Effects of self-management interventions based on the COM-B model on peri-implant condition in older adults with periodontitis: a randomized controlled trial

Abstract

Objectives

This study evaluated the impact of self-management interventions based on the COM-B model on peri-implant conditions in older adults with periodontitis.

Materials and methods

The patients were randomly divided into two groups: Group 1 (control group) received only an oral health education (OHE) pamphlet. Group 2 (test group) performed a self-management intervention based on the COM-B model. Each patient was examined for the most inflammatory implant. The measurement parameters included self-efficacy, self-management ability, and clinical indicators such as probing depth (PD), bleeding on probing (BOP), modified gingival index (mGI), modified plaque index (mPI), and peri-implant mucositis severity score (PMSS). The data was collected at baseline, 4, 8, and 12 weeks.

Results

42 patients underwent testing for 3 months. After 12 weeks, the improvement of self-efficacy, self-management ability, and the reduction of BOP, mPI, and PMSS in the test group was significantly higher than in the control group.

Conclusion

The study suggests that self-management interventions based on the COM-B model can enhance the self-management ability of older adults with periodontitis and reduce peri-implant inflammation. This method is more effective than distributing OHE pamphlets.

Trial registration

The randomized controlled clinical trial was registered on Chinese Clinical Trial Registry (No. ChiCTR2400082660, Date: 03/04/2024).

Supplementary Information

The online version contains supplementary material available at 10.1186/s12903-024-05064-1.

Introduction

The digital planting is an effective treatment and has been widely used to repair missing teeth [1]. Periodontitis frequently leads to tooth loss, with the highest prevalence among individuals aged 60 and above [2, 3]. Age and periodontitis are not the limiting factors for dental implants, and it is safe and feasible to place implants after periodontitis is stabilized [4, 5]. Periodontitis is a chronic inflammatory disease caused by the accumulation of dental plaque on the tooth surface, which destroys the periodontal mucosa and eventually causes tooth loss [6]. If dental plaque is not effectively managed, the risk of peri-implant mucositis and implant loss increases [7]. Intervention in patients’ daily oral care behaviour to improve their self-management ability can help control plaque and maintain peri-implant mucosa health [8, 9].

Studies have shown that in addition to dental plaque, smoking, diabetes, diet, depression, income, education level, regular review, and self-care compliance are also factors that affect peri-implant conditions [10–14]. Controlling and managing these risk factors is critical to maintaining peri-implant health, which requires patients to make sustained behavioral changes tailored to their condition [15]. Older adults with periodontitis have poor oral health, and improving patients’ self-efficacy through behaviour intervention can reduce periodontal redness and bleeding [3, 16]. Furthermore, Tan et al. [17] provided the same oral care to periodontitis patients with implants as to periodontally healthy individuals. Both patients achieved equally good results in peri-implant health. This suggests that self-management interventions are necessary for older periodontitis patients with implants, and effective interventions can maintain peri-implant health.

Self-efficacy, first proposed by Bandura [18], refers to a person’s confidence in controlling the development of the disease and achieving the desired outcome through managing their behaviour [19, 20]. The older often lack self-management skills and require significant oral care [21]. The main obstacles to developing self-efficacy in the older include insufficient awareness of preventing oral diseases, unclear understanding of the vital role of self-management in oral care, and low overall health literacy [22, 23]. Implementing personalized behavioral interventions and health education for patients, making them aware of the motivation behind disease management, is essential for improving self-efficacy [24]. The oral health behaviour change is closely related to self-efficacy. Taking intervention measures to improve patients’ self-efficacy based on the health behaviour change model strengthens treatment compliance and increases the frequency of brushing and flossing [25, 26]. However, at present, periodontitis patients with implants have yet to establish a complete intervention method for behaviour change in the maintenance of oral health, and more studies are still needed to supplement relevant content [16]. Considering this, the Capability, Opportunity, Motivation - Behaviour (COM-B) model was selected to intervene in the self-management behaviour of older periodontitis patients with implants to improve their maintenance of implants.

The COM-B model emphasizes the role of the external environment and individual motivation of behaviour change, mainly diagnosing the factors affecting behaviour from three aspects: capability (psychological, physical), opportunity (physical, social), and motivation (reflective, automatic), and linking them with intervention measures to produce the desired behaviour change [27–29]. It is an effective behaviour change model that has received increasing attention in the dental field. However, most studies have only involved changes in patient awareness or oral health behaviour, and have not reflected its impact through clinical indicators [30]. Besides, the field of Periodontology lacks evidence to improve patients’ self-management ability, and there is a need to research applying the COM-B model to enhance patients’ self-efficacy and objectively reflect its influence [31, 32].

This study aimed to evaluate the effect of implementing a self-management intervention based on the COM-B model and compare it with OHE to improve oral self-care in older periodontitis patients with implants, thereby reducing peri-implant inflammation and maintaining a better oral environment.

Materials and methods

Study design

This randomized, single-blind, parallel, controlled trial was conducted at the Department of Stomatology, Affiliated Hospital of Jiangnan University. The project of Jiangnan University affiliated hospital ethics committee approval (certificate number: LS2024040), and registration (registration number: ChiCTR2400082660; registration date: April 3, 2024) on https://www.chictr.org.cn/. All participants in the study provided informed consent. Randomized controlled trials were conducted by the CONSORT flow diagram [33].

Study population

The study included older periodontitis patients with peri-implant mucositis recruited during regular oral maintenance and treatment appointments in the Department of Stomatology at the Affiliated Hospital of Jiangnan University in China. Subjects met the following inclusion criteria: (A) aged 60 years or older with mild to moderate periodontitis; (B) at least one implant remains stable and securely attached;

(C) one or more implant sites had peri-implant mucositis with or without bleeding on probing; (D) radiographs showed no radiological bone loss; (E) at least one implant had visible inflammation, such as no bleeding, slight color change, and slight edema (mGI ≠ 0).

The exclusion criteria are (A) compared to previous radiographs, showed radiographic bone loss in the implant; (B) patients received self-management instruction or oral health education for more than 15 days; (C) the patient has type I and type II diabetes or other systemic severe diseases; (D) use of antibiotics in the three months before baseline; (E) had impairment of cognitive function or physical movement.

Randomization and blinding

After collecting baseline data, a staff member using an excel-based randomization number function. Block randomization with a block size of 4 was adopted. Subjects were assigned 1:1 to the control and test groups randomly. General information questionnaires (GIQ), informed consent forms, and case reports were placed in sealed opaque envelopes. As a result of the data collection, analysis, and behaviour intervention was carried out by a nurse, so the blind method can’t be executed on the nurse. The dentist was unaware of the participants’ group assignments.

Intervention

According to previous literature [10–14, 32, 34], the factors influencing peri-implant health and oral care in the older were identified. Clinical investigation at baseline, GIQ (Appendix S1), self-efficacy scale for self-care (SESS, Appendix S2), self- management ability questionnaire (SMAQ, Appendix S3), PD, BOP, mGI, mPI, and PMSS were collected from subjects. All patients were re-examined at 4, 8, and 12 weeks after intervention, and relevant data were collected.

Patients in the first group received an OHE pamphlet, while those in the second group received self-management interventions based on the COM-B model (Table 1). The interventions include: (1) Teaching the patient to remove plaque at home and checking their oral care method weekly through video calls to correct errors. (2) Keep weekly phone contact with patients and their families to provide support, encourage quitting smoking, and address concerns about treatment costs. (3) Introduce periodontitis and peri-implant mucositis to patients for 30 min per month. (4) Spend 30 min monthly educating patients about the harms of smoking, the importance of follow-up, and the benefits of a healthy diet, and advise them to seek the help of professional smoking cessation personnel. Teach the patient to set phone reminders for reviews and involve family members. Emphasize a low-sugar and low-fat diet. (5) Organize a self-management experience-sharing meeting every month.

Table 1.

Summary of the evidence, intervention function, COM-B, and intervention measures

Evidence	Intervention function	COM-B	Intervention measures
Lack of knowledge about the disease	Education	Capability-Physical	Educate patients about periodontitis and peri-implant mucositis, and emphasize self-care’s importance in removing plaque.
Can not master the method of plaque removal	Education	Capability-Physical	Advocate choosing fluoride toothpaste and an oscillating-rotating electric toothbrush, paying special attention to cleaning the edges, near the edges and mesial areas of the implant, and brushing teeth 3 times a day for 3 min each time. Use an interdental brush or a wooden stick that is suited per interdental area to remove the plaque. Then rinse with an oral irrigator containing 50 ml 0.06% chlorhexidine mouthwash once daily.
Don’t know how to choose food	Restrictions	Capability-Physical	Instruct patients to choose fruits and vegetables rich in vitamins C, D, and B12, adhere to a low-saturated fat diet, and reduce excessive consumption of sugary drinks.
Depression patient has poor oral hygiene	Environmental restructuring	Capability-Psychological	Encourage patients who are feeling depressed to engage in activities that bring them joy.
Lack of self-management confidence	Modelling	Capability-Psychological	Let patients with strong self-management abilities share their experiences and give encouragement to others.
Don’t know how to quit smoking	Persuasion	Opportunity-Physical	It is recommended that patients seek the help of smoking cessation professionals.
Forget review time	Coercion	Opportunity-Physical	Use the phone to schedule a follow-up appointment and inform the patient’s family about the appointment time.
Will not take public transportation	Coercion	Opportunity-Physical	Ask younger family members to accompany the patient to review.
Lack of support	Incentivisation	Opportunity-Social	Let family members and patients learn how to maintain oral health together, family members supervise and guide patients to do a good job of maintaining implants and quitting smoking. Nurses regularly telephone follow-ups.
No feedback on smoking cessation	Enablement	Motivation-Reflective	Encourage patients who struggle to quit smoking, reward those who have successfully quit, and praise non-smoking patients.
Low awareness of smoking cessation and regular review	Training	Motivation-Automatic	The harmful effects of smoking and irregular review on periodontal and implant were explained to the patients, highlighting the benefits of quitting smoking and regular review.
Worried about the cost of treatment	Coercion	Motivation-Automatic	Telling patients that poor oral hygiene will likely cause recurrent peri-implant mucositis may increase treatment costs.

COM-B: Capability, Opportunity, Motivation - Behaviour

Data collection and result definition

Chinese-translated SESS and SMAQ were distributed to each patient at baseline, 4, 8, and 12 weeks to assess self-management ability. At the same time, the implant with the highest score of mucositis in each patient was included as the study object, and the clinical data were obtained by measuring the average values of mesio-buccal, disto-buccal, mesio-lingual, and disto-lingual around the implant. The following parameters were evaluated: (A) SESS: Compiled by Kakudate et al. [35] to evaluate the self-efficacy of patients with periodontitis. There are 15 items, which mainly include three parts: self-efficacy for dentist consultations, self-efficacy in brushing teeth, and self-efficacy in dietary habits. Take per entry a five-point Likert scale from 1 (not confident) to 5 (completely confident), SESS scores ranged from 15 to 75. Moreover, Di Wu et al. [26] translated SESS into Chinese, which has been proven effective, so this study selected it to investigate patients. (B) SMAQ: Compiled by Mengying Li et al. [36], the questionnaire evaluates the self-management ability of Chinese patients with periodontitis. It includes 12 items divided into medical, role, and emotional management. Take per entry a five-point Likert scale from 1 (never) to 5 (very often), scores ranged from 12 to 60. (C) PD: Use a standard probe (the third-generation Florida probe) to measure the distance from the mucosal margin to the sulcus base in mm.(D) BOP: The evaluation criterion was whether there was bleeding within 30 S after probing.

(E) mGI: It was put forward by Loe et al. [37] to evaluate the condition of the soft tissue surrounding the implant (Table 2). (F) mPI: It was raised by Mombelli et al. [38] to evaluate plaque accumulation (Table 2). (G) PMSS: A surrogate variable (0–16 score) proposed by Grischke et al. [39] was used to assess the severity of peri-implant mucositis (Table 3). It is derived from the accumulation of mGI scores (0–3 points) and BOP scores (1 point if there is bleeding) of the four parts of the implant, with the highest score being mGI 12 points and BOP 4 points.

Table 2.

Scores of soft tissue status and plaque accumulation around the implant

Score	mGI is used to assess the status of mucous around oral implants [37]	mPI is used to evaluate plaque accumulation around oral implants [38]
0	No bleeding, normal gingiva	No detection of plaque
1	No bleeding, slight color change, slight edema	Plaque is only recognized by running a probe across the smooth marginal surface of the implant
2	Bleeding on probing, redness, edema, and glazing	The plaque can be identified with the naked eye
3	Spontaneous bleeding, marked redness, edema, and ulceration	Abundance of soft matter

mGI: modified gingival index, mPI: modified plaque index

Table 3.

Definition of the PMSS [39, 40]

score	definition
0	No inflammation
1–4	Mild inflammation
5–12	Moderate inflammation
13–16	Severe inflammation

PMSS: peri-implant mucositis severity score

The inspector (YN C) underwent standardized data measurement and collection training from an experienced periodontist (FY Z) (a senior dentist with > 10 years of clinical experience), possible areas of dispute were discussed. Prior to the research, 6 subjects not included in the study were randomly selected for repeated measurements by YN C and FY Z. Measurement error was tiny, with all Kappa values > 0.75. In addition, YN C carried out all experimental data measurement and collection, so the data acquisition could be considered standardized.

Statistical analysis and sample size calculation

Statistical Package for Social Science (SPSS, Version 26.0) was used for statistical analysis. To compare the characteristics of the control group and the test group at baseline, the independent-sample t-tests and the χ² tests were performed to assess the difference in the mean ± standard deviation (SD) of the continuous variables and the distribution of categorical variables between groups, respectively. The Shapiro-Wilk test confirms the normal distribution of continuous variables.

We used one-way ANOVA for within-group comparisons and evaluated parameter changes at baseline, weeks 4, 8, and 12. The optimal covariance structure (scale identity) was determined by using a mixed linear model for between-group comparison, with time as the covariate. With the aid of a mixed linear model to assess the differences between the intervention measures for various parameters, and reflect the effect of time on the differences in parameters. Furthermore, the interaction was used to test whether the intervention and time matching affected the occurrence of differences in parameters. The significance level for all tests was established at 0.05.

The sample size was estimated by G*Power (version 3.1.9.4), with an analysis [95% power (Cohen’s d = 0.5); 5% significance level; F tests - ANOVA: Repeated measures, within-between factors], 36 subjects were obtained. Considering the 20% lost follow-up rate, 44 subjects were finally included, 22 in the control group and 22 in the test group. Due to the absence of follow-up, 20 people in the control group and 22 people in the test group completed the study.

Results

65 patients were assessed for eligibility, 44 of whom were randomized to receive the intervention, as shown in the CONSORT flow diagram (Fig. 1). Since the control group lost one person at 8 weeks and one at 12 weeks, 42 subjects completed the study, 20 in the control group and 22 in the test group. At baseline, there were no significant socio-demographic /behavioral differences between the two groups, and no significant differences in other measurement parameters were observed, as shown in Table 4. During the study, no adverse events occurred in either group.

Fig. 1.

CONSORT flow diagram of participants in recruitment

Table 4.

Socio-demographic backgrounds, behavioral, and clinical parameters at baseline in the control and test groups

Parameter	Control group(n = 20)	Test Group (n = 22)	Total(n = 42)	p-value
Age (years, mean ± SD)	64.5 ± 3.6	64.8 ± 3.6	64.6 ± 3.5	0.74
Gender (%)
Female	10(50)	10(45.5)	20	0.77
Male	10(50)	12(54.5)	22
Education Level (%)
Up to junior high school	5(25)	6(27.3)	11	0.96
Senior high school	9(45)	9(40.9)	18
Tertiary education	6(30)	7(31.8)	13
Family monthly income (%)
≤ 5000 RMB	6(30)	6(27.3)	12	0.91
5000–10,000 RMB	8(40)	8(36.4)	16
≥ 10,000 RMB	6(30)	8(36.4)	14
Severity of periodontal disease (%)
Mild	8(40)	8(36.4)	16	0.81
Moderate	12(60)	14(63.6)	26
Position of implants (%)
Anterior	11(55)	13(59.1)	24	0.79
Posterior	9(45)	9(40.9)	18
Brushing frequency (%)
Once a day	13(65)	16(72.7)	29	0.59
Twice or more times a day	7(35)	6(27.3)	13
The state of smoking (%)
Current smoker	6(30)	6(27.3)	12	0.91
Former smoker	6(30)	8(36.4)	14
Never smoker	8(40)	8(36.4)	16
SESS (mean ± SD)	37.4 ± 4.0	35.2 ± 4.2	36.3 ± 4.2	0.09
SMAQ (mean ± SD)	26.4 ± 3.8	25.1 ± 3.3	25.7 ± 3.6	0.26
Clinical findings (mean ± SD)
PD	2.1 ± 0.5	2.0 ± 0.5	2.0 ± 0.5	0.51
BOP	0.5 ± 0.3	0.5 ± 0.2	0.5 ± 0.2	0.86
mGI	1.1 ± 0.8	1.4 ± 0.6	1.3 ± 0.7	0.2
mPI	1.1 ± 0.4	0.9 ± 0.4	1.0 ± 0.4	0.2
PMSS	6.6 ± 3.9	7.6 ± 3.2	7.1 ± 3.5	0.33

SD: standard deviation, SESS: self-efficacy scale for self-care, SMAQ: self-­management ability questionnaire, PD: probing depth, BOP: bleeding on probing, mGI: modified gingival index, mPI: modified plaque index, PMSS: peri-implant mucositis severity score

Although the measured parameters did not differ significantly between the two groups at baseline, the participants had specific characteristics. The average age of the participants was 65 years old, at a time when learning and self-care were perfectly sane. Secondly, more than 70% of the participants have an education level of high school or above and an income level of 5,000 RMB or above, which is higher than the average for older adults in China. In addition, more than 60% of the participants had moderate periodontitis, and less than 30% currently smoked, which could impact peri-implant health. Regarding SESS (P = 0.09) and SMAQ (P = 0.26), there were small but insignificant differences between groups, with the control group slightly higher. In terms of clinical indicators, the PMSS was 6.6 (SD = 3.9) in the control group and 7.6 (SD = 3.2) in the test group. Patients in both groups were moderate inflammation and had no significant differences in PD (P = 0.51), BOP (P = 0.86), mGI (P = 0.2), and mPI (P = 0.2).

Compared with baseline, both groups showed significant improvement in SESS and SMAQ after 12 weeks of follow-up (Table 5). SESS in the control group increased progressively after monthly OHE (baseline: 37.4; 4 Weeks: 38.7; 8 weeks: 40.1; 12 weeks: 41.2), with significant differences from baseline to 8 weeks and 12 weeks. SESS also showed an increasing trend after self-management intervention (baseline: 35.2; 4 Week: 38.8; 8 week: 41.7; 12 week: 47.2), with significant differences from baseline at all other time points. There were significant differences in the main effects of group and time as well as the interaction between group and time (p < 0.05), indicating different intervention effects for the two groups. The SESS of the test group was higher after 12 weeks and continued to improve over time. The combination of group and time had an impact on SESS.

Table 5.

Comparing changes in parameters at different times and among different groups

	Parameter	baseline	4 Week	8 Week	12 Week	p-value
						Group	Time	Group*Time
Control group	SESS	37.4 ± 4.0	38.7 ± 3.4	40.1 ± 3.4 a	41.2 ± 4.0 ab	<0.05*	<0.001***	<0.001***
Test group		35.2 ± 4.2	38.8 ± 3.6 a	41.7 ± 3.6 ab	47.2 ± 3.0 abc
Control group	SMAQ	26.4 ± 3.8	28.7 ± 3.1	30.4 ± 4.1a	31.5 ± 4.7ab	<0.05*	<0.001***	<0.05*
Test group		25.1 ± 3.3	30.0 ± 3.7 a	33.4 ± 3.9 ab	36.0 ± 3.7 abc
Control group	PD	2.1 ± 0.5	2.2 ± 0.4	2.3 ± 0.4	2.3 ± 0.4	0.385	<0.05*	0.987
Test group		2.0 ± 0.5	2.1 ± 0.5	2.2 ± 0.5	2.3 ± 0.5a
Control group	BOP	0.5 ± 0.3	0.7 ± 0.3	0.8 ± 0.2 a	0.9 ± 0.2 ab	<0.001***	<0.05*	<0.05*
Test group		0.5 ± 0.2	0.5 ± 0.2	0.5 ± 0.2	0.6 ± 0.2
Control group	mGI	1.1 ± 0.8	1.4 ± 0.7	1.8 ± 1.0 a	2.0 ± 1.1 ab	0.065	0.238	<0.05*
Test group		1.4 ± 0.6	1.4 ± 0.6	1.4 ± 0.8	1.1 ± 0.9
Control group	mPI	1.1 ± 0.4	1.3 ± 0.4	1.3 ± 0.5	1.2 ± 0.6	<0.001***	0.155	0.058
Test group		0.9 ± 0.4	0.9 ± 0.4	0.7 ± 0.3	0.5 ± 0.3 ab
Control group	PMSS	6.6 ± 3.9	8.2 ± 3.5	10.3 ± 4.0 a	11.4 ± 4.8 ab	<0.05*	0.076	<0.001***
Test group		7.6 ± 3.2	7.8 ± 3.0	7.5 ± 3.0	6.1 ± 2.8

SESS: self-efficacy scale for self-care, SMAQ: self-­management ability questionnaire, PD: probing depth, BOP: bleeding on probing, mGI: modified gingival index, mPI: modified plaque index, PMSS: peri-implant mucositis severity score. ^a Indicates a statistically significant difference from the baseline. ^b Indicates a statistically significant difference compared with 4 weeks

^C Indicates a statistically significant difference compared to 8 weeks. *Significant difference (P < 0.05), ***Significant difference (P < 0.001)

SMAQ also showed similar results to SESS. SMAQ continued to improve in the control group (baseline: 26.4; 4 weeks: 28.7; 8 weeks: 30.4; 12 weeks: 31.5), and there was a significant difference between the 8-week and 12-week compared to baseline. The scores of the test group in other periods were higher than the baseline, and there were significant differences (baseline: 25.1; 4 Week: 30.0; 8 week: 33.4; 12 week: 36.0). There were significant differences in the main effects of group and time as well as the interaction between group and time (p < 0.05), indicating that the intervention effect of test group was better than that of control group, and the self-management ability of patients could be strengthened over time. The combined effect of time and interventions could affect the self-management ability of patients.

PD did not improve throughout the study. There were slight changes in PD in both groups. The PD of the control group increased from 2.1 at baseline to 2.2 at 4 weeks, and stabilized at 2.3 at 8 weeks and 12 weeks, with no difference in different periods. PD in the test group differed from baseline and 12 weeks (baseline: 2.0; 4 Weeks: 2.1; 8 weeks: 2.2; 12 weeks: 2.3). Despite there was no significant difference between groups in the main effect of the intervention and the interaction between group and time, time could significantly affect the change of PD (p < 0.05).

BOP severity increased in the control group (baseline: 0.5; 4 weeks: 0.7; 8 weeks: 0.8; 12 weeks: 0.9), with significant differences from baseline at 8 and 12 weeks. The BOP of the test group tended to be stable at baseline, 4 and 8 weeks at 0.5, and rose to 0.6 at 12 weeks, with no significant difference in each period. The analysis showed significant differences in the main effects of group and time and the interaction between group and time (p < 0.05), suggesting that the test group experienced a reduction in BOP severity. BOP worsened over time, and the combined impact of group and time varied.

mGI not only did not improve but was more severe in the control group (baseline: 1.1; 4 Weeks: 1.4; 8 weeks: 1.8; 12 weeks: 2.0), where 8 weeks and 12 weeks were significantly different from baseline. On the contrary, mGI in the test group stabilized at 1.4 from baseline to 8 weeks, and decreased to 1.1 after 12 weeks, with no significant difference at each time point. Although the main effect of group and time showed no difference, the interaction between group and time was different (p < 0.05), warranting further investigation.

mPI did not differ significantly across periods in the control group, with a baseline of 1.1 and a decrease to 1.2 at 12 weeks after maintaining a level of 1.3 at 4 and 8 weeks. The baseline and 4-week values of the test group remained at 0.9 and then continued to decline (0.7 at 8 weeks; 0.5 at 12 weeks), showing a significant difference from baseline to 12 weeks. The two groups had a significant difference (p < 0.05). The test group was more effective at removing plaque, and there was no significant difference in the main effect of time or the interaction between the group and time.

PMSS increased gradually in the control group (baseline: 6.6; 4 weeks: 8.2; 8 weeks: 10.3; 12 weeks: 11.4), with significant differences from baseline to 8 weeks and 12 weeks. The test group showed no significant difference at each time point, with values increasing from baseline 7.6 to 4 weeks 7.8 and then decreasing (8 weeks: 7.5; 12 weeks: 6.1). There were significant differences in the main effect and interaction between groups and time (p < 0.05). The test group was better at reducing peri-implant mucositis than the control group, and the control group experienced increasingly severe peri-implant mucositis over time. The main effect of time did not reveal any difference.

Discussion

This study aimed to assess the effect of delivering an OHE pamphlet or implementing a self-management intervention based on the COM-B model in reducing peri-implant inflammation in older adults with periodontitis over 12 weeks. The present findings suggest that self-management interventions based on the COM-B model not only improve patients’ self-efficacy and self-management ability, but also further reduce the severity of BOP, mPI, and PMSS compared to OHE. Therefore, an intervention for self-management based on the COM-B model is suitable for maintaining peri-implant health in older adults with periodontitis.

At baseline, although there were no significant differences in general information and measurement parameters between the control and test groups, all participants had specific characteristics. To more easily identify the impact of different interventions on the experiment, most of the participants selected in this study had moderate periodontitis and peri-implant mucositis. Which could more intuitively observe the improvement effect of different interventions on peri-implant inflammation. Moreover, the participants were recruited from more developed cities in China, so they were generally young older adults with higher education and income than the average older Chinese. Studies have shown that people with higher levels of education and income attach more importance to oral health and hold a positive attitude towards behaviour that promote oral health [22, 23]. Therefore, these characteristics of the participants provide sufficient conditions for this study’s development.

After 12 weeks, there were significant differences in SESS, SMAQ, BOP, mPI, and PMSS between the two groups (p < 0.05), but no significant differences in PD and mGI. The 12-week intensive intervention led to significantly higher self-efficacy and self-management in the test group compared to the control group. This is similar to the studies of Bandura [20] and Kakudate [41] et al. The improvement of self-efficacy will cause modifications in patients’ behaviour and ultimately bolster patients’ self-management capability. Lack of disease-related information and motivation to obey treatment are the main factors affecting the improvement of self-efficacy in patients with periodontitis and peri-implant mucositis [42]. The self-management intervention based on the COM-B model addressed patients’ lack of information and motivation by explaining the disease and promoting daily oral cleaning. Therefore, the test group could improve patients’ self-efficacy and self-management ability better than the control group, which only distributed OHE pamphlets.

Although self-efficacy and self-management ability improved in both groups, the BOP of the control group increased from 0.5 to 0.9, possibly because the improvement of self-management ability did not significantly change oral cleaning behaviour. While the improvement of the self-management ability of the test group was more obvious than that of the control group, the BOP of the test group was stable at 0.5–0.6, and did not alleviate. Bunk et al. [40] pointed out that bleeding during examination does not necessarily mean the intervention is ineffective, as it may take a long time for peri-implant mucositis to go into remission. Some patients still show signs of bleeding after 3 to 12 months [43]. BOP is an influential factor in the PMSS. After 12 weeks of intervention, patients in both groups still had moderate inflammation, but the control group tended to develop severe inflammation. In contrast, the test group tended to develop mild inflammation. This may be because the intervention time is too short to make a significant difference between groups.

Improving self-management abilities has a positive impact on reducing mPI. The intervention based on the COM-B model reduced mPI from 0.9 to 0.5 in the test group by instructing patients on properly removing dental plaque. Through weekly contact with the patient to correct the wrong removal steps, while urging the patient to adhere to a plaque-reduction lifestyle, such as smoking cessation and a healthy diet. The control group also basically mastered removing dental plaque through the OHE, but the usual wrong steps were not corrected in time. Hence, mPI in the control group was stable between 1.1 and 1.3 and did not show effective reduction. This is consistent with the findings of Shen et al. [44], Almabadi et al. [45] and Lin et al. [46] that personalized oral health intervention can improve the self-management ability and reduce the plaque index of patients with periodontitis more than handling out OHE pamphlets.

The recent 11th European Workshop on Periodontology proposed that psychological methods to change patients’ oral health behaviour can reduce dental plaque and prevent periodontal and peri-implant inflammation [15, 47]. Other evidence also manifests that psychology-based health behavior change theories can improve oral health in patients with periodontitis compared to non-theoretical approaches [48, 49]. Encouraging patients to take charge of their oral health through personalized education to prevent periodontal diseases is crucial [24]. Thus, we chose the COM-B model as the theoretical framework to change patients’ oral self-management behaviour.

COM-B model was first proposed by Michie et al. [50] and is the only theoretical model that adopts corresponding behaviour change strategies based on factors that affect behaviour [27, 28]. Other traditional behavior change models include the knowledge-attitude-practice model and information-motivation-behaviour model, which emphasize the influence of individual cognition and motivation on behaviour change while ignoring the influence of non-cognitive determinants such as environment and society [30]. The COM-B model summarizes the factors affecting patient behavior into capacity, opportunity, and motivation. It develops personalized intervention measures according to the individual and the external environment, addressing the shortcomings of current behaviour change theory [51]. However, currently, the COM-B model is rarely used in patients with periodontal disease. Chang et al. [52] utilized the COM-B model to build a mobile application to improve patients’ ability to perform oral self-care. However, the reliability of the program was not reflected through clinical indicators. This study makes up for the shortcomings of the experiment and expands the application of the COM-B model in the field of periodontitis.

Maintaining long-term oral health after a dental implant relies on regular review and daily oral hygiene [53]. It is necessary to improve the oral self-management ability of older adults with poor self-care [54]. It is worth emphasizing that this study adopts the health behaviour change theory of psychology to construct a scientific intervention plan. Which provides more reference for the oral self-management of periodontitis and dental implants. Further, we chose the older adults with the highest prevalence of periodontitis as the study objects. In the study, subjects had similar education and economic levels to avoid their impact on the test results. Compared to other studies, the self-management intervention based on the COM-B model excels in individualization. This can solve problems in the intervention process and provide timely and objective feedback using questionnaires and clinical indicators. We not only focused on the impact of plaque on patients but also interventions for smoking, diet, depression, income, education, regular review, and self-care. The periodontists spend less time on these aspects, while nurses’ involvement saves them time and effort and reduces other factors affecting peri-implant health [55].

However, there are some limitations to this study. Most periodontitis patients have received varying degrees of oral health instruction. But we do not do a good job of making oral self-care the same for all patients before intervention. Other studies have indicated that patients with dental implants for periodontitis show higher treatment compliance compared to healthy individuals [56]. These factors might impact the intervention outcome. Individuals with lower education and economic status experienced poorer oral health [57, 58]. This group represented only a tiny portion of the study. So, it remains to be confirmed whether self-management intervention based on the COM-B model can be widely used. Secondly, the ability to self-manage will diminish over time. Therefore, it is essential for the intervenor to consistently establish effective communication with the participants to strengthen their self-management ability. The current study has a small sample size and a short intervening time. At a later stage, a larger sample size and longer intervention time will be necessary to assess the effectiveness of this intervention more accurately. Finally, most people were unwilling to pay extra for dental care, and the intervention services for this study were free [47, 59]. There are potential obstacles to the large-scale and long-term application of self-management interventions based on the COM-B model, such as the lack of compensation for the interveners and the inability of people with lower socioeconomic status to afford the relevant medical expenses.

Conclusion

Self-management intervention based on the COM-B model can improve the self-management ability of older adults with periodontitis and decrease peri-implant inflammation. This method works better than regular distribution of OHE pamphlets.

Electronic supplementary material

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Abbreviations

COM-B

Capability, Opportunity, Motivation - Behaviour model

OHE

an oral health education

PD

probing depth

BOP

bleeding on probing

mGI

modified gingival index

mPI

modified plaque index

PMSS

peri-implant mucositis severity score

GIQ

general information questionnaires

SESS

self-efficacy scale for self-care

SMAQ

self­ management ability questionnaire

SPSS

Statistical Package for Social Science

SD

standard deviation

Author contributions

MC H: wrote the main manuscript text; LP Y: data collect and revising manuscript; YN C: data collection, data analysis and preparation of the paper; Z D: concept and design of the study; H M: project management and implementation; YF G: literature and revised the manuscript; FY Z: design of the work, training and calibrating dental examiners, and substantively revised the manuscript. All persons named as authors warrant that they have reviewed and approved the manuscript prior to submission.

Funding

This work was supported by the Healthentalent plan of Taihu Lake in Wuxi (Double Hundred Medical Youth Professionals Program) from Health Committee of Wuxi (No.HB2023054). General Project of Wuxi Municipal Commission of Health and Family Planning (No.M202240). Clinical Research and Translational Medicine Research Program, Affiliated Hospital of Jiangnan University (No.LCYJ202223)(No.LCYJ202346).The funding bodies were not involved in the design of the study, data collection, analysis, or interpretation of the data and writing the manuscript.

Data availability

The datasets generated and analyzed during the current study are available from the corresponding author on reasonable request.

Declarations

Ethics approval and consent to participate

Ethical approval was obtained from the Medical Ethics Committee, Affiliated Hospital of Jiangnan University (certificate number: LS2024040), and registration on Chinese Clinical Trial Registry (registration number: ChiCTR2400082660; registration date: April 3, 2024). All participants in the study provided informed consent.

Consent for publication

Not applicable.

Competing interests

The authors declare no competing interests.