Shaping ability of rotary instrumentation techniques and their limitations in simulated root canals

The aim of this in vitro study was to describe the shaping ability of rotary nickel-titanium (NiTi) instruments (Mtwo, VDW, Munich, Germany) with benefi cial properties in combination with two different endodontic devices (Mtwo direct and Endo IT professional) and to compare them with Mity NiTi K-Files (Loser, Leverkusen, Germany) in combination with preparation by hand in severely curved simulated root canals of acrylic blocksThirty blocks simulating a severely curved root canal were divided into three groups (n=10 for each). All canals were prepared with NiTi fi les to an ISO size of 40 using an apical-coronal preparation technique. Mtwo NiTi fi les were used for the automatic systems, while Mity K-Files were used for the preparation by hand.</p

Comparative evaluation of microleakage among Resin-Based and nonResin-Based Restorative Materials in dentine cavities

The aim of this randomized in vitro study is to clarify whether resin based restorative materials (RBRM) behave in a way comparable to non-resin based restorative materials (non-RBRM) in dentine-limited cavities with regard to their marginal fit. For this purpose, cylindrical standardized cavities (diameter: 3.0 +/- 0.1 mm, depth: 1.5 mm) were placed on buccal surfaces of sixty human molars and restored with three non-RBRM (glass ionomer cement, amalgam, phosphate cement) and three adhesive (composite, compomer, ormocer) restoratives. Aging of the samples was achieved by thermal cycling (500 cycles). The marginal gaps could be made visible with a dye penetration test (methylene blue 2%). Using a diamond internal hole saw, 5 cuts were made through the cavity and measured under an incident light microscope at 10x magnification. The result of the statistical evaluation of the additionally determined percentage marginal gap depths was compared with the numerical evaluation of the penetration depths of 0, 1 and 2 required by the ISO test setup. The ISO classification reveals statistical differences in the penetration behaviour of phosphate cement to the other materials, whereas the statistical evaluation of the percentage measurement distances revealed significant differences between the nonadhesive and the adhesive restorative materials, with significantly smaller marginal gaps for the cavities of the RBRM group.</p

Laboratory evaluation of the potential masking of color changes produced by silver diamine fluoride in primary molars

Background: The importance of Silver diamine fluoride (SDF) as a minimally invasive and nonaerosolizing management during COVID-19 pandemic has highly increased. SDF is a caries-arresting agent that causes staining of tooth structure. Managing this discoloration will increase its acceptance in treating primary teeth. The main aim of this study was to quantify the color change associated with the application of SDF on extracted carious primary molars, the potential masking of this color change by potassium iodide (KI), composite (CMP) and glass ionomer cement (GI) and the effect of aging on this color masking effect. Methods: An in-vitro study in which 52 carious primary molars were collected, prepared, and distributed randomly into four groups equally as follows: Group A: SDF 38%; Group B: SDF 38% + KI; Group C: SDF 38% + CMP; Group D: SDF 38% + GI. Color changes were recorded for each sample at baseline, and after application of the tested materials. Moreover, all samples had undergone Suntest aging followed by a third color reading. CIELAB values L*, a*, b*, ΔL, Δa, and Δb were measured, ΔE was calculated, and data were analyzed using multivariate analysis of variance (MANOVA) and post-Hoc Scheffé test (p < 0.05). Results: MANOVA revealed the significant influence of the factor ‘material’. SDF caused an obvious color change compared to the color of carious dentin. Regarding ΔL, the color change of groups C and D was not significant directly after application of the tested materials. After aging, it was significant among all groups, including groups C and D. In Δa there was a difference between SDF and groups B and C after application of the tested materials, and aging produced the same results. The color shifts of Δb of all tested groups varied significantly from one another. After aging, there was no difference between group D and either group A or B. Conclusions: Treatment with SDF caused obvious discoloration of carious dentin. Directly after SDF application, all tested materials could effectively mask the color change associated with the application of SDF. CMP was the only material whose color masking effect was not completely reversed by aging

Influence of structured reporting of tooth-colored indirect restorations on clinical decision-making

The aim of the present study was to discover what influence structured reporting (study group = A) of toothcoloured lab-fabricated restorations has on clinical decision-making following international guidelines. By way of comparison, the conventional approach in the form of short reporting with 5 items (control group = B) was used as gold standard. The study was carried out in the first clinical semester of dentistry (n = 68) at the Goethe University in Frankfurt am Main. In the study group, indirect ceramic restorations were assessed on a scale of 1 (very good) to 5 (insufficient) using structured reporting (7 items, each with 5 subgroups) in accordance to World Dental Federation (FDI) - standards. Following this, the clinical decision on the insertion of the restoration was made. To evaluate the quality of the structured reporting, sensitivity, specificity, confidence intervals (Cl) and the respective predictive values (positive = PPV, negative= NPV) were determined. Based on FDI reporting, a ceramic inlay is also favored with a great degree of certainty in clinical decisions: this was the true in 34 procedures out of a total of 38 clinically incorporated ceramic inlays [sensitivity 67% (95% CI: 46%83%); specificity 89% (95% Cl: 75%-97%); PPV 82%, NPV 79%]. In the control group, sensitivity was 56% (95% CI: 35%-75%); specificity 92% (95% CI: 79%-98%); PPV 83%, NPV 74%. No significant differences could be determined between A and B (p = 0.813).&nbsp;Due to the higher sensitivity and efficiency given comparable specificity, structured reporting of tooth-coloured lab-fabricated restorations based on FDI criteria, appears more recommendable than short reporting. It is also suitable for promoting decision-making in quality assessment, thus improving the durability of dental restorations.</p

Evaluation of an interactive e-learning module “Toothache Clinic” for delivering information on dental pain: a prospective cohort study

This multivariate, prospective, monocentric, observational study evaluates the experimental application of an interactive e-learning module on the topic of dental pain, which deals with the content of interdisciplinary diagnostics and therapy of dental pain. The module (“Toothache Clinic”) was offered to dentistry students during the first, second and fourth clinical semesters. A total of n = 138 students took part.&nbsp;The questionnaire used in the study comprised 43 items (assigned to three domains) as well as questions on academic progress, gender, information technology (IT) background and module evaluation. The explorative factor analysis resulted in a reliability value (Cronbach’s Alpha) of 0.94. The results show a good rating for the module of 2.09 ± 0.55 (1 = excellent to 6 = unsatisfactory) across all groups. 94.17% of the volunteers would recommend the module to their fellow students. With a rating of 1.96 ± 0.51 (1 = excellent to 6 = unsatisfactory), women rated the module significantly better than men who rated it 2.27± 0.67 (p = 0.016). There were no significant differences in the ratings of the module between the three semesters. Furthermore, the results show no significant correlation between module assessment and prior information concerning technology education. In summary, it can be said that the students rated the e-learning module (“Toothache Clinic”) positively, regardless of their IT (information technology) knowledge and academic progress.&nbsp; Keywords: pain medicine, dental, e-learning, gender, education</p

Pain perception and functional/occlusal parameters in sleep bruxism subjects following a therapeutic intervention

Abstract Background This study was conducted to assess the individual pain perception in sleep bruxism (SB) subjects. Moreover, the effects of a cognitive behavioural therapy (CBT) compared to an occlusal appliance (OA) on pain perception and a possible continuative impact on several functional parameters were investigated. Methods A total of 57 SB subjects participated in this investigation. The diagnosis of SB was based on the clinical criteria of the American Academy of Sleep Medicine (AASM). Twenty-eight SB subjects were randomly allocated to the CBT group and 29 to the OA group. The therapeutic intervention took place over a period of 12 weeks, whereby both groups were examined at baseline, immediately after termination of the intervention, and at a 6-month follow-up for pain perception and functional parameters. At each of the three measurement periods, participants completed the pain perception scale and ten functional/occlusal parameters were recorded. Results Of the 12 parameters recorded, statistically significant main effects were found for the affective pain perception (p < 0.05) and for the three functional variables. Interestingly, the values obtained for the affective pain perception were considerably below that of a reference group. Apart from the determined statistically significant results, the values recorded for all functional/occlusal variables as well as those obtained for the sensory pain perception were clearly located within normative ranges. Conclusions Within the limitations of this study, it might be concluded that the significantly reduced affective pain perception in SB subjects is the expression of an adaptation mechanism

Dental training in evidence-based dentistry : a replication study

Background: In the area of education research, it is well-known that studies of a defi ned question are seldom replicated. Furthermore, e-learning resources with evidence-based content in dentistry have received relatively little attention from researchers. The Context and Purpose of the Study: The aim of this clinical study was to evaluate how dentistry students from two consecutive cohorts in their fi rst clinical semester rate a long-standing evidencebased dentistry (EbD) resource in an e-learning environment using a questionnaire of 43 specifi c items on 1) general questions regarding user-friendliness and acceptability, as well as 2) specifi c questions on content and functional range (A), handling and technical aspects (B), and didactics and educational value (C) based on a Likert scale from 0 = ‘strongly disagree’ to 3 = ‘strongly agree’, and how this compares to a primary study in which the resource was addressed as a novelty. The data were analyzed statistically using a one-way ANOVA followed by a Kruskal-Wallis multiple-comparison Z-test. Results: A response rate of 100% was achieved. The majority of the users thought the topic of EbD to be important. The e-learning resource was rated with a score of 2.40 ± 0.66 (on a Likert scale from 1-6 where 1 = "very good" and 6 = "insuffi cient"). 86.15% of the students stated that they consider the resource benefi cial for their study in clinical simulation and in patient treatment courses. The results averaged for A: 1.92 (±0.57; median: 1.928), B: 1.48 (±0.60), and C: 2.27 (±0.67). The obtained results in the replication study showed no statistical signifi cant differences to the primary study. Conclusions: The e-learning resource with dentistry vignettes cases and learning components on evidence-based principles was consistently rated positively by the students. Owing to their agreement with the data of the primary study, the results of the present study point to the remarkable validity of the method of evaluation. This should be addressed in future studies with larger cohorts