Operative dentistry最新文献

The aim of this this study was to evaluate the surface roughness and color stability of resin composites (RCs) with color adjustment potential (CAP): Omnichroma (OM), (Tokuyama Dental, Tokyo, Japan); Neo Spectra ST (NS) (Dentsply Sirona, York, PA,USA); and Charisma Diamond One (CD) (Kulzer, Hanau, Germany), compared to a conventional RC, Filtek Z350XT (FZ) (3M ESPE, St. Paul, MN,USA), after immersion in three staining solutions, cola, coffee, and black tea, with distilled water as a control. Forty specimens (8 mm diameter x 2 mm thickness) were prepared for each RC material and divided into subgroups (n=10/group) based on the immersion solution. Surface roughness was measured at baseline and after 21 days of immersion using a non-contact optical profilometer. Color change (ΔE00) was evaluated at baseline, 1, 7, and 21 days with a spectrophotometer. The results showed that FZ demonstrated the lowest surface roughness (0.14), significantly differing from that of the other RCs with CAP (p<0.05), while no significant differences in surface roughness were observed between RCs with CAP (p>0.05). There were no significant changes in surface roughness before and after immersion in various solutions. The results for color change (ΔE00) were statistically significant. Neo Spectra ST showed the lowest tendency for color change, while Filtek Z350XT displayed a moderate potential, and Omnichroma and Charisma Diamond One showed the highest potential for color change.

Objective: Systematic review and meta-analysis on laboratory studies aimed to answer whether there is a difference in fracture resistance and fracture mode of structurally compromised teeth restored with direct composite restorations reinforced with short glass-fiber or bidirectional polyethylene fiber substructure, and between the two different fiber-reinforcement types.

Methods: An electronic literature search was conducted in Medline, Scopus, Web of Science, Lilacs, Google Scholar, Cochrane Library, and University Library databases. The last search was conducted on 16 November 2023. Only studies looking at Ribbond-reinforced restorations and/ or the use of EverX Posterior within restorations were included. Data were categorized and analyzed based on specific outcome measures including fracture resistance and fracture mode. Data from individual studies were divided into premolars and molars for each material category and then collated to compare the mean differences in fracture resistance between control groups (composite restorations) and intervention groups (fiber-reinforced composite restorations).

Results: From the initial 1266 articles identified, 23 laboratory-based studies were included for quantitative analysis. Twenty articles had an overall low risk of bias and 3 had an overall unclear risk of bias. The pooled estimate of the effect favored the intervention groups as having statistically significant higher fracture resistance when compared to control groups.

Conclusions: Both fiber types improve fracture resistance and the fracture mode of structurally compromised teeth is equally efficient. Application technique deserves attention. Ribbond could be placed in a single layer at the cavity floor, whereas EverX Posterior should replace missing dentin in an anatomically shaped way.

Introduction: The aim of this study was to evaluate the effects of fluoride-containing remineralization agents on enamel white spot lesions.

Methods and materials: Twenty bovine incisors were cut mesio-distally and occluso-gingivally, creating 80 specimens, and divided into four groups (n=20/group): 1) control (no treatment); 2) fluoride varnish (Voco Profluoroid 5% NaF Varnish, VOCO Dental, Cuxhaven, Germany); 3) CPP-ACFP (MI Paste Plus with Recaldent, GC Corporation, Tokyo, Japan),; 4) self-assembling peptide (P11-4F, CURODONT Repair Fluoride Plus, Credentis AG, Windisch, Switzerland). After a three-week demineralization-remineralization cycle, white spot lesions were observed on the specimens. Before applying the remineralization agents, baseline demineralization values were determined using DIAGNOdent 2095, QLF-D Biluminator, SEM-EDS (KaVo Dental, Charlotte, NC, USA), and color values were measured by Vita EasyShade (Vita Zahnfabrik, Bad Säckingen, Germany). Remineralization agents were applied once, following the manufacturers' instructions. The remineralization capacities of these agents and their effects on color change were evaluated at four time points: baseline (T0), demineralization (T1), and remineralization on the seventh (T2) and 30th (T3) days.

Results: After 30 days, CPP-ACFP and P11-4F showed significantly greater Ca (% by weight), F (% by weight), and Ca/P ratio than the fluoride varnish group (p<0.05). SEM images revealed that in the groups where the remineralization agent was applied, the pores and tubules were blocked, and the surfaces were covered, whereas these findings were not observed in the control group. Based on QLF-D Biluminator data, P11-4F application provided more successful fluorescence changes compared to CPP-ACFP and fluoride applications and was statistically more effective in reducing lesion volume and maximum fluorescence loss (p<0.05). Significant differences were observed among the four groups at the seventh (T2) and 30th days (T3) in the laser fluorescence evaluation with DIAGNOdent (p<0.05). On the seventh day, the fluoride group exhibited greater effectiveness than the control group, while on the 30th day, the CPPACFP group demonstrated superior improvement over the control group (p<0.05). According to color change results, applying a remineralization agent was found to be a statistically successful method in restoring the tooth's original color (p<0.05). However, there were no significant differences among the treatment groups (p>0.05).

Conclusions: CPP-ACFP and P11-4F demonstrated positive effects on remineralization at the seventh and 30th days. Applying a remineralization agent is a viable option for blocking pores and tubules on demineralized enamel. The color change related to the use of the remineralization agent showed a positive effect over time.

Objective: This study aimed to assess the fracture resistance of chairside computer assisted design and computer assisted manufacturing (CAD-CAM) lithium disilicate partial and full-coverage crowns and veneers for maxillary canines.

Methods and materials: Forty-eight restorations for maxillary right canines (12 per group) were designed as follows: (1) partial crown with finish line in the upper middle third; (2) partial crown with finish line in the lower middle third; (3) traditional labial veneer; and (4) traditional full-coverage crown. Restorations were fabricated out of lithium disilicate (Amber Mill, Hassbio) using a chairside CAD-CAM system (Cerec Dentsply Sirona). Partial and full crowns and veneers were treated with a primer system (Monobond Plus, Ivoclar Vivadent) and cemented using dual-cure resin cement (Variolink Esthetic, Ivoclar Vivadent) and cemented to printed resin dies. Subsequently, the restorations were subjected to 10,000 thermocycles between 5°C and 55°C with a dwell time of 30 seconds. The restorations were then loaded axially on the incisal edge in compression to fracture with a flat indenter.

Results: Full-coverage crowns displayed the highest fracture resistance (809±28.57 N) followed by partial crowns with finish line in lower third (649±21.74 N) and crowns with finish line in upper third (421±17.46 N). Veneers displayed the lowest fracture resistance values (259±15.69 N).

Conclusions: The fracture resistance of partial and full-coverage crowns and veneers was significantly influenced by the design. Full coverage crowns displayed the highest fracture resistance and partial crowns showed higher fracture resistance than traditional veneers.

Adhesive dentistry has undergone significant advancements since its inception, marked by continuous improvements in material performance and adaptability to various dental and restorative substrates. Initially, the anatomical differences between enamel and dentin made adhesive approaches challenging. Early systems were often complex and operator dependent, leading to the development of multistep protocols. However, advancements have led to the creation of more user-friendly self-etch systems and the emergence of universal adhesives (UAs). These UAs can be applied with equal effectiveness to different substrates, including enamel and dentin, simplifying the clinical workflow and enhancing reliability. The concept of universality has recently been extended to other dental materials, most notably universal resin cements. These cements offer a versatile approach as they are capable of both adhesive and self-adhesive bonding, thereby accommodating a wide range of restorative scenarios. The advent of these materials represents a significant advance toward simplifying procedures, reducing technique sensitivity and the likelihood of operator error, and achieving consistently high quality restorations. Current research focuses on further refining these universal materials to enhance their performance, making them a cornerstone of modern adhesive dentistry.

Physical and mechanical properties of high-viscosity bulk-fill resin composites submitted to additional polymerization for semi-direct use were evaluated. Filtek Z350 XT, Aura Bulk Fill, Beautifil Bulk Restorative, Filtek One Bulk Fill Restorative, and Tetric N-Ceram Bulk Fill were submitted to additional polymerization to evaluate sorption, solubility, surface microhardness, surface roughness before and after simulated brushing, color stability after coffee staining, flexural strength, elastic modulus, and modulus of resilience. Filtek Z350 XT and Filtek One Bulk Fill Restorative showed higher sorption values, while Aura Bulk Fill showed higher solubility (p<0.0001). Microhardness values were significantly higher for Filtek Z350 XT (p<0.0001). Roughness increased after wear for all resins (p<0.05). All resins exhibited staining, with significantly higher ΔEab, ΔE00, and ΔWID values observed for Beautifil Bulk Restorative (p<0.0001). Flexural strength values were higher for Filtek Z350 XT and Filtek One Bulk Fill Restorative in comparison with the others (p<0.0001). Filtek One Bulk-Fill had higher elastic modulus and modulus of resilience values (p<0.0001). Physical and mechanical properties varied according to the composition. None of the bulk-fill resins showed surface microhardness and roughness properties after brushing similar to or superior to those of the conventional type. Color stability after staining depended on resin composition, with Beautifil Bulk Restorative showing more intense staining.

YouTube has emerged as a popular platform for accessing educational content. However, its effectiveness has been a topic of debate in dental education. This study aimed to analyze the content and quality of YouTube videos focusing on Class II resin composite restorations. The first 100 videos of Class II resin composite information on YouTube were evaluated. The overall quality of the videos was assessed using the video information and quality index (VIQI) and Content Score based on Class II resin composite criteria. Videos with a score of less than the mean were recognized as low-content. No significant differences were observed between high- and low-content videos when the number of views, likes, duration, days since upload, viewing rate, and interaction index were investigated (p>0.05). The number of subscribers revealed a marginally significant difference (p=0.053). The high-content videos demonstrated higher mean values compared to the low-content videos in flow (4.6 vs. 3.8; p=0.0004), accuracy (4.3 vs. 3.3; p<0.0001), value (3.7 vs. 2.9; p=0.002), and precision (4.8 vs. 4.2; p=0.0002). The overall VIQI score was significantly higher (p<0.0001) in high-content videos (Mean 17.4; SD 1.5) compared to the low-content videos (Mean 14.2; SD 2.2). When the Content Score was assessed, high-content videos (Mean 9.9; SD 1.3) revealed a higher score (p<0.0001) than low-content-videos (Mean 4.2; SD 2.3). Most YouTube videos showcasing Class II resin composites serve as effective teaching tools. However, a significant number of videos with low content exist. Therefore, dental students should exercise caution when utilizing YouTube videos for learning purposes.

This study evaluated the influence of six resin composite coating agents on color stability and surface roughness after toothbrushing abrasion. Discs (Ø6 mm x 2 mm) of nanofilled resin composite (Filtek Z350XT) were prepared for application of coating agents (n=10): control (absence), two surface sealants (PermaSeal and BisCover LV), two adhesive systems (Scotchbond Multi-Purpose Adhesive/3M Oral Care and Single Bond Universal), and two modeling liquids (Modeling Resin and Composite Wetting Resin). CIELab*, WID, and color change (ΔEab, ΔE00, and ΔWID) were analyzed at baseline, after finishing and polishing, after application of coating agents, after coffee staining (simulating 30 days and one year of staining), and after toothbrushing abrasion. Roughness evaluations (Ra) were performed at the initial time point, after finishing and polishing, after application of coating agents, and after toothbrushing abrasion. Surface micromorphology was evaluated (2,000×) before and after toothbrushing abrasion. Generalized linear mixed models or Kruskal-Wallis and Dunn tests (α=0.05) showed that L* decreased significantly (p<0.0001) and a* increased significantly in all the groups after staining (p<0.0001). After toothbrushing, Modeling Resin showed higher ΔEab and ΔE00 than the control, Scotchbond Multi-Purpose Adhesive, Composite Wetting Resin, PermaSeal, or BisCover LV (p<0.0001). There was a significant increase in roughness for Composite Wetting Resin, Modeling Resin, and PermaSeal after application of the agents (p<0.05), but a significant decrease for BisCover LV (p<0.05), which achieved high surface smoothness. After abrasive wear, BisCover LV showed the lowest roughness values among all agents. Composite Wetting Resin and Modeling Resin showed higher roughness than the other groups (p<0.05), and surface irregularities. In conclusion, the coating agents did not prevent coffee staining, and they also led to increased surface roughness, with only BisCover LV providing greater surface smoothness after toothbrush abrasion.

Objectives: This case report describes the clinical protocols for the removal of crowns, tooth extraction, immediate implant placement, and cementation of new crowns, all performed under total or partial isolation with a dental dam.

Clinical considerations: The patient's chief complaint was dissatisfaction with her smile. Radiographic and clinical evaluations led to the recommendation to replace the porcelain-fused-to-metal crowns on the maxillary central and lateral incisors with all-ceramic crowns. Considering the patient's wide smile, ceramic veneer restorations were also recommended for the maxillary canines and first premolars. An immediate implant placement was advised to replace the fractured maxillary right central incisor.

Conclusions: Well-planned dental care including crown removal, tooth extraction, immediate implant placement, and cementation of new restorations can be successfully executed under isolation using a dental dam. The isolation improves access, visibility, and hygiene by preventing cross-contamination during the cementation procedure. The final outcome fulfilled the patient's esthetic demands.