Objective. This study aimed to evaluate the orthodontic bond strength and enamel-preserving ability of a hydroxyapatite nanoparticles-containingself-etch system following exposure to various ageing methods. Materials and Methods. Hydroxyapatite nanoparticles (nHAp) were incorporated into an orthodontic self-etch primer (SEP, Transbond™ plus) in three different concentrations (5%, 7%, and 9% wt) and tested versus the plain SEP (control) for shear bond strength (SBS), adhesive remnant index (ARI) scores, and enamel damage in range-finding experiments using premolar teeth. The best-performing formulation was further exposed to the following four artificial ageing methods: initial debonding, 24 h water storage, one-month water storage, and one-month acid challenge. A field-emission scanning electron microscope (FE-SEM) was used to examine the integrity of debonded enamel surfaces and calcium-phosphates (CaPs) reprecipitation. Results. The best-performing formulation (7% nHAp-SEP) resulted in significantly lower SBS (
Background: The therapeutic goal of orthodontic treatment is to establish ideal occlusion which includes both static and functional aspects. The objective of this study was to clarify functional occlusal treatment goals by analyzing functional occlusion in subjects with established normal occlusion and identify the differences between canine protected occlusion and group function occlusion. Materials and Methods: The sample consisted of 62 subjects with normal occlusion and with an age range of (18-25 years).Functional occlusal contacts during lateral excursion were identified on a fully adjustable articulator, and then the samples were classified according to: 1) Type of functional occlusion: A) Canine protected occlusion group (canine pr
... Show MoreOrthodontic treatment has two major problems: being lengthy and costly procedure. The present study was designed to evaluate the clinical efficacy of locally injected vitamin D3 Keywords: Orthodontic, Calcitriol, Local injection, OTM (calcitriol) in accelerating orthodontic teeth movement (OTM) and reducing treatment time and cost in humans. The study was performed on 15 Iraqi adult orthodontic patients within the age range 17-28 years, they are randomly allocated into three groups, each of five patients and treated with either 15 pg, 25 pg, or 40 pg/0.2ml calcitriol diluted with 10% dimethylsulfoxide (DMSO). The maxillary arch of every patient was divided into control (right) and experimental (left) sides. In addition to force application,
... Show MoreThe current research dealt with the issue of organizational skillfulness as an entry point to reach strategic agility. The study has been tested in Iraq's mobile operators - Asia Cell, Zain Iraq and Cork Telecom. The study was applied to a sample of (93) managers distributed at various levels of management (board members, general managers, commissioners, department managers, people managers, unit managers, office managers). The survey used the questionnaire as a key tool for collecting data and information as well as personal interviews. It has sought to test a number of hypotheses related to correlation and influence relationships between the variables of the study, in order to answer the questions related to the problem of stud
... Show MoreIn his opus, Ted Hughes has annexed new and fresh territories of signification to the very notion of the literary animal. Building on the earlier modernist example of the Lawrencian legacy that dwells upon the question of animalism, Hughes seems to have stepped further into the terrain of the sheer struggle when, in his hands, the grotesquerie of survival and violence energizes the topos of the literary animal in his postmodern bestiary. In Hughes’s elemental poetic process this grotesquerie and violence stages the literary animal as a vital poetic device or motif that is finally restored to the primitive power of poetry. In his “Thrushes”, he thus defamiliarizes these tiny creatures’ acts of being to bring upfront into focus thi
... Show MoreBackground: Eucalyptus extracts and derivatives are natural substances with potent antimicrobial properties. This study investigated the in- vitro effects of non-nutritive sweeteners on the antifungal activity of alcoholic and aqueous Eucalyptus extracts against Candida albicans, a common oral pathogen. Materials and Method: Ten isolates of Candida albicans were isolated from dental students’ salivary samples. The alcoholic and aqueous extracts were prepared from fresh Eucalyptus leaves using maceration. The sensitivity of Candida albicans isolates to various concentrations of Eucalyptus extracts ranging from 50 to 250 (mg/mL) was evaluated via agar well diffusion method, while the agar streaking method was used to assess the minimum
... Show MoreBackground: Many types of instruments and techniques are used in the instrumentation of the root canal system. These instruments and techniques may extrude debris beyond the apical foramen and may cause post-instrumentation complications. The aim of this study was to evaluate the amount of apically extruded debris resulted by using 4 types of nickel-titanium instruments (WaveOne, TRUShape 3D conforming files, Hyflex CM, and One Shape files) during endodontic instrumentation. Materials and methods: Forty freshly extracted human mandibular second premolar with straight canals and a single apex were collected for this study. All teeth were cut to similar lengths. Pre-weighted glass vials were used as collecting containers. Samples were randoml
... Show MoreBackground: The study aim was to evaluate thermocycling effect on microleakage of occlusal and cervical margins of MOD cavity filled with bulk filled composites in comparison to incrementally placed nanohybrid composite and to evaluate the difference in microleakage between enamel and dentin margins for the three materials groups. Materials and method: Forty eight maxillary first premolars were prepared with MOD cavities. Samples were divided into three groups of sixteen teeth according to material used: Grandio: Grandio. SDR: SDR +Grandio. X-tra: X-tra base + Grandio. Each group was subdivided into two according to be thermocycled or not. After 24 hrs immersion in 2% methylene blue, samples weresectioned and microleakage was estimated. Res
... Show MoreBackground: Surgical injury to alveolar bone can temporarily accelerate tooth movement by increasing the remodeling rate of alveolar bone. The purpose of this study was to clinically evaluate maxillary canine retraction acceleration with corticotomy-facilitated orthodontics, and its effect on vitality of pulp and gingival sulcus depth. Materials and method: The sample consisted of 12 adult patients (4 males, 8 females; mean age, 21.7 years) requiring the therapeutic extraction of the maxillary first premolars, with subsequent retraction of the maxillary canines. Surgical holes were done mesially and distally to the side with more space between canine and second premolar, and the other side served as the control. Canine retraction was done
... Show MoreIn this work, the switching nonlinear dynamics of a Fabry-Perot etalon are studied. The method used to complete the solution of the differential equations for the nonlinear medium. The Debye relaxation equations solved numerically to predict the behavior of the cavity for modulated input power. The response of the cavity filled with materials of different response time is depicted. For a material with a response time equal to = 50 ns, the cavity switches after about (100 ns). Notice that there is always a finite time delay before the cavity switches. The switch up time is much longer than the cavity build-up time of the corresponding linear cavity which was found to be of the order of a few round-trip ti
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