Journal of Dental Medicine

Background and Aims: In endodontically treated teeth, the fiber posts are used to retain a core restoration. The purpose of this study was to evaluate the effect of different resin cements on the bond strength of fiber reinforced composite posts to root canal dentin, and comparing the bond strength in different sections of root.
Materials and Methods: In this in-vitro experimental study, 48 extracted single-canal central incisors were endodontically treated. For the push out test, the posts were divided into 3 groups according to one of the following three different cement materials (n=16) (Bifix SE, Bifix QM, Rebilda). Three slices with a thickness of 2-mm were prepared of each root. The push-out tests were performed at a cross-head speed of 1 mm/minute using a universal testing machine. Data were analyzed by two-way and one-way ANOVA test followed by Tukey post hoc test (α=0.05).
Results: There was no significant differences between the mean push out bond strength of three experimental groups (P=0.650), but there were significant differences between the mean push out bond strength of root dentin regions (P<0.001).
Conclusion: Under the conditions of this study, there was no significant difference between the mean push out bond strength of 3 different resin cement systems. The coronal region of root dentin showed significantly higher mean bond strength values than that of the middle and apical thirds.

Background and Aims: Finishing and polishing of composites is a critical step influencing the clinical service of restorations. The aim of this article was to evaluate and compare the effect of two liquid polishes on the polish retention of two nanocomposites.
Materials and Methods: Eighty standardized disk-shaped specimens (4×2 mm) were prepared from two nanocomposites (n=40), including one nano-filled composite (Filtek Z350 XT-3M ESPE, USA) and one nano-hybrid composite (Aelite Aesthetic Enamel-Bisco, Inc. Schaumburg, USA). The specimens were randomly divided into 4 subgroups (n=10) based on the method of finishing (F) and polishing (P) procedures: M: as control, polymerized under Mylar strip; S: finish and polish with a sequence of Sof-Lex discs (3M ESPE, USA); SP: finish and polish with Sof-Lex discs and use of Permaseal liquid polish (Ultradent products, Inc. USA); SB: finish and polish with Sof-Lex discs and use of Biscover liquid polish (Bisco, Inc. Schaumburg, USA). The specimens were undergone pH cycling and brushing machine and then, the average surface roughness (Ra) and average profile changes along the desired area (Rz) of the specimens were determined with profilometer instrument. Two-way and one-way analysis of variance (ANOVA) was used to compare the mean of surface roughness. Then, Tukey test was used to identify the groups responsible for the difference and t-test was used to compare the mean of surface roughness.
Results: The type of composite and the method of polishing procedure had no effect on the mean Ra (P=0.733) but it had significant effect on Rz1 factor (P=0.025).
Conclusion: Using liquid polish after polishing discs had no effect on the polish retention of nanocomposites.

Background and Aims: Oral health affects the quality of life and plays the main role in achieving optimal conditions of health and general well-being. Therefore, this study was conducted with the aim of investigating the psychosocial effects and quality of life related to oral health in patients treated with composite veneers.
Materials and Methods: In this cross-sectional study, 48 patients who referred to the restorative department of Jundishapur University of Ahvaz for composite veneer treatment were participated. The PIDAQ questionnaire was used to investigate the aesthetic effects of composite veneer treatment on the psychosocial conditions of the patients, and the OHIP-14 questionnaire was used to investigate the quality of life related to oral health. Patients were asked to complete both questionnaires before treatment and one month after composite veneer treatment. Also, demographic information including age, sex, education and marital status of the patients were recorded. The purpose and benefits of participating in this study were fully explained to the patients and the patients voluntarily participated in this study. Then, an informed consent form was given to the patients. In order to compare the scores before and after the treatment, the paired T-test and its non-parametric equation expression (Will-Coxon) were used, and P<0.05 was considered.
Results: According to the results, the average age of the respondents was 28 years. In terms of gender, 54.2% of the patients were male, and in terms of education, most of the participants in the study had a bachelor's degree (35.4%). The total score of OHIP-14 before treatment was 26 and after treatment 22. Also, the total score of PIDAQ before treatment was 49 and after treatment 28. Comparing the scores of psychosocial effects and quality of life related to the oral health before and after composite veneer treatment showed that there was a difference between the average score of psychosocial effects and quality of life. There was a significant difference related to the oral health before and after composite veneer treatment, which significantly decreased after treatment (P<0.05).
Conclusion: The present study showed that suitable veneer composite treatments could improve the oral health related to the quality of life of people. Also, treatment with composite veneers could have a significant effect on patients' self-confidence. Composite veneers could reduce social effects, psychological effects, and cosmetic concerns related to patients’ teeth.

Background and Aims: Repairing existing composite restorations, rather than replacing them entirely, is regarded as a conservative and tissue-preserving approach in restorative dentistry. However, achieving a durable bond between the aged and newly applied composite resin remains a significant clinical challenge. This study aimed to compare the shear bond strength of repaired composite restorations using three different adhesive systems.
Materials and Methods: In this in vitro study, which conducted at the Faculty of Dentistry, Urmia University of Medical Sciences, 60 disk-shaped composite specimens were fabricated with standard dimensions. After undergoing artificial aging (storage in distilled water for 6 months), their surfaces were roughened mechanically using a diamond bur. The specimens were randomly divided into three groups (n=20) and repaired using fifth-generation (Adper Single Bond), seventh-generation (OptiBond All-In-One), and universal (Single Bond Universal) adhesives, followed by the application of new composite. All  specimens were subjected to thermocycling, and the shear bond strength was measured using a universal testing machine. Fracture patterns of the samples were also examined using a stereomicroscope to determine the modes of failure. Data were analyzed using one-way ANOVA and Chi-square tests in SPSS at a significance level of 0.05.
Results: The mean shear bond strengths were 15.22 ± 4.47 MPa for Adper Single Bond, 14.05 ± 4.66 MPa for OptiBond All-In-One, and 13.44 ± 4.68 MPa for Single Bond Universal. No statistically significant differences were found among the groups (P=0.468). Fracture pattern distribution was also not significantly different (P=0.453), with predominantly cohesive or mixed failures observed across all groups. No adhesive failures were observed.
Conclusion: Under standardized surface preparation, none of the tested adhesive systems demonstrated a statistically significant advantage in the shear bond strength between the aged and new composite. Therefore, the choice of adhesive in composite repair procedures can be guided by practical considerations such as product availability, ease of application, and dentist preference.