ABSTRACT
Background: Root canal obturation is an important step in endodontic treatment, which is performed aiming to three-dimensionally seal the canal and prevent microleakage, reentry, and proliferation of microorganisms in the root canal system. On the other hand, microleakage eventually leads to root canal treatment failure. Sealing ability is an important property of endodontic sealers. This in vitro study aimed to compare the quality of apical seals obtained by three endodontic sealers. Materials and Methods: This in vitro experimental study evaluated 48 extracted single-canal maxillary incisors. Hard- and soft-tissue residues were removed and the teeth were immersed in 5.25% of sodium hypochlorite for disinfection. The teeth were decoronated at the cementoenamel junction with a diamond disc such that 10 mm of root length remained. Canal patency was ensured using a #10 K-file. The canals were then instrumented with ProTaper rotary system. The canals were randomly divided into three experimental groups for the application of Adseal, Proseal, and AH26 sealers, and positive and negative control groups. Sealers were applied in the canals using lateral compaction technique. The external root surfaces were then coated with two layers of nail varnish except for the apical 3 mm. The amount of microleakage was quantified using the dye-penetration technique. The Tukey's test was used to compare the microleakage between the experimental and control groups. The Kruskal-Wallis test was applied to compare the microleakage of experimental groups (P < 0.05). Results: The amount of microleakage in canals filled with Adseal, Proseal, and AH26 sealers with lateral compaction technique was 2.33 ± 0.64, 2.2 ± 0.81, and 2.22 ± 0.71 µm, respectively. No significant difference was noted among the three sealers regarding microleakage (P = 0.84). However, the amount of microleakage in the sealer groups was significantly lower than that in the control group (P < 0.001). Conclusion: The application of Adseal, Proseal, and AH26 had equal efficacy for the provision of optimal apical seal in filling of root canals with lateral compaction technique. The application of sealers yielded a significantly superior apical seal compared with the control group.
ABSTRACT
Background and Purpose: The human mouth mucosal surface is colonized by indigenous microflora, which normally maintains an ecological balance among different species. However, certain environmental or biological factors may disrupt this balance, leading to microbial diseases. Candida albicans biofilms are formed on indwelling medical devices and have an association with both oral and invasive candidiasis. This study aimed to compare the amount of adherent C. albicans and the biofilm formed on different denture base materials. The adhesion of C. albicans to denture base materials is widely recognized as the main reason for the development of denture stomatitis. Materials and Methods: In total, 56 polymethyl methacrylate (PMMA) acrylic resin disc-shaped samples were divided into four groups as follows: 1) chemically polymerized PMMA, 2) heat-polymerized PMMA, 3) computer-aided design and computer-aided manufacturing (CAD/CAM) PMMA in high polish, and 4) CAD/CAM resins in glazed form. The adherent cells and formation of C. albicans strains (562, 1905, 1912, and 1949) biofilm were measured by the 2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide (XTT) method and use of a microplate reader. Moreover, morphological alterations of C. albicans cells were investigated using scanning electron microscopy (SEM). Results: The biofilm formation was significantly lower on CAD/CAM acrylic resins, compared to conventional denture base materials. The obtained results were confirmed by the SEM images of C. albicans biofilms. CAD/CAM PMMA-based polymers may be preferable to inhibit C. albicans biofilm formation and reduce Candida-associated denture stomatitis in long-term use. Conclusion: Based on the findings, the CAD/CAM technique can be used as an efficient technique for denture fabrication as it inhibits microbial accumulation, and consequently, microbial biofilm.
