Romanian dental students' learning experience related to lifestyle changes imposed by Covid-19 lockdown.

Background and aim: The SARS-CoV-2 outbreak in Romania was followed by the declaration of an Emergency State and the subsequent lockdown. As all the schools and universities ceased onsite activities, the teaching process continued exclusively online, on different platforms, such as Microsoft Teams or Zoom. Objectives: The aim of this cross-sectional study is to evaluate how the lifestyle changes imposed by the Covid-19 lockdown and online lectures influenced the learning experience of Romanian dental students, as their point of view could bring new information which might contribute to improving the teaching process. Methods: The questionnaire had 28 items, each with either a Likert Scale or a multiple-choice option and was distributed in April 2020, one month after implementation of circulation restrictions and social distancing. Results: Compared to classical teaching, we found that the online teaching process had a lower efficiency, with a higher satisfaction level for online courses, but lower for online practical teaching activities. The absence of human interaction was found to be detrimental to the teaching process. Conclusion: Despite the lower efficiency of online learning, it was a good alternative that helped students continue their education in the situation created by the outbreak of Covid-19. For higher learning efficiency, a compromise method consisting of online courses and onsite practical training could be a better alternative.

Biomineralization ability of an experimental bioceramic endodontic sealer based on nanoparticles of calcium silicates.

Background and aims: The ultimate goal of endodontic therapy is to prevent periradicular disease or to promote the healing of the periradicular lesions. The use of nontoxic, biocompatible, and bioactive materials designed for root canal obturation is preferred due to their increased potential to induce healing and bone regeneration, thereby restoring the functionality of the tooth and the adjacent tissues. The aim of this study was to analyze the biomineralization ability of an experimental endodontic sealer based on synthesized nanoparticles of calcium silicates. Methods: Six plastic moulds were filled with the freshly prepared experimental endodontic sealer and kept for 3 days at room temperature in a moist environment. After hardening, four samples were subsequently immersed in simulated body fluid (SBF) and introduced in incubator at 37°C and 100% relative humidity; two of them were kept for 7 days and the other two for 14 days. Two samples were not immersed in SBF and were used for comparison. The biomineralization potential was assessed by XRPD, SEM and EDS analysis. Results: Following immersion in SBF, XRPD analysis identified apatite crystals for experimental material both after 7 and 14 days. SEM images displayed the specific microstructure for bioceramic materials alongside with the presence of apatite crystals on their surface. EDS identified the presence of phosphorus and calcium elements, underlining the biomineralization potential of the experimental material. Conclusion: Interaction between experimental material and SBF succeeded in inducing precipitation of apatite on its surface, evidenced by XRDP, SEM and EDS analysis.

Benefits of using magnification in dental specialties - a narrative review.

An increased number of clinicians are using magnification to facilitate their vision when carrying out dental examinations and treatments. The best instrument for this purpose is the microscope, which has proven to enhance quality, longevity and outcome of clinical work. Its use in some dental specialties (such as endodontics) is now well established, but there is also a role for this equipment in other branches of dentistry. To anticipate the contribution of magnification to dentistry in general, recent research and experimental data on the importance of magnification devices will be considered, from the perspectives of optical issues, diagnosing methods and treatment options. It will be shown that, while the microscope is vital to certain specialties (such as endodontics, periodontics, restorative dentistry and prosthodontics), it has little effect on others (orthodontics, for example). This synthesis of current researchattempts to shed light on the optimal magnification used in certain clinical situations, the distinctive benefits of loupes and microscopes for each dental branch, as well as their drawbacks.

In Vitro Evaluation of the Accuracy of Three Electronic Apex Locators Using Different Sodium Hypochlorite Concentrations.

Background and Objectives: The aim of this study was to compare the accuracy of three types of electronic apex locators (EALs) when two different concentrations of NaOCl irrigation solutions are used by two operators. Materials and Methods: After creating the access cavities for 20 single rooted extracted teeth, the actual canal length (ACL) of each canal was determined visually using a #10 file and magnification. The teeth were subsequently inserted in plastic molds filled with alginate. The electronic measurement of root canal length (EWL) was performed using three different electronic apex locators: Root ZX II, Apex ID, and Dual Pex. Two independent operators, an endodontic specialist with 20 years practice and an undergraduate student in the final year of study, performed the irrigation procedures with two different concentrations of NaOCl (2% and 5.25%), and then measured the EWL using each of the EALs. The accuracy of all EALs, was determined in each case by subtracting the EWL from the ACL. Statistical analyses were performed using one-way ANOVA test. Results: In the presence of 2% NaOCl solution, for a margin error of ±0.5 mm, Root ZX II, Apex ID, and Dual Pex presented an accuracy of 90%, 80%, and 85% respectively. The increase in the concentration of the irrigation solution affected the accuracy of Root ZX II and Apex ID for both operators, diminishing it to 75% for the same margin error, but improved Dual Pex's accuracy to 100%. Conclusions: The best accuracy in working length determination was obtained by Root ZX II for 2% NaOCl solution and by Dual Pex for 5.25% NaOCl solution with no significant statistical difference when compared.

Comparative microleakage outcomes of different techniques used for creating the occlusal anatomy in occlusal direct restorations using the dental operating microscope.

OBJECTIVES: Microleakage in direct dental restorations is a primary causal factor in the restoration's failure. The aim of this study was to evaluate whether the technique for occlusal layering of the composite resin (the use of brush adaptation, the use of magnification, cusp build-up, stamp technique) has any effect on microleakage of direct restorations in occlusal cavities. MATERIALS AND METHODS: One hundred extracted human molars were restored using five restoration techniques (Packable Bulk technique, Occlusal Stamp technique, Successive Cusp Build-up technique, Successive Cusp Build-up technique + Brush adaptation, Successive Cusp Build-up technique + brush adaptation + Dental Operative Microscope magnification). The teeth were subjected to thermal aging for 800 cycles at 5°C and 55°C, infiltrated with basic fuchsin dye for 24 h, and then sectioned buccolingually in the middle of the crown. Infiltration was measured in four areas of the tooth section by five different observers and then given a score from 1 to 3, proportional to infiltration depth. RESULTS: The lowest mean scores for infiltration (meaning less infiltration observed) were present in Group A (1.41 ± 0.878) and Group C (1.46 ± 0.679), while Group D showed the highest infiltration scores (1.75 ± 0.853). When comparing the groups for differences, no statistically significant difference in infiltration was found between any technique p < .586. CONCLUSION: The techniques examined for placing the occlusal layer of composite in direct restorations do not differ significantly in terms of marginal infiltration, although a slight improvement was found when using the bulk technique and the successive cusp build-up.

Effectiveness of Different Final Irrigation Procedures on Enterococcus faecalis Infected Root Canals: An In Vitro Evaluation.

This study aimed to evaluate the antibacterial effect of three final irrigation protocols and to compare their ability to remove the smear layer and debris from the root canal. Methods: Sixty-three single-rooted human teeth were inoculated with Enterococcus faecalis for 14 days. The teeth were divided into a positive control group (N = 3) and three treatment groups (N = 20) as follows: final irrigation with saline solution (control group), irrigation with 5.25% NaOCl ultrasonically activated with EndoUltra (EU), standard needle irrigation with Qmix 2in1 (Qx) and irrigation with 5.25% NaOCl activated using SiroLaser Blue (SB). The bacterial load was evaluated by analyzing the colony-forming units (CFU/mL). Selected specimens were split longitudinally and examined using scanning electron microscopy in order to determine the presence of a smear layer and debris. Statistical analyses were performed using one-way ANOVA and the Kruskal−Wallis rank-sum test. Results: Activation of NaOCl with EndoUltra or SiroLaser Blue was superior at reducing intracanal bacteria relative to standard needle irrigation with Qmix 2in1 solution (p < 0.05). Even though SiroLaser Blue showed the best results for removing the smear layer and debris, no significant differences were detected between the groups (p > 0.05). Conclusions: Final irrigation with 5.25% NaOCl ultrasonically activated using EndoUltra or SiroLaser Blue demonstrated a higher efficacy in bacterial reduction than standard needle irrigation with Qmix 2in1.

Evaluation of Bond Strength of Four Different Root Canal Sealers.

The purposes of the study were to evaluate the influence of the sealer's chemical composition on the interfacial strength between root canal dentin and root filling material, for two different classes of endodontic sealers, and to assess their failure modes. Methods: Forty extracted single-rooted teeth were randomly divided into four groups using the following endodontic sealers: RealSeal SE and Resilon (RSSE); EndoSequence BC sealer and BC Point (EBCS); Endoseal MTA and gutta-percha (EDS); Bioroot RCS and gutta-percha (BRS). Teeth were embedded in acrylic resin, and the roots were sectioned horizontally into 1 mm slices. For each slice, the perimeter was measured. A push-out test was performed using an Instron universal testing machine. For each sample, bond strength was calculated. Specimens were examined by SEM investigation in order to analyze the dentin−sealer−core interface. Results were assessed using analysis of variance (ANOVA) and Tukey and Bonferroni test. Results: Statistical analysis revealed that EDS and gutta-percha had significantly higher resistance to dislodgement compared to the other three groups (p < 0.05). EBCS and BC Point showed significantly greater push-out bond strength values compared to RSSE and Resilon (p < 0.05). Conclusions: Bioceramic endodontic sealers showed a higher bond strength to root dentin than methacrylate resin-based endodontic sealer.

Oral Health-Related Knowledge, Attitude and Practice among Patients in Rural Areas around Cluj-Napoca, Romania.

The intent of the KAP (knowledge, attitude, practices) survey is to collect information about a specific target group related to their knowledge, what they consider to be known, and what they do about a particular topic. The aim of this study was to identify the level of importance of oral health, especially the level of knowledge, attitude and practices of rural patients around Cluj-Napoca, Romania. MATERIAL AND METHODS: A questionnaire consisting of five parts was used, trying to assess the self-perception of oral health, knowledge and attitude towards oral health, dental hygiene practices and eating habits. A clinical examination was also performed in order to identify the number of missing teeth, the caries and the presence of calculus. RESULTS: The study revealed that most patients have an average and good self-perception of oral health, although three-quarters of them have calculus deposits, and about half of them have more than three carious lesions and at least one extracted tooth. There is also a discrepancy between declared knowledge of oral health, eating habits and dental practices. CONCLUSIONS: The basic knowledge of rural patients about oral health can be considered satisfactory, but the practices, unfortunately, do not reflect this knowledge.

Development of New Experimental Dental Enamel Resin Infiltrants-Synthesis and Characterization.

The aim of the present study was to obtain experimental infiltration materials, intended for the treatment of dental white spots, and to investigate them. Two series of infiltrants (P1-P6)/(P1F-P6F) were obtained, based on different monomer mixtures, without/with glass filler (with fluoride release ability). Each infiltrant from the second series contained the same amount of glass powder, and each infiltrant from the (P-PF) group contained the same resin composition. The characteristics of the experimental infiltrants were investigated by degree of conversion (DC), mechanical strength, water sorption (WS), and fluoride release, in addition to residual monomer for (P1F-P6F) infiltrants. The results were compared with those obtained for commercial Icon infiltrant. For the experimental infiltrants, without/with filler, the recorded DC was in the range of 58.27-89.70%/60.62-89.99%, compared with Icon (46.94%) 24 h after polymerization. The release of fluoride depends on the permeability of the polymer matrix, with respect to the water sorption, which may help to diffuse ions in the storage medium but which can also influence the release of residual monomers. The highest flexural strengths were recorded for the (TEGDMA/HEMA/Bis-GMA) infiltrants (133.94 ± 16.389 MPa/146.31 ± 7.032 MPa). The best experimental infiltrants were P2 and P2F (Bis-GMA/HEMA/TEGDMA).

The advantages of the dental operative microscope in restorative dentistry.

Magnification devices improve direct and indirect vision and precision being significantly higher in microscope use compared to the loupes. Dental loupes are the most commonly used devices for magnification, due to the more affordable prices and the ease of use without major changes in the working protocol and ergonomics. Loupes primary benefits reported refers to ergonomics and posture, restoration evaluation/detection and overall treatment quality. There are some disadvantages that limit the use of loupes among dentists: lack of fixed position (fine movements of the dentist's head disturb the image of the magnified operating field); the need to change the loupes to achieve different magnification. On the contrary, the use of a dental microscope require minimum adjustment and effort so as to reduce postural deviation while working. It has been more than 30 years since dental practitioners raised the issue of using dental operating microscopes (DOM) in restorative dentistry, identifying the benefits of magnification in diagnosis and treatment steps. The growth is evident in recent years, maybe because of the familiarity of dentists with dental microscopes which have already become implicit endowment for endodontic specialists. Fiber optic lighting is the key factor that complements the magnification offered by the microscope so that treatments can now be performed under increased safety conditions and in conditions of significantly higher quality than in the past. Since the beginning of the 2000s the principles of minimally invasive dentistry have been widely promoted in dentistry. These principles are major impetus for the use of microscope by dentists. Working with magnification leads dentists to be more conservative with dental tissues.

A micro-computed tomography study of morphological aspect of root canal instrumentation with ProTaper Next and One Shape New Generation in mandibular molars.

ProTaper Next (Dentsply Maillefer, Ballaigues, Switzerland) (PTN) and One Shape New Generation (MicroMéga, Besançon, France) (OSNG) belong to a relatively new generation of rotary nickel-titanium (NiTi) files. Scientists keep improving features of endodontic files in order to obtain anatomically shaped and cleaned root canals and avoid canal transportation, for a better outcome of the endodontic treatment. For the current study, the aim was to evaluate and assess the changes in root canal morphology after instrumentation with PTN and OSNG by using micro-computed tomography (CT). This high-tech resolution tomography allows a much more detailed analysis of the root canal anatomy and its transformation after rotary instrumentation. We have selected 10 mandibular molars; before and after canal preparation, the samples were distributed in two homogeneous groups (PTN and OSNG groups) and submitted to standardized radiographs and micro-CT (SkyScan1172, Kontich, Belgium). From the three-dimensional (3D) images obtained from the scanning, we were able to perform a two-dimensional (2D) (perimeter, area and roundness), respectively a 3D (volume, surface area, structure model index) analysis, before and after root canal instrumentation. Results did not revealed important statistical differences among the two groups in relation to the curvature and volume of the root canals before instrumentation; after rotary instrumentation, there was a substantially increase of volume and surface area for all the samples (p<0.05). The two types of instruments preserved the original canal path, maintaining a continuous, safe and adequate shape and taper of the root canals.

Shade Correspondence, Color, and Translucency Differences between Human Dentine and a CAD/CAM Hybrid Ceramic System.

OBJECTIVE: To determine the shade correspondence between human dentine and two versions of a CAD/CAM hybrid ceramic system and to investigate color and translucency differences between these materials. MATERIALS AND METHODS: Twenty-four samples of different shades and opacities were fabricated from Vita Enamic CAD/CAM ceramic blocks. Human dentine samples were obtained from 73 extracted maxillary teeth. Color coordinates of all samples were measured using VitaEasyshade spectrophotometer. The translucency parameter (TP) and ΔEab* and ΔE00 color differences, with respect to human dentine of anterior and posterior teeth, were calculated. RESULTS: Vita Enamic Translucent was the best match for anterior teeth (>90% of cases) while Vita Enamic T 3M2 was the best option for the dentine samples of posterior teeth in 78.8% ( ΔEab*) and 54.5% ( ΔE00) of the cases. The smallest differences in translucency ( ΔTP) with the dentine samples of anterior teeth were obtained for Vita Enamic T 3M2 (92.5%) and with those of posterior teeth for Vita Enamic HT 1M2 (45.4%). CONCLUSIONS: VITA Enamic Translucent is the best option as color match for both anterior and posterior teeth dentine. In terms of translucency, VITA Enamic Translucent closely matched anterior teeth dentine while for posterior teeth, VITA Enamic HT was the best option. CLINICAL SIGNIFICANCE: The results of the present study could help clinicians in their decision of choosing a specific shade and translucency for their anterior or posterior esthetic restorations with hybrid ceramics. (J Esthet Restor Dent 28:S46-S55, 2016).