Influence of storage period and effect of different brands of acrylic resin on the dimensional accuracy of the maxillary denture base

Abstract

The aim of this study was to evaluate the dimensional changes of denture bases made from different resins after different storage periods. For this purpose, 25 sets of plaster models/resin bases were prepared using 4 acrylic resins submitted to two types of polymerization: 1-QC-20 submitted to polymerization by microwave energy; 2-QC-20 submitted to polymerization by water hot bath; 3-Vipi Cril submitted to polymerization by water hot bath; 4-Vipi Wave submitted to polymerization by microwave energy; and 5-Onda Cryl submitted to polymerization by microwave energy. After polymerization, the specimens were sectioned for accuracy readings using a comparison microscope. Readings were taken at 3 points: the crests of the right (A) and left (B) ridges, and the median region of the palate, in 4 different periods. The data obtained were submitted to two-way ANOVA and Tukey's test at 5% significance level. The greatest distortions were found in the posterior palatal region of the base (M), with statistically significant difference (p<0.05) for the studied resins. All acrylic resins presented dimensional changes and the storage period influenced these alterations.

Effect of Flexible Denture Base on Retention of Complete Denture

“…After three months, the two type of denture showed statistically non-significant increase in retention values over retention values at one month, this might be due to the neuromascular control and patients adaptability to their dentures. But still when we compared the retention values at three months of the flexible acrylic resin and the conventional heat cured acrylic resin, flexible acrylic resin showed statistically significant higher retention values over the conventiona lheat cured acrylic resin (9).…”

“…It's important that patient perceive their denture as retentive during function and as esthetically agreeable in order to meet the psychodynamics required by the patient (9) .In this study denture retention obtained by using two different denture base materials, conventional heat cured acrylic resin and heat cured thermoplastic resin, was compared.…”

“…It's important that patient perceive their denture as retentive during function and as esthetically agreeable in order to meet the psychodynamics required by the patient (9) . After one month, both type of dentures showed statistically significant increase in retention values, because each material seemed to behave in a negative way differently, where the conventional resin has been assumed significantly higher water sorption than the flexible resin (10) .…”

The Effect of Time and Three Different Storage Environments on the Dimensional Stability of Acrylic Removable Orthodontic Appliances

“…However Miessi et al 14 showed that when specimens are kept in water for longer periods of time (2 months) significant expansion may occur and it would damage appliance fitness. This further expansion is caused by the great capacity of resin for water sorption.…”

Maksiller tam protezin boyutsal hassasiyeti üzerinde işlememenin etkisi

“…Bu safhada polimerizasyon büzülmesi tamamlanmış olacağından meydana gelen büzülme termal kökenli olup rezinlerin bileşimine bağlıdır. Gerilimler ve bunun sonucunda meydana gelen distorsiyonları gidermek için çeşitli muflalama teknikleri ve rezin formülasyonları geliştiril-mektedir (3)(4)(5).…”