Operative dentistry最新文献

This study evaluated the microleakage in zirconia crowns cemented with bioactive vs resin cements at two margin locations: cementum/dentin deep margin and composite-elevated margins. Standardized mesial box cavities were prepared in 30 molar teeth, with proximal cavosurface margins placed 1 mm below the cemento-enamel junction (CEJ) and restored with resin composite. The teeth were prepared for zirconia crowns, with mesial margins on the composite and distal margins on tooth structure 1 mm below the CEJ. Following digitization and zirconia crown fabrication, the specimens were randomly allocated into five groups based on the type of cement used: one multistep adhesive resin, one self-adhesive resin, one bioactive hybrid ionic resin, and two bioceramic cements. Microleakage was evaluated by measuring the percentage of dye penetration depth at the interfaces, with data analyzed using two-way ANOVA. The results revealed a significant interaction between cement type and margin location, with elevated margins exhibiting less leakage than deep ones across all cement types (p≤0.001). However, the effect of margin location on microleakage varied depending on the cement type, with variations in microleakage scores at each margin location ranging from statistically nonsignificant (p>0.05) to statistically significant (p≤0.05). Adhesive resin and hybrid bioactive cements significantly outperformed others in reducing microleakage at both margin interfaces.

The patient underwent combined orthodonticorthognathic surgical treatment due to her skeletal Class III malocclusion. In the first phase, orthodontic decompensation was performed with maxillary and mandibular fixed appliances. The maxillary first premolars were extracted; the created space was closed by anterior retraction. The posterior anchorage was reinforced with interradicular temporary anchorage devices. In the second phase, a digital surgical treatment plan was made with intra- and extraoral simulation (including occlusion and profile). During the orthognathic surgery, a bilateral sagittal split osteotomy with mandibular setback was combined with maxillary movements, using 3D-printed surgical splints. In the third phase, the orthodontic treatment continued to finish and settle the occlusion. Spaces were created between the upper incisors for ceramic veneers to gain proper overjet and occlusion. The last phase was prosthetic and esthetic rehabilitation. During the planning, a 2Dand 3D-smile design was created and presented to the patient as a mock-up. After digital impression and design, four E-max veneers were milled and cemented using dual cement to finish the workflow. Retention splints were created to preserve the new status as a final step.

The purpose of this study was to investigate the effect of chitosan-added experimental nanohydroxyapatite (n-HA) gel on the physical and morphological changes of the enamel surface after the use of two different vital bleaching agents. Fifty-two intact, caries-free human maxillary incisors were embedded in acrylic resin. Chitosan-added n-HA powder was synthesized using a high-temperature oxidation method and then mixed with phosphate-buffered saline solution (PBS) to form a gel. The teeth were divided into four groups: Group B: Biowhiten in-office 40% n-HP (BioWhiten, Biodent Ltd, Istanbul, Turkey); Group O: Opalescence Boost 40% HP (Ultradent Products Inc., South Jordan, UT, USA); Group BN: Biowhiten in-office 40% n-HP+n-HA gel; Group ON: Opalescence Boost 40% HP+n-HA gel. Color change, surface microhardness, and surface roughness (Ra) measurements were taken before, immediately after, and one week after bleaching. Three specimens from each group were also subjected to scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDS) analysis. The data were statistically analyzed using an analysis of variance (ANOVA) and Bonferroni post hoc test (p<0.05). After bleaching, all groups showed a noticeable change in color (p<0.05), but with no differences among the treatment groups (p>0.05). After bleaching, the highest Ra values were determined in Group O (p<0.05). Group ON showed a statistically lower Ra value than Group O (p<0.05). The lowest microhardness value after bleaching was observed in Group O (p<0.05), which also had the lowest calcium/phosphorus (Ca/P) value. After the experimental chitosan-added n-HA gel application, the Ca/P ratio increased. The use of experimental chitosan-added n-HA gel after bleaching improved the physical and morphological properties of the enamel surface without reducing the effectiveness of bleaching.

Objective.: This study evaluated the effect of filler content and composition on the radiopacity of different resin-based materials used to cement fiberglass posts (dual-cure resin cements or dual-cure resin core materials) and build the core (bulk-fill or dual-cure core resin composites) to restore endodontically treated teeth.

Methods and materials.: Nine resin-based materials were tested: Four dual-cure resin core materials: Allcem Core, FGM; LuxaCore Z, DMG; Rebilda DC, VOCO; and Clearfil DC Core Plus, KURARAY; three dual-cure resin cements: RelyX Universal, 3M Oral Care; RelyX U200, 3M Oral Care; and Allcem Dual, FGM; and two bulk-fill resin composites: OPUS Bulk Fill APS, FGM; and Filtek One Bulk Fill, 3M Oral Care. Thermogravimetric analysis (TGA, %) was performed to determine the filler content. Scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) were used to evaluate the filler morphology and composition. Radiopacity was measured using digital radiographs (n=10) according to ISO 4049 standards. TGA and radiopacity data were subjected to a one-way analysis of variance (ANOVA) followed by a Tukey post hoc test (α=0.05).

Results.: Except for Luxacore Z, the dual-cure resin core materials and bulk-fill resin composites had higher filler contents than the dual-cure resin cements (p<0.001). Allcem Core exhibited more homogeneous fillers without agglomerates, whereas RelyX Universal presented only nanoparticles. OPUS Bulk Fill APS, Allcem Dual, and Allcem Core, made by the same manufacturer, presented similar sizes, shapes, and distributions of filler content. EDS analysis revealed that oxygen O (8), Si (14), C (6), Al (13), and Ba (56) were the most prevalent elements. The radiopacity of the tested materials is related to the presence of high atomic number elements such as Yr (70), La, (57), Ba (56), Zr (40), Sr (38), and Br (35) in their filler composition. All materials satisfied the ISO 4049 radiopacity requirements.

Conclusions.: Results were product-specific. Except for LuxaCore Z and Allcem Core, dual-cure resin core materials exhibited filler content similar to that of bulk-fill resin composites and higher than that of dual-cure resin cements. All materials exceeded the ISO 4049-2019 standard for radiopacity of restorative materials.

This comparative in vitro study evaluated surface treatment methods for chairside CAD/CAM lithium disilicate enriched with virgilite using atomic force microscopy (AFM) imaging. Specimens were fabricated from two lithium disilicate materials: the traditional material (IPS e.max CAD, Ivoclar Vivadent, Schaan, Liechtenstein) and a virgilite-containing material (CEREC Tessera, Dentsply Sirona, Charlotte, NC, USA). Surface roughness (Ra) [in micrometers (μm)] was quantitatively assessed with AFM. The results demonstrated that IPS e.max CAD with glazing exhibited the smoothest surface with the lowest Ra values (10.03 ± 5.03 μm). In contrast, CEREC Tessera exhibited the highest surface roughness when treated with glazing (51.98 ± 12.31 μm), while the zirconia polishing system provided a smoother surface (15.44 ± 9.69 μm).

Objectives: Simplified application and caries preventive features are desired properties for an ideal dental restorative material. Therefore, the aim of this study was to evaluate the clinical performance of a newly developed bioactive alkasite-based resin composite (Cention Forte, Ivoclar Vivadent, Schaan, Liechtenstein) with these properties.

Methods: Vital teeth with class I or II restoration need were included in the study. A total of 49 patients received 90 posterior restorations. Extension for retention and beveling were avoided during cavity preparation. The primer (Cention Primer, Ivoclar Vivadent) for alkasite restorative materials was applied prior to restoration placement. Two independent observers made the evaluations using the FDI criteria (scores 1-5) for esthetic, functional, and biological properties. Patients were recalled after three to four weeks (baseline) and one year. Wilcoxon signed rank test was used to evaluate the differences between FDI scores at baseline and after one year.

Results: Ninety restorations at baseline and 86 restorations at one year were evaluated. The overall success rate of the restorations was 98.8%, and the overall survival rate was 100% after one year in function. Only one restoration was clinically unacceptable (FDI score 4) due to a small material chip after one year.

Conclusions: Quality of the restorations was unaffected in terms of marginal adaptation, marginal discoloration, and secondary caries formation, whereas color and surface luster of the restorations deteriorated slightly over time. No retention loss or tooth fracture was observed.