PurposeThis in vitro study aimed to assess the penetration of root canal sealer (RCS) into dentinal tubules after the application of an intracanal medicament in hydrogel form (BA) and the effect of irrigation activation methods for its removal using a stereomicroscope.Materials and MethodsA total of 135 mandibular single-rooted premolars with round morphology were used. Root canals were instrumented and allocated into three main groups according to intracanal medicament: BA, calcium hydroxide (CH), and negative control with no medicament (NC). Subgroups were determined: sonic, passive ultrasonic activation (PUI), and conventional needle irrigation (needle). Medicaments were applied and removed using irrigation activation methods. Samples were filled using epoxy resin sealer/gutta-percha, sectioned into apical, middle, and coronal parts in 1-mm thickness, and stereomicroscopic images were obtained. Maximum root canal sealer penetration and penetration area were analyzed using ImageJ. One-way ANOVA and intra-class correlation were used for statistical analysis.ResultsSonic and PUI presented higher RCS penetration in all root thirds. After using the BA in the middle and coronal thirds, irrigation activation showed better results (p<0.05). After using the BA, root canal sealer penetration into dentinal tubules was higher than that of CH in all thirds (p<0.05).ConclusionFollowing the use of the BA, greater RCS was observed compared with CH. These findings suggest that the BA did not adversely affect RCS penetration. The hydrogel may represent a promising vehicle material for intracanal medicament formulations. Sonic and PUI showed a similar effect for medicament removal. However, since residual intracanal medicament was not directly quantified, no conclusions regarding actual removal efficiency can be drawn.
PurposeThe aim of this study is to evaluate in vitro the morphological and physicochemical effects of an experimental epigallocatechin-3-gallate (EGCG) gel and its combinationwith sodium fluoride (NaF) on the progression of dentin erosion.Materials and MethodsInitial lesions were induced in bovine dentin samples (n=10/group) and divided into: Control (gel without active ingredients), NaF (1.23% NaF), EGCG (10% EGCG), and EGCG+NaF (10% EGCG + 1.23% NaF). Half of the sample was protected and the other half treated and subjected to erosive/abrasive challenges (0.3% citric acid, pH=2.6 and simulated brushing). Volume loss (VL) and surface roughness (Ra) were evaluated by 3D laser confocal microscopy. Dentin composition was analyzed by Raman spectroscopy, considering mineral/matrix ratio (MMR), collagen organization, and crystallinity.ResultsThe EGCG+NaF group presented the lowest VL values (p<0.05). The Control group had the highest MMR values, while the EGCG+NaF group presented the lowest (p<0.05). For the Amide I/III ratio, the Control group had the lowest values and the EGCG+NaF group the highest (p<0.05). No statistically significant differences among the groups regarding the crystallographic order (p= 0.668).ConclusionThe combination of EGCG and NaF demonstrates the ability to mitigate volume loss under erosive-abrasive challenges, preserve structural integrity, and enhance collagen cross-linking within the demineralized organic matrix of dentin.
Purpose:Edentulism compromises oral function and quality of life. The All-on-4 concept offers a fixed alternative to conventional dentures under immediate loading. However, evidence on outcomes in anatomically challenging arches, particularly with dynamic navigation, remains limited. This study reports early clinical and radiographic outcomes, and the feasibility, of immediate-loading all-on-4 in a real-world setting using an anatomy-driven allocation strategy with freehand and navigation workflows. Materials and Methods:This retrospective cohort included consecutive patients treated between November 2023 and February 2025. Dynamic navigation was selectively applied in unfavorable arches; freehand surgery was used otherwise. Four implants per arch supported screw-retained provisional prostheses delivered within 24-36 hours. Primary outcomes were implant and arch-level survival and marginal bone level (MBL) change. Secondary outcomes included complications and provisional prosthesis survival. Results:Twenty-two patients (23 arches; 92 implants) were analyzed: 13 arches freehand and 10 navigation. Median follow-up was 5.11 months. Five implants failed (5.43%), all in the maxilla, affecting four arches (one navigation, three freehand). Implant survival was 94.23% (freehand) and 95.00% (navigation). MBL change was negligible, consistent with early remodeling and measurement variability. Biological complications occurred in 8 implants (8.70%), and two provisional fractures were repaired; 22 of 23 prostheses remained functional (95.65%). Conclusion:Immediate-loading All-on-4 with selective navigation achieved high short-term implant and prosthesis survival and minimal MBL variation. These findings support the feasibility of navigation in demanding arches in routine practice, warranting confirmation in prospective studies with longer follow-up.
Purpose:The aim of this study is to compare trueness and precision of dental models from three LCD 3D printers with different horizontal resolutions (2K, 4K, 8K) and to evaluate their clinical suitability for orthodontic use. Materials and Methods:Thirty models were printed using Creality Halot One (2K), Phrozen Mighty 4K, and Phrozen Mighty 8K printers, with ten models each using manufacturer-recommended resins. Master digital models from intraoral scans were compared to re-scanned printed models through surface superimposition using Geomagic Control X software. Trueness and precision were evaluated by point deviation and Root-Mean-Square (RMS) analysis, with differences assessed by one-way ANOVA (p = 0.05). Results:Mean RMS values for 2K, 4K, and 8K printers were 0.266 ± 0.015 mm, 0.223 ± 0.017 mm, and 0.121 ± 0.012 mm, respectively (p < 0.001). The 8K printer showed highest trueness and precision, with deviations mainly in occlusal and gingival regions. The 0.25 mm error limit was within acceptable range for 4K and 8K models, while 2K models exceeded this value (p < 0.05). Conclusion:Printer resolution significantly affects dimensional accuracy. The 8K LCD printer demonstrated superior accuracy and reproducibility, proving reliable for orthodontic models and clear aligners.
Purpose:The aim is to evaluate and compare the effects of single versus repeated applications of potassium iodide (KI) on SDF-induced discoloration in primary canines. Materials and Methods:Thirty-six extracted human primary canines with dentinal caries were randomly allocated into three groups: Group I received 38% SDF alone; Group II received SDF followed by a single KI application; and Group III received SDF followed by immediately application after SDF and repeated on days 1, 3, and 5. Color change (∆E) was assessed on Days 1, 14, and 30 using a spectrophotometer based on the CIE Lab* system. Statistical analysis included One-Way ANOVA with Tukey post hoc tests for between-group comparisons, and Repeated Measures ANOVA with Bonferroni adjustment for within-group comparisons. Results:All groups showed significant differences in ΔE values at each time point, except between the single and repeated KI groups on Day 1. The Group I exhibited the highest ΔE values throughout the study, indicating the greatest discoloration, while Group III resulted in the lowest values. Over time, a progressive increase in discoloration was observed in Groups II, whereas partial color stability was maintained in Group III. Conclusion:Repeated application of KI after SDF treatment can result in a higher reduction in tooth discoloration compared to a single-application. This protocol may enhance the clinical acceptability of SDF, especially for visible anterior teeth in pediatric patients.
