Marta Macarena Paz-Cortés

Background: Instrumental shade determination may reduce some sources of subjectivity associated with visual shade selection, but device repeatability and interchangeability remain clinically relevant concerns. Objective: The aim of this study was to evaluate the reproducibility and clinical utility of two spectrophotometric devices (Easyshade and Rayplicker Cobra) for tooth shade measurement and selection. Methods: In total, 35 adults were evaluated at seven predefined maxillary tooth regions: the cervical, middle, and incisal thirds of teeth 2.1 and 2.3, and the middle third of tooth 2.6. Each instrumental measurement was repeated three times, with complete removal and repositioning of the device between readings. Visual shade selection using the VITA Classical guide was performed once per site by the same trained operator, whose normal colour vision had been confirmed before data collection. Teeth were kept hydrated, patients remained in the same position, and both devices were calibrated according to the manufacturers’ instructions. Intra-device strict repeatability and inter-method agreement were assessed descriptively and using Cohen’s Kappa, as appropriate. Results: Descriptive pooled strict repeatability was 52.2% for Easyshade and 53.1% for Rayplicker Cobra. Repeatability varied by tooth and region. Inter-device agreement was predominantly slight to fair (0.053–0.386). Easyshade showed moderate-to-substantial agreement with the visual comparator in selected regions, with the highest Kappa in the middle third of tooth 2.1 (0.619), whereas Rayplicker Cobra did not exceed fair agreement (maximum 0.362). Conclusions: Both spectrophotometers showed similar descriptive strict repeatability percentages; however, their low inter-device agreement indicates that their categorical shade outputs should not be considered interchangeable. The greater agreement of Easyshade with VITA Classical in selected regions reflects inter-method comparability rather than superior trueness, as no independent instrumental reference standard was used.

The aim was to evaluate ion release from various brackets and tubes, considering manufacturing methods and alloy composition. An experimental in vitro study was conducted following UNE-EN ISO 10,271:2020 and ISO 27,020 standards. The sample included 120 brackets and 32 tubes, divided into: Group 1 (control solution), Group 2 (MIM brackets), Group 3 (CAD-CAM brackets with welded mesh), Group 4 (CAD-CAM monoblock brackets), Group 5 (MIM tubes), and Group 6 (CAD-CAM tubes). Two sets per bracket and tube type were tested, with triplicate measurements per sample. Devices were immersed in a lactic acid and NaCl solution (pH 2.34) for 7 days at 37 °C. Ion release (Ni, Cr, Cu, Mo, Mn, Si) was quantified using inductively coupled plasma optical emission spectrometry (ICP-AES). Statistical analysis included Kruskal-Wallis and post hoc tests (p < 0.05). Significant differences were found in ion release among bracket types. Group 2 (MIM) showed the highest Ni release (mean ± SD: 2.59 ± 0.35 µg/ml), Cr (7.05 ± 0.73 µg/ml), and Cu (2.35 ± 0.28 µg/ml), with p < 0.001. CAD-CAM monoblock brackets (Group 4) exhibited the lowest levels across all elements. No significant differences were observed between tube groups and the control (p > 0.05). As a conclusion, orthodontic devices release trace metal ions, with CAD-CAM monoblock brackets showing superior corrosion resistance.

Purpose: To evaluate the oral health status of children aged 3– 14 years in the Community of Madrid, Spain, between 2017 and 2020, and to identify associated protective and risk factors. Methods: A cross-sectional, descriptive, and analytical study was conducted in 39 schools. Clinical examinations followed WHO guidelines and included caries detection (ICDAS codes 4– 6), enamel developmental defects (DDE), tooth wear, malocclusion, and oral hygiene indicators. Sociodemographic data and oral hygiene habits were collected via parental questionnaires. Schools were stratified by socioeconomic status (SES). Statistical analyses were performed using SPSS v29 with a 95% confidence level (p < 0.05). Results: Data from 11,646 children (mean age: 8.46 ± 1.99 years) revealed that 40.65% had caries in at least one tooth, and 9.42% had five or more affected teeth. Caries prevalence was higher among preschoolers (48.7%) than school-aged children (40.3%). Dental restorations were present in 10.5%, while only 11.7% had at least one sealant and 4.8% had all first permanent molars sealed. DDE affected 11% of children (mild: 8.1%, moderate: 2.5%, severe: 0.4%), tooth wear 4%, dental trauma 2%, and malocclusion 41.4%. Visible plaque was observed in 62.6% of participants, despite 50.5% reporting twice-daily brushing and 29.6% brushing three or more times per day. SES strongly influenced caries prevalence: 69.4% of children from low SES backgrounds had decayed teeth compared to 23.1% and 7.5% in medium and high SES groups, respectively. Logistic regression identified low SES (odds ratio (OR)=1.53, 95% CI: 1.03– 2.28) as a risk factor for caries development, while absence of malocclusion (OR=0.54, 95% CI:0.32– 0.93) and absence of visible plaque (OR=0.32, 95% CI: 0.20– 0.51) as protective factors in preschool children. In school-aged children, low SES (OR = 3.66; 95% CI:3.21– 4.18) increased the odds of caries; while toothbrushing ≥ 2 times/day showed a protective effect (OR range = 0.19– 0.23) and absence of visible plaque (OR = 0.59; 95% CI:0.55– 0.65 for absence vs presence). Conclusion: Caries remains highly prevalent among children in Madrid, particularly in socioeconomically disadvantaged groups, highlighting the urgent need for targeted preventive strategies.

Introduction: Digital impression techniques have gained popularity in dentistry due to their potential advantages in accuracy, efficiency, and patient comfort. This systematic review aims to evaluate and compare the accuracy, chairside time, and patient perception of conventional vs. digital impressions. Methods: A systematic search was conducted in Medline/PubMed, EBSCO, Web of Science, and Scopus databases. Inclusion criteria comprised clinical or in vivo studies comparing conventional and digital impression techniques in terms of accuracy, working time, and/or patient comfort. Reviews, meta-analyses, editorials, and studies involving fully edentulous patients or edentulous spans exceeding two teeth were excluded. Study quality was assessed using the QUADAS−2 tool, and intra-operator agreement was evaluated using the Cohen's Kappa statistic. Results: From 269 initially identified articles, 10 met the inclusion criteria. All studies assessed accuracy; only two evaluated working time and patient comfort. The included studies, published between 2016 and 2024, were cross-sectional observational in design, with sample sizes ranging from 5 to 50 participants. A variety of intraoral scanners were evaluated, including Cerec, Trios, iTero, and Primescan. The QUADAS-2 tool indicated an overall unclear risk of bias in patient selection and mixed concerns regarding applicability. While findings on accuracy were mixed, most studies concluded that both techniques are clinically acceptable, with conventional impressions performing better in full-arch cases. Digital impressions were consistently reported as faster and more comfortable for patients. Limitations: The findings of this review should be interpreted with caution due to methodological heterogeneity, small sample sizes, and the inclusion of predominantly young, fully dentate participants. Conclusion: Intraoral scanners offer advantages in workflow efficiency and patient experience, although conventional impressions remain reliable and widely used. The variability in study designs and outcome measures underscores the need for standardized evaluation protocols in future research. Systematic Review Registration: https://doi.org/10.17605/OSF.IO/62RCY .

The aim was to analyse the efficacy of Endogal Kids ^® rotary files in removing root canal filling. Methods: A cross-sectional in vitro study was conducted ( n = 10 primary teeth). The root canals were instrumented using the Endogal Kids ^® system with 5 mL of 5% sodium hypochlorite solution and were obturated with CaOH2 and iodoform paste, Forendo™ Paste. The canal systems were retreated to remove the filling material using continuous rotation. µCT scans were performed at three time points: after canal instrumentation with rotary files (µCT-1), after root canal filling (µCT-2), and after removal of the filling material through retreatment (µCT-3). Canal void volume (CV), obturation material volume (MV), root canal void increase (ΔCV), obturation material increase (ΔMV) and filling removal volume (RV) were calculated. Statistical analysis was performed with a 95% significance level ( p ≤ 0.05). Results: Significant differences were found for CV and MV, but not for TV. The canal void volume (CV) was significantly greater at µCT-1 compared to the µCT-2 and µCT-3, with no significant difference between the µCT-2 and µCT-3 ( p < 0.001). Additionally, MV was significantly higher before removal of the filling material ( p = 0.003). No significant differences were observed in TV across the three measurements. Conclusions: This pilot study demonstrated that rotary instrumentation in primary teeth can remove a significant proportion of iodoform-based obturation material. Incisors showing greater obturation material removal, while molars exhibited more pronounced changes in canal volume.

The use of orthodontic aligners has increased significantly due to their convenience and esthetic advantages. However, understanding their microbiological behavior and cytotoxicity is essential. This study aimed to evaluate the metabolic activity (MA) and proliferation of different bacterial strains—assessed through colony-forming unit (CFU) counts—as well as the cytotoxicity of three widely used aligner systems: Spark, Invisalign, and Smile. Wettability and surface free energy (both dispersive and polar components) were determined using the sessile drop technique. The bacterial strains Streptococcus oralis, Actinomyces viscosus, Streptococcus gordonii, Enterococcus faecalis, and Porphyromonas gingivalis were cultured, and their behavior on the aligner surfaces was assessed under simulated oral cavity conditions in both aerobic and anaerobic environments using a bioreactor. Cytocompatibility was evaluated with HFF-1 human fibroblasts. Distinct strain-specific behaviors were observed. For Spark aligners, the contact angle was 70.5°, Invisalign 80.6°, and Smile 91.2°, and the surface free energy was 60.8, 66.7, and 74. 2 mJ/m², respectively, highlighting the high polar component of the Spark aligner of 31.9 mJ/m² compared to 19.3 and 20.2 mJ/m² for Invisalign and Smile, respectively. The Spark aligner exhibited the lowest metabolic activity for Streptococcus oralis (23.1%), Actinomyces viscosus (43.2%), Porphyromonas gingivalis (17.7%), and biofilm formation (2.4%), likely due to its higher hydrophilicity. The Smile aligner showed the lowest metabolic activity for Streptococcus gordonii (23.6%) and Enterococcus faecalis (51.1%), attributed to its low polar surface free energy component. CFU counts were minimal for all aligners and bacterial strains, including biofilm. All aligners demonstrated cytocompatibility above 70% (Spark: 71.0%, Invisalign: 75.7%, and Smile: 75.6%). These findings highlight the importance of considering aligner material properties in clinical practice and underscore the need for proper oral hygiene and aligner maintenance.

Aim: To assess through salivary biomarkers if clinical practices generate stress and a systemic inflammatory response in dental surgery post-graduate students.Materials and methods: A cross-sectional analytical observational study was conducted with students from the Master’s in Clinical Dentistry program. Salivary samples were collected before and after surgical procedures to quantify stress (cortisol) and inflammation biomarkers (IL-6, IL-1β, and CRP). Additionally, students completed the Perceived Stress Scale (PSS) questionnaire prior to the surgical procedure. Descriptive and analytic statistics were conducted with a 95% significance level.Results: A total analyzed sample included 21 subjects, with a mean age of 25.5 years. The influence of academic year, gender, or smoking status was none found to have a significant impact. The results show a significant decrease in cortisol levels between the pre- and post-measurements (mean difference = −108.2 ± 166.7). However, an increase in IL-6 levels was obtained (p < 0.05). High IL-6 levels were associated with elevated CRP levels. An inverse relationship was seen between perceived stress and salivary cortisol concentrations.Conclusion: The findings show a significant decrease in salivary cortisol (stress) levels and a significant increase in salivary IL-6 levels following a dental implantology procedure in postgraduate oral surgery students.

Aim: The aim of this study was to evaluate the relationship between oral hygiene (OH) efficiency and manual dexterity skills in Spanish five-year-old children using two fine motor tests. Methods: A cross-sectional study with a pre–post evaluation was designed. The children’s OH was measured according to the Silness and Löe plaque index (PI) before toothbrushing upon arrival at school (pre) and after supervised toothbrushing (post). Motor skills (children’s dexterity) were determined with the Visual Motor Skills and Resistance to Fatigue test (VMSRF test) and the scale for the Behavioural Assessment of Preschool Skills (BAPS scale). Data were analysed with the SPSS^® statistics software with a 95% confidence interval and bilateral significance. Results: One hundred and twenty-nine children were evaluated. The mean PI was 2.5, indicating generally poor OH in the sample. No difference in OH was observed between genders or in the brushing frequency categories. No significant differences in OH or the PI were found between right- and left-handed children either (p > 0.05). Significant differences were found between the OH category pre and post toothbrushing in the total sample, as well as in the various sextants and surfaces evaluated. The results of the VMSRF and BAPS tests indicate moderate visuomotor skills and fatigue resistance and a poor average skill level. A statistically significant improvement in the PI was found in children with higher scores in the VMSRF and BAPS tests. Conclusions: A significantly higher OH efficacy was found in children with better motor skills, although five-year-old children showed moderate visuomotor skills and fatigue resistance and a poor average preschool skill level.

Purpose: The aim was to analyze the accuracy of digital models and 3D-printed casts from full-arch digital impressions using two intraoral scanners (iTero^TM and Primescan^TM). Materials and methods: A crossover reliability study was designed, scanning children and teenagers with iTero^TM and Primescan^TM. Accuracy was evaluated by measuring intercanine, intermolar, and ipsilateral canine–molar distances intraorally and comparing these measurements with those from plaster casts, digital models obtained with intraoral scanners, and 3D-printed casts. A paired comparison and a general linear model with a one-way repeated measures ANOVA procedure were carried out with a confidence level of 95% (p ≤ 0.05). Results: A total of 51 subjects were analyzed (mean age 12.35 ± 2.57). Statistical differences (p < 0.05) were found in the upper and lower arch regarding accuracy in comparison to intraoral measurements, except for the iTero^TM-printed cast and canine–molar upper right and intercanine lower distances (p > 0.05 for all comparisons). Regarding a comparison between reproduction methods, the plaster cast oversized the intercanine upper distance in comparison with both intraoral scanners’ digital models and the Primescan^TM-printed cast (p = 0.001), but there were no differences in the lower arch (p > 0.05 for all comparisons). Conclusion: Intraoral scanners reproduce tooth structures with similar accuracy to conventional methods.