Introduction

Teeth loss may affect facial appearance, mastication, and speech [1], which, as a result, has a huge impact on general and oral health and eventually on the quality of life [2]. Hence, replacing the missing teeth with suitably constructed prostheses is highly demanded. Partially edentulous patients have various treatment options to replace missing teeth. These might include prostheses supported by implants, conventional fixed partial dentures (FPDs), or removable partial dentures (RPDs) [3]. RPDs are a common choice that is usually prescribed over FPDs or implant-supported prostheses for partially edentulous patients, especially when a relatively low cost and noninvasively alternative is indicated [4-6]. RPDs could provide preservation of the existing tissue, improve phonetics and chewing performance, as well as enhance esthetics [7]. However, the patient compliance to continuously wearing removable partial dentures has been reported by Jepson et al., 1995 to be as low as 60% [3]. In their study, it was found that replacing anterior teeth with dentures is a considerable factor in the compliance of the patients to wear them. The study showed that most of the non-wearers were having dentures that does not replace the anterior teeth [3].

Biological, psychological, mechanical, and esthetic factors have been demonstrated to be related to RPDs acceptance and success [6]. Satisfaction with removable partial dentures was also associated with mechanical factors such as denture fit, number of missing teeth, and retention. In addition, mastication and phonetics are considerable factors, while age and hygiene factors are not correlated with satisfaction [6]. The personality of the patient and physical adaptability and social adaptation was found to be associated with satisfaction with RPDs [5]. The stomatognathic system in new dentures wearer requires some time to reach adaptation and acceptance [8]. A duration of 6 to 8 weeks was suggested for determining adequate usage of the new dentures, as the capacity to develop new patterns of memory for muscles of mastication can be achieved during this period [9]. Most often, edentulous people spend prolonged spans without dentures, thus they have greater trouble learning to masticate with new dentures, and the time for adaptation is expected to be longer [9].

By valuing appearance for RPDs, creative clasp design provides the possibility of reducing the visibility of clasp, making them more acceptable to patients [8]. Additionally, patient acceptance is influenced by denture retention, support, and chewing ability [7]. As various interrelating factors could have a direct or indirect effect on patient acceptance of RPDs, this study aims to investigate the interaction between some of these factors with a focus on replacing the anterior teeth and its impact on patient acceptance and continuity of using their RPDs. This can assist clinicians in predicting the prognosis of their treatment, as well as patients in treatment selection and understanding the treatment's risks.

Materials and Methods

In total, 147 randomly selected patients were recruited for the study. These patients were treated with removable partial dentures (RPD) during undergraduate courses at the College of Dentistry, Prince Sattam bin Abdulaziz University and Al Farabi College of Dentistry and Nursing. The permission to carry out the study was obtained from the institutional ethical committee before conducting the study. Out of the 147, 104 responded while 37 did not respond, and the remaining 6 refused to participate. Of the total responses, the gender distribution was 64 males (61.5%) and40 females (38.4%). Patients were treated by undergraduate dental students supervised by experienced specialist faculty members. A self-administered validated questionnaire was developed for the study.  Items for the questionnaire were developed through a literature search and an expert focus group consisting of an assistant professor in prosthodontics (IA), a prosthodontics consultant (AA), and one psychometric statistician (SK). A pilot study and pretesting of the questionnaire were conducted on a sample of 27 participants that were also included in the final survey. A principal components analysis (PCA) was conducted to examine the factor structure of the questionnaire. The questionnaire items were then tested for reliability using the Cronbach’s coefficient alpha measure of internal consistency. The overall internal reliability of the questionnaire was 0.89 which indicates good internal consistency.

Before starting the survey, the authors estimated the sample size. The author asked around 147 patients to be part of the study. (The margin error was kept at 0.5 and the confidence level at 95 percent). The effective sample size came out to be 100 since one can expect subjects to leave the study in between because of various reasons, so the total sample was taken [10].

Patients were contacted by research contributors using the telephone and then asked about their experience and satisfaction with the provided dentures based on the prepared questionnaire (a set of [11] questions). Based on their responses, they were distributed into two groups: The first group included patients who have had RPDs replacing anterior teeth (esthetic area) while the second group included patients who have had RPDs replacing posterior teeth only. The questionnaire consisted of information about the patient’s age, gender, education, and income. The highest level of confidentiality was applied to start by collecting the sample using the colleges' file systems after getting official approval. Respondents were asked for their verbal and written approval to contribute to the survey and assured of the confidentiality of handling their contact information and their responses.

Statistical analysis

Data were coded, tabulated into spreadsheet software (Microsoft Excel (2010)) and analyzed using SPSS (Statistical Package for Social Sciences; IBM SPSS Statistics for Windows, Version 26.0. Armonk, NY: IBM Corp). Descriptive statistics were used to calculate the frequency and distribution of demographic variables like gender, age, education, income, and nationality that were presented as numbers and percentages. The frequency distribution of participant responses to each question was also presented as numbers and percentages. Pearson’s chi-square tests were used to compare responses of participants between gender, age, and other demographic variables. A p-value less than 0.05 was considered statistically significant.

Results and Discussion

The education level of the participants, 57% were up to the primary level of education, followed by 16% with the secondary level, 15%holding a Diploma, and 12% with a bachelor’s degree. The participants aged from 42 years old to 81 years old, and the majority of the participants were between 51 and 60 years old (44%), followed by the age class of 61 – 70 years old (30%), and the younger class 40– 50 years old (23%). The participants were questioned about the area of their mouth which was replaced by the denture. Possible answers were “replacement of anterior teeth” or “replacement of only back teeth”. Of all the participants, 71% stated that the anterior teeth were replaced by the denture, while 29% stated that only the back teeth were replaced Table 1.

Table 1. Total number of answers related to the area of replacement of the mouth by the denture according to gender, education level, and age class of the participants

The relationship between satisfaction with the denture and the remaining variables (through Chi-squared tests) is summarized in Table 2. Satisfaction was found to be related to four of the considered variables in the research. A question of interest was if there was any influence of the area replaced by the denture on the satisfaction of the participants. No relationship between both factors could be found in the investigation (chi-square test, p = 0.45) Table 2.

Table 2. Summary for the Chi-squared tests performed to assess the association between satisfaction with the denture and other factors

“p-value” indicates the p-value of the corresponding Chi-squared test. Asterisk (*) indicates statistically significant associations

However, a trend for an increase in the percentage of dissatisfied participants could be observed when just the back teeth were replaced by the denture Nevertheless, this trend was not statistically significant. A significant relationship was observed between the current use of dentures and satisfaction (Chi-squared test p < 0.001). The adaptation time was also directly associated with the satisfaction of the users (chi-square test, p < 0.001). Satisfied users typically need no more than two months to adapt to the denture (Table 2). The two most common reasons hindering the use of dentures were “Denture is causing some pain” (33.3% of participants who were not using dentures) and “Denture is loose” (42.9% of participants who were not using dentures) Table 3.

Table 3. Summary statistics for the answers to the research questions

The majority of participants who were currently using dentures reported being satisfied while the majority of those who sometimes use or don’t use dentures reported being dissatisfied (Figure 2).

The hours of use of the denture is also a direct consequence of the satisfaction (chi-square test, p < 0.001). People must be satisfied to use the denture for longer periods. Almost the totality of the participants who were completely satisfied stated to use the denture for periods longer than 8 hours, at the same time that moderately satisfied people used the denture for at least more than 3 hours (Figure 3).

Most of the users with complete satisfaction adapt to the denture before the end of the first month of use, and those with moderate satisfaction adapt before the end of the second month (Figure 4).