All authors drafted the protocol, registered it with the National Institute for Health Research PROSPERO (http://www.crd.york.ac.uk/PROSPERO, ID number: CRD42024497782), and reported it according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) checklist (Supplementary Table S1).

We developed a protocol to answer the following PICO question: “What are the perceptions of health care professionals regarding oral health care for dependent nursing home residents?.” The respective statements were as follows:

Cross-sectional observational studies were eligible for inclusion if they addressed the perceptions, difficulties, activities performed, and knowledge of health care professionals providing oral health care to dependent adults in long-term care facilities. Exclusion criteria were as follows: 1. duplicate studies; 2. abstracts, commentaries, reviews, letters to the editor, consensus, opinions, case studies, and case series; 3. unpublished information; 4. absence of the data being studied; 5. data obtained through a non-structured interview with non-comparable results; 6. population being family members as informal caregivers; and 7. articles written in languages other than English, Spanish, Portuguese, or French. There were no restrictions on the year of publication.

We searched PubMed through PubMed/MEDLINE, Web of Science, and LILACS for all relevant articles published until December 2023. The following search terms were used: (1) (care home OR nursing home OR residential OR caregiver* OR care facilities); (2) (elder* OR senior* OR old OR aged OR geriatric); (3) (oral health OR oral care OR oral knowledge OR health care). Two independent reviewers (J.P.L. and I.R.) performed the search and included studies. Two independent reviewers independently assessed the titles and/or abstracts of the retrieved studies in duplicate (J.P.L. and I.R.), and disagreements were resolved by discussion with a third author (J.C.). For measurement reproducibility, inter-examiner reliability following full-text assessment was calculated using the kappa statistic.

The methodological quality of the eligible studies was assessed using the Newcastle-Ottawa Scale (NOS) (21), which was adapted for cross-sectional studies (Appendix 1). This adapted version of NOS evaluates three major domains for potential sources of bias: (1) selection bias (methods of participant selection), (2) comparability bias (methods of controlling for confounding variables), and (3) outcome bias (methods of assessing outcomes). Each of the seven items on the scale is assigned a star, with a maximum of one star per item. In this review, both selection bias and outcome bias were of particular concern due to the reliance on self-reported data, which can introduce a range of biases, such as recall bias or social desirability bias. Therefore, we assessed whether studies adequately controlled for such biases by using validated tools, objective measures, or triangulation of data sources where possible. The risk of bias assessment was conducted by two researchers (J.P.L. and I.R.), with any disagreements resolved by consulting a third researcher (J.C.). If a study was deemed to have a high risk of bias in any domain, we noted this in the quality assessment summary and took it into account when interpreting the findings.

Data extraction was performed independently by two reviewers (J.P.L. and I.R.), with discrepancies resolved through discussion with a third reviewer (J.C.). The following information was extracted from each eligible study: first author’s name, year of publication, country and location of sampling, sample size (male/female), mean age and mean years of experience, oral health perceptions of health care professionals, type of assessment, and study funding. For nurse perceptions, some specific information was collected from the studies for comparison: knowledge of dental terms/oral health; previous training to provide oral health care, type of training and perceived need for additional training; oral health care activities performed and availability of supplies to perform such care; access to oral health care by an oral health professional, perceived barriers/difficulties; and importance placed on oral health/relationship of oral health to systemic health.

We recognize that this review relied on self-reported data (e.g., surveys or interviews) to assess health care professionals’ perceptions and practices. While self-reported data are commonly used in research of this nature, they introduce a potential source of bias, such as social desirability bias, where respondents may report behaviors or attitudes, they believe are more socially acceptable or expected. Additionally, recall bias may influence the accuracy of self-reports, particularly when participants are asked to reflect on past experiences or behaviors. These limitations were considered when assessing the overall quality of the studies, and we critically discuss their potential impact on the findings in the subsequent sections.

For data analysis, standard spreadsheet software (Microsoft Excel for Mac, version 16.50. Microsoft, Redmond, WA, United States) was used to extract data. Frequencies and percentages were used to describe categorical variables, while continuous variables were reported as mean ± standard deviation (SD) and range.

The online search strategy identified 2,091 potentially relevant publications. After removing duplicates, 1,455 articles were assessed for eligibility criteria and 1,359 were excluded after title and/or abstract review. Of the 96 articles assessed for eligibility through full paper review, one could not be retrieved and 60 were excluded, with reasons for exclusion detailed in Supplementary Table S1. As a result, a final number of 35 observational studies were included for qualitative synthesis. The PRISMA plot is shown in Figure 1. The inter-observer reliability of the full-text screening was considered substantial (kappa score = 0.614, 95% CI: 0.471–0.757) (22).

A total of 6,179 participants, 4,219 women, and 554 men (1,406 did not report gender), from all 35 included studies were included in this systematic review (Table 1). The calculated percentage of 88.4% of female participants corroborates the literature, where most caregivers were female. The sample included personnel directly involved in providing oral health care to residents of health facilities: mostly nurses, assistant nurses, qualified aides, non-qualified aides, and some articles categorized them only as caregivers or careers (23–37). Others included diverse populations such as occupational therapists, speech therapists, social workers, physiotherapists, nursing students, dental nurses, and dental hygienists (15, 16, 38).

Of the 35 articles included, 9 articles (about 17%) were published before 2010 (16, 17, 24, 25, 39, 40), with the oldest article published in 1999. All the remaining articles were published after 2010, and about 43% of them were published after 2015. The latest article was published in 2023.

Most of the studies were conducted in care facilities for the older adult, with the exception of one study developed in a hospital setting (41).

Several issues were considered in the case definition setting. Some studies addressed more than one issue: 29 studies searched barriers or difficulties felt when performing oral health care activities (14–18, 23–25, 28–33, 35–49), 13 studies assessed the perceived importance of oral health care (28, 30, 31, 34, 35, 41, 42, 50, 14–18), 19 accessed oral health knowledge (14, 18, 23, 28, 30–37, 40, 42, 46–49, 51), 20 studies emphasized previous training received (14–16, 18, 23, 26–28, 32, 35, 39–43, 46–48, 51, 52), and 24 the perceived need for training (14–18, 23, 25, 27, 30, 32–38, 40, 42, 45–50). The other 14 studies mentioned the access to oral health care by an oral health professional (14–18, 24, 30, 31, 35–37, 39, 40, 42, 48), 22 studies explored the oral health care activities performed (14, 18, 23, 24, 26, 29–37, 40, 41, 43, 46–49, 52), and 7 studies evaluate if supplies to perform such oral health care activities were available (18, 25, 29, 30, 32, 33, 46).

The methods used to collect data on oral health care provided by caregivers varied between studies and some applied more than one. Questionnaires were used in 24 studies (14–16, 18, 23, 25, 26, 28, 29, 31, 32, 36–39, 41, 42, 44, 45, 47–49, 51), semi-structured interviews in 8 studies (17, 24, 27, 30, 33–35, 40), and a more systematic data collection approach using the NDCBS in 5 studies (26, 27, 46, 50, 52).

Furthermore, studies were conducted in 17 countries worldwide: Turkey (23), Brazil (24, 29–31, 33, 34, 51), France (42), Switzerland (39, 41), Taiwan (43), USA (25, 37, 45, 52, 53), Sweden (40, 44, 47, 50), Chile (26, 27), Malaysia (14, 28), Finland (15), Australia (17, 35, 36, 48), Iceland (46), Serbia (32), Japan (16), Netherlands (18), Norway (49) and Belgium (38). Of note, no studies were performed in Africa.

The methodological quality of the studies varied significantly, with most studies falling into the fair (31.4%, n = 11) or high (28.6%, n = 10) quality categories, and 7 studies rated as low quality (Table 2). None of the included studies described and calculated the non-response rate (item 3). Studies mostly failed to identify confounding factors and to perform a subgroup or multivariable analysis taking them into account (51.4%, n = 18) (item 5) and to use a validated screening/measurement tool (88.6%, n = 31) (item 4). This presents a concern regarding the reliability and generalizability of the findings.

The heterogeneity of the studies was also evident, as different data collection methods were used, including questionnaires (24 studies), semi-structured interviews (8 studies), and the Nursing Dental Coping Belief Scale (NDCBS) (5 studies). This methodological diversity complicates direct comparisons between studies and highlights the potential for bias introduced by the lack of standardization in measurement tools. Furthermore, the study populations varied widely, including different categories of health care professionals (e.g., nurses, aides, dental professionals) across various countries, settings (nursing homes vs. hospitals), and types of training (formal vs. informal). This variation in study design and execution calls for caution in interpreting the aggregated results and underscores the need for more standardized approaches in future research.

This systematic review provides an in-depth analysis of the oral health care challenges that carers of dependent older adults, face. It highlights several key issues: the gap between education and practice, the persistence of barriers to adequate oral health care, and lack of health literacy among carers. The reviewed studies show that although carers recognize the importance of oral health and its link to systemic health, their ability to provide adequate care is often troubled by insufficient formal training, inadequate resources, and organizational challenges. Caregivers were primarily involved in brushing teeth and cleaning dentures but were less likely to perform more complex oral health tasks. Furthermore, despite these challenges, carers demonstrated a strong awareness of the need for oral care in older people, although their knowledge of oral health practices and conditions remained limited.

Results from studies using the Nursing Dental Coping Belief Scale (NDCBS) show a significant discrepancy between carers’ beliefs about their competence to provide oral care and the actual practices observed. Experienced carers often reported facing more challenges, possibly due to burnout or a mismatch between training and the demands of caring. The barriers identified across studies can be categorized into resident, organizational, and carer-related factors, each contributing to suboptimal oral health care.

The included studies showed that oral health care practices for dependent older adults are still inadequate, insufficient, and unsystematic. Although guidelines for appropriate oral health care exist (56, 57), training in oral and prosthetic hygiene has been shown to have a positive impact, and various oral health training programs for care providers working in geriatric settings have been described in the literature (58–62). However, a systematic review of strategies to improve oral health care showed that there is still a need to improve the strategies used to change oral health care behaviors, as providing general information seems to be successful in increasing oral health knowledge but does not necessarily improve oral health (63). In addition, another systematic review (64) showed that oral health education programs may indeed have a positive effect on oral hygiene in the older adult, although some limitations of the included studies were noted.

Therefore, caregivers need structured training programs that improve their knowledge and equip them with the skills and resources to effectively perform daily oral health tasks. Training programs can be more effective if they are tailored to the specific needs of caregivers in different settings and focus on practical training. In addition, such training should be regularly updated to reflect advances in oral health care for older people and integrated into the routine activities of nursing homes and care facilities. Dental professionals must actively participate in training and provide ongoing support, as this significantly improves caregivers’ confidence and competence in delivering oral health care.

In addition, the financial burden of dental care for nursing home residents remains a significant issue. Oral health care is often excluded from public health coverage, leaving residents to pay for treatment. This factor contributes to the neglect of oral health and increases the risk of significant oral disease. We must implement policy changes to integrate dental care into the broader health care framework for older people and provide financial support to reduce out-of-pocket costs for residents.

This systematic review was conducted according to PRISMA, a rigorous and widely recommended guideline that increases robustness and reduces reporting errors. In addition, an extensive literature search was conducted using a meticulous predefined protocol.

However, there are some limitations that need to be discussed. Most studies used a convenience sample of nursing homes in the study area, so the results may have been different if the other facilities had been included in the studies. In addition, only a few health care professionals from each sample site participated in the surveys. As a result, the small sample size limits the ability to extrapolate the data to the rest of the population and the ability to detect small differences between groups as statistically significant. Another limitation is the reliance on self-reported data, particularly from questionnaires and interviews, which can introduce various forms of bias. Carers may be motivated to give socially desirable answers, overestimating their level of training or the quality of care they provide. Recall bias is also a concern, as caregivers may have difficulty accurately recalling specific events or practices related to oral health care. In addition, the heterogeneity of the studies—ranging from differences in data collection methods (e.g., questionnaires vs. interviews) to differences in study populations (e.g., type of caregiver, setting, geographic location)—makes it difficult to draw firm conclusions about the generalisability of the findings. The lack of standardized measurement tools across studies makes it difficult to compare results, especially for complex constructs such as oral health knowledge and caregiver self-efficacy.

Future studies should focus on data representativeness and method standardization to ensure more homogeneous evidence-based results. The NDCBS is a standardized assessment tool that should be widely used. This information is extremely important for improving the oral health of nursing home residents and, consequently, their well-being and systemic health. It is also important for educating nursing home administrators about the improvements that can be made in oral health care.

The findings of this review support the proposal of several actionable strategies to address the barriers to providing oral health care for older adults: