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Bioceramics are a fast-growing materials group, which are widely used in orthopedics, maxillofacial, dental, and reconstructive surgeries. They are produced using raw materials either from synthetic or natural sources. As naturally originated resources, the bones of sheep and cows are used after converting to calcium phosphates. Human-originated sources in the past were obtained from human cadaver bones, however now-a-days this has been discontinued. On the other hand, the “golden standard” in the reconstruction surgery has been using patients own bones, -i.e., autogenous bones, which heal better than other alternatives. Besides natural products, synthetic materials are produced from a range of inorganic raw and natural materials based on marine sources, such as corals, and other marine-derived materials (i.e., seashells, nacre). These are used to produce bioceramics and hence implants, devices, and bone grafts. Although during the last four decades a number of excellent books and book chapters have been published, no comprehensive review has been yet reported to cover the available marine materials and to indicate the related work and corresponding references to allow for both medical and ceramic scientists to access directly and open new avenues for further research on marine structures and their applications in orthopedic, maxillofacial, and reconstructive surgery areas. Hence, this review covers the general marine structures, their locations and availability in different countries and, current research on production methods of these unique structures that are difficult to fabricate synthetically. The authors are confident that this comprehensive review will be an excellent source not only for the ceramists, but also for the medical scientists.

Bracket failure is one of the most important problems encountered during fixed orthodontic treatment. For this reason, different types of adhesive agents have been developed over the years. Consequently, the aim of this study was to evaluate the shear bond strength of brackets bonded to teeth etched with a conventional acid etching method in a laboratory environment by using different types of adhesive agents and comparing the number of shear strokes. Sixty human maxillary premolars were divided into three groups and Gemini stainless steel metal brackets (3M Unitek, Monrovia, CA, USA) were bonded to all teeth. In Group 1, Transbond™ XT Primer (3M Unitek, Monrovia, CA, USA) and Transbond™ XT Light Cure Adhesive Paste composite (3M Unitek, Monrovia, CA, USA) were used. In Group 2, BracePaste® MTP Primer (American Orthodontics, Sheboygan, CA, USA) and BracePaste® Adhesive composite (American Orthodontics, Sheboygan, WI, USA) were used. In Group 3, Ortho Solo™ Primer (Ormco, Orange, CA, USA) and Grengloo™ Adhesive composite (Ormco, Brea, CA, USA) were used. The samples were subjected to a shear test with a closed-loop controlled, low-cycle fatigue machine with a capacity of 10 N and a crosshead speed of 300 mm/min. The number of shear strokes of the brackets was recorded. According to the Kruskal–Wallis and Mann–Whitney U tests performed on the data obtained, statistically significant differences were found between the groups in terms of the numbers of shear strokes (p < 0.05). Significantly higher numbers of shear strokes and higher shear bond strengths were observed in Group 3 compared with Group 1 and Group 2 (p < 0.05). There was no statistically significant difference between the numbers of shear strokes for Group 1 and Group 2 samples (p > 0.05). To conclude the study, it was observed that the type of adhesive used had an effect on the bond strength of the bracket and that the Grengloo™ adhesive agent showed higher shear bond strength. It was observed that BracePaste® Adhesive and Transbond™ XT Light Cure Adhesive Paste adhesive agents had similar shear bond strengths.

The aim of this study is to obtain pure natural hydroxyapatite (HAp) and tricalcium phosphate (TCP) from a Goniopora spp. and from hump coral (Porites cylindrica), both sourced from Australia. Due to the nature of the conversion process, commercial coralline HAp has retained coral or CaCO3, and the structure possesses both nano- and mesopores within the interpore trabeculae resulting in high dissolution rates. To overcome these limitations, a newly patented coral double-conversion technique has been developed. The current technique involves a two-stage application route where in the first-stage complete conversion of coral to pure HAp is achieved. In the second stage, a sol-gel-derived HAp nanocoating is directly applied to cover the meso- and nanopores within the intrapore material, while maintaining the large pores. Here, we specifically investigated the morphological changes and characterized these corals prior to and after conversion. For this purpose, four groups designated as C0, C1, C2, and C3 were used. C0 is Porites, Goniopora, and cylindrica; the original coral is calcium carbonate with aragonite structure that contains proteins and polysaccharides. C1 is coral cleaned under ultrasound in bleach diluted with water. C2 is coral converted to hydroxyapatite (HAp) by hydrothermal treatment method at 200 °C under pressure in the presence of ammonium biphosphate. C3 is obtained by coating C2 with sol-gel alkoxide-derived nanohydroxyapatite to obtain a more bioactive osteoconductive material and improve mechanical properties. All groups were characterized by XRD, EDAX, DTA/TGA, and SEM. The results showed that the biaxial strengths of the C2 and C3 were significantly higher than the original coral. The work also showed the advantages of the hydrothermal conversion method and the effect of the nanocoating which is expected to improve the final bioactivity through microstructural changes of the surfaces. © 2019, Australian Ceramic Society.

In this study, sintering effects on microstructural behavior of bovine derived hydroxyapatite doped with powder mullite are considered in the temperature range between 1000 °C and 1300 °C. Results show that maximum values of both compressive strength and microhardness are achieved in the samples sintered at 1200 °C for all mullite additions of 5, 7.5, 10 and 12.5 wt%. Moreover, above 1000 °C, decomposition of HA and new phase formations such as whitlockite and gehlenite play a major role in both compressive strength and microhardness properties which increase up to 10 wt% mullite reinforcement. © 2017 Elsevier B.V.

Based on the development of many adhesive systems and bonding techniques, bonding strength of orthodontic brackets has become even more important in modern clinical orthodontics. The aim of this study was to determine mean shearing stroke frequency of different orthodontic bracket types and bonding agents under cycling loading. Therefore, 10 different types of orthodontic bracket from 4 different brands were divided into 2 groups. Two different adhesives, namely Transbond&trade, XT etch-and-rinse for Group 1 and Transbond&trade, Plus self-etching-primer adhesive for Group 2 were considered. The brackets were tested under cycling loading force of 10-N and a crosshead speed of 300 mm/min and 40 cycle/min. The frequency of strokes that the brackets failed were determined and these data were analyzed by statistical analysis using an independent sample t-test and one-way analysis of variance (ANOVA). The level of significance was set at p &lt, 0.05. Generally, differences between the frequency of shearing strokes of the bracket failures were found to be statistically significant depending on the type of adhesives and brackets (p &lt, 0.05). The bonding technique for Group 1 was found to have a significantly higher shear bonding strength than Group 2. It is also seen that different types of bracket belonging to the same or different brands had different shear bonding strength. It may be concluded that: (i) all bracket types used in this study can be applied with both bonding techniques, (ii) in order to minimize the risk of hard tissue damage, ceramic brackets should be carefully bonded using the self-etching primary adhesive technique.

Tendo kopukları çoğunlukla ekstremitelerin distal kısımlarında meydana gelmekte ve uzun süreli bir iyileşme periyodu gerektirmektedir. Travmatik aşil tendo kopuklarında operasyon öncesi ve sonrasını da kapsayan 6 -8 haftalık bir bandaj uygulaması ile hareketsizlik sağlanmaktadır. Bu uygulamanın neden olacağı diğer ortopedik problemleri önlemek ve iyileşme periyodunu hızlandırabilmek amacıyla, operasyon sonrası lokal uygulamalar yapılmaktadır. Ultrason terapi (TUS) bunlardan biridir. Fonofo rezis ise emilim ö zelliği olan ilaçların TUS eşliğinde lokal olarak bölgeye emdirilmesidir. Deneysel çalışmamızda 40 adet erkek, 1 yaşında, ortalama 3 kg ağırlığında, Yeni Zelanda tavşanı kullanıldı. Tavşanlar 4 gruba ayrıldı ve tüm tavşanların her iki arka bacağında deneysel Aşil tendo rupturu oluşturuldu ve hemen akabinde tenorafi ile onarıldı. Birinci ve üçüncü gruptaki tavşanların sağ bacaklarına operasyondan sonraki 10 gün boyunca ultrason terapi uygulandı. İkinci ve dördüncü gruptaki tavşanların sağ bacaklarına ise ope rasyondan sonraki 10 gün boyunca fonoforez uygulandı. Tüm çalışma gruplarında, sol bacaklar kontrol grubunu oluşturdu. Tavşanlar 30. gün sonunda ötenazi edilerek grup 1 ve 2’deki örnekler histopatolojik olarak, grup 3 ve 4’teki örnekler ise biyomekanik olarak incelendi. Biyomekanik inceleme için tendoların kopma noktaları N (Newton) cinsinden karşılaştırıldı. Çalışmanın sonucunda; ultrason terapinin fonoforezle karşılaştırıldığında tendo iyileşmesi için daha üstün bir metod olduğu kanısına varıldı., Tendon ruptures occur generally at distal portions of extremities and require relatively long recovery period. Traumatic ruptures of Achilles tendon need 6 -8 weeks of immobility period including pre and postoperative days. In order to avoid other orthopedical problems by this application and to speed up the reco very period, postoperative local administrations are done. Therapeutic Ultrasound (TUS) is one of these applications. Phonophoresis is the local absorbing procedure of some drugs by me ans of TUS which is applied to the affected area. Forty male New Zealand rabbits were used in the study which were one year old and mean 3 kg body -weight. The rabbits were divided into 4 groups and experimental Achilles tendon rupture was created in both legs of all rabbits and repaired immediately by tenorrhaphy. The right le gs of rabbits of groups 1 and 3 were treated postoperatively with TUS for 10 days. The right legs of rabbits in groups 2 and 4 were treated postoperatively with phonophoresis for 10 days. Left legs of all rabbits served as the control group. All rabbits we re euthanized at the end of the 30th day. Samples which were taken from groups 1 and 2 were examined histopathologically and those in groups 3 and 4 were examined biomechanically. In biomechanical investigations, the rupture points of the tendons in N (Newton) were compared. At the end of the study, it was concluded that TUS is a superior for tendon healing when compared to phonophoresis.

Laminated curved glasses as widely used elements in buildings urge to develop a mathematical model for their analysis and safer design. Large deflection theory is necessary in order to predict the true behavior of a laminated curved glass beam consisting of several glass layers bonded by soft interlayer PVB (PolyVinyl Butyral). In the present study, a mathematical model is developed for the analysis of a laminated circular arch or a laminated uniformly curved glass beam which is the special case of the laminated curved glass beams. Thus, three nonlinear, coupled partial differential equations governing the true behavior are derived in polar coordinates by applying variational and energy principles. Results of this model are compared with the results from the experiments and finite element model, and all of them are presented in figures to explain the true behavior. © 2013 Elsevier Ltd.

Amaç: Çalışmanın amacı ortodontik yüz maskesi kullanım süresi ve düzenini takip etmek amacıyla yüz maskesinin alın kısmına takılan yeni bir izleme sisteminin sunulması ve değerlendirilmesidir.Gereç ve Yöntem: Yeni izleme sistemi ana gövde, yuva kapağı ve sensör olmak üzere 3 ana parçadan oluşmaktadır. Ana gövde iki adet yan sabitleyici, bir adet orta sabitleyici, sensör takma yuvası ve sekiz vida deliğinden oluşmaktadır. Ana gövdedeki tüm parçaların yerleştirilmesini takiben sensör programlanmış ve yuvaya yerleştirilmiştir daha sonra kapak sabitlenmiştir. Sistem laboratuvar koşullarında test edilmiştir.Bulgular: Çalışma sonunda elde edilen verinin detaylı analizi göstermiştir ki izleme sistemi takma ve sökme süreçlerini doğru bir şekilde takip etmektedir. Yeni tipteki ortodontik yüz maskesi takma sürelerini ve düzenini izleyebilmektedir. Sonuç: Yüz maskesi tedavisi sagital yöndeki üst çene yetersizliğinin düzeltilmesinde elzemdir. Toplam kullanım süresi ve düzenli kullanım ortodontik ve ortopedik tedavinin başarısını etkileyen temel faktörlerdir. Objektif ve bilimsel olarak bu sürecin izlenmesi bu meşakkatli, uzun ve pahalı tedavide klinisyenlere büyük katkı sağlayacaktır. Bu çalışmanın sonucu göstermiştir ki yeni izleme sistemi yüz maskesi kullanımı için uygundur., Introduction: The aim of this study is to present and evaluate a new monitoring system attached to forehead part of face mask for tracking orthodontic face mask usage time and regularity. Methods: The new monitoring system consists of three main parts as main body, slot cover and sensor. The main body includes two lateral fixer, a median fixer, sensor insertion slot and eight screw holes. After completing the assembly procedure for the main part, the sensor is programmed and inserted to its slot and then the cover is screwed. The system was tested under laboratory condition.Results: Detailed analysis of the post study data showed that the system measured the attachment and detachment period correctly. The new type orthodontic face mask can monitor the wearing time and regularity.Conclusion: Face mask therapy is a crucial for correction of sagittal maxillary deficiency. Total wearing time and regularity is main factors to reach to a success level of this orthodontic and orthopedic treatment. Objective and scientific monitoring system proposed here may help the clinicians for difficult, long and expensive treatment. Conclusion of present study show that the system proposed is suitable for the further face mask usage.

As there is a gap in literature about out-of-plane vibrations of curved and variable cross-sectioned beams, the aim of this study is to analyze the free out-of-plane vibrations of curved beams which are symmetrically and nonsymmetrically tapered. Out-of-plane free vibration of curved uniform and tapered beams with additional mass is also investigated. Finite element method is used for all analyses. Curvature type is assumed to be circular. For the different boundary conditions, natural frequencies of both symmetrical and unsymmetrical tapered beams are given together with that of uniform tapered beam. Bending, torsional, and rotary inertia effects are considered with respect to no-shear effect. Variations of natural frequencies with additional mass and the mass location are examined. Results are given in tabular form. It is concluded that (i) for the uniform tapered beam there is a good agreement between the results of this study and that of literature and (ii) for the symmetrical curved tapered beam there is also a good agreement between the results of this study and that of a finite element model by using MSC.Marc. Results of out-of-plane free vibration of symmetrically tapered beams for specified boundary conditions are addressed. © 2017 Hamdi Alper Özyigit et al.

In this study, in order to determine the very early load transfer behavior in the bolted joint connection, experimental dynamic analysis of different laminated glass beams including two surface cracks is considered. For this purpose, both three different plastic interlayers (i.e., three types of polyvinyl butyral—PVB) and three different glass-lamina thicknesses are taken into account. Effects of the plastic interlayer, thickness of the glass-lamina, number of surface cracks and their locations on the vibration characteristics/structural performances are examined experimentally. Vibration tests are performed to present free vibration characteristics of the laminated glass beams under clamped-free boundary conditions. Experimental dynamic analysis consists of six parts: (I) vibration analysis with no-crack and no-hole with a bolted joint; (II) vibration analysis with a surface crack and no-hole with a bolted joint; (III) vibration analysis with two surface cracks and no-hole with a bolted joint; (IV) vibration analysis with no-crack and a hole with a bolted joint; (V) vibration analysis with a surface crack and a hole with a bolted joint; (VI) vibration analysis with two surface cracks and a hole with a bolted joint. For these experimental steps, an impact hammer with a force transducer is used to excite the uncracked or cracked composite beams through the selected points. After the excitation, the responses are obtained by an accelerometer. The vibration measurements are completed using a microprocessor-based data acquisition system and nCode GlyphWorks software. Results are given in tabular and graphical forms.

This work covers studies on systems with car tire regrind used as the toughening phase in epoxy resins. Different surface modification techniques were used to improve the compatibility at the interface between the rubber particles and the epoxy matrix. Silane coupling agents, plasma surface modification and acrylic acid/benzoylperoxide were used to enhance the surface properties of rubber particles. Rubber parts of ground used car tires, with or without surface treatment, were mixed with epoxy. This mixture was poured into molds to obtain mechanical test specimens according to ASTM standards. After curing, mechanical tests were performed and the fractured surfaces of the specimens were examined under Scanning Electron Microscopy, SEM. Throughout the studies, changes in mechanical properties were followed by an increase in the volume percentage of rubber particles and by the effect of different surface treatment processes applied on rubber. A decrease in tensile properties and impact resistance was observed in general as compared to unmodified epoxy. On the other hand, slight increases in fracture toughness values were observed in all surface treated cases.

The fabrication and characterization of bovine hydroxyapatite (BHA) and cerium oxide (CeO2) composites are presented. CeO2 (at varying concentrations 1, 5 and 10wt%) were added to calcinated BHA powder. The resulting mixtures were shaped into green cylindrical samples by powder pressing (350MPa) followed by sintering in air (1000-1300°C for 4h). Density, Vickers microhardness (HV), compression strength, scanning electron microscopy (SEM) and X-ray diffraction (XRD) studies were performed on the products. The sintering behavior, microstructural characteristics and mechanical properties were evaluated. Differences in the sintering temperature (for 1wt% CeO2 composites) between 1200 and 1300°C, show a 3.3% increase in the microhardness (564 and 582.75HV, respectively). Composites prepared at 1300°C demonstrate the greatest compression strength with comparable results for 5 and 10wt% CeO2 content (106 and 107MPa) which are significantly better than those for 1wt% and those that do not include any CeO2 (90 and below 60MPa, respectively). The results obtained suggest optimal parameters to be used in preparation of BHA and CeO2 composites, while also highlighting the potential of such materials in several biomedical engineering applications. © 2014 Elsevier Ltd., 2003K120810, This study was carried out mainly with the equipment furnished (between 2007–2008) to Marmara University with the support of the Turkish Republic Government Planning Organization in the framework of the project 2003K120810 “Manufacturing and Characterization of Electro-Conductive Bioceramics”.

Muscle groups affected on biting force are called temporal muscle as a major and masseter muscle as a minor. According to the human posture stability, forces of these muscles vary with the force directions. In this case, experimental investigation is strictly important such that biting force under different postural and eye- positional situations is changed. In this study, seven-male and seven-female within the age-range of 17-24 are considered corresponding to having with restorated molar tooth and without that type of tooth. With the help of specially designed biting fork, different posture- and eye-positions are investigated for experimental biting force analysis. Changes in eye-positions are not indicated significant difference for all postural positions. On one hand, it is obtained that biting force of no-filling tooth in men becomes maximum if facial muscles give full effort to biting. On the other hand, effect of facial muscles for women is not clearly noticed depending on the postural differences.

We investigated the possible effects of three pedicular screws on axial pull-out strength in pedicular revision surgery.Two study groups were formed from calf lumbar vertebrae. Initially, Alici pedicular screws with an outer diameter of 6.5 mm were applied (with or without tapping) to all the pedicles. All the pedicles were subjected to axial pull-out testing to induce pedicular insufficiency. Then, Alici pedicular screws with an outer diameter of 7 mm were applied to the left pedicles. The right pedicles in the two study groups were assigned to receive two different types of pedicular screws with an expandable (enlargeable) end, respectively. Axial pull-out testing was repeated in both groups and the results were compared with the initial pull-out strength values.In the first group, 65% and 64% of the initial pull-out strengths were obtained with 7-mm Alici pedicular screws and with expandable pedicular screws, for the left and right pedicles, respectively. The corresponding pull-out strengths in the other study group were 70% and 68.5% of the initial values, respectively. Tapping of the screw hole entrance resulted in a mean decrease of 13% in the pull-out strength compared to screw applications without tapping.Pedicular screw revisions using a 0.5 mm greater screw in diameter did not provide adequate screw-bone inter-face strength and pedicle filling. Similarly, expandable pedicular screws did not contribute to screw stability.

The aim of this study was to compare the in vitro caries inhibition of various resin-based materials. Class V cavities were prepared in twenty-five freshly extracted human premolar teeth which were then restored with glass-ionomer cement (Chemfill II), compomer (Compoglass F, Dyract AP) and composite resin (Tetric Ceram and Z 100). The teeth were submerged in an acid gel for 6 weeks. Each specimen was sectioned. These sections were left in water for 24 hours, and then examined using polarized light microscopy. The lesion consisted of two parts, the outer surface lesion and the cavity wall lesion. There was no significant difference in the body depth of the outer lesion and in the depth of the wall lesion among teeth restored with Compoglass F, Dyract AP and Chemfill II (P > 0.05). There was a significant difference between those restored with Z 100 and Tetric Ceram (P < 0.05). The length of the wall lesion for the teeth restored with Chemfill II was significantly smaller than that in the remaining groups (P < 0.05). The length of the wall lesion for teeth restored with Tetric Ceram and Z 100 was significantly higher than in the remaining groups (P < 0.05). These results suggest that composite materials and compomer provide less caries inhibition than glass-ionomer cements. (J. Oral Sci. 46, 45-50, 2004)

Hyaluronic acid (HA) is a glycosaminoglycan polymer that has been found to have some beneficial effects on the prevention of adhesions in primary tendon repairs. The need for slow elimination preparations of HA has been identified. We have combined HA and carboxymethylcellulose (CMC) in order to get a slow elimination preparation of HA and studied its possible effect on primary tendon healing. A gel form of NaHe (19 mg/ml; mw: 6.5 x 10(6)) was mixed with Na CMC (degree of substitution: 0.8) under sterile conditions. A jelly like mixture was thinned and HA membrane was achieved after drying in the refrigerator. The right legs of Leghorn chickens (n = 30) were prepared under IM ketamine anaesthesia by making partial cuts (75%) of flexor profundus tendons at zone II in the second, third and fourth toes, and repaired using a modified Kessler type suture (5/0 nylon). HA-membranes were applied around the repair sites in the third toes while 0.5 ml of hyaluronic acid and saline were poured on to the repair sites in the second and fourth toes, respectively. Skin incisions were closed and the legs were splinted for 15 days. Biomechanical and histological controls were made at the first, second and third postoperative months. No wound dehiscence or exposure of repaired tendons was observed on the operated toes. After collection of samples by amputation at MP levels, two-phalanx free biomechanical assessment was done. The calculated peaks of differential joint motion were very similar to the corresponding non-operated contralateral toes in the HA-membrane treated group. The toe tip displacement curves also resembled the non-operated ones in this group. HA membrane was detected as blue particles on specimens taken at the 30th day following surgery. There were few adhesions in this group microscopically at the third month. Adhesions were similar in the HA treated group while dense adhesions were seen in the saline treated group. These findings suggest that HA membrane acting as a physicochemical barrier can prevent restrictive adhesions in primary tendon repairs.

The influence of bond-coating on the mechanical properties of plasma-spray coatings of hydroxyatite on Ti was investigated. Plasma-spray powder was produced from human teeth enamel and dentine. Before processing the main apatite coating, a very thin layer of Al2O3/TiO2 was applied on super clean and roughened, by Al2O3 blasting, Ti surface as bond-coating. The experimental results showed that bond-coating caused significant increase of the mechanical properties of the coating layer: In the case of the enamel powder from 6.66 MPa of the simple coating to 9.71 MPa for the bond-coating and in the case of the dentine powder from 6.27 MPa to 7.84 MPa, respectively. Both tooth derived powders feature high thermal stability likely due to their relatively high content of fluorine. Therefore, F-rich apatites, such those investigated in this study, emerge themselves as superior candidate materials for calcium phosphate coatings of producing medical devices. The methods of apatite powder production and shaping optimization of powder particles are both key factors of a successful coating. The methods used in this study can be adopted as handy, inexpensive and reliable ways to produce high quality of powders for plasma spray purposes. © 2006 Springer Science + Business Media, LLC., Centro de Investigação em Materiais Cerâmicos e Compósitos Fuel Cell Technologies Program, Acknowledgements The authors gratefully acknowledge the assistance of Yasar C¸ elik and Turgut Halamoglu from Senkron Ceramic Coating Inc. for the plasma-coating process, Prof. Dr. Hadi Ozbal from the Chemistry Department of Bogazici University for powder-preparation, and Prof. Dr. Nuri Akkas for the tensile strength tests. The financial support of the Portuguese FCT and CICECO are also gratefully acknowledged.