Oral Hygiene Care of Older Adults and Caregiver Education: A Systematic Review

Abstract

There is a need to develop comprehensive guidelines to encourage the promotion of oral hygiene care among older adults and to assist caregivers in this endeavor, taking into consideration the specific challenges that arise from aging, comorbidities and caregiving. This review was conducted by searching across relevant literature from meta-databases including Academic Google, PubMed, Scielo and Scopus for studies published from 2020 to 2024. PRISMA guidelines were followed. We included articles that described oral hygiene methods, caregiver education and mechanization status of older adults. Common themes, best practices, and gaps in current guidelines were tracked using extracted and analyzed data. The review revealed multiple factors affecting the oral hygiene of older adults, with themes relating to physical impairment, cognitive dysfunction, and caregiver involvement. Highlighted between the approaches are individualized therapy for oral hygiene, caregiver education, and the use of technology to improve adherence to oral hygiene. Barriers like dental care access, underlying medical conditions complicating dental treatments, and cost considerations were identified. The findings emphasize the necessity of clear recommendations that can help caregivers and advance dental care for older adults.

1. Introduction

Public health faces escalating challenges because worldwide, population aging advances forward [1,2]. From the perspective of the current context, it is essential to aim for the preservation of a satisfactory oral health condition in the elderly population. For this reason, the United Nations and the World Health Organization (WHO) allocated the years between 2021 and 2023 as the Decade of Healthy Aging with an intent to encourage concerted action to promote longer, healthier lives [3].

Insufficient oral care among older adults not only affect oral health but also has far-reaching biological, psychological, social, and economic consequences [4,5]. From a biological standpoint, deficient oral hygiene may cause infections and chronic diseases, greatly impairing quality of life and personal autonomy [6,7]. Psychologically, this leads to depression and anxiety, compounding self-esteem issues [8]. Oral health reflects socioeconomic status, educational background and self-care habits. It shapes hygiene practices, self-esteem and social inclusion, while also exposing disparities in access to preventive care and essential treatments [8,9]. Furthermore, the economic loss of handling these affairs might be significant for both people and public health systems [7,10,11]. Improving their oral hygiene is a critical factor for healthy aging and richer quality of life among seniors.

The WHO defines people over 60 as older persons even if they show physical and mental decline due to any cause [3]. In certain countries, people start categorizing individuals as senior citizens at 65 because of social security norms regarding retirement and insurance benefits [12].

It is important to practice oral hygiene, which can be taken in order to prevent the mouth from being infected and unhygienic [13], and is essential to prevent oral and systemic disease that are more common among older people. Some of the care includes brushing and flossing and check-ups at the dentist for checks and cleanings [14].

Oral diseases can have a very unfavorable effect on general health, life quality, and the ability of older people to swallow and talk [15,16]. However, a number of older people have severe impairments, intellectual disability, and poor access to oral care that makes it difficult to practice good oral hygiene [17,18].

Caregivers are healthcare professionals, family members, friends, social workers or members of religious organizations who provide assistance at home, in the hospital, or other health institutions. They are also known as the people who are responsible for the patient [19].

The importance of supporting the oral hygiene of older adults is also extended to caregivers so that specific education and resources for this group are needed. Training caregivers is also crucial to make sure that older adults get the right oral care and can maintain good oral health. In this context, studies often highlight that oral care training for caregivers is inconsistent and underdeveloped [15,16,18]. Researchers emphasize the need for standardized, evidence-based training programs.

2. Objective, Focus and Scope of This Review

This systematic review intends to aggregate and synthesize the body of literature pertaining to oral hygiene practices among older adults and the education of their caregivers. The objective of this research is to emphasize key factors that affect oral hygiene, identify exemplary practices, and propose recommendations for forthcoming research initiatives.

In line with the requirements of a systematic review [20], a preliminary protocol was developed that included a comprehensive literature search, organized data extraction and steps to ensure internal reliability. The target audience for this review are healthcare professionals such as dentists, dental hygienists, nurses, and doctors who work with older adults. Additionally, it would also be appropriate for caregivers of older adults, whether they are family members, friends, or professionals providing care in home or healthcare settings. Public health organizations, researchers in the field of oral health organizations, researchers in the field of oral health, and those interested in promoting the health and well-being of older adults could also find this review suitable.

Through this review, the authors aspire to provide a comprehensive overview of the present knowledge in this field and to improve the oral health of the elderly population.

3. Materials and Methods

This systematic review protocol was registered with the International Prospective Register of Systematic Reviews PROSPERO (Registration number: CRD420251053701) and based on the Preferred Reporting Items for Systematic Reviews and Meta Analysis (PRISMA) 2020 guideline [21].

In this systematic review, three questions were addressed:

(1)

What is the impact of caregiver training on improving oral hygiene practices among the elderly population?

(2)

How does the level of caregiver training impact the effectiveness of oral hygiene procedures in older adults, considering their level of cognitive function and motor skills?

(3)

What educational strategies have been proven the most effective in improving the relationship between caregiver training and quality of oral hygiene care of older adults?

This review focused on the significance of an adequate oral hygiene care for older adults, highlighting the necessity for comprehensive education and training for caregivers in order to improve the overall oral health and well-being of this population.

3.1. Inclusion and Exclusion Criteria

Individual studies were included in the review if they (i)were peer-reviewed primary studies (e.g., randomized trials, observational studies, mix methods designs); (ii) reported on individuals 60 and older; (iii) pertained to oral hygiene methods, caregiver education and the mechanization status of older adults; (iv) were published in the English and Spanish language.

Studies were excluded if they (i) consist of non –peer- reviewed literature; (ii) reported on individuals under the age of 60; (iv) do not simultaneously address both oral hygiene strategies and either caregiver education programs or assistive technologies, (iii) were not written in the English and Spanish language; (v) were published as only abstracts or posters or were unpublished work. Figure 1 presented the inclusion and exclusion criteria for this review.

3.2. Search Strategy

The review was conducted by searching relevant literature from meta-databases, including Academic Google, PubMed, Scielo and Scopus for studies published from 2020 to 2024. Articles that described oral hygiene methods, caregiver education and the mechanization status of older adults were included.

Mechanization refers to the various levels of assistance provided by devices or technologies that support users in their daily activities. As individuals age, they frequently experience a decline in physical abilities and mental acuity, leading them to seek external assistance to accomplish their activities. Common themes, best practices, and gaps in current guidelines were identified through the extraction and analysis of data. In this research, we employed a strategic selection of keywords, including “aged”, “frail elderly”, “healthy aging”, “oral hygiene”, “oral health”, “oral medicine”, “caregivers”, “family member”, “nursing staff”, “education”, “assistive technology” and “assistive device”. Additionally, we utilized Boolean logical operators such as “AND”, and “OR” to refine our search and enhance the relevance of the retrieved literature. A summary of the MeSH terms and keywords used for the search strategy is presented in Table 1.

Table 1. Summary of the MeSH terms and keywords.

Database	MeSH Terms	Keywords
Academic Google	aged, oral hygiene, caregiver education	frail elderly, healthy aging, oral health, oral medicine, dentistry
PubMed	aged, oral hygiene, caregivers, dental care	family member, nursing, assistive, technology, assistive device, education
Scielo	older adult, oral hygiene, caregiver education	caregiver training, oral health promotion, elderly care
Scopus	aged, oral hygiene, oral health, caregivers	caregiver education, technology

3.3. Study Records

3.3.1. Data Management/Selection Process

Search results were exported to Endnote (Clarivate Analytics (US) LLC, London, UK) and duplicates removed. Records were then exported to Rayyan [22], whereby two independent reviewers screened all titles, abstracts, and full texts against the predetermined eligibility criteria. Any disagreements regarding inclusion were resolved through discussion between the two reviewers. When consensus was not reached, a third reviewer (A.N.) was consulted.

3.3.2. Data Extraction

Data were extracted by the independent reviewers using a predefined data extraction proforma. The form included the following information: author (s) and year of publication; aim and objectives; study design; results; conclusions; recommendations/gaps in research.

3.3.3. Data Synthesis

A synthesis was informed using the Arksey and O’Malley framework [23]. The six-stage framework was applied to this study as follows: identifying the research question; identifying relevant studies; study selection; charting de data; collating; summarizing and reporting the results. Results were summarized to present an overview of the evidence, and quantitative and qualitative analyses were used to describe study characteristics. These analyses allowed major themes to be identified and redefined (D.M.A., S.B. and A.N.) and gaps in the literature to be identified.

3.3.4. Assessment of Study Quality

The methodological quality of the studies included in this review was assessed using tools validated for each study design. The (Table 2) 2018 version of the Mixed Methods Appraisal Tool (MMAT) [24] was used for qualitative, quantitative, and mixed-methods studies and the Cochrane Risk of Bias tool (RoB-1) [25], from randomized controlled trials.

The search and selection process was thorough and based on clear criteria; however, a moderate risk of bias was identified due to language restrictions and exclusion of gray literature or unpublished studies. Three studies exhibited a high risk of bias, mainly due to lack randomization, no blinding and no control group. Five studies had moderate concerns due to quasi-experimental designs and incomplete reporting, and the heterogeneity of interventions and outcomes made direct comparisons and quantitative synthesis impossible.

Also, the prevalence of self-reported outcomes, short follow-up durations, and small sample sizes limited external validity and long-term effects. Selective reporting and publication bias were also noted.

The methodological quality and risk of bias for each included study was rated using a star system adapted from established tools [26]. This system considers factors such as study design, sample size, presence of control group, blinding, and completeness of data:

–

★★★★★ (five stars): High quality, low risk of bias; robust methodology (e.g., randomized controlled trials with proper randomization and blinding).

–

★★★★☆ (four stars): Good quality, moderate risk of bias; most methodological criteria met with minor limitations.

–

★★★☆☆ (three stars): Moderate quality, notable risk of bias; small sample size, no control group, or short follow-up.

–

★★☆☆☆ (two stars): Low quality, high risk of bias; significant methodological weaknesses (e.g., uncontrolled design, incomplete data).

–

★☆☆☆☆ (one star): Very low quality, very high risk of bias; not enough evidence to draw conclusions.

In addition to applying validated appraisal tools such as the MMAT and the Cochrane Risk of Bias tool, we carefully considered the inherent limitations of observational studies included in this review. Many relied heavily on self-reported outcomes, single-institution samples, or cross-sectional designs, which introduce risks of recall bias, selection bias, and limited external validity. By incorporating a star-based quality rating system, we aimed to transparently differentiate between high-quality randomized trials and studies with moderate to high risks of bias, particularly within the observational category.

In summary, the overall risk of bias in this review is moderate to high, so the findings are not very certain.

4. Results

The findings of this systematic review highlight critical gaps and opportunities in oral hygiene care for older adults and the role of caregiver education. By synthesizing evidence from 34 studies across diverse geographic and institutional settings, this review accentuates the interplay between systemic barriers, caregiver preparedness, and the efficacy of educational interventions (Figure 1). Below, these findings are contextualized within current literature, their broader implications are explored, and actionable guidelines for future research are proposed.

Figure 1. Flow diagram of the study selection, exclusion and inclusion within the systematic review (PRISMA) [21].

Table 2. Study characteristics of included studies.

Reference Year	Study Design	Setting	Country	Participants (n, Age, caregiver Type)	Intervention (+Technology/Comparator)	Key Results	Limitations	Quality/Risk of Bias
Aquilanti et al. [27]	Systematic review of studies on teledentistry	Community and domiciliary settings, residential aged care facilities	Various countries (studies from multiple settings internationally)	Elderly participants across included studies; sample sizes and caregiver types varied by study	Teledentistry interventions including remote consultations, telemonitoring, education, and oral health assessments; comparator usually usual care or no intervention	Teledentistry is feasible and can improve access to dental care for elderly populations - Potential to reduce unmet oral health needs - Positive impact on oral health outcomes and patient satisfaction reported in some studies	Heterogeneity of included studies and interventions - Limited high-quality RCTs - Variability in study designs and outcomes measured - Some studies with small sample sizes and methodological Limitations	★★★☆☆ Moderate quality due to heterogeneity and methodological limitations of included studies; moderate confidence in findings but limited by variability and few high-quality RCTs.
Brady et al. [28]	Pragmatic, multicenter, stepped wedge cluster randomized controlled trial (pilot)	4 stroke rehabilitation wards	Scotland, UK	325 patients (median age 76 years, range approx. 63–83), nursing staff (112 nurses)	Enhanced oral healthcare intervention: online training for nursing staff, oral health protocols, assessment tools, oral care equipment and products; Comparator: usual oral healthcare	No significant difference in stroke-associated pneumonia incidence (p = 0.62); no difference in dental plaque or oral health-related quality of life; intervention feasible and safe; poor oral healthcare documentation noted	Pilot study with small sample size; variability between sites; inability to blind staff and outcome assessors; poor oral healthcare documentation; limited power to detect differences in pneumonia.	★★★★☆ (solid design and appropriate analysis, with a moderate risk of bias mainly due to the impossibility of blinding and the need for careful analysis to control temporal trends).
Hernández-Santos and Díaz-García [29]	Intervention study with pre- and post-test design	Rest house for older adults	Mexico	6 older adults (all women), mean age 82.5 ± 9.7 years; caregivers (type not specified, likely informal or institutional)	Weekly educational sessions on oral health for caregivers; no technology reported; comparator: baseline (pre-intervention)	Oral hygiene improved by 33.72% measured by simplified oral hygiene index; significant positive impact of caregiver education on elderly oral hygiene	Small sample size; no control group; short follow-up; limited generalizability	★★★☆☆ (moderate risk of bias due to small sample size, lack of control group, and limited follow-up)
Girestam Croonquist et al. [30]	Randomized controlled trial (RCT), evaluator-blinded, open-ended design	9 nursing homes	Sweden	146 residents (mean age not specified, dependent older adults), caregivers: nursing home staff	Intervention: Monthly professional cleaning and individualized oral hygiene education by dental hygienists (RDHs). Comparator: usual daily oral care (self-care or assisted by nursing staff)	Significant improvements in oral hygiene (mucosal-plaque score, gingival bleeding), reduction in root caries in intervention group. Nursing staff showed improved knowledge and attitudes towards oral care after intervention	Follow-up limited to 6 months, possible bias due to lack of full blinding of participants and staff, limited generalizability to other countries or settings	★★★★☆ (good quality with a moderate risk of bias mainly due to the impossibility of complete blinding)
Zimmerman et al. [31]	Cluster randomized controlled trial (cluster RCT)	14 nursing homes (7 intervention, 7 control)	United States	2152 residents (mean age 79.4 years; 66.2% women; caregivers: nursing home staff)	No significant reduction in pneumonia incidence over 2 years (IRR 0.90, p = 0.27); however, significant reduction during first year in adjusted post hoc analysis (IRR 0.69, p = 0.03). Improved staff knowledge and attitudes towards oral care.	No significant reduction in pneumonia incidence over 2 years (IRR 0.90, p = 0.27); however, significant reduction during first year in adjusted post hoc analysis (IRR 0.69, p = 0.03). Improved staff knowledge and attitudes towards oral care	Lack of sustained effect at 2 years possibly due to challenges in maintaining intervention fidelity; inability to blind participants and staff; generalizability limited to similar settings	★★★★☆ (good quality with moderate risk of bias, mainly due to the impossibility of complete blinding and challenges in maintaining the intervention over the long term).
Díaz-Méndez and Huerta-Fernández. [32]	Protocol development/descriptive study	Long-term care facilities for older adults (ELEAM)	Chile	Institutionalized older adults (number and age not specified); caregivers and healthcare personnel	Oral hygiene protocol adapted for COVID-19 pandemic, including infection control measures, use of PPE, oral hygiene techniques to prevent aspiration pneumonia; no comparator	Provides detailed, practical hygiene protocol emphasizing prevention of aspiration pneumonia and infection control during COVID-19; highlights importance of caregiver training	No empirical data or evaluation of protocol effectiveness; descriptive only; no sample size or outcome measures	★☆☆☆☆ (very high risk of bias due to descriptive protocol design without empirical data or outcome evaluation).
Wu et al. [33]	Pilot randomized controlled feasibility study (two-group pretest-posttest design)	Community-dwelling older adults with cognitive impairment; recruited from memory clinic and caregiver support groups	United States	25 older adults (≥ 60 years) with mild cognitive impairment or mild dementia; along with their informal caregivers (care partners); Treatment Group 1 (n = 7), Treatment Group 2 (n = 18)	Treatment Group 1: education with brochure and electric toothbrush. Treatment Group 2: brochure, personalized care plan, 4 coaching sessions for caregivers, and electric toothbrush. No traditional control group.	- Low dropout rate. - Improvements in oral hygiene in both groups. - Group 2 showed greater reduction in plaque and gingivitis, and better overall oral health status compared to Group 1.	- Small sample size, especially in Group 1 (n = 7). - No traditional control group. - Non-blinded assessor, potential measurement bias. - Active components of the intervention are not clearly identified.	★★★☆☆ (moderate quality; pilot experimental study with small sample size, no blinding, and no control group)
Oliveira et al. [34]	Cross-sectional	Home visits by primary care teams	Brazil	238 homebound older adults; majority with informal caregivers, some with professional caregivers; age not specified	None (descriptive study, no intervention or comparator)	- High prevalence of oral health problems (edentulism, untreated caries, visible biofilm) - 45.5% required help with oral hygiene - 87% lived with caregivers but oral care was inconsistently provided - Only 16.3% received home dental visits	- Non-probabilistic sampling - No control or comparison group - Descriptive only, no causality - Limited generalizability (single region)	★★☆☆☆ Descriptive cross-sectional study with non-probabilistic sampling; no control group or formal bias assessment; limited generalizability and causal inference.
Godoy et al. [35]	Quantitative, observational, descriptive, cross-sectional study	Elderly long-term care facilities (ELEAM)	Chile (Antofagasta)	49 caregivers (all women); age not specified; formal caregivers in institutional setting	No intervention; assessment of oral health care beliefs using DCBS-sp questionnaire; no technology; comparator: none	36.7% had oral health training; 97.96% perceived need for training; caregivers with training showed significantly more favorable beliefs regarding internal locus of control and self-efficacy	Cross-sectional design limits causality; self-reported data; no intervention tested; limited generalizability outside context	★★★☆☆ (moderate risk of bias due to observational design and self-report measures).
Ryu et al. [36]	Before–After Interventional Study	Long-term care hospital	Japan	37 elderly inpatients (mean age 83.3), 29 registered nurses (mean age 45.2); Nurses performed oral care daily	Interprofessional oral care program	Reduced tongue microbes; improved awareness, protocol adherence	No control group; single-site; prior training	★★★★☆ (well-structured intervention with measured outcomes; lacks RCT design)
Boada- Cahueñas. [37]	Community-based intervention study	Geriatric center (Red Cross of Otavalo)	Ecuador	35 older adults (age not specified), 15 caregivers (type not specified)	Educational intervention with virtual platforms on gerontological nutrition and oral health; diet plans based on oral health status; comparator: baseline	85.3% of older adults had poor oral health; post-intervention, caregivers improved oral hygiene practices by 93%; diets adapted to oral health status (mostly semi-liquid)	Small sample size; limited demographic details; no control group; short follow-up	★★★☆☆ (moderate risk of bias due to small sample size, lack of control group, and limited follow-up).
Wagner et al. [38]	Mixed methods qualitative study with field interviews and literature review	Nursing homes	Germany, Austria, Portugal (collaborative study)	Nursing home caregiving staff (number not specified); elderly residents indirectly involved	Deployment of sensor-based oral-care adherence aid system and electric toothbrushes integrated into daily workflow	Caregivers welcomed the system; helped identify residents unable to perform adequate oral self-care; potential to improve oral care and reduce morbidity and hospitalizations; economic benefits with return on investment estimated at 1:2.5	Small sample size; initial reactions only (short-term); lack of quantitative outcome data on oral health improvements; limited generalizability	★★★☆☆ (moderate quality; qualitative design with limited sample and short follow-up; useful for understanding caregiver perspectives but limited empirical outcome data)
Edman and Wardh [39]	Cross-sectional survey	Home care and special accommodations (nursing homes),	Sweden	2167 care personnel; mean age 44.2 years; mostly assistant nurses and women; mix of experience levels	Nursing Dental Coping Beliefs Scale (N-DCBS) used to assess beliefs across 4 domains: Self-Efficacy, Internal/External Locus of Control, Oral Health Care Beliefs	Internal control higher in experienced staff; confidence high but practice inconsistent	High dropout; low consistency; regional limits	★★★☆ (broad sample, validated scale; but limited generalizability and measurement consistency)
Sigurdardottir et al. [40]	Cross-sectional survey	2 nursing homes	Iceland	109 caregivers (94% female, avg. age 38.5); care assistants, practical nurses, and registered nurses	No intervention; survey using Nursing Dental Coping Belief Scale (NDCBS), and questions on beliefs, education, and practices	Low training levels; care assistants’ main providers; low floss use; beliefs varied	Two homes; small sample; Iceland-only survey.	★★★☆☆ Moderate quality: findings are based on a small sample from only two nursing homes in Iceland. Self-report survey design may introduce response bias.
Alalshaikh et al. [41]	Cross-sectional survey study	Special needs centers, schools, and organizations	Saudi Arabia	186 caregivers; mostly female	No intervention; perceptions of oral & general health	High awareness; younger caregivers’ better awareness; support for dentist role	Self-report bias; convenience sample; limited region	★★★☆☆ (moderate; informative but limited generalizability)
An et al. [42]	Cross-sectional study	Tertiary hospital in Chenzhou, Hunan Province	China	317 nurses; Mean age: 32.25 years; 95.9% female; Mostly with ≥5 years of clinical experience and bachelor’s degrees	HeLD-14 & behavior questionnaire	Higher OHL linked to better behaviors; poor flossing & dental visits	Self-report bias; single site; interested participants may bias sample	★★★☆ (well-executed but limited in generalizability and causality)
Shirobe et al. [43]	Cluster-Randomized Controlled Trial	Dental Clinics	Japan	83 older adults (51 intervention, 32 control); mean age 78 years; caregiver type not specified	12-week oral frailty program vs. none	Improved motor skills, tongue pressure, and masticatory function in intervention group	High dropout rate; small sample size; short-term follow-up only	★★★☆ Moderate quality due to sample size and follow-up limitations
Balwanth and Singh [44]	Cross-sectional study	7 Long-term care facilities in eThekwini District	South Africa	188 formal caregivers; Majority female (96.8%); Mostly aged 30–42; 83.5% cared for elderly, rest for children or disabled adults	Self-reported KAP survey	High desire to improve knowledge; uncooperative residents as barrier; knowledge-attitude link	Self-report bias; COVID-19 restrictions	★★★☆ (methodologically sound but limited generalizability)
Cao et al. [45]	Cross-sectional survey	Community settings (urban & rural)	China	4218 community-dwelling older adults (aged ≥60); no caregivers included	No intervention; assessed oral health knowledge, attitudes, and practices in relation to frailty using structured questionnaire	Knowledge linked to frailty; urban/rural differences; attitudes protective	Self-report bias; no caregiver data; limited generalizability	★★★☆☆ Moderate (typical for small cross-sectional studies; informative but not generalizable)
Chau et al. [46]	Systematic review	Community & clinical settings (5 studies)	South Korea, Egypt, Australia, UK	422 total participants aged ≥60; no caregivers included	5 studies using mHealth (apps, web modules, SMS) to deliver oral health education vs. control groups or baselines	mHealth improved knowledge, behaviors; mixed clinical outcomes effectiveness across domains	High dropout; limited follow-up; adherence data lacking	★★★☆☆/Fair to moderate quality; systematic review with limited included studies. Dropout rates, lack of follow-up data, and poor reporting on intervention adherence affect reliability.
Smith et al. [47]	Randomized Controlled Trial (RCT)	Nursing home	Spain	45; ≥75 yo, dementia; Formal caregivers	Training + electric toothbrushes (app) vs. usual care	40% plaque reduction	Small sample size	★★★☆Moderate quality RCT., limited by very small sample size, lack of long-term follow-up, and unclear generalizability.
Idris et al. [48]	Qualitative (Constructivist Grounded Theory)	In-home aged care services	Australia (Perth, WA)	15; all aged ≥65 clients; 13 support workers, 2 case managers	No intervention; barriers/enablers to care	Barriers: priority, responsibility, affordability, system; Enablers: autonomy, integration, training	Small sample; limited generalizability; interview setting may bias	★★★☆☆Moderate quality based on qualitative reporting standards. Study provides valuable insights using grounded theory, but the small sample size, limited geographic setting bias limit generalizability.
Pahlevanynejad et al. [49]	Systematic review	Home care settings for elderly individuals	Various (studies included from multiple countries; review of international literature)	Elderly adults receiving home care; caregivers include informal (family) and formal caregivers; exact sample sizes vary across included studies	Personalized mobile health (mHealth) interventions including mobile apps, wearable devices, telemonitoring, and digital education tools designed to support elderly home care. Comparators varied or were absent depending on included studies.	- mHealth interventions showed benefits in improving self-management, health monitoring, and communication between elderly and caregivers. - Challenges included usability issues, digital literacy barriers, and privacy concerns. - Potential to enhance caregiver support and elderly care quality.	- Heterogeneity of included studies in terms of design, technologies, and outcomes. - Limited long-term follow-up data. - Variability in caregiver involvement and reporting. - Possible publication bias	★★★☆☆ (moderate quality; systematic review with some variability in included studies’ quality and methodology)
Bashirian et al. [50]	Systematic review of 23 interventional studies (17 RCTs, 6 quasi-experimental)	Various community, clinical, and institutional settings	Multiple countries (studies included from various countries)	Older adults >60 years; caregivers included in some studies; total sample sizes vary by included studies	Educational interventions targeting older adults and/or their caregivers; methods included lectures, group discussions, motivational interviewing, e-learning, booklets; comparators were usual care or no intervention.	Educational interventions significantly improved oral health knowledge, attitudes, behaviors, and oral health-related quality of life in older people; practical education was more common in caregiver-focused interventions; evidence supports effectiveness of education for both older adults and caregivers	Heterogeneity in intervention types and settings; variability in outcome measures; some studies of moderate quality; limited number of high-quality trials; lack of long-term follow-up in many studies.	★★★☆☆ (moderate quality with a moderate risk of bias, mainly due to heterogeneity in study designs and limitations in reporting and follow-up).
Belmonte et al. [51]	Qualitative study (content analysis)	Home care, post-hospital discharge	Brazil	Caregivers of older adults with oropharyngeal dysphagia recently discharged from hospital; number not specified; informal caregivers	Semi-structured interviews analyzed with IRaMuTeQ software; no technology intervention; descriptive of caregiver strategies	Identified three main strategy categories: safe food offering, oral hygiene care, and continuity of speech therapy follow-up; caregivers rely on tacit knowledge and effective transitional care	Sample size and participant details not fully specified; qualitative design limits generalizability; no quantitative outcomes	★★★☆☆Moderate risk of bias typical of qualitative studies; potential for subjective interpretation; limited transferability
								★★★★☆ Comprehensive systematic review with clear methodology; some included studies have variable quality; overall moderate risk of bias due to observational nature of most data.
Razzaq et al. [52]	Intervention study using data from the LENTO (Lifestyle, Nutrition, and Oral Health in Caregivers) intervention; mixed methods with pre/post assessment of oral health care service use among family caregivers and care recipients	Community and home settings in Eastern Finland; involving family caregivers and their older care recipients	Finland	Informal family caregivers (n = 125) and care recipients (n = 120), all aged 65 years or older, living in Eastern Finland. Caregivers are mostly informal/unpaid family members providing care at home.	Individually tailored preventive oral health intervention aimed at improving use of oral health care services by caregivers and care recipients. Intervention included education, counseling, and support tailored to participants’ needs. No explicit comparator group mentioned; pre/post comparison used.	- Increased use of oral health care services by both caregivers and care recipients after the intervention. - Positive changes in caregivers’ perceptions of oral health importance and self-reported oral care behaviors. - Intervention feasible and accepted by participants.	- Lack of randomized control group limits ability to attribute changes solely to intervention. - Possible self-report bias in use of services and behaviors. - Study conducted in a specific geographic and cultural context (Eastern Finland), which may limit generalizability. - Details on long-term sustainability of effects not reported.	★★★☆☆ (moderate quality; non-randomized intervention study with pre/post design, potential self-report bias, no control group)
Bøtchiær et al. [53]	Umbrela Review (Systematic Reviews, Meta-analyses, Scoping Review)	Nursing Homes	Multiple	up to 133,857; ≥65; nurses, staff, dentists	Professional care, mouthwash, education, nutrition	Professional care may reduce pneumonia; malnutrition & QoL linked to oral health; education effect unclear	High heterogeneity; few high-quality studies	★★☆☆☆ Low quality due to 14 of 17 included reviews not reporting risk of bias. GRADE: Mostly Very Low—some High (nutrition/OHRQoL).
Wong and Leung [54]	Quasi-experimental longitudinal study	Two long-term care institutions	Hong Kong SAR	40 total (20 intervention, 20 control); healthcare providers, majority female, avg. age ~38	Oral Health Educational Program (4 sessions: 2 theory, 2 skill demos) vs. usual care	Knowledge sustained; practice/attitude change non-significant	Small sample; 2 facilities; limited generalizability	★★★★☆/Low risk of bias; study used a clear quasi-experimental design with an intervention and control group, but quality is limited by small sample size, selection from only two facilities, and lack of randomization.
James et al. [55]	Mixed Method Study (Quantitative + Qualitative)	Old Age Homes	India	54 elderly, 54 caregivers; ≥60 yo; full-time caregivers	No intervention; caregiver perceptions and oral health status	Poor oral health; high DMFT; barriers: autonomy, finances, knowledge, time	Small sample; convenience sample; localized to Bengaluru	★★★☆☆Moderate (qualitative stronger; higher bias quantitative)
Dumbuya et al. [56]	Qualitative Study (Semi-structured Interviews)	Nursing Homes (10 sites, affiliated with UT Health San Antonio)	United States	19; caregivers & administrators; 20–69 yo	No intervention; in-person interviews	Caregivers confident but time-limited; administrators unsure; need more training	Small sample; convenience sampling; COVID-19 impact	★★★☆☆ (rigorous qualitative design, but lacks generalizability due to sampling)
Nitschke et al. [57]	Cross-sectional study	Multiple care settings	Germany	79 caregivers; mean age 37.5 (range 16–63); mostly nursing assistants and semi-skilled labor nurses	Assessment of caregiver knowledge, attitudes, and hopes regarding implementation of the German Expert Nursing Standard “Promotion of Oral Health in Nursing” (GENS-POHN); Pre-implementation evaluation	Positive attitudes; knowledge gaps identified	Small sample; limited region; residents not included	★★★☆☆ (moderate; observational design, but detailed pre-implementation evaluation)
Weening-Verbree et al. [58]	Cross-sectional explorative study	Home care nursing organizations	Netherlands	141 older adults; mean age 84 (SD 7.4); caregivers: home care nurses (HCNs) of varying training levels	Simplified Oral Indicator (SOI) by HCNs vs. OHAT-NL by dental hygienists and GOHAI-NL self-assessment	SOI sensitivity/specificity poor; weak correlation to other scales	Small sample; denture wearers overrepresented	★★★☆☆ (moderate quality; exploratory pilot study)
Salazar et al. [59]	Systematic review of 30 randomized clinical trials	Community and long-term care facilities	Multiple countries (not specified)	Dependent older adults (varied sample sizes across studies), including community-dwelling and institutionalized; caregiver types varied	Educational and non-educational oral health interventions; comparators included usual care or no intervention	Interventions may reduce dental plaque short-term (low certainty) - Limited evidence on long-term effectiveness - Only one study assessed oral health-related quality of life - No studies assessed changes in oral care system use	Heterogeneity of included studies - Low certainty of evidence - Limited long-term data - Few studies on community-dwelling older adults - Country not specified, limiting contextual detail	★★★☆☆ Moderate quality; risk of bias assessed with Cochrane tool; limitations due to study quality and imprecision

Note: The table illustrates the quality assessment for included studies and highlights specific methodological concerns such as small sample size, absence of blinding, or short follow-up period.

Table 2. Study characteristics of included studies.

Reference Year	Study Design	Setting	Country	Participants (n, Age, caregiver Type)	Intervention (+Technology/Comparator)	Key Results	Limitations	Quality/Risk of Bias
Aquilanti et al. [27]	Systematic review of studies on teledentistry	Community and domiciliary settings, residential aged care facilities	Various countries (studies from multiple settings internationally)	Elderly participants across included studies; sample sizes and caregiver types varied by study	Teledentistry interventions including remote consultations, telemonitoring, education, and oral health assessments; comparator usually usual care or no intervention	Teledentistry is feasible and can improve access to dental care for elderly populations - Potential to reduce unmet oral health needs - Positive impact on oral health outcomes and patient satisfaction reported in some studies	Heterogeneity of included studies and interventions - Limited high-quality RCTs - Variability in study designs and outcomes measured - Some studies with small sample sizes and methodological Limitations	★★★☆☆ Moderate quality due to heterogeneity and methodological limitations of included studies; moderate confidence in findings but limited by variability and few high-quality RCTs.
Brady et al. [28]	Pragmatic, multicenter, stepped wedge cluster randomized controlled trial (pilot)	4 stroke rehabilitation wards	Scotland, UK	325 patients (median age 76 years, range approx. 63–83), nursing staff (112 nurses)	Enhanced oral healthcare intervention: online training for nursing staff, oral health protocols, assessment tools, oral care equipment and products; Comparator: usual oral healthcare	No significant difference in stroke-associated pneumonia incidence (p = 0.62); no difference in dental plaque or oral health-related quality of life; intervention feasible and safe; poor oral healthcare documentation noted	Pilot study with small sample size; variability between sites; inability to blind staff and outcome assessors; poor oral healthcare documentation; limited power to detect differences in pneumonia.	★★★★☆ (solid design and appropriate analysis, with a moderate risk of bias mainly due to the impossibility of blinding and the need for careful analysis to control temporal trends).
Hernández-Santos and Díaz-García [29]	Intervention study with pre- and post-test design	Rest house for older adults	Mexico	6 older adults (all women), mean age 82.5 ± 9.7 years; caregivers (type not specified, likely informal or institutional)	Weekly educational sessions on oral health for caregivers; no technology reported; comparator: baseline (pre-intervention)	Oral hygiene improved by 33.72% measured by simplified oral hygiene index; significant positive impact of caregiver education on elderly oral hygiene	Small sample size; no control group; short follow-up; limited generalizability	★★★☆☆ (moderate risk of bias due to small sample size, lack of control group, and limited follow-up)
Girestam Croonquist et al. [30]	Randomized controlled trial (RCT), evaluator-blinded, open-ended design	9 nursing homes	Sweden	146 residents (mean age not specified, dependent older adults), caregivers: nursing home staff	Intervention: Monthly professional cleaning and individualized oral hygiene education by dental hygienists (RDHs). Comparator: usual daily oral care (self-care or assisted by nursing staff)	Significant improvements in oral hygiene (mucosal-plaque score, gingival bleeding), reduction in root caries in intervention group. Nursing staff showed improved knowledge and attitudes towards oral care after intervention	Follow-up limited to 6 months, possible bias due to lack of full blinding of participants and staff, limited generalizability to other countries or settings	★★★★☆ (good quality with a moderate risk of bias mainly due to the impossibility of complete blinding)
Zimmerman et al. [31]	Cluster randomized controlled trial (cluster RCT)	14 nursing homes (7 intervention, 7 control)	United States	2152 residents (mean age 79.4 years; 66.2% women; caregivers: nursing home staff)	No significant reduction in pneumonia incidence over 2 years (IRR 0.90, p = 0.27); however, significant reduction during first year in adjusted post hoc analysis (IRR 0.69, p = 0.03). Improved staff knowledge and attitudes towards oral care.	No significant reduction in pneumonia incidence over 2 years (IRR 0.90, p = 0.27); however, significant reduction during first year in adjusted post hoc analysis (IRR 0.69, p = 0.03). Improved staff knowledge and attitudes towards oral care	Lack of sustained effect at 2 years possibly due to challenges in maintaining intervention fidelity; inability to blind participants and staff; generalizability limited to similar settings	★★★★☆ (good quality with moderate risk of bias, mainly due to the impossibility of complete blinding and challenges in maintaining the intervention over the long term).
Díaz-Méndez and Huerta-Fernández. [32]	Protocol development/descriptive study	Long-term care facilities for older adults (ELEAM)	Chile	Institutionalized older adults (number and age not specified); caregivers and healthcare personnel	Oral hygiene protocol adapted for COVID-19 pandemic, including infection control measures, use of PPE, oral hygiene techniques to prevent aspiration pneumonia; no comparator	Provides detailed, practical hygiene protocol emphasizing prevention of aspiration pneumonia and infection control during COVID-19; highlights importance of caregiver training	No empirical data or evaluation of protocol effectiveness; descriptive only; no sample size or outcome measures	★☆☆☆☆ (very high risk of bias due to descriptive protocol design without empirical data or outcome evaluation).
Wu et al. [33]	Pilot randomized controlled feasibility study (two-group pretest-posttest design)	Community-dwelling older adults with cognitive impairment; recruited from memory clinic and caregiver support groups	United States	25 older adults (≥ 60 years) with mild cognitive impairment or mild dementia; along with their informal caregivers (care partners); Treatment Group 1 (n = 7), Treatment Group 2 (n = 18)	Treatment Group 1: education with brochure and electric toothbrush. Treatment Group 2: brochure, personalized care plan, 4 coaching sessions for caregivers, and electric toothbrush. No traditional control group.	- Low dropout rate. - Improvements in oral hygiene in both groups. - Group 2 showed greater reduction in plaque and gingivitis, and better overall oral health status compared to Group 1.	- Small sample size, especially in Group 1 (n = 7). - No traditional control group. - Non-blinded assessor, potential measurement bias. - Active components of the intervention are not clearly identified.	★★★☆☆ (moderate quality; pilot experimental study with small sample size, no blinding, and no control group)
Oliveira et al. [34]	Cross-sectional	Home visits by primary care teams	Brazil	238 homebound older adults; majority with informal caregivers, some with professional caregivers; age not specified	None (descriptive study, no intervention or comparator)	- High prevalence of oral health problems (edentulism, untreated caries, visible biofilm) - 45.5% required help with oral hygiene - 87% lived with caregivers but oral care was inconsistently provided - Only 16.3% received home dental visits	- Non-probabilistic sampling - No control or comparison group - Descriptive only, no causality - Limited generalizability (single region)	★★☆☆☆ Descriptive cross-sectional study with non-probabilistic sampling; no control group or formal bias assessment; limited generalizability and causal inference.
Godoy et al. [35]	Quantitative, observational, descriptive, cross-sectional study	Elderly long-term care facilities (ELEAM)	Chile (Antofagasta)	49 caregivers (all women); age not specified; formal caregivers in institutional setting	No intervention; assessment of oral health care beliefs using DCBS-sp questionnaire; no technology; comparator: none	36.7% had oral health training; 97.96% perceived need for training; caregivers with training showed significantly more favorable beliefs regarding internal locus of control and self-efficacy	Cross-sectional design limits causality; self-reported data; no intervention tested; limited generalizability outside context	★★★☆☆ (moderate risk of bias due to observational design and self-report measures).
Ryu et al. [36]	Before–After Interventional Study	Long-term care hospital	Japan	37 elderly inpatients (mean age 83.3), 29 registered nurses (mean age 45.2); Nurses performed oral care daily	Interprofessional oral care program	Reduced tongue microbes; improved awareness, protocol adherence	No control group; single-site; prior training	★★★★☆ (well-structured intervention with measured outcomes; lacks RCT design)
Boada- Cahueñas. [37]	Community-based intervention study	Geriatric center (Red Cross of Otavalo)	Ecuador	35 older adults (age not specified), 15 caregivers (type not specified)	Educational intervention with virtual platforms on gerontological nutrition and oral health; diet plans based on oral health status; comparator: baseline	85.3% of older adults had poor oral health; post-intervention, caregivers improved oral hygiene practices by 93%; diets adapted to oral health status (mostly semi-liquid)	Small sample size; limited demographic details; no control group; short follow-up	★★★☆☆ (moderate risk of bias due to small sample size, lack of control group, and limited follow-up).
Wagner et al. [38]	Mixed methods qualitative study with field interviews and literature review	Nursing homes	Germany, Austria, Portugal (collaborative study)	Nursing home caregiving staff (number not specified); elderly residents indirectly involved	Deployment of sensor-based oral-care adherence aid system and electric toothbrushes integrated into daily workflow	Caregivers welcomed the system; helped identify residents unable to perform adequate oral self-care; potential to improve oral care and reduce morbidity and hospitalizations; economic benefits with return on investment estimated at 1:2.5	Small sample size; initial reactions only (short-term); lack of quantitative outcome data on oral health improvements; limited generalizability	★★★☆☆ (moderate quality; qualitative design with limited sample and short follow-up; useful for understanding caregiver perspectives but limited empirical outcome data)
Edman and Wardh [39]	Cross-sectional survey	Home care and special accommodations (nursing homes),	Sweden	2167 care personnel; mean age 44.2 years; mostly assistant nurses and women; mix of experience levels	Nursing Dental Coping Beliefs Scale (N-DCBS) used to assess beliefs across 4 domains: Self-Efficacy, Internal/External Locus of Control, Oral Health Care Beliefs	Internal control higher in experienced staff; confidence high but practice inconsistent	High dropout; low consistency; regional limits	★★★☆ (broad sample, validated scale; but limited generalizability and measurement consistency)
Sigurdardottir et al. [40]	Cross-sectional survey	2 nursing homes	Iceland	109 caregivers (94% female, avg. age 38.5); care assistants, practical nurses, and registered nurses	No intervention; survey using Nursing Dental Coping Belief Scale (NDCBS), and questions on beliefs, education, and practices	Low training levels; care assistants’ main providers; low floss use; beliefs varied	Two homes; small sample; Iceland-only survey.	★★★☆☆ Moderate quality: findings are based on a small sample from only two nursing homes in Iceland. Self-report survey design may introduce response bias.
Alalshaikh et al. [41]	Cross-sectional survey study	Special needs centers, schools, and organizations	Saudi Arabia	186 caregivers; mostly female	No intervention; perceptions of oral & general health	High awareness; younger caregivers’ better awareness; support for dentist role	Self-report bias; convenience sample; limited region	★★★☆☆ (moderate; informative but limited generalizability)
An et al. [42]	Cross-sectional study	Tertiary hospital in Chenzhou, Hunan Province	China	317 nurses; Mean age: 32.25 years; 95.9% female; Mostly with ≥5 years of clinical experience and bachelor’s degrees	HeLD-14 & behavior questionnaire	Higher OHL linked to better behaviors; poor flossing & dental visits	Self-report bias; single site; interested participants may bias sample	★★★☆ (well-executed but limited in generalizability and causality)
Shirobe et al. [43]	Cluster-Randomized Controlled Trial	Dental Clinics	Japan	83 older adults (51 intervention, 32 control); mean age 78 years; caregiver type not specified	12-week oral frailty program vs. none	Improved motor skills, tongue pressure, and masticatory function in intervention group	High dropout rate; small sample size; short-term follow-up only	★★★☆ Moderate quality due to sample size and follow-up limitations
Balwanth and Singh [44]	Cross-sectional study	7 Long-term care facilities in eThekwini District	South Africa	188 formal caregivers; Majority female (96.8%); Mostly aged 30–42; 83.5% cared for elderly, rest for children or disabled adults	Self-reported KAP survey	High desire to improve knowledge; uncooperative residents as barrier; knowledge-attitude link	Self-report bias; COVID-19 restrictions	★★★☆ (methodologically sound but limited generalizability)
Cao et al. [45]	Cross-sectional survey	Community settings (urban & rural)	China	4218 community-dwelling older adults (aged ≥60); no caregivers included	No intervention; assessed oral health knowledge, attitudes, and practices in relation to frailty using structured questionnaire	Knowledge linked to frailty; urban/rural differences; attitudes protective	Self-report bias; no caregiver data; limited generalizability	★★★☆☆ Moderate (typical for small cross-sectional studies; informative but not generalizable)
Chau et al. [46]	Systematic review	Community & clinical settings (5 studies)	South Korea, Egypt, Australia, UK	422 total participants aged ≥60; no caregivers included	5 studies using mHealth (apps, web modules, SMS) to deliver oral health education vs. control groups or baselines	mHealth improved knowledge, behaviors; mixed clinical outcomes effectiveness across domains	High dropout; limited follow-up; adherence data lacking	★★★☆☆/Fair to moderate quality; systematic review with limited included studies. Dropout rates, lack of follow-up data, and poor reporting on intervention adherence affect reliability.
Smith et al. [47]	Randomized Controlled Trial (RCT)	Nursing home	Spain	45; ≥75 yo, dementia; Formal caregivers	Training + electric toothbrushes (app) vs. usual care	40% plaque reduction	Small sample size	★★★☆Moderate quality RCT., limited by very small sample size, lack of long-term follow-up, and unclear generalizability.
Idris et al. [48]	Qualitative (Constructivist Grounded Theory)	In-home aged care services	Australia (Perth, WA)	15; all aged ≥65 clients; 13 support workers, 2 case managers	No intervention; barriers/enablers to care	Barriers: priority, responsibility, affordability, system; Enablers: autonomy, integration, training	Small sample; limited generalizability; interview setting may bias	★★★☆☆Moderate quality based on qualitative reporting standards. Study provides valuable insights using grounded theory, but the small sample size, limited geographic setting bias limit generalizability.
Pahlevanynejad et al. [49]	Systematic review	Home care settings for elderly individuals	Various (studies included from multiple countries; review of international literature)	Elderly adults receiving home care; caregivers include informal (family) and formal caregivers; exact sample sizes vary across included studies	Personalized mobile health (mHealth) interventions including mobile apps, wearable devices, telemonitoring, and digital education tools designed to support elderly home care. Comparators varied or were absent depending on included studies.	- mHealth interventions showed benefits in improving self-management, health monitoring, and communication between elderly and caregivers. - Challenges included usability issues, digital literacy barriers, and privacy concerns. - Potential to enhance caregiver support and elderly care quality.	- Heterogeneity of included studies in terms of design, technologies, and outcomes. - Limited long-term follow-up data. - Variability in caregiver involvement and reporting. - Possible publication bias	★★★☆☆ (moderate quality; systematic review with some variability in included studies’ quality and methodology)
Bashirian et al. [50]	Systematic review of 23 interventional studies (17 RCTs, 6 quasi-experimental)	Various community, clinical, and institutional settings	Multiple countries (studies included from various countries)	Older adults >60 years; caregivers included in some studies; total sample sizes vary by included studies	Educational interventions targeting older adults and/or their caregivers; methods included lectures, group discussions, motivational interviewing, e-learning, booklets; comparators were usual care or no intervention.	Educational interventions significantly improved oral health knowledge, attitudes, behaviors, and oral health-related quality of life in older people; practical education was more common in caregiver-focused interventions; evidence supports effectiveness of education for both older adults and caregivers	Heterogeneity in intervention types and settings; variability in outcome measures; some studies of moderate quality; limited number of high-quality trials; lack of long-term follow-up in many studies.	★★★☆☆ (moderate quality with a moderate risk of bias, mainly due to heterogeneity in study designs and limitations in reporting and follow-up).
Belmonte et al. [51]	Qualitative study (content analysis)	Home care, post-hospital discharge	Brazil	Caregivers of older adults with oropharyngeal dysphagia recently discharged from hospital; number not specified; informal caregivers	Semi-structured interviews analyzed with IRaMuTeQ software; no technology intervention; descriptive of caregiver strategies	Identified three main strategy categories: safe food offering, oral hygiene care, and continuity of speech therapy follow-up; caregivers rely on tacit knowledge and effective transitional care	Sample size and participant details not fully specified; qualitative design limits generalizability; no quantitative outcomes	★★★☆☆Moderate risk of bias typical of qualitative studies; potential for subjective interpretation; limited transferability
								★★★★☆ Comprehensive systematic review with clear methodology; some included studies have variable quality; overall moderate risk of bias due to observational nature of most data.
Razzaq et al. [52]	Intervention study using data from the LENTO (Lifestyle, Nutrition, and Oral Health in Caregivers) intervention; mixed methods with pre/post assessment of oral health care service use among family caregivers and care recipients	Community and home settings in Eastern Finland; involving family caregivers and their older care recipients	Finland	Informal family caregivers (n = 125) and care recipients (n = 120), all aged 65 years or older, living in Eastern Finland. Caregivers are mostly informal/unpaid family members providing care at home.	Individually tailored preventive oral health intervention aimed at improving use of oral health care services by caregivers and care recipients. Intervention included education, counseling, and support tailored to participants’ needs. No explicit comparator group mentioned; pre/post comparison used.	- Increased use of oral health care services by both caregivers and care recipients after the intervention. - Positive changes in caregivers’ perceptions of oral health importance and self-reported oral care behaviors. - Intervention feasible and accepted by participants.	- Lack of randomized control group limits ability to attribute changes solely to intervention. - Possible self-report bias in use of services and behaviors. - Study conducted in a specific geographic and cultural context (Eastern Finland), which may limit generalizability. - Details on long-term sustainability of effects not reported.	★★★☆☆ (moderate quality; non-randomized intervention study with pre/post design, potential self-report bias, no control group)
Bøtchiær et al. [53]	Umbrela Review (Systematic Reviews, Meta-analyses, Scoping Review)	Nursing Homes	Multiple	up to 133,857; ≥65; nurses, staff, dentists	Professional care, mouthwash, education, nutrition	Professional care may reduce pneumonia; malnutrition & QoL linked to oral health; education effect unclear	High heterogeneity; few high-quality studies	★★☆☆☆ Low quality due to 14 of 17 included reviews not reporting risk of bias. GRADE: Mostly Very Low—some High (nutrition/OHRQoL).
Wong and Leung [54]	Quasi-experimental longitudinal study	Two long-term care institutions	Hong Kong SAR	40 total (20 intervention, 20 control); healthcare providers, majority female, avg. age ~38	Oral Health Educational Program (4 sessions: 2 theory, 2 skill demos) vs. usual care	Knowledge sustained; practice/attitude change non-significant	Small sample; 2 facilities; limited generalizability	★★★★☆/Low risk of bias; study used a clear quasi-experimental design with an intervention and control group, but quality is limited by small sample size, selection from only two facilities, and lack of randomization.
James et al. [55]	Mixed Method Study (Quantitative + Qualitative)	Old Age Homes	India	54 elderly, 54 caregivers; ≥60 yo; full-time caregivers	No intervention; caregiver perceptions and oral health status	Poor oral health; high DMFT; barriers: autonomy, finances, knowledge, time	Small sample; convenience sample; localized to Bengaluru	★★★☆☆Moderate (qualitative stronger; higher bias quantitative)
Dumbuya et al. [56]	Qualitative Study (Semi-structured Interviews)	Nursing Homes (10 sites, affiliated with UT Health San Antonio)	United States	19; caregivers & administrators; 20–69 yo	No intervention; in-person interviews	Caregivers confident but time-limited; administrators unsure; need more training	Small sample; convenience sampling; COVID-19 impact	★★★☆☆ (rigorous qualitative design, but lacks generalizability due to sampling)
Nitschke et al. [57]	Cross-sectional study	Multiple care settings	Germany	79 caregivers; mean age 37.5 (range 16–63); mostly nursing assistants and semi-skilled labor nurses	Assessment of caregiver knowledge, attitudes, and hopes regarding implementation of the German Expert Nursing Standard “Promotion of Oral Health in Nursing” (GENS-POHN); Pre-implementation evaluation	Positive attitudes; knowledge gaps identified	Small sample; limited region; residents not included	★★★☆☆ (moderate; observational design, but detailed pre-implementation evaluation)
Weening-Verbree et al. [58]	Cross-sectional explorative study	Home care nursing organizations	Netherlands	141 older adults; mean age 84 (SD 7.4); caregivers: home care nurses (HCNs) of varying training levels	Simplified Oral Indicator (SOI) by HCNs vs. OHAT-NL by dental hygienists and GOHAI-NL self-assessment	SOI sensitivity/specificity poor; weak correlation to other scales	Small sample; denture wearers overrepresented	★★★☆☆ (moderate quality; exploratory pilot study)
Salazar et al. [59]	Systematic review of 30 randomized clinical trials	Community and long-term care facilities	Multiple countries (not specified)	Dependent older adults (varied sample sizes across studies), including community-dwelling and institutionalized; caregiver types varied	Educational and non-educational oral health interventions; comparators included usual care or no intervention	Interventions may reduce dental plaque short-term (low certainty) - Limited evidence on long-term effectiveness - Only one study assessed oral health-related quality of life - No studies assessed changes in oral care system use	Heterogeneity of included studies - Low certainty of evidence - Limited long-term data - Few studies on community-dwelling older adults - Country not specified, limiting contextual detail	★★★☆☆ Moderate quality; risk of bias assessed with Cochrane tool; limitations due to study quality and imprecision

Note: The table illustrates the quality assessment for included studies and highlights specific methodological concerns such as small sample size, absence of blinding, or short follow-up period.

5. Discussion

The evidence gathered in this systematic review underscores the critical role of ongoing education for both formal and informal caregivers in enhancing oral hygiene among older adults. In particular, the study by Girestam Croonquist et al. [30] demonstrated that these educational interventions lead to significant reductions in dental plaque and gingival bleeding, alongside substantial increases in caregiver knowledge and self-efficacy. Hernández-Santos and Díaz-García [29] found comparable results; their research showed that weekly educational sessions led to oral hygiene scores improving by 33.72%.

In this context, several studies provide concrete examples of effective individualized strategies. For instance, Girestam Croonquist et al. [30] reported that monthly professional cleaning combined with targeted caregiver education significantly improved mucosal-plaque scores, gingival bleeding, and root caries incidence among nursing home residents. Similarly, Wu et al. [33] demonstrated that personalized caregiver coaching sessions, supported by electric toothbrushes, led to greater reductions in plaque and gingivitis among older adults with cognitive impairment compared to basic educational materials alone. These examples highlight that individualized, context-sensitive interventions can translate into measurable improvements in oral health outcomes for older adults.

Currently, smart devices and teledentistry, along with other emerging technologies, are reshaping geriatric dental care by providing greater access to monitoring and attending to one’s oral health care. [27,38,47]. Despite the progress we’ve made, there are still significant challenges to overcome. These include limited access to broadband, a high turnover rate in the workforce, and a lack of widely accepted organizational procedures, all of which can weaken the long-term effectiveness of these ongoing changes [28,31,49].

From an economic perspective, these educational and technological interventions validate a favorable return on investment. Wagner et al. [38] estimate that for every monetary unit invested in technological systems and caregiver training, up to 1:2.5 units can be saved by preventing morbidity and avoidable hospitalizations. These findings reinforce the concept that prevention and caregiver education in oral hygiene are cost-effective investments that reduce both direct and indirect costs for individuals and public health systems [48,59].

Even though there are some enormous advantages, significant challenges persist related to inequities in funding, limited insurance coverage for dental care in older adults, and insufficient prioritization of oral health in public policies, which hinder equitable implementation and access to these interventions [28,48]. Many of the studies on this topic do not include a thorough cost-effectiveness analyses or long-term follow-up data which makes it hard to measure potential economic savings accurately [59].

Additionally, older adults living institutions often face cognitive and physical challenges, and different levels of digital skills among caregivers create obstacles. This means that it is needed to create specific interventions that fit the unique cultural and personal requirements of each situation [44,48]. From a research perspective, most of the studies have limitations such as small sample sizes, short follow-up times, and a lack of control groups. These issues make it difficult to apply the findings more broadly and highlight the need for more detailed studies that involve multiple centers and take place over a longer period [28,59].

Moreover, improving oral hygiene for older adults relies heavily on strong support from institutions. This includes ongoing training programs, regular supervisions and clear guidelines to help ensure that best practice are followed and monitored [37,46,54]. To achieve both clinical and economic benefits while promoting fair oral health for this vulnerable group we must enhance interdisciplinary caregiver training to make technology more accessible and strengthen institutional resources.

The findings of this review underscore the necessity of developing a specific curriculum for healthcare professionals and auxiliary staff who care for older adults. Training modules should address not only clinical oral hygiene techniques, but also behavioral management for patients with cognitive impairment, use of assistive technologies, and interdisciplinary collaboration in geriatric care. A standardized curriculum integrated into medical, nursing, and caregiver education would strengthen professional preparedness, reduce variability in practice, and align with the WHO Decade of Healthy Aging goals.

Technological tools such as teledentistry, mobile health applications, and sensor-based adherence systems hold considerable promise in bridging gaps in oral health care for older adults, particularly by enhancing monitoring, communication, and accessibility [60,61]. However, their broader implementation faces multiple challenges. Previous studies (e.g., [18,62]) have documented barriers such as high operational costs, insufficient institutional encouragement, concerns about patient privacy and data security, poor internet connectivity, and language or communication challenges. Additional obstacles include a lack of the necessary digital skills among older adults and caregivers, limited teledentistry infrastructure in low-resource settings, and resistance among some dental professionals to integrate these technologies into routine practice [18]. Beyond technological hurdles, socioeconomic inequalities strongly influence both caregiver education and access to dental care: lower-income families may struggle with affordability, while caregivers with limited education may face difficulties engaging with digital platforms or understanding preventive guidelines. These findings suggest that for technological interventions to be widely and equitably adopted, policies must address affordability through subsidies or insurance coverage, improve digital infrastructure, and provide culturally tailored training programs to enhance digital literacy among caregivers and older adults.

While heterogeneity in health conditions among older adults makes a single universal protocol challenging, there is a strong case for establishing a standardized preventive framework for people aged 65 and older. This framework should recommend more frequent preventive dental visits (every 3–6 months), individualized oral hygiene plans, and integration of assistive technologies to address functional limitations. Standardized recommendations can serve as a baseline, while remaining adaptable to comorbidities, care-dependency levels, and cultural contexts, ensuring that older adults receive both consistent and personalized care.

A critical examination of methodological quality reveals that while randomized controlled trials provided stronger evidence for caregiver training and oral hygiene interventions, the majority of observational studies were constrained by small sample sizes, short follow-up durations, and reliance on self-report data. These limitations weaken causal inferences and reduce the generalizability of findings across different populations and care settings. Nevertheless, such studies remain valuable in highlighting contextual barriers, caregiver perceptions, and cultural considerations that may not be fully captured in experimental designs. Recognizing these trade-offs is essential for interpreting the strength and scope of the evidence base.

Moreover, at the study and outcome level, the included studies varied in design, sample size, and methodological rigor, which may introduce heterogeneity in the results. As highlighted in our risk of bias assessment, some studies carried moderate or high risk of bias, and their findings should be interpreted with caution. At the review level, despite a comprehensive search strategy, the possibility of incomplete retrieval of relevant studies cannot be excluded, particularly unpublished or non-English research. Furthermore, reporting bias may have influenced the available evidence, as studies with positive findings are more likely to be published. These limitations underscore the need for cautious interpretation of our synthesis and highlight the importance of conducting further high-quality, well-reported research in this area.

6. Conclusions

The oral health of the elderly is a challenge to take care of, influenced by several health problems and the lack of sufficient support. Dentists or healthcare workers should give individualized care to promote oral health care education, while also exploring technology use. Barriers to effective oral hygiene care includes limited access to dental care, various comorbidities, and costs associated with care.

Caregiver training is crucial for the oral hygiene of older adults. Future research should include study designs and outcome measures that are relevant to actual clinical practice, culturally appropriate, and make a lasting contribution to the field. Demonstrating the leadership required from the dental professional in promoting education and protocols alongside advocating for policies will empower future older adults to decrease health disparities and promote health and active aging.

Looking ahead, future research should build on the findings of this review by addressing the methodological and contextual gaps identified. Well-designed multicenter randomized controlled trials with larger and more diverse populations are needed to provide stronger evidence on the effectiveness of caregiver education and individualized oral hygiene strategies. Studies should also incorporate longer follow-up periods to evaluate the sustainability of interventions over time, as well as cost-effectiveness analyses to assess their economic feasibility. Furthermore, research should explore the integration of technological tools—such as teledentistry, mobile health applications, and sensor-based adherence systems—while paying close attention to barriers related to digital literacy, infrastructure, and socioeconomic inequalities. Cross-cultural and interdisciplinary investigations could offer valuable insights into how caregiver education and oral hygiene interventions can be adapted to diverse care settings and health systems, ultimately advancing equitable and sustainable oral health for older adults.

Despite advances in this field, several gaps in knowledge remain. There is a lack of longitudinal studies that can evaluate the sustainability of caregiver education and oral hygiene interventions over time. Cost-effectiveness analyses are scarce, limiting the ability of policymakers to prioritize investments in preventive oral health for older adults. Additionally, most studies focus on high-income countries, leaving low-resource and culturally diverse contexts underrepresented. The evaluation of standardized caregiver curricula across different healthcare professions is also limited, despite evidence of significant knowledge gaps. Finally, research is needed on how to implement and scale up teledentistry and digital tools in ways that address barriers such as affordability, digital literacy, and professional acceptance. Addressing these gaps will be essential to advancing equitable, evidence-based oral health care for older adults in the coming years.

The PRISMA 2020 checklist for systematic reviews has been completed and is provided as Supplementary Materials.