Evaluation and comparison of patient satisfaction with VertexThermosens and conventional acrylic complete dentures

Abstract Objectives Patient perception and satisfaction with dentures are important indicators in prosthodontic treatment. This study aimed to compare patients' satisfaction with VertexThermosens dentures versus conventional acrylic dentures during a 12‐month study period. Material and Methods This randomized study involved 60 participants aged between 45 and 80 with representation of both sexes. The patients were divided into two groups: The first group (experimental group), which had complete dentures from VertexThermosens base material included 30 participants. The second group (control group), which had complete dentures from convectional rigid acrylic base material, included 30 participants. Patient satisfaction with the dentures was assessed in each of the two Vertex/Acrylic groups through a specially created questionnaire of five questions with a five‐point Likert scale of possible answers (0 = never; 1 = rarely; 2 = occasionally; 3 = often; and 4 = very often). Results After 12 months, intergroup comparison with Mann–Whitney U Test related to Q2 (p = 0.193), Q3 (p = 0.960), Q4 (p = 0.317), Q5 (p = 1.000) patient satisfactions indicated that there was no significant difference between the two groups (Vertex/Acrylic), except Q1 (p = 0.010) question, Vertex group was more satisfied. The results regarding the patients of both groups (Vertex/Acrylic) showed that after 12 months of wearing the denture, the satisfaction level regarding to all questions increased, except Q5‐question for Vertex group, where the difference was not significant due to the already achieved maximum satisfaction at zero time. Conclusion Based on the findings of this clinical study, it can be concluded that higher satisfaction is seen in patients rehabilitated with VertexThermosens dentures than with conventional rigid acrylic dentures.

Although the introduction of dental implants made it possible to replace conventional dentures with implant-retained dentures, according to studies, prosthodontic treatment with complete dentures (CD) is still one of the most suitable methods for rehabilitation of edentulous patients considering their health and socioeconomic status (Oweis et al., 2022;Soboleva & Rogovska, 2022).Treatment with CD exerts an impact on the quality of oral health, which also affects the quality of life (QoL) (Limpuangthip et al., 2019).
The patient observation and satisfaction are as important indicators as clinical ones and can impact the success of the treatment plan of edentulous patients (Albaker, 2013).Considering the adaptive ability of patients with dentures is different, the comfort of patients with dentures depends to a large extent on the psychological factor.Some of the complaints coming from patients, even when the dentures meet all the clinical and technical conditions, is the inability to eat well and the poor stability of the dentures.
Numerous factors impact patient satisfaction with CD, such as age, gender, level of education, patient expectation of dentures, psychological characteristics of patients, patient-dentist communication issues, quality of dentures (retention, stability, fit, vertical dimension, occlusion, different denture base material, denture manufacturing technique and protocol, arrangement of teeth, and esthetics), occlusal factors, class of alveolar ridge, saliva (viscous or serous), the size of the tongue and xerostomia (Alves et al., 2018;Budală et al., 2021;Celebic et al., 2003;Darwish, 2021;Hatim & Mohi Al-Deen, 2014;Limpuangthip et al., 2019;Marchini, 2014;Musavi et al., 2018;Ohara et al., 2022;Oweis et al., 2022;Possebon et al., 2020;Soboleva & Rogovska, 2022).Several questionnaires have been created to assess the correlation between the above factors and oral health with QoL.One of the most widely used questionnaire instrument to measure the impact of oral health on the QoL is Oral Health Impact Profile-49 (OHIP-49).To shorten the time for filling out the questionnaire, it was compiled a shorter version of OHIP, the OHIP-14, which is considered quite suitable and is available in several languages in Europe and worldwide (Bimbashi et al., 2012;Kołciuk & Godlewski, 2015;Montero-Martín et al., 2009;Rener-Sitar et al., 2008).Moreover, for edentulous patients another specific version of the OHIP was prepared, such as OHIP Edentulous (OHIP-EDENT) (Allen & Locker, 2002).In addition, the use of OHIP-7T and OHIP-5 with a lesser number of questions made it possible to assess oral health related to QoL (OHRQoL) in almost any dimension by simplifying the procedure, therefore making it less annoying for the patient, and a comprehensive OHRQoL assessment with a good informative result has been achieved (Naik et al., 2016;Teng et al., 2020).The satisfaction regarding CD, that the patients are usually asked to assess include difficulties in chewing food, speech problems, ability to taste food or feeling a bad taste, comfortability, and esthetically.
The satisfaction level of CD patients is highly dependent on the dentist-patient relationship.The advice given to the patient should be easy to understand depending on the patient's age and intellectual level.Factors such as the patient's personality and the dentist-patient interaction can greatly affect the success of prosthetic treatment with CD.However, the nature of denture acceptance is highly subjective.In many cases, the dentist may have difficulty persuading the patient to wear dentures that are well-fitted due to psychological factors (Pasad et al., 2021).Anxiety is a factor that greatly affects CD satisfaction of edentulous patients (Shrivastava et al., 2012).
According to studies, to improve the quality of dentures modifications have been made to denture base materials, including conventional acrylic resins, high-impact resins, glass fiber-reinforced resins, and metal-reinforced resins (Lamfon & Hamouda, 2019).
These modifications have been made to improve the QoL of patient's denture wearers as much as possible.Rigid acrylic dentures do not always meet functional and esthetic requirements.As most patients wearing CD are elderly and in poor health, they complain of injuries caused by the rigid base of the dentures, so perfect materials are always required.According to the studies thermoplastic materials are a better choice for dentures, taking into account their flexible properties and resistance to breakage (Hazari et al., 2015;Im & Am, 2018).The disadvantage of thermoplastic dentures is the fact that over time their surface becomes rougher and loses its luster, which makes staining and discoloration easier.They are also a suitable place for buildup of plaque and growing bacteria if the wearer doesn't maintain proper oral hygiene.
Although various studies have been done on the esthetic, retention, masticatory performance, and comfort of dentures, objective studies that evaluate and compare patient satisfaction with conventional acrylic CD dentures and thermoplastic VertexThermosens CD are lacking.Therefore, the aim of this study was to assess and compare the impact of these two types of denture materials on the QoL of patients in the 12 months of denture use.

| METHODS
This randomized study was carried out at the Department of Prosthetics "Alma Mater Europaea Campus College" "REZONANCA" in Prishtina, Kosovo with prior approval from the Ethical Committee

| Statistical analysis
The data obtained with the research were processed in SPSS software package, version 22.0 for Windows, and presented in tables and figures.The qualitative series were processed by determining the coefficient of relations, proportions, and rates, and were shown as absolute and relative numbers.Quantitative series were analyzed with measures of central tendency (mean, median, minimum, and maximum values, interactive ranks), as well as by dispersion measures (standard deviation).Two independent numerical variables with nonnormal distribution of frequencies were compared with the Mann-Whitney U test.The analysis of two and more dependent variables with nonnormal distribution was made with Wilcoxon signed rank test.
A two-sided analysis with a significance level of p < 0.05 was used to determine the statistical significance.

| RESULTS
The analysis of general characteristics referred to the distribution of patients from both groups according to gender and age.
Gender: In each of the two groups (Vertex/Acrylic), an analysis was made of the distribution of patients according to gender (Figure 1).The presence of men and women in groups with different types of CD (Vertex/Acrylic) was equal for 12 (40%) versus 18 (60%) respectively with a gender ratio of 0.66:1.The percentage differences of the presence of men compared to women in both groups were insignificant (difference test: 6%, 95% CI: [−12.83 to 24.63]); χ² = 0.416; df = 1; p = 0.519).1).
To see the internal consistency of the block of five questions about patient satisfaction, a reliability analysis was made of the answers received at both times (zero and 12 months) by calculating the coefficient Cronbach's α (Table 2).The results showed that the coefficient Cronbach's α is 0.773 versus 0.707 respectively, indicating satisfactory reliability of received answers from patients (Table 2).
A descriptive analysis was made according to the category of answers received to each of the five questions about patient satisfactions and it was observed that (Tables 3, 4 and Figures 2-6).
F I G U R E 1 Analysis of Vertex/Acrylic groups according to gender.
T A B L E 1 Analysis of Vertex/Acrylic groups according to age.None of the patients in the both groups answered that they "never" had a problem with chewing.After 12 months, this problem had "never" versus "rarely" 11 (36.7%)versus 12 (40%) of the patients with Vertex and 3 (10%) versus 12 (40%) of the one with Acrylic respectively (Tables 3, 4 and Figure 2).
Q4-feeling of bad taste: in zero time, the majority of patients from both groups (Vertex/Acrylic) answered-7 (23,3%) that they "never" had feeling of bad taste.This sensation at zero time was "rare" in 21 (70%) of the patients with Vertex and 18 (60%) of those with Acrylic.After 12 months, without a feeling of bad taste were 29 (96.7%) of the patients with Vertex and all 30 (100%) patients with acrylic (Tables 3, 4 and Figure 5).
After 12 months, all 30 (100%) patients from both groups "never" had this feeling.
F I G U R E 3 Patient related "Pain/discomfort" (Q2).
F I G U R E 4 Patient satisfaction related to "Awareness/concern about oral problems" (Q3).
F I G U R E 5 Patient satisfactions related to "Feeling of bad taste" (Q4).
The results regarding the patients of both groups (Vertex/Acrylic) showed that after 12 months of wearing the denture, the satisfaction level regarding to all questions increased, except Q5-question for Vertex group, where the difference was not significant due to the already achieved maximum satisfaction at zero time (Tables 3, 4 and Figure 6).Nevertheless, related to Q1 patient satisfactions a statistically significant difference in mean satisfaction score was found at Vertex group (Z = −2.575;p = 0.010) (Tables 3, 4 and Figures 3-6).

| DISCUSSION
Determining the factors that influence the satisfaction of patient denture wearers is of great importance, considering that it also affects overall health and QoL of the patient.Objective professional viewpoints do not always correspond to patient satisfaction.
Therefore, this study focused on patient evaluation dentures from the patient's viewpoints by answering five questions, the responses to which were rated on 0-4 scale, from never to very often (0-never, 1-rarely, 2-occasionally, 3-often, 4-very often).
Improvement questionnaire score in both groups after 12 months of denture wearing reflects improved patient satisfaction.
Similar findings have been reported by other authors, although by using other questionnaire instruments (Čelebić & Knezović-Zlatarić, 2003;Km et al., 2021;Musavi et al., 2018;Mushtaha et al., 2020;Nazeer et al., 2016).In addition, improvement was observed also in clinical objective status.In the first month of dentures, patients had lesions in the form of minor injuries which were healed after denture corrections with systematic appointments.
By comparing the two groups, statistically there was an insignificant difference in patient satisfaction after 1 week of denture insertion with regard to questions related to the "difficulties chewing food" (Q1), "awareness/concern about the oral problems" (Q3), "feeling bad taste" (Q4), "impaired daily activities" (Q5).Whereas, in regard to the question related to "pain/discomfort" (Q2) the VertexThermosens dentures group was significantly more satisfied than conventional acrylic group.This may be due to thinner, lighter layer and small flexibility of thermoplastic VertexThermosens denture base material.
Interestingly, after 12 months of denture insertion, conventional acrylic group showed improvement of satisfaction in the question related to "pain/discomfort" (Q2), although VertexThermosens group had higher percentage of responses in 0 and 1 scale than the acrylic group, which had more responses in 1 and 2 scale.The ability of denture base materials to withstand force of mastication depends on flexural strength, which is higher in VertexThermosens denture base materials, and it simulates the stress types that are applied on denture base during mastication, which cause less injury (Mohsin et al., 2017).The improvement of acrylic denture wearers related to "pain/discomfort" may have occurred because the base of the acrylic dentures is more rigid and has led to more noticeable injury of the oral mucosa, while with further adaptation of the oral mucosa, the injury has been reduced.Moreover, the higher level of patient satisfaction can also be attributed to regular invitations for visits, which makes the patient feel better treated.Similar results were reported by other studies (Ellis et al., 2007;John et al., 2004;Kołciuk & Godlewski, 2015;Mushtaha et al., 2020).
In the present study, after 12 months, intergroup comparison with Mann-Whitney U test related to Q2, Q3, Q4, and Q5 satisfaction indicated that there was no significant difference between the groups.Related to the "difficulties of chewing food" F G U 6 Patient satisfaction related to "Impaired daily activities" (Q5).
Fayad et al. in their study reported a significant increase of the bite force after 6 months of denture wearing in the thermoplastic dentures group compared to conventional acrylic dentures group.
However, at the time of denture insertion, these two groups did not show any significant difference in bite force.In addition, bite force was increased considerably after 6 months of denture use in both groups (Fayad et al., 2018), which corroborate the findings of the present study and are in agreement with the results of other studies as well (Borie et al., 2014;Km et al., 2021).
According to a study (Hazari et al., 2015), a statistically significant number of patients found flexible dentures to be more satisfying and comfortable than conventional dentures.These findings were in accordance with other studies (Akinyamoju et al., 2017;Dhiman & Chowdhury, 2009;Goiato et al., 2010).In present study, even though there were no significant differences between the groups, it was validated that from the start of the denture insertion, the patient's satisfaction scored higher in the evaluation scale for the VertexThermosens group.The use of VertexThermosens CD is an effective treatment from the viewpoint of patient preference.Most patients seem to have more comfortable dentures and better chewing ability with this denture base material.
The limitations of the current study are that the observations were made over a short period of time (12 months) and patients who had CD insertions for the first time were not distinguished from patients who already had them.Further studies with a longer observation period and a larger sample size can be conducted to reach a more definitive conclusion whether the VertexThermosens or conventional rigid acrylic dentures are a better choice.

| CONCLUSION
No significant statistical difference in patient satisfactions was observed after rehabilitation with thermoplastic VertexThermosens and conventional rigid acrylic dentures at the end of 12 months observation period, with the exception of the "difficulties chewing food" question whereby VertexThermosens dentures group was significantly more satisfied than conventional Acrylic group.There was a significant improvement in patients' satisfaction with dentures in both groups within the period 0-12 months.

(
AD-3063/21,18.06.2021).A comparative clinical trial involved 60 participants aged between 45 and 80 with representation of both sexes.The patients were randomly divided in two groups: the first group (experimental group)-30 participants had CDs from VertexThermosens base material; the second group (control group)-30 participants had CDs from Convectional Rigid Acrylic base material.The exclusion criteria were the following: radiation, immunosuppressive therapy, bone metabolic diseases, allergy in denture base material.Patient satisfactions with the dentures were assessed in each of the two Vertex/Acrylic groups through the OHIP5 questionnaire with a five-point Likert scale of possible answers (0 = never; 1 = rarely; 2 = occasionally; 3 = often; 4 = very often).The questions covered the following aspects: (a) Q1-chewing difficulties (Have you had difficulty chewing any foods because of problems with your teeth, mouth, dentures or jaw?);(b) Q2-pain/discomfort (Have you had painful aching in your mouth?);(c) Q3-awareness/concern about mouth problems (Have you felt uncomfortable about the appearance of your teeth, mouth dentures or jaws?);(d) Q4-feeling of bad taste (Have you felt that there has been less flavor in your food because of problems with your teeth, mouth, dentures or jaws?); and (e) Q5difficulties in performing daily activities due to a problem with the mouth (Have you had difficulty doing your usual jobs because of problems with your teeth, mouth, dentures, or jaws?).A lower total score indicated greater patient satisfaction.The questionnaire was applied two times, at the first week of denture insertion (zero) and after 12 months of denture insertion.
Internal consistency of patient satisfaction in two time points.OHIP-5 values of the respective dimensions in relation to time: First week and after 12 months of Vertex and Acrylic denture use.Comparison of the OHIP-5 values of the respective dimensions in relation to time: First week and after 12 months of Vertex and Acrylic denture use.