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Analysis of Orthodontic Treatment Requirements and Their Influence on Quality of Life and Self-Esteem Among Adults
(Galenos, 2026) Zeynep, Aslihan; Öz, Abdullah Alper; Özaydın, Özge
Objective: To evaluate the the association of orthodontic treatment need on oral health-related quality of life (OHRQoL) and self-esteem in adult patients seeking orthodontic care. Methods: A total of 110 adults were recruited for the study. Orthodontic treatment need was evaluated using the index of complexity, outcome and need (ICON). Patients with a score of 43 and above were classified as Group 1; those with a score below 43 were classified as Group 2. Oral health-related quality of life was evaluated using the Oral Health Impact Profile-14 (OHIP-14), and self-esteem was assessed using the rosenberg self-esteem scale (RSES). Statistical evaluation involved Spearman's rank correlation, Mann-Whitney U tests, and independent samples t-tests. Results:The mean OHIP-14 score was higher in Group 1 (12.63 +/- 7.46) than in Group 2 (10.61 +/- 7.46). However, this difference was not statistically significant (p=0.176). Mean RSES scores did not differ significantly between the groups (p=0.741). A slight but meaningful positive correlation emerged between ICON and OHIP-14 scores, indicating that as orthodontic treatment need increased, OHRQoL tended to decrease. No significant correlation was observed between ICON and RSES. Additionally, gender was not significantly associated with either OHIP-14 or RSES scores. Conclusion:The analysis revealed that increased need for orthodontic treatment is associated with a slight worsening of OHRQoL but does not significantly affect self-esteem in adult subjects.
Effect of Solvent Use on Dentinal Integrity and Filling Removal During Endodontic Retreatment: A Micro-Computed Tomography Study
(2026) Zümrütel, Pelin; Haznedaroğlu, Faruk; Keleş, Ali; Basmacı, Gülsüm Kutlu
Introduction: This study evaluated, using micro-computed tomography (micro-CT), whether solvent use during endodontic retreatment influences dentinal defect formation and the removal of filling material compared with mechanical retreatment alone. Materials and methods: Twenty extracted human mandibular molars were prepared and obturated using standardized protocols and randomly allocated to solvent-assisted retreatment or retreatment without solvent (n=10 per group). Micro-CT scans were obtained before treatment, after obturation, and after retreatment at a voxel size of 13.68 μm. Dentinal defects were assessed using axial images, and residual filling-material volume was measured three-dimensionally in the apical, middle, and coronal thirds. Between-group comparisons were performed using the Welch independent-samples t-test or Mann-Whitney U test, as appropriate. Within-group comparisons were performed using the Friedman test. Results: No dentinal defects were detected in any specimen (0/20). However, the exact 95% confidence interval indicated that a low-incidence effect could not be excluded. Residual filling material was detected in all canals after retreatment. No significant differences were observed between the solvent-assisted and non-solvent groups in residual filling-material volume at any canal third after adjustment for multiple comparisons (all adjusted P>0.05). Conclusions: Under the conditions of this in vitro study, solvent use did not significantly improve filling-material removal compared with mechanical retreatment alone. No dentinal defects were detected in either group; however, the exploratory nature and limited sample size of the dentinal-defect analysis preclude excluding a low-incidence effect.
Barodontalgia and Flight Safety: A Critical Narrative Review of Pressure Physiology, Acute Pain, and Human Factors
(İstanbul University Press, 2026) Gürler, Esra Bihter
Barodontalgia is dental or orofacial pain brought on by a change in barometric pressure, and it usually points to an underlying dental or maxillofacial problem rather than standing as a disease on its own. This narrative review looks at the condition through five lenses: pressure physiology, clinical presentation, epidemiology, occupational stress, and human factors relevant to flight safety. A literature search was conducted using PubMed/MEDLINE, Web of Science, Scopus, Google Scholar, and DergiPark between 22 April and 7 June 2026. One systematic review covering 4,894 aircrew members and divers reported an overall experience rate of 8.2%, with divers at 9.8% and aircrew at 5.8%. Divers may be more exposed simply because pressure changes more rapidly over a short vertical distance underwater and because descent-ascent cycles occur more often, though differences in study design across the diving and aviation literature make a direct comparison difficult. A Turkish pilot survey found that 81% of those who had experienced barodontalgia placed the pain below 2,000 ft. That is a striking figure, but it comes from self-report: it points to a plausible overlap with low-altitude, pressure-changing flight segments without actually confirming the flight phase or an operational safety effect. Bruxism, occupational stress, and barodontalgia appear together in the literature, but the association is observational and says nothing about causality. General pain research backs the idea that pain can pull attention away from a task, yet no study has measured pilot performance during an actual barodontalgia episode. Taken as a whole, the evidence makes barodontalgia a biologically credible and operationally worth-watching problem, potentially preventable in principle, even if its real performance cost has not yet been quantified
Illuminant-dependent color inconstancy and metameric behavior of anodized titanium through silicone-based gingival simulation layers of varying thickness
(Springer, 2026) Çopuroğlu, Akanay; Davut, Umur; Doğanay Özyılmaz, Özge; Özyılmaz, Özgün Yusuf
This in vitro study evaluated how gingival thickness and anodization color affect color perception of Grade V titanium discs under different light sources. Ninety-six titanium discs were anodized yellow, pink, or purple, or left non-anodized. Silicone gingival masks of 1 mm and 2 mm simulated soft tissue. A single spectral reflectance measurement was recorded for each specimen using a benchtop spectrophotometer, from which color coordinates under five standardized illuminants (D65, D50, A, F2, F11) were computationally derived. Color differences (ΔE₀₀) were calculated using the CIEDE2000 formula to evaluate color inconstancy, and metamerism was quantified using a CIEDE2000-based metamerism index (MI), the mean absolute difference between ΔE₀₀ under the test illuminants (D50, A, F2, F11) and D65. Data were analyzed with one-way ANOVA, Tukey HSD post hoc tests, and independent t-tests (α=0.05). All anodized colors at 1 mm exceeded the CIEDE2000 clinical acceptability threshold (ΔE₀₀ >1.8), with purple showing the highest inconstancy, particularly under fluorescent lighting (P<.05). Increasing thickness to 2 mm significantly reduced ΔE₀₀ across all groups (P<.05), although values remained above the acceptability threshold in every group, with purple showing the greatest relative stability under all illuminants. Metameric behavior remained imperceptible under most conditions, except for pink at 1 mm under F2. Thickness and lighting significantly affect color stability of anodized titanium, although the effect of illuminant type was color-dependent: fluorescent (F2) illumination increased color inconstancy for purple and, at 2 mm, yellow, whereas pink showed the opposite pattern, with its lowest ΔE₀₀ values occurring under F2 rather than D65 at both thicknesses. Thinner tissue intensifies color shifts, while≥2 mm thickness improves consistency. Pink performs better in thin tissue; purple shows greatest stability with thicker coverage. Metamerism was imperceptible under most conditions, except for pink at 1 mm under F2, which reached a perceptible but clinically acceptable level.
Retention and Wear Performance of Locator Attachments Under Cyclic Loading: An In Vitro Study
(2026) Dede, Merve; Bozdağ, Ergün; Dayan, Süleyman Çağatay; Ünalan, Fatma
Purpose: The objectives of the current study were to evaluate and compare the retention loss and wear rates of locater attachments made of three different materials under cyclic load. Materials and methods: Three locater attachments, including those made of titanium nitride-coated (conventional Locator), titanium carbon nitride-coated (Locator R-Tx), and zirconia (TAV Locker), were used to produce 42 specimens. Half of the samples in each group were placed straight, while the other half were positioned at the maximum recommended angulation in custom aluminum molds. Each sample was treated to 5,000 insertion-separation cycles. Retention forces were assessed after 10, 500, 1,000, 4,000, and 5,000 insertion-separation cycles. Furthermore, the wear of the attachments was assessed using the mass loss technique and scanning electron microscopy. Results: Although the mean retention values of the angle-placed attachments did not differ significantly across all cycles (p > 0.05), there was a statistically significant difference in the mean retention values of the straight-placed attachments across all cycles. titanium carbon nitride demonstrated higher retention values in each retention test cycle compared to titanium nitride-coated and zirconia locator attachments (p≤0.001). The greatest weight loss among the locator attachments was observed in the titanium carbon nitride-coated angle-placed group (-0,066), while among the nylon inserts, the titanium nitride-coated angle-placed group exhibited the most significant weight loss. (-2,727). Conclusion: The retention force of the titanium carbon nitride-coated group was statistically higher both in straight and angle-placed specimens at the beginning and end of the study compared to the other attachment groups.
Influence of Different Surface Modifications on the Reverse Torque Values of Abutment Screws: An In Vitro Study
(2026) Dede, Merve; Özyılmaz, Özgün Yusuf; Doğanay Özyılmaz, Özge; Hancı Abay, Gamze
Evidence regarding tantalum nitride (TaN)-coated gold abutment screws is lacking, and studies on diamond-like carbon (DLC)-coated and anaerobic adhesive-coated abutment screws remain limited. This study evaluated the reverse torque values (RTVs) of abutment screws with different surface modifications. Sixty abutment screws from the same implant system were divided into five groups (n = 12): gold, TaN-coated gold, titanium, DLC-coated titanium, and anaerobic adhesive-coated titanium. Abutments were tightened according to the manufacturer’s recommended torque. Specimens were then subjected to cyclic loading (50 N, 1 Hz, 480,000 cycles) in a dual-axis chewing simulator, after which RTVs were evaluated. ANOVA showed a significant difference only for the uncoated gold screw group (p < 0.05). The lowest RTVs were observed in the gold screws. Although the differences among the modified screw groups were not statistically significant, surface-treated screws demonstrated higher and more stable RTVs than their uncoated counterparts. TaN-, DLC-, and anaerobic adhesive-treated screws exhibited higher RTVs following cyclic loading, suggesting that these surface modifications may enhance screw stability and reduce the risk of abutment screw loosening.
A Comparison of the Color Stability and Surface Roughness of 2 Different Laminate Porcelains in Various Solutions
(2026) Baykal, Denizhan; Akman, Burcu; Çopuroğlu, Akanay; Topalan, Onur; Davut, Umur; Özyılmaz, Özgün Yusuf
Background: Esthetics is a primary concern in modern dentistry, and laminate veneers are commonly used for addressing discoloration and shape anomalies. Understanding the effects of various beverages on the color and surface roughness of dental ceramics is crucial for long-term clinical success. Methods: Fifty specimens were prepared from feldspathic (VITA Cerec) and leucite-reinforced ceramic blocks (IPS Empress Esthetic CAD). After standardized polishing and glazing, the specimens were immersed in 5 solutions (coffee, tea, cola, wine, and distilled water) and stored for 3 months. Color changes (ΔE) were measured with a spectrophotometer, and surface roughness (Ra) was evaluated using a profilometer at baseline, 1 week, 1 month, and 3 months. Results: IPS Empress Esthetic CAD specimens demonstrated greater color change than VITA specimens, with wine causing the most significant ΔE values in both groups. All color changes remained clinically acceptable (ΔE < 3.3). Surface roughness increased slightly over time but did not show statistically significant differences in any group. Conclusion: Both laminate porcelain materials demonstrated acceptable color stability and surface integrity after prolonged exposure to common beverages. Wine produced the highest color changes, while roughness changes were minimal and not significant.
Stress distribution in titanium and zirconia implants with full-arch prostheses: a finite element analysis
(BMC, 2026) Saz, Bahattin; Özyılmaz, Özgün Yusuf; Özyılmaz, Özge Doğanay
Objective The stress distribution and mechanical properties of materials used in dental implants are critically important for implant success and long-term stability. The aim of this study was to evaluate the stress distribution on implant, prosthetic system, and peri-implant tissues when titanium and zirconia implants are used with different framework materials using three-dimensional finite element analysis (FEA). Methods A three-dimensional edentulous maxilla model was reconstructed from computed tomography data, and twelve finite element models were subsequently developed based on this anatomy to represent different implant and framework configurations. Within the scope of the study, titanium and zirconia implants were modeled in combination with cantilevered and noncantilevered prosthesis types and Co-Cr, PEKK, and zirconium framework materials. An oblique static load of 200 N was applied at a 45° angle in the palato-buccal direction to the central fossa of the first molar on the models. The Von Mises and principal stress distributions in the implant, abutment, screw, framework, and peri-implant bone were examined. Results The highest Von Mises value was recorded in the cantilevered PEKK framework zirconia implant model (378.388 MPa). Compared with the Co-Cr and zirconium framework, the PEKK framework resulted in higher Von Mises stresses and greater prosthesis displacement. The presence of a cantilever increased stress levels in all framework materials, and stress concentrations were observed particularly in posterior abutments and peri-implant bone. Furthermore, stress values in trabecular bone were recorded above the physiological threshold level in the cantilevered PEKK framework models. Conclusions Although zirconia implants exhibited greater stress than titanium implants, they remained within safe limits. Rigid framework materials and cantilever-free designs provide more balanced biomechanical results.
Correction: Dimensional and cross-sectional compatibility of contemporary nickel-titanium files and their corresponding gutta-percha cones: A micro-computed tomography study
(2026) Şarkan, Cem; Haznedaroğlu, Faruk; Keleş, Ali
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Effect of different laser modalities and treatment methods on the surface roughness and alterations of 3D printed resins and PEEK: An in vitro study
(Elsevier, 2026) Karabağlı, İrem Çelikyürek; Çopuroğlu, Akanay; Kayahan, Zeynep Özkurt; Özyılmaz, Özgün Yusuf
Statement of problem The effects of laser irradiation, airborne-particle abrasion, and electrolytic cleaning on the surface roughness of 3-dimensionally (3D) printed resin and PEEK healing abutments remain unclear. Purpose The purpose of this in vitro study was to examine surface changes after different treatment methods were applied to the surfaces of the different 3D printed resin and PEEK materials used as custom healing abutments. Material and methods Disk-shaped specimens (3×10 mm) were fabricated from three 3D printed resins (VarseoSmile TriniQ, Saremco Print Crowntec, C&B Ceramic Resin) and PEEK (CopraPeek) (N=240). Specimens were assigned to 5 surface treatment groups: erbium-doped yttrium aluminum garnet (Er:YAG), neodymium-doped yttrium aluminum garnet (Nd:YAG), diode laser, airborne-particle abrasion, and GalvoSurge (n=48). Surface roughness (Ra) was measured at baseline (T0) and after treatment (T1). Representative specimens were examined using scanning electron microscopy (SEM). Data were analyzed using nonparametric tests (α=.05). Results Airborne-particle abrasion and Er:YAG significantly increased surface roughness in all groups (P<.05). The highest roughness was observed in the Crowntec–airborne-particle abrasion group (0.89 ±0.09 µm), and the lowest in the TriniQ–GalvoSurge group (0.09 ±0.02 µm). GalvoSurge caused no significant change in TriniQ and PEEK but increased roughness in C&B and Crowntec. Nd:YAG showed no effect in TriniQ and C&B but increased roughness in Crowntec and PEEK, while diode laser affected only Crowntec (P<.05). SEM analysis confirmed treatment-dependent surface morphology changes. Conclusions Surface treatments altered resin and PEEK surface properties. Airborne-particle abrasion and Er:YAG laser treatments resulted in the greatest increases in surface roughness, while GalvoSurge and diode laser treatments generally caused minimal or nonsignificant changes.
Assessment of Surface Roughness and Bacterial Adhesion of Occlusal Splints Fabricated with Different Layer Thicknesses, Polishing Techniques and Build Orientations
(Multidisciplinary Digital Publishing Institute (MDPI), 2026) Dede, Merve; Saygılı, Sina; Topçuoğlu, Nursen
This study evaluated the combined effects of build orientation, layer thickness, and polishing protocols on surface roughness and bacterial adhesion of occlusal splints. Ten disc-shaped specimens (Ø16 × 3 mm) were fabricated for each group using a digital light processing (DLP)-based 3D printer. Specimens were printed at two orientations (0° and 90°) and two layer thicknesses (50 and 100 µm) using a splint resin. Surface roughness was measured with a contact profilometer, and bacterial adhesion was measured by optical density (OD) readouts for Streptococcus mutans using a spectrophotometer. Surface morphology was examined by field-emission scanning electron microscopy (SEM). Statistical analyses were performed using jamovi. Because normality and/or homogeneity assumptions were not met, robust analysis of variance was applied. Polishing protocol significantly affected surface roughness (Ra) values. Unpolished specimens showed the highest Ra values, whereas mechanical polishing combined with centrifugation produced the lowest values. No significant main effects of polishing protocol, layer thickness or orientation were observed for bacterial adhesion. SEM findings supported the roughness results. Surface roughness was primarily influenced by polishing protocols and their interactions, whereas bacterial adhesion remained relatively stable. The weak Ra–OD correlation indicated that surface roughness alone was not a reliable predictor of bacterial adhesion.
Comparison of W. Arnett’s cephalometric analysis measurements performed using artificial intelligence and manual measurements
(Springer Science and Business Media Deutschland GmbH, 2026) Kula, Betül; Polat, Elif Nadide Akay
Objectives: This study aimed to compare the linear and angular Arnett cephalometric measurements obtained from WebCeph Premium™ with those from manual cephalometric analysis and to assess the reliability of the automated measurements. Methods: Thirty-two pre-treatment lateral cephalograms of patients were randomly selected. Images were calibrated, 29 landmarks were manually traced, and 40 parameters were recorded by two orthodontists (6 angular, 34 linear). WebCeph Premium™ (version 2.0.0, AssembleCircle Corp., Gyeonggi-do, Republic of Korea) automatically identified landmarks and performed Arnett’s cephalometric analysis. After 15 days, orthodontists reassessed the radiographs. Reliability and repeatability were evaluated using the intraclass correlation coefficient (ICC), which exceeded 0.95, indicating excellent agreement. Normality was assessed using the Shapiro–Wilk test, and group comparisons were performed with paired t-tests. Results: For Researcher 1, initial ICC values ranged from 0.003 to 0.984 and final values from 0.617 to 0.996. For Researcher 2, initial ICC values ranged from 0.022 to 0.999 and final values from 0.601 to 0.999. Inter-observer ICC values ranged from 0.03 to 0.984, with most measurements showing high agreement. Manual tracing and WebCeph Premium™ showed high agreement, with ICC values ranging 0.913 and 0.995. Conclusions: WebCeph Premium™ demonstrates high concordance with manual Arnett analyses; however, further refinement of certain parameters is necessary to enhance AI precision. Clinical Relevance: The utilization of WebCeph Premium™ within clinical settings has the capacity to enhance the efficiency of cephalometric analysis for orthognathic cases by minimizing manual workload and inter-examiner variability. This can result in more consistent and efficient treatment planning. © The Author(s) 2026.
Dimensional and cross-sectional compatibility of contemporary nickel–titanium files and their corresponding gutta-percha cones: A micro-computed tomography study
(Springer International Publishing, 2026) Sarkan, Cem; Haznedaroğlu, Faruk
This study aimed to evaluate the dimensional and sectional compatibility between contemporary nickel–titanium (NiTi) root canal instruments and their corresponding gutta-percha (GP) cones with variable tapers, and to assess their compliance with ISO and ADA standards using micro-computed tomography (Micro-CT). Four NiTi file systems (ProTaper Next X2, HyFlex EDM OneFile, Reciproc Blue R25, and WaveOne Gold Primary) were analyzed. Their compatibility with corresponding GP cones was assessed based on diameter and taper measurements at 1 mm intervals (D1 to D16). Measurements were performed using Micro-CT imaging, and data were analyzed using descriptive statistics, independent t-tests, and one-way ANOVA with Bonferroni post hoc tests (p<0.05). Compliance with International Organization for Standardization (ISO) and American Dental Association (ADA) standards was also assessed. The findings reveal significant dimensional discrepancies between files and GP cones, with GP cones generally exhibiting larger diameters. Reciprocating systems (WaveOne Gold and Reciproc Blue R25) demonstrated superior compatibility with GP cones compared to rotary systems (ProTaper Next and HyFlex EDM OneFile). GP cones adhered more closely to ISO and ADA standards than files. Significant mismatches were identified between NiTi instruments and their corresponding GP cones. Reciprocating systems showed better dimensional compatibility than rotary systems. These results highlight the need for careful evaluation of material pairing to ensure optimal clinical performance.
Aesthetic efficacy of resin infiltration on post-orthodontic white spot lesions using different conditioning methods: 24-month randomized control follow-up
(Allen Press Inc., 2026) Karaman, Emel; Ünsal, Kübra Alan; Öz, Aslıhan Zeynep; Öz, Abdullah Alper; Ercin, Özlem
Objectives: To assess color and fluorescence changes in post-orthodontic white spot lesions (WSLs) using different surface conditioning methods from prior to resin infiltration to a 24-month follow-up. Materials and Methods: Thirty patients, each with a minimum of four WSLs with ICDAS (International Caries Detection and Assessment System) II code 1 and 2 after bracket debonding were included. After baseline (T0), the lesions were randomly divided into four groups: regular brushing, 15% HCl (hydrogen chloride) gel, 37% H3PO4(phosphoric acid) gel, and Er:YAG (erbium-doped yttrium aluminium garnet) laser. Icon resin infiltration was applied. In the treatment groups, color and fluorescence were reexamined just after the resin infiltration treatment (T1), and after 6 (T2) and 24 months (T3). Results: There were no significant fluorescence or color changes between the treatment groups for the different time intervals. The control group showed a significantly lower color change from T0 to T2 and T0 to T3 than all the treatment groups whereas, at T2–T3, the control group showed the greatest improvement. Conclusions: Resin infiltration caused greater esthetic improvement and more revival of the lost fluorescence than daily brushing. HCl gel, H3PO4gel, and Er:YAG laser are adequate conditioning methods for resin infiltration of post-orthodontic WSLs with ICDAS II code 1 and 2. (Angle Orthod. 2026;96:311–317.). © 2026, Allen Press Inc. All rights reserved.
Comparison of color stability and wear resistance of different 3D printed definitive restorative resins
(2026) Gündoğan, Zülal Çoban; Özyılmaz, Özgün Yılmaz; Kara, Özlem
Statement of problem: Subtractive manufacturing in computer-aided design and computer-aided manufacturing (CAD-CAM) systems has been extensively studied, but additive manufacturing materials, particularly those used for definitive restorations, are relatively new and data regarding their clinical performance remain limited. Purpose: This in vitro study aimed to evaluate the color stability of 3 different 3-dimensionally (3D) printed definitive restorative materials under 5 different Commission Internationale de l'Eclairage illuminants and to compare their metameric color differences. In addition, the mechanical wear resistance of these materials was evaluated independently. Material and methods: A total of 135 specimens with thicknesses of 1.0, 1.5, and 2.0 mm were 3D printed according to the manufacturers' protocols. Color was evaluated before and after thermocycling under 5 illumination conditions (D65, D50, A, F11, F2). ΔE00 values were analyzed using mixed-design analysis of variance (α=.05). Wear was evaluated in 2.0-mm specimens using simulated mastication and volumetric analysis, and the wear data were analyzed using the Kruskal-Wallis test (α=.05) RESULTS: All specimens exposed to illuminant A exhibited clinically unacceptable color changes, regardless of material type or thickness. Under illuminants D50, F11, and F2, color changes were perceptible but remained within clinically acceptable limits. Thermal aging significantly reduced ΔE00 values (P=.001). Although wear was observed in all groups, no significant differences were found in volumetric loss (P=.139). Conclusions: Illuminants significantly influenced color stability across all resin types and thicknesses, whereas increased restoration thickness was associated with reduced color change perceptibility. In addition, no significant differences in wear volume were found among the tested 3D-printed definitive restorative materials.
Comparison of tensile bond strengths of different impression materials used with custom trays fabricated by 3D printing
(2026) Topalan, Onur; Özyılmaz, Özgün Yusuf
Background: This study aimed to evaluate and compare the tensile bond strength between four different impression materials and custom trays fabricated using various photopolymer-based threedimensional (3D) printing materials and one conventional method. Additionally, the effect of three surface treatments on bond strength was investigated. Methods: A total of 288 custom tray specimens were fabricated using four different techniques: Stereolithography (SLA), liquid crystal display (LCD), digital light processing (DLP), and a conventional light-cured urethane dimethacrylate (UDMA)-based acrylic. Each tray type was subjected to three surface treatments: adhesive-only, perforated-only, and perforated + adhesive. Four elastomeric impression materials were tested: polyvinylsiloxane, condensation silicone, polyether, and vinylsiloxanether. A standardized CAD model was used for all trays. The impression materials were applied onto the tray surfaces, and tensile bond strength was tested using a universal testing machine. Each condition was tested with six replicates (n = 6). Data were recorded in Newtons and converted to megapascal (MPa) using a standardized bonding surface area of 825 mm². Three-way ANOVA and Tukey’s post-hoc tests were conducted (α=0.05). Results: All three independent variables - printing technique, surface treatment, and impression material - had a statistically significant effect on tensile bond strength (p < 0.001). The highest mean bond strength (0.272 MPa) was observed with the DLP-printed tray using perforatedonly and polyether impression material. The lowest value (0.018 MPa) was found with the same tray type and surface treatment, but with condensation silicone. Among surface treatments, adhesive-only and adhesive + perforated trays showed significantly higher bond strengths compared to perforated-only groups (p = 0.001). Polyether showed significantly higher bond strength than all other impression materials, while condensation silicone yielded the lowest. Conclusions: Within the limitations of this in vitro study, tray fabrication method and surface treatment significantly influenced bonding with impression materials. The present findings may provide useful preliminary data for future clinical investigations evaluating retention characteristics of 3D-printed custom trays.
Volumetric Three-Dimensional Evaluation of the Pharyngeal Airway After Orthognathic Surgery in Patients with Skeletal Class III Malocclusion
(MDPI, 2025) Öz, Aslıhan Zeynep; El, Hakan; Öz, Abdullah Alper; Palemo, Juan Martin
Background: Orthognathic surgery significantly alters the dimensions of the pharyngeal airway. This study’s objective was to assess alterations in the pharyngeal airway volume via cone-beam computed tomography (CBCT) after orthognathic surgery in patients with skeletal Class III malocclusion. Methods: This retrospective study analyzed CBCT images from 23 patients with skeletal Class III malocclusion (13 females, 10 males), who were categorized into two groups based on the surgical approach: double-jaw and single-jaw surgery. The double-jaw group included 13 patients who underwent bilateral sagittal split osteotomy (BSSO) and Le Fort I osteotomy, whereas the single-jaw group included of 10 patients who had underwent BSSO only. CBCT images were evaluated both before surgery and at a minimum of three months after surgery. The oropharyngeal volume (OP), nasopharyngeal volume (NP), total airway volume, posterior airway space (PAS), and the most constricted area at the base of the tongue (minAx) were measured. Statistical analyses were performed using either paired t-tests or Wilcoxon signed-rank tests depending on data normality, with a significance level set at p < 0.01. Results: In the double-jaw group, a significant volumetric increase was observed in the nasopharynx (5316 ± 1948 mm3 to 6064 ± 1899 mm3 ; p = 0.010) and oropharyngeal volume decreased from 17,097 ± 5675 mm3 to 14,290 ± 5835 mm3 ; however, this reduction was not statistically significant (p = 0.017). In contrast, the single-jaw group showed a significant reduction in oropharyngeal volume from 15,620 ± 5040 mm3 to 12,444 ± 4701 mm3 (p = 0.010), with no significant change in nasopharyngeal volume (p = 0.551). Total airway volume significantly decreased only in the single-jaw group (from 20,452 ± 7754 mm3 to 16,846 ± 6529 mm3 , p = 0.010). Additionally, both groups exhibited marked decreases in PAS and minimum axial area values (all p < 0.01). Conclusions: Orthognathic surgery led to a significant volumetric increase in the nasopharynx in the double-jaw group, whereas the oropharynx volume significantly decreased only in the single-jaw group. Additionally, both surgical approaches resulted in a marked reduction in PAS and minimum axial area values, highlighting a notable impact on posterior airway dimensions.
Investigation of factors influencing patients’ preferences for traveling to Türkiye for dental tourism: The case of a private hospital
(2026) Keleş, Zeynep Hale; Ertuğrul, Mustafa Orkun; Tunçer, Jale
Aim: This study aimed to investigate why dental tourists choose Türkiye for their dental clinic visits; specifically looking at a private hospital in Istanbul. Methods: This cross-sectional study employed a face-to-face survey method conducted through an interpreter with foreign patients who applied to the dental clinic of a private hospital in Istanbul (n = 52) between March 24; 2023; and February 29; 2024. The questionnaire comprised 29 inquiries aimed at collecting the participants’ demographic characteristics; elucidating their motivations for selecting Türkiye as a destination for dental care; and describing their experiences throughout the treatment process. The inquiries were presented in single-choice and multiple-choice formats. Results: Approximately 94% of dental tourists chose Türkiye for its price advantage; 86% for shorter treatment times; 82% for trust in the dentist; 78% for easy appointment scheduling; 60% for advanced technology; and 52% for low travel costs. African patients cited high costs; poor technology; appointment challenges; inadequate education; and hygiene issues as reasons for not seeking treatment in their home countries. Furthermore; European visitors cited high prices and difficulty obtaining appointments as their primary concerns; while all Middle Eastern respondents reported that obtaining an appointment was difficult. Although 77.4% of dental tourists accessed this hospital through an agency; 53.8% communicated with previous visitors to Türkiye; and 84.6% conducted research via social media. Conclusions: Within its limitations; the study concluded that affordable treatment costs; confidence in the experience of dental professionals; short treatment durations; and overall accessibility were the primary factors influencing patients’ decision to choose Türkiye for dental tourism. The reasons African patients did not seek dental care in their home country included inadequate training of dentists; unavailability of specific treatments; and poor hygiene. Travel agencies; word of mouth; and social media influenced dental tourists’ decision-making processes.
Color matching and metameric behavior of composite resins applied on anodized titanium surfaces: an in vitro spectrophotometric study
(2026) Davut, Umur; Özyılmaz, Özge Doğanay; Özyılmaz, Özgün Yusuf
Background The aim of this study was to evaluate the color matching and metameric behavior of two different composite resins applied to titanium surfaces anodized to yellow and pink colors. The study aimed to determine the effects of anodization color and composite resin type on color performance in hybrid prosthesis and screw access hole closure applications. Materials and methods A total of 72 Grade 5 titanium discs (10 mm diameter × 2 mm thickness) were allocated to three anodization conditions: nonanodized/gray (0 V, n = 24), yellow (55 V, n = 24), and pink (80 V, n = 24). Each anodization group was subdivided into two subgroups: 3 M Filtek Z250 (microhybrid) and Tokuyama Estelite Sigma Quick (supra-nano hybrid) composite resins (A2 shade, 2 mm thickness; n = 12 per subgroup). Gray titanium + composite specimens were used as the reference for ΔE₀₀ calculations; yellow and pink anodization groups constituted the experimental groups. Color measurements were performed using a spectrophotometer (Konica Minolta CM-3700 A) under four light sources (D65, D50, incandescent A, and F11). Data were analyzed using mixed-design repeated-measures ANOVA, Bonferroni post hoc test, and independent samples t-test (α = 0.05). Results Anodization color (η² = 0.941) and composite type (η² = 0.952) demonstrated strong effects on ΔE₀₀ values (both p < 0.001). Light source showed statistically significant but clinically negligible effect (η² = 0.521, mean difference < 0.1 ΔE₀₀). Pink anodization exhibited higher color differences than yellow (2.84–2.99 vs. 1.53–1.62), and Tokuyama composite higher than 3 M (2.89–3.12 vs. 1.41–1.54) (both p < 0.001). Yellow+3 M combination showed lowest values (0.91–0.97), while Pink+Tokuyama showed highest (3.68–3.97). Metamerism index remained minimal (MI < 0.21). Conclusions Careful material selection is essential for optimal esthetics in anodized titanium-composite systems. Yellow anodization combined with a microhybrid composite demonstrated the most favorable color matching performance under
Influence of Thermal Aging on the Marginal/Internal Fit of Incisor Veneered and Monolithic Zirconia Crowns
(Wiley, 2026) Özkurt Kayahan, Zeynep; Özden, Yunus Emre; Çelikyürek Karabağlı, Zeynep; Özyılmaz, Özgün Yusuf; Özer, Füsun; Blatz, Markus B.
Objectives: The aim of the study was to evaluate and compare the effect of thermal aging on the marginal and internal adaptation of veneered and monolithic zirconia (MZ) crowns. Materials and Methods: A maxillary central incisor abutment was digitally designed, fabricated using resin, and scanned for crown design. MZ (IPS e.max ZirCAD Prime Esthetic) and veneered zirconia (VZ; coping: Everest, KaVo; layering: IPS e.max Ceram) crowns were fabricated (n=10). STL files were analyzed in Geomagic Design X to calculate root mean square (RMS) values within the selected marginal and internal regions before and after 10,000, 30,000, and 50,000 thermal cycles with superimposition. Data were analyzed using Shapiro–Wilk and Mann–Whitney U tests. The comparison of thermal aging treatments was evaluated using the Friedman and post hoc Wilcoxon signed-rank tests (p<0.05). Results: Significant differences were found between MZ and VZ crowns (p<0.05). In the MZ group, marginal gaps increased from 104μm (T0) to 115μm (T3), and internal gaps from 122μm (T0) to 146μm (T3). In the VZ group, marginal gaps increased from 82μm (T0) to 128μm (T3) and internal gaps from 136μm (T0) to 204μm (T3). VZ crowns showed higher dimensional changes than MZ crowns. Conclusions: Thermal cycling significantly affected the fit of zirconia crowns. VZ crowns exhibited greater dimensional changes after 30,000 and 50,000 thermal cycles, while MZ crowns maintained superior marginal fit during the same periods. Clinical Significance: This study highlights the influence of thermal aging on the marginal and internal adaptation of veneered and MZ crowns. VZ may be more susceptible to marginal or internal discrepancies after thermal aging, when compared with the MZ.

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