ABSTRACT Background: Bracket rebonding is a common problem in orthodontics which may result in many drawbacks. The aims of this study were to evaluate the effects of application of two enamel protective agents “Icon†and “ProSeal†on shear bond strength before and after rebonding of stainless steel orthodontic brackets using conventional orthodontic adhesive and to assess the site of bond failure. Materials and methods: Fifty sound extracted human upper first premolar teeth were selected and randomly divided into two equal groups; the first time bonding and the rebonding groups (n=30). Each group was subdivided into control, Icon and ProSeal subgroups. The enamel protective agents were applied after etching (preconditioners). Shear bond strength before and after rebonding of stainless steel brackets were assessed using the Universal testing machine and the adhesive remnant index was used to find out the bond failure site using a stereomicroscope. Then the results were statistically analyzed using one-way ANOVA analysis test and T-test. Results: There were no significant differences in the shear bond strength mean values in either group or their corresponding subgroups. Forty percentage of the bond failure in ProSeal groups occurred away from the enamel where 75% of those were at the enamel protective agents/adhesive interface. Conclusions: The application of Icon and ProSeal did not compromise the shear bond strength and the application of the ProSeal may protect the enamel surface from trauma (cracks, chipping or detachment).
Back ground: This in vitro study was carried out to investigate the effect of post space regions (coronal, middle and apical), Time and the mode of polymerization (dual, self-cured) of the cements used on the bond strength between translucent fiber post and root dentin by using push-out test. Materials and Methods: Forty eight extracted mandibular first premolars (single root) were instrumented with ProTaper Universal system files (for hand use) and obturated with gutta percha for ProTaper and AH26® root canal sealer following the manufacturer instructions, after 24 hours post space was prepared using FRC postec® plus drills no.3 creating 8 mm depth post space. The prepared samples were randomly divided into two main groups (24 samples ea
... Show MoreTo evaluate the shear bond strength and interfacial morphology of sound and caries-affected dentin (CAD) bonded to two resin-modified glass ionomer cements (RMGICs) after 24 hours and two months of storage in simulated body fluid at 37°C.
Sixty-four permanent human mandibular first molars (32 sound and 32 with occlusal caries, following the International Caries Detection and Assessment System) were selected. Each prepared substrate (sound and CAD) was co
Background: The aim of this in vitro study was to evaluate and compare the effect of preheating microleakage among three different filler size composites which include Filtektm Z250 micro hybrid, Z250xt Nano hybrid and nanocomposite Z350xt. in Class II cavity preparation .
Materials and methods: sixty maxillary first premolars were prepared with class II cavities. Samples were divided into three groups according to material used group A (FiltekZ250 micro hybrid). Group B(Z250xt Nano hybrid). Group C (nanocomposite Z350xt)and each group divided into two subgroups of ten teeth according to temperature of composite:
... Show MoreA novel demountable shear connector for precast steel‐concrete composite bridges is presented. The connector uses high‐strength steel bolts, which are fastened to the top flange of the steel beam with the aid of a special locking nut configuration that prevents slip of bolts within their holes. Moreover, the connector promotes accelerated construction and overcomes typical construction tolerances issues of precast structures. Most importantly, the connector allows bridge disassembly, and therefore, can address different bridge deterioration scenarios with minimum disturbance to traffic flow, i.e. (i) precast deck panels can be rapidly uplifted and replaced; (ii) connectors can be rapidly removed and replaced; and (iii) steel beams can b
... Show MoreBackground: Treatment of malocclusions using removable orthodontic appliances may prepare new stagnant areas susceptible for colonization and retention of Candida species, therefore; the aim of this study was to investigate the effect of upper removable orthodontic appliances on the mucosal Candidal count in group of apparently healthy orthodontic patients. Materials and Methods: Patients enrolled in this study were children aged 8-12 years having upper removable orthodontic appliances. Candidal counts at six mucosal sites were estimated using Imprint Culture method before, 14 and 28 days during orthodontic therapy. Results: Whole mouth and individual mucosal sites for Candidal counts increase significantly during treatment with upper remov
... Show MoreLimited importance of research in a stand on the most important difficulties faced by both faculty and parents to communicate with each process to follow up on their children, and the analysis and inventory of the obstacles that hinder the educational process, and work to develop a vision of how to address these constraints and the important role of technology in the treatment of problems of the society so as to develop frameworks future to minimize the errors and the problems they face, and the development outlook for future generations in order to promote the educational level, especially that Iraq is going through a change in conditions in all sectors. Through the questionnaire, which includes questions set that was made on a sample o
... Show MoreBackground: Cisplatin (CDDP) is an effective chemotherapeutic agent whose gonadotoxicity can lead to premature ovarian insufficiency through oxidative stress, inflammation, and apoptosis. Sodium–glucose cotransporter-2 (SGLT2) inhibitors exhibit cytoprotective effects, but their ovarian effects during chemotherapy remain poorly defined. Methods: Twenty-four female Wistar rats were randomized (n = 6/group) to Control (vehicle), Cisplatin (7 mg/kg, i.p., day 14), Cisplatin + dapagliflozin (DAPA; 0.9 mg/kg/day, p.o., days 1–14), or Cisplatin + empagliflozin (EMPA; 10 mg/kg/day, p.o., days 1–14). At 24 h post-cisplatin, serum estradiol (E2), progesterone, follicle-stimulating hormone (FSH), and Anti-Müllerian Hormone (AMH) were measured
... Show MoreBackground: Pit and fissure sealant have been considered an outstanding adjunct to oral health care in the decrease of occlusal caries onset and low progression. The aims of this in vitro study were to evaluate the marginal microleakage of three different types of fissure sealants (SDI, Tg and tetric N-flow) by time interval, one day and 45 days, in the presence or absence of bonding agent among maxillary and mandibular teeth. Materials and methods: Seventy two sound human maxillary and mandibular first premolar teeth were collected which were free from obvious carious lesions. The teeth were randomly divided into two main equal groups, group (1) and group (2), each group consists of (36) teeth involving equal numbers of maxillary and mandi
... Show MoreConsumption of different types of beverages and liquid drugs can affect of the surface properties of restorative material. This may lead to an increased probability of dental caries and periodontal inflammation.
This study evaluated and compared the effect of amoxicillin suspension (AMS) and azithromycin suspension (AZS) on the surface roughness (SR) of silver-reinforced gl