Assessing oral health-related quality of life and the application of Assessing oral health-related quality of life and the application of silver diamine fluoride (SDF) in arresting caries among older silver diamine fluoride (SDF) in arresting caries among older adults adults

Background : This study aimed to evaluate the impact of oral health problems on oral health-related quality of life (OHRQoL) and assess the effectiveness of the application of 38% silver diamine ﬂ uoride (SDF) solution in arresting dental surface caries among the older adults. Methods : This study assessed the oral impact on daily performance (OIDP) scores and evaluated the percentage of arrested caries and patient satisfaction levels before and after receiving SDF treatment among older, community-dwelling adults attending the Diabetes Mellitus Clinic under the care of Bangkok Public Health Center 5. Results : In total, 42.9% of 49 participants encountered a minimum of one instance of oral discomfort due to signi ﬁ cant hypersensitivity and periodontal disease. The OHRQoL exhibited no alteration during the average 15-months of follow-up, staying at 53.6%. The results also show the remarkably high and stable rates of caries arrest (91.7%) after the application of 38% SDF without adverse effects. Conclusion : Due to the existence of oral health problem and negative health impacts, healthcare providers should focus on identifying vulnerable populations and providing targeted interventions to improve oral health outcomes in these groups. Considering the caries arrest outcomes and adverse effects of SDF, health professionals should consider promoting the use of SDF as a non-invasive and effective treatment option, especially for older adults with carious lesions.


Introduction
D ental caries remains a prevalent oral health issue among the elderly population worldwide.The prevalence of dental caries in the elderly can vary depending on the region, socioeconomic status, and access to dental care.According to data from the World Health Organization (WHO) and other research studies [1], the prevalence of dental caries in the elderly (aged 65 years and older) ranges from approximately 20%e90% globally.Data from the eighth Thailand National Oral Health Survey (TNOHS) showed that 52.6% of adults between 60 and 74 years old had untreated caries, 16.5% had primary root caries [2].Untreated caries could have serious consequences such as dental pain, difficulty chewing, poor appetite, weight loss, sleep disturbance, and poor school performance [3,4].Therefore, untreated caries could influence the patient's oral health-related quality of life (OHRQoL) [3,4].
Dental fillings are the prevailing treatment for dental caries.Nevertheless, non-invasive methods like fluoride application, anti-caries agents, and silver diamine fluoride (SDF) can be utilized for treating early carious lesions [5].Nowadays, there is a growing emphasis on minimally invasive approaches for treating active caries with the nonsurgical treatment.Silver diamine fluoride is a topical fluoride which has emerged as a fascinating alternative for managing untreated caries lesions on root surfaces, in furcations, and at the crown margin in older adults.When active caries are treated with SDF (silver diamine fluoride), it typically transforms into arrested caries, characterized by a brown or black appearance.Arrested caries are hard, glossy, and non-progressive.It effectively prevents further demineralization and supports the remineralization process of the tooth [6].Additionally, silver diamine fluoride (SDF) is known for its affordability and user-friendly application.It has proven effective in halting dentin caries progression in primary teeth among young children [7e12], and for preventing and arresting the development of root caries lesions in older adults [13e15].
Primary healthcare centers are the places which provide comprehensive integrated healthcare services.Globally, non-communicable diseases like cardiovascular disease, hypertension, cancer and diabetes are increasingly common among the elderly population.These conditions are rapidly emerging as the primary contributors to both disability and mortality rates [4].Improper behaviour is a common risk factor shared by chronic diseases and many oral diseases [16].To address the worldwide challenges posed by aging populations, the World Health Organization (WHO) has advised national public health programs to integrate oral health promotion and disease prevention, utilizing the common risk factors approach [1].The practice of dentistry should include monitoring and screening for chronic diseases, such as diabetes, and hypertension, to achieve successful patient management of complex dental problems, such as tooth loss, dental caries, and periodontal disease.
In Thailand, few available studies have investigated the association between general health, oral health, and QoL among older adults, along with the integration of oral health preventive care [17,18].Therefore, this study aimed to evaluate the impact of oral health problems on OHRQoL among older adults attending a Primary Health Center in Bangkok.We also had the overarching aim of the evaluating the effectiveness of an application of 38% SDF solution in arresting dental surface caries among the older adults.

Study design and settings
This prospective study was conducted at a single center.The study population were all communitydwelling, older adults attending the Diabetes Mellitus Clinic under the care of Bangkok Public Health Center 5, which serves as a primary healthcare facility in Thailand.This center caters to a substantial population, including 46,601 individuals residing in 4760 households, primarily in the Patumwan district of Bangkok.The center is known for its collaborative efforts between medical and dental professionals in implementing integrated oral health programs for patients with metabolic syndromes and providing comprehensive care for older adults.The center's services extend to regional and remote communities as well.Participants were recruited for this study between December 2020 and March 2021.The study included older adults aged between 60 and 90 years who were proficient in communicating in Thai.The exclusion criteria for this study involved elderly individuals with significantly affected salivary gland function caused by disease, medication, or treatment (e.g., head and neck region radiotherapy), as well as those with silver allergies.The subjects comprised of 49 elderly individuals.All participants received detailed information regarding the study design, risks, and benefits associated with silver diamine fluoride (SDF) application.The study also involved explaining the various study forms to ensure their understanding.All participants provided their informed consent before participating in this study.

Data collection 2.2.1. Questionnaire survey
Upon the participant's agreement to participate in the program, the questionnaire was administered.Face and content validity of the questionnaire was created and adjusted by experts.At the beginning of the study, a single examiner conducted a questionnaire-guided interview to collect information on the older adult's demographic background, their OHR-QoL and satisfaction after using SDF application.Satisfaction focuses on the patient's contentment with dental care, while OHRQoL is a broader measure that evaluates the impact of oral health on an individual's overall quality of life.Both satisfaction and OHRQoL were measured at the same time at follow-up.Understanding both aspects helps identify areas for improvement in dental care delivery and tailor interventions to enhance the overall oral health experience and quality of life of older adults.
The development of the Oral Impacts on Daily Performance (OIDP) inventory is one of several selfreported inventories designed to evaluate OHRQoL by measuring the negative effects that oral conditions.OIDP which was developed by Adulyanon et al. [17] has been shown to be applicable to older adult populations in Thailand.The OIDP index contains eight items corresponding to three domains: 1) physical, consisting of three items (chewing and enjoying food, talking and pronouncing clearly, and cleaning teeth), 2) psychological, consisting of three items (good sleep without disturbances, being able to smile without embarrassment, and maintaining usual emotional state without being irritable), and 3) social, consisting of two items (carrying out a major work or social role and enjoying contact with people).The prevalence of OIDP was measured by calculating the percentage of patients who reported experiencing at least one oral impact on their daily activities within the past three months.The frequency of each impact varied from 0 (never affected) to 5 (every, or nearly every day), and the severity of each impact varied from 0 (indicating no impact) to 5 (indicating a very severe impact).

Clinical examination and SDF application
After being interviewed, all subjects underwent caries lesions examinations conducted by three trained dentists.Training and calibration exercises were conducted before the study using figures from various clinical scenarios.The inter-examiner reliabilities were measured using Cohen's kappa by examining 10% of the older adults twice in each survey.The kappa values for the inter-and intraexaminer reliability were 0.82e0.88.The oral examinations took place at Bangkok Public Health Center 5 using portable dental chairs.The status of the caries lesion was evaluated using Decayed, Missing due to caries, or Filled Permanent teeth (DMFT) index based on the criteria set by the modified World Health Organization criteria [19].Caries lesions were categorized into two groups: active and inactive caries.Active caries was recorded when the lesion surface could be easily penetrated by a blunt (0.5 mm ball-ended) probe with minimal force.In contrast, inactive (arrested) caries was recorded when the lesion surface felt hard and smooth to the touch.The coding system employed for caries experience and lesion activity in this study was as follows: 0 ¼ sound, 1 ¼ active dentin caries, 2 ¼ arrested dentin caries, 3 ¼ filled, with caries, 4 ¼ filled, without caries, 5 ¼ missing due to caries, 6 ¼ missing for other reasons, and 9 ¼ not recorded.
Subjects who had at least one active caries were requested permission to apply SDF.The SDF treatment was offered to them free of charge throughout the study period.Every patient chose SDF for treatment as an alternative to a complicated filling or extraction.The procedure involved flushing the lesions with water, drying them with compressed air, isolating them with cotton rolls, and then applying 38% SDF (Topamine™ DentaLife, Australia) using the supplied microbrush applicator for a duration of 1e3 min.Following the application, patients were instructed to refrain from eating or rinsing for 30 min, with no other specific restrictions imposed.Patients were encouraged to continue their regular oral hygiene regime, including the use of a fluoridated dentifrice.All subjects were reevaluated after SDF application.

Statistical analysis
All data were analyzed with a statistical program, SPSS (version 28.0).For this study, the level of statistical significance was 5%.Descriptive data were displayed using frequency and percentages.Changes in OIDP scores were determined by the subtracting the pre-treatment score (T0) from the post-treatment score (T1).If the post-treatment score was lower than the pre-treatment score, it indicated a positive change or improvement in Oral Health-Related Quality of Life (OHRQoL).Conversely, if the post-treatment OIDP score was higher than the pre-treatment score, it indicated a negative change or deterioration in OHRQoL.Participants had the possibility of experiencing no change, where the level of impacts on OHRQoL remained unchanged.

Ethical issues
The study was registered in the Thai Clinical Trials Registry (TCTR) under the registration number TCTR20220324002.Ethical approval for the study was obtained from the institute's committee on human research at the Faculty of Dentistry, Chulalongkorn University (HREC_DCU 2020-093).

Results
Table 1 displays the summary of participant characteristics at baseline, including 49 individuals.The group consisted of 23 women and 26 men, with a median age of 64 years (interquartile range: 57e83).All participants had at least one metabolic syndrome, such as hypertension, dyslipidemia, or diabetes.The prevalence of diabetes, hypertension, and dyslipidemia among the participants was 32.7%, 75.5%, and 34.7% respectively.Approximately 42.8% of participants perceived their general health as good or very good, while 26.5% acknowledged having oral problems.In terms of remaining natural teeth, 28.6% had 1-9 teeth, 4.1% had 10-19 teeth, and 2% had 20-28 teeth.Smoking and alcohol consumption were reported by a minority, accounting for 4.1% and 2% of the study population, respectively.

Table 2 illustrates the prevalent causes of Oral
Impacts on Daily Performance (OIDP).Overall, 42.9% of the participants experienced at least one oral impact.The most commonly reported items were "hypersensitivity" and "swollen gums," each reported by 12.2% of the participants.Other prevalent causes included "food impaction," "tooth pain," "tooth abscess," "mobile or inappropriate denture," and "fractured tooth," reported by 6.1%, 4.1%, 4.1%, 2.0%, and 2.0% of the patients, respectively.Table 3 presents the prevalence of OIDP, indicating the percentage of patients reporting at least one oral impact on their daily performance during the previous three months.At baseline, the functional dimension, specifically chewing and enjoying food, had the greatest impact on the patients (18%, n ¼ 9), while no impacts on household activities in the social dimension were reported.Due to COVID-19 situation, this study has some limitations with regard to various follow-up times ranging from 3 to 20 months (averaging 15-month follow-up).The main barriers to follow-up visits during the COVID-19 pandemic were lockdown restrictions, transportation issues, and financial difficulties.At followup, among the 28 interviewed older adults, chewing and enjoying food in the functional dimension still had the greatest impact (16%, n ¼ 8), and no impacts on sleep in the psychological dimension were reported.
Table 4 displays the number and percentage of older adults who experienced positive, negative, or no impacts on their Oral Health-Related Quality of Life (OHRQoL).At the average 15-month follow-up, most older adults showed stable or unchanged OHRQoL.
A total of 19 older adults (13 females and 6 males) received SDF application at baseline, involving 38 teeth and 57 surfaces.The treated teeth included both posterior (68.4%) and anterior (31.6%) teeth, with the majority having proximal lesions (76.3%) and 14 teeth affected on more than one surface (36.8%).All participants had an average follow-up of 15 months (range: 3e20 months), except for three participants who were unable to attend follow-up.During the follow-up examinations, no adverse or unexpected effects of the SDF treatments were observed or reported by the participants.In our study, all of the identified caries involved proximal lesions.91.7% of identified caries were arrested lesions at an average follow-up of 15 months.In terms of patient satisfaction, Fig. 1  participants' feedback regarding pain perception during SDF application.All participants confirmed that the application was generally pain-free, with 66.7% expressing satisfaction and 33.3% having a neutral response.In terms of aesthetic perception after SDF treatment, 53.3% felt satisfied with their aesthetics, 46.7% had a neutral stance, and no patients reported feeling unsatisfied.Regarding the function of teeth after application and the time spent aspect, 53.3% expressed satisfaction and agreed that the SDF application was an easy procedure, while 46.7% had a neutral response.In the overall evaluation by the older adults, the majority (73.3%) found the SDF treatment acceptable in terms of being pain-free, improving aesthetics, enhancing tooth function, and being time-efficient.

Discussion
The study presented data about the existence of oral health problems and negative health impacts on the oral health-related quality of life (OHRQoL) of a representative sample of older adults attending the Primary Health Center in Bangkok.Hypersensitivity and periodontal disease are recognized as major oral health problems due to its high prevalence and negative health impacts if left untreated.Our results contrast with the report from the Ministry of Public Health of Thailand [2], which indicated that the deterioration in quality of life (QoL) due to functional limitations caused by untreated dental caries-related tooth loss would be more pronounced.The presence of periodontal disease, as  c Negative change ¼ OIDP score the follow-up was higher than that of the baseline (negative impact on OHRQoL).observed in this study, is associated with the severity of the condition in both adults and older individuals.Diminished periodontal health can disrupt quality of life through various avenues, encompassing physical aspects, masticatory function, and psychological well-being [18,20,21] This underscores the significance of preventing and promptly addressing periodontal disease, as heightened severity of periodontal damage exerts a more adverse impact on an individual's quality of life.In the current study, the results also show the remarkably high and stable rates of caries arrest after the application of 38% SDF without adverse effects.These findings are the same as several other studies [22,23].
Our results at follow-up indicated that the overall OHRQoL of older adults remained unchanged or stabilized after non-invasive treatment with SDF.This might be because the baseline oral impact on daily performance (OIDP) scores were relatively low.In addition, low OIDP scores could also explain why the majority of untreated tooth decay did not produce dental pain experience before SDF treatment.Similar to a previous study [24], the impacts of dental caries on OHRQoL were low; therefore, the effects or consequences of any treatment may be subtle to detect.In our study, 24% of participants had at least one oral impact affecting their daily activities within the past 3 months; this prevalence of 24% was less than other studies (ranging from 49 to 55%) [18,25e27].This may be because this group of older adults received regular oral healthcare in the Bangkok Public Health Center.
Older adults have shown acceptance regarding the black staining of carious lesions caused by SDF.This acceptance can be attributed to various factors, such as their desire to avoid undergoing restoration procedures during the COVID-19 pandemic, concerns about long waiting times, and fear of associated health risks.Furthermore, the benefits of a quick and non-invasive intervention for caries arrest outweigh the aesthetic outcome for older adults who already contend with the challenges of chronic diseases that significantly impact their daily lives.Therefore, health professionals should consider promoting the use of SDF as a non-invasive and effective treatment option, especially for older adults with carious lesions.
Based on the results regarding changes in the Oral Impacts on Daily Performance (OIDP) score, it was observed that 32.1% of older adults experienced a negative change in their oral health-related quality of life (OHRQoL) during the follow-up period.This could be attributed to the timing of the study, which started in December 2020 before the COVID-19 lockdown and concluded in September 2022 when the pandemic was gradually subsiding.The study focused on older adults in Bangkok, where the epidemic had a significant impact, leading to increased concerns and limited access to oral care.Consequently, their overall quality of life decreased compared to the baseline.
The present study has some limitations with regard to various follow-up times ranging from 3 to 20 months due to COVID-19 situation.The variation in follow-up time may affect the participants' recall bias leading to inaccuracies in their responses.As a result, there may be the regression to the mean phenomenon leading to an overestimation or underestimation of the treatment effect.Furthermore, to isolate the specific impact of SDF on OHRQoL, control group comprising older adults with similar oral problems but without SDF treatment should be established.By implementing these specific recommendations, dental healthcare providers, policymakers, and researchers should work towards improving the oral health outcomes and overall quality of life for older adults, especially those with metabolic syndromes and limited access to dental care.

Conclusion
Due to the existence of oral health problem and negative health impacts, healthcare providers should focus on identifying vulnerable populations and providing targeted interventions to improve oral health outcomes in these groups.Considering the caries arrest outcomes and adverse effects of silver diamine fluoride (SDF) treatment, health professionals should consider promoting the use of SDF as a non-invasive and effective treatment option, especially for older adults with carious lesions.
a Percentage calculation from total number (N ¼ 49).

Table 2 .
Prevalence of specific oral conditions causing an impact on daily performance (n ¼ 49).

Table 4 .
Descriptive statistics for positive, negative, or no changes in the oral impact on daily performance (OIDP) scores for different domains among older adults in Bangkok (n ¼ 28).OIDP score the follow-up was lower than that of the baseline (a positive impact on OHRQoL).
OHRQoL ¼ oral health-related quality of life.a Positive change ¼ b No change ¼ OIDP score of the follow-up was equal to that of the baseline.

Table 3 .
Distribution of oral impact on daily performance (OIDP) scores by dimension among study participants at follow-up (n ¼ 28).Percentage calculation from total number of participants (n ¼ 49).b Follow-up time: Average ¼ 15 months, Range ¼ 3e20 months, varied widely due to Covid-19 pandemic travel restrictions and transportation challenges. a