Background: The purpose of the study was to analyze the efficacy of platelet-rich fibrin (PRF) as a single augmentation material for complicated cases of maxillary sinus floor elevation, resulting from membrane perforation or previous infections. Methods: Implant insertion in the posterior region of the maxilla was simultaneously performed with maxillary sinus floor augmentation. Schneiderian membrane elevation can be accompanied by extremely serious sinus membrane perforation, due to accidental tearing or intended incision for mucocele removal. PRFs were placed in the sinus cavity both for membrane sealing and sinus floor grafting. Radiological, histological and micro-CT analyses were performed. Implant survival was assessed every 6 months for 1 to 4 years, with a mean follow up of 1.8 years, after prosthetic loading. Radiological examinations were performed on CBCT at 9 and 12 and 36 months postoperatively and revealed improved degrees of radiopacity. Results: 19 implants were simultaneously placed in the course of nine maxillary sinus floor augmentation surgeries, with successful outcomes in terms of bone grafting and implant integration. New bone formation was evidenced 12 months postoperatively on radiological examination, micro-CT analysis, and histological analysis of a harvested bone segment from the augmented maxillary sinus. The mean gain in bone height of the sinus floor augmentation was 6.43 mm, with a maximum of 9 mm. The mean amount of vital bone obtained from histologic assessment was 52.30%, while bone volume/tissue volume ratio in micro-CT 3D had a mean of 50.32%. Conclusions: PRF may be considered as an alternative treatment for a single surgery of sinus augmentation with simultaneous implant placement, even in complicated cases with significant sinus membrane tearing.

Utilization of computer-aided design/computer-aided manufacturing (CAD/CAM) rapidly increases in dental medicine. Making of computer-engineered complete denture is based on scanning of patient data, designing of prosthesis and milling or rapid prototyping. This is digital denture, term that includes innovative devices, software programmes and corresponding materials. Industrially polymerized cross-linked polymethyl methacrylate (PMMA) is the material used for fabrication of digital denture. The aim of this study is to analyze the different cross-linked PMMA used for fabrication of CAD/CAM complete denture.

The aim of this study was to evaluate the interim veneer restoration, achieved from two types of dimethacrylate based composite resins (Telio CS C and B and Luxatemp Star), by direct technique. Both composite resins performed well according to evaluation criteria: anatomic configuration, marginal adaptation, discoloration, surface texture, postoperative pain and periodontal aspect. Loosening of interim restorations appeared in 25% of cases. Besides advantages, there are some disadvantages associated with direct way of achieving temporary veneers.

The aim of the finite element analysis (FEA) is to determine the stress and deformation state of all elements of four mechanical assemblies under certain loading and fastening conditions of the structure. The structure of the finite element analysis consists of GIC and 4 geometric variables (no bone loss, 1 surface radial loss, 2 surfaces and circumferential loss). Geometric reconstruction of simulated elements is done based on the X-ray scan images. The DICOM image collection is imported into Mimics 10.01, where two color layers are applied, which are then transformed into volumes. Surface integrity was accomplished using Geomagic Studio 2013 software. Subsequent to the reconstruction, classical geometric modeling was carried out using the SolidWorks 2013 CAD environment. Four geometric models were made and the assembly described above was inserted. Finite element analysis was performed with the Ansys 13 software. For resin composite restorations, in the case of circumferentilly bone loss, the restoration pressure drops due to increased tooth elastic deformation possibilities. In case of bone loss on one face and two sides of the tooth, there is a strong pressure on the cementum-bone interface, due to the bending effect that occurs. Pressures in dental root restorations are higher in the case of reconstruction using resin composite.

The aim of the present study is to compare the marginal adaptation of direct, semi-direct and indirect restorations made with nanofill and microhybrid composite materials and ormocers materials bonded with SE adhesives at the dentin and cementum. 120 standardized class II cavities were prepared (40 for each techniques- RD, RSD, RI) with the gingival margin over and below to the cementum-enamel junction. The teeth (n= 20) were restored using one of three adhesive systems (OptiBond XTR, G-Premio Bond bottle refill, Futurabond U) with incrementally placed composite restorations and ormocers. After applying the various restorations, the teeth were prepared for SEM analysis to check the marginal adaptation by the presence of continuous margins or gaps. Comparative analysis of treatment methods and materials used was performed by statistical analysis of Chi-square test data, the statistical significance was p [0.05 and Fisher�s Exact Test for validation of results. It was found that among the three materials used for RD, RSD, RI both at the dentin and the cementum, there are no significant differences (RD d = 0.661, RSD/d = 0.755, RSD/c = 0.942; RI/d = 0.739; RI/c = 0.985). Comparison between the presence of continuous margins/gaps subgingivally and supragingivally at the three types of restorations shows that there are significant differences between the marginal adaptation at the cementum and dentin to all the restoration techniques used (p [0.05). Direct and indirect restorations with nanocomposites and ormocers bonded with 1-step SE adhesive are the best solutions for restoring the posterior teeth.