Luiz Henrique Burnett Júnior

The aim of this study was to evaluate, in vitro, the void formation and marginal adaptation in Class II cavities restored with preheated and injected bulk-fill resin composites. Eighty third molars received Class II cavities on their mesial and distal surfaces and were randomly distributed into eight groups (n = 10) according to material (Filtek Universal—control, incremental technique; Filtek One Bulk-Fill; Admira Fusion X-tra Bulk-Fill; VisCalor Bulk-Fill) and the temperature of the material (24 °C or 68 °C). The restored teeth were scanned using a SkyScan 1173 microtomograph. The percentage of internal voids (%IV) was analyzed using CTan software (version 1.23.02) and the percentages of continuous margins (%CM) in enamel and dentin were analyzed using Dataviewer software (version 1.5.6.2). The data of %IV and %CM were subjected to two-way ANOVA on ranks, followed by Tukey’s test (α = 0.05). At 24 °C, Filtek Universal had a greater %IV (1.89%) (p < 0.05), which did not differ significantly from that of Admira Fusion X-tra Bulk-Fill (0.29%) (p > 0.05). Filtek One Bulk-Fill (0.07%) and VisCalor Bulk-Fill (0.07%) had lower %IV (p < 0.05). Preheating resulted in a significantly lower %IV for Admira Fusion X-tra Bulk-Fill (p < 0.05). Temperature did not significantly influence marginal adaptation (p > 0.05). VisCalor Bulk-Fill achieved significantly higher %CM in dentin (98%) at 24 °C (p < 0.05). It was concluded that bulk-fill-injected resin composites tend to have fewer internal voids than conventional resin composites using the incremental technique, and the injection of the resin composite into the cavity seems to be more important for marginal adaptation than the preheating procedure.

Objetive This study aimed to evaluate, in situ, the microbiological composition of the biofilm formed on intraradicular posts attached to removable intraoral devices. Methods For this, ten participants wore an upper intraoral device containing three types of intraradicular posts nickel-chromium metal, fiberglass, and acrylic resin-over twenty-eight days. The posts were fixed to the device palatally and with the long axis parallel to the longitudinal axis of the acrylic. Throughout the experimental period, all participants were instructed to follow the same oral hygiene and device care pattern. After this period of use, a portion of the post-samples was evaluated to quantify the number of microorganisms using the culture method. The other portion of the posts was analyzed through scanning electron microscopy to assess microbial colonization. The data obtained were recorded in an Excel spreadsheet and subjected to Kruskal-Wallis and Dunn statistical analyses. Results No statistically significant difference was observed between the posts and the different media. All posts showed contamination in all media. Microbial colonies were identified through Scanning Electron Microscopy on all three intraradicular posts analyzed. Conclusion Posts exposed in the oral cavity for twenty-eight days demonstrate a high microbial load regardless of their composition.

Bem vindo ao DentalGO a plataforma online dos melhores dentistas

This study aimed to compare the accuracy of full-arch digital implant impressions using seven different scanbodies and four intraoral scanners. A 3D-printed maxillary model with six implants and their respective multi-unit abutments was used for this study. Seven scanbodies (SB1, SB2, SB3, SB4, SB5, SB6, and SB7) and four intraoral scanners (Primescan®, Omnican®, Trios 3®, and Trios 4®) were assessed. Each combination group was scanned ten times and a dental lab scanner (D2000, 3Shape) was used as a reference. All scans were exported as STL files, imported into Convince software (3Shape) for alignment, and later into Blender software, where their 3D positions were analyzed using a Python script. The 3D deviation, angular deviation, and linear distance between implants #3 and #14 were also measured. Accuracy was measured in terms of “trueness” (scanbody 3D deviation between intraoral scan and desktop scan). Kruskal-Wallis followed by the Bonferroni correction was used to analyze the data (⍺ = .05). The study found statistically significant differences in digital impression accuracy among the scanners and scanbodies (p<0.001). When comparing different intraoral scanners, the Primescan system showed the smallest 3D deviation (median 110.59 μm) and differed statistically from the others, while Trios 4 (median 122.35 μm) and Trios 3 (median 130.62 μm) did not differ from each other (p = .284). No differences were found in the linear distance between implants #3 and #14 between Trios 4, Primescan, and Trios 3 systems. When comparing different scanbodies, the lowest median values for 3D deviation were obtained by SB2 (72.27μm) and SB7 (93.31μm), and they did not differ from each other (p = .116). The implant scanbody and intraoral scanner influenced the accuracy of digital impressions on completely edentulous arches.

The purpose was to evaluate, in vitro, the fracture strength of teeth restored with 0.3- or 0.6-mm-thick occlusal veneers made of Vita Enamic® bonded to enamel or dentin. Fifty third molars were allocated into five groups (n=10): Group C - control (sound teeth); Group 0.3E - 0.3-mm-thick occlusal veneers bonded to enamel; Group 0.6E - 0.6-mm-thick occlusal veneers bonded to enamel; Group 0.3D - 0.3-mm-thick occlusal veneers bonded to dentin; Group 0.6D - 0.6-mm-thick occlusal veneers bonded to dentin. After luting with Single Bond Universal and Filtek Z-100, the samples were subjected to fracture strength test in a universal testing machine. The fractures were classified as irreparable and reparable. Data were analyzed with 2-way and 1-way ANOVA (α=.05) followed by Tukey’s test. The teeth restored with 0.3-mm-thick occlusal veneers (2658 N) achieved significantly higher fracture strength compared to the teeth restored with 0.6-mm-thick occlusal veneers (2070 N) (p=0.017). The teeth restored with occlusal veneers bonded to enamel (2648 N) had significantly higher fracture strength compared to the teeth restored with occlusal veneers bonded to dentin (2049 N) (p=0.015). Group C (3355 N) and Group 0.3E (2965 N) did not differ significantly from each other, being the fracture strength significantly higher than the other groups (p<0.05). The fractures were predominantly reparable. The teeth restored with 0.3-mm-thick occlusal veneers achieved higher fracture strength compared to the teeth restored with 0.6-mm-thick occlusal veneers. The supporting substrate influenced the fracture strength, which was higher for the teeth restored with occlusal veneers bonded to enamel.

To evaluate whether dental crown topography influences the fracture resistance of premolars treated endodontically and with MOD preparation subjected to different restorative protocols. Sixty‐four human premolars with one or two roots in equal numerical proportions (n) were selected and randomly divided into four groups (n = 8): (S = single‐rooted; D = double‐rooted) SS: sound single‐rooted; SNR: endodontics (E) + MOD cavity preparation; SR: E + MOD + resin restoration (RS); SP: E + MOD + RS + horizontal zirconia post (ZP); DS: sound double‐rooted; DNR: E + MOD; DR: E + MOD + RS; and DP: E + MOD + RS + ZP. After allocation to the groups, the samples were thermocycled and then subjected to the fracture resistance test. Failures after the fracture test were classified as irreparable (with pulp floor fracture) or reparable (without pulp floor fracture). Data were analysed using one‐way anova and the Tukey test (α = 0.05). Single‐rooted premolars were more resistant to fracture than double‐rooted premolars. The restorative treatment using a horizontally transfixed zirconia post improved fracture resistance, resembling that of a healthy tooth.

To assess whether access cavity design influences the fracture strength of endodontically treated and restored molars. Fifty human lower molars with standard crown dimensions were selected and assigned to the following groups: S – positive control (healthy tooth), ET – negative control (conventional endodontic access (CEA) and no restoration), NI – negative control (minimally invasive endodontic access (MEA) and no restoration), ETR (CEA + restoration with Bulkfill flow) and NIR (MEA + restoration with Bulkfill flow). The specimens were subjected to a compression test. The teeth were inspected for the site of fracture: either pulp floor or cusp. ANOVA, followed by Tukey’s multiple comparison test (α = 5%), was used for statistical analysis. The type of access cavity preparation did not increase the fracture strength of endodontically treated teeth. Even with the restoration, all teeth with endodontic access performed had a higher incidence of fractures at the pulp chamber floor level.

SUMMARY: The aim was to evaluate, in vitro, the influence of different computer-aided design/computer-aided manufacturing (CAD/CAM) materials (IPS e.max CAD, Vita Enamic, and Lava Ultimate) and thicknesses (0.6 mm and 1.5 mm) on the fracture resistance of occlusal veneers. Sixty human third molars were prepared to simulate advanced erosion of the occlusal surface, and the teeth were randomly divided into six experimental groups (n=10) according to the material and thickness used to build the veneers. Ten sound teeth formed the control group. The veneers were adhesively luted and submitted to mechanical cyclic loading (1 million cycles at 200-N load). The fracture resistance test was performed in a universal testing machine. The failures were classified as “reparable” and “irreparable.” According to two-way analysis of variance and the Tukey test, the interaction (material × thickness) was significant (p=0.013). The highest fracture resistance was obtained for IPS e.max CAD at a 1.5-mm thickness (4995 N) and was significantly higher compared to the other experimental groups (p0.05). The experimental groups did not differ significantly from the sound teeth (3991 N) (p>0.05). The failures were predominantly repairable. The occlusal veneers of IPS e.max CAD, Vita Enamic, and Lava Ultimate, with thicknesses of 0.6 mm and 1.5 mm, obtained fracture resistances similar to those associated with sound teeth.

Background: Bruxism is defined as a repetitive activity of grinding the teeth through lateral or protrusive movements of the mandible, and it is considered the most complex and destructive functional disorder. In addition, erosion caused by diet or reflux can damage the remaining teeth. Objective: In this report, a patient with bruxism and dental erosion was treated with a multidisciplinary approach to restore the function and aesthetic. Methods: This clinical report describes the management of an adult woman, 33 years old, who was dissatisfied with the aesthetics of her smile and complained of joint pain and headaches. As result of her condition, the patient's dentition exhibited generalized wear on the vestibular and incisal surface of the upper incisors incompatible with her age, moderate darkening of the teeth and excess gingival tissue in the upper incisors. After a detailed anamnesis and clinical examination, a diagnosis of bruxism and acid erosion caused by a diet rich in citrus foods and beverages was obtained. Forthwith, a treatment plan was established, and the patient underwent home bleaching, gingivoplasty and ceramic laminates of lithium disilicate on the anterior teeth. After the rehabilitation was completed, a night guard was made to reduce the symptoms of bruxism and avoid fracture of the ceramic restorations. The patient was followed at different time intervals. Conclusion: The improvement in the aesthetics of the teeth was significant and remained stable after periodic controls in which no adverse effects were observed.