1,721,174 research outputs found
Reproducibility of measurements in tablet-assisted, PC-aided, and manual cephalometric analysis
No full textObjective: To assess the reproducibility of cephalometric measurements performed with software for a tablet, with a program for personal computers (PCs), and manually. Materials and Methods: The pretreatment lateral cephalograms of 20 patients that were acquired using the same digital cephalometer were collected. Tracings were performed with NemoCeph for Windows (Nemotec), with SmileCeph for iPad (Glace Software), and by hand. Landmark identification was carried out with a mouse-driven cursor using NemoCeph and with a stylus pen on the iPad screen using SmileCeph. Hand tracings were performed on printouts of the cephalograms, using a 0.3-mm 2H pencil and a protractor. Cephalometric landmarks and linear and angular measurements were recorded. All the tracings were done by the same investigator. To evaluate reproducibility, for each cephalometric measurement the agreement between the value derived from NemoCeph, that given by SmileCeph and that measured manually was assessed with the intraclass correlation coefficient (ICC). Agreement was rated as low for an ICC ≤0.75, and an ICC > 0.75 was considered indicative of good agreement. Also, differences in measurements between each software and manual tracing were statistically evaluated (P 0.8, indicative of a high agreement among the tracing methods. Relatively lower ICCs occurred for linear measurements related to the occlusal plane and to N perpendicular to the Frankfurt plane. Differences in measurements between both software programs and hand tracing were not statistically significant for any of the cephalometric parameters. Conclusion: Tablet-assisted, PC-aided, and manual cephalometric tracings showed good agreement. ©2014 by The EH Angle Education and Research Foundation, Inc
Sealing ability of packable resin composites in class II restorations
No full textPurpose: To evaluate in Class II restorations the marginal adaptation often packable composite resins in combination with the proprietary adhesive system. Materials and Methods: Standard Class II cavities were prepared in 100 extracted molars. The sample was randomly divided into ten groups. In each group, one specific packable composite was tested in association with its own adhesive: Groups: 1) Scotchbond1/FiltekP60; 2) Etch&Prime3.0/Definit; 3) Prime & Bond 2.1/SureFil; 4) Excite/Tetric Condensable; 5) Gluma/Solitaire; 6) Kerr Bonding/Prodigy Condensable; 7) One-step/Pyramid; 8) Tenure/Virtuoso; 9) Syntac/Cavex Packable; 10) Excite/Tetric flow/Tetric Ceram. The restored teeth were sectioned at three levels in the mesiodistal direction and processed for the microleakage test. On each section, the degree of dye penetration along the margins of the restoration was assessed, and the differences in the leakage given by the ten materials at either the occlusal or the cervical margin were evaluated for statistical significance. A statistical analysis was also conducted to assess the significance of the differences between the scores recorded at the occlusal margin and those measured at the cervical margin of the restoration. Results: In general, the scores recorded at the cervical margin were significantly higher than those measured at the occlusal margin (p < 0.05). When all of the groups were compared for microleakage at the occlusal margin, the only significant difference revealed by the statistical analysis was that the specimens treated with Etch&Prime 3.0 and Definit (group 2) exhibited a marginal adaptation significantly worse than that seen in groups 1, 3, 4, 6, 8, 10. Conclusion: The application of a thin layer of a flowable composite at the cervical margin as a liner underneath the packable composite enhanced the marginal adaptation of the restoration. The use of a self-etching primer to condition the dental substrate resulted at the occlusal margin in greater microleakage than when phosphoric acid was applied
Bonding to worn or fractured incisal edges: Shear bond strength of new adhesive systems
No full textObjectives: Resin composites can be proposed for the restoration of incisai edges. If a progressive wear or an old fracture is responsible for the loss of the incisai edge, the bonding substrate is likely to be sclerotic dentin, surrounded by enamel. The purpose of the study was to measure under laboratory conditions, the shear bond strength of three adhesive systems to the enamel and dentin exposed on the edge of incisors as a result of a long-time wear or an old fracture. Method and materials: Thirty extracted human incisors were selected. The teeth had to exhibit some exposed dentin on their edges, a result of old fractures or wear. The 30 specimens were randomly divided into three groups. In each group, a different adhesive system was tested for the ability to efficiently bond a resin composite restoration to the dental substrate. A three-step system (Scotchbond Multipurpose Plus), a one-bottle adhesive (Scotchbond 1), and a self-etching adhesive (Prompt-L-Pop) were compared. The shear bond strength of the restored samples was measured under a loading machine. The pattern of failure that each sample underwent as a result of loading was assessed under a stereomicroscope. Results: The highest values of bond strength were yielded by Scotchbond Multipurpose Plus (28.14 MPa), followed by Scotchbond 1 (16.15 MPa), and Prompt-L-Pop (9.26 MPa). These differences were statistically significant (P < .05). The most frequent pattern of failure was the combined adhesive-cohesive in resin fracture. Conclusion: Adhesive systems involving phosphoric acid etching of the substrate were more dependable than a self-etch adhesive when bonding a resin composite restoration to worn or fractured incisal edges
Current perspectives on post systems: a literature review
No full textThis literature review summarizes the most recent and reliable evidence on post systems. A search was limited to review articles published over the last 10 years in dental journals with an impact factor. Papers cited in the initially retrieved review articles were also included if significant. Preservation of tooth tissue, presence of a ferrule effect, and adhesion are regarded as the most effective conditions for long-term success of post-endodontic restorations. Adhesively luted fibre-reinforced composite post restorations have demonstrated satisfactory survival rates over relatively long follow-up periods. The clinical effectiveness of such restorations has been mainly ascribed to the more biomimetic behaviour of fibre-reinforced composite posts that reduces the risk of vertical root fractures. The most common type of failure when using fibre posts is post debonding and it is generally agreed that achieving stable adhesion to intraradicular dentine is more challenging than to coronal dentine. Several factors related to endodontic treatment, root canal shape, post space preparation, post translucency, adhesive cement handling and curing may have an influence on the outcome of the luting procedure. The most reliable results in fibre post cementation are obtained by etch-and-rinse adhesives in combination with dual-cure resin cements. The use of self-adhesive resin cements has also been proposed. Simplification is an obvious advantage of these new materials. However, the durability of their bond still needs to be verified with long-term clinical studies. Several techniques for pre-treating the fibre-reinforced composite post surface have been tested with the aim of improving the bond strength at the post-core and post-cement interfaces. Silicoating followed by silanization currently appears to be the most effective and convenient method for this purpose. In conclusion, the available evidence validates the use of fibre posts as an alternative to metal posts and preferably to other tooth-coloured posts, such as zirconia dowels, in the restoration of endodontically treated teeth. Longer term clinical trials are expected to further strengthen this evidence
Long term effect on tooth vitality of regenerative therapy in deep periodontal bony defects: A retrospective study
No full textLong-term effect on tooth vitality of regenerative therapy in deep periodontal bony defects: a retrospective study
No full textOver the last few decades, many authors have investigated the effect of periodontal disease and treatment on pulpal status with controversial results. This study was conducted to verify whether periodontal disease in a deep intrabony defect and complex therapy, including aggressive root planing such as in periodontal regeneration, have an influence on tooth vitality. One hundred thirty-seven patients who fulfilled the requirements were included. The collected data did not support the need for "preventive" root canal treatment in severely compromised teeth that are planned to undergo periodontal regenerative surgery. © 2013 by Quintessence Publishing Co Inc
Long-term effect on tooth vitality of regenerative therapy in deep periodontal bony defects: a retrospective study.
No full textOver the last few decades, many authors have investigated the effect of periodontal disease and treatment on pulpal status with controversial results. This study was conducted to verify whether periodontal disease in a deep intrabony defect and complex therapy, including aggressive root planing such as in periodontal regeneration, have an influence on tooth vitality. One hundred thirty-seven patients who fulfilled the requirements were included. The collected data did not support the need for "preventive" root canal treatment in severely compromised teeth that are planned to undergo periodontal regenerative surgery
Micromorphology of the fiber post-resin core unit: a scanning electron microscopy evaluation
No full textThe structural characteristics of post-and-core units made with a fiber post and different types of composite resins used as build-up materials in dentistry were investigated. Scanning electron microscopy was used for the analysis. The presence of voids/bubbles within the resin abutment were also detected. A higher homogeneity of the abutment and a better post-core integration were achieved when hybrid composites were used
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