Background: This study aimed to evaluate the color-matching and light transmission properties of a newly developed aesthetic flowable resin composite, OCFB-001. Methods: Rubber molds containing cylindrical cavities were filled with Estelite Sigma Quick, and 40 resin composite (CR) molds with simulated Class I cavities were prepared in shades A1, A2, A3, and A4, resulting in a total of 160 samples. Following bonding procedures, four different flowable resin composites (n = 10) were introduced into the cavities. The color difference (ΔE₀₀) was calculated using two methods. A two-way analysis of variance was performed, and the interaction was significant, so a post hoc analysis was performed for each shade using Bonferroni’s correction. The morphology of the filler in each material was observed via scanning electron microscopy (SEM). Results: In the A1 shade, OCFB-001 demonstrated color differences comparable to those of other materials. However, in the A2, A3, and A4 shades, OCFB-001 exhibited significantly lower color differences (ΔE₀₀) than the other materials, with a more consistent distribution. SEM analysis revealed that the OCFB-001 structure resembled that of Estelite Bulk Fill Flowable. Conclusions: OCFB-001 showed excellent shade matching in the A2, A3, and A4 ranges and good matching in the A1 shade, on par with existing universal-shade flowable bulk-fill resin composites.

Tooth bleaching is a widely used esthetic treatment; however, bleaching agents can temporarily alter the surface morphology of enamel, increasing surface roughness and porosity, which may lead to increased susceptibility to discoloration. This in vitro study investigated the effectiveness of fluoride varnish in preventing immediate discoloration of bovine incisors after bleaching. Specimens were bleached with 35% hydrogen peroxide and treated with either Clinpro White Varnish (CW) or Enamelast Fluoride Varnish (EN), whereas control specimens received no treatment after bleaching. The samples were immersed in coffee for 24 h, and the color difference (ΔE₀₀) was calculated using the CIEDE2000 formula. The surface morphology of enamel was examined using SEM. The fluoride varnish groups showed significantly lower color difference values than the control group (p < 0.05), with ΔE₀₀ reduced by approximately two-thirds in both the CW and EN groups. SEM observations showed that the enamel surfaces in the varnish-treated groups exhibited reduced surface irregularities compared to the untreated group, suggesting remineralization. These results suggest that the immediate application of fluoride varnish after bleaching can effectively reduce short-term discoloration by providing physical protection and promoting remineralization. Fluoride varnish may serve as a simple and effective strategy to maintain whitening outcomes and minimize early discoloration.

This in vitro study aimed to investigate whether color differences in the stained cavity floor simulating recurrent caries can be detected using various restored resin composites. Artificial teeth were made with conventional resin composite (Estellite Sigma Quick A3; ET), and class V cavities were prepared. To simulate the color of caries, a dot was marked in the center of the cavity floor using four different magic pens. The cavities were filled with ET and two universal shade resin composites (UC, Omnichroma; OMI, Essentia Universal; ESS). For photographic analysis, a standard correction color chart was used. The color difference (ΔE₀₀) between (i) the lab value at the center of the cavity and (ii) the average lab value at 1 mm mesial and distal to the center of the cavity was calculated. The data were statistically analyzed using two-way ANOVA (p < 0.05). For visual analysis, 25 dentists were asked to complete a questionnaire to determine whether the color differences were noticeable. In the photographic analysis, UC showed larger ΔE₀₀ values than ET in all colors. Visual analysis revealed higher detection rates for UC than ET. Universal shade resin composite tends to reflect the color of the cavity more effectively than conventional resin composite.

Tooth bleaching improves dental esthetics but may cause color mismatch with existing resin composite restorations and complicate restorative treatment planning because tooth color may change during the post-bleaching stabilization period, sometimes requiring delayed restoration placement or replacement of existing restorations. Universal shade resin composite (UC) has been introduced to simplify shade selection; however, its ability to adapt to dynamic tooth color changes associated with bleaching has not been sufficiently documented. A 61-year-old male patient underwent tooth bleaching for esthetic improvement. One year later, secondary caries was detected on tooth #22 and restored using a UC. The restoration was placed prior to additional bleaching procedures. Clinical follow-up indicated that the UC restoration appeared to maintain shade adaptation after bleaching. Furthermore, at the two-year follow-up, generalized tooth discoloration was observed; however, the restoration remained harmonized with the surrounding tooth structure. Subsequent additional bleaching resulted in further lightening of the tooth structure while shade harmony with the restoration was preserved. Favorable shade adaptation was maintained throughout the three-year follow-up. This case suggests that a UC restoration placed before bleaching appeared to maintain shade compatibility over long-term follow-up, despite bleaching-induced color improvement and subsequent intrinsic and extrinsic discoloration.

Self-adhering flowable composites (SAFCs) were developed to simplify restorative procedures by eliminating separate adhesive steps; however, their bonding performance, mechanical properties, and biological properties remain controversial. This study evaluated a newly developed SAFC (SA-100R) compared with three commercial SAFCs (Fusio Liquid Dentin, Constic, and Vertise Flow) and a conventional composite (Clearfil AP-X used with a two-step self-etch adhesive). Microtensile bond strength (μTBS) to dentin, failure modes, Knoop microhardness, resin–dentin interfacial morphology (SEM), elemental composition (EDX), and cytocompatibility (CCK-8, LIVE/DEAD staining) were assessed. The conventional composite system exhibited significantly higher µTBS than all SAFCs (p < 0.05). Among SAFCs, SA-100R showed the highest bond strength and no pre-testing failures. SEM revealed abundant resin tag formation only in the conventional system, while all SAFCs showed interfacial gaps, with SA-100R exhibiting the least pronounced gaps. SA-100R showed no significant cytotoxic effects across all tested concentrations. Within the limitations of this short-term in vitro investigation, SA-100R demonstrated improved bonding performance and favorable biocompatibility compared with existing SAFCs, suggesting its potential as a simplified restorative material. However, the conventional adhesive/composite system remains the reference standard for dentin bond strength, and long-term clinical performance remains to be established through further studies.

Background: The association between oral health and gastrointestinal (GI) cancers has been primarily investigated within a periodontitis-centered framework. However, the potential contribution of cumulative oral disease burden, including dental caries and apical pathology, remains insufficiently explored. The Decayed, Missing, and Filled Teeth (DMFT) index reflects lifetime exposure to oral microbial dysbiosis and chronic inflammation. Methods: This retrospective exploratory study included patients with GI cancers referred for perioperative oral screening and management at a tertiary care center between 2015 and 2025. Oral health was evaluated using the DMFT index, periodontal probing depth, and radiographically diagnosed apical periodontitis. Age-stratified DMFT and periodontal parameters were compared with national reference data, while apical periodontitis prevalence was descriptively assessed. Results: Patients with GI cancers demonstrated higher DMFT values than national averages across most adult age groups. The prevalence of periodontal pockets (≥4 mm and ≥6 mm) was also elevated. Apical periodontitis was common, affecting 46.3% of patients, with some age groups exceeding 50%. Overall, these findings indicate oral disease clustering with coexisting chronic oral conditions. Conclusions: Patients with GI cancers exhibit substantial oral disease burden, including increased caries experience, periodontal pathology, and apical lesions. These findings suggest that the oral–gastrointestinal cancer relationship may extend beyond a periodontitis-centered paradigm, and that cumulative oral disease burden—including cariogenic processes—may represent an underrecognized component of this axis. The DMFT index may serve as a surrogate marker of lifelong oral inflammatory exposure. While causal relationships cannot be established, this study provides a basis for future mechanistic and longitudinal investigations.