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Context: The result of the studies concerning the bonding of self-adhesive resin cements to dentin is controversial. Aims: To assess in vitro shear bond strength (SBS) of three self-adhesive dual-cured resin cements to dentin compared to a currently used dual-cured resin cement, using SBS test. Settings and Design: The extant study is an experimental in vitro one on extracted human third molars dentin. Material and Methods: 40 intact human third molars were selected and randomly divided into 4 groups of 10. Buccal dentin surfaces were exposed perpendicular to the long axis and prepared with SiC papers. A translucent plastic ring, was placed over the dentin surfaces. Group I (Control group): After 15 s of etching and application of Excite DSC Bond (Ex), Variolink II (Var II) resin cement was injected into the plastic ring and was light cured for 40 s. Group II: RelyX Unicem (RX) was injected into the plastic ring and after 30 s, was light cured for 40 s. Group III: Maxcem (Mc) was injected into the plastic ring and after 30 s, was light cured for 40 s. Group IV: Multilink Sprint (MS) was injected into the plastic ring and after 30 s, was light cured for 40 s. After thermal cycling, SBS were measured with a universal testing machine. Statistical Analysis Used: Statistical computations were conducted according to Student′s t-test. Results: The mean SBS and standard deviations (in parentheses) for groups I, II, III, and IV were 12.95 (2.64), 6.73 (0.79), 3.01 (0.90), 4.60 (0.75) MPa, respectively. Statistical analysis, revealed that: (1) the mean SBS of Var II were significantly higher than the other groups (P0.05). Conclusion: Bond strength of three self-adhesive resin cements was significantly lower than the conventional total-etch resin cement. RX significantly performed better SBS than Mc and MS to dentin.

Background: During sliding mechanics, the frictional force (FF) is an important counterforce to orthodontic tooth movement. The purpose of this in vitro study was to investigate the static and kinetic FFs of S silica-insert ceramic (SIC) brackets with Teflon-coated (TC) and conventional S stainless steel (SS) archwires. Materials and Methods: The target group of this study included 80 maxillary canine 0.022 inch slot SIC brackets. Forty SS brackets were used as the control. TC and conventional uncoated SS archwires of different dimensions (0.016, 0.018, 0.016 x 0.022, and 0.018 x 0.025 inch) were examined. All tests were carried out under artificial saliva injected condition. Scanning Electron Micrographs were prepared for two samples of coated and uncoated archwires. Analysis of variance and Tukey post hoc tests were used for statistical purposes (level of significance P < 0.05). Results: SIC brackets showed significantly lower levels of FFs than SS brackets. TC archwires had greater frictional values than conventional uncoated ones. They also exhibited an unusual behavior of increasing kinetic FFs with time. Indentation and delamination of coating were obvious under scanning electron microscopy observations. Conclusion: From the standpoint of friction, SIC brackets may serve well, even better than SS brackets, in sliding mechanics. The coating layer of the archwires may delaminate and lost, causing an impediment to tooth movement. [ABSTRACT FROM AUTHOR]

Introduction: The aim of this study was to evaluate the role of teeth and lips in the perception of smile esthetics. Materials and Methods: Thirty women, ranging between 20 and 30 years of age, all with Class I canine and molar relationships and no history of orthodontic treatment, were chosen. Five black and white photographs were taken of each participant in a natural head position while smiling. The most natural photo, demonstrating a social smile, was selected. Two other photographs were also taken from a dental frontal view of each subject using a retractor, as well as a lip-together smile. Three groups of judges including 20 orthodontists, 20 restorative specialists, and 20 laypersons were selected. The judges were then asked to confirm the esthetics of each picture on a visual analogue scale. An analysis of variance (ANOVA) and the Pearson correlation test were used for statistical analysis. Results: For the orthodontists group, correlation between the scores given to the full smile and each of its components was significant (α=0.05), with equal correlation of each component with the full smile. In contrast to laypersons, the correlation between the scores given to the full smile and each of its components among restorative specialists was significant. Conclusion: For orthodontists and restorative specialists, esthetic details and the components of the smile (teeth and perioral soft tissues) were important in esthetics perception. In contrast, laypersons perceived no effect of esthetics detail or smile components. [ABSTRACT FROM AUTHOR]

Introduction: Guiding anterior crossbite to a normal position is one of the most important responsibilities of a pediatric dentist or orthodontist to gain both esthetic and function. Crossbite with dental etiology can be treated by a variety of appliances. We describe a removable appliance with a different spring design for proclination of more than one incisor in mixed dentition., Materials and Methods: This study is an observational study that was performed on sixteen children, 7-11 years of age, who needed incisor proclination in more than one tooth. In this study, patients were followed until the end of their orthodontic therapy. The variables evaluated were the maxillary arch length, arch depth, intercanine distance, and intermolar distance in pre- and posttreatment. To assess intra-examiner reliability, 10 plaster models were randomly selected and re-measured., Results: In all the cases, the newly designed removable appliance was used and in all showed a significant increase in arch length, arch depth, intercanine distance, and intermolar distance. The correction was achieved within 1-9 months depending on the patient's compliance., Conclusion: There was a significant increase in all aspects of arch length and depth after using this appliance. The procedure is a simple and effective method that is recommended for compliant patients needing proclination of more than one anterior tooth; especially in dental class III, pseudo-class III patients, and the first phase of class II division 2 skeletal treatments., How to Cite This Article: Bozorgnia Y, Mafinezhad S, Pilehvar P. Introducing a Removable Orthodontic Appliance and Its Effects on Dental Arch Dimensions. Int J Clin Pediatr Dent 2021;14(S-1):S39-S43., Competing Interests: Source of support: This work was supported by the North Khorasan University of Medical Sciences, Bojnurd, Iran (Grant No. 97/P/56). Conflict of interest: None, (Copyright © 2021; Jaypee Brothers Medical Publishers (P) Ltd.)