Introduction

The rehabilitation of the edentulous mouth provides one of the most perplexing challenges in dentistry. Too often the challenge passes unrecognized and the individuality of the patient is submerged in an arbitrary blanket of dental empiricism. Denture wearers are probably one of the largest underserved dental patient- groups. A significant number of these patients have dentures with diminished or poor function for a variety of reasons. Everywhere in the world, a large part of the population has an incomplete, but still functional, dentition. Many patients function satisfactorily with a shortened dental arch without the need for treatment (1). Nevertheless, restoring oral function in its complete sense, including appearance, is often necessary and often demanded by patients.

With advances in dental research, technology, and education, many older people in industrialized countries are retaining more of their natural teeth for longer than their predecessors (2). Yet more than 40% of adults over age 65, as well as many younger adults, are still edentulous and in need of complete denture therapy. Although the placement of implants to reestablish lost function and esthetics has increased substantially in recent years, implants may not be a solution for a significant number of adults because of medical, physiological, psychological, or financial constraints (3). Therefore, conventional removable denture therapy will remain an important and essential tool for the restoration of the oral function of edentulous and partially edentulous adults in future.

Dissatisfaction with removable dentures is commonly reported by patients, with 25% of denture wearers having severe problems with their dentures (4). Pain and denture looseness are among the frequent reasons for complaints, with many denture wearers reporting difficulties during eating and speaking. Similarly, dissatisfaction with removable partial dentures (RPD) was related to chewing difficulties, esthetics, and speech (5, 6). Despite the large volume of literature regarding patient satisfaction with removable denture therapy, there is little consensus among investigators with regard to the most reliable predictors of denture success. In a Dutch follow-up study(7) conducted five years after provision of dentures, well-fitting and functioning dentures, the absence of pain, and a socially acceptable appearance were found to have contributed most to patient satisfaction. Similarly, in a Japanese study (8), there was a highly significant association between aspects of denture quality and patient perceptions of denture comfort and the ability to masticate. Complete denture usage patterns also were found to be positively associated with the accuracy of inter-maxillary relations (9). On the other hand, Vervoorn et al. (10) reported no significant association between denture success and denture quality, or between denture complaints and denture quality. They suggested other aspects of care, perhaps dentist– patient interaction, may be mostly responsible for denture success.

It has been suggested the patient’s personality and his/her relationship with the dentist play a substantial role in overall success, and psychological attributes are as important for success as a patient’s anatomical features as well as the dentist’s skill in providing complete denture therapy (11). Supporting this view, an inverse association between the quality of centric relation and patient satisfaction with dentures has been reported (12, 13) and another investigator reported the better quality of the dentures resulted in greater dissatisfaction by the patient (14). No correlation has been shown with regards to patient characteristics and satisfaction with dentures (15).

It has been contended patient satisfaction with complete dentures is influenced by a complex of psychological, biological, anatomic, and constructional factors. For example, the dilemma of providing dentures to patients with unrealistic expectations of dental care has been discussed (16). According to Albino et al. (17) a patient’s pretreatment expectations may influence treatment outcomes, and treatment failures may result from mismatched perceptions and expectations of the patient and the dentist. Because individual patients have unique experiences, expectations, emotions, adaptive abilities, and physical attributes, the task of predicting denture success is complex. Often, there are factors beyond the dentist’s control that affect a patient’s ability to achieve a successful denture outcome. Numerous factors associated with aging i.e. xerostomia, tissue fragility, muscle weakness, osteoporosis, arthritis, and depression have been reported as possible causes for denture failure. Experience with denture usage is another determinant of patients’ acceptance of their new dentures (4, 18).

The purpose of this investigation was to analyze the relative importance of objectively assessed denture quality among a number of other patient factors that could affect patient satisfaction with removable prostheses.

Materials and Methods

The study sample comprised all patients who were treated with removable dentures at the Govt. dental college & hospital, Jaipur, India over a period of two years. Patients were treated by postgraduate and undergraduate dental students under the supervision of specialists and experienced faculty members. A conventional protocol for construction of removable dentures was followed that included the following elements:

• Preliminary impressions for fabrication of custom trays

• Border molding

• Final impressions with polyvinyl siloxane elastomeric material

• Routine use of centric relation maxilla-mandibular jaw relationship except when stable tooth contacts were present

• Mounting of casts in a semi-adjustable articulator using a facebow transfer and an inter-occlusal record (in most cases).

Dentures were tried in the mouth at the wax setup stage and patients were allowed to return for adjustment after insertion. Recalls for the purpose of this study were arranged by telephone contact, and the patient was requested to return for examination.

The “Patient Denture Satisfaction Questionnaire” used was a modification of the one developed by Bolender et al.(19) Each participant had his/ her personal data recorded, including age, sex, number of years of denture experience, and educational level. A satisfaction score was calculated based on the patient’s rating of different aspects of perceived denture quality, including appearance, retention, ability to chew, ability to speak, and overall comfort. Rating categories were satisfactory, sort of satisfactory, unsatisfactory, and completely unsatisfactory, with allocated numerical scores of 4, 3, 2, and 1 respectively. The final score was obtained by summation of individual scores.

All objective quality evaluations were performed by one examiner using the portion of the CDA (California Dental Association) system specifically designed for follow-up of removable prostheses (20). The CDA guidelines assess dentures in terms of indication, esthetics, materials used, extensions, design, occlusion, function, stability, and retention. Following evaluation, the denture is rated according to one of four possibilities: range of excellence, range of acceptability, replace or correct for prevention, and replace immediately. The first two ratings were considered acceptable, while the last two ratings were considered unacceptable. Intra-examiner agreement was assessed using Cohen’s kappa, with K being 0.809. The relationship between denture quality (independent variables) and satisfaction was analyzed using the Chi-square test.

Results

Of a total of 415 patients, 64 (15.42%) were non-contactable, 4 (0.96%) were deceased, 23 (5.54%) had moved out of town, 11 (2.65%) were ill and unable to attend a recall, and 7 (1.69%) had already changed their dental treatment plan. Of the 306 remaining people who were personally contacted, 185 patients attended for re-evaluation, yielding an adjusted response rate of 60.45%. The typical patient recalled was 67 years old and was wearing at least one removable denture constructed about more than a year earlier. The age range was 43 to 91 years and 78.37% (n=178) of the patients were male. About 30.8% of the sample was illiterate, 43.78% had less than a high school education, and 25.40% had completed some college and/or postgraduate education. The removable dentures examined were the first for 71% of the sample.

Denture Quality

Table 1 shows the distribution of the types of removable dentures and their quality ratings. Fifty seven percent of the dentures were classified as satisfactory in terms of quality, while 43% were not and needed to be replaced. Reasons for classifying dentures as unacceptable included the following:

• Poor esthetics

• Over- or underextension

• An inappropriate peripheral seal

• Presence of occlusal interferences

• An inadequate adaptation/Improper stability

• An unhygienic design

• Damage to oral structures

• Inadequate retention.

In general, removable dentures fabricated by junior students were less satisfactory with regard to quality than those made by senior students and faculty members (Table 2).

Figure 1

Table (1): Percentage distribution (and numbers) of types of removable dentures according to CDA quality classification

Figure 2

Table (2): Quality evaluation of removable dentures by student courses

Patient Satisfaction

Denture Quality and Patient Satisfaction

Results showed a strong association between the overall CDA rating and the satisfaction index (Table 4). Of all acceptable removable dentures according to objective assessment, 95% were reported as satisfactory. Only 49.5% of the unacceptable removable dentures were reported as unsatisfactory.

Figure 3

Table (3): Quality of removable dentures and denture usage

Figure 4

Table (4): Patient’s satisfaction and denture quality

The relationships between patients’ satisfaction and patients’ age, denture experience, and educational level are shown in Tables 5–7.

Figure 5

Table (5): Rate of satisfaction of patients with removable dentures by denture experience

Figure 6

Table (6): Patient satisfaction with removable dentures by patient age

Figure 7

Table (7): Rate of satisfaction of patients with removable dentures by patients’ educational level

Discussion

The great majority of the recalled patients were satisfied with their prostheses. However, 21.47% were not satisfied with their removable dentures, which correspond to the dissatisfaction rate (15% and 26%) reported by van Waas (12) and Frank et al (4) respectively. In general, dissatisfaction or the nonuse of all types of removable dentures has been shown to range between 3 and 40% (18). Age appeared to have no significant influence on predicting patient satisfaction, a finding that is widely supported by previous studies (12, 18, 21, 22).

Patients with previous denture experience would be expected to be more satisfied. In this study, denture experience did not show significant association with patient satisfaction, although patients with previous denture experience were slightly more satisfied. As patients acquire additional sets of dentures, their neuromuscular control becomes more highly developed. Their ability to stabilize new dentures in the mouth may be relearned more quickly than is possible for patients who undergo this process for the first time. Educational level correlated significantly with patients’ satisfaction. Indeed, it was the only patient factor in this study that positively affected the patient’s attitude towards their denture.

Bader and Shugars had stated the “quality of a service was defined more by its technical perfection than its success in resolving the patient’s problem” (23). Insofar as this statement appears to draw a distinction between patient needs and technical excellence, it fails to connect the interplay that might exist between the two. The present finding of a significant association between technical qualities, as assessed through the CDA system and patient satisfaction confirms the relevance of technical quality to subjectively perceived outcome. As such, it refutes the view that, in evaluating quality of service, technical quality and satisfaction are mutually exclusive. Indeed, research has shown clear associations between health-related quality of life measures and clinical oral indicators (24)

Furthermore, the present findings are noteworthy in view of the general observation that the disparity in patient and provider judgments of treatment quality increases when patient satisfaction is low. However, this finding may be explained by the fact evaluation of treatment quality was not independently performed.

Despite the generally significant relationship between patient satisfaction and quality of dentures, one should not ignore the small number of patients who did not conform to such a relationship. Those patients who were not satisfied with objectively rated acceptable dentures may represent the most difficult patients to treat. The reason for their dissatisfaction could be explained by poor adaptative abilities and/or psychological reasons. Conversely, patients who are satisfied with unacceptable dentures are regarded as having better adaptative and tolerance levels.

The validity of the satisfaction measure warrants discussion since it relies on questionnaire data. However, the credibility of the main result is strengthened by the fact the result was stable through various questions. The issue of the relation between patient satisfaction and technical quality of the treatment at various levels of these parameters somehow remains far from resolved and should be the subject of future studies. Whether patient dissatisfaction is directly caused by a perception that inadequacies of the prosthetic appliance are giving rise to their maladaptation remains to be investigated. In other words, factors may depend on the psychological profile of the patient. An alternative explanation is communication might have been better between the dentist and the patient with good technical quality that led to improved satisfaction. Settling of this issue would require more intricate studies using observations of the patient–provider situation.

Conclusions

In conclusion, the present results underscore the importance of high technical quality as a cornerstone of prosthetic dentistry, and particularly so insofar as patient satisfaction and quality of life are concerned. Further support for this conclusion was obtained by way of the large number of patients who expressed their great satisfaction with their treatment during the questionnaire and interview session. They claimed treatment had influenced their quality of life in a positive way, and while this is clearly qualitative, it reinforces the view that prosthodontic rehabilitation has the potential to positively impact patients’ quality of life. Achieving patients’ satisfaction after the delivery of removable denture is a challenging task in prosthetic dentistry. Improving the quality of removable dentures will improve but not ensure patient satisfaction. The patients’ acceptance of removable dentures is related to several unknown factors and cannot be fully predicted from quality standards of those dentures.