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Purpose: To evaluate the marginal quality of composite resin restorations placed in extracted molars either in bulk (4 mm) or three increments. Materials and Methods: Sixteen extracted mandibular molars were selected and two two-surface cavities were prepared in each tooth (proximal depth 4 mm, occlusal width 5 mm). On one side of the tooth, Tetric EvoCeram Bulk Fill (Ivoclar Vivadent) was applied in a single increment; on the other side, Tetric EvoCeram (Ivoclar Vivadent) was applied in three increments: a horizontal gingival, an oblique buccal, and an oblique lingual increment. Each layer was light cured for 10 s with a Bluephase G2 curing light (1200 mW/cm²). Two adhesive systems were employed according to the instructions for use: the single-component etch-and-rinse system ExciTE F (Ivoclar Vivadent) and the self-etching two-component system AdheSE (Ivoclar Vivadent). The adhesive was light cured for 10 s with a Bluephase G2 curing light (1200 mW/cm²). Eight fillings were placed for each test group and all restoration margins were confined to the enamel. After 10,000 cycles of thermocycling (5°C/55°C), the quality of the proximal margins was semiquantitatively directly evaluated with a stereomicroscope at low magnification and a dental explorer using the SQUACE (semi-quantitative evaluation of restorations) method. In addition, replicas were made for SEM analysis, which was carried out four weeks later at high magnification (200X) by measuring the percentage of regular proximal margins in relation to the entire margin. Results: After thermocycling, statistically significantly higher percentages of regular margins were detected for those fillings placed with the etch-and-rinse system ExciTE F than for those placed with the self-etching system AdheSE -- irrespective of the evaluation method (Mann-Whitney non-parametric test, p < 0.05). There was no statistically significant difference between the resin restorations placed in bulk and those placed in three increments (Mann-Whitney, p > 0.05). The semi-quantitative evaluation by means of a light microscope yielded statistically significantly higher values for regular margin than did the SEM evaluation for all 4 test groups (p < 0.05). Pearson's correlation coefficient for both evaluation groups was 0.87 (p < 0.0001). Conclusions: The marginal quality of medium-sized Class II restorations of composite resins placed in one increment was similar to that of restorations placed in several increments. The semiquantitative evaluation of the marginal quality with an explorer at low magnification is an effective and rapid method to predict the clinical performance of direct restorations. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the wear in vitro of a new ion-releasing powder/liquid polymer resin in relation to that of glass-ionomer derivatives and conventional composites. Methods: Flat specimens (eight per material) of the ionreleasing powder/liquid polymer resin Cention N, five resin-modified glass-ionomer cements [ChemFil Rock, Equia Fil (with and without coating), Fuji II, Photac Fil, Riva], six conventional glass-ionomer cements (Fuji IX, Fuji IX GP, Ionofil Molar, Ketac Fil Plus, Ketac Molar, Ketac Universal), and two popular conventional resin composites (CeramX, Filtek Z350 XT) were processed and luted to aluminum holders. After storage in water at 37°C for 24 hours, the specimens were polished to 2,500 grit and subjected to the Ivoclar wear method, which mainly simulates attrition wear using a commercially available chewing simulator. A standardized stylus made of pressable ceramic (IPS Empress) hits flat specimens 120,000 times with a 5 kg weight and a lateral movement of 0.7 mm under constant exchange of water at different temperatures (5°C/55°C). The vertical loss was measured on plaster replicas with a laser scanner and 3D software. The Ivoclar wear method moderately correlates with clinical wear. Results: The mean vertical wear of the resinmodified glass-ionomer cements was statistically significantly higher, between 616±44 pm (Ionofil Molar) and 946±101 pm (Fuji IX GP) than that of the ion-releasing polymer resin Cention N (327±63 pm) (ANOVA post-hoc Tukey B, P< 0.01), which was in the same statistical group of the conventional resin CeramX (323±31 pm). Filtek Z350 XT showed significantly lower wear (221±19 pm) (ANOVA post-hoc Tukey B, P< 0.05). The materials ChemFil Rock (39±13 pm), Photac Fil (41 ±9 pm), and Fuji II (42±8 pm) had the lowest antagonist wear, while Ketac Fil Universal (143±37 pm) and CeramX (135±13 pm) had the highest antagonist wear. Antagonist wear for Cention N was somewhere in between (90±21 pm). [ABSTRACT FROM AUTHOR]

In 2007, new clinical criteria were approved by the FDI World Dental Federation and simultaneously published in three dental journals. The criteria were categorized into three groups: esthetic parameters (four criteria), functional parameters (six criteria), and biological parameters (six criteria). Each criterion can be expressed with five scores, three for acceptable and two for non-acceptable (one for reparable and one for replacement). The criteria have been used in several clinical studies since 2007, and the resulting experience in their application has led to a requirement to modify some of the criteria and scores. The two major alterations involve staining and approximal contacts. As staining of the margins and the surface have different causes, both phenomena do not appear simultaneously. Thus, staining has been differentiated into marginal staining and surface staining. The approximal contact now appears under the name "approximal anatomic form" as the approximal contour is a specific, often non-esthetic issue that cannot be integrated into the criterion "esthetic anatomical form". In 2008, a web-based training and calibration tool called e-calib (www.e-calib.info) was made available. Clinical investigators and other research workers can train and calibrate themselves interactively by assessing clinical cases of posterior restorations, which are presented as high quality pictures. Currently, about 300 clinical cases are included in the database which is regularly updated. Training for 8 of the 16 clinical criteria is available in the program: "Surface luster"; "Staining (surface, margins)"; "Color match and translucency"; "Esthetic anatomical form"; "Fracture of material and retention"; "Marginal adaptation"; "Recurrence of caries, erosion, abfraction"; and "Tooth integrity (enamel cracks, tooth fractures)". Typical clinical cases are presented for each of these eight criteria and their corresponding five scores. [ABSTRACT FROM AUTHOR]

Purpose: First, to elucidate the cause of the appearance of "white lines" in Class V restorations as seen under the light microscope and their enhancement when using a fluorescent microscope (FM); second, to compare the results of the FM quantitative marginal analysis to those of the SEM quantitative marginal analysis. Materials and Methods: Thirty-two standardized Class V fillings, with half of the preparation in dentin and half in enamel, were placed in 16 human caries-free premolars on the buccal and lingual surface using 4 adhesive systems (Clearfil SE, Syntac, 2 experimental self-etching adhesives) and the composite Tetric Ceram. All teeth were connected to a device containing horse serum to simulate dentinal fluid and subjected to thermomechanical loading (1,200,000 cycles at 49 N, 3000 cycles at 5°C/55°C). The restoration margins of 24 fillings were directly evaluated with FM -- after the fabrication of replicas -- and with SEM. Eight filllings were used to elucidate the cause of the fluorescent signal, by examining them with FM and different filters under dry and moist conditions, and also with dark field microscopy and CLSM. Further, two Class V fillings with the same composite but without the fluorescent substances were made and evaluated. Selected specimens were cut in the bucco-oral direction to analyze the restorative interface on section replicas with SEM. To detect differences between FM and SEM, the Wilcoxon test was performed (p < 0.05). To evaluate the degree of agreement between the two evaluation methods, a linear regression analysis was performed and the Spearman correlation coeffcient was calculated. Results: The evaluation of Class V restorative margins by SEM, dark field microscopy, and CLSM revealed that the phenomenon seems to be an optical effect caused by the debonding of the composite from the underlying substrate creating another refractive environment when air penetrates into the gap. The effect depends on the geometry of the cavity design, the absence of moisture, and the use of a fluorescent composite material. The light source that produced the best visible results covered both ultraviolet and the blue part of white light (350 to 460 nm), producing light green lines and green areas. Those green or white areas as seen with the light microscope were related to gaps in the interface between tooth substance and composite. With the exception of one of the experimental self-etching adhesives, the mean percentage of continuous margin of the 4 groups showed no statistically signifcant dfference for the two test methods. Linear regression analysis revealed a good correlation between the two test methods for dentin margins and a moderate correlation for enamel margins. Conclusion: Fluorescence microscopy seems to be a useful tool for evaluating dentinal and enamel margins of Class V restorations in vitro. [ABSTRACT FROM AUTHOR]

PURPOSE: To determine the influence of incorrectly performed steps during the application of the water-based adhesive system OptiBond FL on the marginal adaptation of Class V composite restorations. MATERIALS AND METHODS: In 96 extracted human teeth Class V cavities were prepared. Half of the margin length was situated in dentin. The teeth were randomly divided into 12 groups. The cavities were filled with Prodigy resin-based composite in combination with OptiBond FL according to the manufacturer's instructions (Group O) and including several incorrect application steps: Group A: prolonged etching (60 s); Group B: no etching of dentin; Group C: excessive drying after etching; Group D: short rewetting after excessive drying; Group E: air drying and rewetting; Group F: blot drying; Group G: saliva contamination; Group H: application of primer and immediate drying; group I: application of only primer; group J: application of only adhesive; Group K: no light curing of the adhesive before the application of composite. After thermocycling, replicas were taken and the margins were quantitatively analyzed in the SEM. Statistical analysis of the results was performed using non-parametric procedures. RESULTS: With exception of the "rewetting groups" (D and E) and the group with saliva contamination (G), all other application procedures showed a significantly higher amount of marginal openings in dentin compared to the control group (O). Margin quality in enamel was only affected when the primer was not applied. [ABSTRACT FROM AUTHOR]