Abstract
Purpose: The aim of the study was to compare between zirconia reinforced acrylic resins with that conventional acrylic resins (PMMA) regarding bacterial colonization and some mechanical properties (flexural strength, surface roughness, and surface hardness). Material and methods: Clinical study: sixteen completely edentulous patients were randomly selected which their ages ranged from 50-60 years. Patients were divided into two groups. Patients in the first group received maxillary and mandibular complete denture made of PMMA (Group І) and patients in the second group received maxillary and mandibular complete denture made of ZrO2 reinforced acrylic resins (Group ІІ). Microbial biofilm was evaluated after three, six and nine months for each patient. Laboratory study: sixty specimens were constructed. The specimens were divided into two groups. Thirty specimens of PMMA (Group І) and thirty specimens of ZrO2 reinforced PMMA (Group ІІ) for testing FS, surface hardness and surface roughness Results: The results of microbial biofilm evaluation in group ІІ was significantly higher than that found in group I. The laboratory study results showed that FS and surface roughness in ZrO2 reinforced PMMA were significantly higher than conventional PMMA. Further, the study showed that an insignificant increase of surface hardness in ZrO2 reinforced PMMA when compared with conventional PMMA. Conclusion: Reinforcement of acrylic resin with ZrO2 in PMMA results in an increase of the microbial colonization and surface roughness of denture and improvement of some mechanical properties as flexural strength and surface hardness.