SUMMARY Objectives: The case report describes a minimally invasive, multidisciplinary approach to a single discolored anterior tooth, with internal bleaching using traditional Japanese paper (Washi), a gingivoplasty with a three-dimensional (3D) printed surgical guide, and ultrathin feldspathic porcelain veneers. Clinical consideration: The patient’s primary concern was improving her smile. After clinical evaluation, internal tooth bleaching for the discolored tooth and gingivoplasty with restoration of the maxillary anterior six teeth and first premolars was recommended. The internal tooth whitening was accomplished with sodium perborate mixed with 30% hydrogen peroxide impregnated in Washi and sealed in the root canal with glass ionomer. Once the tooth bleaching was completed, the 3D printed surgical guide was placed in the patient’s maxillary anterior region and used to guide soft tissue recontouring. After 6 months, ultrathin feldspathic porcelain veneers were placed. Conclusion: Well-planned restorative procedures combining internal tooth bleaching using Washi, gingivoplasty performed with electrosurgery using a 3D printed surgical guide, and ultrathin feldspathic porcelain veneers can achieve the desired results in the esthetic zone and remain successful for 4 years.
SUMMARY Objective: The purpose of this study was to evaluate the effectiveness of five different polishing systems on a computer-aided design and computer-aided manufacturing (CAD/CAM) polymer-infiltrated ceramic-network restoration with nanoscale assessment using atomic force microscopy (AFM) and visual assessment performed by dental school senior students and faculty members. Method: Forty-eight full coverage crowns were milled out of polymer-infiltrated ceramic-network CAD/CAM blocks (Vita Enamic) for polishing with one company proprietary, two ceramic and two composite polishing systems. The prepared crowns were divided into six groups: (1) no polishing (control); (2) polishing with Vita Enamic Polishing Kit (VEna); (3) polishing with Shofu Porcelain Laminate Polishing Kit (SCer); (4) polishing with Brasseler Dialite Feather lite All-Ceramic Adjusting & Polishing System (BCer); (5) polishing with Shofu Composite Polishing Kit (SCom); and (6) polishing with Brasseler Composite Polishing Kit (BCom). The polished crown surface topography was observed, and surface roughness and area were measured with AFM. In addition, polished crowns were visually assessed by 15 senior dental students and 15 dental school faculty members. Results: All polishing treatments significantly reduced the surface roughness and area of the crown compared with the control. SCom and BCom showed significantly higher surface area than VEna, and the SCer and BCer groups were intermediate, showing no significant difference from either VEna or SCom and BCom. There were no significant differences in surface roughness between any of the systems. Dental students and faculty members classified the groups polished with VEna, SCer, and BCer groups as clinically acceptable, and they selected BCer group as the best polished restorations and the control group as the least polished restorations. Conclusions: Ceramic and composite polishing systems produced similar polishing results as that observed using a company proprietary polishing system. However, effectiveness for polishing using a company proprietary and ceramic polishing system tends to be higher than composite polishing systems.
Clinical Relevance The use of layering techniques is still advisable with many bulk-fill resins and should be the default unless a particular resin is known to not need it. SUMMARY Objective: The purpose of this study was to investigate how layering techniques affect polymerization shrinkage stresses of high-and low-viscosity bulk-fill resins. Method: Six high-viscosity and six low-viscosity bulk-fill resins were evaluated. Aluminum blocks with a mesial-occlusal-distal (MOD) cavity were machined and randomly divided into groups for different filling techniques (bulk-fill vs horizontal layering vs oblique layering) and further subdivided according to type of resin (high- vs low-viscosity). The cuspal deflection resulting from the polymerization of bulk-fill resin bonded to a MOD cavity within an aluminum block was measured with a digimatic micrometer. Scanning electron microscopy analyses of tested resins were also conducted. Results: In the high-viscosity bulk-fill resins, cuspal deflection of the MOD cavity ranged from 11.2 to 18.2 μm with the bulk-filling technique, from 10.7 to 15.5 μm with the horizontal layering technique, and from 10.9 to 15.2 μm with the oblique layering technique. In the low-viscosity bulk-fill resins, cuspal deflection of the material ranged from 9.2 to 19.8 μm with the bulk-filling technique, from 8.2 to 15.7 μm with the horizontal layering technique, and from 8.4 to 16.4 μm with the oblique layering technique. Conclusion: Cuspal deflections for some high-and low-viscosity bulk-fill resins were significantly reduced by using layering techniques, but the resultant improvement of layering techniques was not applicable to all the bulk-fill resins used in this study.
Clinical Relevance This study investigated the interface of different self-etching systems with dentin and showed that the intensity of interaction was mostly dependent on the acidity of the primers/adhesives used. ßSUMMARY This in vitro study evaluated the resin-dentin interface formed by two 2-step and two 1-step self-etching adhesive systems under SEM. Class V cavities (4 × 2.5 × 1.5 mm) were prepared on the buccal surfaces of 25 extracted intact human third molars using a carbide bur in a high-speed handpiece. Four self-etching systems with corresponding resins were used: two 2-step systems, AdheSE (Ivoclar Vivadent) and Contax (DMG Hamburg), one 1-step/2 components system Futurabond NR (Voco) and a 1-step/1 component adhesive G-Bond (GC Corp). An etch and rinse system, PQ Clear (Ultradent), was used as a control. The teeth were thermocycled (500 cycles, 5°/55°C, 30 seconds dwell time), and 2 sections were made longitudinally through the restorations with a low-speed diamond saw, producing approximately 1-mm wide samples. The samples were polished with silicon carbide paper of increasing grit (400–1000), demineralized (6N HCl, 30 seconds), deproteinized (2.5% NaOCl, 10 minutes), left to air dry for 24 hours in a desiccator under low vacuum pressure, gold sputtered and viewed under SEM (JEOL-JSM-6460LV). In the AdheSE, Contax and Futurabond NR specimens, resin tag penetration into the tubules and lateral tags could be seen. G-Bond showed different interface morphology, with a tight, thin continuous junction and almost no resin penetration into tubules. PQ Clear samples exhibited the highest number of resin tags with numerous lateral tags. A clearly defined hybrid layer was seen in the Contax and PQ Clear specimens. Investigated self-etching systems showed similar interfacial morphology with dentin, except for the 1 step/1 component adhesive G-Bond. The degree of demineralization and interaction with dentin correlated with the acidity of the self-etching primers/adhesives. Fewer resin tags were formed with self-etching primers/adhesives than with the etch and rinse system.
Clinical Relevance Beverages, such as wine or coffee, and bleaching agents result in decreases in composite surface microhardness from baseline values. SUMMARY This study investigated the effect of 3 staining solutions and 3 over-the-counter tooth-bleaching systems on the microhardness of 2 dental resin composites. Forty-five specimens of Filtek Supreme and Esthet-X were randomly assigned to 3 groups. Over a 40-day test period, the specimens in each group (n=15) were immersed in 1 of the 2 staining solutions (coffee and red wine) or distilled water as the control for 3 hours a day at room temperature. The 15 specimens in each staining group were further randomly divided into 3 subgroups, and the specimens in each subgroup (n=5) were bleached using one of the bleaching agents (Night Effects, Simply White Night and Opalescence Quick). Surface hardness was measured at 24 hours after polymerization (baseline), after staining and after bleaching. Means and standard deviations were calculated, and the data were analyzed using repeated-measures analysis of variance and Duncan's Test. The microhardness of Esthet-X was significantly higher than Filtek Supreme at baseline ( p <0.01). All specimens of both materials immersed in coffee and wine revealed a significant hardness decrease compared to baseline values ( p <0.05). In the control group, microhardness was increased, and this increase was statistically significant for Filtek Supreme ( p <0.05). After bleaching, there was a significant decrease in mean microhardness for all groups tested ( p <0.05). No significant difference was found among bleaching agents.