Objectives: The aim of this study is to evaluate the efficacy of dentin bonding agent (DBA) in preventing coronal discoloration caused by four different root canal sealers- MTA Fillapex, Sealapex, Zical and Z. O. B seal at different time intervals by measuring chromatic alterations using digital images analysis method.
Methodology: Ninety mandibular premolars were collected and sectioned at 1 mm below the cementoenamel junction. Standard access cavity preparations of dimensions (depth-3 mm, width-0.8 mm, and length-3 mm) were prepared with a No. 245 bur through the cervical access. Following the standard irrigation protocol, specimens were then randomly divided into nine groups (four groups without DBA [1-4] +4 groups with DBA [5-8] +1 negative control [9]). In Groups 1-4, four different root canal sealers (MTA Fillapex, Sealapex, Zical, and Z.O.B seal) were applied to the walls of the pulp chamber. For Groups 5-8, the samples were etched with 37% phosphoric acid and DBA application was done before the respective root canal sealer application. The cervical access in all specimens was sealed using glass ionomer cement. Digital photographs were taken under standard lighting and environmental conditions at different time intervals: preprocedural, postprocedural, and after 1, 2, 3, and 4 months. These images were analyzed using Adobe Photoshop CS6 from which laboratory values and subsequently Delta E values were obtained.
Results: Statistical analysis performed using repeated measures ANOVA and post hoc Tukey's tests show that the groups with DBA application had significantly lower mean Delta E values (P < 0.05) compared to the groups without DBA application.
Conclusion: DBAs applied to the dentinal walls of the pulp chamber before obturation can effectively reduce the sealer-induced coronal discoloration.
AIM: To evaluate the fracture resistance and failure pattern of three different cavity designs restored with monolithic zirconia.
MATERIALS AND METHODS: Human maxillary premolars atraumatically extracted for orthodontic reasons were chosen. A total of 40 teeth were selected and divided into four groups (n=10). Group I-Sound teeth (control with no preparation). Group II-MOD Inlay, Group III-Partial Onlay, Group IV-Complete Onlay. Restorations were fabricated with monolithic partially sintered zirconia CAD (SAGEMAX- NexxZr). All the 30 samples were cemented using Multilink Automix (Ivoclar) and subjected to fracture resistance testing using Universal Testing Machine (UTM) (Instron) with a steel ball of 3.5 mm diameter at crosshead speed of 0.5 mm/minute. Stereomicroscope was used to evaluate the modes of failure of the fractured specimen. Fracture resistance was tested using parametric one way ANOVA test, unpaired t-test and Tukey test. Fracture patterns were assessed using non-parametric Chi-square test.
RESULTS: Group IV (Complete Onlay) presented highest fracture resistance and showed statistical significant difference. Group II (MOD Inlay) and Group III (Partial Onlay) showed significantly lower values than the Group I (Sound teeth). However, Groups I, II and III presented no significant difference from each other. Coming to the modes of failure, Group II (MOD Inlay) and Group III (Partial Onlay) presented mixed type of failures; Group IV (Complete Onlay) demonstrated 70% Type I failures.
CONCLUSION: Of the three cavity designs evaluated, Complete Onlay had shown a significant increase in the fracture resistance than the Sound teeth.
METHODS: To this end, we evaluated the quantitative characteristics of top cited articles in the fields with a total citation (≥50) in the Web of Science (WoS) database. Using one-way independent ANOVA, data extracted spanning a period of 1980-2015 were analyzed, while the non-parametric data analysis uses Kruskal-Walis test.
RESULTS: Articles with 11 to 20 pages attract more citations followed by those within the range of zero to 10. Articles with upward 21 pages are the least cited. Surprisingly, articles with more than two authors are significantly (P<0.05) less cited and the citation decreases as the number of authors increased.
CONCLUSION: Collaborative studies enjoy wider utilization and more citation, yet discounted merit of additional pages and limited collaborative research in disability field is revealed in this study.
METHOD: The study applied a quantitative approach based on the cross-sectional survey design and multistage cluster random sampling. A total of 400 women aged 35-69 years, were surveyed at 4 obstetric and gynecologic clinics affiliated to Tehran University of Medical Sciences in Tehran: the participation levels of 86 women who have had a mammogram were analyzed based on their self-efficacy, belief, social influence, and barriers concerning mammography utilization.
RESULTS: Consistent with the study framework, in bivariate analysis, the higher level of women's participation in breast cancer prevention programs was significantly related to more positive belief about mammography (p< .05), greater social influence on mammography (p< .01) and fewer barriers to mammography (p< .01). Self efficacy (p= .114) was not significantly related to the higher level of participation.
CONCLUSION: Results suggest that women's participation levels in breast cancer prevention programs might be associated with the specific psychosocial factors on breast cancer preventive behavior such as mammography screening.