Acta Stomatologica Croatica最新文献

Objective: Effective tools and methods are applied during root canal retreatment to eliminate root canal obturation materials and preserve the initial root canal anatomy. The present study compared the efficacy of Reciproc, Neoniti, ProTaper, and Hedstrom files in the retreatment of curved root canals.

Material and methods: In the present in vitro study, 100 root canals with 25‒45º curvatures were used. After the samples were initially prepared and examined by CBCT, the root canals were obturated with gutta-percha and randomly assigned to four groups (n=25). A retreatment was carried out in each group with NeoNiTi, ProTaper, Reciproc, and Hedstrom files. CBCT examinations were carried out again under the same conditions. The samples were evaluated at 3-, 6-, and 9-mm distances from the apex on the first and the second CBCT image for root canal transportation and remaining gutta-percha in the root canals. The time required for retreating each canal in each sample was recorded. One-way ANOVA and corresponding non-parametric tests were applied for data analysis.

Results: The root canal transportation in the NeoNiTi group was lower than that in the other groups and significantly different from the ProTaper group (P<0.05). There was a remaining gutta-percha after retreatments in all the four groups, which was not statistically significant (P>0.05).

Conclusion: Despite the fact that the NeoNiTi file produced less transportation than other file systems evaluated in the retreatment of curved root canals, all the files were very effective at the clinically acceptable levels.

Objectives: The aim of the study was to evaluate the attitude and perspectives of dental students of four Croatian universities towards online learning during the COVID-19 pandemic.

Material and methods: An anonymous internet-based survey was administered to undergraduate dental medicine students at the Universities of Zagreb, Rijeka, Split and Osijek. The 29-item questionnaire collected data on students' demographics, online learning organization and management, and perception of online classes.

Results: Five hundred and four participants (85.1% female) took part in the survey. The majority of the participants (63.5%) were from the University of Zagreb. 39.6% of students reported agreement regarding online learning satisfaction. Individual university satisfaction ratings on overall online learning were: Osijek 3.69, Zagreb 3.22, Split 3.05 and Rijeka 2.64. Most students considered that lectures (82.9%) and seminars (78.9%) could be successfully delivered in an online learning format. The online learning format cannot successfully deliver laboratory, preclinical, clinical practicals or clinical clerkship, as agreed by more than 80% of the total student sample. 60% of students consider online learning a valuable alternative to face-to-face instruction.

Conclusion: Online learning was highly praised for educational formats such as lectures and seminars, and was considered a useful substitute for conventional learning. Conventional practical courses cannot be substituted with online learning. Overall perspective about online learning was mixed among the students of four universities. The findings of the present study can serve to help individual universities address the shortcomings and reinforce the strengths of their OL programs.

Objectives: The aim of the study was to examine the impact of rapid high-intensity polymerization on water sorption and solubility of a new generation of bulk-fill composite materials.

Material and methods: Five materials were tested: a conventional composite Filtek Z250 (3M, St. Paul, USA) and four bulk-fill composites, Filtek One Bulk Fill (3M), Tetric PowerFill (Ivoclar Vivadent, Schaan, Liechtenstein), Tetric PowerFlow (Ivoclar Vivadent), SDR Plus (Dentsply, Konstanz, Germany). Composite specimens with a 9-mm diameter and a 2-mm height (n = 6) were polymerized with a high-intensity curing unit (Bluephase® PowerCure, Ivoclar Vivadent). The control group was polymerized for a total of 40 s on both sides (1193 mW / cm²) and 3s group for 3 s on one side (3053 mW/cm²). Water sorption and solubility were measured by ISO 4049 method up to 30 days of immersion. The results were statistically analyzed using one-way ANOVA with Tukey post-hoc correction. Different polymerization protocols for the same material were compared by t-test (p <0.05).

Results: The 3s polymerization protocol increased the solubility of all materials. Filtek One Bulk Fill showed the highest water sorption and solubility values, and Tetric PowerFlow proved to be a stable material with low values of tested parameters. During immersion, a saturation of specimens was achieved in low-viscosity bulk-fill composites within two weeks, while in other materials it was not achieved within 30 days, or more, following the immersion.

Conclusions: Rapid polymerization caused an increase in solubility, which could affect the biocompatibility of the investigated materials not intended for the 3s curing. SDR Plus and Filtek One Bulk Fill should not be polymerized with rapid high-intensity curing due to increased solubility that exceeds ISO 4049:2009 limits.

Objectives: Oral health in children is additionally burdened with the presence of dental fear and anxiety (DFA). These clinical psychologic entities in their progressive stages inevitably lead to avoidance of dental appointments, which makes prevention and therapy of oral diseases more difficult. Upon the onset of DFA in general, as one of the emotional outcomes of stress in a dental office, most children patients could define the specific stressors that were most intense for them, which could predict the presence of DFA.

Aim: To examine the predictors of DFA presence in 9-12-year-old children, and investigate how they could explain the DFA occurrence in study participants.

Material and methods: The sample consisted of 200 children aged from 9 to 12 years. The DFA presence was determined by the modified version of the CFSS-DS scale. The child's behavior in the dental office during the treatment was evaluated by the trained observer using Venham anxiety and behavior rating scales. Socioeconomic status, characteristics of dental office visits, and previous caries experience were also analyzed.

Results: The main DFA predictors were related to invasive dental treatments, where the behavior during dental treatment was the most accurate expression of the DFA appearance.

Conclusions: Invasive dental procedures are the main stressful factor for DFA occurrence. Predisposing factors could strengthen the DFA occurrence.

Background: The Dunning-Kruger effect (cognitive bias) is a psychological phenomenon that implies that individuals with a lack of knowledge and skills have an unrealistically optimistic image of their abilities compared to others.

Purpose: The study aimed to examine the presence of the Dunning-Kruger effect in fifth (final) year dental undergraduate students at Gulf Medical University, UAE, in clinical domains related to pediatric dentistry.

Methods: A longitudinal cohort study was conducted at Gulf Medical University, College of Dentistry, to evaluate cognitive bias among 5th-year dental students at GMU in the competency domains of communication, diagnosis, and clinical skills in Pediatric dentistry.

Results: Overall, compared to the level of confidence of students in September, there was a decline in the level of confidence in January. With an increase in time, the percentage shifted to a higher level in May across all domains.

Conclusion: Characteristic patterns of fluctuations in students' self-confidence during clinical exposure are observed. The research results prove that the Dunning-Kruger effect, the cognitive bias of the perception pattern, is present in the examined group of dental students.

Introduction: Over the last decade, the criminal justice system among the European countries deals with a new group of people, the undocumented people. In the criminal field, most of the suspected claimed to be under the minor legal age according to the type of crime. The government of each European country is committed to protecting the children and vulnerable people. There are serious safety concerns since adults falsely claim to be minors and legal systems oppose to such claims. In this study, we have used different age assessment methods and some of them without accuracy.

Objective: To meet the general considerations we developed a study using the current dental age assessment methods. Hence, for the Portuguese population, this study aims to validate the European regression formula between the ages of 6 and 15 years of age; to estimate the cut-off point for the age of 12 years, and to compare the quantitative approach of European regression formula with Demirjian's qualitative approach for age estimation.

Material and methods: 483 orthopantomograms were analysed using the European formula and Demirjian scoring stages. A new method, Model 2, was designed to better suit the Portuguese population.

Results: The European formula: average age underestimation of 4.88 for the third quadrant and 4.04 months for the fourth quadrant; and a mean absolute error (MAE) of 10.93 and 10.68 months respectively. Demirjian method: average overestimation of 8.70 months, MAE of 12.85 months. In Model 2: MAE of 9.37 months for the third quadrant, and 9.28 months for the fourth quadrant. Both European formula and Demirjian method had an area under ROC curves results above 0.93. Discrepancy of sensitivity between methods for the specific cut-off point: 11.48. The results obtained in this study can be extrapolated to 87.33% of the Portuguese population.

Conclusions: The European regression formula can be applied for the Portuguese population, and seems to be more accurate than Demirjian's methodology in this population. Nevertheless, both European regression formula and Demirjian method present similarly suitable results in the classification of 12 years of age, although there is a noticeable discrepancy favouring the European regression formula. The European Formula when applied for criminal age assessment, independently of population, is mandatory to indicate to the judicial institutions, the sensitivity of the results.

Background: The dental ceramic materials are constantly being developed due to their continuous clinical application in the field of esthetic dentistry. Glass ceramics (GC) materials are also of special interest for dental application due to their specific properties; and thus, they can be applied as crowns, veneers and small bridges.

Purpose: However, due to a variety of different GC materials, it is of keen interest to inspect their morphology and ion-diffusion, which also governs aging properties.

Material and methods: In this study, two different GC materials were processed, i.e., lithium silicate (LS-10) and lithium disilicate (LS-20). The aforementioned properties can be inspected by using impedance spectroscopy (IS) and scanning electron microscopy (SEM).

Results: SEM study suggested that LS-10 material is harder to mechanically process by computer-aided design/computer-aided manufacturing (CAD/CAM) technology. Furthermore, IS measurements showed that LS-20 (vs. LS-10) has more pronounced resistance properties.

Conclusion: According to IS data, it was concluded that LS-20 (vs. LS-10) has more pronounced resistance properties that point out to hindered ion-diffusion and to better aging properties.

Diagnosing child abuse still poses a challenge for healthcare professionals. We will present a case in which a physically and emotionally abused four-year-old boy had an undiagnosed lower jaw fracture for almost eight months. The child first presented with a peri-mandibular swelling and was treated with antibiotics prescribed by his doctor of dental medicine. After not having responded to antibiotic treatment, the boy was referred to the Department of Oral and Maxillofacial Surgery, accompanied by his birth mother. The deciduous mandibular molars with deep cavities were extracted since we thought that they were the reason for swelling. After several visits with his foster mother, the child was finally diagnosed with a lower jaw fracture and a psychosomatic disorder. Physical abuse by his birth parents was later on confirmed, and the consequences were insufficient growth, non-perception of pain and reduced speech development. After having been with his foster mother for almost a year, the child learned to complain when he was in pain. This report emphasizes the importance of taking a detailed medical history along with a thorough clinical examination.

Objectives: Although titanium-based implants are considered bioinert, it has been found that they are subject to corrosion and wear. This study aimed to evaluate the cytotoxic and genotoxic potential of two implant systems in gingival epithelial cells.

Material and methods: Gingival swabs were taken three times from 91 subjects. The first swab was taken before dental implant placement, the second swab 90 days after dental implant placement and the third swab 21 days following the healing abutment placement. DNA damage was analyzed using the micronucleus test. Tested dental implants with corresponding healing abutments were Ankylos and Dentium SuperLine.

Results: Of all scored forms of cytogenetic damage in gingival cells of individuals after implementation of tested dental implant systems, only an increase in the number of binucleated cells (P ≤ 0.001) was significant in contrast to control values for both tested implant systems, 90 days after dental implant placement and 21 days following the healing abutment placement.

Conclusion: It may be concluded that there are no titanium-based implant dependent cytogenetic damage in gingival epithelial cells. A slight increase in cytogenetic damage has been observed but it is of no biological relevance and might be associated with healing abutment induced effect.

Objective: The present clinical trial was conducted to evaluate the clinical performance of the biomimetic, bilayered structure utilizing a fiber reinforced bulk fill resin composite with a nanohybrid capping layer, compared to incremental packing of nanohybrid resin composite, in deep proximal cavities in permanent molars.

Material and methods: A total of 36 deep proximal cavities in vital molars were restored either with a bilayered structure of fiber reinforced composite resin as a dentine substitute and a capping layer of nanohybrid composite resin (n=18) or conventional, nanohybrid composite resin incrementation (n=18). The restorations were assessed over a period of 12 months using the modified USPHS criteria. The criteria evaluated were: fracture and retention, marginal integrity, marginal discoloration, anatomic form, proximal contact, surface texture, radiographic evaluation, postoperative sensitivity and secondary caries.

Results: There was no statistically or clinically significant difference between fiber-reinforced resin composite and conventional incremental resin composite. There was no risk for failure regarding all the evaluated modified USPHS criteria for both materials after 12 months (RR= 1(95% CI 0.0209 to 47.8503; P =1.0000)).

Conclusion: The biomimetic approach utilizing a fiber reinforced resin composite dentine substitute showed a comparable clinical performance to nanohybrid resin composite incrementation. Bulk fill fiber reinforced resin composite is an efficient alternative in restoration of deep proximal cavities in posterior teeth. Further long-term studies are necessary to confirm these results.