The goal study is benchmarking flexural strength FS of compressive strength CS, compression diametrical DTS (diametrically tensile strenght) and Vickers hardness for two nanocomposites experimental AD1 and AD3 achieved within the Research Institute in Chemistry Raluca Ripan Cluj Napoca and for the commercial product of the Kerr Premise company �. Electron microscopy aspects pre- and post-fracturing are also shown to highlight the structure of materials and spread

The use of dental radiographies is nowadays indispensible for the clinician, and the evolution of x-rays provide quality images of the anatomic structures. The indications for a radiographic exam must be based on a clinical examination of the patient. Although the most used radiographies in dentistry are the retroalveolar and the panoramic one, it is considered that the indication for a CBCT scanning should be professional justified and evaluated as a balance between the benefits and the risk of exposure at radiation. The CBCT scans provide good quality images of the anatomic structures, with an accurate delimitation of the pathologic lesions, fact that allows the practitioner to proper evaluate the surrounding structures. CBCT technique uses an x-ray beam shaped like a cone that records 3D images in a single gantry rotation (360 degrees) within 6-20 seconds, with a radiation dose that depends on several factors. The comparison of the radiation dose of the CBCT (11-674 mSv) and the panoramic radiography (2.7�24.3 mSv) demonstrates that the CBCT requires a higher dose of radiation, but the high image quality is competing with the ones obtained with MSCT (280�1,410 mSv). The panoramic radiography uses an x-ray beam that is angled at aproximately 8 degrees, providing the practitioner a 2D radiographic image of the anatomic structures. The disadvantages of the panoramic radiography are the overlapping of the anatomic structures, the distortion and the blurry image. The study is based on the measurements of cystic lesions of the mandibular and maxillary bone that were present on radiographies and CBCT scans of 25 patients. The result of the measurements was that significative differences were found between the panoramic image of the cyst and the reconstructive image that the CBCT.

The purpose of this study was: Structural characterization of two commercial nanocomposite materials (Premise ™/Kerr Corp and Tetric EvoCeram�/ Ivoclar-Vivadent); Evaluation of the marginal adaptation and adhesive interface achieved with two commercial adhesive systems (Optibond SoloPlus ™/Kerr Corp and G-Bond ™/GC). Investigation was done using electronic scanning microscopy (SEM).

The glass ionomer cements present very good bio compatibility especially due to the presence of Fluor in their composition. The reactivity from the dental pulp to the ionomer cements is also favorable, even in the case of the profound cavities. The metallic ionomer cements are obturation materials that tend to replace the amalgams and were created by adding of metallic alloys to the glass powder for the purpose of improving the mechanic properties. The resistance to abrasion of the glass ionomer cements reinforced with Ag is increased compared to the ionomer cements, being close to that of the composite resins with micro filling, but inferior to the amalgams or composites for the posterior area. All these properties of the metallic glass ionomers recommend their utilization in accomplishing the definitive obturations of the permanent teeth from the lateral area, where the physiognomic aspect is not on the first place and where it is necessary a material with fast grip. The physical-chemical qualities and the bio compatibility of the glass ionomers reinforced with particles of silver was our premise in their utilization for the obturation of the molars of six years in children.

Marginal adaptation at composite enamel interface was assessed through direct clinical method, three-dimensional scanning and optical microscopy respectively for three composite materials with Nano filler: Tetric EvoCeram� (Ivoclar Vivadent-), Premise™ (Kerr Corp.) and experimental material C20 (�Raluca Ripan� Chemistry Research Institute, Cluj-Napoca). Clinical evaluation of marginal adaptation highlights at 6 months and at 12 months a rate of 25-40% marginal defects, regardless the Nano composite material used. Characterisation of interface between Nano-composite material and dental tissue requires a complex multifactorial assessment.