Effect of organic acids in dental biofilm on microhardness of a silorane-based composite.
10.5395/rde.2015.40.3.188
- Author:
Sedighe Sadat HASHEMIKAMANGAR
1
;
Seyed Jalal POURHASHEMI
;
Mohammad TALEBI
;
Nazanin KIOMARSI
;
Mohammad Javad KHARAZIFARD
Author Information
1. Department of Operative Dentistry, Dental School, Tehran University of Medical Sciences, International Campus, Tehran, Iran. smhk58950@gmail.com
- Publication Type:Original Article
- Keywords:
Dental biofilm;
Methacrylate-based composite resin;
Microhardness;
Organic acids;
Silorane-based composite resin
- MeSH:
Acetic Acid;
Biofilms*;
Composite Resins;
Immersion;
Lactic Acid;
Water
- From:Restorative Dentistry & Endodontics
2015;40(3):188-194
- CountryRepublic of Korea
- Language:English
-
Abstract:
OBJECTIVES: This study evaluated the effect of lactic acid and acetic acid on the microhardness of a silorane-based composite compared to two methacrylate-based composite resins. MATERIALS AND METHODS: Thirty disc-shaped specimens each were fabricated of Filtek P90, Filtek Z250 and Filtek Z350XT. After measuring of Vickers microhardness, they were randomly divided into 3 subgroups (n = 10) and immersed in lactic acid, acetic acid or distilled water. Microhardness was measured after 48 hr and 7 day of immersion. Data were analyzed using repeated measures ANOVA (p < 0.05). The surfaces of two additional specimens were evaluated using a scanning electron microscope (SEM) before and after immersion. RESULTS: All groups showed a reduction in microhardness after 7 day of immersion (p < 0.001). At baseline and 7 day, the microhardness of Z250 was the greatest, followed by Z350 and P90 (p < 0.001). At 48 hr, the microhardness values of Z250 and Z350 were greater than P90 (p < 0.001 for both), but those of Z250 and Z350 were not significantly different (p = 0.095). Also, the effect of storage media on microhardness was not significant at baseline, but significant at 48 hr and after 7 day (p = 0.001 and p < 0.001, respectively). Lactic acid had the greatest effect. CONCLUSIONS: The microhardness of composites decreased after 7 day of immersion. The microhardness of P90 was lower than that of other composites. Lactic acid caused a greater reduction in microhardness compared to other solutions.
