Periodontal Health Status, Awareness, and Oral Hygiene Practices among Fixed and Removable Partial Denture Wearers in Al-Ahsa, Saudi Arabia

ABSTRACT

Aim:

Partial dentures, whether fixed or removable, play a crucial role in restoring oral function and aesthetics in patients with partial edentulism. However, inadequate hygiene practices around these prostheses may lead to periodontal complications This study aimed to evaluate periodontal health status, oral hygiene practices, and awareness among fixed and removable partial denture wearers in Al-Ahsa, Saudi Arabia.

Methods:

A cross-sectional clinical study was conducted among 298 adult patients attending the dental clinics of King Faisal University. Clinical assessments included the plaque index, gingival index, and calculus surface index. Participants also completed a structured questionnaire assessing demographics, hygiene behaviors, prosthesis type, and awareness. Statistical analyses were performed using univariate and multivariable logistic regression to determine associations between hygiene practices and periodontal indices.

Results:

Among 298 participants, a high prevalence of suboptimal periodontal health was observed, with only 24.8%, 27.2%, and 36.2% scoring zero (healthy) on the plaque, gingival, and calculus indices, respectively. Multivariable analysis revealed that regular prosthesis cleaning was a significant protective factor against high plaque (adjusted odds ratio [AOR] = 0.51, P value = 0.032) and gingival indices (AOR = 0.54, P value = 0.024). Conversely, removable partial dentures were a significant independent risk factor for a high calculus index (AOR = 2.08, P value = 0.030) compared to fixed prostheses. Furthermore, a significant knowledge-practice gap was identified; while 71.5% believed prostheses need special care, 44.0% admitted to not cleaning theirs regularly.

Conclusion:

This study concludes that regular prosthesis cleaning and frequent tooth brushing are strongly associated with reduced risks of plaque accumulation and gingival inflammation. In contrast, the use of a removable partial denture is independently associated with a significantly higher risk of calculus formation. These findings highlight that while behavioral interventions are crucial for managing soft tissue health, the prosthesis type itself is a key determinant of hard deposit accumulation.

INTRODUCTION

Prosthodontics is the branch of dentistry focused on replacing missing or damaged teeth with artificial substitutes such as crowns, bridges, and dentures.[1] Partial dentures, whether fixed (e.g., crown-bridge work) or removable appliances, restore esthetics, and masticatory function for partially edentulous patients. However, these restorations can adversely affect the adjacent periodontal tissues if proper oral hygiene is not maintained.[2] The junction between a dental prosthesis and the natural tooth surface often creates plaque-retentive areas where bacteria can accumulate, leading to gingival inflammation, periodontal pocketing, or caries on abutment teeth.[3,4] For instance, subgingival crown margins have been associated with increased plaque deposits and deeper probing depths in the surrounding gingiva.[5,6] Likewise, removable partial dentures (RPDs) with ill-fitting clasps or improper design may trap food and plaque, contributing to localized periodontitis if not managed carefully.[7,8]

Long-term clinical studies have explored the relationship between partial dentures and periodontal health. Many have found that RPD wearers exhibit higher plaque and gingival index (GI) scores, especially around abutment teeth, compared to individuals without RPDs.[7,9] Jespen et al. reported that RPD use was significantly associated with increased gingivitis and attachment loss at abutment sites over time.[2,10] Similarly, abutment teeth supporting fixed partial dentures (FPDs) can be more prone to periodontal inflammation than non-abutment teeth.[11] Al-Sinaidi and Preethanath[3] observed that in patients with FPDs, gingival indices, and bleeding on probing were worse around crowned abutments relative to adjacent uncrowned teeth.[11] These findings highlight that the design and presence of a prosthesis can alter the local oral environment, emphasizing the importance of meticulous hygiene and regular periodontal monitoring in these patients.

Despite the known risks, partial dentures remain indispensable in rehabilitating partial edentulism. In Saudi Arabia, as in many countries, partial edentulism is common among adults, and the use of fixed or removable prostheses is prevalent for replacing missing teeth.[12] However, there may be gaps in patient knowledge and oral hygiene practices related to these prostheses. International studies have demonstrated that many patients lack adequate instruction on denture hygiene maintenance.[13] For example, a survey in Wales found that although 91.8% of RPD wearers reported receiving hygiene instructions, over 60% still had poor denture cleanliness on examination.[14,15] Another audit by Mylonas et al. revealed deficient knowledge among partial denture patients, with many unaware of optimal cleaning methods and some even wearing their dentures 24 h a day.[9] Locally, anecdotal evidence and limited studies suggest similar trends: patients may not be fully aware of the need for special care of prosthetic appliances, and compliance with cleaning recommendations is often low. Indeed, earlier Saudi studies have reported low usage of interdental cleaning aids (with dental floss usage ranging from only ~5% up to 39% in various populations),[11] indicating potential challenges in maintaining plaque control around complex restorations.

RATIONALE

Given the potential impact of partial dentures on periodontal health and the apparent deficiencies in patient awareness, this study was conducted to evaluate the current status in a sample of partial denture wearers in Al-Ahsa. We aimed to quantitatively assess periodontal health indices in this group and correlate them with patients’ oral hygiene practices and knowledge levels. We also sought to identify common complications or complaints associated with partial dentures, as understanding these can inform patient education and preventive strategies. By focusing on Al-Ahsa, a systematic search of PubMed, Embase, and Google Scholar databases conducted before initiating this study yielded no similar published studies specifically addressing periodontal health status and hygiene practices among partial denture wearers in this region, highlighting the gap in regional research. Most prior studies in the Kingdom have focused on other areas (such as Aseer[1] or Riyadh[16]) or on general oral health attitudes rather than the prosthesis-related periodontal outcomes.[17]

OBJECTIVES

The primary objective of this study was to assess the periodontal health status of fixed and RPD wearers using standard indices and to evaluate their oral hygiene practices and awareness regarding prosthesis care. We hypothesized that a significant proportion of partial denture patients would exhibit signs of plaque-induced gingival inflammation and that suboptimal hygiene practices (e.g., infrequent cleaning and lack of floss use) would be associated with worse periodontal indices. A secondary objective was to determine the level of patient awareness about the maintenance needs of their prostheses. For example, whether they know that dentures require special cleaning or that they should avoid continuous wear. By clearly defining these objectives, the study aims to generate data that can guide interventions (such as targeted oral hygiene instructions or recall programs) to improve the periodontal outcomes and overall oral health-related quality of life for this patient group.

MATERIALS AND METHODS

STUDY DESIGN AND SETTING

This research was conducted as a cross-sectional clinical study at the Dental Clinic Complex of King Faisal University (KFU) in Al-Ahsa, Saudi Arabia. The study aimed to assess periodontal health, oral hygiene practices, and awareness among patients wearing fixed or RPDs. Ethical approval was obtained from the institutional review board of KFU with reference number KFU-REC-2024-MAR-ETHICS2152. All procedures were conducted in accordance with the Declaration of Helsinki. Informed consent was obtained from each participant before enrollment. The data collection took place over a 7-month period in 2024. The study followed the Strengthening the Reporting of Observational Studies in Epidemiology guidelines for cross-sectional research.[18,19] Two calibrated dental professionals (a prosthodontist and a periodontist) performed the clinical examinations. The questionnaire and clinical indices used were adapted from previously validated tools in similar epidemiological studies.

STUDY POPULATION AND SAMPLING

The study population comprised adult patients attending the Dental Clinic Complex at KFU in Al-Ahsa, Saudi Arabia. Participants were recruited from eligible and willing individuals presenting to the prosthodontic and periodontic outpatient units during the study period. Eligibility criteria required patients to be between 25 and 60 years of age and to be current users of either fixed or removable partial dental prostheses. All individuals provided written informed consent after receiving detailed information about the study’s objectives and procedures.

Patients were excluded if they had received periodontal therapy or systemic antibiotic treatment within the preceding 3 months, to minimize the influence of recent interventions on periodontal indices. Individuals with systemic conditions that could significantly influence periodontal health, except for those with well-controlled diabetes mellitus, were also excluded from the study. Women who were pregnant or lactating were not included due to hormonal influences on periodontal tissues. In addition, those without a prosthesis at the time of clinical evaluation were excluded to ensure the study population reflected current prosthesis users.

A total of 298 patients fulfilled the inclusion criteria and were included in the final analysis. With this sample size the study had 80% statistical power to detect meaningful differences in periodontal status across relevant demographic and behavioral subgroups.

CLINICAL EXAMINATION

Each participant underwent a comprehensive clinical oral examination conducted by two calibrated dental professionals. To ensure inter-examiner reliability for plaque, gingival, and calculus assessments, calibration exercises were performed before data collection using Cohen’s kappa statistic (K = 0.83, 95% confidence intervals [CIs]: 0.81–0.93), which revealed significant agreement between these examiners. The clinical assessment focused on evaluating periodontal status using three standardized indices: the plaque index (PI), the GI, and the calculus surface index (CSI). These were selected for their established validity and reproducibility in epidemiological studies.

The PI, based on the criteria described by Silness and Löe,[17] was used to measure the thickness of plaque on the gingival third of the tooth surface. Scores ranged from Grade 0, indicating no visible plaque, to Grade 3, reflecting heavy plaque accumulation along the gingival margin and in the interdental spaces. The index was recorded on four surfaces of each tooth (buccal, lingual, mesial, and distal) and summarized per patient.

The GI, also following the Löe and Silness[17] scoring system, assessed the severity of gingival inflammation. Grade 0 represented clinically healthy gingiva, while Grade 1 denoted mild inflammation without bleeding. Grades 2 and 3 indicated moderate and severe inflammation, respectively, the latter often accompanied by spontaneous bleeding on probing. Examination was performed using a periodontal probe with light pressure to minimize tissue trauma and ensure consistent grading.

To evaluate calculus accumulation, the CSI described by Ennever et al.[18] was applied.[8] This index classified supragingival and subgingival calculus based on the proportion of the tooth surface covered. Grade 0 denoted an absence of calculus; Grade 1 indicated supragingival calculus covering up to one-third of the exposed surface; Grade 2 covered more than one-third but less than two-thirds, and Grade 3 represented extensive deposition exceeding two-thirds or the presence of dense subgingival calculus bands.

This assessment focused on the abutment teeth supporting the prostheses, given their susceptibility to localized plaque accumulation and inflammation. However, scores were also recorded for adjacent and non-abutment teeth to allow for comparative analysis. All examinations were carried out under standardized lighting conditions using a dental mirror, explorer, and World Health Organization periodontal probe. Before GI scoring, plaque was removed and disclosing agents rinsed to avoid artifactual inflammation readings. The highest observed score per index was documented for each participant.

QUESTIONNAIRE

Participants completed a structured interviewer-administered questionnaire designed to collect data on demographic characteristics, prosthesis type and duration, oral hygiene habits, knowledge, and awareness of prosthesis care, and self-reported complications. The questionnaire contained 18 varying items. Responses were recorded using closed ended yes/no and multiple-choice formats. Except demographic questions, tool reliability was tested through Cronbach α, which was found to be 0.758; this confirmed that tool was reliable. The full questionnaire content is provided in Appendix A.

STATISTICAL ANALYSIS

Categorical variables, such as demographic, prosthesis characteristics, and oral hygiene habits, were summarized using frequencies and percentages. The responses of knowledge and awareness items were reported.

For logistic regression analysis, four-point values of plaque gingival and calculus indices were converted into two categories, Grade 0 and 1 marked as low index and Grade 2 and Grade 3 marked as high index. Initial associations between each independent variable and the dichotomized oral health indices (high vs. low PI, high vs. low GI, and high vs. low calculus index) were assessed using univariate logistic regression. Results were expressed as crude odds ratios with their corresponding 95% CIs. All independent variables that demonstrated a statistically significant association (P value ≤ 0.05) in the univariate analysis for a given outcome were selected as candidates for inclusion in the respective multivariable model.

Multivariable logistic regression models were constructed for each of the three outcomes (PI, GI, and calculus index) to identify independent predictors while controlling for potential confounders. The models were built including all significant variables from univariate screening. The results of these models are presented as adjusted odds ratios (AOR) with 95% CIs.

RESULTS

DEMOGRAPHIC, PROSTHESIS CHARACTERISTICS, AND ORAL HYGIENE PRACTICES

This study analyzed a sample of 298 individuals with dental prostheses. The demographic profile revealed a sample with a predominance of male participants (61.4%) and a relatively young age distribution, with the largest subgroup being individuals aged 20–30 years (43.6%). A substantial majority of the participants (76.2%) reported no systemic chronic diseases.

Regarding prosthetic characteristics, FPDs were the most prevalent type of restoration, accounting for 65.4% of cases, followed by RPDs (27.2%). In terms of prosthesis longevity, the duration of use was varied: while 31.2% had been using their prosthesis for less than 1 year, a combined 68.8% had worn their prosthesis for 1 year or longer, indicating substantial experience with prosthetic maintenance among most participants.

Oral hygiene practices demonstrated both positive trends and areas for concern. A slight majority of participants (56.0%) reported regular cleaning of their prosthesis. Toothbrushing was the overwhelmingly dominant cleaning method (84.6%), while the use of miswak (7.7%), mouthwash (6.0%), and dental floss (1.7%) was considerably less common. Most participants maintained a daily brushing frequency of either once (43.0%) or twice (48.7%) daily.

The analysis of dental visitation patterns revealed noteworthy findings. Although 63.4% of participants indicated they attended some form of dental checkup, a detailed examination of visitation intervals showed that 36.6% reported no routine dental visits whatsoever representing the single largest visitation category. Among those who did seek periodic care, the most common schedules were six-monthly (28.2%) or annual (26.8%) intervals. This pattern was further reflected in participants’ self-assessment, as half of the respondents (50.3%) explicitly stated they did not attend regular dental visits, highlighting a significant gap in consistent professional oral healthcare within the cohort [Table 1].

Table 1.

Study participant demographics, prosthesis characteristics and oral hygiene practices among denture wearers (N = 298)

Characteristic	Category/level	N (%)
Age (years)	20–30	130 (43.6%)
	30–40	56 (18.8%)
	40–50	65 (21.8%)
	50–60	47 (15.8%)
Gender	Male	183 (61.4%)
	Female	115 (38.6%)
Chronic diseases	Yes	71 (23.8%)
	No	227 (76.2%)
Prosthesis type	Fixed partial denture	195 (65.4%)
	Removable partial denture	81 (27.2%)
	Both (fixed + removable)	22 (7.4%)
Duration of prosthesis use	< 1 year	93 (31.2%)
	1–3 years	109 (36.6%)
	3–5 years	55 (18.5%)
	> 5 years	41 (13.8%)
Cleans prosthesis regularly	Yes	167 (56.0%)
	No	131 (44.0%)
Daily cleaning frequency	None (does not clean) or irregular	21 (7%)
	Once daily	128 (43.0%)
	Twice daily	145 (48.7%)
	Three times daily	4 (1.3%)
Prosthesis cleaning method (multiple responses possible)	Toothbrush	252 (84.6%)
	Miswak (chewing stick)	23 (7.7%)
	Antiseptic gargle/mouthwash	18 (6.0%)
	Dental floss	5 (1.7%)
Dental visit interval	None	109 (36.6)
	Once every 3 months	25 (8.4)
	Once every 6 months	84 (28.2)
	Once in a year	80 (26.8)
Regular dental visits	Yes	148 (48.7)
	No	150 (50.3)

KNOWLEDGE AND AWARENESS OF PROSTHESIS CARE

The assessment of participant awareness revealed a mixed but insightful understanding of dental prostheses. A majority of participants (71.5%) correctly believed that a prosthesis requires special care to function normally, and nearly two-thirds (64.8%) were aware of its role in maintaining bone and gum levels. Furthermore, over half of the respondents recognized that prostheses can affect adjacent natural teeth (54.4%) and noticed differences between their natural teeth and dentures (54.0%).

However, significant knowledge gaps were identified. A substantial proportion (70.1%) lacked information about the different types of prostheses available, and a similar majority (70.1%) reported no change in their diet after receiving the prosthesis. Attitudes toward the psychosocial impact of prostheses were divided, with the cohort almost evenly split on whether it affects social life or self-confidence (49.0% yes vs. 51.0% no).

While participants demonstrated good awareness of the functional and biological aspects of prosthetic care, there was a notable deficit in knowledge regarding prosthetic types and a varied perception of its broader impacts on daily life and well-being [Table 2].

Table 2.

Patient knowledge and awareness regarding dental prostheses (yes/no responses)

Question (awareness item)	Yes, n (%)	No, n (%)
Has information about different types of prosthesis?	89 (29.9%)	209 (70.1%)
Notices differences between natural teeth and dentures?	161 (54.0%)	137 (46.0%)
Believes prosthesis can affect social life or self-confidence?	146 (49.0%)	152 (51.0%)
Believes prosthesis needs special care for normal function?	213 (71.5%)	85 (28.5%)
Diet changed after getting the prosthesis?	89 (29.9%)	209 (70.1%)
Believes prosthesis helps maintain normal bone and gum levels?	193 (64.8%)	105 (35.2%)
Believes dentures can affect adjacent natural teeth?	162 (54.4%)	136 (45.6%)

PROSTHESIS-RELATED COMPLICATIONS

A substantial proportion of participants (approximately two-thirds) reported complications related to their prosthesis. The most prevalent issue was halitosis (bad breath), affecting 38.9% of respondents. This was followed by gingival bleeding (25.8%) and swelling (24.2%). Less frequent complications included tooth sensitivity (12.4%), Temporomandibular joint discomfort (7.4%), and speech difficulties (4.4%). Conversely, 35.2% of participants reported no adverse effects. The predominance of halitosis underscores the critical need for enhanced patient education on prosthesis hygiene to mitigate plaque-related complications [Figure 1].

Figure 1.

Prosthesis-related complications reported by patients. Note: Multiple responses were allowed; each bar represents the percentage of all participants who reported that specific issue

PERIODONTAL HEALTH STATUS OF PROSTHESIS WEARERS

The assessment of periodontal health status, as presented in Figure 2, reveals a high prevalence of suboptimal oral conditions among participants. The distribution of the PI shows that the majority (75.2%) exhibited some level of plaque accumulation, with 41.9% presenting mild deposits and 33.2% exhibiting moderate-to-severe levels. Similarly, the GI scores indicated that gingival inflammation was widespread, affecting 72.8% of the cohort. Notably, moderate inflammation was the most common finding (34.9%), suggesting a significant tissue response to local irritants. For the calculus index, 63.8% of participants had detectable calculus, with mild deposits being most frequent (39.6%). The presence of moderate-to-severe calculus in nearly a quarter of the sample points to chronic issues with oral hygiene maintenance. The data demonstrates a clear burden of plaque, gingivitis, and calculus within the study population, underscoring the critical need for enhanced oral hygiene interventions and professional care [Figure 2].

Figure 2.

Distribution of periodontal index grades. Distribution of plaque, gingival, and calculus index grades. (Grade 0 indicates no plaque/gingivitis/calculus, while Grade 3 indicates severe levels.)

ASSOCIATIONS BETWEEN PATIENT FACTORS AND PERIODONTAL INDICES

Plaque

Table 3 presents univariable and multivariable logistic regression analysis to identify independent factors associated with a high PI, using a low PI as the reference category. The model included all variables that demonstrated statistical significance (P ≤ 0.05) in the initial univariate analysis. The final adjusted model revealed that prosthesis cleaning habit and daily cleaning frequency were the only factors that remained statistically significant independent predictors of plaque levels after controlling for other covariates.

Table 3.

Logistic regression analysis; factors association with high plaque index

Plaque index		Univariate			Multivariable
Characteristic	Category/level	COR	95% CI	P value	AOR	95% CI	P value
Age (years)	20–30	Reference		0.000002 *	Reference		0.432
	30–40	1.274	(0.619–2.621)		0.891	(0.374–2.124)
	40–50	1.907	(0.991–3.672)		0.908	(0.381–2.165)
	50–60	7.430	(3.547–15.562)		1.901	(0.649–5.571)
Gender	Female	Reference		0.087	–	–	–
	Male	0.651	(0.398–1.064)		–	–
Prosthesis cleaning habit	No	Reference		6.95 × 10 − 7 *	Reference		0.032 *
	Yes	0.278	(0.167–0.460)		0.508	(0.274–0.944)
Dental visit interval	None	Reference		0.000211 *	Reference		0.093
	Once every 3 months	0.64	(0.26–1.572)		2.521	(0.679–9.355)
	Once every 6 months	0.208	(0.103–0.420)		0.607	(0.207–1.784)
	Once in a year	0.548	(0.300–0.998)		1.036	(0.437–2.455)
Regular dental visits	No	Reference		0.000312 *	Reference		0.821
	Yes	0.399	(0.243–0.658)		0.905	(0.379–2.159)
Daily cleaning frequency	None (does not clean) or irregular	Reference		2.51 × 10 − 8 *	Reference		0.035 *
	Once daily	0.455	(0.172–1.202)		0.859	(0.292–2.530)
	Twice daily	0.094	(0.034–0.259)		0.307	(0.089–1.059)
	Three times daily	0.167	(0.015–1.909)		0.678	(0.048–9.661)
Duration of prosthesis use	< 1 year	Reference		0.000311 *	Reference		0.356
	1–3 years	1.425	(0.753–2.695)		1.239	(0.582–2.641)
	3–5 years	2.118	(1.021–4.392)		1.014	(0.385–2.667)
	> 5 years	5.357	(2.422–11.848)		2.263	(0.803–6.374)
Chronic diseases	No	Reference		0.007 *	Reference		0.82
	Yes	2.118	(1.225–3.662)		1.087	(0.529–2.231)
Prosthesis type	Fixed partial denture	Reference		0.00004 *	Reference		0.085
	Removable partial denture	3.59	(2.074–6.213)		1.573	(0.788–3.138)
	Both (fixed + removable)	4	(1.622–9.867)		3.062	(1.066–8.80)

COR = crude odds ratio, AOR = adjusted odds ratio, CI = confidence interval.

^*P value ≤ considered as significant,

Prosthesis cleaning habit: The habit of cleaning one’s prosthesis emerged as a strong protective factor. Individuals who reported cleaning their prosthesis had 49.2% lower odds of having a high PI compared to those who did not (AOR = 0.508; 95% CI: 0.27–0.94; P value = 0.032).

Daily cleaning frequency: The frequency of daily oral hygiene was also a significant independent predictor. The overall variable was significant (P = 0.035). A clear dose-response trend was observed. Specifically, brushing twice daily was associated with a 69.3% reduction in the odds of high plaque (AOR = 0.307; 95% CI: 0.09–1.06) compared to irregular or no cleaning, though the upper confidence interval marginally crossed the null value of 1.0. Brushing once daily or 3 times daily did not show a statistically significant association in the adjusted model. Other factors: Several factors that were significant in the univariate analysis lost their independent association in the multivariable model. Notably, the strong univariate associations of older age (50–60 years), longer duration of prosthesis use (>5 years), and having a removable prosthesis were weakened and became non-significant after adjustment. This suggests that their initial strong association with high plaque may be mediated or confounded by other factors in the model, such as cleaning habits. Similarly, the presence of chronic diseases and regular dental visits was not independent predictors in the final model.

After controlling potential confounders, behavioral factors related to prosthesis and oral hygiene maintenance specifically, the habit of cleaning the prosthesis and the frequency of brushing teeth were the most significant independent determinants of a high PI in this study population [Table 3].

Gingival

A multivariable logistic regression model was constructed in Table 4 to identify independent determinants of a high GI, controlling for potential confounders among variables significant in univariate analysis. The results indicate that prosthesis cleaning habits and dental visit intervals are significant independent predictors of gingival inflammation.

Table 4.

Logistic regression analysis; factors association with high gingival index

Gingival		Univariate			Multivariable
Characteristic	Category/level	COR	95% CI	P value	AOR	95% CI	P value
Age (years)	20–30	Reference		0.001 *	Reference
	30–40	1.75	(0.915–3.348)		1.575	(0.793–3.126)	0.275
	40–50	1.88	(1.015–3.481)		1.465	(0.753–2.851)
	50–60	4.118	(2.038–8.320)		2.099	(0.924–4.769)
Gender	Female	Reference		0.051	–	–	–
	Male	1.617	(0.997–2.623)		–	–
Prosthesis cleaning habit	No	Reference		0.00004	Reference
	Yes	0.372	(0.231–0.598)		0.54	(0.317–0.920)	0.024 *
Dental visit interval	None	Reference		0.00005 *	Reference
	Once every 3 months	0.443	(0.180–1.089)		0.54	(0.166–1.754)	0.044 *
	Once every 6 months	0.215	(0.113–0.409)		0.27	(0.106–0.692)
	Once in a year	0.582	(0.325–1.042)		0.601	(0.279–1.295)
Regular dental visits	No	Reference		0.002 *	Reference
	Yes	0.471	(0.294–0.753)		1.315	(0.608–2.844)	0.486
Duration of prosthesis use	< 1 year	Reference		0.106
	1–3 years	1.149	(0.645–2.047)		–	–	–
	3–5 years	1.977	(1.001–3.902)		–	–
	> 5 years	2.002	(.948–4.225)		–	–
Chronic diseases	No	Reference		0.014 *	Reference		0.304
	Yes	1.96	(1.144–3.359)		1.393	(0.741–2.619)
Prosthesis type	Fixed partial denture	Reference		0.146
	Removable partial denture	1.667	(0.987–2.814)		–	–	–
	Both (fixed + removable)	1.424	(0.586–3.460)		–	–

COR = crude odds ratio, AOR = adjusted odds ratio, CI = confidence interval

^*P value ≤ considered as significant

Prosthesis cleaning habit: Consistent cleaning of the prosthesis was confirmed as a significant protective factor against gingival inflammation. Individuals who cleaned their prosthesis had a 46% reduction in the odds of having a high GI compared to those who did not (AOR = 0.54; 95% CI: 0.32–0.92; P value = 0.024).

Dental visit interval: The frequency of dental visits was also a significant independent predictor in the model (P value = 0.044). A particularly strong protective effect was observed for individuals who visited a dentist once every 6 months. This group had a 73% reduction in the odds of high gingival inflammation compared to those who never had routine dental visits (AOR = 0.27; 95% CI: 0.11–0.69). Other visit intervals (once every 3 months or once a year) did not show a statistically significant association in the adjusted model.

Several factors that were significant in the univariate analysis did not retain their independent association in the final model. The strong crude association observed for older age (50–60 years) was weakened and became non-significant after adjustment (AOR = 2.10; 95% CI: 0.92–4.77; P value = 0.275), suggesting that its effect may be mediated through other variables like oral hygiene practices. Similarly, the presence of chronic diseases and reporting regular dental visits lost their statistical significance after controlling covariates, particularly the specific interval of dental visits. The findings underscore that modifiable behavioral factors specifically, regular prosthesis maintenance, and semiannual professional dental care are key independent factors associated with better gingival health in this patient population with prostheses [Table 4].

Calculus

The multivariable logistic regression analysis for factors associated with a high calculus index revealed in Table 5 a distinct pattern compared to the models for plaque and gingival inflammation. Notably, prosthesis type emerged as the sole significant independent predictor in the final model, while behavioral factors like cleaning habits showed a notable but non-significant trend.

Table 5.

Logistic regression analysis; factors association with high calculus index

Calculus		Univariate			Multivariable
Characteristic	Category/level	COR	95% CI	P value	AOR	95% CI	P value
Age (years)	20–30	Reference		0.07
	30–40	1.537	(0.737–3.204)			–	–
	40–50	1.153	(0.553–2.404)			–
	50–60	2.607	(1.254–5.421)			–
Gender	Female	Reference		0.538		–	–
	Male	0.844	(0.492–1.449)			–
Prosthesis cleaning habit	No	Reference		0.012 *			0.08
	Yes	0.5	(0.292–0.856)		1.65	(0.942–2.889)
Dental visit interval	None	Reference		0.085			–
	Once every 3 months	0.727	(0.266–1.986)			–
	Once every 6 months	0.384	(0.184–0.801)			–
	Once in a year	0.82	(0.430–1.561)			–
Regular dental visits	No	Reference		0.381
	Yes	0.788	(0.463–1.342)			–
Duration of prosthesis use	< 1 year	Reference		0.621
	1–3 years	0.867	(0.442–1.702)		–	–	–
	3–5 years	1.171	(0.538–2.547)		–	–
	> 5 years	1.978	(0.889–4.403)		–	–
Chronic diseases	No	Reference		0.031 *	Reference		0.242
	Yes	1.904	(1.060–3.421)		1.452	(0.777–2.713)
Prosthesis type	Fixed partial denture	Reference		0.003 *	Reference
	Removable partial denture	2.549	(1.423–4.568)		2.075	(1.119–3.846)	0.030 *
	Both (fixed + removable)	2.612	(1.018–6.704)		2.41	(0.927–6.270)

COR = crude odds ratio, AOR = adjusted odds ratio, CI = confidence interval

^*P value ≤ considered as significant

Prosthesis type: The type of dental prosthesis was a significant independent risk factor for calculus accumulation. Compared to individuals with FPDs, those with RPDs had more than twice the odds of having a high calculus index (AOR = 2.08; 95% CI: 1.12–3.85; P value = 0.030). The point estimate for individuals with both fixed and removable prostheses was even higher (AOR = 2.41) but was not statistically significant (95% CI: 0.93–6.27).

In contrast to the findings for plaque and gingival indices, behavioral factors did not retain clear statistical significance in this model. While prosthesis cleaning habit was a significant protective factor in the univariate analysis (COR = 0.50, P value = 0.012), its effect was weakened and became non-significant after adjusting for other variables, particularly prosthesis type (AOR = 1.65; 95% CI: 0.94–2.89; P value = 0.08). The presence of chronic diseases, significant in univariate analysis, was also no longer significant in the adjusted model. No other variables, including age, dental visit patterns, or duration of use, were significant independent predictors of a high calculus index.

The analysis indicates that the physical nature of the prosthesis itself specifically, having a removable denture is the primary independent risk factor associated with increased calculus formation [Table 5].

The multivariable analyses revealed distinct and specific risk profiles for plaque accumulation, gingival inflammation, and calculus formation. For both plaque and gingival health, modifiable behavioral factors were dominant; specifically, the habit of cleaning a prosthesis was a significant independent protective factor for both conditions, and six-monthly dental visits were additionally protective against gingival inflammation. In contrast, the primary determinant of a high calculus index was a non-modifiable prosthetic factor, with RPDs significantly increasing the risk, while behavioral factors lost their significance. This divergence highlights that while proactive hygiene and professional care are crucial for managing soft tissue health (plaque and gingivitis), the physical design of the prosthesis itself is a dominant factor in the hard deposit (calculus) formation, that is, less easily mitigated by patient behavior alone.

DISCUSSION

ORAL HYGIENE AND PERIODONTAL STATUS

This study assessed the periodontal health of partial denture wearers in Al-Ahsa and found a significant proportion with moderate-to-severe plaque accumulation and gingival inflammation. More than one-third of the participants had PI scores of Grade 2 or 3, and over 40% demonstrated signs of gingivitis, consistent with prior findings that denture wearers are at increased risk of periodontal deterioration if hygiene is suboptimal.[16,20] The design of fixed and removable prostheses often introduces new surfaces prone to plaque retention, especially around abutment teeth and under pontics or clasps. If patients do not compensate with diligent cleaning, biofilm accumulation, and inflammation follow. In our cohort, those who cleaned their prosthesis daily and brushed twice a day had significantly better periodontal outcomes, mirroring results from other clinical studies.[12]

Cakan et al. reported that long-term use of RPDs did not impair periodontal health when proper hygiene was maintained.[21] Similarly, Cakan et al. found that lack of professional instruction was associated with poor denture hygiene, candidal growth, and higher plaque levels.[21] Our finding that 44% of patients did not clean their prosthesis regularly, and that these individuals had worse plaque and GI scores, reinforces the central role of hygiene behavior in maintaining periodontal stability. In addition to clinical outcomes, poor hygiene can associate with social and psychological well-being. Although our results section did not statistically analyze direct correlations between poor cleaning habits and self-reported complications, it is plausible and inferred from observed patterns and prior literature that patients with inadequate prosthesis hygiene practices are more likely to report symptoms such as halitosis and gingival bleeding.[17,22]

In summary, plaque-related periodontal disease in partial denture wearers appears largely preventable with consistent hygiene. Our data, supported by other studies, confirm that patient adherence to daily cleaning and professional guidance significantly improves outcomes. This is clearly reflected in the Table 3 where participants with infrequent cleaning habits exhibited higher odds of high PI.

COMPARISON OF FIXED VERSUS REMOVABLE PROSTHESES

Our analysis revealed that prosthesis type was not an independent predictor for either plaque or GI. This suggests that the initial, unadjusted association seen in the univariate models was likely confounded by behavioral factors. This is consistent with findings from Wennström et al.[23] and a recent systematic review,[21] who noted similar rates of attachment loss across both groups after 5 years, provided oral hygiene was maintained.[23]

It appears that with meticulous hygiene and professional care factors that were significant in our models for plaque and gingivitis the inflammatory risks associated with both fixed and removable prostheses can be mitigated.

While RPDs have traditionally been viewed as more damaging to the periodontium due to their contact with gingival tissues and movement of clasps, our data suggest that fixed prostheses also carry risk if not properly maintained. Jespen et al. found that abutment teeth of RPDs often had worse periodontal indices than non-abutments.[2] Likewise, Al-Sinaidi and Preethanath[3] demonstrated higher inflammation around crowned abutments of fixed bridges.

In contrast, the type of prosthesis emerged as the sole significant independent predictor for a high calculus index. Patients with RPDs had over twice the odds (AOR = 2.08) of significant calculus formation compared to those with FPDs. This finding is consistent with the biomechanical challenges posed by RPDs. The components of a removable denture, such as clasps and acrylic bases, create additional, often difficult-to-clean niches for plaque retention and alter the flow of saliva, facilitating the precipitation of salivary minerals.[24,25]

What matters most is not the type of prosthesis but the maintenance routine. Both fixed and removable designs demand tailored hygiene protocols. Neglect on either front result in comparable periodontal compromise, as we observed in patients with poor plaque control, regardless of prosthesis type.

PATIENT AWARENESS AND EDUCATION

A notable finding in this study was the limited awareness among participants regarding prosthesis care. Over 70% of respondents had no knowledge of different prosthesis types, and more than half were unaware that dentures could affect adjacent teeth. This highlights a critical gap in patient education and suggests that pretreatment counseling may often be insufficient. Similar deficiencies have been reported in other settings, including by Milward et al.[9] who found that while many patients claimed to have received hygiene instructions, their actual knowledge was lacking and compliance was poor. Only a minority of our participants used interdental aids such as floss or superfloss, despite the presence of prosthetic designs, like fixed bridges, that require floss threaders for effective cleaning. This is in line with broader findings in the region, where studies have reported low rates of floss use, even among dental professionals.[26] Among our cohort, only 1.3% reported regular flossing, which is concerning given its role in cleaning under pontics and between abutments.

Alternative hygiene tools, such as the traditional miswak, were used by a small subset of patients. Interestingly, those who used miswak often had lower plaque scores, perhaps reflecting either effective mechanical cleaning or a more hygiene-conscious profile. The previous studies have confirmed that when properly prepared and used, miswak can be as effective as a toothbrush in plaque removal.[10,11] However, it requires correct technique and regular maintenance and may not be suitable as a sole method for prosthesis hygiene. Halitosis emerged as a common self-reported complication, with over one-third of patients citing persistent halitosis. This may be due to plaque accumulation on or beneath prosthetic surfaces, especially if not adequately cleaned. A study from Abha, Saudi Arabia, found that 71% of denture wearers had never used any commercial denture cleaning products, relying only on water rinsing, which was ineffective in preventing odor or buildup.[27] None of our RPD users mentioned using denture cleansers, pointing to a widespread lack of awareness or access.[21]

Educational interventions, especially those involving demonstration and follow-up, can significantly improve outcomes. When patients are shown how to brush their dentures, use floss threaders or soak prostheses properly, both gingival health and satisfaction improve. Several studies have affirmed that education and motivation play a pivotal role in prosthetic success.[16,28,29] Yet, our data suggest that routine education is either not being delivered or not being retained.

In summary, while patients may broadly agree that dentures require special care, they often lack the practical knowledge to carry it out. This emphasizes the need for structured, repeated oral hygiene instruction as part of prosthodontic care, not just during delivery but across follow-up visits.

COMPARISON WITH OTHER STUDIES

Our findings align with prior regional and international research. Elmahdi et al.,[1] in a study from Aseer, reported high plaque scores among older RPD wearers, with 78% medically fit and 22% diabetic, figures nearly identical to our sample. While their cohort skewed older, both studies demonstrated that plaque and gingivitis were prevalent in prosthesis users lacking consistent hygiene. Interestingly, our sample included a younger demographic, predominantly under 45 years, possibly due to the university clinic setting. Yet even in this younger group, plaque and gingival inflammation were prominent, suggesting behavioral rather than biological drivers. These behavioral associations are supported by the statistics detailed in Table 3, where age, prosthesis cleaning, and cleaning frequency all demonstrated significant associations with higher PI. Age and prosthesis cleaning habits were associated with a high GI [Table 4]. Furthermore, prosthesis cleaning was also associated with a high calculus index [Table 5].

The significance of hygiene behavior over age has been underscored by others.[22] Zhu et al. found that although edentulism and denture use increased with age, oral health outcomes depended largely on hygiene practices and follow-up care.[30] Similarly, Bloomfield et al. demonstrated that among elderly patients, root caries and inflammation were more closely linked to salivary factors and hygiene status than chronological age alone.[31] Gender did not significantly associated with periodontal indices in our sample, although females demonstrated a slight trend toward better hygiene. This trend has been observed elsewhere and attributed to generally higher oral health awareness and more frequent dental visits among women.[26] For instance, Has et al. reported that older females consistently had better nutrition and oral hygiene, which contributed to more favorable periodontal profiles.[32] However, the limited number of female participants in our study restricts the generalisability of this trend.

CLINICAL IMPLICATIONS

The results of this study have several practical implications for dental professionals:

• First, it is evident that effective plaque control around partial dentures depends heavily on patient compliance and understanding. Many of the complications observed, including halitosis, gingival inflammation, and plaque-related calculus accumulation, can be mitigated with appropriate hygiene practices. Therefore, clinicians should prioritize patient education during prosthesis delivery and reinforce it during follow-up visits.

• Educational strategies should include demonstrations of proper cleaning methods, especially for hard-to-reach areas beneath pontics or around clasp-retained abutments. Tools such as floss threaders, interdental brushes, and denture cleansers should be introduced, and patients should be instructed in their use. The clinical impact of such interventions is underscored by data in Table 5, which show a strong association between improved hygiene behavior and reduced plaque and gingival scores. Written or visual aids may assist reinforce these messages at home. Research by Walton et al.[33] suggests that inadequate patient instruction is a major cause of early prosthesis failure.[34]

• In addition to hygiene, prosthesis design must support cleanability. Fixed prostheses should have supragingival margins when feasible, and pontics should be shaped to allow easy cleaning. Similarly, RPDs should minimize gingival coverage and incorporate self-cleansing design features. Poor design not only complicates hygiene but also exacerbates plaque accumulation. Caruana found that prosthetic success was significantly higher when design choices supported hygiene accessibility.[35] Bad breath was a commonly reported complaint among participants. Dentists should proactively address this issue during recall appointments. Plaque accumulation on denture surfaces, the tongue, or in hard-to-reach zones can produce volatile sulfur compounds. Simple interventions such as recommending tongue scrapers, antiseptic rinses, or regular denture soaking can improve comfort and social confidence.

• Finally, patients with systemic risk factors, such as diabetes, should be integrated into more frequent recall schedules. Periodontal vulnerability is heightened in such individuals, and regular monitoring allows for early intervention if inflammation or plaque accumulation worsens.

LIMITATIONS

This study has several limitations. As a cross-sectional study, it provides only a snapshot in time and cannot establish causality. Longitudinal data would be required to determine how prosthesis use directly affects periodontal status over time.

The findings on oral hygiene practices are based on self-reported data, which are susceptible to social desirability and recall bias. Participants may have over-reported positive behaviors, such as brushing frequency or regular prosthesis cleaning, leading to a potential underestimation of the true prevalence of poor oral hygiene habits.

Another limitation is its reliance on a convenience sampling method. This approach inherently limits the representativeness of the sample, as participants were recruited solely from a university dental clinic. Consequently, the findings may reflect a specific subset of the population such as those with higher health awareness or more complex dental needs and may not be generalizable to all prosthesis wearers in the Al-Ahsa region.

The absence of radiographic data is another limitation, as bone loss and hidden caries under prostheses were not assessed. Finally, while prosthesis type and location were documented, detailed design variables (e.g., clasp type, pontic shape, and Kennedy classification) were not examined. These could influence outcomes and should be included in future analyses.

FUTURE DIRECTIONS

Future research should focus on longitudinal studies that assess periodontal outcomes before and after prosthesis delivery. This would assist determine causation and allow researchers to evaluate the impact of different prosthesis designs and hygiene instructions over time. Randomized controlled trials could also evaluate the effectiveness of structured hygiene education programs. Patients could be assigned to receive standard versus enhanced instructions, with plaque scores, gingival inflammation, and patient-reported outcomes tracked over several months.

Innovative educational tools, such as mobile apps or text-based reminders, could also be tested for their ability to improve patient compliance with prosthesis care. Furthermore, qualitative research including patient interviews could uncover barriers to effective hygiene, such as discomfort, lack of knowledge, or perceived complexity. Finally, research into design-specific risk factors (e.g., clasp stress and subpontic space) could guide more hygienic prosthodontic fabrication in clinical practice. Studies comparing digital versus conventional prosthesis designs may also provide insights into whether newer technologies offer periodontal advantages.

CONCLUSION

This study reveals a critical gap between knowledge and practice among dental prosthesis wearers, reflected in poor periodontal health status marked by a high prevalence of moderate-to-severe plaque and gingival inflammation. The key finding is a clear divergence in risk factors: behavioral factors (prosthesis cleaning and brushing frequency) are the primary determinants of plaque and gingival health, while the prosthesis type (specifically, RPDs) is the dominant risk factor for calculus formation.

Therefore, effective management requires a dual strategy: (1) enhanced patient education to improve hygiene practices for controlling soft tissue inflammation, and (2) intensified professional maintenance for wearers of removable dentures to mitigate prosthesis-driven calculus accumulation and preserve periodontal health.

CONFLICTS OF INTEREST

There are no conflicts of interest.

ETHICAL POLICY AND INSTITUTIONAL REVIEW BOARD STATEMENT

Ethical approval was obtained from the institutional review board of KFU with reference number KFU-REC-2024-MAR-ETHICS2152.

PATIENT DECLARATION OF CONSENT

Informed consents were taken from the participants.

AUTHORS CONTRIBUTIONS

All authors contributed equally.

DATA AVAILABILITY STATEMENT

Not applicable.

LIST OF ABBREVIATIONS

• RPDS removable partial dentures

• GI gingival index

• CSI calculus surface index

• FPDs fixed partial dentures

• KFU King Faisal University

• AOR adjusted odds ratios

APPENDIX A: PARTICIPANT QUESTIONNAIRE

The following items were administered in a structured interview format to collect data from participants:

DEMOGRAPHICS AND MEDICAL HISTORY

• 1.What is your age group?
  • ○20–30
  • ○30–40
  • ○40–50
  • ○50–60
• 2.What is your gender?
  • ○Male
  • ○Female
• 3.Do you have any chronic health conditions?
  • ○Yes
  • ○No
• 4.If yes, please specify the condition:
  • ○Diabetes
  • ○Other (specify)

ORAL HYGIENE PRACTICES

• 5.What method(s) do you use for oral hygiene? (Select all that apply)

  • Toothbrush

  • Miswak

  • Gargle/mouthwash

  • Dental floss

• 6.How often do you clean your teeth per day?

  • None

  • Once daily

  • Twice daily

  • Three times daily

  • Less than once daily (weekly, etc.)

• 7.Do you clean your dental prosthesis specifically (in addition to brushing)?

  • Yes

  • No

• 8.Do you visit a dentist for regular check-ups?

  • Yes

  • No

• 9.If yes, how often do you visit the dentist?

  • Every 3 months

  • Every 6 months

  • Every 9 months

  • Once a year

  • Not at all

• 10.How long has it been since you’ve had prosthesis??

  • < 1 year

  • 1–3 years

  • 3–5 years

  • > 5 yeas

• 11.Are there any side effects that you noticed after the prosthesis?

KNOWLEDGE AND AWARENESS

• 12.Do you have information about different types of dental prosthesis?

  • Yes

  • No

• 13.Have you noticed any difference between your prosthetic and natural teeth?

  • Yes

  • No

• 14.Do you believe a dental prosthesis can affect:
  • a.Your social life or self-confidence?
  • b.Your diet or eating habits?
  • c.The adjacent natural teeth?
  • d.The bone and gum levels?

• Yes/ No (for each item)

• 15.Do you think a dental prosthesis requires special care to function properly?

  • Yes

  • No

• 16.Do you have information about the various types of prosthesis?

  • Yes

  • No

• 17.Do you think that dental prosthesis helps maintain the normal level of bone and gums?

  • Yes

  • No

• 18.Do you think that dentures can affect the teeth next to them in any way?

  • Yes

  • No

Funding Statement

Nil.