting as greater trochanteric pain syndrome, piriformis syndrome and ischiofemoral impingement. The latter two manifestations have not been previously described in the literature.Low signal deposits were identified on MRI at the greater trochanter (gluteus medius tendon), proximal piriformis (adjacent to the sciatic nerve), and quadratus femoris (in the ischiofemoral space), respectively. Associated inflammatory changes with tendinopathy, bursitis and oedema were also demonstrated. The patient with piriformis syndrome underwent steroid injections and shockwave therapy with significant symptom improvement.HADD should be within the differential diagnosis for hip pain and nerve compression syndromes. Knowledge of tendon anatomy and correlation with radiographs or CT, even after MRI, is crucial in recognising unusual manifestations and preventing unnecessary investigation. Therefore, we review the spectrum of imaging features of HADD, as well as the current evidence on its management, to confidently diagnose this condition.

Hydroxyapatite crystal deposition disease and its pathophysiology are poorly understood; however, it is known that calcific tendinitis is the most common condition related to this deposition in the upper limb. Movement of the crystals toward the myotendinous junction is rare; to the best of our knowledge, only 19 cases have been described in the literature, one of which was a case of intramuscular deposition without migration. The purpose of this technical note is to describe the technical details of the arthroscopic treatment of intramuscular calcium hydroxyapatite deposits without intratendinous migration.

Hydroxyapatite crystal deposition diseases (HADDs) are characterized by deposition of insoluble crystals within the joints and periarticular soft tissues, initiating inflammatory destructive reaction. Calcium hydroxyapatite (CHA) is the most common type of calcium in human bone and is also the most common pathologic calcification found in the body. There are three phases of the disease: silent, mechanical, and adhesive phases. The shoulder is the most common site of HADD. CHA crystals are non-birefringent in polarized light. Radiographic characteristics include homogenous, amorphous densities without trabeculations that are variable in size, ovoid, triangular, or linear. The first imaging modalities to identify calcific tendinitis (CT) were X-ray and ultrasound, as calcium deposits are readily identifiable on both. Treatment is chiefly conservative, including nonsteroidal anti-inflammatory drugs (NSAIDs), local heat application, and physiotherapy. Local corticosteroid injections may also be of benefit. When intra-articular, CHA crystals can cause joint destruction such as “ Milwaukee shoulder.” In the acute symptomatic phase of HADD, called acute calcific periarthritis, soft tissue and osseous edema can be present and needs to be differentiated from infection, tumor, and trauma.

A hydroxyapatite (HAP)/silk fibroin (SF) bone-like biomaterial was fabricated through a coprecipitation process using stepped temperatures. We evaluated the effect of increasing temperatures on hydroxyapatite crystal arrangement on a silk fibroin surface. We found that the HAP crystal particles self-assembled on the silk fibroin surface. Further we found that with rising temperature the HAP crystal c-axis became progressively more parallel to the long axis of the silk fibroin. This deposition pattern is similar to that seen with HAP and collagen assembly in normal bone. Based on the XRD, SEM, and TEM results, we conclude that higher temperatures promote crystal nucleation resulting in an increase in both HAP crystal size and HAP/SF particle size. These data support the use of HAP/SF bone-like biomaterials for bone replacement and regeneration.

This study aimed to investigate whether Pb nanoparticle exposure affects the bone calcium sensing receptor (CaSR), hydroxyapatite crystal, and receptor activator of nuclear factor-kappa B (RANK) in rats exposed to subchronic and chronic inhalation. Thirty two rats were randomly divided into eight groups. One group is a non-exposed group. While three groups were exposed to nanoparticles Pb at the following doses 6.25; 12.5; or 25 mg/m3 an hour daily for 28 days. Another three groups were exposed to nanoparticles Pb at following doses 6.25; 12.5; and 25 mg/m3 one hour daily for 6 months. The expression of trabecular CaSR was significantly decreased at the all doses subchronic exposure compared to the control group (P < 0.05). The CaSR expression significantly decreased in second and third doses subchronic exposure groups compared to the control groups (P < 0.05). With subchronic exposure, the crystal size was increased in second dose group and decreased in lowest and highest doses compared to the control (untreated) group. The crystal size and c-axis were decreased in all dose chronic exposures compared to the control (untreated) group. The expression of cortical RANK was significantly lower at the two lowest dose chronic exposures compared to the control group (P < 0.05). In conclusion, Pb nanoparticle inhibit hydroxyapatite crystal growth at least a part via down regulation of CaSR and RANK. [Med-Science 2017; 6(1.000): 46-50]

To calrify the combined effect of soft template and biominormolecule on the formation of hydroxyapatite (HAp), the study on the growth of HAp regulated by citrate and(or) hexadecyltrimethylammonium bromide (CTAB) solution was developed in a thermal aqueous. The as-obtained products were characterized by XRD, FT-IR and TEM, altogether with HRTEM and ED. Plate-like HAp crystals in nanosize with relative weak crystallinity were obtained in the presence of citrate. Nano-needle shape HAp crystals were produced in the presence of CTAB. Rod-like HAp crystals in a uniform nanosize were formed under the regulation of CTAB and citrate, which showed the same orientation as that of CTAB only. However, the possible mechanism of the growth of HAp was discussed in detail. CTAB micelles worked as a soft template modified by citrate, which guided to form HAp crystals in different morphology. The study is benefit to control the formation of HAp for its bioapplication.

Modifikasi kristal hidroksiapatit yang sudah dihasilkan Balai Besar Keramik (BBK) dengan kalsium karbonat dan magnesium karbonat dilakukan dengan metode drymechanochemical . Metode ini hanya memanfaatkan energi kecil yang dihasilkan dari giling mekanik. Campuran digiling kering kemudian dikarakterisasi dengan X-Ray Diffraction ( XRD ). Puncak kalsium karbonat masih terbentuk dari hasil XRD karena ikatannya sangat kuat sehingga tidak dapat masuk ke dalam kristal hidroksiapatit. Modifikasi dengan magnesium karbonat menunjukkan bahwa ada puncak MgO, dimana ikatan antara magnesium dan karbonat terpecah. Variasi waktu giling dilakukan dari 12, 24, 36, dan 48 jam. Didapatkan bahwa pada waktu giling 48 jam, ikatan magnesium karbonat lepas secara optimum dilihat dari puncak XRD yang terbentuk. Kata Kunci: hidroksiapatit, x-ray diffraction, drymechanochemical

The structure of hydroxyapatite plasma coatings on a titanium substrate has been investigated by the X-ray Rietveld method. The hydroxyapatite crystal structure in plasma-deposited samples is characterized by strong distortions of its main element (tetrahedral PO4 cluster) and coordination calcium polyhedra, as well as calcium deficit in the Ca2 site; however, these features do not change the main motif of the hydroxyapatite structure. The bond distortions in PO4 clusters are estimated by the Bauer method. It is shown that hydrothermal treatment leads to the almost complete recovery of the hydroxyapatite structure.

Hydroxyapatite is a common material applied in orthophedia and dentistry. The application of this material is currently expanded to biotechnology field, such as to be used as support materials for enzymes immobilization. Hydroxyapatite can be synthesized by utilizing chicken eggshell waste in household and food industries. This work is aiming to provide a simple and easy method to synthesize hydroxyapatite from chicken eggshell. The synthesis of hydroxyapatite was firstly carried out by reacting chicken eggshell powder (calcium precursor) with (NH4)2HPO4via modified precipitation at room temperature and normal atmospheric pressure. The mixture was then stirred variably for 1, 2, 3, and 24 hours. X-ray diffraction (XRD) analysis suggests that hydroxyapatite powder derived from this procedure formed a single-phase crystal and it was completely formed after the reaction has run for 1 hour. The scanning electron microscopy (SEM) image showed that the synthesized hydroxyapatite forms a rice-like pattern. The size of hydroxyapatite crystal measured at (002) plane was about 45 nm. Our result showed that simple modified precipitation at room temperature and normal atmospheric pressure in one hour reaction has successfully synthesized hydroxyapatite from chicken eggshell.

The aim of this study is to induce bone from immature muscular tissuein vitrousing recombinant human BMP (rhBMP)-2 and expanded polytetrafluoroethylene (ePTFE) as a scaffold. Commercially available rhBMP-2 was used in this experiment. IMTs were harvested from the forelimbs of 20th Sprague-Dawley embryonic rats and placed into a homogenizer with 10ng/μl of rhBMP-2 and then homogenized. The homogenized IMT was placed on ePTFE and cultured for 2 weeks. The analyses of histological observation, electron probe micro analyzer (EPMA), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) were carried out following culture. The bone-like tissue, which was made up of osteoblast-like cells and osteoids, was partially observed by H-E staining. Moreover, strong mineral deposition was observed in the extracellular matrix by von Kossa staining. Ca, P and O were detected in the extracellular matrix by EPMA and were confirmed to be at almost the same position based on the findings of synchronized images. XRD patterns and FTIR spectra of specimen were found to have typical hydroxyapatite crystal peaks and spectra, respectively. These results suggest that rhBMP-2 induced IMT differentiation into bone-like tissuein vitro.

We presented a case in which massive hydroxyapatite accumulation was observed around the artificial hip joint. A 66-year-old female showed a massive accumulation of fluid in and around the hip joint, and milk-like aspirate was obtained. Her aspirate culture was negative, and sediment analysis by X-ray diffraction showed that its component was hydroxyapatite. Since pain was mild, the patient was treated conservatively. To our knowledge, this is the first case in which liquid hydroxyapatite (milk of calcium) was accumulated around the artificial hip joint.

Teeth having open apices in the absence of a natural apical constriction pose several challenges during conventional endodontic treatment, especially when establishing an apical seal. Treatment is further challenging when these teeth are associated with large periapical or cystic lesions having resulted in expansion and/or thinning of adjacent cortical plates. Although surgical intervention is commonly adopted in the management of such cases, a conservative treatment option offering equally good prognosis is always desirable. This case series describes 3 cases: a 39-year-old woman, a 45-year-old woman, and a 15-year-old boy having teeth with concomitant open apices and large periapical/cystic lesions managed conservatively by (1) following a strict intracanal disinfection protocol, (2) intracanal aspiration with digital decompression of associated swelling, and (3) 1-step apexification for closure of the root apex by placing a preliminary barrier of platelet-rich fibrin (PRF) and a secondary barrier of Biodentine (Septodont, Saint-Maur-des-Fosses, France). In all 3 cases, the treatment outcomes, both clinical and radiographic, were highly satisfactory. PRF and Biodentine collectively rendered an apical plug that proved to be a suitable alternative to commonly used mineral trioxide aggregate in 1-step apexification. Biodentine provides good interfacial adhesion and sealing with dentin attributed to its property of hydroxyapatite crystal deposition at the material-dentin interface. Also, because of its bioactivity, it likely promotes the conversion of adjacent PRF into a calcific barrier, thus reinforcing the apical seal. Additionally, host-modulating responses of PRF contribute in expediting the healing process. Reasonable osseous healing in the periapex could be appreciated as early as 3 months in all patients. The rapidity with which healing occurred may have been an incidental finding but definitely draws attention.

Acute calcific tendinopathy is one of the manifestations of hydroxyapatite crystal deposition disease. While it is more frequent in the shoulder, it has been described in virtually all areas of the body, but rarely in the muscles of the hand. Its etiopathogenesis is not yet fully understood and despite being a fairly frequent condition, it is commonly misdiagnosed. The onset of the disease is usually acute and resolves spontaneously. Acute calcific tendinitis of the interosseous tendons of the hand is an uncommon site of a frequent condition. The clinical presentation is similar to other entities, thus errors in diagnosis frequently occur, resulting in over-treatment or unnecessary tests. We describe a case of acute calcific tendinitis of the interosseous muscles of the hand with a brief review of the current literature with emphasis on diagnostic imaging methods.

Destructive arthropathy of the hip joint can be attributed to various etiologies like rheumatoid arthritis, aseptic necrosis of the femur head, Charcot's joint, subacute septic arthritis, and tubercular arthritis. A disease that results in much rapid destruction of the hip joint and is not associated with clinical syndrome of above mentioned disease has been reported way back in 1970. However, no evidence-based study has been published to support hydroxyapatite (HA) crystals as a probable cause of rapidly destructive arthropathy of the hip joint. We report a case with microscopic and biochemical confirmation of HA crystal deposition causing destructive arthropathy of the hip joint.

Nanorod and needle-like hydroxyapatite (HAp) crystals were successfully synthesized at 85 degrees C through a simple and mild pathway. Single-phase HAp powder with high crystallinity was obtained without thermal treatment. The effect of urea concentration on the crystal component was investigated. X-ray diffraction (XRD) results indicated that pH adjustment played a key role in controlling the composition of final products. The fast adjustment on pH by NH(3)center dot H(2)O resulted in formation of single-phase HAp with nanorod and needle-like shapes while the slow adjustment by urea led to a mixture of octacalcium phosphate (OCP) and HAp with ribbon-like morphology. Ribbon-like OCP crystal was the intermediate for the transformation from monetite (DCPA) to HAp. (C) 2009 Elsevier B.V. All rights reserved.

Rare earth ion-doped hydroxyapatite (Ln-doped HAp) samples were prepared in order to make clear the behavior of rare earth (Ln) ions living body system. Photoluminescence (PL) spectra of hydroxyapatite (HAp) had no emission peak, and that of Ln-doped HAp samples had a lot of emission peaks due to f - f electron transition of Ln3+. The emission peak intensity of fired Ln-doped HAp samples is higher than that of unfired Ln-doped HAp samples. These XRD traces of the unfired samples are similar to that of HAp, while XRD traces of the fired samples were observed that the diffraction angle of all peaks shifts to higher with an increase in the concentration of rare earth ion in each aqueous solution. These results suggest that trivalent rare earth ions are substituted for Ca2+ ion in HAp crystals.

Homogeneous coatings adhered strongly to titanium substrates were attained by electrochemical method in electrolytes containing Ca2+ and PO4 3- ions with Ca/P ratio being 1.67. SEM observation showed that the HAp crystals prepared with higher concentration electrolyte (4x10-2M Ca2+) are ribbon-like with thickness of nanometer size, a morphology seldom reported previously. In an electrolyte of lower concentration (6x10-4M Ca2+), the HAp crystals formed are rod-like with defined hexagonal cross section and diameter of about 70-80nm. The electrolyte of intermediary concentration (5x10-3M Ca2+) produced plate-like HAp crystals. XRD patterns and IR spectra confirmed that the coatings consist of HAp crystals.

Pathologic deposition of mineral in the form of bone-like hydroxyapatite is a frequent occurrence in juvenile dermatomyositis (JDM) and other connective tissue diseases. Although the sizes of the mineral crystals in JDM are similar to those in bone, there is much more mineral in the deposits than there is in bone. Bone matrix proteins also accumulate associated with the deposits. The reasons for the formation of these deposits are not known. It is our hypothesis that persistent inflammation is a component of JDM and other hydroxyapatite deposition diseases. Other contributing factors are genetic, environmental, and physical chemical. This paper discusses the influence of inflammation on the deposition of hydroxyapatite, with emphasis on the clinical and environmental factors that may facilitate the formation of calcific deposits in JDM.

Dental decay is the most widespread and prevalent disease plaguing humankind. Fluoride has been the dominant anti-cavity therapy until the discovery that theobromine, an extract from chocolate, could re-mineralize enamel better than fluoride at 71-times lower concentrations. Theobromine is also safe to swallow, unlike toxic fluoride, so this discovery could revolutionize the oral care industry, which has not innovated in over a century. In this work, we will look at theobromine's effect on enamel's structure and function by looking at studies that point to larger hydroxyapatite crystal growth and improved surface micro-hardness of enamel. The studies presented here offer an exciting look into an innovative, natural and more efficacious technology in the oral care market that is from one of mankind's most beloved foods: chocolate.