Purpose: Acrylic resin complete dentures exhibit dimensional changes mainly because of
processing shrinkage and expansion because of water uptake. The aim of this 5-year
clinical study was to determine the dimensional changes occurring during construction
and in service in maxillary complete dentures made of two types of acrylic resin.
Materials and Methods: Complete dentures were constructed for 17 edentulous patients.
Nine patients received dentures made of conventional heat-cured acrylic resin, and eight
patients received dentures made of rapid heat-cured acrylic resin. Measurements were
taken across three reference points (second molars bilaterally and central incisors) on six
occasions: at the flasking stage, at the denture insertion appointment, and after 1 week, 1
month, 3 months, and 5 years of use. The data obtained were analyzed using one-factor
repeated-measures ANOVA, one-way ANOVA, and Duncan’s multiple comparisons test.
Results: The two types of dentures showed the same pattern of dimensional changes. A
shrinkage of up to 0.27% was estimated at the insertion stage. During the first 3 months
of use, a decrease of the initial dimensional change was observed. After a 3-month
period, a gradual compensation for the initial shrinkage started to take place. At the end
of the study period (5 years), an expansion of up to 0.35% was measured. Conclusion:
Maxillary complete dentures made of either conventional or rapid heat-cured acrylic
resin exhibited dimensional changes that were considered clinically acceptable.
Int J Prosthodont 2003;16:78–81.