Kurumun Atıf Alan Makalesi
Atıf Alan Yayın
Evaluation of two post core systems using two different methods (fracture strength test and a finite elemental stress analysis)
Scopus
Toplam 193 atıf DOI
The aim of this study was to compare a fiber composite laminate (FCL) post core and a conventional cast post core system by using two different methods. The first method was a conventional fracture strength test, and the second was a finite elemental stress-analysis method (FEM). For the conventional fracture strength test, 20 extracted, human upper, central incisors were used. The teeth were decoronated, treated endodontically, and restored with two post core systems. After embedding the samples in resin blocks, a loading force was applied to the teeth at a crosshead speed of 5 mm/ min at an angle of 45 degrees to the long axis of the ooth. The data were recorded, and the results were compared by using the Mann-Whitney U test. There was no statistically significant difference between the two post systems (p>0.05). For FEM analysis, a pseudo three-dimensional model of a maxillary central incisor, theoretically restored with either a cast post or an FCL, was used. The analysis was performed by using the structural analysis program (SAP90). FEM analysis showed that stress was accumulated within the cast post core system, and transmission of stress to supportive structures and the tooth was low. This is an advantage for tooth and supporting tissues. When the FCL post core system was evaluated by FEM, the results indicated that this system transferr stress to supportive structures and the tooth while stress accumulation within the post system was low. This is an advantage for the restoration but disadvantage for the supporting tissues. Copyright © 2002 by The American Association of Endodontists.
Atıf Kaynağı
Atıf Yapan Yayın
Influence of several fibre-reinforced composite restoration techniques on cusp movement and fracture strength of molar teeth
Scopus
Havuzumuzda 40 atıf almış
Aim To compare mean cusp movement in molar teeth with endodontic access and mesial-occlusal-distal (MOD) cavities before and after restoration with several fibre-reinforced composite restoration techniques under loading and to evaluate the effect of restoration technique on fracture strength. Methodology Reference points were marked at the mesial cusp ridges of extracted human mandibular molar teeth. Digital images were taken under loading (300N) using a stereomicroscope (Leica MZ16A; Wetzlar, Germany). Three-dimensional (3D) distances between the reference points were recorded (Leica, Stereo-Explorer, 2.1) as controls. Standard MOD cavities were prepared and restored as follows (n=10), group 1: composite restoration (Clearfil AP-X; Kuraray, Tokyo, Japan); group 2: cavity lined with polyethylene fibre (Ribbond, Ribbond Inc., Seattle, WA, USA) in combination with flowable resin (Protect-Liner F; Kuraray, Tokyo, Japan) before composite restoration; group 3: polyethylene fibre inserted on occlusal surface of the tooth from buccal to lingual after finishing the composite restoration; group 4: missing walls were restored with composite resin and inner surfaces of the axial walls were then reinforced with polyethylene fibre placed circumferentially before the composite restoration. The restored teeth were re-loaded, digital images were re-taken and the 3D distance between the reference points was recorded in μm. Comparisons of the restoration techniques, the effectiveness of restoration for each group were analysed statistically (Kruskall-Wallis, paired-samples t-test). The teeth were then loaded until failure (5mmmin-1), the data were recorded (N) and analysed statistically (Kruskall-Wallis test). Results A significant difference occurred amongst the groups in terms of cusp movement (P=0.018). All the groups revealed a decrease in inter-cuspal width when compared to their initial records. The mean values of these decreases were as follows: group 1 17.6 (P=0.003), group 2 6.7 (not sig), group 3 6.6 (not sig) and group 4 0.85 (not sig) μm. No significant difference was found amongst the fracture strength values (P=0.22). In group 1, 90% of the fractures were non-restorable, whereas in group 3 100% of the fractures were restorable. Conclusions Regardless of restoration technique, fibre reinforcement of composite restorations decreased cusp movement in molar teeth with MOD and endodontic access cavities but did not affect fracture strength. © 2010 International Endodontic Journal.
Atıf Yapan Makale Bilgileri
Kurumlar (2)
Selçuk Üniversitesi
Selçuklu, Turkey
Van Yüzüncü Yıl Üniversitesi
Van, Turkey