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Q: TypeError: Object function Object() { [native code] } has no method 'observe' I recently came to know this function Object.observe() and tried implementing in my app.
var cs = {
    name : "java",
    version : "1.0"
}

cs.name = "javascript";
function doThis(){
    console.log(cs.name);
}
Object.observe(cs, doThis);

But I see the above mentioned error.
TypeError: Object function Object() { [native code] } has no method 'observe'

Can some one throw some light on what am I missing here.

A: If I'm not mistaken it only exists in google canary at the moment, it is an extremely new JS prototype.
You are getting this error because the browser you are using does not have it implemented.


Most refugee children will spend their entire childhood in exile. Responding to their educational needs will require innovative policy solutions that put teachers at the centre. To help advance this, IIEP, together with Education Development Trust, has launched the pilot of a new policy study in Ethiopia.
Research has shown that the quality of teachers and teaching are the most important factors affecting student outcomes among those that are open to policy influence. Presumably, this also applies in refugee situations, especially given that teachers themselves are often the only educational resource available to students in times of crisis.
However, a literature review conducted earlier this year by IIEP-UNESCO and Education Development Trust (EdDevTrust) found that relatively few data are available about teachers of refugees, other than limited statistical data suggesting that qualified teachers are in short supply. The review also concluded that, with the exception of some research exploring certification and compensation in refugee contexts, there are few studies on teachers' perspectives on key policy issues, including recruitment, deployment, professional development, and motivation.
To begin to address this evidence gap, IIEP partnered with EdDevTrust, with support from UNICEF, Open Society Foundations, and other stakeholders, to launch a multi-country policy study on the management of teachers of refugees. It aims to answer what effective and promising policies and implementation strategies exist for the management of teachers in refugee contexts, and where potential space for further policy development and successful implementation exists (Access the concept note here).
Ethiopia has been selected as the pilot country for this research because, not only is it home to one of the largest refugee populations in Africa, but it is one of the first countries to attempt to roll out the global Comprehensive Refugee Response Framework, which builds on the idea that refugees should be included in host communities. As part of this, Ethiopia has come up with a set of nine pledges for policy reform, a number of which directly affect education. These include the proposed issuing of work permits to refugees, which would apply to teachers, efforts to expand enrolment of refugee children at all levels of the school system, and attempts to build and improve essential services for refugees more broadly.
While these policy developments hold promise for improved quality and greater access to education for refugees in Ethiopia, there are often significant differences between how policies are developed and implemented. This study uses a multi-phase, mixed methods research design to explore how the proposed policy reforms are being interpreted, mediated, and struggled over at the national, regional, district, and school level.
So far, the research has included an initial analysis of policy documents, in collaboration with a group of students from the McCourt School of Public Policy at Georgetown University in the United States. In October, the first field visits took place with support from local researchers from PRIN International. The preliminary results of this first data collection mission stressed the importance of responding to context, as there are significant variations across the different regions of Ethiopia and the refugee population is far from homogeneous. A variety of policy options are required to respond to the education needs of the millions of young people who call Ethiopia home today.
Later this year, a teacher survey tool will be refined and implemented in various parts of the country. A follow up mission to Ethiopia will take place in early 2019, which will include in-depth case studies and interviews with key stakeholders.
Authored by Stephanie Bengtsson, Programme Specialist, IIEP-UNESCO. This article will also appear in our upcoming IIEP Letter on the future of the teaching profession.
Read the concept note of Who Teaches Refugees?


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Volume 2015, Article ID 791725, 11 pages
Surface Modifications and Their Effects on Titanium Dental Implants
A. Jemat,1 M. J. Ghazali,1 M. Razali,2 and Y. Otsuka3
1Department of Mechanical & Materials Engineering, Faculty of Engineering and Built Environment, UKM, 43600 Bangi, Selangor Darul Ehsan, Malaysia
2Department of Peridontology, Faculty of Dentistry, National University of Malaysia, Jalan Raja Muda Abdul Aziz, 50300 Kuala Lumpur, Malaysia
3Department of System Safety, Nagaoka University of Technology, 1603-1 Kamitomioka-Cho, Nagaoka-shi, Niigata 940-2188, Japan
Received 2 April 2015; Revised 15 June 2015; Accepted 16 June 2015
Academic Editor: Seunghan Oh
Copyright © 2015 A. Jemat et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
This review covers several basic methodologies of surface treatment and their effects on titanium (Ti) implants. The importance of each treatment and its effects will be discussed in detail in order to compare their effectiveness in promoting osseointegration. Published literature for the last 18 years was selected with the use of keywords like titanium dental implant, surface roughness, coating, and osseointegration. Significant surface roughness played an important role in providing effective surface for bone implant contact, cell proliferation, and removal torque, despite having good mechanical properties. Overall, published studies indicated that an acid etched surface-modified and a coating application on commercial pure titanium implant was most preferable in producing the good surface roughness. Thus, a combination of a good surface roughness and mechanical properties of titanium could lead to successful dental implants.
Surface treatments are normally carried out to modify yet maintain desirable properties of the substrate materials especially in the dental implant industry. The surface area can be increased remarkably by using proper modification techniques, either by addition or subtraction procedures [1, 2]. A surface treatment can also be classified into mechanical, chemical, and physical methods. In dental implant, the surface treatment is used to modify the surface topography and surface energy, resulting in an improved wettability [3–5], increased cell proliferation and growth [3], and accelerated osseointegration process [6]. The quality of dental implant depends on the properties of the surface. In order to have good interaction of the tissue and osseointegration, materials' biocompatibility and roughness of the surface played an important role. Goyal and coworkers [7] observed that the increased roughness can simultaneously increase the surface area of the implant, improve cell migration and attachment to implant, and enhance osseointegration process. Past literature has revealed most of the surface treatments able to brings a good effect to the dental implants [3–6]. Coating is proved to increase the surface area of the implants substantially [8]. The surface treated with plasma sprayed titanium exhibits the highest value of the surface roughness ( μm) compared to machined surface ( μm) [9]. The healing period was enhanced with hydroxyapatite (HA) coating compared to untreated one [10]. The behavior of modified surface on cells culture studies has revealed that an acid etched zirconia implant surface shows a significant improvement in cell proliferation, except for bone attachment and adhesion on the first day of culture [11–13]. In the study by Parsikia et al. [14], the commercially pure titanium surface was blasted followed by two-step chemical treatment (acid-alkali) resulting in optimized surface topography. The cell bioactivity was improved and expected to have good osseointegration at early stage. Furthermore, a rougher titanium surface promotes shorter healing process [15] than the smoother surfaces. Thus, the surface treatment is used not only to maintain the existing properties of the implants but also to enhance several behaviours as required by dental applications particularly in improving the healing process.
2.1. Titanium Implant
Titanium is the material of choice for dental implant as its properties met the most important requirements such as excellent biocompatibility [16], corrosion resistance, high strength, and relatively low modulus of elasticity [17], good formability, and machinability. Additionally, surface modifications are being utilised on implant surfaces, mainly to improve wettability, cell-implant adhesion and attachment, cell proliferation, and osseointegration, and thus faster healing and shorter treatment duration. As a result, many research works have been carried out to improve surface modifications on existing implants to achieve the desired biological responses. The surface topography has also been manipulated such as acid etching and blasting [18] onto the surface to get a better topographies which consequently bring better roughness. In the case of the mechanisms, the roughness of the titanium implants was considered to be one of the significant parameters that affect the rate and the quality of osseointegration [15, 18, 19].
2.2. Biocompatibility of Titanium and Its Alloys
Materials compatibility is the most important issue to be considered for a successful dental implantation. Titanium and its alloys are well known as materials that are well tolerated by living tissues and capable of promoting osseointegration [20]. Ideally, the modification of the implant surface was proposed to enhance osseointegration between materials and bone tissue. The surfaces of materials after treatment should be able to interact with the surrounding tissue to induce direct contact of bone to implant. Kokubo treatment, also known as simulated body fluid (SBF), is a chemical method for inducing or determining a level of biocompatibilities property of dental materials that was established in 1991 [21]. SBF can be described as a solution with ion concentration similar to human blood plasma (see Table 1), kept under mild conditions of pH and identical physiological temperature [21]. The history of SBF usage for apatite formation is shown in Figure 1 [21–25]. In early 1980, Ogino and coworkers [22] have found silicon dioxide (SiO2) layer and calcium phosphate (CaP) formed on a Bioglass which allows bonding to living bone. In 1990, Kokubo et al. [24] have stated that the formation of apatite is an essential for osseointegration between implant surface and living bone. The full preparation of SBF has been reported in 1995 by Cho et al. [25].
Table 1: Ion concentrations (mM) of SBF and human blood plasma [21].
Figure 1: History of simulated body fluid (SBF).
In vivo and in vitro bioactivity of a material can be predicted from the apatite formation on its surface in SBF [26]. Surface conditions, such as surface roughness, surface charge, surface energy, and chemical composition, have important influences on the osseointegration process. Therefore, modifying titanium implant surface seems to be a promising way to achieve stronger and faster osseointegration of the implants and also promoted shorter healing times from implant placement to restoration [27].
2.3. Surface Treatment
Recently, many works have been carried out on surface treated commercial titanium implants to enhance the osseointegration function (references). By increasing the surface roughness, an increase in the osseointegration rate and the biomechanical fixation of titanium implants have been observed [27, 28]. The implant modifications can be achieved either by additive or subtractive methods. The additive methods employed the treatment in which other materials are added to the surface, either superficial or integrated, categorized into coating and impregnation, respectively. While impregnation implies that the material/chemical agent is fully integrated into the titanium core, such as calcium phosphate crystals within TiO2 layer or incorporation of fluoride ions to surface, the coating on the other hand is addition of material/agent of various thicknesses superficially on the surface of core material. The coating techniques can include titanium plasma spraying (TPS), plasma sprayed hydroxyapatite (HA) coating, alumina coating, and biomimetic calcium phosphate (CaP) coating. Meanwhile, the subtractive techniques are the procedure to either remove the layer of core material or plastically deform the superficial surface and thus roughen the surface of core material. The common subtractive techniques are large-grit sands or ceramic particle blasts, acid etch, and anodization [19]. The removal of surface material by mechanical methods involved shaping/removing, grinding, machining, or grit blasting via physical force. A chemical treatment, either by using acids or using alkali solution of titanium alloys in particular, is normally performed not just to alter the surface roughness but also to modify the composition and to induce the wettability or the surface energy of the surface [29]. As for physical treatment such as plasma spray or thermal spray, it is often carried out on the outer coating surface to improve the aesthetic of the material and its performance. Additionally, ion implantation, laser treatment and sputtering [10, 30–33], alkali/acid etching [34–36], and ion deposition [37] are also utilised. Thus, in the light of studying the effects of surface treatments, this review only focuses on various methods that have high potentials in improving the performance of titanium implants. The basic principle of each surface modification and its developments are discussed in the following sections:(i)Pretreatment significance.(ii)Plasma spray coating.(iii)Grit blasting.(iv)Acid etching.(v)Dual acid etching (DAE).(vi)Sand blast and acid etching (SLA).(vii)Other methods.(viii)Trends in surface treatment of titanium.(ix)Final remarks.
2.3.1. Pretreatment Significance
Prior to the surface modification, pretreatment is required to ensure the substrate surfaces are free from contaminations. Prior to plasma spray procedure, the substrates are normally pretreated by grit blasting [38, 39] to remove the surface impurities and roughened (roughness range 3–5 μm) the surface in order to get better adhesion between substrate and powder [40]. The substrate can also be preheated to reduce residual stress and to avoid crack in the coating [38]. As for an acid etching method, the surface was prepared by polishing with several grits of sand papers [41] to achieve uniform [42] and regular morphology of the surface [43]. Typical surface roughness that is obtained from polishing process is in the range of ~0.1 [44, 45] to 3 μm [43]. Figure 2 shows the typical morphologies of Ti alloy polished using silicon carbide (SiC) grit papers. In short, a pretreatment process is crucial as it provides clean surface, by eliminating undesired defects like scratch and irregularities.
Figure 2: Typical morphologies of Ti alloy polished using SiC paper (a) 1200 grit, (b) 600 grit, and (c) 180 grit [42].
3. Type of Surface Treatment
3.1. Plasma Spray Coating
Plasma spraying technique generally involves thick layer of depositions, such as hydroxyapatite (HA) and titanium (Ti). The coating process includes spraying thermally melted materials on the implant substrates. A combination of HA coating on Ti alloys substrate has received many attentions due to their attractive properties such as good biocompatibility and mechanical properties [32]. The plasma spray substantially increased the surface area of the implants by increasing their surface roughness [46]. The potential of spray plasma spray coatings to enhance the mechanical behaviour has been addressed by many studies [9, 17, 18, 31, 37, 38]. Several techniques were proposed to adhere HA to titanium implants [9, 10, 17], but only the plasma spraying coating technique has been successfully used on commercial implants [19]. A metastable calcium phosphate solution provides excellent bioactivity of the HA/YSZ/Ti-6Al-4V composite coatings, which have the ability to induce bone-like apatite nucleation and growth on implant surface [38]. Fouda et al. [10] reported that HA coated titanium implant could enhance the healing period compared to the uncoated implants. Xie et al. [33] also discovered that HA coatings promote better cell proliferation. However, in some cases, a reverse effect of HA coatings [47, 48] was also noted. According to Liu et al. [49], the bonding strength of HA on titanium alloys decreased long hours of immersion time in the simulated body fluids (SBF). Yang et al. [48] also reported that after an immersion in the SBF, the hydroxyapatite (HA) coatings became weak due to the intermellar or cohesive bonding degradation in the coating. However, Knabe et al. [9] found that a plasma sprayed titanium surface exhibits the highest surface roughness compared to a deep profile surface structure (the surface was acid etched and grit blasted; see Figure 3) and in an in vitro test, the HA coating has less bone contact compared to other surface modifications. Some reports showed that the mechanical properties of HA can be significantly improved by the addition of yttria-stabilized zirconia [40, 50]. Previous study [51] reported that the HA coatings reinforced with zirconia possessed better performance in bond strength and dissolution behaviour of the titanium implants. Over the same period (4 weeks after the SBF immersion), the HA/YSZ/Ti-6Al-4V composite coating showed a reduced tensile strength by ~27.7% compared to the pure HA coatings with ~78.8% [38]. It has been reported that more new bones are formed and grow more rapidly into pores of the surface of alkaline-modified plasma sprayed implants, and this may be beneficial to reduce clinical healing times and thus to improve implant success rates [52].
Figure 3: Surface morphology by (a) plasma sprayed titanium (b) deep profile structure [9].
3.2. Grit Blasting
Another route for roughening the surface is grit blasting, through pressurised particle projection either using ceramic materials or silica onto the implant surface. Materials such as sand, hydroxyapatite, alumina, or TiO2 particles are usually employed for the purposes [35, 36]. Grit blasting is always followed by an acid etching to remove the residual blasting particles. Hence, the grit blasting is also considered as one of the means to embed surface contaminants on the substrates [51]. Surface microhardness of zirconia particles on titanium surface via blasting was found to be far greater than a controlled polished titanium surface [19]. Al-Radha and coworkers [53] evaluated the effect of bacterial adhesion on several titanium implants with different treatments. The results showed that ZrO2-blasted titanium exhibited greater bacterial adhesion compared to other surface treatments. In a similar case, Aparicio et al. [34] applied alumina blasting with particle sizes ranging 425–600 μm to gain high value of surface roughness between μm. In in vivo studies by Bacchelli et al. [54], they discovered that deposited titanium treated with commercially pure Ti shows the highest surface roughness of μm, followed by ZrO2 sandblasting with improved osteogenesis. This indicates that the blasting method also has an effective role in inducing optimum roughness of dental implants surface [3]. However, this technique is only promising in a good surface but not in terms of osseointegration itself. Besides, bacteria will tend to accumulate more on the rough surface substrate compared to smooth substrate. Thus, further study on how this technique affects the important properties like bone implant contact, removal torque values, tissues response, and bacterial adhesion, and biocompatibility must be carried out.
3.3. Acid Etching
In acid etching, the use of acids on metal surfaces is not only to clean the surface but also to modify the roughness. A strong acid like hydrofluoric (HF), nitric (HNO3), and sulphuric (H2SO4) or a combination of these acids is commonly used in this technique. Acid etched surfaces had increased cell adhesion and bone formation, thus enhancing the osseointegration [3, 49–51, 53, 54, 59–62]. Due to its dissolution ability [63, 64], HF has been used for etching restorative ceramic materials in order to increase the bonding surface for luting agents. The significance of this technique also renders the substrate with homogeneous roughening regardless of the sizes and shapes [63]. The roughness of titanium is one of the factors that helps in determining the stability of bone formation and resorption at the interface of bone implants [65]. Alla et al. [66] reported that a nanotopography that allows bone ingrowth via acid etching on an implant may improve the roughness. Previous study has reported that the rate of etching depends on the type and concentration of the acid used [35]. However, the suitability of these acids in etching was not determined as they required further tests particularly on the bone implant contact and torque removal. Titanium samples etched by H2SO4 with different concentrations demonstrated an increase in surface roughness [57]. Concentrated H2SO4 has been proven as an effective solution to roughen the surfaces particularly for biological applications [66].
3.3.1. Dual Acid Etching (DAE)
Similar to acid etching, the DAE is also able to treat the surface via chemical or acid whether in sequence [45] or with the combination of both [67, 68]. Rapid osseointegration can be achieved by dual etching through micro rough surface [55]. A comparative study between a machined surface and those using HF and HCl/H2SO4 (DAE) has shown the acid treated surface has greater resistance to reverse torque removal and better osseointegration [55]. In order to examine the surface roughened by the DAE, Yang et al. [48] inserted fifteen implants into rabbit's tibias. It was remarkable to note that roughened surfaces implants showed greater value of a removal torque at 2, 4, and 8 weeks than the machined surface. At the same time, a histomorphometric analysis demonstrated that the bone-to-implant contact significantly increased along with the peri implant bone formation. Thus, the DAE can provide a surface with a certain microroughness, thus contributing to a rapid osseointegration [35]. However, the acid etching treatment is strongly dependent on the acid selection and the process. Juodzbalys et al. [69] observed that an acid etched titanium implant exhibited similar surface topography as those gained from a sand-blasted large-grit acid etched (SLA) surface treatment. They found that the sample of titanium shows a good surface roughness with 1–10 μm micropits after etching with H2SO4 and then HCl compared to a poor surface microtexture by HCl and then H2S04 [69]. A comparison study had also been carried out between a machined surface and a dual-etched surface as shown in Figure 4.
Figure 4: Titanium implant with (a) a machined surface and (b) treated dual acid 48% HF + HCl/H2SO4 [51].
It was noted that the acid treated surface gave greater resistance in a reverse torque removal and better osseointegration than the machined surface implants [55]. A surface treatment via acid etching on zirconia implant has been reported to have similar effects on density of the bone implant and relative capacity for an osseointegration [61]. However, side effects like porosities, with sizes ranging from 0.5 to 2 μm, were also formed due to the use of these acids [58, 70]. This process somehow is also believed to benefit tissue ingrowth and cell surface interactions in the dental implant [70]. The success of osseointegration or implant anchorage was measured using a resistance to reverse torque rotation. As torque rotation force value increased, bone-to-implant contact (BIC) also increased which lead to greater osseointegration [51].
3.4. Sandblast, Large-Grit, and Acid Etching (SLA)
SLA is used to induce surface erosion by applying a strong acid onto the blasted surface [17]. This treatment combines blasting with large-grit sand particles and acid etching sequentially to obtain macro roughness and micro pits [58] to increase the surface roughness as well as osseointegration [71–74]. Cho and Jung [71] discovered that the SLA surface possessed wide cavities (from 5 μm to 20 μm in diameter) and micro pits (from ~0.5 μm to 3 μm in diameter), indicating an increase in the surface roughness and the surface area. Hence, the SLA-treated surface was found to be useful for improving tissue integration and cell proliferation. In vivo studies on six adult dogs carried out by Xue et al. [52] indicated that the surface after sequential grit blasting and alkaline treatment showed high shear strength, improving early bone growth and osseointegration. A recent investigation on a two-step chemical treatment (acid-alkali) noticed that optimised morphology and good bioactivity resulted in good osseointegration during the early stage of the implantation [75]. Similarly, He et al. [76] also discovered that the implants treated with blasting followed by the DAE (HCl and H2SO4) promote better osseointegration during the healing phase, indicating a great improvement in the bioactivities. In addition, biological evaluation by Kim et al. [58] discovered that human osteoblasts grow splendidly on the SLA surface which provides greater space for cell attachment and proliferation. Surface morphology for SLA typically became rough and irregular after sandblasting, but then after the acid etching treatment the surface is more uniform and small micro pits (1-2 μm in diameter) are created as shown in Figures 5(a) and 5(b).
Figure 5: The surface morphology of (a) sandblasted and treated Ti6Al4V alloy implants with DAE (HCl and H2SO4) [57] and (b) sandblasted and etched Ti implant with warm HCl [58].
3.5. Other Methods
Ion implantation, laser treatment, sputtering, and other combinations of several mentioned techniques are also briefly discussed in this review. An ion implantation, for example, involved accelerating ions of materials in an electrical field and impact onto the substrate to a depth of approximately 1 μm [1]. Braceras and his colleagues [37] used this method to investigate the osseointegration properties of the treated implant surface. They found out that the ion implantation of cobalt onto titanium alloys significantly improved the osseointegration. Deposition via dip coating of nanocomposite (HA-ZrO2-Al2O3) on titanium substrate showed the highest adhesion strength compared to the HA coatings [37]. Another technique observed by Pető et al. [77] involve Nd glass laser, in which the removal torque of implants was 20% larger for laser-treated surface compared to the machined and blasted implants. These results corresponded well with the data reported by Hallgren et al. [75] who demonstrated that the removal torque value was larger for the laser-modified implant (52 Ncm) than the machined surface implant (35 Ncm) after 12 weeks of healing. This result was also in agreement with other studies [9, 78–81]. Using pulsed magnetron sputtering method [72], ZrO2-Ag and ZrO2-Cu deposited titanium surface had improved the antibacterial performance relative to pure Ti implant materials [58]. In another study, combination method of laser-treated and acid etched surface was proven to have better osseointegration than the laser-treated surface with BIC value 49.71% [80].
4. Trends in Surface Treatment of Titanium
The greatest interest has been noted in the use of plasma spraying and acid etching techniques. Clearly, the plasma spray method is the most preferable (see Figure 6) due to its advantages in providing porous implant surfaces for greater bone contact [30]. The qualities of the coating surface are strongly dependent on the types of the coating materials. Other than that, study on plasma spray showed good growth cells on the implant surface [9] and a good bone contact which accelerated the bone formation [30]. Relatively, coated implants like ZrO2 possessed high surface roughness with an approximation of μm. This value could be increased up to μm [47] when acid etching is applied prior to coating. Even the dual acid etching played an important role in producing good surfaces, with roughness ranging from 0.44 to 3.51 μm [34, 35, 82]. In general, the DAE is better than a single acid etching due to its high composition, amount, and concentration. In the case of dental implants, the effect of acid etching is based on the concentration and the type of the acid as well as the temperature and time, in which the surface roughness normally increased with an increasing concentration of acid [67]. Furthermore, the blasting and the SLA techniques were also commonly used to improve the surface roughness and have high potential to improve the implant bone healing. Every single technique has its own advantages and limitations. Thus, to ensure high quality of the coated materials, the importance of a pretreatment on the surface prior to depositing work must also be considered.
Figure 6: Surface treatments commonly used in titanium dental implants.
In this paper, important methodologies that have been extensively utilised in the surface treatment work of titanium dental implants are summarised in Table 2. In spite of the high number on plasma spray method of studies to date, the results in the literature demonstrate difficulties in deciding the optimum value of surface roughness for better osseointegration yet decrease bacterial adhesion.
Table 2: Studies on the surface treatment on Ti dental implants.
5. Final Remarks
All in all, the coating techniques contribute to important positive effects of dental implant application. Most authors [6, 9, 30, 31, 33, 56, 79–81, 83–86] agreed that a good coating technique may give high impact on the mechanical properties of the dental implants. However, this technique has several limitations including poor long-term adherence of the coating to the substrate material [76], nonuniformity in thickness of the deposited layer [84], and variations in crystallinity [87] and composition of the coating. On the practical side, a better understanding of the suitable parameters during plasma spray is important in order to control these limitations. In contrast, most studies could not determine any major advantages or disadvantages with blasted surface implants. Blasting is one popular technique for surface treatments which can easily roughen the implant surface but is inadequate to give credit to the important properties like bone implant contact, removal torque values, tissues response, and biocompatibilities. Ion implantation technique on the other hand is useful to harden the surface of titanium but not applicable for dental implant [64]. It is most useful in orthopaedic devices which are subject to articulating or in wear situations. Another preferable surface treatment technique is the DAE that has high composition, amount, and concentration [63]. To date, ceramic coatings (calcium phosphate, HA, and TiO2) still remain the most popular bioceramic materials in the surface treatments area. Nevertheless, HA is recognised as the best candidate in bioceramics compared to TiO2 [76]. Meanwhile, zirconia also has good potential as dental implants whereby it promotes higher microhardness [33] and better mechanical properties when coated onto Ti alloy. Zirconia stabilized with yttria (YSZ) particles as a secondary phase in coatings is also believed to be dispersion-strengthened due to the homogeneous distribution of YSZ particles in the matrix [84], resulting in good bonding within the composite, and hence improves the mechanical properties.
Currently, surface roughening (e.g., grit blasting, acid etching, and SLA) and coating (e.g., with CaP and HA) are commonly used techniques in practice. Both methods have their advantages and drawbacks as we have discussed in this paper. It has been reported that the improvement of bone implant interface and greater resistance of failure were influenced by acid etched surface [45]. In addition, sandblasted with large-grit (25–50 mm) and acid etched surface were found to have a 50–60% mean value of bone implant contact compared to titanium plasma sprayed surface which had only a 30–40% mean value of bone implant contact after 6 weeks [46]. BIC value is very important in long-term success of dental implants. Numerous studies have demonstrated that rough implants surface show better bone apposition and BIC than implants with smooth surfaces [22, 46, 75]. Surface roughness also stimulated the cell migration and proliferation which in turn leads to better BIC [50]. Different modification methods have been studied, namely, sandblasted, large-grit, acid etched (SLA) and coated surfaces that were chemically different but had the same physical properties that were conducted to assess BIC as a measure of osseointegration.
It is clearly noted that by altering or modifying the surface texture, namely, the roughness of titanium implants, in particular, desired effects can be obtained like bone implant contact, removal torque values, tissues response, and biocompatibility. Thus, most works still favour surface treatment of dental implants via coating and acid etching over other methods in producing good substrate surfaces for osseointegration, with surface roughness ranging from 0.44 to 8.68 μm. In short, a good surface with the right roughness and mechanical properties could lead to better osseointegration for successful dental implants.
Conflict of Interests
The authors declare that there is no conflict of interests regarding the publication of this paper.
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redpajama_set_name: RedPajamaCommonCrawl


text:
/**
 * Created by peak on 15/11/14.
 */
exports.install = function (Vue, options) {

    options = options || {}
    var buildInMethods = Vue.util.extend(require("./methods.js"), processMethod(options.methods))
    var namespace = options.namespace || "verify"
    var util = require("./util.js")

    Vue.mixin({
        data: function () {
            var obj = {}
            obj[namespace] = {}
            return obj
        }
    })

    var vm = null
    Vue.prototype.$verify = function (rules) {
        vm = this
        var verifier = vm.$options.verifier || {}
        var methods = Vue.util.extend(processMethod(verifier.methods), buildInMethods)
        var verifyObj = vm[namespace]

        Vue.set(verifyObj, "$dirty", false)
        Vue.set(verifyObj, "$valid", false)
        Vue.set(verifyObj, "$rules", rules)

        Object.keys(rules).forEach(function (modelPath) {
            var model = getVerifyModel(modelPath)
            Vue.set(model, "$dirty", false)
            verify(modelPath, util.getModel(vm, modelPath))
        })

        Object.keys(rules).forEach(function (modelPath) {
            vm.$watch(modelPath, function (val) {
                var model = getVerifyModel(modelPath)
                Vue.set(model, "$dirty", true)
                Vue.set(verifyObj, "$dirty", true)
                verify(modelPath, val)
            })
        })

        function getVerifyModel(modelPath) {
            var arr = modelPath.split(".")
            var model = verifyObj[arr[0]]
            if (!model) {
                model = {}
                Vue.set(verifyObj, arr[0], {})
            }
            for (var i = 1; i < arr.length; i++) {
                if (!arr[i]) {
                    continue
                }
                var m = model[arr[i]]
                if (!m) {
                    m = {}
                    Vue.set(model, arr[i], m)
                }
                model = m
            }
            return model
        }

        function verify(modelPath, val) {
            var ruleMap = rules[modelPath]

            if (!ruleMap.required && !methods.required.fn(val)) {
                //if model not required and value is blank,make it valid
                Object.keys(ruleMap).forEach(function (rule) {
                    if (methods.hasOwnProperty(rule)) {
                        update(modelPath, rule, false)
                    }
                })
                return
            }

            var keys = Object.keys(ruleMap).sort(function (a, b) {
                var m1 = methods[a]
                var m2 = methods[b]
                var p1 = m1 ? m1.priority : 100
                var p2 = m2 ? m2.priority : 100
                return p1 - p2
            })

            stepVerify(modelPath, ruleMap, keys, 0, val)
        }

        function stepVerify(modelPath, ruleMap, keys, index, val) {
            if (index >= keys.length) {
                return
            }
            var rule = keys[index]
            if (!rule) {
                return
            }
            if (!methods.hasOwnProperty(rule)) {
                console.warn("can not find verify method of rule \"" + rule + "\"")
                return
            }
            var arg = ruleMap[rule]
            var verifyFn = methods[rule].fn
            var result = verifyFn.call(vm, val, arg)

            if (typeof result === "boolean") {
                update(modelPath, rule, !result)
                if (result) {
                    stepVerify(modelPath, ruleMap, keys, index + 1, val)
                }
                return
            }
            //promise
            else if (result instanceof Function) {
                var Promise = require("promiz")
                new Promise(result).then(function () {
                    update(modelPath, rule, false)
                    stepVerify(modelPath, ruleMap, keys, index + 1, val)
                }, function (reason) {
                    update(modelPath, rule, true)
                })
            } else {
                throw "unsupported returned value of the verify method \"" + rule + "\""
            }

        }

        function update(modelPath, rule, inValid) {
            var verifyModel = getVerifyModel(modelPath)
            Vue.set(verifyModel, rule, inValid)

            var modelValid = true
            Object.keys(verifyModel).forEach(function (prop) {
                //ignore $dirty and $valid
                if ("$dirty" === prop || "$valid" === prop) {
                    return
                }
                //keep only one rule has invalid flag
                if (!modelValid) {
                    Vue.set(verifyModel, prop, false)
                } else if (verifyModel[prop]) {
                    modelValid = false
                }
            })

            Vue.set(verifyModel, "$valid", modelValid)

            //verify.$valid
            var valid = true
            var keys = Object.keys(rules)
            for (var i = 0; i < keys.length; i++) {
                var model = getVerifyModel(keys[i])
                if (!model.$valid) {
                    valid = false
                    break
                }
            }
            Vue.set(verifyObj, "$valid", valid)
        }
    }

    Vue.prototype.$verifyReset = function () {
        var verify = this[namespace]

        var rules = verify.$rules
        if (rules) {
            vm.$verify(rules)
        }
    }

    function processMethod(methods) {
        if (!methods) {
            return {}
        }

        function process(method) {
            if (!method) {
                return null
            }
            if (typeof method === 'function') {
                return {priority: 100, fn: method}
            }

            // Vue.util.isObject is vue internal medthod, you should't use
            if (typeof method !== 'object') {
                return null
            }
            if (typeof method.fn != "function") {
                return null
            }
            var priority = method.priority
            if (!priority) {
                return {priority: 100, fn: method.fn}
            }
            if (typeof priority != 'number' || priority < 1 || priority > 100) {
                return null
            }
            return {priority: priority, fn: method.fn}

        }

        var result = {}
        Object.keys(methods).forEach(function (key) {
            var value = methods[key]
            var method = process(value)
            if (!method) {
                console.log("can not accept method \"" + key + "\"", value)
                throw "can not accept method \"" + key + "\""
            } else {
                result[key] = method
            }
        })
        return result
    }

}

redpajama_set_name: RedPajamaGithub


text:
package diablo2015;

/**
 * An interface that defines an object that is able to be periodically invoked.
 * More precisely, this interface defines an object that has a method, 'tick'.
 * Such objects are able to be added to the list of Tickable objects in
 * {@link Robot} so that its tick method will be called periodically.
 * @author Dylan Frese
 */
public interface Tickable {
    /**
     * 'Ticks' this object. This method must be overrided in classes which
     * implement this interface to provide some method that would be reasonable
     * to periodically invoke. This method should not take a large amount of
     * time, such that it does not delay other tasks, and should not wait for
     * other tasks to be complete.
     */
    public void tick();
}


text:
Q: Twilio: Received an 'hangup' event warning Salutations, community.
I have what I think is rather simple question to twilio experts.
I have a flow, which starts with an API call and proceeds as follows:

*

*Make outgoing call

*Split based on ... (call status)

*Run function

I notice periodic warnings in the Debugger with the following content:
Received an 'hangup' event while processing the 'Ended' widget for Execution Sid -X- and Flow Sid -Y-. Ignoring this event and not transitioning to another widget.
Below there are couple of causes and resolutions, which led me to believe that the issue in my particular scenario could be that 'An event came in while processing a widget that cannot handle that event (e.g. incoming message received during Run Function widget)'. Possible solutions prescribe that I must 'Return results for Function calls and HTTP requests quickly', but since the function call happens after the outgoing call, it doesn't seem I can always return from the function before this call ends and the 'hungup' event occurs.
Would love to hear ideas. While this behaviour doesn't cause any issues, seeing this erroneous (-ish) behaviour makes my eye twitch a bit.
Thanks.

redpajama_set_name: RedPajamaStackExchange


The United States Hockey League today announced the weekly award winners for the 25th week of the 2011-12 USHL regular season.
Award winners include forward Vince Hinostroza of the Waterloo Black Hawks, named recipient of CCM Offensive Player of the Week; defenseman Mike Matheson of the Dubuque Fighting Saints, selected as CCM Defensive Player of the Week; and Adam Wilcox of the Tri-City Storm who earned Reebok Goaltender of the Week.
Hinostroza scored six points (5g, 1a) and posted a plus-five rating over two victories for the Black Hawks. He netted the first goal of the game less than three minutes into the contest of Friday's 6-5 overtime win against Youngstown. The 17-year-old then had a career night scoring four goals and dishing out an assist in Saturday' 8-3 victory over Dubuque. After scoring early in the second period, he scored three consecutive goals in the third period to record the second four-goal game in the USHL this season. The big night came almost exactly a year after John Siemer scored four goals for Waterloo on March 23rd, 2011. Hinostroza is a native of Bartlett, Illinois and is currently third on the team in scoring with 35 points (14g, 21a) in 45 games.
Matheson collected three points (2g, 1a) over three games for the Fighting Saints. The defenseman scored a goal and dished out an assist in Thursday's 4-1 win over Team USA. He also equaled a season high when he finished the contest with a plus-three rating. Matheson completed the weekend scoring his ninth goal of the season in Saturday's loss to Waterloo. He also helped the Saints successfully deny 12-of-13 opponent power play chances during the three-game stretch. The 18-year-old from Pointe-Claire, Quebec has put up 22 points (9g, 13a) in 45 games during his first USHL season. A top prospect for the 2012 NHL Draft, Matheson is tied for third among all League defensemen with nine goals.
Wilcox posted a 1.00 goals-against-average and .973 save percentage as the Storm completed a two-game weekend sweep of Fargo. He stopped 36 shots in Friday's 5-1 win and again made 36 saves in Saturday's 2-1 victory. The 19-year-old from South St. Paul, Minnesota has won 21 games this season, ranking sixth among USHL goaltenders. Fourteen of those wins have come in a Storm uniform after being acquired by the team earlier in the season. Wilcox currently holds a .915 SV% which is tied for the third best mark in the League. He was selected in the 2011 NHL Draft by the Tampa Bay Lightning following his first USHL season.