Polyetheretherketone (PEEK) material is a polycyclic, aromatic, thermoplastic polymer that is semi-crystalline and has a linear structure. PEEK has good mechanical and electrical properties such as resistance to high temperature and resistance to hydrolysis. In addition, because of the property of high biocompatibility, use of PEEK has increased in orthopaedic and trauma cases. The most characteristic property of PEEK material is that it has a low elasticity modulus, close to that of bone. It has been suggested that stress-based problems could be reduced with this material due to the low elasticity modulus. In the light of this information, PEEK material could be considered as an alternative to conventional materials in the field of dentistry.

In the field of restorative dentistry, the use of composites has become widespread with increasing aesthetic demand. Nowadays the composites are divided into various classes depending on the type and size of the filler particles. Apart from this, many new composites have been produced in order to protect the healthy tooth structure, to reduce microleakage and secondary caries formation, to reduce marginal pigmentation and postoperative sensitivity together with developments in technology. The aim of this review is to improve the clinical performance and to evaluate new composite resins that will provide more selection criteria for dentists.

Together with developments in digital imaging systems, there has been increasing use of micro-computed tomography (μCT) in many areas, primarily in dentistry. As this method allows 3-dimensional images to be taken providing safe and high quality results, without damaging the samples being examined, it is often preferred. Consequently, it has become possible to record rapid progression in endodontic studies in particular and to research and easily compare several techniques. Furthermore, this method can be used in tissue engineering, forming data for FEM analysis, the growth and development of craniofacial bones, imaging bone structure, and in the evaluation of implants and surrounding bone in root tip surgery, to determine mineral concentration in the teeth and to measure the thickness of enamel. The aim of this review was to focus on the areas of use of μCT in dentistry and state the advantages. Key Words: Micro-computed tomography, X-ray micro-CT, dental application, three-dimensional imaging   How to cite this article: Erpaçal B, Adıgüzel Ö, Cangül S. The use of micro-computed tomography in dental applications. Int Dent Res 2019;9(2):78-91.   Linguistic Revision: The English in this manuscript has been checked by at least two professional editors, both native speakers of English.

BackgroundThe aim of this study was to measure the distance between the maxillary premolar and molar teeth apices to the buccal cortical bone and evaluate differences in gender and age group, using cone beam computed tomography (CBCT).Material/MethodsThis retrospective study comprised of 451 premolar and molar teeth of one hundred and thirteen patients who were admitted to Dicle University, Faculty of Dentistry, Department of Dentomaxillofacial Radiology for different reasons. Data were analyzed using Student’s t-tests and Tukey HSD tests.ResultsThere was significant difference in buccal bone thickness by gender (p<0.05). The thinnest point of the maxillary buccal bone was measured in women as 2.11 mm and in men as 2.02 mm in the first premolar teeth. The thickest point of maxillary buccal bone was measured in women as 9.87 mm and in men 10.71 mm palatinal root of the first molar. A comparison of buccal bone thickness between age showed a statistically significant difference at the distobuccal and palatinal roots of the first molar, at the mesiobuccal root of the second molar (p<0.05).ConclusionsThe measurements of maxillar buccal bone thickness using CBCT for various dental procedures especially in endodontic surgery, orthodontic mini implant treatment, dental implant procedures, and healing after tooth extraction that are important knowledge.

Aim: Metal-supported ceramics as crown material and glass fibre posts as dental post materials are in frequent current use. In recent years, it has been claimed that stress-based biomechanical problems in dentistry can be resolved with the benefit of the low elasticity modulus of polyetheretherketone (PEEK) material. The aim of this study was to use finite element analysis (FEA) to compare the stresses formed by forces applied after the use of PEEK material as dental post and crown material as an alternative to glassfibre posts and metal-supported ceramic crowns. Material and Method: The stress analysis metthod used in this study was FEA. First, micro-computed tomography (micro-CT) images were obtained of a maxillary central incisor tooth and the data of the post materials scanned with a 3-dimensional (3D) laser scanner were uploaded to a computer program. 3D models were obtained with designs made in the computer program of all the materials. The modelling of a maxillary central tooth was completed using 2 different post materials (glassfibre and PEEK) and 2 different crown materials (metal ceramic and PEEK) and 4 groups were formed for analysis. By applying force of 100N at 135˚ from the absolute central point of the palatinal surface of the tooth, the stress values and distribution occurring in the 3D peiodontal models were compared.   Results: The use of PEEK post reduced the stresses occurring on the periodontal ligament (PDL) and the cortical bone, and caused no significant change in the stresses on the crown. The use of PEEK crown reduced the stresses occurring on the crown and increased the stresses occurring on the PDL and cortical bone. Conclusion: With further in vitro and clinical studies of PEEK material, it can be considered that within a short time PEEK post and PEEK crown could be in routine use in dentistry.

Imaging methods are of great importance for diagnosis and treatment in dentistry. With technological advances, great progress has been made in these methods. Over time, 3-dimensional (3-D) imaging has replaced 2-dimensional, thereby providing examination of objects in all directions. Of these methods, which play an important role in the clinical evaluation of patients, cone-beam computed tomography (CBCT) is the newest and most advanced imaging method. This method will revolutionize dental in comparison with conventional CT, it has several advantages, including a shorter scanning time, low radiation dose, low cost and the acquisition of high-resolution images. With 3-D imaging technology, this method has introduced the possibility of applying several procedures from diagnosis in the maxillofacial region to operative and surgical procedures. Although very clear results are not obtained from the imaging of soft tissues, the most important advantage of this technology is the capability of imaging hard and soft tissues together.   How to cite this article: Cangul S, Adiguzel O. Cone-Beam Three-Dimensional Dental Volumetric Tomography in Dental Practice. Int Dent Res 2017;7:62-70.  Linguistic Revision: The English in this manuscript has been checked by at least two professional editors, both native speakers of English.

The aim of the present study was to investigate and compare the quantity of residual monomers leached from the bulk-fill composites with different compositions polymerized at varying layer thickness. Three bulk-fill (X-tra-fil, Beautifil Bulk Restorative, Fill-Up) and a nanohybrid composite (Filtek Z550) were used for the study. The composite resin samples were prepared with a stainless steel mold. For each composite, two groups were constructed. The samples in the first group were prepared using the 2 + 2 mm layering technique. In the second group, the composite samples were applied as a 4 mm-thick one layer and polymerized. Then, each composite samples were kept in a 75% ethanol solution and residual monomers released from composite resins were analyzed with an HPLC device after 24hour and 1 month. The data were analyzed using Kruskal-Wallis and Mann-Whitney U tests. Except the Fill-Up, all of residual monomer elution from the bulk-fill composites was significantly affected by the layer thickness (p < 0.05). The greatest monomer release was detected at 1 month after polymerization as a single 4 mm layer for Beautifil Bulk Restorative. Fill-Up composite showed similar residual monomer release in polymerization at different layer thicknesses compared to other composite resins. In the 2 + 2 mm layering technique, the least monomer elution was detected in the Filtek Z550 composite group. While Bis-GMA was the most released monomer in X-tra fil composite, UDMA was the most released monomer in all other composite resins. During polymerization of the bulk-fill composite, the layer thickness of the composite applied may affect the amount of residual monomers released from the composite resins. Conventional composites may release less monomer than bulk-fill composites when used with layering.

No abstract