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.

No abstract

Socio-economic indicators and parents' level of education were not statistically significantly associated with the occurrence of traumatic dental injuries. Factors associated with increased risk of dental injuries in permanent teeth were age, gender, having an incisal overjet greater than 5mm and anterior open bite.

Dental cements are widely used in dentistry. Base material, temporary filling material and luting agents can all have different clinical applications. Different types of cement have also been developed for various orthodontic and endodontic treatments.In literature it is still argued that there is not ideal cement answering all purposes yet, so different materials are required for the comprehensive patient treatments and it is not always that easy to make the best choice.The aim of this article is to provide a clinically relevant discussion of contemporary permanent luting agents, in order to enhance the dentist's ability to make proper cementation choices and application.

BackgroundThe mouth is exposed to thermal irritation from hot and cold food and drinks.Thermal changes in the oral cavity produce expansions and contractions in tooth structures and restorative materials. The aim of this study was to investigate the effect of temperature and stress distribution on 2 different post systems using the 3-dimensional (3D) finite element method.Material/MethodsThe 3D finite element model shows a labio-lingual cross-sectional view of the endodontically treated upper right central incisor and supporting periodontal ligament with bone structures. Stainless steel and glass fiber post systems with different physical and thermal properties were modelled in the tooth restored with composite core and ceramic crown. We placed 100 N static vertical occlusal loading onto the center of the incisal surface of the tooth.Thermal loads of 0°C and 65°C were applied on the model for 5 s. Temperature and thermal stresses were determined on the labio-lingual section of the model at 6 different points.ResultsThe distribution of stress, including thermal stress values, was calculated using 3D finite element analysis.The stainless steel post system produced more temperature and thermal stresses on the restorative materials, tooth structures, and posts than did the glass fiber reinforced composite posts.ConclusionsThermal changes generated stresses in the restorative materials, tooth, and supporting structures.

Nowadays, demand for esthetic restorations has risen considerably; thus, nonmetal esthetic posts made of either highstrength ceramics or reinforced resins, such as fiber-reinforced resin posts, have become more and more popular. Important characteristics of fiber-reinforced posts involve a modulus of elasticity similar to dentin and their ability to be cemented by an adhesive technique. A total of 36 maxillary incisors were divided into four groups. In this study, four adhesively luted fiber-reinforced (glass fiber, quartz glass fiber, zirconia glass fiber and woven polyethylene fiber ribbon) post systems were used. Post spaces were prepared by employing drills according to the protocol established for each group, and each post was adhesively luted with one of three adhesive systems. Three segments per root apical to the cementoenamel junction (CEJ) were obtained by sectioning the root under distilled water with a carbon spare saw. The samples (total of 108 sections) were 2.0±0.1 mm in thickness and they were stored individually in black film canisters with sterile distilled water. In order to determine the bond strength, the bonding area of each specimen was measured, and specimens were attached to a device to test microtensile strength at a speed of 1 mm/min. The analyses revealed no statistically significant differences between the adhesive systems and fiber-reinforced posts. (P> 0.05). However, the coronal portion of the root dentin had the highest bond strength. Adhesive systems used along with fiber-reinforced resin posts demonstrated reliable bonding.

No abstract

BackgroundEndodontically treated teeth with excessive loss of tooth structure are frequently restored using fiber posts. In this in vitro study, the apical leakage of self- and dual-activated curing modes for dual-curing resins cementing a translucent fiber post was evaluated using computerized fluid filtration meter and dye extraction method.Material/MethodsOne hundred and four extracted human maxillary incisors with single root and canal were used. Experimental samples embedded in a closed system were divided into 4 groups (n=20) according to 2 dual-curing luting systems, with 2 different curing modes (either with self- or light-activation): (1) Panavia F 2.0 with self-cure, (2) Panavia F 2.0 with light-activation, (3) Clearfill SA with self-cure, and (4) Clearfill SA with light activation. Twenty-four teeth served as negative and positive controls. Translucent fiber posts were luted in the roots except in the control groups.ResultsStatistical analysis indicated no significant difference in leakage among groups (p>0.05) with 4.12×10−4 (Panavia self-cure), 4.55×10−4 (Clearfill SA self-cure), 5.17×10−4 (Panavia dual-cure), and 5.59×10−4 (Clearfill SA dual-cure) in fluid-filtration method. Absorbance values for dye-extraction method were 266 nanometer (nm) (Panavia self-cure), 268 nm (Clearfill SA self-cure), 270 nm (Panavia dual-cure), and 271 nm (Clearfill SA dual-cure), in which difference among the groups were not statistically significant (p>0.05). When comparing the leakage, assessment methods results showed no statistically significant difference between the tested evaluation techniques (p>0.05).ConclusionsLight- and self-activation curing modes of Panavia F 2.0 and Clearfill SA perform similar to each other in a closed system.