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doi: 10.29271/jcpsppg.2025.01.69ABSTRACT
Objective: To compare the retention of denture adhesives (powder and paste) in mandibular complete denture wearers using a dial tension gauge.
Study Design: A randomised clinical trial (RCT).
Place and Duration of the Study: Department of Prosthodontics, Khyber College of Dentistry, Peshawar, Pakistan, from November 2024 to January 2025.
Methodology: This RCT included 60 mandibular complete denture wearers who were divided into two groups; Group A received the commonly used powder denture adhesive (Protifex), while Group B received paste denture adhesive (Kelin). A dial tension gauge was used to measure denture retention in grams under standardised conditions. Retention was measured by placing a pointer in the labial frenum of the mandibular denture and measuring it by applying a vertical dislodging force: first without adhesive (which served as a baseline control value for both groups) and second after five minutes of application of denture adhesive. Data were analysed using a paired sample t-test for within-group comparison and independent t-test for between-group analysis using the SPSS version 25.
Results: Both powder and paste denture adhesives significantly improved denture retention compared to no adhesive. However, there was a significant difference in retention between the powder and paste groups (p = 0.002), with the paste group showing higher retention strength.
Conclusion: Both powder (Protifex) and paste (Kelin) denture adhesives improved retention effectively compared to no adhesive. Moreover, the paste adhesive showed slightly higher improvement. Thus, choices can be made on factors such as personal preferences and ease of use.
Key Words: Denture adhesives, Mandibular denture, Complete dentures, Powder adhesive, Paste adhesive, Retention.
INTRODUCTION
Every human has the right to enjoy their life. As the elderly edentulous population continues to rise, the need for conventional complete dentures also increases for their optimum health.1 Throughout the ages, tooth loss has affected mankind, requiring replacement by a complete or partial removable denture.2,3
Although implant-supported prosthesis has recently gained considerable attention for the treatment of edentulous arches.4 They may not always be feasible due to anatomical, physio- logical, or financial constraints. In such cases, conventional complete dentures remain the most practical treatment option.5 Adequate retention of complete dentures plays a vital role in patient satisfaction and oral function.6,7
Retention of a complete denture largely depends on factors such as the cohesive and adhesive forces of saliva, atmospheric pressure, anatomical undercuts, muscle activity, and the weight of the denture.8,9
Mandibular complete dentures generally pose greater challenges in terms of retention. This is primarily due to anatomical limitations such as movable floor of mouth, which makes achieving an effective lingual border seal difficult. Additionally, resorption of mandibular ridge often results in poor ridge height and unfavourable ridge conformation, further compromising denture retention and function.10
However, even when dentures are fabricated using correct techniques to optimise all these factors, challenges may still arise in achieving ideal retention.11 In situations such as resorbed ridges, high muscle attachment, flabby ridges, and neuromuscular incoordinations, denture adhesives help in improving retention, enhancing patient confidence during function, and increasing overall comfort and satisfaction with the prosthesis.12,13
Denture adhesives have been proven to improve the retention of dentures by forming a bond between the denture base and the supporting tissues.14 Denture adhesives are available in soluble (cream and paste) and insoluble forms (paper and tissues). Denture adhesives are applied to the intaglio surface of the dentures before insertion into the mouth.15,16 Paste and powder are commonly available adhesives. These adhesives are typically made of synthetic hydrophilic polymers. Both powder and paste adhesives belong to the water-activated, physical-type adhesive class. Upon contact with saliva, these adhesives form a gel-like layer that enhances denture retention by increasing adhesion and cohesion between the denture base and mucosal tissues. The paste adhesives are applied on a dry surface, while powder adhesives are applied on a wet surface; paste forms are commonly used in clinical practice. This mechanism reduces displacement during function and improves patient comfort.17
Denture adhesives are often used with mandibular complete dentures to improve retention when the ridge is resorbed, or fit is compromised. Among the available forms, powder and paste adhesives are commonly available in market; however, there is no clear answer on which one works better in terms of retention. To the best of the authors’ knowledge, most of the existing research on denture adhesives has either been conducted in laboratory settings or has focused on patient-reported outcomes.14 Only a few in vivo studies have assessed actual retention strength, and these have mainly involved the maxillary dentures. Clinical research on the retention of mandibular dentures remains limited.
There are multiple methods to measure the retention strength of a complete denture, such as using a gnathometre, a hydraulic pulley, a spring scale, or a digital spring scale.18 In the current study, the authors used a dial tension gauge by CYNST, which works on a spring scale mechanism that is less technique-sensitive and relatively easy to use and available in the local market.
The authors hypothesised that there is a difference in retention between powder and paste forms of denture adhesive in mandibular complete denture wearers using the dial tension gauge.
This study aimed to address gaps by comparing the retention of both powder and paste adhesives in real clinical settings, specifically with mandibular dentures, which are more prone to retention issues.
METHODOLOGY
This randomised clinical trial (RCT) was conducted at the Department of Prosthodontics, Khyber College of Dentistry, Peshawar, Pakistan, from November 2024 to January 2025.
Ethical approval was obtained from the Research Review Board of the Khyber College of Dentistry, Peshawar, Pakistan (Approval No: 36/RRB/KCD). The trial is also registered under the number ACTRN12625000099426.
Using OpenEpi, the total calculated sample size was 30, based on the mean retention values for complete dentures: 439.09 ± 168.47 for the powder group and 679.26 ± 218.26 for the paste group, with a 95% confidence interval and a 90% power test. To account for data normality, a sample size of 30 patients per group was selected.18
A convenience probability sampling technique was employed to select patients. Edentulous patients with a Class I jaw relationship and mandibular ridges classified as Grade 5 or 6 according to Atwood’s classification,10 who were receiving their first mandibular complete denture and reporting for their first follow-up visit one week after insertion, with well-fabricated dentures that have optimum extension and adequate width of flanges, proper frenal relieves and dentures that do not require any relining, were included in the study. Patients were eligible regardless of the condition of the opposing arch (e.g., natural teeth, fixed prosthesis, or complete maxillary denture), as retention was measured in isolation without occlusal contact using a dial tension gauge. Patients with neuromuscular inco- ordination, as diagnosed by a neurologist, were excluded from the study.
Patients who fulfilled the selection criteria and voluntarily agreed to participate in the trial were selected. Patients were assured of the confidentiality of their data. The patients were divided into two groups: Group A (powder denture adhesive) and Group B (paste denture adhesive) by a lottery method. Paper slips, each labelled with either Group A or Group B, were placed in a jar. Patients randomly selected a slip from the jar, and the content of the slip determined their group assignment. This lottery method ensured that each patient had an equal chance of being assigned to either group, eliminating bias. To minimise bias and ensure objective measurements, the data collection procedure involved the participation of two investigators and a principal investigator (PI). The first investigator, under the supervision of the PI, was responsible for applying the denture adhesive and ensuring proper seating of the complete denture in the patient's mouth. This setup allowed for consistent application across all participants, reducing the potential for variability. The second investigator, also under the supervision of the PI, was responsible for measuring denture retention using a spring scale. The retention was measured by placing the pointer of the gauge in the labial frenum of the mandibular denture, a vertical dislodging force was applied, and the resistance against it was measured by a dial tension gauge in grams. The second investigator was blinded to the type of adhesive applied to maintain objectivity in the measurement process. The PI oversaw the entire study and observed both investigators to ensure adherence to the protocol and prevent any potential biases.
Two commercially available denture adhesives were used: Kelin denture adhesive cream, paste form (Kelin Dental, China), and the Protifex denture adhesive powder (DFS-Diamon GmbH, Germany). These specific products were selected due to their wide availability in local markets, affordability, and frequent use in clinical practice, ensuring the study reflects real-world application and patient experience. Group A patients’ denture retention measurements without any denture adhesive application served as the control value. The powder denture adhesive was applied by the first investigator according to the manufacturer’s instructions, and the patient was instructed to maintain non- forced intercuspation (bite) for five minutes. The second investigator measured the denture retention using the dial tension gauge and recorded the results. Two additional measurements were taken after 1-minute intervals to eliminate errors. The mean of these three retention measurements was calculated to obtain a representative value for each patient. The same steps, i.e., control measurements, adhesive application, non-forced intercuspation, and retention measurements, were followed using the paste denture adhesive on patients in Group B.
Retention was measured for all participants as a baseline (without adhesive) to serve as a within-group control. For the between-group analysis, participants were randomly allocated into two intervention groups. Group A received powder adhesives (Portifex) and Group B received paste adhesives (Kelin).
The mean increase in retention strength for both products was calculated by subtracting denture retention strength without adhensive from denture retention with adhesive.
Data were analysed using the SPSS version 25. Mean and standard deviation (SD) were calculated for numerical variables such as age and retention scores of both groups (powder and paste), while frequency and percentages were calculated for categorical variables such as the gender of patients. Paired sample t-test was used for the differences before and after in each group. The independent t-test was used to compare the mean difference between the two groups. A p-value of ≤0.05 was considered significant.
RESULTS
This study included 60 patients with mandibular complete dentures, who were divided into two groups of 30 patients each. The average age for patients in Group A was 59.67 ± 9.68 years and in Group B, it was 58.63 ± 9.03 years. In Group A, 18 patients (60%) were male and 12 (40%) were female. Group B had 15 males (50%) and 15 females (50%).
The retention data before and after applying the adhesive for both groups are summarised in Table I.
The mean retention score of Group A before and after the application of denture adhesive improved, showing a mean difference of 45.05 ± 7.59 g, with a significant p-value of <0.001 as shown in Table II.
In group B, the mean retention score before and after the application of denture adhesive also improved, showing a mean difference of 58.33 ± 25.60 g with a significant p-value of <0.001, as shown in Table I.
To make a comparison between the mean retention scores of powder and paste denture adhesives, an independent sample t-test was used. Results of the test showed a statistically significant difference between the two groups (p-value 0.002). Paste denture adhesive had a better mean retention strength of 13.28 ± 48.80 g, as compared to powder denture adhesive (Table II).
DISCUSSION
This study aimed to compare the retention scores of powder and paste forms of denture adhesives in mandibular complete dentures, which may influence adhesive selection in clinical practice. Several studies have assessed denture retention through objective methods, subjective evaluations, or a combination of both. Objective measurements are preferred as they eliminate the bias of patient perception. Additionally, in vivo studies are more clinically relevant compared to in vitro studies. Therefore, the present in vivo study was conducted to objectively measure retention by determining the force required to dislodge the mandibular denture using a dial tension gauge.
The results of this study showed a statistically significant diffe- rence, with the paste denture adhesive having a mean retention strength of 13.28 ± 48.80 g greater than the powder adhesive.
Similarly, Kumar and Thombare, in their in vivo study, found that the mean denture retention strength value was 836 ± 48 g without any denture adhesive, while the retention value was 2044 ± 104 g with powder form of adhesive and 3072 ± 99 g with paste form. The results of the current study coincide with the results of the above-mentioned study. However, in contrast to the present study, they studied the upper dentures and also different brands of adhesives, which showed better retention than mandibular dentures, and this may explain the difference in mean retentions in results.19
The results of this study also coincide with the results of Kamran et al.’s study.18 In their study, paste denture adhesive improved retention more than powder denture adhesive. However, they used different commercially available denture adhesives such as Poligrip and Corega denture adhesive instead of Protifex and Kelin, and a digital spring tool was used to assess denture retention in all forms of mandibular ridges, while this study used a dial tension gauge for retention measurement of only patients with resorbed ridges (Atwood’s class 5 and 6).18
Results of another study revealed that powder denture adhesives provide superior retention compared to other types, which contradicts the present study’s results.20 This discrepancy can be due to the use of different methodologies for the assessment of retention.
Table I: Comparison of retention scores before and after denture adhesive application in Group A and Group B.|
Variables |
Before adhesive (Mean ± SD) |
After adhesive (Mean ± SD) |
Mean difference ± SD |
p-values1 |
|
Retention score (Group A) |
71.77 ± 62.94 g |
116.82 ± 79.81 g |
45.05 ± 7.59 g |
<0.001 |
|
Retention score (Group B) |
52.55 ± 32.37 g |
110.88 ± 51.11 g |
58.33 ± 25.60 g |
< 0.001 |
|
1Paired sample t-test. SD: Standard deviation. |
||||
Table II: Comparison of improvement of retention scores between powder and paste forms of the denture adhesive (Group A vs. Group B).
|
Group/comparison |
Mean difference ± SD (units) |
p-value1 |
|
Improvement in Group A |
45.05 ± 41.54g |
- |
|
Improvement in Group B |
58.33 ± 25.60g |
- |
|
Paste vs. powder (Group B vs. Group A) |
13.28 ± 48.80 |
0.002 |
|
1Paired sample t-test. SD: Standard deviation. |
||
Their study included maxillary dentures, while in the present study, mandibular dentures were included. Instead of a dial tension gauge, they used a different tool for retention measurement that consisted of one vertical adjustable metal rod supporting three horizontal adjustable metal rods with the whole assembly mounted on a wooden stand, which was connected to the maxillary denture after application of adhesive for two hours.20
This study suggests that both forms of denture adhesives improved denture retention of patients, with the paste form showing comparatively better results than the powder form of denture adhesive.
The limitations to this study included small sample size, variability in adhesive brands, study design differences, and patient-specific factors. Given these limitations, future studies should include larger sample sizes, more diverse patient groups, and longer follow-up periods to validate these findings. Additionally, research should explore factors such as patient comfort, ease of use, and cost-effectiveness to provide better clinical recommendations.
CONCLUSION
Both forms of denture adhesives improved denture retention in mandibular complete dentures. The paste form of denture adhesive showed slightly greater improvement. Therefore, patients can choose either form based on personal preference, ease of application, and individual comfort rather than performance alone.
ETHICAL APPROVAL:
Ethical approval was obtained from the Research Review Board of the Khyber College of Dentistry, Peshawar, Pakistan (Approval No: 36/RRB/KCD).
PATIENTS’ CONSENT:
Written informed consent was obtained from all patients.
COMPETING INTEREST:
The authors declared no conflict of interest.
AUTHORS’ CONTRIBUTION:
AZ: Contributed to the conception, design of the study, data acquisition, analysis, interpretation, manuscript drafting, and critical revision of the manuscript.
SNS: Supervised the study, provided continuous guidance throughout the research process, and critically revised the manuscript for important intellectual content.
AUK: Contributed to the academic environment and provided general support during the study.
All authors approved the final version of the manuscript to be published.
REFERENCES