Type 2 Diabetes is an example of a metabolic disorder. This disease is caused by high blood sugar and a relative lack of insulin substances in the body system of an individual. This paper provides an analysis of the development of type 2 diabetes in United States, and compares it, to the development of this medical condition in developing countries. Furthermore, this paper gives a comparison of the rates of the development of type 2 diabetes, with that of the state of Texas. This paper would also analyze the costs of treating T2D in the state of Texas. It also identifies five steps that can be used for purposes of addressing the psychosocial proliferation of type 2 diabetes. This paper also identifies six suggestions that can be used to address T2D, and provide a recommendation of one, which is the most important. This paper takes a stand that type 2 diabetes is manageable and preventable.

Type 2 diabetes is the most prevalent diabetes illness in the United States, accounting for 90% of all reported cases. In the United States, approximately 29.1 million people are suffering from T2D, and 8.1 million of them are not aware of this condition, or they are undiagnosed. In adults, people who are more than 20 years old, one out of every 10 people are suffering from diabetes (Thomas, 2013). While people who are over 65 years old, one out of every four people are suffering from diabetes. In the year 2012, 1.7 million people were reportedly diagnosed by T2D diabetes in the United States, and the trend is on the increase.

Lifestyle conditions are some of the methods that have the capability of causing an increase in diabetes, amongst the people living in United States. However, these can be eliminated with effort and time. As of the year 2012, diagnosis of diabetes was able to cost United States an approximate figure of about 245 billion dollars, and this figure is on the increase (Thomas, 2013). This is mainly because there is a yearly increase in the number of people who are diagnosed by diabetes type 2. Thomas (2013) explains that men are very vulnerable in developing diabetes type 2. However, excess weight, physical inactivity, age, poor diet and family history play a significant role in the development of diabetes type 2.

This is in the United States. In supporting these facts, Thomas (2013) provides an examination of the fasting glucose level in the United States. In the results of this study, 35% of the adults found in United States were considered to be pre-diabetic. These are people who were over 20 years old. Furthermore, 50% of the people who are more than 65 years old are pre-diabetic. By looking at these statistics, it is possible to denote that age plays an important role in determining whether an individual would become diabetic or not. This is because the rate of suffering from diabetes increases when an individual gets older.

However, it is important to explain that the number of children diagnosed for diabetes type 2 is on the increase. An explanation to this is the rise of overweight children in United States, because of the easy accessibility of unhealthy food substances. The reason why men are vulnerable to T2D is based on their lifestyle, as opposed to their gender differences. In providing a statistics on the development and prevalence of diabetes type 2 in United States, Thomas (2013) explains that children who are less than 10 years old, their rate of acquiring type 2 diabetes was 0.8 for every 100,000 people. This is between 2008, to 2014. Furthermore, amongst young people, who are between ages 10 to 19 years, their rate of new infections stood at 11 cases, for every 100,000 people.

This is an indication that age plays an important role in making an individual to be vulnerable to type 2 diabetes. In as much as genetics, age and lifestyle factors play a role in making an individual to acquire type 2 diabetes, ethnicity and racial groups also have a high prevalence rate of type 2 diabetes in United States (Thomas, 2013). T2D is common amongst African Americans, Asian Americans, Hispanics, and Native Americans, when compared to the Caucasians. The non-Hispanic blacks are people who are most vulnerable to T2D, and their rate stands at 13.2% riskier, when compared to Caucasians, or non-Hispanic white. The Hispanics have a rate of 12.8%, when compared to the Caucasians, while the Asian Americans are vulnerable by 9% (Thomas, 2013).

However, the people who are highly vulnerable to T2D are the American Indians, with one out of every three people, being diagnosed with T2D. Thomas (2013) explains that this is the highest case of vulnerability in the world. In Texas, T2D affects 13% of the entire population. This figure stands at 1.8 million people. Furthermore, the estimated number of people who are undiagnosed for T2D is 440,468 people. At the Bexar County, found in Texas, the number of people who were found to be with T2D was 137,009 people. In regard to race and ethnicity, the prevalence rate amongst the American Indians was 15.9% (Thomas, 2013). This was the highest in terms of ethnic or racial groups. The rate of prevalence amongst the non-Hispanic blacks was 13.2%, while that of the Hispanics stood at 12.8%. The treatment of diabetes in Texas is cheap, and this is because it is widely covered under Medicaid program.

This means that the government and the patient would share on the costs of treating the disease. These costs could range from hundreds of dollars, to thousands of it, depending on the stage in which an individual suffering from T2D diabetes is on. These figures are the same, when compared to the rates of T2D diabetes in the United States. In the developing countries, the prevalence of T2D is very high. Barnett (2011) explains that in every five people, one is diagnosed with T2D the developing countries. Some of the reasons identified for the high rate of T2D diabetes in developing countries is based on the fact that people are poor, and they are unable to afford high quality and nutritious foods, and proper medical services.

People suffering from T2D normally pass through a series of psychosocial problems, and these include depression, anxiety, withdrawal from people, etc. For purposes of changing the behavior of these people, there is a need of following these steps (Thomas, 2013),

• Construction of the definition problem.
• Setting of a collaborative goal.
• Collaborating to solve the problem.
• Contracting changes
• Continuing support.

The first step involves the identification of the problems suffered by the patient. It is difficult to come up with a psychosocial approach, without having knowledge on the problems that they suffer (Barnett, 2011). The second stage involves creating a common goal, that needs to be pursued for purposes of helping a patient, and the third stage is collaborating with each other, for purposes of coming up with a solution of helping the patient overcome his or her psychosocial problems.

In solving the problems, changes must occur; therefore the fourth step involves analysis of those changes, for purposes of identifying if they are effective in helping the patient. The fifth step is a follow up, which involves visiting the patients for purposes of determining whether they are able to overcome their psychosocial problems. For purposes of addressing T2D in my previous environment, there is a need of following the following steps (Shallenberger, 2006),

• Identification of the causes of T2D.
• Educating people on the causes and impacts of T2D.
• Encouraging the medical screening of employees
• Offering counseling sessions to anyone suffering from T2D.
• Prevention of food substances that can make it riskier for employees to acquire T2D.
• Offering to treat anybody suffering from T2D, and this should be a motivational policy.

Of these steps, the best step in addressing issues touching on T2D is the identification of its causes. This is because it would make people to be careful and avoid living a lifestyle that can make them vulnerable in the acquisition of this type of disease.

In conclusion, with proper policies and strategies, it is possible to manage T2D. All that is needed is to educate the people on the dangers of this disease, and its causes. Once this is done, there is a need of encouraging the people to stop the behaviors that could lead to the emergence of this problem.

References:

Top of Form

Barnett, A. H. (2011).

Type 2 diabetes

. Oxford: Oxford University Press.

Bottom of Form

Top of Form

Thomas, M. (2013).

Understanding type 2 diabetes: Fewer highs fewer lows better health

.

Wollombi, N.S.W: Exisle Publishing.

Bottom of Form

Top of Form

Shallenberger, F. (2006).

The Type 2 diabetes breakthrough: A revolutionary approach to

treating Type 2 diabetes

. Laguna Beach, CA: Basic Health Publications.

Bottom of Form

Thomas, a 70-year-old man, admitted to hospital with a five-day history of coughing with yellow-green sputum, pyrexia, rigors, poor appetite, mild chest pain and increasing difficulty of breathing.

The initial observations are:

Neurological: Altered neurological status, GCS 11/15. Agitated and confused.

Cardiovascular: Sinus tachycardia, HR 135bpm. Hypotension, 90/45 mmHg.

Respiratory: Tachypnoeic, RR 35bpm. Decreased saturation while receiving 6L O2 through Hudson mask.

Metabolic: Febrile, 39 degree

Renal: Oliguric with 20ml/hr urine output. Indwelling catheter (IDC) was inserted.

The blood test revealed that the patient was suffering from hypernatremia, hyperkalaemia, hyperglycaemia, elevated urea, poor creatinine, increased WCC and low platelet count. The ABG indicated that Thomas was experiencing combined respiratory and metabolic acidosis. Thomas was finally diagnosed as sepsis complicated by the right middle lobe streptococcus pneumonia. He required intubation and invasive ventilation support.

In this case study, the pathophysiology of sepsis will be discussed and the mechanism of synchronised intermittent mandatory ventilation (SIMV) volume control ventilation mode will be explained.

Sepsis is defined as the dysregulated inflammatory response caused by severe infection (Neviere 2015). It has the interchangeable definition as Systemic inflammatory response syndrome (SIRS) while the SIRS is resulted by a suspected or confirmed infectious source (Neviere 2015). The concept of SIRS was first introduced by the American College of Chest Physicians (ACCP) and Society of Critical Care Medicine (SCCM) in 1992 (Kaplan 2014). It is characterised by two or more following symptoms. They are fever of high than 38 degree or hypothermia; tachycardia; tachypnoea or partial pressure of arterial carbon dioxide (PaCO2) less than 32 mmHg; deranged white cell count of more than 12,000/µL or less than 4,000/µL (O’brien et al. 2007). Associated with Thomas’s symptoms, it is clear to see that he was definitely experiencing sepsis. It is because that he was febrile up to 39 degree, tachycardic with heart rate of 135 bpm, and had increased respiratory rate of 35bpm as well as the elevated leucocytes count of 14,000 per microliter. The clinical signs are related to the inflammation process which is activated by the body immune system. Due to the severe infection, a large number of proinflammatory mediators are released which in turn result in the serial inflammatory reaction and extensive tissue damage (Neivere 2015). It is reported that SIRS can lead to high mortality rate because of high occurrence of SIRS induced multiple organ dysfunction syndrome (MODS) (Singh et al. 2009). In the following paragraphs, the pathophysiology of sepsis/SIRS will be more comprehensively examined.

The pathophysiology of SIRS is complex. There are a few elements that need to be emphasised. They are acute stress response, inflammatory process and cytokine storm.

Firstly, stress response is the acute phrase reaction when the body tries to defence against the threatening triggers. Those triggers are also known as ‘stress’. Stress can be caused by daily life events, environmental factors or physical illness (Better Health Channel 2012). In Thomas’s case, the stress response is initiated by infection.

Under the influence of stress, the body steady state is disrupted. To maintain the homeostasis, the stress response is activated to reverse the body balance and redistribute the oxygen and energy to maintain the function of vital organs (Kyrou et al. 2012). Hypothalamus plays a vital role in processing the distress signals (Seaward 2015). Once it senses the stress, it triggers the activation of sympathetic nervous system. The sympathetic nervous system then stimulates the adrenal gland to produce epinephrine. It is also known as adrenaline. The adrenaline can lead to increased heart rate and myocardial contractility; dilated pupils and bronchi; peripheral vasoconstriction; accelerated respiratory rate; decreased digestive activity and increased production of glucose from liver (Seaward 2015).

In addition, stress can also activate another pathway of stress response. That is the hypothalamic-pituitary-adrenal (HPA) axis (Seaward 2015). It means the stress triggers the release of corticotrophin-releasing factor (CRF) from anterior hypothalamus. The CRF then promotes the pituitary gland to produce adrenocorticoid trophic hormone (ACTH). The ACTH stimulates the production of cortisol and aldosterone through the adrenal cortex. Those corticosteroids can result in increased metabolism, sodium and water retention (Seaward 2015).

Therefore, it is obvious that Thomas was under the effect of stress. He was tachycardic, tachypnoeic and slightly hyperglycaemic due to the effect of sympathetic nervous response. He was oliguric because of the acute kidney injury secondary to the vasoconstriction. His hypernatremia status can be contributed by the impact of aldosterone. He had poor oral intake can be cause by the suppressed digestion function.

Secondly, the inflammatory cascade plays an essential role in the pathophysiology of systemic inflammatory response syndrome. Sagy et al. (2013) summarised the inflammation mediator related mechanisms in the systemic inflammatory response. It is indicated that the excessive release of pro-inflammatory mediators result in the inflammation, inhibit the function of compensatory anti-inflammatory response, and compromise the immune system eventually (Sagy et al. 2013).

Cytokines are the essential components of immune system. Bone et al. (1992) explained that the local cytokines are activated immediately after an insult in order to repair the wound and initiate the innate immune system. Because of the release of local cytokines, a small amount of cytokines go into the circulation. This promotes the production of growth factor and adhesion of macrophages and platelets to help with the recovery of the local damage. However, when the infection is severe and the homeostasis is unable to be restored, cytokine storm occurs.

More specifically, cytokine storm is formed from a complex progression. Cytokines are made up by macrophages, monocytes, mast cells, platelets and endothelial cells, which are the initial immune defensive components (Plevkova 2011). The multitude of cytokines can soon induce the cytokine tissue necrosis factor-alpha (TNF-a) and interleukin-1 (IL-1). Those two elements result in the removal of nuclear factor-KB (NF-KB) inhibitor. This in turn prompts the production of more proinflammatory mediators, such as IL-6, IL8 and interferon gamma (Plevkova 2011). In other words, cytokines stimulate the production of immune cells, which in turn induce more cytokines in the circulation.

The cytokines have a great impact on the body, including direct or indirect contribution of mortality in SIRS. TNFa is discovered causing fever, abnormal haemodynamic values, low white cell count, increased liver enzymes and clotting problems (Jaffer et al. 2010). IL-1 is reported having connection with fever, haemodynamic abnormality, loss of appetite, general weakness, headache and neutrophilia (Jaffer et al. 2010). IL-6 is found having strong relationship with fever and impaired lung function as well as acting a determinant of severity of SIRS and mortality rate (Jaffer et al. 2010). The massive accumulation of cytokines can cause widespreading vasodilatory effect. It is because the cytokines stimulate the release of vasodilators such as nitric oxide (Sprague and Khalil 2009). Additionally, cytokines promotes adhesion of the immune cells and the endothelial cells, which in turn leads to leaky endothelium and loss of fluid from intercellular space to extracellular space (Sprague and Khalil 2009). Moreover, the cytokines cascade can also lead to the clotting disorder. It is because of the high concentration of fibrinogen in the inflammation process (Esmon 2005). The fibrinogen is converted from thrombin, which is generated by tissue factor. Tissue factor is a substance that is expressed by the surface of white cell. It can also be induced by TNFa and endotoxin from the infection (Esmon 2005). The fibrinogen can be transferred into fibrin which in turn forms clots. As the excessive amount of fibrin in the inflammation status, it can result in extensive clotting disorder.

To sum it up, it can be concluded that Thomas’s fever is highly likely related to the release of TNFa, IL-1 and IL-6. IL-1 could be one of the contributors of his poor appetite and elevated white cell count. IL-6 could worsen Thomas’s existing affected lung function. Thomas had increased white cell count can be contributed by the immune response and IL-1. The hypotension is related to the vasodilation effect. Due to the hypotensive, the kidney perfusion dropped and then led to the acute kidney failure and poor urine output. The acute kidney injury may affect the elimination of potassium so that Thomas was found having high potassium level. The low platelet count could be related to the massive production of cytokines and damaged endothelium.

In the next section, the synchronised intermittent mandatory ventilation volume control will be explained as Thomas’s mechanical ventilation management.

The synchronised intermittent mandatory ventilation (SIMV) is commonly used in ICU. With the volume control mode, the patient is given the ventilation support with a set tidal volume during the mandatory breaths (Deden 2010). To provide the effective ventilation support, there are a few specific values that need to be set up for the SIMV volume controlled mode. They are tidal volume and respiratory rate. The tidal volume refers to the amount of oxygen delivered by the ventilator or the amount of oxygen the patient breathes voluntarily. The respiratory rate is set up for mandatory breaths. In the SIMV volume controlled mode, the ventilation is trigger by the ventilator or patient self. It means the actual respiratory rate can be upon the preset rate (Goldsworthy and Graham 2014). There is a window of time for the ventilator to sense the patient’s inspiratory effort. This trigger window helps avoid the ventilator deliver the oxygen when the patient exhales (Deden 2010). If the patient is able to trigger the ventilation within the time frame, the patient-triggered mandatory breath is induced. After reaching the demand tidal volume, the inspiratory phrase ends and expiratory starts. Between each mandatory breaths, the patient is able to initial own spontaneous breath, the breathing volume and length depend on the patient’s respiratory effort (Pierce 2007). If the patient is heavily sedated and unable to initiate the spontaneous breath within the trigger window, the machine-triggered mandatory breath will be activated to provide constant ventilation support according to the set respiratory rate and tidal volume (Deden 2010). Once the ventilator delivers the demand tidal volume, the inspiratory cycle ends and expiratory phrase starts until the next scheduled inspiratory cycle. If the patient’s attempt of breathing is not strong enough to trigger the patient-triggered mandatory breath, the assisted synchronised breath will be provided to achieve the desired the tidal volume. Like the other mode, the inspiratory cycle ends once the set tidal volume is delivered (Deden 2010).

It is believed that Thomas would be beneficial from the SIMV volume controlled mode. It is because that SIMV mode could help him reduce the work of breathing, especially when he was in the high energy-consuming septic status. In addition, due to the SIMV mode, the ventilator allows him to have extra breath to blow off the accumulative carbon dioxide. This can improve his acidosis. Moreover, because of the systemic inflammatory response syndrome and severe pneumonia, his lungs could be stiff and fragile secondary to the inflammation effect and accumulation of cytokines. The volume controlled ventilation acts as a protective strategy to avoid the ventilator related complications, such as volutrauma. It is recommended not to set the tidal volume more than 8-10ml/kg (Deden 2010).

In conclusion, sepsis is a systemic inflammatory response syndrome resulted by the infection. The stress response, inflammation reaction and cytokines play essential roles in the progression of SIRS. As SIRS can cause high mortality rate, it is vital to control the infection and manage the widespreading inflammation as well as providing appropriate support to treat the symptoms. In Thomas’s case, the volume controlled synchronised intermittent mandatory ventilation would be the better option of managing his severe pneumonia and respiratory distress.

Reference

Better Health Channel 2012,

Stress

, viewed 12th March 2015,

http://www.betterhealth.vic.gov.au/bhcv2/bhcarticles.nsf/pages/stress

Bone, RC, Balk, RA, Cerra, FB, Dellinger, RP, Fein, AM, Knaus, WA, Schein, RM & Sibbald, WJ 1992, ‘Definitions for sepsis and organ failure and guidelines for the use of innovative therapies in sepsis. The ACCP/SCCM Consensus Conference Committee. American College of Chest Physicians/Society of Critical Care Medicine’,

Chest

, vol. 101, no. 6, pp. 1644-1655.

Deden, K, 2010, Ventilation modes in intensive care, Dragerwerk AG & C0. KGaA, Germany

Esmon, CT 2005, ‘The interactions between inflammation and coaulation’, British Journal of Haematology, vol. 131, no. 4, pp. 417-430.

Goldsworthy, S & Graham, L 2014, Compact Clinical Guide To Mechanical Ventilation : Foundations Of Practice For Critical Care Nurses, New York, NY

Jaffer, U, Wade, RG & Gourlay, T 2010, ‘Cytokine in the systemic inflammatory response syndrome: a review’, HSR Proceedings in Intensive Care & Cardiovascular Anaesthesia, vol. 2, no.3, pp. 161-175.

Kaplan, LJ 2014, Systemic inflammatory response syndrome, viewed 19th March 2015,

http://emedicine.medscape.com/article/168943-overview#a0101

Kyrou, I, Chrousos, Kassi, E & Tsigos, C 2012,

Stress, Endocrine physiology and pathophysiology

, viewed 12th March 2015,

Stress: Endocrine Physiology and Pathophysiology

Neviere, R 2015, Sepsis and the systemic inflammatory response syndrome: Definition, epidemiology and prognosis, viewed 19th March 2015,

http://www.uptodate.com/contents/sepsis-and-the-systemic-inflammatory-response-syndrome-definitions-epidemiology-and-prognosis

O’brien, JM, Ali, NA, Aberegg, SK & Abraham, E 2007, ‘Sepsis’,

The American Journal of Medicine

, vol.120, no.12, 1012-1022.

Pierce, LNB 2007, Management of Mechanically Ventilated Patient, 2nd edn, Saunders Elsevier, London

Plevkova, J 2011, Systemic inflammatory response syndrome, viewed 24th March 2015,

http://eng.jfmed.uniba.sk/fileadmin/user_upload/editors/PatFyz_Files/Handouty/angl/Systemic_inflammatory_response_syndrome_2011.pdf

Sagy, M, Al-Qaqaa, Y & Kim, P 2013, ‘Definitions and pathophysiology of sepsis, Current Problems in Paediatric and Adolescent Health Care, vol. 43, no. 10, pp. 260-263.

Seaward, BL 2015, ‘Physiology of stress’,

Managing Stress

, Jones & Bartlett Learning, Burlington, MA.

Singh, S, Singh, P & Singh, G 2009, ‘Systemic inflammatory response syndrome outcome in surgical patients’,

Indian Journal of Surgery

, vol.71, no.4, pp. 206-209.

Sprague, AH & Khalil RA 2009, ‘Inflammatory cytokines in vascular dysfunction and vascular disease’,

Biochemical Pharmacology

, vol. 78, no. 6, pp. 539-552.

1

Ying Hu 76898

Material’s Need

Dental health is

very

important in order to maintain a healthy lifestyle. Issues with bacteria in the mouth due to cavities and other infections or ailments have been linked to severe long-term illnesses such as Alzheimer’s (Dominy, Stephen). “…a condition such as gingivitis, which is an inflammation of the gingival complex, will cause sensitivity, swelling and pain in the gums. If left untreated, it will begin to affect the underlying bone and can eventually cause the teeth to loosen, a condition known as periodontitis [6]. Conditions such as the two aforementioned are common, and the percentage of population with decayed or missing teeth is particularly high…” (Grech, Johnathan).

Solutions to these oral ailments include dental implants, which commonly use metals like titanium. Titanium is a biocompatible metal however it does not operate in concert aesthetically with the color palette of the mouth. Additionally, the immunocompromised and those with titanium allergies are not always able to use titanium and require cost effective and safe alternatives. A safe alternative solution to the tantalizing titanium topic is the use of zirconia-based ceramics for dental implants. The ceramic is much closer to the actual color of teeth; not to mention “…their superior strength and fracture toughness when compared to metallic alternatives such as pure titanium…”(Grech, Jonathan).

Industries around the world continue to find solutions to an ever-expanding list of problems, the catch being that once a solution is found, it is sometimes difficult to improve upon it. In the case of the dental industry, the long-standing solution to dental problems that require implants is to use titanium alloys. Titanium alloys have been enormously successful as the implant material of choice for patients whose conditions require it; and the procedural results can last throughout the life of the patient. The manufacturing process for the material begins with “zirconia” – a zirconium oxide ceramic, doped with yttria- which will be discussed in more detail in the following sections. While it would be incorrect to simply state that using zirconia is undoubtedly an improvement in

every

case, it is an option that garners some consideration, since there are cases where titanium isn’t a viable option. On the sparse chance that an individual has an allergy to nickel -a component in titanium alloy implants- the patient would experience untoward effects from the procedure. Patients with auto-immune diseases are at further risk of health complications due to the inability to counter the dispersion of titanium throughout the body. Another potential complication arises from galvanic toxicity which occurs when a metal reacts with the enzymes in saliva and can cause a metallic taste in the mouth or even chronic insomnia (Baylin, Michael)

Specific Material in mind

Yttria stabilized zirconia is the particular ceramic of focus due to its unique properties. These properties make it an ideal orthodontal prosthetic. One company lists the material properties of their particular ‘flavor’[manufactured version] of the material. The data for which is displayed in table 1. As can be seen in columns three and four, the materials’ colors are listed as ‘Ivory’. Additionally, the compressive strength of the ‘YZTP 4000 & 2000 Yttria Stabilized Zirconia’ is among the highest of the above listed at about 2485 MPa (where 1 Megapascal = 103 Pa). This is yet another reason to use it as a dental implant due to the magnitude of masticatory forces.

Atomic Bonding and structure of specific material

Ceramics typically have ionocovalent bonding, which gives them the myriad of properties that separate them from other compounds such as metallic compounds for example. The ionic bonds in ceramics have high bond energies, require large differences in electronegativity between the atoms, and are non-directional in nature. While the covalent bonds in ceramics have high bond energies, small to no differences in electronegativity, and directional bonding. These two bonding types working in concert are what contribute to the properties of ceramics such as toughness, hardness, brittleness, and resistance to wear & decomposition due to stability of the chemical structure. Of the two, since zirconium has an electronegativity of about 1.3 Pauling Units and Oxygen has an electronegativity value of about 3.4 Pauling units, the electronegativity difference between the two is enough to determine that the atomic bonding of zirconia is predominantly ionic (Callister, William D.). The seven crystal lattice system groups stemming from the 14 Bravais lattices include: Cubic, Hexagonal, Tetragonal, Rhombohedral, Orthorhombic, Monoclinic, and Triclinic (Callister, William D.). Of these seven, the most commonly found is intuitively going to be closest to room temperature [outside temperature] because most [uncontrolled] reactions are going to veer towards room temperature; according to figure 2, this is the monoclinic structure. For dental applications, however, the tetragonal structure is the most effective because of the unique property of stress induced transformation toughening. This allows for the implant to be cracked and damaged, because the more dense tetragonal structure will break and cause the structure surrounding the crack to form a less dense monoclinic structure and halt the crack propagation(Superior Technical Ceramics, & Caster, William D.).

Depicted in figure 1 is the demonstration of the above discussed “BONDING IN CERAMICS[which] is both ionic (top) and covalent (bottom). In ionic bonding electrons are transferred from an atom to a neighboring one. The donor atom thereby becomes positively charged and the acceptor atom becomes negatively charged. The electrostatic force between the atoms keeps the atoms in place. In covalent bonding electrons are shared more or less equally between neighboring atoms. Unlike ionic bonds, covalent bonds (represented here by visible connections between atoms) tend to be highly directional and resist the sliding of planes of atoms past one another. The diagrams are idealized cases. An actual ceramic has a hybrid of the two bonds among its constituent atoms” (Bowen, Kent H.).

Phase Diagram of selected material

Phase diagrams for materials [specifically metals] typically will depict the eutectic -liquid to 2 solid phases-, eutectoid -solid to 2 solid phases- , peritectic -liquid + 1 solid phase to another solid phase-, and peritectoid -2 solid phases to 1 solid phase- reactions; however, this one is more useful for understanding the atomic structures of the material and the temperatures at which the desired tetragonal phase forms. An example that shows the melting point and liquid phase can be seen in figure 3. As previously mentioned, the tetragonal structure is the one of interest. This phase is most reliably present at approximately 1200 C and 1.5 % moles of YO1.5 (Witz, Gregorie).

Figure 3 depicts Yittrium Tantalate phase diagram with zirconia with particular structures, phases, and temperatures clearly labeled as well as the rough percentage of ZrO2 moles present. It should be noted that this is a different material that zirconia is being doped with, and it will have slightly different physical properties because of this [hence the difference in melting temperature].

Predict Microstructure, strengthening mechanisms, and mechanical properties

The manufacturing process for “Yttria-stabilized zirconia (YSZ)…” begins with the specimen “…produced as a tetragonal metastable polymorph containing around 7%–8% weight of yttria” which can be varied to obtain the desired microstructure (Witz,Gregoire). For dental applications, a tetragonal and monoclinic structure is desired so that the stress induced transformation toughening property can be exhibited by the material. To achieve these structures, it is “…shown in Fig. 1[The phase diagram labeled figure 2], [that] other polymorphs of YSZ can be obtained by varying the yttria content. YSZ is stabilized into its cubic form by a high yttria content; monoclinic YSZ, on the other hand, forms with low yttria contents. The monoclinic polymorph is stable only at low temperatures and undergoes a martensitic transformation to a tetragonal phase around 1000 [degrees Celsius]. The monoclinic-to-tetragonal transformation causes a volume change in the unit cell by about 4%, which can result in cracking and coating failure” (Witz, Gregoire).

The aforementioned transformation is the ‘stress induced transformation toughening’ discussed above which is the unique property that makes this material ideal for dental applications. This occurs in materials that have tetragonal and monoclinic structure. It allows for “a crack in a ceramic [to be] arrested…” which is a benefit of “new processing techniques that seek to eliminate crack-initiating imperfections. Transformation toughening (left[of figure 4]) relies on a change in crystal structure (from tetragonal to monoclinic) that zirconia, or zirconium dioxide (ZrO,), grains undergo when they are subjected to stresses at a crack tip. Because the monoclinic grains have a slightly larger volume, they can “squeeze” a crack shut as they expand in the course of transformation. Ceramics can also be made crack-resistant by interlacing with fine ceramic fibers (middle), as is the case in composite materials. The fibers span a crack and keep it from becoming wider and growing. A third way to stop a crack is by spreading the stresses concentrated at its tip over a larger surface. This can be accomplished if minute cracks, called microcracks (right), are purposely created in the ceramic material during processing. When an approaching crack merges with a micro crack, its tip is blunted”(Bowen, Kent H.).

Doping is the act of adding impurities to ceramics in order to change their material properties. This can be very easily seen from the stark differences in the phase diagrams depicted as figure 2 and figure 3. The difference in structure and the difference in the melting point temperature is a direct result of doping the Zirconia with Yttria vs with Y0.5Ta0.5O2 (Gurak, Mary & Witz, Gregoire).Mechanically Speaking, as depicted in table 1, the properties of Yttria stabilized Zirconia -or Zirconia ‘doped’ with Yttria-  such as toughness, hardness, brittleness, resistance to wear & decomposition, and thermal/electrical insulation are all directly a result of the bonds and structure.

Estimated Impact on Society, including globally, economically, and environmentally, as well as occupational safety.

Introduction of foreign materials into osseous tissue has caused issues within the human body since the dawn of prosthetic development. From peg-legged pirates to myoelectric arms that gyrate, the human body is a minefield of unexpected problems stemming from even the most seemingly insignificant incompatibilities. However, the task of tackling the requirements for effective biomedical prostheses is worth the hassle because of all the possibilities the solutions offer. Dental health among the most important to upkeep because the ramifications of neglecting it can cause severe illnesses as mentioned in the ‘Materials’ Need’ section. With the integration of dental prosthetics, and the struggles that maxillofacial surgeons and dentists face, a material that will allow bone to grow onto it and diffuse into it was much needed. The main issue with the conundrum being that the material must also be biocompatible. This is where zirconia based ceramics shine [like pearly whites]. In a study conducted to test the “Bone Response to Zirconia Ceramic Implants: An Experimental Study in Rabbits”, scientists discovered that “A great quantity of newly formed bone was observed in close contact with zirconia ceramic surfaces; in some areas, many osteoblasts were present directly on the zirconia. Percentage of boneimplant contact was 68.4% 6 2.4%. Mature bone, with few marrow spaces, was present. Small actively secreting osteoblasts were present in the most coronal and apical portions of the implant. No inflamed or multinucleated cells were present. This study concluded that these implants are highly biocompatible and osteoconductive” (Scarano, Antonio). This means that the implants were successful in regenerating at least enough osseous tissue to form a secure bond between the prosthetic and the patient; such prosthetics only help aid individuals to perform more efficiently and to mesh more effectively in society, and can only positively impact such a society. Globally, zirconia is not a scarce element and can be found even in the United States; additionally, it has a stable structure that does not degrade into unstable or harmful elements but instead remains effectively chemically inert indefinitely which mitigates its environmental impact (Burke, Joseph E.). In regard to occupational safety, the medical field in the United States is so heavily regulated and highly maintained that the only occupational hazards that is related to such a material stems from any flaw in the medical procedure itself. With all of these in consideration, Zirconia stabilized by doping with Yttria and raising to approximately 1200 C with 2.5-3% molar weight YO1.5 produces the tetragonal structure which benefits from stress induced transformation toughening and is a sufficiently biocompatible material to be used as an excellent dental prosthetic.

References

1. Dominy, Stephen S. “Porphyromonas Gingivalis in Alzheimer’s Disease Brains: Evidence for Disease Causation and Treatment with Small-Molecule Inhibitors.”
   
   American Association for the Advancement of Science
   
   , 2019.
2. Grech, Jonathan. “Zirconia in dental prosthetics: a literature review”
   
   College of Science and Engineering, James Cook University, Townsville, QLD 4811, Australia
   
   , 2019
3. Superior Technical Ceramics “Transformation Toughening of YTZP How it Resists Crack Propagation”
   
   Superior Technical Ceramics
   
   2018
4. Superior Technical Ceramics “What is low Temperature Degradation and how does it affect the properties of YZTP”
   
   Superior Technical Ceramics
   
   2018
5. Superior Technical Ceramics “Materials Property Chart”
   
   Superior Technical Ceramics
   
   2018
6. Scarano, Antonio et al. “Bone Response to Zirconia Ceramic Implants: An Experimental Study in Rabbits”
   
   Ministry of Education University and research (MIUR), Rome, Italy.
   
   2019
7. Burke, Joseph E. “Ceramics Today: Ceramics made from pure substances may be controlled to have a variety of useful properties”
   
   American
   
   
   
   
   Association for the Advancement of Science.
   
   , Vol 161, Number 3847, 20th September 1968
8. Bowen, Kent H. “Advanced Ceramics: These nonmetallic, nonpolymeric materials are hard, resist heat and chemicals and can be designed to have special electrical properties. Research Focuses on a major shortcoming: a tendency to crack easily”
   
   Scientific American, A division of Nature America Inc.
   
   Vol 255, Number 4, pp 168-177, October 1986
9. Witz, Gregoire “Phase Evolution in Yttria-Stabilized Zirconia Thermal Barrier Coatings Studied by Rietveld Refinement of X-Ray Powder Diffraction Patterns”
   
   Journal of the American Ceramic Society
   
   September 2007
10. Baylin, Michael. “Dental Implants; An Integrative Perspective” 2012.
11. Gurak, Mary “On the Yttrium Tantalate – Zirconia Phase Diagram”
    
    Journal of the European Ceramic Society
    
    March 2019
12. Callister, William D. “Fundamentals of Materials Science and Engineering: An Integrated Approach 4th edition”
    
    John Wiley & Sons, Inc.
    
    2012