Oral hygiene is the care of the mouth, including the gums, teeth or dentures, tongue, inner cheeks and lips; and it is an integral and essential component of nursing care (Smith et al, 2017; Coker et al, 2017). Effective oral care cleanses and protects the mouth by removing debris, preventing the build-up of plaque, and minimising the risk of further complications (Costello and Coyne, 2008). Ineffective oral hygiene causes a build-up of plaque, leading to halitosis, decay and pain (Fitzpatrick, 2000). When the mouth is healthy, a symbiotic relationship exists between the mouth surfaces and oral microbes, which acts as a barrier to other harmful organisms. This barrier takes the form of a thin moist layer over the surface of the teeth, the tongue and gums, known as a biofilm. This can either protect the environment or, if the biofilm is allowed to build up, can create plaque and produce an environment suitable for the development of infections (Marsh, 2018).
When the flow and composition of saliva are normal, the teeth and soft tissue are protected, the mouth remains moist, food is lubricated during eating and micro-organisms are removed (Dennesen et al, 2003). During eating, saliva production increases due to stimulation (Lewis and Lamey, 2019). A reduction in, or lack of, oral intake prevents mastication and leads to a decrease in enzyme and saliva production, which prevents the removal of debris, resulting in the build-up of plaque (Kostler et al, 2001; Squier and Kremer, 2001). Saliva flow is greatly reduced at night due to a lack of stimulation and also reduces with age (Public Health England (PHE), 2017; Rogus-Pulia et al, 2018; Lewis and Lamey, 2019). Therefore saliva plays an important role in maintaining oral health and, when reduced, oral health is compromised.
The author wished to explore the literature that already exists in this area and the effectiveness of available products. The major themes to explore included the use of products for xerostomia, dysphagia, mucositis and for people wearing dentures.
The author also reviewed products used in practice in her own hospital.
Aim
The aim of this review was to:
Methods
The search engines used for this literature review included CINAHL, PubMed, Cochrane Database and Google Scholar. The search terms used were ‘oral hygiene,’ ‘oral care’, ‘mouth care’, ‘oral health’, ‘products’, ‘nursing’, ‘nurse’, ‘knowledge’, ‘attitudes’, ‘experience’, ‘practice’, ‘evidence based’, and ‘education’. A combination of these search terms with ‘and/or’ were explored. The inclusion criteria were articles in the English language published between 2007 and 2019, although any significant studies outside this time frame thought to be relevant to this project were also explored. Non-English language articles were excluded.
Search outcome
Some 280 citations were found and abstracts were reviewed for relevance. As a result, 113 full articles were reviewed and 45 were included in the final study. These included systematic reviews, meta-analyses, randomised controlled trials, Cochrane reviews and surveys.
Quality appraisal
All articles were discussed with another researcher and some were further assessed by a dentist. Articles were entered into a table and compared and contrasted for themes, with reference lists checked for any additional articles.
Data abstraction/synthesis
All articles were compared and contrasted in a table format and some discounted due to the quality of the evidence (Cochrane EPOC Team, 2017). Studies were examined for their similarities and differences. The PRISMA diagram shows the study selection process (Figure 1) (Moher et al, 2015). A number of oral-care problems were identified from the review. Some articles reviewed the use of xerostomia products and were funded by the manufacturing company, which introduced the possibility of bias. However, for a discussion of available products, these were still included in the review.
Results
There is a lack of consensus on oral-care products and selection is rarely evidence based but made according to nurse preference, tradition, cost, availability or prescription of products (Cohn and Fulton, 2006). Toothbrushes and paste are the most commonly used oral-care products (Cohn and Fulton, 2006; Prendergast et al, 2013).
Foam swabs
One study surveying nurses in neuro-rehabilitation determined that foam swabs were used by 87% of nurses, although toothbrushes were also used (Odgaard and Kothari, 2019). The concern is that foam swabs are used instead of toothbrushes even though swabs do not replace the need for toothbrushing. Dyck et al (2012) determined that mouth swabs were inferior to cleaning the mouth compared with toothbrushes, although this has been debated. Marino et al (2016) demonstrated no difference between toothbrushes and mouth swabs for the reduction of plaque. Dale et al (2016) carried out an ethnographic study and reported that the texture of these swabs was not popular with patients and made oral care more difficult. The UK Medicines and Healthcare products Regulatory Agency (MHRA) (2012) reported the death of an elderly person after a carer used a foam swab that became detached and was swallowed. Therefore, to reduce the risk of choking, a soft-bristled brush should be used instead of mouth swabs. Foam swabs with lemon and glycerin can cause complications by lowering the pH of the mouth, leading to teeth decalcification and xerostomia, subsequently causing pain, irritation, and decay (Berry et al, 2007). Therefore the use of foam swabs should be avoided.
Toothbrushes
Brushing with a toothbrush and toothpaste prevents plaque build-up, periodontitis and gingivitis (Chan and Hui-Ling Ng, 2012; New Zealand Dental Association, 2010; Prendergast et al, 2012; Prendergast et al, 2013). Yaacob et al (2014) carried out a systematic review of articles in the Cochrane Database, which demonstrated that the use of electric toothbrushes produced moderately improved results for preventing plaque and gingivitis when compared with manual brushing, with a recommendation to brush teeth for 2 minutes. Similar results were reported by a randomised controlled trial of nursing home residents (Fjeld, et al, 2014). However, electric toothbrushes are seldom available in hospital. By brushing at least twice a day, the risk of pneumonia and resulting mortality is reduced (New Zealand Dental Association, 2010; PHE, 2017). Guidelines and educational tools recommend twice-daily brushing for 2 minutes (Prendergast et al, 2013; Smith et al, 2017). However, patients with dysphagia, which is a pertinent issue among neuroscience patients, may require more frequent tooth brushing due to food pocketing (Cohn and Fulton, 2006; New Zealand Dental Association, 2010; Prendergast et al, 2013). Gentle brushing with a soft toothbrush is essential to prevent oral mucosal injury (PHE, 2017). Toothbrushes should be stored upright and not in solution and should be changed at least monthly and more frequently if the patient is immunocompromised (Quinn et al, 2019).
Toothpaste
Fluoride is an important component of toothpaste, preventing tooth decay by protecting tooth enamel. PHE (2017) recommended a toothpaste fluoride strength of at least 1350 parts per million (ppm) for twice-daily brushing. For dependent or older patients, a strength of 5000 ppm is suggested (New Zealand Dental Association, 2010). A typical toothpaste such as Colgate Total has a fluoride concentration of 1450 ppm and a pH 6.8–7.2. Foaming toothpaste contains sodium lauryl sulphate, a detergent that can cause xerostomia (Moore et al, 2008; Prendergast et al, 2012). Therefore a non-foaming toothpaste, such as Oral 7, may be beneficial for dry mouth. This has a fluoride concentration of 1000 ppm and a pH 5.7–6.3. Individuals should not rinse after tooth brushing, but spit out any excess paste and leave the rest to maintain the fluoride content in the mouth (PHE, 2017).
Denture care
Ill-fitting dentures cause irritation, which disrupts the integrity of the mucosa (Quinn et al, 2019). If ineffective denture care is provided, denture plaque and inflammation can result. Denture stomatitis, which is inflammation of the mucosa below the denture, can also occur (Gendreau and Loewy, 2011; Coker et al, 2017). Dentures should not be worn overnight (Bartlett et al, 2018). According to Iinuma et al (2015), if dentures are worn overnight, the risk of pneumonia increases significantly.
To prevent degradation of the surface of dentures, a denture toothpaste or soap should be used because other t oothpastes may be too abrasive (New Zealand Dental Association, 2010; Bartlett et al, 2018; Quinn et al, 2019). For example, Colgate Total has a relative dentin abrasivity (RDA) of 70. The lower the RDA, the less abrasive it is. Oral 7 toothpaste has an RDA of 55, so could be used for dentures. Dentures should be removed from the mouth and cleaned at least twice daily, and removed at night time to prevent pneumonia, and pressure damage.
A denture care observational study was carried out on an acute, older-persons' hospital ward (n=25) to follow the practice of nurses carrying out oral and denture care (Coker et al, 2017). There was a variety of denture practices and inconsistencies between the staff. Duyck et al (2013) carried out a randomised trial (n=51) on denture storage overnight. They examined whether there was a difference in the rate of plaque formation and bacterial growth when using water storage, dry storage or denture-cleaning tablets dissolved in water. They determined that denture-cleaning with effervescent tablets and water significantly reduced the rates of bacterial growth by up to 13.8% compared with dry storage or water storage. Denture-cleaning tablets remove plaque and disinfect the dentures (Bartlett et al, 2018). Therefore dentures should be stored in a sealed container overnight with water and a denture-cleaning tablet.
Suction
Oral suction is important for mouth care in patients with impaired swallow, to prevent aspiration. Suction may also be required for patients who have to lie flat, such as those with spinal injuries. Yakiwchuk et al (2013) carried out a randomised controlled trial (n=22) of suction toothbrushes for patients with dysphasia in a long-term care facility. They explored whether oral suction toothbrushes prevented pneumonia, but determined that there was no difference between using a manual toothbrush or a suction toothbrush. Avanos produces a suction toothbrush designed for patients with dysphagia. Suction is associated with xerostomia, which should be considered, although patients with dysphagia or reduced consciousness may require suction to prevent aspiration pneumonia.
Saliva substitutes, stimulants and moisturising gels
Saliva stimulants and substitutes exist to prevent or reduce the incidence of xerostomia. Saliva stimulants have a low pH. The regulation of oral pH is fundamental to maintaining a healthy environment. Saliva maintains the oral pH between 6.2 and 7.6; however, if the amount of saliva reduces or acidic foods or drinks and sugars are introduced, this compromises the neutrality of the mouth and increases the risk of bacterial growth (Baliga et al, 2013). A Cochrane review analysed the effectiveness of saliva substitutes and stimulants in 36 randomised controlled trials (Furness et al, 2011). There was no strong evidence that either stimulants or substitutes reduced xerostomia. However, patients reported that their symptom of xerostomia improved with the use of these products. Some saliva substitutes may coat the tongue to retain moisture, whereas saliva stimulants increase the production of saliva (Furness et al, 2011).
Products to treat xerostomia include toothpastes, mouthwash and moisturising gels. Biotène, BioXtra and Oral 7 products were investigated for their efficacy in relieving xerostomia. The validity of studies comparing products is questionable due to the small sample sizes and sponsorship by the manufacturers (Shahdad et al, 2005; Aliko et al, 2012; Epstein et al, 1999). The toothpastes in the above ranges all contained fluoride and the LP3 protein enzyme system (comprising lactoperoxidase, lysozyme, and lactoferrin); Biotène did not include calcium. None of the three products contained alcohol or sodium lauryl sulphate, which contribute to xerostomia. Oral 7 contains aloe vera and calcium, and is designed to prevent mucositis after radiotherapy (Worthington et al, 2010; Dost and Farah, 2013). A small study concluded that mouth moisturising gel reduced the number of microbes significantly (Tajima et al, 2017). Rogus-Pulia et al (2018) carried out a study on otherwise healthy individuals, who reported an increased effort in swallowing as a result of a perceived dry mouth (P=<0.001); this reduced after an application of a saliva substitute.
A local review of a new product range completed by the author found that Oral 7 toothpaste used in combination with Oral 7 gel for patients with dry mouth, or when unable to eat and drink, was perceived as beneficial to patients and prevented deterioration of the mouth. The Oral 7 gel, which has a pH 6.4, acts as saliva and neutralises the oral environment, preventing the build-up of a coated tongue as occurs with some saliva substitutes. Some patients prefer to use a gum for xerostomia, although this may not be possible for patients with reduced cognition or poor swallow (Bachok et al, 2018).
A randomised, double blinded, cross-over study compared GUM Hydral Mouthwash and Gel and Biotène Oralbalance Mouthwash and Gel. Both significantly reduced the signs of xerostomia (P<0.05), including taste loss, pain and dryness (Barbe et al, 2018). Biotène reduced halitosis and plaque scores. The authors concluded that these products improve xerostomia but cannot completely replace saliva secretion.
Tongue scraping
The tongue is a large surface for the collection of food, saliva, dead epithelial cells and micro-organisms. Tongue scraping reduces bacterial load, preventing halitosis and maintains oral hygiene (Bordas et al, 2008). This may also be required to remove the coating produced by some saliva substitutes. Bordas et al (2008) carried out a blinded cross-over study (n=19) and discovered that tongue scraping with a toothbrush in combination with tooth brushing on a regular basis significantly reduced the presence of some bacterial categories on the tongue. This study showed statistically significant results for Gram-negative anaerobes (P=0.033), and Streptococcus salivarius (P=0.013) when combining tooth brushing with tongue cleaning. A tongue scraper is thought to cause more trauma than using a toothbrush to clean the tongue (Outhouse et al, 2006). However, if an oral gel such as Oral 7 is used, this may prevent the need for tongue scraping due to its antimicrobial and moisturising properties (Bachok et al, 2018). A thickly coated tongue would need gentle brushing rather than scraping with a soft toothbrush and then application of Oral 7 gel.
Mouthwash
Chlorhexidine mouthwash or gel is commonly used in practice but this has a drying effect on oral mucosa and can cause mouth ulcers as a result (Eilers, 2004; Shi et al, 2013). Staining of the teeth and a change in taste has been reported in the use of chlorhexidine mouthwash (Eslami et al, 2015). Chlorhexidine gel was found to reduce the risk of aspiration pneumonia in some patients (Smith et al, 2017). Sodium bicarbonate used as a mouth rinse was compared with chlorhexidine mouthwash in a randomised trial and no difference in results was seen between the two products (Berry, 2013). Sodium bicarbonate loosens debris and removes mucus (Berry, 2013).
Oral mucositis is a condition that often occurs in patients undergoing chemotherapy and radiotherapy, and is the inflammation of the oral mucosa (Al-Ansari et al, 2015). Bachok et al (2018) carried out a trial comparing salt soda mouthwash with Oral 7 mouthwash and determined that Oral 7 mouthwash, with a pH 5.4–5.6, was superior to the salt-based solution for patients with mucositis. Oral 7 mouthwash includes natural enzymes that are similar to those in human saliva and it therefore boosts the protective function of saliva. It supplements insufficient saliva in patients with mucositis without burning the mouth because it contains no alcohol (Bachok et al, 2018).
Mouthwash should be avoided immediately after brushing because it will wash away the concentrated fluoride in the toothpaste (PHE, 2017). Furthermore, complications can occur when using a chlorhexidine mouthwash for a sustained period of time, such as staining of the teeth and xerostomia, but it is effective in reducing rates of biofilm and gingivitis (PHE, 2017; Takenaka et al, 2019). The quality of evidence to support the use of fluoride mouthwash remains low (Takenaka et al, 2019).
Oral candidiasis
Oral candidiasis, or thrush, is due to the presence of Candida, most commonly Candida albicans, a fungus that can develop in the oral mucosa (Akpan and Morgan, 2002; Singh et al, 2014). This condition can be more prevalent in patients with an altered production of saliva, a high carbohydrate diet, those taking some drugs (such as longer-term use of antibiotics and corticosteroids), in immunocompromised patients, hospitalised patients and in the presence of xerostomia (Kragelund et al, 2016). Denture wearers are also at increased risk of this condition, known in this case as denture stomatitis (Kragelund et al, 2016). Lyu et al (2016) conducted a systematic review and meta-analysis and recommended nystatin as the first-line treatment for this condition.
Discussion
Diagnosing halitosis and xerostomia is subjective and nurses may disagree about the presence or severity of these conditions, and therefore treatments may vary. A variety of products used for oral care have been explored with varying degrees of effectiveness, and there is a lack of consensus. Essentially, the minimum standard of care should consist of teeth cleaning with a toothbrush and fluoride toothpaste twice a day, followed by spitting without rinsing. The care of dentures should be considered, with denture toothpaste applied twice daily and the removal of dentures overnight. Dentures should be soaked in water containing a denture-cleaning tablet overnight in a sealed container. The use of a variety of products have been discussed for relieving the symptoms of xerostomia, but the research was inconclusive. However, reviews of Oral 7 products, including a mouth gel and toothpaste for xerostomia, have found them to be beneficial.
In the author's hospital, Oral 7 mouthwash was found to be beneficial for cancer patients with mucositis, providing them with some relief, and was recommended by the dental department. A local review of Oral 7 products by the author found that they were beneficial for patients with mucositis, xerostomia and dysphagia. Table 1 provides a summary of recommendations for the author's hospital following this literature review and the author's product review. Products that should be removed from practice include foam swabs and the routine use of alcohol-containing mouthwash. Oral candidiasis should be recognised and treated early with nystatin.
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Conclusion
This literature review has explored the benefits of oral-care products for the hospitalised patient. A variety of products used for oral care have been researched, finding varying degrees of effectiveness. An overprovision of products has led to confusion as to when to use them. The minimum standard of care should consist of teeth cleaning with a toothbrush and fluoride toothpaste twice a day. The care of dentures should be considered, with denture toothpaste, denture-cleaning tablets and a sealed denture container provided for these patients. The literature reported on a variety of products used to relieve the symptom of xerostomia and mucositis. Further research into these products is required. A comprehensive oral-care guideline is needed to encourage the use of effective products, with simplicity the key to the implementation of effective oral care.