Examinando por Autor "Escribano, Nuria"

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Aging Effect on Push-Out Bond Strength of Six Resin Cements: An In Vitro Study
(MDPI, 2025-03-20) Baena, Eugenia; Escribano, Nuria; Fuentes, Victoria; Reche, Isabel; Ceballos, Laura
The number of resin cements marketed for fiber post cementation has increased significantly. This study compared the push-out bond strength (PBS) of self-adhesive and universal resin cements used to lute fiber posts at 24 h and after 6 months of aging in artificial saliva. Fiber posts were luted to eighty human roots endodontically treated with four self-adhesive/one-step resin cements, with one of them also used in combination with its appropriate tooth primer; one universal resin cement, applied as one-step or together with its corresponding universal adhesive (multi-step); and one adhesive/multi-step resin cement, as a control. After storage (24 h or 6 months), the interfaces were subjected to PBS tests and the data were analyzed by two-way ANOVA and Tukey and Student’s t-tests (p < 0.05 defined as statistical significance). The results showed that Scotchbond Universal Plus + RelyX Universal attained statistically higher values at 24 h and 6 months. At 24 h, all resin cements yielded similar PBS to root dentin, while at 6 months, NormoCem obtained the lowest PBS. Storage for 6 months significantly decreased PBS for NormoCem and Multilink Automix. Root section did not influence PBS regardless of storage time. It was concluded that PBS is resin cement dependent. The universal resin cement, RelyX Universal, applied in combination with Scotchbond Universal Plus adhesive, obtained a higher and more stable PBS than the other resin cements tested.
Factors influencing the agreement between teachers and students in the assessment of preclinical endodontics using a rubric
(BioMed Central, 2025-04-28) Baracco, Bruno; Escribano, Nuria; Da Silva, Dayana; Belliard, Virginia; Ceballos, Laura; Fuentes , Victoria
Background: Students' self-assessment and rubrics are pedagogical tools designed to enhance learning and evaluation processes. Achieving convergence between learners and teachers is paramount during the learning of complex treatments such as endodontic procedures, although it can be challenging due to uncontrollable factors that may affect task performance and perception. This study aimed to evaluate the influence of various factors (anatomical difficulty, type of instrumentation system, and training level) on the assessments of root canal treatments (RCT) by teachers and students using a rubric, and to determine the degree of agreement between them. Methods: 144 RCT were performed on extracted human molars by 36 dental students using two mechanized systems and subsequently evaluated using a rubric by both the students and four teachers. Rubric yielded a total score for the sum of 4 items analyzed individually: radiographic evaluation, access cavity, instrumentation, and obturation. The influence of the three following factors: anatomical difficulty (categories: minimal, moderate and high), instrumentation system (categories: Protaper Next and Reciproc Blue), and training level (categories: initial and advanced) on teachers' and students' RCT total scores and for each item were analyzed by three-way ANOVA. Agreements between teachers and students were measured by intraclass correlation coefficients and quadratic weighted Kappa. Statistical analyses were conducted at a pre-set alpha of 0.05 using Stata 16. Results: No significant influence of anatomical difficulty, instrumentation system, or training level was observed on RCT total scores given by teachers and students (p > 0.05). However, training level influenced the assessments by teachers in instrumentation as those by students in radiographic evaluation. Agreement was moderate for RCT total scores and substantial for teeth with minimal or high difficulty, after using Protaper Next, and at the initial training level. Agreement was substantial in obturation, and moderate in radiographic evaluation, access cavity, and instrumentation. Some categories in instrumentation and obturation items showed substantial agreement, while fair agreement was observed only in access cavity. Conclusions: Educational factors in Endodontics such as anatomical difficulty, mechanized instrumentation system, and level of training did not influence the total scores of preclinical RCT by teachers or students. Agreement for RCT total scores ranged from moderate to substantial. The strongest agreement was observed in obturation, while access cavity yielded the lowest. The rubric as an assessment tool in Endodontics teaching is recommended.
Microtensile Bond Strength of Self-adhesive Luting Cements to Ceramic
(Quintessence Publishing, 2006-10) Escribano, Nuria; De la Macorra, José Carlos
Purpose: To test the null hypothesis that three self-adhesive luting materials had the same microtensile bond strength when used to lute ceramic IPS Empress II disks to the dentin of perfused teeth. Materials and Methods: Occlusal enamel and the roots of 9 human third molars were removed and crown segments connected to a perfusion system (30 cm H2O). Nine ceramic disks (IPS Empress II) were prepared, conditioned with 5% FH (20 s), rinsed with water, and air dried. A primer silane agent was applied (Monobond-S) for 60 s and air dried. Teeth were bonded to disks using one of three materials: Multilink System, RelyX Unicem, or Panavia F light. Specimens were vertically sectioned to obtain square bars. Each bar was fixed to a rigid custom-made tensile device and submitted to tensile force until debonding. Microtensile bond strength (μTBS) was given in MPa. Because the means of bonded areas (BA) were different between groups, it was impossible to compare μTBS results directly. Thus, the regression line TBS(MPa) = -2.15 + [19.92 / BA(mm2)] was calculated to correlate μTBS results and BA. Residuals (difference between the value estimated by the regression line and the actual value) were stored as “distances”. ANOVA was performed to examine the statistical significance of differences between group’s means distances, and the Tamhane’s post hoc test was used to locate eventual differences. Results: The number of bars used in the analysis was n = 147. Residuals should not be statistically different if the null hypothesis (represented by the regression line) was credible. ANOVA showed statistically significant differences between the distances of the groups’ means (p < 0.00001). Tamhane’s post hoc test (p < 0.05) showed that different group means were RelyX < Multilink < Panavia F. Conclusion: The null hypothesis was rejected: materials showed different tensile bond strengths. Panavia F obtained highest bonding values, followed by Multilink System. RelyX Unicem, the only material that does not require pretreatment of dentin, achieved the lowest TBS values under these study conditions.
The influence of irrigation solutions in the inorganic and organic radicular dentine composition
(Wiley, 2020-01-26) Barón , Marta; Morales, Victoria; Fuentes, Victoria; Linares, María; Escribano, Nuria; Ceballos, Laura
The aim of this study was to analyse changes in radicular dentine composition after different irrigation regimes using attenuated total reflectance Fouriertransform infrared spectroscopy (ATR-FTIR). Dentine slices from human single-root teeth were immersed in: (i) 5.25% sodium hypochlorite (NaOCl) for 1, 5 and 20 min; (ii) 17% EDTA for 1 min; and (iii) 5.25% NaOCl for 20 min, and 17% EDTA and 5.25% NaOCl, both for 1 min. Carbonate/mineral, Amide I/mineral and Amide III/CH2 ratios were determined using ATR-FTIR before and after immersion in the irrigation solutions tested. Results showed that 5.25% NaOCl significantly decreased carbonate/mineral, Amide I/mineral and Amide III/CH2 ratios (P < 0.05). Application of 17% EDTA produced no change in carbonate/mineral ratio (P = 0.120), while an increase in Amide I/mineral in apical third (P = 0.002) and Amide III/CH2 (P < 0.001) was observed. The combination of NaOCl, EDTA and NaOCl increased carbonate/mineral ratio in coronal third (P = 0.037), and Amide I/mineral (P = 0.003) and Amide III/CH2 (P = 0.001) ratios. In conclusion, irrigation solutions tested significantly affected radicular dentine composition.