Showing 3 results for Modaber
Ebrahim Ataei, Maryam Modaber, Ali Reza Daneshkazemi, Mahnaz Ersi,
Volume 2, Issue 1 (1-2014)
Abstract
Introduction: This in vitro study aimed to compare two filling techniques and the effect of retention groove on microleakage of siloran and methacrylate based composites.
methods: class V cavities (3×4×1.5×mm) were prepared on the buccal and lingual surfaces in 48 extracted human premolars. The cavities were restored with two different types of composites 1) silorane-based resin composite (Filtek™ P90 Silorane, 3M ESPE) with its dedicated adhesive system(P90 system adhesive) and, 2) methacrylate-based resin composite(Z250,3M ESPE) with clearfil SE bond adhesive resin system. Each of these two groups was then subdivided into four groups (12 restoration). G1: with retentive groove- incremental G2: without retentive groove- incremental G3: with retentive groove- bulky G4: without retentive groove- bulky .The retentive grooves were placed at the axio- occlusal and axio-gingival line angles. The teeth were subjected to thermocycling regime (500×, 5-55°C) and were stained with 2% methylene blue dye and then were sectioned and viewed under a stereomicroscope. Data were analyzed with Kruskal-Wallis and Mann-Whitney U test via SPSS.17 software.
Results: there was no significant difference between the filling technique and cavity preparation in methacrylate-base resin composite (P> 0.05). However, a significant difference was found in siloran-based resin composite (P= 0.000). Within group pairs of siloran-based composite, there was a significant difference between the G1 and G3, G1 and G4, G2 and G4. Conclusions: The base of composite had no effect on microleakage, though combination of layering restotative technique and groove placement resulted in lower microleakage in both methacrylate and silorane composites. However, in methacrylate composite, the decrease was not significant.
Ebrahim Ataei, Maryam Modaber, Abd Rahim Davari, Forogh Sadat Fallahtafti,
Volume 2, Issue 1 (1-2014)
Abstract
Introduction: Micro leakage is one of the most important complications of direct tooth-colored restorations. the purpose of this investigation was to evaluate the effect of delayed placement of composite and delayed curing of two step self etch adhesive on microleakage of class V composite restorations.
Methods:72 class V cavities were prepared in buccal and lingual surfaces of 36 premolars. the specimens randomly assigned into 6 groups. adhesive was photocured in 3of the groups immediately and then composite was applied immediately, with 2min and 5min delay.in the other 3 groups, adhesive was photocured after a 30 second delay and then composite was placed immediately, with 2min and 5min delay. After thermocycling and immersion in 2% methylene blue, the teeth were sectioned and dye penetration was observed under a stereomicroscope and results were analyzed using SPSS17, kruskal wallis and mann whitney test.
Results: kruskal wallis test showed significant difference between groups immediately, 2 and 5minutes delay placement of composite(P =0.001), no significant difference was found between groups immediately and 30 second delaye curing of adhesive(P=0.748). mann whitney test showed significant difference between groups immediately and 2minutes delay placement of composite (P=0.002),and groups immediately and 5minutes delay placement of composite (P=0.001).there was no significant difference between groups with 2 and 5minutes delay in composite placement(P=0.815).
Conclusion: Delayed placement of composite increased micro leakage of class V composite restorations. there was no significant difference between 2 and 5 minutes delay placement of composite.30second delayed curing of adhesive had no significant difference on micro leakage, compared to immediately curing of it.
Maryam Modaber, Abd Rahim Davari, Sara Sayaf,
Volume 2, Issue 1 (1-2014)
Abstract
Background: Coronal fractures of permanent incisors represent 18-22% of all traumas to dental hard tissues. This investigation aimed to compare shear bond strength of fractured maxillary central teeth that incisal edge were restored by using different methods.
Methods: fifty-two human maxillary permanent central incisors were selected and divided into 3 experimental and 1 control groups. All the specimens in the experimental groups were sectioned from the incisal edge using diamond disk. Incisal fragments in first experimental group were rebounded with Panavia-F cement, in the second group at first incisal fragments were rebounded with Panavia-F and then bevel was performed on the reattachment line and then teeth were repaired with single bond adhesive and Z250 resin composite, in the third group incisal edge of all teeth were restored with Z250 composite resin utilizing its bonding agent (single bond). In the fourth group, intact teeth served as control. The maximum loads needed to break adhesive bond of reattached fragment were measured and then shear bond strength of every specimen was calculated. Statistical analysis was conducted by using Kruskal-wallis and Mann-whitney tests.
Results: The mean and Std.Deviation shear bond strengths were 2.21 MPa for group 1, 4.05 MPa for group 2, 3.69 MPa for group 3, and 29.62 MPa for group 4. There was a significant difference between the shear bond strength of different groups..
Conclusion: Reattachment of a fractured fragment with Panavia-F cement as well as bevel might be more preferable in cases of dental trauma.
