Some clinical investigations on retention forces of maxillary complete dentures with the use of denture fixatives

Effect of denture adhesives on masticatory performance: Multicenter randomized controlled trial

PURPOSE

The purpose of this study is to investigate the effects of denture adhesives on masticatory performance via a 10-center, parallel, randomized, controlled trial of complete denture wearers in Japan.

METHODS

The trial was conducted between September 2013 and October 2016. The inclusion criteria were complete edentulism, willingness to undergo new complete denture treatment, and willingness to return for recall treatment. The exclusion criteria were age 90 years or older, presence of severe systemic illness, inability to understand the questionnaires, wearing metal base complete dentures, denture adhesive user, wearing prosthetics for maxillofacial defects, wearing complete dentures with tissue conditioners, and severe xerostomia. Randomization of the powder-type denture adhesive (powder), cream-type denture adhesive (cream), and control (saline) groups was performed using a sealed envelope system. Masticatory performance was measured using color-changeable chewing gum. Intervention blinding was not feasible.

RESULTS

Sixty-seven control, 69 powder, and 64 cream participants are analyzed using the intention-to-treat principle. The participants in all groups show significantly improved masticatory performance at post-intervention (paired t-test with Bonferroni correction P < 0.0001). However, no significant difference in masticatory performance is detected among the three groups (one-way analysis of variance). A significant negative correlation between pre- and post-changes in masticatory performance and intraoral condition scores is observed (Pearson's correlation coefficient, P < 0.0001).

CONCLUSIONS

Although denture adhesives improved the masticatory performance of complete denture wearers, their clinical effects are comparable to those of saline solution. The use of denture adhesives is more effective in complete denture wearers with unsatisfactory intraoral conditions.

Multivariate analysis reveals oral health-related quality of life of complete denture wearers with denture adhesives: a multicenter randomized controlled trial

Purpose To investigate the difference in improvement of oral health-related quality of life (OHR-QoL) depending on the oral and denture conditions of a complete denture wearer when using a cream or powder type denture adhesive in a 10-center parallel randomized clinical trial.Methods Two hundred edentulous subjects who wore complete dentures were allocated to each of the three groups according to denture adhesive type: cream, powder, and control (saline solution). The materials were applied to the mucosal surface of the dentures for 4 days, and baseline data and data after the intervention were collected. OHR-QoL was assessed using the Japanese version of the modified Oral Health Impact Profile for Edentulous Patients (OHIP-EDENT-J) scale for outcome. Multivariate analysis was used to investigate improvements in OHR-QoL according to participant characteristics among complete denture wearers using these materials.Results OHIP-EDENT-J scores were significantly decreased in all groups after the intervention (p < 0.05); however, there were no statistically significant differences among the groups. Multiple logistic regression analysis revealed a significant association between the vertical height of the maxillary and mandibular alveolar ridge and OHIP-EDENT-J scores in the cream-type denture adhesive group. In contrast, there were no significant association between participant characteristics and OHIP-EDENT-J scores in the powder-type adhesive and control groups.Conclusions The use of denture adhesives could improve OHR-QoL for complete denture wearers. The cream-type denture adhesives may be expected to improve OHR-QoL in patients with poor residual ridge conditions compared with patients with good residual ridge conditions.

Subjective Evaluation of Denture Adhesives: A Multicenter Randomized Controlled Trial

INTRODUCTION

Many reports show that denture adhesives improve the retention and stability of dentures. However, few randomized controlled trials have examined the effects of denture adhesives.

OBJECTIVE

This 10-center randomized controlled trial with parallel groups involving 200 edentulous patients wearing complete dentures aimed to evaluate the effects of short-term use of cream and powder denture adhesives.

METHODS

Patients were allocated into 2 cream- and powder-type adhesive groups and 1 control group. Intervention groups were treated with the 2 adhesives (1 each), and the control group received saline solution. Adhesive or control was applied to the denture-mucosal surface for 4 d, and data at baseline and after day 4 of intervention (i.e., 8 meals) were obtained. Patient satisfaction was evaluated with a 100-mm visual analog scale. Oral health-related quality of life was measured with the Japanese version of the Oral Health Impact Profile for Edentulous Patients. Perceived chewing ability was evaluated by a questionnaire regarding ease of chewing and swallowing food. Between-group comparisons were performed with Kruskal-Wallis tests with the Mann-Whitney U test adjusted by Bonferroni correction. Within-group comparisons of pre- and postintervention measurements were performed with the Wilcoxon signed-rank test. Intention-to-treat analysis was also performed.

RESULTS

Between-group comparisons showed no significant differences for general satisfaction or Oral Health Impact Profile for Edentulous Patients. However, significant differences in satisfaction with various denture functions with cream- and powder-type adhesives were seen in pre- and postintervention comparisons (P < 0.05). Significant differences were also observed for perceived chewing ability of hard foods (P < 0.05).

CONCLUSION

These results suggest that although denture adhesives do not invariably improve denture function, they do affect subjective evaluations and possibly chewing of hard foods. Therefore, the effects of denture adhesive use are insufficient to resolve any fundamental dissatisfaction with dentures ( ClinicalTrials.gov NCT01712802 ).

KNOWLEDGE TRANSFER STATEMENT

The results of this study suggest that denture adhesives should be applied under certain conditions; however, an appropriate diagnosis is important before application. These practice-based data provide information to establish evidence-based guidelines for applying denture adhesives.

Influence of the use of complete denture adhesives on microbial adhesion and biofilm formation by single- and mixed-species

Objectives

To verify whether the Ultra Corega Cream and Corega Strip Denture Adhesive adhesives interfere in the microbial adhesion and biofilm formation by Candida albicans and Lactobacillus casei in single- and mixed-species settings, and observe whether synergistic or antagonistic relationships between these species occur.

Methods

Specimens made from heat-polymerized acrylic resin (Lucitone 550) were fabricated (n = 144) with a circular shape and standardized roughness (3.0 μm ±0.3 Ra) and were divided into three groups: Without Adhesive (WA), with Ultra Corega Cream adhesive (CA) and Corega Strips adhesive (SA). These groups were divided into three subgroups each: C. albicans single-species, L. casei single-species and C. albicans with L. casei (mixed-species). Microbial adhesion and biofilm formation assays were performed in duplicate at four distinct experimental times (n = 8 per experimental condition). The amount of each microorganism on the surfaces of the specimens was observed by counting of the Colony Forming Units (CFU) per substrate. Additional specimens were characterized by Scanning Electron Microscopy (SEM), with 18 specimens being used in this analysis (n = 18), 2 per experimental condition (n = 2). Two-way ANOVA and Tukey’s test for multiple comparisons were employed, using α≤0.05.

Results

L. casei (mixed-species) adhered more on the WA substrate than the CA, while C. albicans (single- and mixed-species) adhered more on the SA. C. albicans, both single- and mixed-species adhered more than the L. casei (single- and mixed-species), regardless of the substrate. L. casei (single-species) formed more biofilm on the WA, but in its mixed cultivation, it had no difference of growth among the tested situations. C. albicans (single- and mixed-species) formed more biofilm on the SA than the CA, and the fungus formed more biofilm when compared to L. casei. In general, whenever a species was compared in its single- and mixed-species situation, no statistically significant difference was observed. SEM of biofilm formation assays demonstrated that L. casei single-species WA formed more biofilm than when the adhesives tested were used, and C. albicans (both single- and mixed-species) formed more biofilm on the SA than on the CA.

Conclusions

(1) The two denture adhesives tested increased the adhesion of C. albicans but not of L. casei; (2) biofilm formation by C. albicans (single- and mixed-species) was increased on the SA; (3) Relations of synergism or antagonism was not observed between the two microorganisms studied.

A comparative analysis of salivary factors and maxillary denture retention in different arch forms: An in vivo study

Aims

This study aims to find the effect of change in different salivary factors before and after complete denture insertion and to measure the maxillary denture retention in different arch forms.

Materials and Methods

Thirty completely edentulous individuals (10 each of square, tapered, and ovoid arch form of maxilla) belonging to the age group of 40-70 years were selected. Salivary factors (flow, density, pH, viscosity, and total protein) were evaluated before and after denture insertion. Retention of maxillary denture was measured in all the different arch forms.

Statistical Analysis

Student's independent sample's t-test was applied. The correlation was analyzed by Pearson's correlation analysis.

Results

While mean flow rate and pH of saliva increased, mean viscosity, total protein, and density of saliva decreased after maxillary complete denture insertion. A positive correlation was found between retention and total maxillary basal surface area. Retention value was found to be greatest in square type and least in tapered type.

Conclusions

Complete denture acts as a mechanical stimulant thus increasing flow rate and pH immediately after complete denture insertion. Density, total protein, and viscosity of saliva decreased after complete denture insertion which may be due to increase in water content of saliva. The retention of maxillary complete denture does not seem to depend on the rate of change of the salivary factors, before and after complete denture insertion. Total basal surface area and maxillary denture retention values were highest in square arch form and least in tapered arch form.

Antimicrobial activity of denture adhesive associated with Equisetum giganteum- and Punica granatum-enriched fractions against Candida albicans biofilms on acrylic resin surfaces

Candida biofilms adhere to the internal surface of removable dentures, which is an etiological factor in the pathogenesis of denture stomatitis (DS). Adhesive materials are used at the base of maxillary complete dentures to improve their retention and chewing qualities. This article reports the antimicrobial activity of the enriched fractions of Equisetum giganteum and Punica granatum incorporated into a denture adhesive against C. albicans biofilm. The biofilms were induced on the surface of heat-cured acrylic resin specimens that were previously treated with a mixture of adhesive/herb extracts. The antimicrobial activity was evaluated by CFU counts, XTT reduction, and SEM and CLSM analysis. Both herb extracts amplified the anti-biofilm action of the adhesive on the acrylic resin by up to 12 h. Therefore, when these extracts were combined with COREGA®, they played a collaborative and innovative role in biofilm control and can be considered alternatives for temporary use in the treatment and/or prevention of DS.

The effectiveness of adhesives on the retention of mandibular free end saddle partial dentures: An in vitro study

OBJECTIVES

Existing in vitro methods for testing denture adhesives do not fully replicate the complex oral geometries and environment; and in vivo methods are qualitative, prone to bias and not easily reproducible. The purpose of this study was to develop a novel, quantitative and more accurate model to test the effect of adhesives on the retentive force of mandibular free end saddle partial dentures.

METHODS

An in vitro model was developed based on an anatomically accurate cast of a clinical case. Experimentally, the amount of adhesive was varied (0.2g-1g) and the tensile force required for displacement was measured. Different commercially available adhesives were then tested at the optimum volume using the in vitro model. A 3D finite element model of the denture was used to assess how the forces to induce denture displacement varied according to the position of the force along the saddle length.

RESULTS

The mass of adhesive was found to significantly alter retention forces, with 0.4-0.7g being the optimum range for this particular scenario. Use of adhesives significantly improved mandibular free end saddle partial denture retention with the worst performing adhesive increasing retention nine-fold whilst the best performing adhesive increased retention twenty three-fold. The finite element model revealed that 77% more force was required to displace the denture by positioning forces towards the mesial end of the saddle compared to the distal end.

CONCLUSIONS

An in vitro denture adhesive model was developed, which demonstrated that mass of adhesive plays a significant role in enhancing denture retention and supported the design principle of placing as few teeth as clinically necessary on the distal end of the free end saddles.

CLINICAL SIGNIFICANCE

Limiting the position of teeth on free end saddles to the mesial and mid portion of the saddle will reduce displacements caused by mastication. The movement of mandibular free end saddle partial dentures can be restricted with the use of denture adhesives. Altering the mass of adhesive used can further improve the retention of mandibular free end saddle partial dentures for patients.

Viscosity and adhesion strength of cream-type denture adhesives and mouth moisturizers

We evaluated adhesion strength to acrylic resins under various experimental conditions and viscosity of 4 cream-type denture adhesives and 2 mouth moisturizers. The viscosity was determined by a sine-wave vibro viscometer. The adhesion strength tests were performed with 2 resin plates at a universal tester. In Method A, various constant thicknesses of material layer were tested and tensile strength was measured, while in Method B a constant load was applied before measurement. Five tests were carried out for each measurement. With Method A, adhesion strength increased exponentially as the layer got thin. Effect of the material thicknesses (contribution ratio ρ=79.0%) was much larger than that of material type (ρ=15.3%). Materials with higher viscosity had greater levels of adhesion strength in Method A, whereas those with the higher viscosity had lower levels of adhesion strength in Method B. Adhesion strength was significantly affected by the experimental condition prior to applying tension.

Evidence-based guidelines for the care and maintenance of complete dentures: a publication of the American College of Prosthodontists

The current rates of edentulism have been estimated to be between 7% and 69% of the adult population internationally. In the United States, while the incidence of edentulism continues to decline, rapid population growth coupled with current economic conditions suggest that edentulism and conventional denture use will continue at current or higher numbers. Unfortunately, evidence-based guidelines for the care and maintenance of removable complete denture prostheses do not exist. In 2009, the American College of Prosthodontists (ACP) formed a task force to establish evidence-based guidelines for the care and maintenance of complete dentures. The task force comprised members of the ACP, the Academy of General Dentistry, American Dental Association (ADA) Council on Scientific Affairs, the American Dental Hygienists' Association, the National Association of Dental Laboratories, and representatives from GlaxoSmithKline Consumer Healthcare. The review process included the assessment of over 300 abstracts and selection of over 100 articles meeting inclusion criteria of this review. The task force reviewed synopses of the literature and formulated 15 evidence-based guidelines for denture care and maintenance. These guidelines were reviewed by clinical experts from the participating organizations and were published in February 2011 issue of The Journal of the American Dental Association for widespread distribution to the dental community. These guidelines reflect the views of the task force.

Subjective Assessment by Patients of the Efficiency of Two Denture Adhesive Pastes

PURPOSE

This study evaluated the subjective responses of 30 denture wearers with regard to the effectiveness of two denture adhesive pastes.

MATERIALS AND METHODS

Thirty patients responded to questions related to retention, chewing ability, taste, duration of adhesives in the mouth, and removal; comparing the use of two denture adhesives based on polymethylvinylether-maleic anhydride compounds or carboxymethyl cellulose.

RESULTS

The denture adhesive paste based on polymethylvinylether-maleic anhydride (PVM-MA) compound was rated higher (73% and 87%) than carboxymethyl cellulose (CC) adhesive paste (60% and 37%) on chewing ability and duration in the mouth (p= 0.0001 and p= 0.0001, respectively) by experienced denture wearers in both maxilla and mandible. There were no statistically significant differences between the two denture adhesive pastes on the retention of maxillary dentures, taste, and removal of the adhesive (p= 0.08, p= 0.67, and p= 0.41, respectively).

CONCLUSIONS

All subjects responded that the retention of their dentures was either a little better or much better when using either of the adhesive pastes.

The Effect of a New Denture Adhesive on Bite Force Until Denture Dislodgement

PURPOSE

Denture adhesives are used to improve the denture retention and comfort of complete denture wearers. The purpose of this investigation was to establish the effect of a new denture adhesive on maximum bite force until denture dislodgement (BFDD) after adhesive application.

MATERIALS AND METHODS

Fifteen denture-wearing patients (7 female, 8 male, mean age: 64 years) were involved in the study. The BFDD measurements were performed using a disposable gnathometer with a 1 to 10 scale. During one of the treatment sessions, the maximum BFDD with the pre-existing maxillary dentures using denture adhesive were measured. The measurements were also made at the baseline without adhesive and after the 1st, 2nd, 4th, and 6th hours following the application of the denture adhesive. The same procedure was applied to the new dentures about 2 weeks after the delivery of the dentures. The data were collected and statistically analyzed using ANOVA and Student's t-test.

RESULTS

Consistent improvement was observed in BFDD when adhesive was used for all time intervals from the baseline (mean: 1.54 units, 3.20 units) to 6 hours (mean: 3.99 units, 4.60 units) for both pre-existing dentures (p= 0.003) and new dentures (p= 0.05), respectively.

CONCLUSIONS

The results of this in vivo study suggest that the denture adhesive tested could effectively increase BFDD for up to 6 hours after application.

Complete denture success for patients and dentists

The huge prevalence of tooth decay and the gradual ageing of populations in the developed world have combined to produce a steady increase in the need for complete denture treatment. To achieve successful treatment, it is vital to consider a number of issues throughout the denture process. Before treatment even begins, the patient's motivation for denture treatment and emotional attitude towards dentures must be evaluated. Patients will thereby gain realistic expectations of what can and cannot be achieved, and dentists will understand what the patient really wants. Afterwards, the dentist must work with the patient to help achieve success in difficult areas such as neuromuscular control, mastication and speech. By learning to handle patient complaints positively, dentists can educate patients to solve their own problems in future. Finally, patients must be informed that continued success depends on regular denture maintenance at home combined with periodic consultation with the dentist.