• Restorative Dentistry and Endodontics
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• v.30 no.1
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• pp.16-21
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• 2005

The purpose of present study was to compare the speed of coronal leakage before and after post space preparation using Streptococcus mutans. Forty straight extracted human teeth were selected. The crowns were removed to a uniform remaining root length 14 mm. Canals were enlarged by 06 taper $Profiles^{(R)}$ to a size $\#40$ as a master apical file. And these were filled with gutta percha point and $Tubuliseal^{(R)}$ sealer, using continuous wave technique. Groupings are as follows. Group 1 - These teeth were obturated without sealer. Group 2 - These teeth were obturated and covered the surface of the root completely with sticky wax. Group 3 - These teeth were obturated. Group 4 - These teeth were obturated and prepared for post space remaining 5 mm of gutta percha. The teeth were suspended in plastic tubes. The upper chamber received the bacterial suspension everyday to simulate clinical situation. The lower chamber consisted of BHI added Andrade's indicator. All roots in the positive control group (Group 1) turned yellow within 24 h and those of negative control group (Group 2) remained red throughout the experimental period (70 days) The samples of group 3 were contaminated within an average of 27.2 days. The samples of group 4 were contaminated within an average of 15.7 days, ranging from 9 to 22 days. There was significant difference between group 3 and group 4 statistically (p < 0.05).

• Restorative Dentistry and Endodontics
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• v.34 no.5
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• pp.383-389
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• 2009

The purpose of this study was to investigate the fracture resistance of crown-root fractured teeth repaired with dual-cured composite resin and horizontal posts. 48 extracted human premolars were assigned to control group and three experimental groups. Complete crown-root fractures were experimentally induced in all control and experimental teeth. In the control group. the teeth (n=12) were bonded with resin cement and endodontically treated. Thereafter, the access cavities were sealed with dual-cured composite resin. In composite resin core-post group (n=12), the teeth were endodontically treated and access cavities were sealed with dual-cured composite resin. In addition, the fractured segments in this group were fixed using horizontal posts. In composite resin core group (n=12), the teeth were endodontically treated and the access cavities were filled with dual-cured composite resin without horizontal posts. In bonded amalgam group (n = 12), the teeth were endodontically treated and the access cavities were sealed with bonded amalgam. Experimental complete crown-root fractures were induced again on repaired control and experimental teeth. The ratio of fracture resistance to original fracture resistance was analyzed with Kruskal-Wallis test. The results showed that teeth in control and composite resin core-post group showed significantly higher resistance to re-fracture than those in amalgam core group (p < 0.05). The resistance to refracture was high in the order of composite resin - post group, control group, composite resin group and bonded amalgam group. Within the scope of this study, the use of horizontal post could be beneficial in increasing the fracture resistance of previously fractured teeth.

• Journal of the korean academy of Pediatric Dentistry
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• v.46 no.1
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• pp.111-118
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• 2019

Post-endodontic restorations are both important and challenging for clinical success in endodontically treated posterior teeth. Several options have been proposed to restore endodontically treated molars. In pediatric dentistry, restoration using conventional single crowns, especially for partially erupted molars with insufficient retentive tooth structure, has proven to be difficult. However, the endocrown presents a conservative and esthetic restorative alternative to conventional crowns with post-and-core, as it acquires additional retention within the pulp chamber. The tooth preparation consists of a circular, equigingival, butt-joint margin and a central retention cavity in the pulp chamber that helps to construct both the crown and core as a single unit. This case report describes the esthetic and conservative endocrown restorations of erupting permanent first molars with extensive coronal destruction.