Revised FDI criteria for evaluating direct and indirect dental restorations-recommendations for its clinical use, interpretation, and reporting.

OBJECTIVES: The FDI criteria for the evaluation of direct and indirect dental restorations were first published in 2007 and updated in 2010. Meanwhile, their scientific use increased steadily, but several questions from users justified some clarification and improvement of the living document. MATERIALS AND METHODS: An expert panel (N = 10) initiated the revision and consensus process that included a kick-off workshop and multiple online meetings by using the Delphi method. During and after each round of discussion, all opinions were collected, and the aggregated summary was presented to the experts aiming to adjust the wording of the criteria as precisely as possible. Finally, the expert panel agreed on the revision. RESULTS: Some categories were redefined, ambiguities were cleared, and the descriptions of all scores were harmonized to cross-link different clinical situations with possible management strategies: reviewing/monitoring (score 1-4), refurbishment/reseal (score 3), repair (score 4), and replacement (score 5). Functional properties (domain F: fracture of material and retention, marginal adaptation, proximal contact, form and contour, occlusion and wear) were now placed at the beginning followed by biological (domain B: caries at restoration margin, hard tissue defects, postoperative hypersensitivity) and aesthetic characteristics (domain A: surface luster and texture, marginal staining, color match). CONCLUSION: The most frequently used eleven categories of the FDI criteria set were revised for better understanding and handling. CLINICAL RELEVANCE: The improved description and structuring of the criteria may help to standardize the evaluation of direct and indirect restorations and may enhance their acceptance by researchers, teachers, and dental practitioners.

Evaluation of direct restorations using the revised FDI criteria: results from a reliability study.

OBJECTIVES: The purpose of this in vitro reliability study was to determine the intra- and inter-examiner agreement of the revised FDI criteria including the categories "fracture of material and retention" (F1) and "caries at restoration margin" (B1). MATERIALS AND METHODS: Forty-nine photographs of direct tooth-coloured posterior (n = 25) and anterior (n = 24) restorations with common deficiencies were included. Ten dental experts repeated the assessment in three blinded rounds. Later, the experts re-evaluated together all photographs and agreed on a reference standard. Statistical analysis included the calculation of Cohen's (Cκ), Fleiss' (Fκ), and weighted Kappa (wκ), the development of a logistic regression with a backward elimination model and Bland/Altman plots. RESULTS: Intra- and inter-examiner reliability exhibited mostly moderate to substantial Cκ, Fκ, and wκ values for posterior restorations (e.g. Intra: F1 Cκ = 0.57, wκ = 0.74; B1 Cκ = 0.57, wκ = 0.73/Inter F1 Fκ = 0.32, wκ = 0.53; B1 Fκ = 0.41, wκ = 0.64) and anterior restorations (e.g. Intra F1 Cκ = 0.63, wκ = 0.76; B1 Cκ = 0.48, wκ = 0.68/Inter F1 Fκ = 0.42, wκ = 0.57; B1 Fκ = 0.40, wκ = 0.51). Logistic regression analyses revealed significant differences between the evaluation rounds, examiners, categories, and tooth type. Both the intra- and inter-examiner reliability increased along with the evaluation rounds. The overall agreement was higher for anterior restorations compared to posterior restorations. CONCLUSIONS: The overall reliability of the revised FDI criteria set was found to be moderate to substantial. CLINICAL RELEVANCE: If properly trained, the revised FDI criteria set are a valid tool to evaluate direct and indirect restorations in a standardized way. However, training and calibration are needed to ensure reliable application.

Wear of an ion-releasing powder/liquid polymer resin in relation to that of glass-ionomer and conventional resin composites.

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 ion-releasing 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 resin-modified glass-ionomer cements was statistically significantly higher, between 616±44 µm (Ionofil Molar) and 946±101 µm (Fuji IX GP) than that of the ion-releasing polymer resin Cention N (327±63 µm) (ANOVA post-hoc Tukey B, P< 0.01), which was in the same statistical group of the conventional resin CeramX (323±31 µm). Filtek Z350 XT showed significantly lower wear (221±19 µm) (ANOVA post-hoc Tukey B, P< 0.05). The materials ChemFil Rock (39±13 µm), Photac Fil (41±9 µm), and Fuji II (42±8 µm) had the lowest antagonist wear, while Ketac Fil Universal (143±37 µm) and CeramX (135±13 µm) had the highest antagonist wear. Antagonist wear for Cention N was somewhere in between (90±21 µm). CLINICAL SIGNIFICANCE: For the restoration of posterior Class II and large Class I restorations, resin-based materials should be chosen over resin-modified or conventional glass-ionomer cements.

Press-on force during polishing of resin composite restorations.

OBJECTIVE: To measure the press-on force during the polishing of composite restorations carried out by 10 dentists in a clinically simulated procedure. METHODS: Composite restorations (Tetric EvoCeram Bulk Fill) were placed in standardized Class II two-surface cavities in first upper acrylic molars. The surfaces were roughened by sandblasting (50µm, 1bar). The tooth was mounted on a tailor-made device with a 3D force sensor (Kistler, Z21134-300, 10Hz). Ten dentists (7 male, 3 female) polished one Class II restoration each using the one-step polishing system OptraPol together with a dental handpiece and water spray. The dentists were allowed to use all shapes of the polishing system (small flame, large flame, cup, lens). During polishing, the press-on forces measured for up to 2 minutes. Simultaneously, the polishing procedure was recorded with a digital camera to correlate the forces with the polishing shapes and movements. RESULTS: In total, 17,999 force measurements were available for analysis. The mean forces of all operators varied between 0.77(±0.63) N and 2.23(±1.48) N; the difference was statistically significant (ANOVA, post-hoc Tukey B, p<0.05). All dentists exerted maximum forces higher than 3 N (between 3.3N and 18.3N). Force values exceeded 2N during 25% of the polishing time. Female dentists polished with a statistically significant lower force than male dentists (ANOVA, p<0.001). Polishing with the large flame and the cup generated significantly higher forces than polishing with the small flame and the lens (ANOVA, post hoc Tukey B, p<0.01). CONCLUSIONS: The press-on forces applied during polishing varied significantly between dentists and within the same dentist. In about 25% of the polishing time, forces were above the 2N limit, which is recommended by some manufacturers as the maximum polishing force. Test institutes and manufacturers should evaluate the polishing performance of polishing instruments with various press-on forces.

Marginal Quality of Class II Composite Restorations Placed in Bulk Compared to an Incremental Technique: Evaluation with SEM and Stereomicroscope.

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.

FDI World Dental Federation - clinical criteria for the evaluation of direct and indirect restorations. Update and clinical examples.

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.

FDI World Dental Federation: clinical criteria for the evaluation of direct and indirect restorations-update and clinical examples.

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 has 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 eight of the 16 clinical criteria is available in the program: "Surface lustre"; "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.

Ceramics as biomaterials for dental restoration.

Sintered ceramics and glass-ceramics are widely used as biomaterials for dental restoration, especially as dental inlays, onlays, veneers, crowns or bridges. Biomaterials were developed either to veneer metal frameworks or to produce metal-free dental restorations. Different types of glass-ceramics and ceramics are available and necessary today to fulfill customers' needs (patients, dentists and dental technicians) regarding the properties of the biomaterials and the processing of the products. All of these different types of biomaterials already cover the entire range of indications of dental restorations. Today, patients are increasingly interested in metal-free restoration. Glass-ceramics are particularly suitable for fabricating inlays, crowns and small bridges, as these materials achieve very strong, esthetic results. High-strength ceramics are preferred in situations where the material is exposed to high masticatory forces.

Fluorescence microscopy for the evaluation of the margins of Class V restorations in vitro.

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 degrees C/55 degrees C). The restoration margins of 24 fillings were directly evaluated with FM--after the fabrication of replicas--and with SEM. Eight fillings 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.