Color match is one of the most important characteristics of aesthetic restorative materials. Maintenance of color throughout the functional lifetime of restorations is important for the durability of treatment. This characteristic is not constant among dental materials. The purpose of this research was to assess the color stability of five aesthetic restorative materials when immersed in a coffee solution. Seventy-one 17 mm x 1 mm specimens, divided into five groups, were made using one direct composite resin (Tetric Ceram, Ivoclar/Vivadent - G1), three indirect composite resins (Targis, Ivoclar/Vivadent - G2; Resilab Master, Wilcos - G3; belleGlass HP, Kerr - G4) and one porcelain (IPS Empress 2, Ivoclar/Vivadent - G5). The specimens were immersed in a coffee staining media for 15 days and stored under a controlled temperature of 37 degrees C +/- 1 degrees C in the dark. The evaluations were made after 1, 7 and 15 days by means of reflectance spectrophotometry. The data was submitted to two-way ANOVA (p < 0.005) and post hoc tests. Statistical difference was observed between G1 / G3 and the other groups; G2 / G4 and the other groups; and G5 and all the other groups. It was concluded that G1 and G3 showed significantly higher discoloration than the other groups. G2 and G4 showed intermediary pigmentation, while G5 showed the smallest changes.
The subjectivity of the visual method might not be a clinical concern in daily practice. The human eye can detect small differences in color and visualize the tooth with all its complex geometry, multilayered tissues, and secondary color parameters. Therefore, any color-matching task will be judged by the patient and/or other observers with consideration to this complexity. In other words, visual assessment is paramount to the success/failure of esthetic restorative procedures. The efficiency of the visual color method may be improved by color education through the development of professional color discrimination ability. This would make the students responsible for color selection, reproduction, and evaluation and lead to increased capability over a layperson observer receiving the restorative treatment. (J Esthet Restor Dent 29:E24-E32, 2017).
Objective: The CAD/CAM process in Dentistry describes an indirect restoration designed by a computer (Computer Aided Design) and milled by a computer assisted machine (Computer Aided Machined). It can be divided into three different steps: data acquisition, indirect restoration design and construction of the prosthesis itself. This paper relates the state of art of the CAD/CAM systems in dentistry and some of the concerns and special cares that can interphere to optimize their results. Yet, it stablish some considerations about the role of CAD/CAM systems in the present and near future of the dental practice.Methods: The Scientific Electronic Library Online (SCIELO) and biomedical journal literature of the National Library of Medicine (MEDLINE/PubMed) electronic databases were used to search the literature from 2004 to 2013.Conclusion: There are advantages to using CAD/CAM in Dentistry: the new materials are esthetically pleasing and durable; there is increased efficiency in laboratory processing; quick fabrication of the restoration; and quality control of restorations such as fit, mechanical durability and predictability. These advantages will ultimately benefit our patients.
Objectives: To evaluate the effects of etch-and-rinse and self-etching adhesive systems on Vickers hardness (VHN) uniformity of dual-cured resin cements after fiber post cementation.Methods: Fifty glass fiber posts were cemented into bovine roots using the following cementing systems: Prime&Bond 2.1 Dual Cure and Enforce with light-activation (PBDC-LCEN); Prime&Bond 2.1 and Enforce with light-activation (PB-CLEN); Prime&Bond 2.1 Dual Cure and Enforce without light exposure (PBDC-SCEN); ED Primer and Panavia 21 (ED-SCPN); and Clearfil SE Bond and Panavia 21 (CF-SCPN). The roots were stored in distilled water for 72 h and transversely sectioned into thirds (coronal, medium, and apical). The VHN values of the resin cement layers were measured close to the post and to the dentin wall on the transversely sectioned flat surfaces. The results were analyzed by three-way repeated measures analysis of variance (ANOVA) and Tukey’s post-hoc test (pre-set alpha of 5%).Results: Most resin cements presented higher VHN values near the post than near the dentin
wall. The ED-SCPN group showed the highest VHN values regardless of the root third, while the selfcured
group PBDC-SCEN exhibited the lowest values. The resin cements from the light-activated
groups PBDC-LCEN and PB-LCEN showed lower VHN values at the apical third than at the coronal
third. The VHN values were not influenced by the root third in self-cured groups PBDC-SCEN, EDSCPN,
and ED-SCPN.Conclusions: Depending on the product, bonding agents might promote changes in hardness uniformity of resin cements after post cementation. (Eur J Dent 2012;6:248-254)
Aim: To compare the accuracy (trueness and precision)of cost-accessible three-dimensional (3D) printed models.Methods: A maxillary typodont (MM) was scanned andprinted 10 times in polylactic acid, resulting in 10 digitalmodels (DMs). Polyvinylsiloxane impressions were made toobtain 10 conventional stone models (SMs). All models werescanned and imported to CloudCompare software. The totalarea and three locations of interest were evaluated (zenith toincisal [Z-I], canine to canine [C-C], and first molar to canine[1M-C] distances). Total area evaluations were performed byaligning the MM and experimental models using the best-fitalgorithm and were compared using the Haussdorf distance.The distances between points of interest were measured usingthe point-picking tool at the same 3D coordinates. The meanvolumetric deviations were considered for trueness analysis.Precision was set as the standard deviation. Statisticaldifferences were evaluated using the Student’s t-test. Results:Total area volumetric comparisons showed that DMs showedsuperior trueness and precision (-0.02 ± 0.03) compared tothe SMs (0.37 ± 0.29) (P < 0.001). No differences between themodels were observed for Z-I (P = .155); however, SMs showedfewer deviations for C-C (P = .035) and 1M-C (P = .001) thanDMs. Conclusions: The DMs presented superior trueness andprecision for total area compared to the SMs; however, the SMswere more accurate when points of interest were evaluated.
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