Kairul Annuar, Amira Farhana and Zakaria, Nor Nadia and Wan Hassan, Wan Nurazreena and Razak, Fathilah Abdul (2022) Microbial adhesion, physical and mechanical properties of removable retainer materials in different storage conditions: An in vitro study. In: 15th Dental Postgraduate Conference of the Faculty of Dentistry, Universiti Malaya, 21-22 September 2022, Balai Ungku Aziz, Faculty of Dentistry, Universiti Malaya. (Unpublished)
Full text not available from this repository.Abstract
Introduction: Inadequate evidence exists to recommend a way of storing removable retainers. As a result, clinicians gave conflicting advice to their patients about retainer wear and care. Objectives: The present study aimed to evaluate the effects of storage conditions on the microbial adhesion, physical and mechanical properties of two common removable retainer materials, which were polyethylenterephthalate glycol (PETG) and polymethyl methacrylate (PMMA). Methodology: Twenty test samples [PETG (n=10) and PMMA (n=10)] were prepared at standard dimensions (PMMA, 30 x 5 x 2 mm; PETG, 30 x 5 x 1 mm). The samples were divided into 4 groups: 1) PMMA stored in wet condition 2) PMMA stored in dry condition 3) PETG stored in wet condition and 4) PETG stored in dry condition. Samples were incubated at 37°C in a mixture of artificial saliva and bacteria for 8 hours daily to mimic part-time wear of retainers, brushed with standardised strokes for 10-15 seconds and cleaned with distilled water. After cleaning, wet group samples were stored in distilled water, while dry group samples were stored in a dry container (desiccator) for 14 hours. Samples underwent a series of tests at baseline and 14-day: (1) microbial adhesion test by counting the colony forming unit per ml (CFU/ml); (2) water sorption by measuring weight and volume; (3) surface roughness test using atomic force microscope (AFM); and (4) flexural strength/modulus test by three-point bending test using a Universal Testing Machine (UTM). The procedures were repeated daily for 14 days. Independent sample t-test was applied to compare the dependent variables of PTEG and PMMA at baseline and after experiment, and two-way analysis of variance (ANOVA) was carried out to investigate the interaction between the two samples and the storage conditions with statistical significance set at p = 0.05. Results: Results revealed significant differences in the microbial adhesion (p < 0.001) and water sorption (p = 0.020) of PMMA compared to PETG in wet and dry storage conditions, but no significant differences in surface roughness (p = 0.659) and flexural strength/modulus (p = 0.593). PMMA in wet condition resulted in most microbial adhesion, followed by PMMA in dry condition, then PETG in wet condition, and least PETG in dry condition (p < 0.001). Most water absorption took place in PETG in wet condition, followed by PMMA in wet condition, then PMMA in dry condition and least PETG in dry condition (p = 0.020). Conclusion: In conclusion, dry storage condition for both PMMA and PETG exhibited less microbial adhesion, less surface roughness, less water sorption and higher flexural strength/modulus than in wet storage condition.
| Item Type: | Conference or Workshop Item (Paper) |
|---|---|
| Funders: | UNSPECIFIED |
| Uncontrolled Keywords: | removable retainer materials; polymethyl methacrylate; polyethylenterephthalate glycol; storage conditions |
| Subjects: | R Medicine > RK Dentistry |
| Divisions: | Faculty of Dentistry > Department of Paediatric Dentistry & Orthodontics |
| Depositing User: | Ms. Juhaida Abd Rahim |
| Date Deposited: | 02 Dec 2024 03:17 |
| Last Modified: | 02 Dec 2024 03:17 |
| URI: | http://eprints.um.edu.my/id/eprint/47191 |
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