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Denture Base (denture + base)

Distribution by Scientific Domains

Medical Sciences	73%

Terms modified by Denture Base

denture base acrylic resin

denture base adaptation

denture base material

denture base resin

Selected Abstracts

Effect of disinfection by microwave irradiation on the strength of intact and relined denture bases and the water sorption and solubility of denture base and reline materials

JOURNAL OF APPLIED POLYMER SCIENCE, Issue 1 2008
Rosangela Seiko Seó
Abstract This study evaluated the influence of microwave disinfection on the strength of intact and relined denture bases. Water sorption and solubility were also evaluated. A heat-polymerized acrylic resin (Lucitone 550) was used to construct 4-mm-thick (n = 40) and 2-mm-thick (n = 160) denture bases. Denture bases (2-mm) were relined with an autopolymerizing resin (Tokuso Rebase Fast, Ufi Gel Hard, Kooliner, or New Truliner). Specimens were divided into four groups (n = 10): without treatment, one or seven cycles of microwave disinfection (650 W for 6 min), and water storage at 37°C for 7 days. Specimens were vertically loaded (5 mm/min) until failure. Disc-shaped specimens (50 mm × 0.5 mm) were fabricated (n = 10) to evaluate water sorption and solubility. Data on maximum fracture load (N), deflection at fracture (mm), fracture energy (N mm), water sorption (%), and solubility (%) were analyzed by two-way analysis of variance and Student,Newman,Keuls tests (, = 0.05). One cycle of microwave disinfection decreased the deflection at fracture and fracture energy of Tokuso Rebase Fast and New Truliner specimens. The strength of denture bases microwaved daily for 7 days was similar to the strength of those immersed in water for 7 days. Microwave disinfection increased the water sorption of all materials and affected the solubility of the reline materials. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 [source]

Adhesive bonding of titanium nitride-plated stainless steel for magnetic attachments

EUROPEAN JOURNAL OF ORAL SCIENCES, Issue 3 2001
Yohsuke Taira
The purpose of this study was to evaluate adhesive bonding of resin to titanium nitride ion-plated stainless steel in order for magnetic attachments to survive in the oral environment. Two primers, Cesead II Opaque Primer (CPII) and Metal Primer II (MPII), and one bonding agent, Super-Bond C&B (SB), were used. The surfaces of stainless steel disks were ground and then plated with titanium nitride. After the primer and SB resin were applied, a self-curing resin was bonded to the metal surfaces. Shear bond strengths were determined after 24 h of water storage and after 2,000 thermocycles. Titanium nitride ion-plated stainless steel showed bond strength comparable to the non-plated material. After thermocycling, all specimens of the group no primer/no SB were debonded. The bond strengths of groups CPII/no SB, MPII/no SB and no primer/SB were significantly lower bond strengths than groups CPII/SB and MPII/SB. An appropriate combination of primer and bonding agent should be selected when bonding a magnetic attachment to the denture base. [source]

Inhibition of biofilms associated with dentures and toothbrushes by tetrasodium EDTA

JOURNAL OF APPLIED MICROBIOLOGY, Issue 6 2007
D.A. Devine
Abstract Aims:, We examined the efficacy of tetrasodium EDTA in eradicating biofilms derived from salivary inocula or pure cultures of Candida albicans on discs of polymethyl methacrylate (PMMA) denture base or on toothbrushes that had been used normally for 4,8 weeks. Its efficiency in virus neutralization was also determined. Methods and Results:, Overnight (16 h) treatment with 4% (w/v) tetrasodium EDTA solution reduced salivary and C. albicans biofilm viable counts by ,99%. Biofilm removal was confirmed using confocal laser scanning microscopy. Presence/absence of sucrose during biofilm formation had no effect on killing efficacy. Prolonged treatment of PMMA with tetrasodium EDTA did not influence subsequent formation of C. albicans biofilms or affect surface roughness of the PMMA, but it reduced subsequent biofilm formation from a salivary inoculum. Infectivities of herpes simplex virus and polio virus suspensions were reduced by >99·99% by treatment for 1 and 2 h, respectively. Conclusions:, Tetrasodium EDTA solution efficiently disinfected toothbrushes and PMMA discs, with the detachment of biofilms, and rapidly neutralized both nonenveloped and enveloped viruses. Significance and Impact of the Study:, Dentures and toothbrushes become contaminated by bacterial biofilms and by viruses. There is a need for disinfection methods that are rapidly effective, cost-effective, nontoxic and easily implemented. These studies indicate that tetrasodium EDTA solution has disinfection applications in the oral care field. [source]

Effect of disinfection by microwave irradiation on the strength of intact and relined denture bases and the water sorption and solubility of denture base and reline materials

Dynesthetic and Dentogenic Concept Revisited

JOURNAL OF ESTHETIC AND RESTORATIVE DENTISTRY, Issue 3 2002
WILLIAM S. JAMESON BS
ABSTRACT: The dynesthetic and dentogenic concept, when applied, provides a more natural, harmonious prosthesis, which not only is desired by patients, but also is a quality of care they deserve. Outstanding esthetics can be achieved by simple guidelines, using tooth molds specifically sculpted for males and females, arranging prosthetic teeth to correspond with personality and age and sculpting the matrix (visible denture base) with more natural contours. There is no reason for edentulous individuals to be provided with care of any less quality than that available with other procedures, such as crowns, bridges, veneers, or implant restorations. Providing this upscale product can be rewarding and satisfying to patient and operator alike. This concept produces superior results no matter what posterior occlusal scheme is employed but, in the opinion of the author, works best when used in conjunction with a noninterceptive linear occlusion approach (not to be confused with lingualized occlusion), which precludes anterior contact. CLINICAL SIGNIFICANCE: Dentogenics provides an approach to esthetics in prosthodontics that enables the dentist to create a restoration in harmony with the patient's objective personality. This concept considers gender, I age, and personality to restore the patient's dignity and unique individuality that has been missing in far too many prostheses. [source]

Effect of palate covering on bolus-propulsion time and its contributory factors

JOURNAL OF ORAL REHABILITATION, Issue 1 2006
Y. KODAIRA
summary, The aim of this study was first to investigate whether the covering of the palatal mucosa with a denture base affects or not the bolus-propulsion time, and second if there was such an effect then investigate the possible contributory factors which have influence on the propulsion time. The propulsion time was measured in 21 young normal edentulous subjects under five different conditions: a complete palatal covering, non-covered palate, anterior palatal covering, posterior palatal covering and surface anaesthetized palate. As possible contributory factors palatal morphometric parameters, as well as tongue pressure were also measured. The data were analysed on the following way: changes when the palate was complete covered and non-covered, effects of sensation reduction after topic anaesthesia, effects of differences in the covering site, effects of palatal morphometric parameters and effects of tongue pressure. Ten subjects exhibited significant differences in the propulsion time when comparing the data between the complete palatal covering and the non-covered palate condition (change group). Eleven subjects did not show changes (unchanged group). Effects in the propulsion time were also recognized with posterior palatal covering-palate and superficially anaesthetized palate. With regard to the tongue pressure, significant differences during swallowing were observed. These results indicated that the bolus propulsion time into the oropharynx was affected by the palatal covering in some subjects. Moreover, the sensation in the posterior region of the hard palate, as well as the tongue pressure were also factors which affected the propulsion time during swallowing. [source]

Detection of improvement in the masticatory function from old to new removable partial dentures using mixing ability test

JOURNAL OF ORAL REHABILITATION, Issue 9 2005
A. ASAKAWA
summary, The aim of this study was to determine the sensitivity of the Mixing Ability Test to detect improvement of masticatory function in subjects on transition from old to new removable partial dentures. Thirty-two subjects (seven males, 25 females, mean age 65·0 years) with distal extension partially edentulous area in mandible and/or maxilla participated in the study. The following reasons were presented for replacing the old removable partial dentures with new ones: fracture and/or poor fitness of retainers, extraction of abutment teeth, poor fitness of denture base, severe wear of artificial teeth and request for metal base dentures. Masticatory function with old and new removable partial dentures after an adaptation period (mean 27·4 weeks) was evaluated by the Mixing Ability Test. Subjects were asked to masticate five two-coloured wax cubes with each removable partial denture. Mixing Ability Index was obtained from the colour mixture and shape of the masticated cubes. Wilcoxon signed-rank test was used to test the difference of Mixing Ability Indexes between old and new removable partial dentures. The mixing ability indexes with new removable partial dentures (mean ± s.d.: 0·70 ± 0·68) was significantly higher (P < 0·001) than those with old removable partial dentures (,0·11 ± 1·13). The results suggest that the Mixing Ability Test was capable of detecting improvement in masticatory function with new removable partial dentures. [source]

Influence of working side contacts on masticatory function for mandibular distal extension removable partial dentures

JOURNAL OF ORAL REHABILITATION, Issue 3 2003
S. Sueda
summary The aim of this study was to clarify the influence of working side contacts for masticatory function for a distal extension removable partial denture. Five subjects who had edentulous arches from second premolar to second molar opposing natural teeth participated. Working side contacts were altered by using three types of artificial teeth attached to the denture base. A-form teeth made contact with opposite teeth while acting as the working side in a lateral excursion. The cusp angles of B- and C-form teeth were decreased by 10° and 20°, respectively compared with A-form teeth. B-and C-form teeth discluded with opposite teeth on the working side. Subjects were asked to perform two kinds of masticatory performance test. Obtained data were evaluated by the repeated-measures anova and the Tukey test for multiple comparisons. Results revealed that there was a significant difference (P=0·001) in the three types of teeth in the mixing ability test and the value of A-form teeth was statistically less value than those of the other teeth. However, there was no significant difference in the comminuting ability test. These results suggested that working side contacts between artificial teeth and opposite natural teeth influenced mixing ability, but not comminuting ability. [source]

Degradation of repaired denture base materials in simulated oral fluid

JOURNAL OF ORAL REHABILITATION, Issue 3 2000
C.-T. Lin
This in vitro study evaluates the degradation of repaired denture bases upon immersion in a simulated oral fluid. Denture base materials (Luciton 199®), after being repaired by Repair Material® and Triad®, using three different joint surface designs (butt, round and 45 ° bevel), were immersed onto 99·5 vol.% ethanol/water solution (with similar solubility parameter) for various amounts of time (0,72 h). The flexural loads of the six combination of groups were measured by the three-point bending tests using a universal testing machine. Acoustic emission (AE) during sample fracturing were processed using the MISTRA 2001 system. The fracture pattern and surface details of the interface were examined with a scanning electronic microscope (SEM). Data were analysed using three-way anova and Tukey LSD tests. SEM micrographs of the fracture interface were used to differentiate the fracture mode. The flexural loads (2·72±0·51 Kgf) of the round joint specimens were significantly higher (P<0·05) than those (butt: 1·66±0·38 Kgf, 45 ° bevel: 1·93±0·41 Kgf) of the other two designs. This corresponds to the microscopic examination in which more cohesive failure mode was found for the round joint group after storage. The flexural loads (2·54±0·39 Kgf) of the specimens repaired with Triad® were significantly higher (P<0·05) than those (1·59±0·40 Kgf) of specimens repaired with Repair Material®. Significant progressive reduction of the flexural load and/or AE signals of the specimens was noted in proportion to the length of time of the immersion in the simulated oral fluid. Mechanical strength of a denture base repaired with a round joint design and light-cured material is significantly higher after immersion in simulated oral fluid. [source]

Load transfer characteristics of unilateral distal extension removable partial dentures with polyacetal resin supporting components

AUSTRALIAN DENTAL JOURNAL, Issue 1 2009
T Jiao
Abstract Background:, To photoelastically examine load transfer by unilateral distal extension removable partial dentures with supporting and retentive components made of the lower stiffness polyacetal resins. Methods:, A mandibular photoelastic model, with edentulous space distal to the right second premolar and missing the left first molar, was constructed to determine the load transmission characteristics of a unilateral distal extension base removable partial denture. Individual simulants were used for tooth structure, periodontal ligament, and alveolar bone. Three designs were fabricated: a major connector and clasps made from polyacetal resin, a metal framework as the major connector with polyacetal resin clasp and denture base, and a traditional metal framework I-bar removable partial denture. Simulated posterior bilateral and unilateral occlusal loads were applied to the removable partial dentures. Results:, Under bilateral and left side unilateral loading, the highest stress was observed adjacent to the left side posterior teeth with the polyacetal removable partial denture. The lowest stress was seen with the traditional metal framework. Unilateral loads on the right edentulous region produced similar distributed stress under the denture base with all three designs but a somewhat higher intensity with the polyacetal framework. Conclusions:, The polyacetal resin removable partial denture concentrated the highest stresses to the abutment and the bone. The traditional metal framework I-bar removable partial denture most equitably distributed force. The hybrid design that combined a metal framework and polyacetal clasp and denture base may be a viable alternative when aesthetics are of primary concern. [source]

Dimensional accuracy of upper complete denture bases: the effect of metallic flask closure methods

GERODONTOLOGY, Issue 1 2009
Rafael Leonardo Xediek Consani
Objectives:, To verify the dimensional accuracy of upper complete denture bases under the effect of different methods of metallic flask closure. Materials and methods:, Wax record bases were assigned to six groups: 1,2: traditional clamp; 3,4: RS system; and 5,6: flask with screws. Flasks were immediately polymerised or bench stored for 6 h prior to polymerisation. Resin base-cast sets were sectioned at regions corresponding to the canines, first molars and posterior palatal zone. Gap discrepancies were measured at five points: right and left ridge crests, palatal midline, and right and left marginal limits of the flanges. An optical micrometer was used for measurement purposes. Results:, Data were submitted to anova, and the means compared by Tukey's test (, = 0.05). Results revealed significant differences in the flask closure technique, polymerisation time, section, and their interactions. Discrepancy values for the RS system and flask with screws were significantly lower than those related to the traditional clamp, regardless of whether resin polymerisation was immediate or delayed for 6 h. Conclusions:, Flask closure methods should be considered when the denture base stability and comfort of the patient are being assessed during clinical use of the dentures. [source]

Bonding acrylic teeth to acrylic resin denture bases: a review

GERODONTOLOGY, Issue 3 2006
S. B. Patil
Partial or complete dentures are more commonly constructed for the elderly group of the population. Teeth debonding from the dentures can be frustrating to the patients as well as the dentist. Research has been carried out and is continuing to study the issue of bonding acrylic teeth to the denture base resin. The present review takes into account the majority of research papers published in the last five decades for determining the bond strength. Selection of more compatible combinations of denture base resins and acrylic teeth may reduce the number of prosthesis fractures and the resultant repairs. [source]

Effect of disinfection by microwave irradiation on the strength of intact and relined denture bases and the water sorption and solubility of denture base and reline materials

Effect of cooling procedure on final denture base adaptation

JOURNAL OF ORAL REHABILITATION, Issue 8 2002
S. M. Ganzarolli
Summary Well-fitted dentures prevent hyperplasic lesions, provide chewing efficiency and promote patient's comfort. Several factors may affect final adaptation of dentures, as the type of the acrylic resin, the flask cooling procedure and the water uptake. This investigation evaluated the effect of water storage and two different cooling procedures [bench cooling (BC) for 2 h; running water (RW) at 20 °C for 45 min] on the final adaptation of denture bases. A heat-cured acrylic resin (CL, Clássico, Clássico Artigos Odontológicos) and two microwave-cured acrylic resins [Acron MC, (AC) GC Dent. Ind. Corp.; Onda Cryl (OC), Clássico Artigos Odontológicos] were used to make the bases. Adaptation was assessed by measuring the weight of an intervening layer of silicone impression material between the base and the master die. Data was submitted to ANOVA and Tukey's test (0·05). The following means were found: (BC) CL=0·72 ± 0·03 a; AC=0·70 ± 0·03 b; OC=0·76 ± 0·04 c//(RW) CL= 1·00 ± 0·11 a; AC=1·00 ± 0·12 a; OC=0·95 ± 0·10 a. Different labels join groups that are not statistically different (P > 0·05). Comparisons are made among groups submitted to the same cooling procedure (BC or RW). The conclusions are: interaction of type of material and cooling procedure had a statistically significant effect on the final adaptation of the denture bases (P < 0·05); water storage was not detected as a source of variance (P > 0·05) on the final adaptation. [source]

Degradation of repaired denture base materials in simulated oral fluid

Effect of Aluminum Oxide Addition on the Flexural Strength and Thermal Diffusivity of Heat-Polymerized Acrylic Resin

JOURNAL OF PROSTHODONTICS, Issue 6 2008
Ayman E. Ellakwa BDS
Abstract Purpose: This work was undertaken to investigate the effect of adding from 5% to 20% by weight aluminum oxide powder on the flexural strength and thermal diffusivity of heat-polymerized acrylic resin. Materials and Methods: Seventy-five specimens of heat-polymerized acrylic resin were fabricated. The specimens were divided into five groups (n = 15) coded A to E. Group A was the control group (i.e., unmodified acrylic resin specimens). The specimens of the remaining four groups were reinforced with aluminum oxide (Al2O3) powder to achieve loadings of 5%, 10%, 15%, and 20% by weight. Specimens were stored in distilled water at 37°C for 1 week before flexural strength testing to failure (5 mm/min crosshead speed) in a universal testing machine. Results were analyzed by one-way analysis of variance and post hoc Tukey paired group comparison tests (p < 0.05). Weibull analysis was used to calculate the Weibull modulus, characteristic strength, and the required stress for 1% and 5% probabilities of failure. Cylindrical test specimens (5 specimens/group) containing an embedded thermocouple were used to determine thermal diffusivity over a physiologic temperature range (0 to 70°C). Results: The mean flexural strength values of the heat-polymerized acrylic resin were (in MPa) 99.45, 119.92, 121.19, 130.08, and 127.60 for groups A, B, C, D, and E, respectively. The flexural strength increased significantly after incorporation of 10% Al2O3. The mean thermal diffusivity values of the heat-polymerized acrylic resin (in m2/sec) were 6.8, 7.2, 8.0, 8.5, and 9.3 for groups A, B, C, D, and E, respectively. Thermal diffusivities of the composites were found to be significantly higher than the unmodified acrylic resin. Thermal diffusivity was found to increase in proportion to the weight percentage of alumina filler, which suggested that the proper distribution of alumina powders through the insulating polymer matrix might form a pathway for heat conduction. Conclusion: Al2O3 fillers have potential as added components in denture bases to provide increased flexural strength and thermal diffusivity. Increasing the flexural strength and heat transfer characteristics of the acrylic resin base material could lead to more patient satisfaction. [source]

Flexural properties of glass fibre reinforced acrylic resin polymers

AUSTRALIAN DENTAL JOURNAL, Issue 1 2006
IH Tacir
Abstract Background: In recent years, glass fibres have been used to strengthen denture base resins. A major difficulty in using reinforcing fibres with multiphase acrylic resins, such as powder liquid resins, is inadequate impregnation of the fibres with the resin. Methods: This investigation examined the reinforcing effect of glass fibres on the fracture resistance and flexural strength of acrylic denture base resins. Eighty identical specimens were formed in specially designed moulds in accordance with the manufacturer's recommendations. The four experimental groups were prepared and these consisted of conventional acrylic resin and the same resin reinforced with glass fibres. Ten specimens were fabricated in a standardized fashion for each experimental group. Flexural strength was tested using a 3-point universal testing machine. Results: In this study, statistically significant differences were found in the flexural strength of the specimens (P<0.05). The injection-moulded, fibre-reinforced group had significantly lower flexural strength than the injection-moulded group (P<0.001), and the microwave-moulded, fibre-reinforced group had lower flexural strength than the microwave-moulded group. The fracture resistance was significantly higher in the injection-moulded, fibre-reinforced group than in the injection-moulded group (P<0.05), and the fracture resistance was significantly higher in the microwave-moulded, fibre-reinforced group than in the microwave-moulded group. Conclusion: Within the limitations of this study, the flexural strength of heat-polymerized PMMA denture resin was improved after reinforcement with glass fibres. It may be possible to apply these results to distal extension partial and complete denture bases. [source]