Islamic Azad University Dental Branch Journal of Research in Dental and Maxillofacial Sciences 2588-4166 10 3 2025 9 1 Comparison of Remaining Dentin Thickness, Canal Transportation, and Canal Centering Ratio Using Three Different Rotary File Systems: A Cone-Beam Computed Tomography Analysis 168 175 EN Poulomi Guha Postgraduate Resident, Department of Conservative Dentistry and Endodontics, Saveetha Dental College and Hospitals, Saveetha Institute of Medical and Technical Science (SIMATS) Saveetha University, Chennai, India. Delphine Priscilla Antony Department of Conservative Dentistry and Endodontics, Saveetha Dental College and Hospitals, Saveetha Institute of Medical and Technical Science (SIMATS) Saveetha University, Chennai, India. Pradeep Solete Department of Conservative Dentistry and Endodontics, Saveetha Dental College and Hospitals, Saveetha Institute of Medical and Technical Science (SIMATS) Saveetha University, Chennai, India. Nishitha Arun Department of Conservative Dentistry and Endodontics, Saveetha Dental College and Hospitals, Saveetha Institute of Medical and Technical Science (SIMATS) Saveetha University, Chennai, India. Background and Aim: This study evaluated the remaining dentin thickness (RDT), canal transportation (CT), and canal centering ratio (CCR) of three different rotary file systems using cone-beam computed tomography (CBCT).    Materials and Methods: In this in vitro study, 153 extracted mandibular molars were evaluated. The working length was determined using CBCT before starting the experiment. A skilled dentist then prepared the root canals using three types of rotary files: ProFit S3, HyFLEX CM, and NeoEndo S. Pre- and post-treatment CBCT scans were analyzed to compare the results. One-way ANOVA and Tukey test were used for statistical analysis.    Results: ProFit S3 demonstrated a superior performance in preserving dentin thickness and maintaining canal geometry compared to HyFlex CM and NeoEndo S. In both MB and ML canals, at 6 mm and 9 mm, ProFit S3 exhibited significantly higher RDT (P≤0.007), less CT (P≤0.006), and better CCR (P≤0.01) than other systems. Among the remaining systems, HyFlex CM performed better than NeoEndo S for RDT and CT at these levels. At 3 mm, no significant differences were found for RDT or CT; however, ProFit S3 showed significantly better CCR than NeoEndo S (P<0.01) and HyFlex CM (P<0.05). Conclusion: Among the tested systems, ProFit S3 resulted in the least change in canal volume, suggesting that it may be better at preserving the original shape of the root canal, as well as the surrounding dentin, compared to Hyflex CM and NeoEndo S.  

Islamic Azad University Dental Branch Journal of Research in Dental and Maxillofacial Sciences 2588-4166 10 3 2025 9 1 Comparative Evaluation of Frictional Forces Between a Domestically Produced Orthodontic Bracket and a Well-Established Equivalent During Sliding Mechanics: An In Vitro Study 176 183 EN Nazanin Foroozandehfar Research Institute for Dental Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran. Shiva Tavakol Davani Department of Orthodontics, School of Dentistry, Shahid Beheshti University of Medical Sciences, Tehran, Iran. Azita Tehranchi Department of Orthodontics, School of Dentistry, Shahid Beheshti University of Medical Sciences, Tehran, Iran. Parisa Amjadi Department of Orthodontics, School of Dentistry, Shahid Beheshti University of Medical Sciences, Tehran, Iran. Hoori Mirmohammad Sadeghi Department of Orthodontics, School of Dentistry, Shahid Beheshti University of Medical Sciences, Tehran, Iran. Alireza Akbarzadeh Baghban Department of Basic Sciences, School of Rehabilitation Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran. Background and Aim: This in vitro study aimed to evaluate the static and kinetic frictional forces of domestically produced Emerald™ brackets during sliding mechanics and compare them with Mini Master™ brackets, a well-recognized alternative, to determine their viability as a cost-effective and reliable option.    Materials and Methods: For sample selection, 100 brackets from each manufacturer (200 in total) were screened under a light microscope, and then 34 Emerald™ and 34 Mini Master™ brackets were randomly selected. Additionally, 68 rectangular stainless-steel archwires (0.019” ×0.025”) were selected after eligibility assessment. Brackets were mounted on plastic blocks using cyanoacrylate adhesive, and archwires were secured in the bracket slots with elastic ligatures. Friction was measured using a universal testing machine (500-N load cell), with 5 mm/min speed over a 5 mm distance. The Shapiro-Wilk test assessed normality, and the Mann-Whitney U test compared friction between the groups (α = 0.05).    Results: No statistically significant difference was found between the mean kinetic frictional forces of Emerald™ (1.80±0.57 N) and Mini Master™ brackets (1.90±0.29 N) (P=0.342). However, Emerald™ brackets demonstrated significantly lower mean static frictional forces (2.14±0.76 N) compared to Mini Master™ group (2.44±0.41 N) (P=0.045). Additionally, Emerald™ brackets showed greater variability in friction values, with a wider range between minimum and maximum forces than the Mini Master™ group. Conclusion: The results suggest that Emerald™ brackets may provide a low-friction advantage, but their variable friction values require further research to evaluate clinical implications.  

Islamic Azad University Dental Branch Journal of Research in Dental and Maxillofacial Sciences 2588-4166 10 3 2025 9 1 Fracture Resistance of Unsupported Enamel Reinforced by Glass Fiber Ribbon 184 191 EN Golnaz Abbaspour Dentist, Private Practice, Tehran, Iran. Negin Barzegar Reyhani Dentist, Private Practice, Tehran, Iran. Shadab Safarzadeh Khosroshahi Department of Restorative Dentistry, TeMS.C., Islamic Azad University, Tehran, Iran. Shahriar Jalalian Department of Restorative Dentistry, Member of Dental Material Research Center, TeMS.C., Islamic Azad University, Tehran, Iran. Background and Aim: Fiber-reinforced composite (FRC) restoration is a relatively new method used to enhance the durability of composite restorations. This study measured the fracture resistance of unsupported enamel in composite restorations reinforced with fiber ribbon in comparison with conventional composite restorations.    Materials and Methods: In this in vitro study, 30 freshly extracted sound premolars were randomly divided into three groups (n=10): (I) control group: intact teeth, (II) mesio-occluso-distal (MOD) preparation followed by restoration with Filtek P60 composite, and (III) deep MOD preparation and cusp reduction, followed by reinforcement with Interlig fiber ribbon, and subsequent restoration and cusp coverage with Filtek P60 composite. The teeth were stored in saline for one week. Next, their fracture resistance was measured by a universal testing machine. The load at fracture was recorded in Newtons (N). One-way ANOVA followed by the Tamhane post-hoc test was used to compare the groups (alpha=0.05).    Results: Fracture resistance of enamel in both experimental groups was significantly reduced compared to intact teeth (P<0.05). Fracture resistance of enamel in FRC restorations was significantly higher compared to the conventional composite restorations (P<0.05). Conclusion: FRC restorations significantly increased the fracture resistance of unsupported enamel compared to the conventional composite restorations under in vitro settings.

Islamic Azad University Dental Branch Journal of Research in Dental and Maxillofacial Sciences 2588-4166 10 3 2025 9 1 Correlation between 3-Dimensional Volumetric Digital Analysis and Direct Technique for Periodontal Phenotype Assessment 192 202 EN Sruthima Gottumukkala Department of Periodontics and Implantology, Vishnu Dental College Poornima chittabathina Department of Periodontics and Implantology, Vishnu Dental College Gautami S Penmetsa Department of Periodontics and Implantology, Vishnu Dental College M Satyanarayana Raju Department of Prosthodontics and Implantology, Vishnu Dental College KSV Ramesh Department of Periodontics and Implantology, Vishnu Dental College Mohan Kumar Department of Periodontics and Implantology, Vishnu Dental College Anil Kumar Department of Periodontics and Implantology, Vishnu Dental College Murali Krishna Kumar Background and Aim: Several methods have been used to evaluate gingival thickness (GT); the most often used is the direct technique (DT), which is invasive. Thus, it is necessary to find a novel, reliable, and non-invasive approach for this purpose. This study aimed to evaluate the accuracy of assessment of periodontal phenotype using 3-dimensional digital analysis (digital technique) in comparison with the DT.    Materials and Methods: This cross-sectional study included 30 periodontally healthy participants between 20 and 25 years. One calibrated examiner performed all the measurements. GT and bone thickness (BT) were evaluated at 2 mm (GT2, BT2) and 4 mm (GT4, BT4) apical to the alveolar bone crest around 6 teeth i.e., one molar, one premolar and one incisor in each arch. In the DT, transgingival probing was performed using an endodontic file and a digital vernier caliper. In the digital technique, the DICOM data of cone-beam computed tomography (CBCT) and stereolithography (STL) data were superimposed to perform a digital analysis. Statistical analyses were conducted using the Student's t-test and Pearson’s correlation coefficient (alpha=0.05).    Results: Tooth-wise comparison of GT2, GT4, BT2, and BT4 measurements between the DT and digital technique groups showed very high correlation (r=0.86) for all the included teeth. The GT and BT measurements also showed very high correlation (r>0.8) between the two techniques. Conclusion: The results showed that digital measurement with STL-DICOM file superimposition was a reliable and reproducible technique comparable to the DT with an endodontic file.  

Islamic Azad University Dental Branch Journal of Research in Dental and Maxillofacial Sciences 2588-4166 10 3 2025 9 1 Effects of GLUMA Desensitizer and 810 nm Low-Level Diode Laser on Retention of Porcelain-Fused-to-Metal Frameworks Cemented with a Self-Adhesive Resin Cement 203 209 EN Marzieh Hajian Berenjestanaki Dentist, private practice. Arash Azizi Department of Oral Medicine, TeMS.C., Islamic Azad University, Tehran, Iran. Sahel Bazarnoei Faculty of Dentistry, Tehran Medical Sciences, Islamic Azad University, Tehran, Iran. Shirin Lawaf Department of Prosthodontics, TeMS.C., Islamic Azad University, Tehran, Iran. Background and Aim: Dentinal tubules are exposed to the oral environment during preparation of vital teeth for crown restorations, and patients show signs of tooth hypersensitivity. Some treatments have been suggested for dentin hypersensitivity after tooth preparation, such as diode laser (810 nm) irradiation and GLUMA desensitizer. This study aimed to assess the effects of 810 nm diode laser and GLUMA desensitizer on retention of porcelain-fused-to-metal (PFM) frameworks cemented with a self-adhesive resin cement.    Materials and Methods: This in vitro study evaluated 30 intact maxillary first premolars. After tooth preparation with a 0.5 to 0.7 mm finish line above the cementoenamel junction, full metal crowns were cast with a 5 mm diameter ring on their occlusal surface. The specimens were then divided into 3 groups (n=10) of control, 810 nm diode laser, and GLUMA desensitizer. The frameworks were cemented with RelyX U200 self-adhesive resin cement, and their retention was measured by a universal testing machine. Data were analyzed by ANOVA and Tukey post-hoc test (alpha=0.05).    Results: There was no significant difference in retention between 810 nm diode laser (134.96±37.50 N) and the control (138.17±40.81 N) group (P=0.986). However, framework retention in GLUMA desensitizer group (318.59±56.31 N) was significantly higher than that in other groups (P<0.05). Conclusion: In this in vitro study, GLUMA desensitizer had a significant positive effect while 810 nm diode laser irradiation did no not have any significant effect on retention of PFM frameworks cemented by RelyX U200 self-adhesive resin cement.  

Islamic Azad University Dental Branch Journal of Research in Dental and Maxillofacial Sciences 2588-4166 10 3 2025 9 1 Comparison of Water Sorption of Three Provisional Crown and Bridge Materials: An In Vitro Study 210 217 EN Gholamreza Esfahanizadeh Department of Prosthodontics, Faculty of Dentistry, Tehran Medical Sciences, Islamic Azad University, Tehran, Iran. Farzan Younesi Department of Prosthodontics, Faculty of Dentistry, Tehran Medical Sciences, Islamic Azad University, Tehran, Iran. Mohammadreza Hosseini kordkheili Department of Prosthodontics, Faculty of Dentistry, Tehran Medical Sciences, Islamic Azad University, Tehran, Iran. Hosein Akbari DDS, Private Practice, Tehran, Iran. Background and Aim: Water sorption of provisional crown materials decreases their mechanical properties and longevity, depending on the material type. This study aimed to compare the water sorption of three provisional crown materials in vitro.    Materials and Methods: In this in vitro experimental study, 14 disc-shaped specimens measuring 1 x 15 mm were fabricated from Telio CAD polymethyl methacrylate (PMMA) computer-aided design-computer-aided manufacturing (CAD-CAM) block (Ivoclar Vivadent), self-cure PMMA acrylic resin (Tempron GC), and ProviTemp K acrylic-based composite resin (Provi Temp K). The specimens were randomly coded and their weight (with 0.0001 g accuracy) and volume (with 0.001 mm accuracy) were measured. The water sorption of the specimens was calculated after 7 and 30 days. One-way ANOVA was applied for data analysis (α=0.05).    Results: On day 7, the highest water sorption was noted in Bisco acrylic-based composite resin (mean: 22.84±5.04 µg/mm3) and the lowest water sorption was recorded in PMMA CAD-CAM block (mean: 14.22±3.23 µg/mm3) (P=0.023). At 30 days, the highest water sorption was recorded in Tempron GC self-cure acrylic resin (mean: 48.53±18.44 µg/mm3) and the lowest water sorption was noted in PMMA CAD-CAM block (mean: 40.24±5.33 µg/mm3) (P=0.002). Conclusion: The water sorption of Bisco acrylic-based composite resin and Tempron GC self-cure acrylic resin was very high in the short-term. However, after 30 days, the water sorption of Bisco acrylic-based composite resin and PMMA CAD-CAM block was the same.  It appears that all three tested materials can provide acceptable clinical performance for the fabrication of provisional restorations.  

Islamic Azad University Dental Branch Journal of Research in Dental and Maxillofacial Sciences 2588-4166 10 3 2025 9 1 Effects of Bleaching on Surface Roughness and Color of Two Types of Composite Resins Subjected to Two Surface Polishing Methods 218 227 EN Marzieh Rohaninasab Department of Operative Dentistry, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran. Sedigheh Sadat Hashemi Kamangar Department of Operative Dentistry, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran. Zahra Govahi Dental Student, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran. Atoosa Nobakht Dental Student, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran. Background and Aim: This study aimed to evaluate the effects of bleaching on surface roughness and color of two types of composite resins namely Gradia (hybrid microfilled) and Omnichroma (super-nano filled), subjected to two polishing methods.    Materials and Methods: In this in vitro study, 100 composite specimens (50 Gradia and 50 Omnichroma) were fabricated and divided into two groups for polishing with disc and bur systems. The baseline surface roughness and color parameters (L*, a*, b*) were recorded. The specimens were immersed in a tea solution for 24 days to simulate staining, followed by in-office bleaching with 38% hydrogen peroxide. Surface roughness and color parameters were re-measured post-bleaching. Statistical analysis was performed using repeated-measures ANOVA to assess the effects of bleaching, polishing method, and composite type (alpha=0.05).    Results: The interaction effect of polishing method and composite type on surface roughness was not statistically significant (P>0.05). A significant change was observed in ΔL after polishing compared with the baseline (P = 0.018), indicating an increase in lightness for Omnichroma. For Δa, Gradia composite polished with disc exhibited significant redness after immersion in tea (P=0.022), while Δb results showed that Gradia had a significant shift to yellowness across all stages (P<0.05). Conclusion: The results showed that the surface roughness of both Gradia and Omnichroma composite resins increased after bleaching. Gradia exhibited more pronounced ΔE, particularly turning redder after immersion in tea, whereas Omnichroma displayed better color stability. These findings suggest that material selection and polishing methods are critical in maintaining esthetic outcomes in bleached composite restorations.

Islamic Azad University Dental Branch Journal of Research in Dental and Maxillofacial Sciences 2588-4166 10 3 2025 9 1 Repair Bond Strength of Aged Composite: Effect of Thermocycling and Surface Treatment 228 237 EN Sina Yarmoradian Department of Prosthetic Dentistry, School of Dentistry, Mashhad University of Medical Sciences, Tehran, Iran. Ladan Ranjbar Omrani Dental Research Center, Dentistry Research Institute, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran. Elham Ahmadi Dental Research Center, Dentistry Research Institute, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran. Niyousha Rafeie Department of Restorative Dentistry, Dental Research Center, Dentistry Research Institute, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran. Mahdi Abbasi Dental Research Center, Dentistry Research Institute, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran. Nastaran Dabiri Shahabi Department of Restorative Dentistry, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran. Background and Aim: A variety of surface preparation techniques have been applied to increase the repair bond strength of composite restorations. The current study aimed to assess how silane and/or plasma application, bur roughening, sandblasting, and thermocycling would affect the microshear bond strength (µSBS) of composite repair employing a universal adhesive.    Materials and Methods: The current in vitro study utilized 128 composite specimens (10 x 10 x 10 mm) that were stored in 37°C water for 4 weeks and then randomly divided into two groups (n = 64) for surface treatment by sandblasting or bur roughening. Then, each group was divided into four subgroups (n=16) and received surface treatments as follows: No plasma or silane, plasma application, silane application, plasma and silane application. The new composite was then bonded to each specimen using G-Premio Bond. Half of each subgroup (n=8) underwent 5000 thermal cycles, while the other half was stored in water for 24 hours. Finally, the repair µSBS was measured. Four-way ANOVA was used for data analysis (alpha=0.05).    Results: Thermocycling significantly decreased the µSBS (P=0.000). Significantly greater µSBS (13.35±3.82 N; P=0.014) was achieved when physical methods were used alone without plasma or silane. Silane reduced the repair µSBS following sandblasting, but significantly increased the repair µSBS after bur roughening. Plasma treatment did not have a significant effect on µSBS (P>0.05). Conclusion: Sandblasting greatly enhanced the repair µSBS. The repair µSBS of the roughened composite samples was unaffected by plasma treatment. The type of physical treatment determines how well silane improves the repair µSBS.

Islamic Azad University Dental Branch Journal of Research in Dental and Maxillofacial Sciences 2588-4166 10 3 2025 9 1 In Vitro Effects of Various Agents on Discoloration of Demineralized Enamel Caused by Silver Diamine Fluoride 238 247 EN Fahim Seraj Dentist, Private Practice, Tehran, Iran. Sara Tavassoli-Hojjati Department of Pediatric Dentistry, TeMS.C., Islamic Azad University, Tehran, Iran. Background and Aim: Silver diamine fluoride (SDF) is effective for arresting dental caries. However, its application results in dark tooth discoloration, raising concerns among pediatric patients and their parents. This study assessed the effects of potassium iodide (KI) plus hydrogen peroxide (H2O2), H2O2, and Tooth Stain Remover (TSR) on SDF-induced discoloration of artificially demineralized permanent enamel.    Materials and Methods: In this in vitro study, the buccal surface enamel of 33 sound premolars was artificially demineralized and exposed to 38% SDF. The specimens were then randomly assigned to 3 groups of (I) KI + H2O2 (application of water-soluble KI followed by 35% H2O2 on the discolored surface for 3 minutes), (II) H2O2 (application of 35% H2O2 for three 20-minute cycles), and (III) TSR (application of TSR for 3 minutes on the discolored surface). The color parameters were measured at baseline, 1 week after the application of SDF, and 1 week after the application of the abovementioned bleaching agents by a spectrophotometer. Data were analyzed by ANOVA and Tukey test (alpha=0.05).    Results: SDF caused significant color change (ΔE) of demineralized enamel in all groups (ΔE=36-40), with no significant difference among the study groups (P=0.361). Application of all bleaching agents significantly resolved the dark discoloration in all groups, but KI + H2O2 was significantly more effective than H2O2 and TSR (P<0.001). TSR was the least effective (P<0.001). Conclusion: Within the study limitations, the results showed optimal efficacy of KI + H2O2 for correction of 38% SDF-induced discoloration in artificially demineralized permanent enamel.

Islamic Azad University Dental Branch Journal of Research in Dental and Maxillofacial Sciences 2588-4166 10 3 2025 9 1 A Comparative Analysis of Resin-Modified Glass Ionomers and Composite Resins for Restoration of Non-Carious Cervical Lesions: A Systematic Review and Meta-Analysis 248 261 EN Azam Valian Department of Restorative Dentistry, School of Dentistry, Shahid Beheshti University of Medical Sciences, Tehran, Iran. Tahoura Madani Undergraduate Student, Department of Biomedical Engineering, Faculty of Engineering, South Tehran Branch, Islamic Azad University, Tehran, Iran. Neda Kheirkhah Dabbagh Department of Restorative Dentistry, TeMS.C., Islamic Azad University, Tehran, Iran. Background and Aim: The objective of this review was to assess the clinical efficacy of resin-modified glass ionomers (RMGIs) and composite resins for management of non-carious cervical lesions (NCCLs).    Materials and Methods: A systematic search was conducted using the Cochrane Oral Health Group Trials Register, MEDLINE via Ovid, EMBASE via Ovid, and PubMed Health, with no restrictions on language up to 2021. The review included randomized controlled trials (RCTs) with a minimum follow-up period of 12 months, comparing RMGI restorations to composite resin restorations in adult populations with NCCLs. The primary outcomes assessed were retention rate, marginal integrity, and marginal discoloration. The search results were rigorously screened, and relevant trial data were extracted. Additionally, the risk of bias for the included studies was evaluated. The results were presented as risk ratios (RRs) with 95% confidence intervals (CIs), and a meta-analysis was performed using Review Manager 5 (RevMan 5).    Results: Of 978 retrieved references, 12 trials (15 articles) were included in this systematic review. Nine trials were split-mouth studies involving 414 RMGI restorations and 454 composite restorations. The remaining three trials were parallel group studies involving 83 RMGI restorations and 131 composite restorations. The meta-analysis showed that RMGI restorations had a significantly lower failure rate (RR: 0.35, 95% CI: 0.23 to 0.52) than composite restorations. However, no significant difference was found between the two materials for marginal integrity and marginal discoloration (P>0.05). Conclusion: RMGI restorations exhibited superior clinical performance regarding the retention rate for NCCLs.