The aim of this in vitro study was to evaluate the effect of the pre-application of a dentin-bonding agent and the application of different lasers on the prevention of tooth discoloration caused by mineral trioxide aggregate (MTA) in the presence of blood. Sixty extracted human anterior teeth were selected, with root lengths standardized to 10 mm and root canals shaped using Gates-Glidden drills #3 to #5. The samples were divided into six groups (n = 10): Group 1 with no surface treatment and Groups 2 to 6 with Optibond universal adhesive and Neodymium yttrium aluminum garnet (Nd:YAG), Erbium yttrium aluminum garnet (Er:YAG), Erbium-chromium-yttrium-scandium-gallium-garnet (Er:Cr:YSGG), and diode laser applications, respectively. Root canals were filled with fresh human blood, and ProRoot MTA and a collagen barrier were then placed. Color changes were measured with a spectrophotometer at 0, 7, 30, 90, and 180 days post MTA placement. Color differences (∆E) were analyzed using a two-factor mixed-design ANOVA with the Sidak method (p = 0.05). All treatment groups exhibited discoloration above the acceptability threshold. Although all treatment approaches exhibited less color change compared to the control group (p < 0.05), there was no significant difference among them in terms of preventing color change (p > 0.05). It was determined that none of the methods could guarantee 100% prevention of discoloration caused by MTA–blood contact.

Background: In dentistry, 3-dimensional (3D) printed permanent resin materials are widely used due to their durability and aesthetic versatility. However, their response to acidic environments, such as exposure to gastric acid in conditions like gastroesophageal reflux, is not yet fully understood. This study investigates the impact of simulated gastric acid on the color stability and surface roughness of 3D-printed permanent resin materials. Methods: A total of 60 specimens (n= 15 in each group) were prepared as disc-shaped specimens using 4 different 3D-printed permanent resins: VarseoSmile TriniQ (VST), Crowntec (CR),C&B Ceramic Resin (CB), and Permanent Crown (PB). The specimens were exposed to a simulated gastric acid solution (pH 1.2) at 37°C for 18 hours, and color change (ΔE) was measured by a spectrophotometer, and surface roughness (Ra) was measured by a contact profilometer. Results: After gastric acid exposure, color change (ΔE) in all groups remained within clinically acceptable limits (ΔE <3.3). However, significant differences in surface roughness were observed depending on the material type. The CB group showed higher surface roughness compared to the other groups (P < .05). Conclusion: The 3D-printed permanent resins maintained color stability under gastric acid exposure, while surface roughness varied depending on the material composition. These findings highlight the importance of material selection, especially for patients with acidic oral environments. Cite this article as: Dinçer G, Şeşen P. Effect of gastric acid on surface roughness and color stability of 3D-printed permanent resins. Essent Dent. 2025, 4, 0042, doi: 10.5152/EssentDent.2025.25042.

The aim of the present study was to evaluate the effect of the pre-application of dentin bonding agent and laser application on the prevention of tooth discoloration caused by (MTA) in the presence of blood. Fifty extracted human anterior teeth were prepared by standardizing root lengths to 10 mm and shaping root canals. Specimens were divided into five groups (n = 10) based on the treatment applied to the pulp chamber dentin wall: Group 1/no surface treatment; Group 2/Optibond FL; Group 3/Clearfil SE; Group 4/Optibond Universal adhesive application; Group 5/Nd:YAG laser application. Root canals were filled with fresh human blood below the cemento-enamel junction (CEJ), followed by ProRoot MTA, and collagen barrier placement. Color changes were monitored using a spectrophotometer at 0, 7, 30, 90, and 180 days post MTA placement. Color differences (∆E) were calculated and analyzed using two-factor mixed-design ANOVA with Sidak adjustment at p = 0.05. The degree of coloration increased with time within each group (p < 0.05). No significant differences were observed between Optibond FL and Optibond Universal within each time interval, or between Clearfill SE Bond and the control group (p > 0.05). When compared to the control group, the Nd YAG group exhibited the least degree of discoloration in all time intervals (p < 0.05). Although the Nd:YAG laser had promising results, none of the methods can guarantee a 100% prevention of discoloration resulting from tooth discoloration caused by MTA-blood contact.

Background: The aim of the study was to identify whether differences existed in the aesthetic perception of anatomical variations of the face and teeth among dental students, based on factors such as education level, gender, and the presence of a dentist in the family. Methods: The study was carried out with dental students using the Google Forms platform. A young female model was selected for the survey, with no aesthetic-compromising restorations or pathologies in her maxillary anterior teeth. Standard facial and smile reference photographs were digitally manipulated to alter specific aesthetic features using professional image-editing software (Adobe Photoshop v.20.0.0, Adobe Inc., San Jose, California, USA). Participants evaluated these photographs, focusing on components such as facial symmetry, gingival position, buccal corridor, and occlusal plane angulation. Preclinical and clinical students rated the original and manipulated images on a scale from 1 to 5, with 5 representing the most aesthetically acceptable image and 1 representing the least pleasing one. Statistical analysis comprised Shapiro-Wilk test, Levene test, Mann-Whitney U test. Results: In the research, 493 students participated, including 240 clinical students; 312 were female, and 89 had a dentist in their family. The overall aesthetic perception score was high (82.63 ± 8.5). Clinical students demonstrated significantly better perceptions of midline diastema, occlusal plane inclination, clinical crown height, and dental modifications compared to preclinical students (p < 0.05). Female students scored higher in lower facial height perception than males (p = 0.014). The presence of a dentist in the family did not significantly influence aesthetic perception (p > 0.05). Conclusion: Clinical training positively impacted students’ ability to critically analyze aesthetics while maintaining function and naturalness. It can be suggested that, as the academic level increases in dental education, students’ aesthetic judgment skills also improve.