Do traditional techniques produce better conventional complete dentures than simplified techniques? A 10-year follow-up of a randomized clinical trial

Abstract

Objectives

The use of a simplified method (S) of fabricating complete dentures has been shown to be more cost-efficient than the traditional method (T), and there are no negative consequences that detract from the cost savings in the short term. However, it is not clear whether this remains constant over a decade. The objective of this study was to clarify patients’ perspectives and determine any differences between the dentures fabricated with these two different techniques after a decade of use.

Material and methods

Edentate individuals participated in a randomized controlled clinical trial and completed a 6-month follow-up from 2001 to 2003 (T group n = 50; S group n = 54). For this 10-year follow-up, they were interviewed by telephone. The assessment included whether the denture was still in use or replaced, the condition of the dentures, patient satisfaction and oral health-related quality of life (OHRQoL). Between and within-group differences and the factors that cause deterioration of oral health-related quality of life (OHRQoL) were determined.

Results

Among 54 responders (25 T and 29 S), 14T and 21S kept the original dentures. Both groups were similar in ratings of satisfaction and OHRQoL (maxilla T: 80.0 S: 86.0, p = 0.36; mandibular; T: 66.1 S: 72.3, p = 0.48; OHRQoL T: 111.1 S: 108.5, p = 0.46). Irrespective of fabrication method, discomfort, chewing difficulty and esthetics were the factors that deteriorate OHRQoL (adjusted r = 0.76, p < 0.001).

Conclusion

The results indicate that the simplified method remains more cost-efficient than the traditional method over a 10-year period.

(IRB approval: A09-E71-12 B McGill University, trial registry: ClinicalTrial.org; NCT02289443)

Introduction

According to Health Canada, 21.7% of Canadians aged 60–79 are edentulous . Although the incidence of edentulism is decreasing in some places , regional and ageing factors still maintain the high prevalence of edentulism; thus, the worldwide population of people 65 years and older will need complete denture therapy. Along with the increase in the elderly population, elderly edentulous individuals who need complete denture treatment are expected to have more diverse systematic diseases and complex psychological conditions, as well as a lower socio-economic status. Therefore, for elderly people who have limited ability to travel or to tolerate multiple or longer dental care visits, a satisfactory result may require the use of a simplified method, rather than traditional procedures to fabricate conventional complete dentures.

In most dental schools, the traditional (T) method of denture fabrication is taught . However, after graduation, general dentists are more likely to offer their edentulous patients prostheses that are made using simplified (S) techniques . Between 2000 and 2003, we carried out a randomized clinical trial (RCT) in which we compared these two different techniques using patient- and clinician-reported outcomes and treatment-related costs. The quality of the dentures was assessed by prosthodontists who were blinded to treatment assignment and unaware of the research protocol. These results were previously published . The two groups were similar in patients’ ratings of overall satisfaction measured on 100 mm VAS and in prosthodontists’ ratings of denture quality at the 6-month follow up . The cost analysis showed that the mean total cost of the traditional (T) method was significantly more expensive (CAN$166.3) than the simplified (S) method and that clinicians spent significantly longer (90 min) on clinical procedures with the T method . These results indicated that dentures made using an S method that simplifies or eliminates some of the steps in the fabrication is the more cost-efficient and that there are no negative consequences that detract from the cost savings. Several randomized studies followed comparing these two fabrication methods; they also showed similar results in both patient-reported and clinician-based outcomes , as well as cost . Two systematic reviews concluded that the S method could replace or partly replace the T method ; they demonstrate some advantages of simplified over traditional prostheses, such as lower cost and clinical time, good chewing efficiency, and a positive effect on quality of life .

However, the follow-up period of these randomized trials was short-term and less than a year. Edentulous patients who are comfortable with their dentures rarely visit the dentist on a regular basis . Thus, it is not clear whether their satisfaction, quality of life and comfort remain stable after a longer period of time. In this study, we measured patient satisfaction and oral health-related quality of life one decade following their receipt of new dentures fabricated with two different techniques: S and T. The objective of this study was to determine patient satisfaction and oral health-related quality of life (OHRQoL), as well as any other outcomes, associated with these 10-year old dentures.

Materials and methods

Study design

This is a 10-year follow-up study of a parallel randomized controlled clinical trial (RCT) originally carried out from December 2000 and December 2002 . The follow up study was carried out from September 2012 to December 2013; includes the assessment of patient satisfaction, OHRQoL and problems associated with the dentures. Data were gathered through telephone interviews using a standardized flow sheet.

Subjects

Males and females aged 45 to 75 who participated in and completed a 6-month follow-up in the original RCT (T: 49, and S: 54; total 103 subjects) were the potential interviewees for this 10 year follow-up; all were contacted by telephone.

Interviews and blinding

Potential participants were told that the study objectives were aimed to investigate the condition of their dentures 10 years after delivery. Following this, the subjects were asked whether they were willing to participate in the interviews. According to a standardized flowchart, the interviewer then asked the questions; these included general and specific questions on health and denture problems, as well as ratings of denture satisfaction and OHRQoL ( Fig. 1 ). The participants were not told into which group they had originally been assigned, and a blinded research assistant carried out the interviews and data gathering. Participants were excluded from the analysis if they could not respond properly to the questions.

Fig. 1
Telephone Interview questionnaire.

Questionnaires

Data were gathered using four questionnaires: socio-demographic, denture history/oral health, satisfaction ratings and related items (comfort, stability, esthetics, retention, mastication, and ease of cleaning). OHRQoL measures consisted of 20 statements and responses varying from 0 to 6 on a Likert scale (OHIP-20) . The possible range between 0 and 120 was derived individually.

Analysis

Denture prognosis

The number of continuing users of the original T and S dentures at 10 years was counted and calculated in percentages using a chi-squared test. In addition, the prevalence of problems with the denture, including pain, looseness, discomfort, chewing difficulty, speaking difficulty, and unfavorable esthetics were also counted and compared by t -test.

Satisfaction

Satisfaction and OHIP-20 ratings were compared between the T and S groups by t -test. Within-group differences between the satisfaction ratings at 6-months and 10-years were also compared using the Wilcoxon signed-rank test.

OHRQoL and denture problems

The possible role of the patient’s denture problems in relation to OHRQoL was analyzed with general linear model analyses. The dependent outcome variable was measured using the OHIP-20 total score. Independent variables included responses to the specific questions about their denture problems, adjusted by group (T or S), age and gender.

Materials and methods

Study design

This is a 10-year follow-up study of a parallel randomized controlled clinical trial (RCT) originally carried out from December 2000 and December 2002 . The follow up study was carried out from September 2012 to December 2013; includes the assessment of patient satisfaction, OHRQoL and problems associated with the dentures. Data were gathered through telephone interviews using a standardized flow sheet.

Subjects

Males and females aged 45 to 75 who participated in and completed a 6-month follow-up in the original RCT (T: 49, and S: 54; total 103 subjects) were the potential interviewees for this 10 year follow-up; all were contacted by telephone.

Interviews and blinding

Potential participants were told that the study objectives were aimed to investigate the condition of their dentures 10 years after delivery. Following this, the subjects were asked whether they were willing to participate in the interviews. According to a standardized flowchart, the interviewer then asked the questions; these included general and specific questions on health and denture problems, as well as ratings of denture satisfaction and OHRQoL ( Fig. 1 ). The participants were not told into which group they had originally been assigned, and a blinded research assistant carried out the interviews and data gathering. Participants were excluded from the analysis if they could not respond properly to the questions.

Fig. 1
Telephone Interview questionnaire.

Questionnaires

Data were gathered using four questionnaires: socio-demographic, denture history/oral health, satisfaction ratings and related items (comfort, stability, esthetics, retention, mastication, and ease of cleaning). OHRQoL measures consisted of 20 statements and responses varying from 0 to 6 on a Likert scale (OHIP-20) . The possible range between 0 and 120 was derived individually.

Analysis

Denture prognosis

The number of continuing users of the original T and S dentures at 10 years was counted and calculated in percentages using a chi-squared test. In addition, the prevalence of problems with the denture, including pain, looseness, discomfort, chewing difficulty, speaking difficulty, and unfavorable esthetics were also counted and compared by t -test.

Satisfaction

Satisfaction and OHIP-20 ratings were compared between the T and S groups by t -test. Within-group differences between the satisfaction ratings at 6-months and 10-years were also compared using the Wilcoxon signed-rank test.

OHRQoL and denture problems

The possible role of the patient’s denture problems in relation to OHRQoL was analyzed with general linear model analyses. The dependent outcome variable was measured using the OHIP-20 total score. Independent variables included responses to the specific questions about their denture problems, adjusted by group (T or S), age and gender.

Results

Participant characteristics and denture prognosis at the 10-year follow-up

From September 2012 to September 2013, a research assistant attempted to contact the 103 previous RCT participants (49T and 54S) to request a telephone interview. Of those, 44 (22T and 22S) could not be reached because of unknown location or lack of response to the call. Four persons (1T and 3S) died within the 10-year period, and one T subject refused to answer the questions. As a result, 25 T (original allocation 61, follow-up rate: 41%) and 29 S (original allocation 61, follow-up rate: 47%) responded to the interview. Of those, 14 out of 25T (56%) and 21 out of 29 S (72%) were still wearing the original dentures ( p = 0.21, Fig. 2 and Table 1a ). One S participant (wearing the original denture) responded, but had difficulty hearing and could not respond to other questions; thus, she was excluded from the analysis. The groups were similar in current age, gender, edentulous classification system at baseline and 6-months. Problems at the time of the interview were similar between the groups, and 11 T (79%) and 13 S (65%) reported that their dentures are in good conditions ( p = 0.47).

Fig. 2
RCT and 10-year follow-up participant flowchart.

Table 1a
Patients’ characteristics with the original dentures at 10 years.
In use (n = 39)
Traditional (n = 14) simplified (n = 21) a p-value
Age-yrs (SD) 72.0 (5.9) 73.7 (6.2) 0.42
Gender-no. (female/male) 8/6 12/9 1.00
ACP Diagnostic criteria c -no.
I 2 2 0.75
II 2 5
III 6 6
IV 4 8
Satisfaction ratings at 6month: VAS-mm (SD)
Maxillary dentures 93.5 (9.32) 86.3 (27.7) 0.27
Mandibular dentures 75.6 (28.6) 81.9 (20.5) 0.45
Problems at the time of interview (multiple choice numbers)
Pain 1 6 0.20
Loose 3 6 0.71
Discomfort 1 3 0.64
Can’t chew 2 6 0.43
Unstable 3 7 0.70
Difficulty Speaking 0 2 0.51
Dirty 1 3 0.64
Esthetics 1 4 0.13
Other d 1 2 1.00
Do you occasionally go to the dentist or denturologiste for denture adjustments? (Y/N) 2/12 3/16 0.65
Tell me the current general condition of your denture. (Good/Bad/Getting worse) 11/0/3 13/0/7 0.47

The characteristics for those who had not kept their original dentures were also similar Table 1b ). The mean period in which the original denture was used was 7.3 years for the T group and 4.5 years for the S group ( p = 0.09). No significant difference was found in the number of reasons for changing the original dentures ( Table 1b ). Seven T (63%) and 3S (38%) reported that their dentures are in good condition ( p = 0.79). The type of dentures that replaced the original study dentures were mostly conventional; only two patients replaced them with implant retained/supported prostheses. Most of the patients paid for their new dentures themselves.

Table 1b
Patients’ characteristics with the replacement dentures at 10 years.
Renewed (n = 19)
Traditional (n = 11) Simplified (n = 8) b p-value
Age-yrs (SD) 72.5 (5.0) 68.1 (6.6) 0.12
Gender-no. (female/male) 10/1 6/2 0.55
ACP Diagnostic criteria c -no.
I 0 0 0.56
II 1 2
III 4 3
IV 6 3
Denture used year of the original (years) 7.3 (3.6) 4.5 (3.3) 0.09
Satisfaction ratings at 6month: VAS-mm (SD)
82.6 (26.3) 81.8 (18.1) 0.93
73.6 (24.8) 60.5 (29.1) 0.30
Reason for realse (multiple choice numbers)
Pain 0 1 0.35
Loose 2 0 0.52
Discomfort 1 2 0.52
Can’t chew 1 3 1.00
Unstable 2 2 0.58
Difficulty Speaking 1 0 1.00
Dirty 2 0 0.52
Esthetics 1 1 1.00
Other e 6 2 0.61
Did you go to a dentist or denturologist to adjust or repair or replace your dentures? (Y/N) 2/9 1/5 0.73
Did you get your new dentures at the same clinic?(Y/N) 0/11 0/6
How did you pay for new prostheses. (Government/Insurance/Myself) 2/9 1/5 1.00
What types of dentures are you wearing now? (Conventional/Implant removable/Implant fised)) 9/1/1 6/0/0 1.00
Tell me the current general condition of your denture. (Good/Bad/Getting worse) 7/1/2 3/1/2 0.79
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Jun 17, 2018 | Posted by in General Dentistry | Comments Off on Do traditional techniques produce better conventional complete dentures than simplified techniques? A 10-year follow-up of a randomized clinical trial

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