In general, patients’ opinions on reaching ideal esthetics while restoring dental tissues is one of the most important part of the oral treatment. Unfortunately, discoloration of dental materials may occur due to intrinsic and extrinsic factors. The aim of the study was to evaluate the color stability of frequently used dental resin materials and determine the mechanism of their discoloration. The study used various characterization techniques (optical microscopy, Fourier-transform infrared spectroscopy, low-temperature N₂ adsorption, diffuse reflectance spectroscopy, and luminescence) to understand the effect of surface defects on discoloration. The adsorption of model liquids on the surface was confirmed to be related to the increase in BET surface area. The study found that the adsorption of discolorants, such as coffee, tea, and wine, on the surface of the dental material follows the multilayer BET model. When the surface is smooth, the discoloration is usually within acceptable limits, with a maximum of ∆E = 3.3. The discoloration made by tea and demineralized water was within acceptable limits even after 7 days of exposure.

Background: Root canal preparation during endodontic treatment may be associated with various complications, including a change in the original pathway of the root canal lumen. The aim of our study was to determine whether files of similar sizes that use various movement kinematics (rotary, reciprocal, adaptive motion) cause root canal transportation, and whether the differences between such systems are statistically significant. Methods: The degree of root canal transportation (DT) was calculated with the use of computed tomography scans for 3 groups of teeth (for each group: n = 20) in which the root canals were prepared using either rotary (ProTaper Next—PTN), reciprocal (WaveOne Gold—WOG), or adaptive movement (Twisted Files—TF) instruments. Results: For rotary ProTaper Next instruments, the mean value of the DT index was 0.0795 (SD = 0.0179) for 3 mm from the apex, 0.09 (SD = 0.0262) for 6 mm from the apex, and 0.106 (SD = 0.0221) for 9 mm from the apex. For reciprocal WaveOne Gold Primary instruments, the mean value of the DT index was 0.0355 (SD = 0.015) for 3 mm from the apex, 0.061 (SD = 0.02) for 6 mm from the apex, and 0.08 (SD = 0.25) for 9 mm from the apex. For Twisted Files, the mean value of the DT index was 0.05 (SD = 0.03) for 3 mm from the apex, 0.092 (SD = 0.17) for 6 mm from the apex, and 0.08 (SD = 0.02) for 9 mm from the apex. Conclusions: The use of PTN, WOG, and TF files resulted in root canal transportation to a different degree. The use of rotary PTN files produced the most transported preparation, whereas the use of WOG files produced the conservative root canal preparation that allowed the retention of the original shape of the root canal.

(1) Background: Apical extrusion of debris is an example of a complication that may arise during root canal treatment, and it has been proven to be an unavoidable occurrence during endodontic treatment by numerous authors. Even though it may not hinder the long-term outcome of treatment, it may lead directly to increased levels of postoperative pain and, therefore, lower levels of patient acceptance and satisfaction. The aim of the study was to assess the weight of apically extruded debris during root canal preparation with instruments that use different movement kinematics (rotary, reciprocating, and adaptive motion); (2) Methods: The study was performed using the Myers and Montgomery model. Sixty human premolar teeth were inserted into preweighed Eppendorf tubes and randomly classified into three groups. After manual glide-path preparation, teeth in each group were instrumented to working length set 1 mm short of the anatomical apex using the standard sequence provided by the manufacturers (for Group 1: ProTaper Next X1 & X2; for Group 2: WaveOne Gold Primary, for Group 3: Twisted Files SM1-SM3). Root canals were irrigated with 1 mL of 0.9% NaCl solution between each file insertion. The tubes with collected debris were stored in an incubator at 70 °C for 5 days in order to evaporate the liquid component. Measurement of the weight of extruded debris was performed by subtracting the preinstrumentation from the postinstrumentation weight of the tubes. The results were analyzed with Kruskal–Wallis ANOVA, with significance level set at 0.05; (3) Results: The weight of extruded debris was 0.337 mg (SD = 0.148) for Group 1, 0.305 mg (SD = 0.201) for Group 2, and 0.348 mg (SD = 0.135) for Group 3. (4) Conclusions: Engine-driven root canal preparation with the use of instruments ProTaper Next, WaveOne Gold and Twisted Files that use different movement kinematics (rotary, reciprocating, and adaptive motion) was associated with apical extrusion of debris to a similar extent.

(1) Background: The aim of the paper is to determine how selected staining liquids affect color stability and reflectance of six composite and compomer dental materials. (2) Methods: Six dental materials were chosen for this study: G-aenial (GC), Filtek Z550 (3M), Herculite XRV Ultra (Kerr), Compoglass (Ivoclar Vivadent), Dyract Extra (Dentsply), and Dyract Flow (Dentsply). Ten staining liquids were used (distilled water, tea, tea with sugar, coffee, coffee with sugar, Coca-Cola^®, orange and currant juices, soy sauce, and wine). Staining was carried out at 37 °C. The measurements of the color difference (ΔE) and the color parameters were carried out on a Konica Minolta CM5 spetrocolorimeter at different staining times (1, 2, 4, 8, 24, 48, 72, and 168 h). The resulting color change of the dental materials upon staining is presented as plots of ΔE, diffuse-reflection spectra, and Maxwell’s triangle. (3) Results: Significant changes in lightness (ΔL) along with changes in the total color were observed for most materials. Color change was more pronounced in compomers than in composites. (4) Conclusions: Most materials change their color from light cream to light-brown and reddish after exposure to selected staining liquids.

(1) Background: Root canal preparation constitutes an important factor for success in endodontics. However, various complications may occur during this stage. The aim of this study was to compare the incidence of cracks within radicular dentin after instrumentation with ProTaper Next (PTN), WaveOne Gold (WOG), and Twisted Files (TF), which utilize different kinematics. (2) Methods: Eighty single-rooted teeth were classified into four groups (n = 20). Three groups were instrumented using PTN (X1, X2), WOG (Primary), and TF (SM1–3). The non-instrumented group constituted the control group. Post-preparation, the roots were sectioned 3, 6, and 9 mm from the apex using a low-speed saw (Southbay Technology Inc., San Clemente, CA, USA). The specimens were viewed through a microscope at x25 magnification (Leica M320, Wetzlar, Germany), and their surface was assessed tactilely to determine the presence of the crack. (3) Results: Partial cracks within radicular dentine were observed in all study groups (PTN: n = 4/20%, WOG: n = 3/15%, TF: n = 4/20%); no cracks were observed in the control group. No significant differences were observed among experimental groups. OR values for the incidence of cracks were: OR = 11.182 for PTN, OR = 8.2 for WOG, and OR = 8.2 for TF. (4) Conclusions: Instrumentation with PTN, WOG, and TF may result in dentinal cracks formation.

Background: Resin-based dental composites are the most widely placed direct restorative materials globally. Yet, their organic matrix and complex filler system render them a potential source of biologically active compounds. Residual monomers, including Bisphenol A-glycidyl dimethacrylate (Bis-GMA), triethylene glycol dimethacrylate (TEGDMA), 2-hydroxyethyl methacrylate (HEMA), and urethane dimethacrylate (UDMA), are released into the oral environment through incomplete polymerization, material degradation, and wear, and may subsequently reach systemic circulation. Composite matrix breakdown additionally generates micro- and nanoplastic particles (MNPs), representing a distinct emerging exposure pathway. This review synthesizes clinical and translational evidence on the oral-systemic toxicological implications of resin-based composite materials, with emphasis on biomonitoring data, mechanistic pathways, and relevant risk signals. Methods: A structured search was conducted across PubMed/MEDLINE, Embase, Scopus, and Web of Science for studies published between January 1990 and September 2025. Eligible studies reported biomonitoring outcomes (saliva, blood, urine, breast milk, cord blood, or placenta), toxicokinetic profiles, or systemic and generalized hypersensitivity reactions attributable to resin-based restorative materials. Studies on dental amalgam and non-dental polymer exposures were excluded. Data were synthesized narratively in accordance with SANRA principles. Results: Released monomers exert concentration-dependent cytotoxic, genotoxic, and immunomodulatory effects, primarily through glutathione depletion, reactive oxygen species generation, and apoptosis induction. Local adverse effects, including gingival inflammation, pulp cytotoxicity, and allergic contact stomatitis, are well-documented in vitro and in clinical case reports. Systemically, BPA and its derivatives have been detected in saliva, urine, blood, breast milk, cord blood, and placenta following dental procedures, raising concerns regarding endocrine-disrupting potential, particularly in children and pregnant women. Dental personnel constitute a distinct occupational risk group through dermal monomer exposure. Composite resins also release MNPs through wear and degradation, with preliminary data suggesting inflammatory and genotoxic potential, though clinical significance remains to be established. Conclusion: Resin composites pose a measurable, if generally low-level, toxicological risk through monomer elution and, increasingly, MNP release. Adequate operative technique substantially reduces patient exposure. Vulnerable populations, including children, pregnant women, and dental personnel, warrant particular attention. Standardized biomonitoring protocols, updated regulatory thresholds, and dedicated in vivo studies are needed to characterize the long-term oral-systemic health implications of these ubiquitous materials.