The aim of this in vitro study is to compare the color stability and surface roughness of conventional and self-blending resin composites before and after staining and aging. Three conventional composites (Filtek Z350, IPS Empress Direct, and Estalite Palfique LX5) and one self-blending (Omnichroma) resin composite were used in this study. Sixty discs were prepared and polymerized in a metal mold (n = 15 per group). Samples were then finished and polished by Layan discs. Color testing and roughness testing were measured as a baseline (T0) by a spectrophotometer and profilometry. Samples were then stained with tea for 24 h, water aged for 30 days, and then a second reading (T1) was performed. Finishing and polishing were performed again, and a third reading (T2) was collected. All groups showed significant decrease in all color parameters (L*, a*, and b*); however, after polishing, all groups showed color enhancements matching pre-experiment baseline colors in all color parameters (L*, a*, and b*), except for Estelite Palfique LX5, which showed a significant difference in L relative to the baseline. Furthermore, Estalite Palfique LX5 showed increased roughness after staining compared to the baseline, unlike other groups. No significant differences in color stability were found between self-blending composites and other composite materials. Accelerated aging and staining had minimal effects on the surface roughness of self-blending composite.

Contamination of zirconia restorations before cementation can impair the resin–zirconia bonding durability. The objective of this study was to evaluate the effect of human saliva or blood decontamination with 10-methacryloyloxydecyl dihydrogen phosphate (10-MDP)-containing cleaner on the resin–zirconia shear bond strength (SBS). Methods: A total of 220 zirconia specimens were prepared and air-abraded and randomly distributed into 11 groups (n = 20 per group). Except for the control group (no contamination), zirconia specimens were contaminated with either human saliva (five groups) or blood (five groups), and then subjected to one of five cleaning methods: water rinsing, 38% phosphoric acid etchant (Pulpdent Corp., Watertown, MA, USA), 70% isopropanol alcohol (Avalon Pharma, Riyadh, Saudi Arabia), Ivoclean (Ivoclar Vivadent, Schaan, Lichtenstein) and Katana Cleaner (Kuraray Noritake, Tokyo, Japan). The resin–zirconia SBS was tested at 24 h and after thermocycling (10 k cycles). Three-way ANOVA followed by Tukey’s multiple comparisons test were utilized to analyze the SBS data. Failure modes were evaluated using a scanning electron microscope. Results: Both blood and saliva significantly affected resin–zirconia SBS as contaminants. After thermocycling, there was no statistically significant difference between SBS obtained after decontamination with the Katana Cleaner (blood, 6.026 ± 2.805 MPa; saliva, 5.206 ± 2.212 MPa) or Ivoclean (blood, 7.08 ± 3.309 MPa; saliva, 6.297 ± 3.083 MPa), and the control group (no contamination, 7.479 ± 3.64 MPa). Adhesive and mixed failures were the most frequent among the tested groups. Conclusion: Both 10-MDP-containing cleaner (Katana Cleaner) and zirconium oxide-containing cleaner (Ivoclean) could eliminate the negative effect of saliva and blood contamination on resin–zirconia SBS.

Objective: The objective of this review was to evaluate the effect of non-thermal atmospheric plasma (NTAP) on adhesives resin–dentin micro-tensile bond strength (μTBS) in previously published studies. Methods: Electronic search was conducted using the Medline, Cochrane library, and Scopus databases. The included studies were laboratory studies that investigated the effect of NTAP on adhesives μTBS to coronal dentin. Studies that evaluated the effect of NTAP on bond strength to indirect substrates, enamel or root dentin, were excluded. The methodological quality of included studies was assessed. Results: Thirteen studies were included in this systematic review. All the included studies were considered to have a medium risk of bias. NTAP significantly improved μTBS at 24 h or after short-term aging in five studies (38.5%) and both immediate and after long-term aging in 5 studies (38.5%). In two studies (15.4%), NTAP resulted in a short-term material-dependent effect that was not stable after long-term aging. Interestingly, in one study (7.7%), NTAP had a positive effect only in the etch-and-rinse (ER) mode after long-term aging. Conclusion: Within the limitations of this systematic review, NTAP application could enhance resin–dentin μTBS of ER adhesives or universal adhesives (UAs) applied in the ER mode. In the ER mode, the rewetting step after NTAP seems to be unnecessary. Because of the limited information currently available in the literature, further studies are required to evaluate the effect of the NTAP application on self-etch (SE) adhesives or UAs applied in the SE mode.

(1) Background: A newer class of flowable bulk-fill resin-based composite (BF–RBC) materials requires no capping layer (Palfique Bulk flow, PaBF, Tokuyama Dental, Tokyo, Japan). The objective of this study was to assess the flexural strength, microhardness, surface roughness, and color stability of PaBF compared to two BF-RBCs with different consistencies. (2) Methods: PaBF, SDR Flow composite (SDRf: Charlotte, NC, USA) and One Bulk fill (OneBF: 3M, St. Paul, MN, USA) were evaluated for flexural strength with a universal testing machine, surface microhardness using a pyramidal Vickers indenter, and surface roughness using a high-resolution three-dimensional non-contact optical profiler, a and clinical spectrophotometer to measure the color stability of each BF–RBC material. (3) Results: OneBF presented statistically higher flexural strength and microhardness than PaBF or SDRf. Both PaBF and SDRf presented significantly less surface roughness compared with OneBF. Water storage significantly reduced the flexural strength and increased the surface roughness of all tested materials. Only SDRf showed significant color change after water storage. (4) Conclusions: The physico-mechanical properties of PaBF do not support its use without a capping layer in the stress bearing areas. PaBF showed less flexural strength compared with OneBF. Therefore, its use should be limited to a small restoration with minimal occlusal stresses.

Cention N (CN; Ivoclar Vivadent, Schaan, Liechtenstein), advertised as an alkasite, is a bioactive bulk-fill resin-based composite (BF-RBC) with alkaline fillers. This study evaluated the resin-dentin micro-tensile bond strength (μTBS) and cytotoxicity of CN. Methods: Flat dentin surfaces were obtained, bonded with a universal adhesive, and randomly distributed into two groups. CN (group I) and a flowable BF-RBC, namely, Tetric N-Flow Bulk Fill, Ivoclar Vivadent, Schaan, Liechtenstein (group II), were used. After thermocycling, bonded samples were sectioned into micro-beams for μTBS evaluation. Resin-based composite (RBC) discs with a thickness of 2 and 4 mm were tested on human gingival fibroblast cells (HGFCs). Cytotoxicity was assessed by cell viability and growth using AlamarBlue^® (Biosource, Camarillo, CA, USA) over a seven-day period. Independent t-test was utilized to statistically analyze μTBS data, while one- and two-way analysis of variance (ANOVA) and Tukey’s post-hoc tests were utilized to analyze the cell viability data. Results: There was no statistically significant difference (p > 0.05) in the μTBS between the flowable BF-RBC and CN. For both materials, the HGFCs were viable, with constant growing over the seven-day period. Conclusion: CN provided a resin-dentin μTBS that was comparable to that provided by the flowable BF-RBC. Both materials showed acceptable cytotoxicity over the seven-day period at a thickness of both 2 and 4 mm.

This systematic review aimed to compare the efficacy of herbal agents with ethylene diamine tetraacetic acid (EDTA) in removing the smear layer during root canal instrumentation. The research question in the present study was to assess: “Is there a significant difference in reducing smear layer comparing EDTA and herbal agents?” Electronic databases (PubMed, Scopus, and Web of Science) were searched from their start dates to April 2022 using strict inclusion and exclusion criteria, and reviewed following PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) 2020 guidelines. Only in vitro studies comparing herbal agents with EDTA were included in the current systematic review. Two reviewers independently assessed the included articles. A total of 625 articles were obtained from an electronic database. Eighteen papers were included for review of the full text, out of which, ten papers were excluded because they did not meet the inclusion criteria. Finally, eight articles were included in the systematic review. The present systematic review considered only in vitro studies; hence, the result cannot be completely translated to strict clinical conditions. The results of the present systematic review have shown that quixabeira, morindacitrifolia, oregano extract, and neem show better smear layer removal compared to other herbal agents, whereas they showed reduced smear layer removal when compared with EDTA. Although, it was seen that most of the included studies did not report a high quality of evidence. Hence, the present systematic review concludes that herbal agents have reported to show inferior smear layer removal when compared to EDTA. Thus, as far as herbal based alternatives are concerned, there is no highest level of evidence to state its real benefit when used as a chelating root canal irrigant.