The effects of cyclic stress on dental polymethylmethacrylate

As, Hargreaves

doi:10.1111/j.1365-2842.1983.tb00102.x

Cited by 20 publications

(18 citation statements)

References 18 publications

(14 reference statements)

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“…Thermal effects from the ingestion of hot and cold food and drinks may also have a deleterious effect ( Hargreaves, 1983; Montes‐G & Draughn, 1986). The same researchers with Iwahori (1992) have demonstrated that thermal stress affects the surface roughness, gloss, color tone, and abrasion resistance of the resin.…”

Section: Discussionmentioning

confidence: 99%

Flexural strength of rebased denture polymers

Archadian

Kawano

Ohguri

et al. 2000

J of Oral Rehabilitation

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The properties of denture base and reline resins may be affected by daily changes between room temperature and mouth temperature. The purpose of the study was to evaluate the effect of thermocycling on the flexural strength of the relined denture base polymer with reline resin. Three denture base resins, three hard reline resins and their combinations were tested. Fourteen specimens, 65x10x2.5 mm, were fabricated for each material. Polymer combination specimens were made using 1.5 mm hard reline resin on 1.0 mm cured denture base resins. Half of the specimens were stored for 50+/-2 h in distilled water at 37 degrees C, while the other half were thermocycled for 20 000 cycles between 4 and 60 degrees C. Three point bending tests were conducted on a universal testing machine at a cross-head speed of 0.5 cm/s. The flexural strengths were measured and a statistical analysis was performed on the data using three-way ANOVA (P<0.05). The results showed that the flexural strength of relined denture base polymer was significantly higher than that of hard reline polymer. Thermocycling did not affect the flexural strength of the relined denture base polymers, whereas the denture base polymer and reline polymer alone showed a decrease in strength after thermocycling.

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Section: Discussionmentioning

confidence: 99%

Flexural strength of rebased denture polymers

Archadian

Kawano

Ohguri

et al. 2000

J of Oral Rehabilitation

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“…Such thermal cycling in a wet environment may cause degradation of the denture polymers 1,17 , and the heat stress may increase water sorption because of an extension of the distance between the polymer chains 1 . Absorbed water can act as a plasticizer and soften the denture, thus reducing the mechanical properties of the material 1,9 .…”

Section: Introductionmentioning

confidence: 99%

Effect of thermal cycling on denture base and autopolymerizing reline resins

et al. 2013

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Objective:This study evaluated the fracture toughness (FT) of denture base and autopolymerizing reline resins, with and without thermocycling (T). Material and Methods:Specimens of each material (denture base acrylic resin - Lucitone 550 - L; autopolymerizing reline resins - Ufi Gel Hard-UH, Tokuyama Rebase II-TR, New Truliner- NT and Kooliner-K), were produced, notched and divided into two groups (n=10): CG (control group of autopolymerizing reline resins and L): FT tests were performed after polymerization; TG (thermocycled group): FT tests were performed after T (5ºC and 55ºC for 5,000 cycles). Results:Results (MPa.m(1/2)) were analyzed by two-way ANOVA and Tukey's test (p=0.05). L exhibited the highest FT mean values in both groups (CG - 2.33; TG - 2.17). For the CG groups, NT showed the highest FT (1.64) among the autopolymerizing reline resins, and K the lowest (1.04). After T, when the autopolymerizing reline resins were compared, a statistically significant difference in FT was found only between the NT (1.46) and TR (1.00). Conclusions:Thermocycling increased the FT of K and did not influence the FT of L, UH, TR and NT.

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“…Some concern arose with the greater rate of decay in those specimens which had been cycled in water at 37"C: an apparent decay of 15"{, over the same test period was considerably more than had been expected. The sequelae of a denture base becoming too flexible have already been mentioned (Hargreaves, 1983); it is worth remembering that clinical damage may ensue before 'failure' of the base material.…”

Section: Discussionmentioning

confidence: 97%