Given the recent rise in cosmetic dentistry over the last few years, I plan to investigate one of the most common procedures, tooth whitening. In this report, I will;

Try to discover why patients choose to have their teeth whitened and when vital tooth whitening is indicated (types of staining-extrinsic and intrinsic)

Try and find out the mechanism of tooth whitening and what the most common bleaching agents are (hydrogen peroxide and carbamide peroxide)

Explore the different ways in which tooth bleaching is carried out (take-home trays, in-office power bleaching and over the counter treatments) and which system is the most recommended according to a variety of studies

Identify the main side effects to tooth bleaching, and if this has any impact on a patient’s decision for undertaking the procedure

Draw my own conclusion, based on previously carried out clinical trials and current professional opinion, on which is the ‘best’ method to use.

Conclusion:

Tooth whitening is an effective, widely accessible method for removing stains and discolouration, which is very popular amongst patients and has minimal side effects. Of the different methods of delivery, it appears that take-home tray systems are the best, as they have the greatest efficacy and are the most tolerated by patients.

Introduction

Tooth bleaching is not a new procedure, and reportedly was in use more than a hundred years ago, using hypochloric acid to treat dental fluorosis [Khin, 2007]. Since then the technology has evolved to become more advance and specific, responding to the recent increased demand from patients for aesthetic procedures including orthodontics, ceramic crowns, tooth-coloured restorations, as well as tooth whitening. Such procedures often have little or no effect on the functionality of the dentition and are therefore often disregarded as an important dental issue by professionals, yet there is a high demand for more competitive aesthetic procedures by patients indicating that is very important to them.

According to Kershaw et al (2008), “physical appearance plays a key role in human social interaction and the smile and teeth are important features in determining the attractiveness of a face” and that more attractive people are perceived as “more popular, sociable, extraverted, sexually attractive and happy”. It therefore follows that people request whitening, as discoloured and decayed teeth are seen as associated with “lower levels of social competence, intellectual ability, psychological adjustment, and relationship satisfaction” [Kershaw et al, 2008] as well as unattractive.

An investigation by Alkhatib et al (2004) assessed people’s perception of their own teeth discolouration, and found that half the population saw themselves with some form of discolouration, with 31% rating their discolouration as ‘mild severity’. They found people’s dissatisfaction with their teeth positively correlated to their perceived discolouration and that, interestingly, females we less likely to perceive their own discolouration than males. This is perhaps because women are more aware of their physical appearance in general and so are more likely to have work done previously to correct any issues they have.

Nevertheless, it is clear that people observe tooth colour as an important dental issue. This, as well as tooth whitening being relatively, quick, inexpensive and widely accessible could explain why it is the most popular cosmetic dental treatment, and currently in such high demand. Thus, there is a wide variety of research undertaken recently, to better understand how whitening works, which are the best methods of whitening and if there are any associated risks.

Causes of tooth discolouration

The natural colour of teeth is “associated with the light scattering and adsorption properties of the enamel and dentine” [Joiner, 2006] with the dentine attributing to a greater part of the colour and the main cause for the yellowish tinge to teeth. This could explain why teeth tend to look more ‘yellow’ with age, as throughout life the quantity of dentine increases since secondary dentine is continually being laid down. Such discolouration is referred to as intrinsic staining which is due to changes within the tooth structure. As well as ageing, other intrinsic factors include metabolic diseases, systemic factors and prescriptive drug staining (figure 1) [Pretty et al, 2006]. The intrinsic factors can be incorporated into the tooth pre-erruptively (during tooth morphogenesis) or post-erruptively (after morphogenesis) [Minoux & Serfaty, 2008].

Extrinsic staining is more superficial and affects the enamel or pellicle layer on the outside of the tooth surface. It normally forms on sites where patients find it more challenging to brush, such as interproximal and lingual areas. The staining is often caused by high intake of caffeinated drinks or tannins in diet or smoking [Pretty et al, 2006]. Further causes are illustrated in figure 1. Mild extrinsic staining can sometimes be removed by shop bought products like whitening toothpastes, or can be removed professionally using ultrasonic scaling and polishing and therefore don’t always require bleaching.

The nature of the staining needs to be determined in order to select the best bleaching system and maximise the effects of the treatment, as some types of intrinsic staining will not be affected by bleaching. These are highlighted in bold in figure 1. Methods other than bleaching, such as composite or porcelain veneering, can therefore be used instead to treat the discolouration.

Types of staining

Intrinsic

Alkaptonuria

Congenital erythopoeitic prohyria

Amelogenesis Imperfecta

Dentinogenesis Imperfecta

Fluorosis

Tetracycline staining

Enamel Hypoplasia

Pulpal Heamorrhagic products

Root resorbtion

Ageing

Extrinsic ~ non-metallic

Dietary components

Tobacco

Beverages

Mouthwashes (chlorohexedine)

Extrinsic ~ metallic

Copper

Iron

Potassium permanganate

Silver nitrate salt

Stannous Fluoride

Figure 1

A table to show the different factors which could cause tooth discolouration.

[Pretty et al, 2006]

Tooth whitening- how does it work?

In vital tooth bleaching, a gel or liquid preparation is applied externally to the tooth surfaces. The contents of the preparation vary depending on the delivery system, but in general, in-office power bleaching contains hydrogen peroxide and clinician supervised take home systems contain either hydrogen peroxide (HP) or carbamide peroxide (CP), a hydrogen peroxide precursor. The HP diffuses easily into enamel and dentine due to its molecular weight, and can act from there. [Matis et al, 2009]

The nature of the exact mechanism is still not clearly understood, however it is thought that there are several likely reactions that occur, depending on what the environmental conditions are like.

In alkaline conditions, the hydrogen peroxide can undergo ionic dissociation (see equations 1 and 2, figure 2) to produce hydroxyl radicals. However, in take home tray systems where carbamide peroxide (CP) is often used, the breakdown of CP to HP when it comes into contact with water involves the production of urea, which in turn breaks down into carbon dioxide and ammonia. These products cause the pH in the tray to decrease [Minoux & Serfaty, 2008]. In these more acidic conditions, HP undergoes anionic dissociation or homolytic cleavage (equation 3, figure 2), particularly promoted by UV light or high temperatures, to produce free radicals which act as powerful oxidisers. To become more stable, the oxidative agents disrupt double bonds within organic molecules (such as carbon, oxygen and nitrogen) which act as electron donators. These double bonds are vital in molecules which generate colour in organic molecules, also known as chromophores, and when the double bond is broken it either causes a change in the size of the chromophore, therefore reducing the absorption energy of the molecule from a longer visible light wavelength to a shorter one and making the molecule appear lighter [Minoux & Serfaty, 2008] or it causes the pigment molecules to break down and diffuse out into the environment [Thickett & Cobourne, 2009].

As well as anionic dissociation, HP can also undergo photo dissociation, which is light activated. This is why in-office bleaching techniques often use light curing systems, so try to speed up the bleaching process, by producing more oxidising agents faster from HP.

1)

2)

3)

4)

5)

Figure 2

Equations 1 and 2 show ionic dissociation of hydrogen peroxide under alkaline conditions to produce hydroxyl radicals

Equation 3 show the homolytic cleavage of hydrogen peroxide under acidic conditions and the presence of UV light, producing hydroxyl radicals

Equations 4 and 5 show the chain reaction which can follow on from equation 3, producing perhydroxyl and superoxide radicals.

[Minoux & Serfaty, 2008]

Bleach delivery systems

At present, there are 3 major bleaching systems used for vital teeth; Home bleaching kits which can be bought by patients over the counter, in-office systems used by the practitioner in the surgery and clinician assisted home systems.

Home bleaching systems

These products are readily available over the counter in most pharmacies and drug stores. They are most often bought by patients who choose to have their teeth whitened but present with no obvious discolouration of their teeth and simply want a brighter and more ‘youthful’ smile to improve their facial appearance [Pretty et al, 2006]. These shop-bought whitening kits are therefore suitable for them as legally in the UK the product can only contain up to 0.1% hydrogen peroxide [Thickett & Cobourne, 2009] and so this low concentration will produce minimal effect but still remove any mild discolouration or maintain white teeth.

The delivery of the treatment varies greatly depending on the manufacturer and country, but examples include whitening strips, paint on brush applications, dentifrices and kits containing a pre-moulded tray [Brunton et al, 2006]. (For a list of different branded products available in the UK, refer to figure 3).

These products are often very affordable, but little research exists on their effectiveness. According to Li (2003), to produce the same effect as professional whitening, the products have to be used for much longer. However, as the product relies solely on patient use the risk of inappropriate use is high.

In- office bleaching systems

These products are only available in the clinic, as they contain much higher levels of peroxides and are more technique sensitive so can only be applied by a professional. The high concentration of peroxides means that this procedure is more suited to people with high levels of staining which cannot be removed with ultrasonic scaling etc.

The power bleaching technique involves a 30-35% hydrogen peroxide preparation in the form of a liquid, gel or powder being placed directly onto teeth [Thickett & Cobourne, 2009]. (Refer to figure 3 for a list of branded products currently available in the UK.) As the preparation is so highly caustic, tissue protection must be used, either rubber dam or a light cured resin shield. [Pretty et al, 2006] The activation of the hydrogen peroxide preparation depends on the system being used, but it could be either light activated (with a light cure or specially designed unit), chemically activated (in the mixing process) or a combination of the two.

Patients are often very satisfied with power bleaching results as they are visible immediately after treatment. It also requires minimal patient compliance. However, it is time consuming and need several visits to the dentist in order to ensure complete effectiveness of the treatment. The costs are also higher than those which can be purchased over the counter or take home systems. [Khin, 2007]

Clinician-assisted home systems

This technique involves the use of a bleach preparation being worn in a mouthguard, made specifically for the patient by the clinician, generally overnight for a specific amount of time depending on the instructions from the practitioner and manufacturer.

Alginate impressions of the patient’s teeth are taken by the clinician and normally sent away for a mouthguard to be made. The patient is then advised on how to apply the solution to the mouthguard, how to wear the guard and the exact instructions on how often to apply the treatment. On the whole, most systems appear to be based on wearing the guard daily for 2-4 hours in the day and overnight, for a couple of weeks. However, the length of time the guard should be worn for depends on the severity and type of staining, so relies on the judgement of the practitioner and their advice to the patient. For example, if the patient suffers from extreme tetracycline staining during tooth development, they may need to wear the guard for up to six months [Pretty et al, 2006].

This system has the advantage of being convenient for the patient as it can be applied when it is most suitable for them. They are also more economical than clinician supervised systems and don’t require frequent visits to the dentist, which can be time consuming and uncomfortable due to the use of rubber dam. However, this system involves high patient compliance. The patient needs to be motivated to persevere with the duration of the course advised. This can be difficult as results are not immediately visible, and the patients often give up. This reliance on the patient also means that there is an increased risk of misuse of the product [Khin, 2007]. Some patients with a strong gag reflex can find the tray uncomfortable and may not tolerate it well.

It has also been suggested in a review by Matis et al (2009) that home systems could also be recommended as a follow up to in-office bleaching “to ensure long term effectiveness” of the treatment.

Technique

Product Name

Home – Clinician assisted

Opalesence White

Nite White® ACP Bleaching Gel

iWhite Light Activated Teeth Whitening Kit

Aquafresh White TraysTM

Sapphire Professional Home Whitening System

Pola Zing Advanced Tooth Whitening System

Colgate Simply White and Visible White

Home – over the counter

Colgate Simply White

Crest night effects

Home- strips

Crest Whitestrips

Rembrandt Whitening Strips

ON-THE-GO Whitening Click-Pen

Pola Paint Advanced Tooth Whitening System

BriteSmile Whitening Pen

In-office

Zoom

BriteSmile

In office dual activated

Hi-Lite material

Figure 3. A table showing current products available on the market in the UK for tooth whitening; at- home and in-office systems. [Thickett & Cobourne, 2009]

Which system is the best?

The type of bleaching advised for patients depends greatly on a variety of factors. The nature of the staining is very important (intrinsic or extrinsic) as is the severity of staining. If the staining is mild, then less concentrated bleach could be advised, perhaps in a clinician supervised take home system. If the staining is more severe, then stronger bleach could be suggested, such as the 30-35% concentrations of hydrogen peroxide in in-office power bleaching.

The preference of the patient is also a factor to consider. Some, perhaps with time or economical constraints, may prefer to use a take-home system. Others who want a slightly brighter smile quickly could get an over the counter the counter system.

However, the efficacy and longevity of the systems are also another consideration as patients will not want to spend time and money on a procedure which doesn’t work effectively. There are a number of studies which have been carried out to determine which of the products currently on the market are the most effective. Efficacy of vital tooth whitening is usually determined by the number of shades the tooth has been lightened, for how long after the procedure this remains and any possible side effects, and depends on the bleaching agent and method used [Bizhang et al, 2009].

Tooth colour can be measured visually using a shade guide often provided by manufacturers with their products or by spectrophotometry which is a method to measure the wavelengths of visible light [Joiner et al, 2008] as the longer the wavelength, the darker the colour. Thus spectrophotometry can be used to measure shades of teeth more precisely and therefore the exact degree of whitening that the procedure has produced. Precision like this is used in clinical trials, whereas shade guides, which are much more approximate, can be used in clinics before and after whitening to show patients how much their teeth have been lightened.

In a study by Matis et al (2007), they evaluated eight different in-office systems and their longevity after six weeks. They found that all the systems had an effect and produced whiter teeth with a mean reversal of 65% after six weeks. However, the more successful products were found to have a longer contact time with teeth, and that the catalysing of hydrogen peroxide is more important than concentration. Therefore, it can be suggested that when using in-office bleaching, a light or chemically activated system is advised to enhance the effects of treatment.

In a second study by Matis et al (2009), they tested the efficacy of in-office tooth whitening when followed up by at- home tray whitening. They found that the effects of in office bleaching are more rapid, but has increased reversal (within two weeks) whereas the effects of at-home tray bleaching takes longer but have less chance of reversal. Therefore, when following up in-office bleaching with at-home tray whitening, they found that patients had better whitening after twelve weeks than when not followed up with tray whitening. They suggest that the two systems should be used in unison, to give rapid whitening and increase its effect. They also showed that a treatment plan of three fifteen minute treatments is better than one treatment of forty minutes, and produced fewer side effects.

A paper by Matis et al (2009) reviewed the effectiveness of various tooth whitening systems, including in-office, at-home tray and over the counter systems. They concluded that the most effective method was when the product was placed in trays and used overnight. Second most effective was when the product was used in trays for shorter periods of time during the day. They also found that “two weeks after completing the bleaching treatment, over-the-counter tooth whitening was as effective as in office tooth whitening”.

The effect of three different bleaching methods was investigated by Bizhang et al (2009) over three months; 10% carbamide peroxide gel used at home in a tray, 15% preparation of hydrogen peroxide for in-office use and 6% whitestrips. Significant differences were found between in-office and whitestrips and home trays and whitestrips but not between 10% carbamide peroxide for home use and 15% hydrogen peroxide for in-office use. The whitestrips provided least whitening of all and it was also noted that the subjects preferred the at-home tray method the best.

It is not just the delivery method which is an important factor, but also the agents used. The use of daytime bleach was investigated by Mokhlis et al (2000). They compared 20% carbamide peroxide against 7.5% hydrogen peroxide when used in trays at home and found that after two weeks, teeth whitened with carbamide peroxide were lighter than hydrogen peroxide. However, after twelve weeks there was no significant difference between the two in colour or sensitivity. Therefore, they concluded that both chemicals are equally suitable and effective for use in at-home trays.

The concentrations of the agents used, and if this has any major effect, is debatable. Although Matis et al (2007) suggested that the concentration is not as relevant as the contact time and the fact that the agents should be catalysed, it has since been suggested by Bizhang et al (2009) that concentration is still important. The effect of the concentrations of carbamide peroxide was analysed by Meireles et al (2009). The outcome after a one year investigation of 10% versus 16% carbamide peroxide used in at-home trays was that both concentrations produced the same median lighter shade than at baseline after one year, although there was more reversal on treatment with 16% carbamide peroxide. Therefore they suggest that concentration shows little difference in the long run.

This was also shown by Braun et al (2007), who tested the effects of 10% and 17% carbamide peroxide on enamel tooth surfaces. They concluded that both concentrations significantly whitened teeth with the only difference being that the higher concentration lightened teeth faster. Nevertheless, they did suggest that the lower concentrations should be used, to try to limit side effects such as hypersensitivity.

As shown, there are many trials and research carried out to evaluate tooth whitening products, and which are the ‘best’. There appears to be no outstanding system, as it depends on a variety of variables such as the needs of the patient, the teeth being bleached, the nature of the staining, the system being used, the concentration of the agent, the type of agent, the method of activation, and any adverse effects produced. However, there does seem to be more evidence to suggest that it is more advantageous to use at-home tray systems, as they are more convenient for the patient and have longer lasting effects than other systems.

Side effects

As with any procedure, there are always some adverse effects which can be produced, and may affect some patients. In a review by Khin (2007), she highlighted that the main side effect of vital tooth bleaching is tooth sensitivity, seen in between 55-75% of patients who undertake the treatment. One suggestion for post-whitening hypersensitivity is that the by-products of hydrogen peroxide/carbamide peroxide degradation (water and oxygen/urea) diffuse down dentinal tubules to the pulp. These by products then irritate the nerves in pulp and effectively cause reversible pulpits, accounting for the hypersensitivity [Hewlett, 2007].

The second suggestion is that the glycerine gel that bleaching agents are often carried by dehydrates the tooth. Glycerine exerts osmotic pressures on the dentine, causing fluid movement in the dentinal tubules and causing sensitivity, as suggested by Brännstöm [Hewlett, 2007]. Manufacturers now replace glycerine with water-soluble based solutions, to try and overcome this problem.

The pain experienced during a whitening procedure was investigated by Krause et al (2008) by asking patients to describe the pain when using either 17% or 10% carbamide peroxide. They found that there was a positive correlation between the concentration of the agent and the intensity of pain. They therefore suggested that lower concentrations should be used in practice, as they still provide the same results as higher concentrations, just not as quickly. A preliminary study by Chakaron et al (2009) investigated the use of 600 mg ibuprofen to minimise pain and sensitivity. They showed that it helped reduce pain during treatment, but not after. This is something which could be further investigated, to see if this could be used to help patients during the procedures.

The most common suggestion for avoiding bleaching hypersensitivity is to use potassium nitrate toothpaste twice a day for two weeks before carrying out the procedure [Hewlett, 2007] or in the tray for 10-30 minutes before the treatment [Khin, 2007] to desensitise the teeth. It is also suggested to keep the number of applications to a minimum.

Another side effect of tooth bleaching is gingival irritation, caused by prolonged contact of the gingiva with the gel. This can be from either in-office power bleaching or take-home trays. In in-office systems gingival protection is used to minimise the negative effect on the gingiva, however, it is more difficult to protect the gingiva in take-home tray systems as the patient is applying the product themselves. Therefore the clinician could minimise irritation by properly trimming the tray so that the gel will only come into contact with the hard surfaces of the tooth and not the gingiva.

In some patients it has been reported that they experienced some minor orthodontic movement when using take-home trays. This could have been due to the trays being made of rather rigid material, which put pressure on teeth to move, also causing sensitivity [Hewlett, 2007]. Trays are now made of more flexible materials to try to reduce pressure on teeth.

There can also be an adverse effect on restorations. If the marginal seal of the restoration is leaking there is an increased chance bleaching agents to penetrate deep into the dentine and pulp and therefore there is an increased risk of hypersensitivity. It has been recommended to replace failing restorations prior to bleaching [Hewlett, 2007].

There has been much debate on whether or not tooth bleaching has a negative effect on the composition of enamel and dentine. This is attributed to the free radicals produced during the dissociation of hydrogen peroxide being capable of disrupting the lipids and proteins (the organic component) in the tooth [Minoux & Serfaty, 2008]. A study by Markovic et al (2007) used laser scanning microscopy in vitro to investigate the micromorphology of the enamel surface after treatment with 10% or 16% carbamide peroxide. The results showed that the roughness of the enamel surface increased for both concentrations, indicating “loss of organic matrix after exposure to hydrogen peroxide”.

However, an in vitro by Delfino et al (2009), in which they tested 10% carbamide peroxide, 16% carbamide peroxide, 6.5% hydrogen peroxide and 6.5% hydrogen peroxide whitening strips showed that there was “no change to either the enamel surface microhardness or the enamel subsurface microhardness”. This was also illustrated by Mielczarek et al (2008), who compared the effects of 14% hydrogen peroxide whitestrips, 20% hydrogen peroxide (take-home tray system) and 38% hydrogen peroxide (in-office system) on enamel surfaces. They concluded that none of the systems demonstrated any “deleterious effects on surface roughness”.

These studies are only examples of many which have been carried out to determine the exact effect on tooth surfaces, and show that it is still unclear whether there is a detrimental effect.

Conclusion

Based on all the research that I have found, it appears that tooth whitening is a safe, inexpensive, and accessible method for patients to remove discolouration and gain a whiter, brighter smile. The type of staining, if any, which the patient presents with must be assessed first, as the types determine which system must be used, if at all as some staining cannot be removed with bleaching.

Though the exact nature of whitening is not fully understood, extensive studies have shown that the main side effect is hypersensitivity, which is quite common amongst patients undertaking the procedure but can vary considerably in pain intensity. The bleaching agents used, especially in in-office systems, are also rather caustic due to their concentration, and can burn the soft tissues in the mouth unless they are protected fist.

There are three main methods of tooth bleaching, each with their own advantages and disadvantages. Over the counter systems contain a minimal concentration of hydrogen peroxide, and therefore have little effect on the colour of teeth. In-office bleaching is much more effective, as contain 30-35% hydrogen peroxide, and show effects immediately.

Clinician-assisted take home trays are more convenient for the patient, as they can be used at their own convenience. It is also cheaper than in-office whitening, and studies have shown that the effects are just as good, if not better, than in-office whitening, and have the least reversal.

Therefore, in my opinion, take-home trays are the best system to use, as it is better tolerated by patients as it is more convenient and cheaper, and clinical studies have concluded that they are very effective at lightening teeth and have less chance of reversal.

Clinical Trials and studies are still being carried out, to try and determine the exact nature of tooth whitening, and therefore to maximise the effect. New procedures are also being tested, such as laser tooth whitening, which preliminary reports have shown to be very effective [Lin et al, 2008].

Word count

Excluding figures, contents page and references:

Health care is continually changing and searching for ways to improve the care that patients receive today. This is done in order to confirm they not only do they receive the highest quality of care, but also that it is the safest. For Evidence Based Practice (EBP), the Iowa model is a systematic method that explicates how organizations change practice in order to encourage quality care.  The Iowa model was originally a research utilization model.  Since then, it has been updated to embrace more prominence on EBP (Schmidt & Brown, 2019).  To promote quality care, it was renamed the Iowa model of evidence-based practice.   When using this model, there are many questions that need to be considered such as: “Is there a sufficient research base?”, “Is the topic priority for the organization?” and “Is change appropriate for adoption of practice?”.  When nurses ask and address these questions, many of the same issues are also addressed in the Stetler model which include, the need to gather research, identify achievable outcomes, applying the research to nursing practice, and evaluation of the application of research practice (Schmidt & Brown, 2019).

In the peer-reviewed article “Efforts of a Unit Practice Council to implement practice change utilizing alcohol impregnated port protectors in a burn ICU”, Martino et al. (2017) used the Iowa model during their evidence-based practice research.  Per Martino et al., studies have shown that central line associated bloodstream infections (CLABSI) are among the deadliest healthcare associated infections.  Their burn intensive care unit (BICU), had higher rates of CLABSI than the National Healthcare Safety Network CLABSI rate for burn centers that averaged 3.7 infections per 1,000-line days.  The BICU averaged 17.7 infections per 1,000-line days in 2008, 16.8 in 2009, and 8.3 in 2011 (Martino et al., 2017).  Due to this high infection rate, Marino et al. decided to investigate why they had higher CLABSIs.  It was determined that higher rate of CLABSIs was a priority for their unit. They wanted to figure out why they had such a high incidence and what was causing the higher rates compared to the National Healthcare Safety Network.

To address this issue, the BICU looked to the Army Nurse Corps’

Patient Caring Touch System of Care

(PCTS). PCTS was designed to decrease clinical variances by adopting best practice to improve the quality of care provided to their patients (Martino et al, 2017).  Nurses on the BICU implemented interventions such as: using alcohol impregnated port protectors, increased frequency of central line changes to decrease dwell time from seven to five days; mobile cart was stocked with CVC supplies that could be accessible to clinicians during placement; CHG dressing changes were performed daily (Martino et al., 2017).  Data was collected weekly for observational audits, members of the infection control committee conducted surveillance of the central line bundles along with identification and reporting of CLABSIs. Once all data was collected, it was discovered that implementing alcohol impregnated caps decreased the number of CLABSIs on their unit.  Martino et al. used the Iowa based model for their research. They identified the increased number of CLABSIs on the unit was a priority, there was sufficient research base, and it was appropriate for them to adopt the use of alcohol impregnated caps on their unit to decrease CLABSIs.

Beal and Smith (2016) used the IOWA model as well in their article “Inpatient Pressure Ulcer Prevalence in an Acute Care Hospital Using Evidenced-Based Practice”.  Their goal was to decrease the prevalence of hospital-acquired pressure ulcers (HAPU) at Maine General Medical Center in Augusta, Maine.  Per Beal and Smith (2016), the annual mean of pressure ulcers in 2005 was 7.8%.  The study was performed over a ten-year period.  Beal and Smith recognized the need and priority to decrease the incidences of HAPUs, there was enough research base, and the methods were appropriate to implement the practice into the facility.  They wanted to discover ways to decrease the occurrences of HAPUs in their hospital.  Maine General Medical Center set goals to increase the Braden score assessment from 85% to 100% upon admission, increase obedience with implementation of pressure ulcer prevention from 15% to 100% and increase documentation of interventions from 15% to 100% (Beal and Smith, 2016).  In order to assist in achieving their goals, in-services were provided on issues with compliance and what is considered best practice based on National Pressure Ulcer Advisory Panel (NPUAP).  A qualitative survey was also performed at the hospital.  It was discovered that there was poor communication, lack of time and knowledge and inadequate equipment on the unit which all assisted in the increase of HAPUs. After this was discovered, in-services, staff meeting on best practice, monitoring through chart reviews and adequate equipment was provided (Beal and Smith, 2016).  The operating room established a policy for pressure ulcer prevention (PUP) using memory foam and gel pads, skin assessments before and after the patient was in the prone position, and a four-person transfer process when moving a patient to prevent shearing.  Over the ten-year span, there was a decrease in HAPUs from 7.8% in 2005 to 1.2% and 1.4% for 2012-2014 (Beal and Smith, 2016).

In summary, the IOWA model is used to help explain how organizations change their way of practice to provide high quality patient care.  EBP is essential in nursing to implement best practices and to stay up to date about new medical protocols.  Both Marino et al., (2017) and Beal and Smith (2016) used the IOWA model during their studies.  Both identified the priority and need for the change. With the key component of having enough research and the appropriateness of the practice, evidence practice will be a success.

References

• Beal, M.E., & Smith, K. (2016). Inpatient pressure ulcer prevalence in an acute care hospital using evidence-based practice,
  
  13
  
  (2), 112-117. doi: 10.1111/wvn.12145
• Martino, A., Thompson, L., Mitchell, C., Trichel, R., Chappell, W., Miller, J., Allen, D., Salinas, E. (2017). Efforts of a unit practice council to implement practice change utilizing alcohol impregnated port protectors in a burn ICU,
  
  43,
  
  956-964. doi:10.1016/j.burns.2017.01.010
• Schmidt, N. A. & Brown, J. M. (Eds.). (2019).
  
  Evidence-based practice for nurses: Appraisal and application of research
  
  (4th ed.)
  
  .
  
  Burlington, MA: Jones & Bartlett

Breast cancer is the most common cancer in women in the UK and is currently the second leading cause of cancer deaths after lung cancer1. In 1988, the National Health Service Breast Screening Programme (NHSBSP) was introduced in the UK with an aim to detect small invasive cancers as well as pre-invasive cancers to reduce mortality from the disease

2. Despite being well received generally and have progressed over the years with positive outcomes2,

3, the NHSBSP is not without opposition and has its share of controversies

4.Of all the breast cancers diagnosed irrespective of mode of detection, 70-80% were of the invasive ductal type

5. These invasive cancers when detected at screening are however at an earlier developmental stage and more likely to be smaller and of lower grade6,7, correlating with better prognosis compared to symptomatic or interval cancers

8. Screen-detected cancers are also more likely to be treated with breast conserving surgery and sentinel node biopsy instead of total mastectomy and axillary node clearance9.

Case Report on screen-detected invasive ductal carcinoma

A 66 year old female patient underwent routine breast screening carried out in her local community. Her mammograms revealed a new 9mm spiculate mass (Figure 1) in the right upper outer quadrant of the breast, not present in her last set of screening films from 2007 (Figure 2). It looked highly suspicious of a carcinoma and was graded as R5 (malignant).

Figure 1. Invasive ductal carcinoma presented as 0.7mm spiculate mass on film mammograms. Taken from [21]

Magnified craniocaudal (CC) view of the mass.

Magnified mediolateral oblique (MLO) view of the mass. There are several long but fine spicules radiating from a central mass.

A

B

Figure 2. Normal screening film mammogram of the right breast taken in 2007.

A. CC view

B. MLO view

She was subsequently recalled to the hospital for further assessment, which consists of further imaging and needle biopsy. Clinical examination was insignificant, while a coned compression mammogram further confirmed the presence of the mass (Fig). Ultrasound scan showed a 9mm irregular hypoechoic area with posterior acoustic shadowing (Fig), giving a grade of U5 (malignant) and a core biopsy was obtained using ultrasound guidance.

The histopathology report of the core biopsy confirmed a finding of invasive ductal carcinoma (IDC), provisional grade 2 on microscopic examination. A supplementary report showed it to be oestrogen-receptor (ER) and progesterone-receptor (PR) positive, and HER-2 negative.

Later during the week, patient was given the diagnosis of IDC and agreed to breast conserving surgery that will be done with the help of ultrasound localisation. A sentinel node biopsy will also be carried out. After the surgery, the excised tissues and sentinel lymph nodes will be analysed in the laboratory, and the histopathology results will indicate the prognosis and course of future treatments for the patient.

This plan of action was agreed upon during a multidisciplinary team meeting and the patient will be reviewed again in the meeting after the surgery.

Discussion

Epidemiology of breast cancer

Breast cancer is an important public health issue in the UK to date. In 2006, the incidence of breast cancer in the UK was approximately 46,000, representing a two-fold increase over a 30 year period1. In this similar time period, a fall in breast cancer mortality rates was seen10 (Figure 1). This can be attributed to advancements in the management and treatment of breast cancers and early detection of cancers from screening. The opposing trend in incidence on the other hand, can be accounted by a change in environment and lifestyle as well as an increase in cancer detection after the introduction of the breast screening10.

Figure 1. Age standardised (European) incidence and mortality rates of female breast cancers in UK from 1975 to 2005. Taken from [10]

Breast screening programme in the UK

The National Health Service Breast Screening Programme (NHSBSP) was introduced in the UK in 1988 in response to ‘The Forrest report’ which concluded that women aged 50 and over can lead a longer life as a result of mammographic screening11. The NHSBSP initially screened women between the age of 50 and 64 once every 3 years using single view mammography but has made changes with new evidence from randomised controlled studies12,13.

Currently, the NHSBSP screens women from 47 to 73 years of age using double view mammography and this has improved the detection rates of small cancers12,14. It has been estimated that since the programme began, over 100,000 breast cancers have been detected15.

Mortality from breast cancer has been shown to decrease by 25% in the UK13 and it has been reported that NHSBSP saves approximately 1400 lives annually2. These figures demonstrate an apparent benefit of a breast screening programme which is vital as screening essentially diagnose otherwise healthy women with cancer. Without a clear benefit, in light of evidence that screening can do harm, it would be difficult to justify its use on such a large scale.

Overview of the breast screening process

Figure 2. The breast screening process in the UK. Taken from [10].

All women between the age of 47 and 73 in the UK who are registered with a general practitioner (GP) are eligible for breast screening under the NHSBSP. The process of screening is summarised in Figure 2. There has been further expansion of the screening age group after year 2008 from women aged 50 to 70 years to include women aged 47 years and over up until 73 years of age22. Women over 73 years of age can continue to be screened provided they request it from their GPs.

The GP is responsible for identifying and inviting those who are eligible for screening. The basic screen normally takes place in the community, for example on a mobile screening van, in order to improve the uptake of screening by the population. A minimum target of 70% uptake from those invited is necessary in order for NHSBSP to be cost-effective14. In the UK about 75% of those invited attended for screening2.

The basic screen involves x-ray mammography taken in two views which are the mediolateral oblique and craniocaudal view. Each set of mammogram is then interpreted by two trained readers, independant of each other, a process supported after results of double reading in screening17. When there are any discrepancies with the readings, they are further reviewed during the process of consensus and arbitration. A large majority of women screened will have normal mammograms and will be sent a letter within 2 weeks regarding their results. They will then continue to remain in the normal screening programme.

Around 3 to 10% of women will be recalled for assessment either due to findings on mammograms or technical recall10. Findings on mammograms which warrant further assessment include appearance of masses, microcalcifications, architectural distortion and asymmetric densities2. It is estimated that around 1 in 10 women recalled will have the diagnosis of breast cancer14. Recall rates for ‘prevalent round’ screens are higher compared to ‘incident round’ screens while digital mammography have reduced the number of technical recalls compared to film mammography.

Women who have then been recalled for further assessment will undergo additional imaging using an ultrasound scan. Further mammographic imaging, clinical examination and needle biopsy may be carried out as well. This stage in assessment may incorporate a multidisciplinary approach, involving radiologist, radiographers, pathologists, as well as breast surgeons. Such a structure can ensure that women are thoroughly assessed, and those with normal findings can be reassured immediately. Patients who have undergone needle biopsy however, will have to be brought back to the clinic in about a week’s time for their results. Less than 1% of these women will require surgical referral and the rest will return to the normal screening programme10.

Advantages and disadvantages of mammography

Mammography has undergone many randomised trials for its use in breast screening and is still currently the gold standard method for screening. It has been shown that breast cancers detected from mammography screening are more likely to be smaller, and of lower grade which have yet to infiltrate into the surrounding lymph nodes16. This stage shift of screen-detected cancer is largely responsible for the improved survival, as survival is dependant on size, grade and lymph node status of the cancer according to the Nottingham Prognosis Index (NPI).

Mammography as a screening modality is not perfect as it has its disadvantages. The recall of women following breast screening is associated with a higher degree of anxiety and emotional distress20. Even though women who are diagnosed with breast cancer through screening or symptomatically experience similar levels of anxiety, women who experience false positive recalls (1 in 8 regularly screened over a period of 10 years) 2 may suffer from anxiety that may persist for some months. After 3 months however, their levels of anxiety are no different from control groups2.

Another issue for concern is the radiation risk of mammography. X-rays from mammography will cause one breast cancer death for every 14000 women screened over a period of 10 years2. The risks posed to the 50 to 70 age group however, is small when taken into account the benefit of reduced mortality. It is estimated that 40 breast cancer deaths is prevented at the expense of 1 breast cancer death from radiation exposure18.

There are also more cases of breast cancer diagnosed in women who attend regular mammographic screening. These cancers tend to be small or are pre-invasive in nature – ductal carcinoma in situ (DCIS). The detection of DCIS has increased from 3% to 25% after the start of the screening programme14, and has contributed to a decrease in mastectomies2. Evidence have shown that DCIS may be a precursor for invasive cancer and before the launching of the programme, 1 in 3 women with untreated DCIS, developed invasive cancer 10-20 years later2.

With the rise in cases of breast cancer due to screening there is an issue of overdiagnosing and subsequently overtreating for breast cancer, as 1 in 8 women with screen-detected breast cancer would have succumbed to another illness before their breast cancer have any clinical impact2. These breast cancers whose diagnosis has no impact on overall survival are said to have lead time bias14, with them ending up living with the disease for a longer period of time. Another issue is with length-time bias, whereby cancers that would have otherwise been clinically silent in the woman’s life time due to the low grade nature of the cancer is detected, leading to unnecessary treatment14.

There is currently no way of differentiating between cancers that will prove fatal if left untreated from those that have no clinical consequences. Therefore all cancers diagnosed will be managed with surgical interventions, systemic treatments or both.

Other screening methods

Mammography is not the imaging of choice in women under the age of 40. Young women tend to have more glandular breast tissues which produce mammograms that are more difficult to interpret. There is also the more concerning issue that radiation from annual mammography in women under 40 years may do more harm than good18. As a result, there is an increasing favour towards the use of magnetic resonance imaging (MRI).

Presently, contrast enhanced MRI is sometimes used alongside mammography in diagnosing the extent of disease. MRI is also currently used to monitor patient’s response to systemic treatments such as chemotherapy and is of some value in the screening of high risk patients. Studies have also shown that MRI has greater sensitivity in detecting both invasive and in situ carcinoma compared to mammography. However these are small studies and MRI has its fallbacks in terms of costs and high false-positive rates19.

NHSBSP screen patients with low risk of breast cancer, and any patients with increased risk are offered screening outside of the programme. These women are offered yearly screening as opposed to the triennial screening offered by the NHSBSP. The starting age of screening will largely depend on the calculated risk for each individual woman. High risk women are offered screening at around the age of 30 to 35, while women with moderate risk begin screening at 40 years of age20. There are risks involved in screening of younger patients and they must be well informed of the potential harms they may incur as a consequence.

Screen-detected cancers

Overview

Recent controversies

A narrative review4 was recently published in the Journal of the Royal Society of Medicine which critiques the NHSBSP 2008 annual review15. The review challenged the conclusion of the NHSBSP annual review and criticised it for emphasizing too much on the benefits of breast screening and overlooking its harms.

This narrative raised controversial issues regarding the benefits and harms of the screening programme despite convincing evidence of a reduction in mortality with breast screening3. Nevertheless, with favourable support for the latter2,3, it is difficult to ascertain whether there is more harm than good for breast screening, as speculated by the review.

One of the authors of this review also published a Cochrane review10 with a conclusion that breast screening is likely to reduce mortality but whether the benefits outweighed the potential harms of screening is still questionable.

Challenges and controversies raised in such publications is a crucial process as it is through debate and discussions that ways of improving and developing the breast screening programme will be proposed by experts in order to resolve the conflicts.

Conclusion

With the benefits of early detection of potentially fatal disease, the NHSBSP will inevitably result in the overdiagnosis and overtreatment for breast cancer in some women. As it is not yet possible to determine whether cancer detected through screening will be fatal or not, it seems unethical to leave cancers untreated due to potential for harm. This issue will remain controversial until new evidence and research arise, but until then, it is important to keep women well informed, so they can make the choice that is right for them.