Crystallite Size of Crown and Root Dentin from Vital and Endodontically Treated Teeth

2021 ◽  
Author(s):  
Ekaterina Karteva ◽  
Neshka Manchorova ◽  
Zhelyazko Damyanov ◽  
Ognyan Petrov ◽  
Stoyan Vladimirov
Keyword(s):  
Crystallite Size ◽  
Endodontically Treated Teeth ◽  
Root Dentin

scholarly journals Efficacy of Fiber Post Bonding To Root Dentin after Different Obturation Techniques and Cementation Timings: In Vitro Study

2018 ◽  
Vol 6 (9) ◽  
pp. 1707-1711
Author(s):  
Rami M. Atia ◽  
Nada Omar ◽  
Haidy Nabil ◽  
Yousra Aly
Keyword(s):  
Bond Strength ◽  
Statistical Significance ◽  
Testing Machine ◽  
In Vitro Study ◽  
Resin Cement ◽  
Vitro Study ◽  
Endodontically Treated Teeth ◽  
Root Dentin ◽  
Push Out

OBJECTIVE: The aim of this in vitro study was to assess the effect of obturation technique and cementation timings on the bonding of fibre-reinforced posts to the root canal walls. METHODS: Twenty extracted teeth were randomly allocated to two groups according to the obturation technique and cementation timing. Central incisors with single canals were used after being decoronated. Every extracted tooth of the {vertical compaction group} (VC) group (n = 10) had been obturated using the {E & Q plus obturation system} with posts cemented in the same day; The other (CO) conventional group (n = 10) teeth were obturated using the conventional lateral compaction technique and posts cemented after one week. “SF“ Fiber posts were used after bonding and cementation using Rely X ARC resin cement with all the endodontically treated teeth. The push-out test was performed in a universal testing machine. Data were analysed by 2 way analysis of variance with Statistical significance was set to 0.05. RESULTS: Heat softened gutta percha group showed more push out the bond strength of the bonded posts than the conventional obturation group (p < 0.05). In the middle region, there was no statistical significance between the two groups while there was significance in the coronal and apical thirds. CONCLUSION: The vertical compaction technique and early cementation improved the bond strength of the resin posts in comparison to the conventional obturation technique with late cementation.

Root dentin hardness of endodontically treated teeth

1981 ◽  
Vol 7 (9) ◽  
pp. 421-422 ◽  
Author(s):  
I. Lewinstein ◽  
R. Grajower
Keyword(s):  
Endodontically Treated Teeth ◽  
Root Dentin

scholarly journals Fracture resistance of endodontically treated teeth restored with resin post reinforced with glass fiber

2021 ◽  
Vol 14 (1) ◽  
pp. 81-85
Author(s):  
Mihaela Chirila ◽  
◽  
◽  
◽  
◽  
...  
Keyword(s):  
Glass Fiber ◽  
Fracture Resistance ◽  
Surface Friction ◽  
Axial Direction ◽  
Resin Cement ◽  
Resistance Testing ◽  
Endodontically Treated Teeth ◽  
Adhesive Resin ◽  
Gutta Percha ◽  
Root Dentin

This study aims to determine whether the design of resin posts reinforced with glass fiber (FRC) and Reporfost (Angelus, Londrina, PR, Brazil) significantly improves the fracture resistance of endodontically treated teeth restored through this method.A batch of 30 maxillary monoradicular teeth (15 central incisors, 15 canines) were treated endodontically by step-back technique (apical enlargement 40-K file) sealed with Sealapex (Kerr Corporation, Orange, US) and gutta-percha by lateral condensation, cold. They were divided into two equal groups, prepared for cementing the FRC posts. The Exacto posts (Angelus, Londrina, PR, Brazil) in group 1 and the Reforpost posts (Angelus; Londrina; PR, Brazil) were cemented with dual cure resin cement Breeze Self-Adhesive Resin Cement (Pentron Clinical, Orange, US). Fracture resistance testing was performed on the crown-apical axial direction, using the Hounsfield / Tinius Olsen H1-KS, PA, USA mechanical testing apparatus. The behavior of each tooth-post assembly was recorded as a graph. The statistical analysis was done using one way ANOVA (α=0.05). The differences between the Exacto post group and the Reforpost post group are not statistically significant (p = 0.466). The maximum force recorded was 970 N and the minimum 186N. The mean force at which the fracture occurred was approximately 500N for both groups. The strain test showed that modifying the Reforpost post design did not improve the fracture resistance parameters of the tooth-post assembly through increasing the surface friction or maintaining adhesion to the walls of the root dentin.

Age-related transparent root dentin: mineral concentration, crystallite size, and mechanical properties

Biomaterials ◽  
2005 ◽  
Vol 26 (16) ◽  
pp. 3363-3376 ◽  
Author(s):  
J.H. Kinney ◽  
R.K. Nalla ◽  
J.A. Pople ◽  
T.M. Breunig ◽  
R.O. Ritchie
Keyword(s):  
Mechanical Properties ◽  
Crystallite Size ◽  
Mineral Concentration ◽  
Age Related ◽  
Root Dentin

Collagen Degradation in Endodontically Treated Teeth after Clinical Function

2004 ◽  
Vol 83 (5) ◽  
pp. 414-419 ◽  
Author(s):  
M. Ferrari ◽  
P.N. Mason ◽  
C. Goracci ◽  
D.H. Pashley ◽  
F.R. Tay
Keyword(s):  
Structural Integrity ◽  
Zinc Phosphate ◽  
Bacterial Colonization ◽  
Collagenolytic Activity ◽  
Endodontically Treated Teeth ◽  
Collagen Matrices ◽  
Transmission Electron ◽  
The Status ◽  
Root Dentin

Endodontically treated teeth restored with posts are susceptible to coronal leakage after long-term function. We hypothesize that demineralized collagen matrices (DCMs) created in dentin by acidic zinc phosphate cement within the dowel spaces degrade with time. Forty-two post-restored teeth were extracted after three periods of clinical service and were examined, by means of scanning and transmission electron microscopy, for the status of the DCMs. SEM revealed a progressive degradation of the DCMs, becoming less dense after 3 to 5 years, losing structural integrity after 6 to 9 years, and partially disappearing after 10 to 12 years. TEM revealed evidence of collagenolytic activity within the DCMs, with loss of cross-banding and unraveling into microfibrils, and gelatinolytic activity that resulted in disintegration of the microfibrils. Bacterial colonization and the release of bacterial enzymes and of host-derived matrix metalloproteinases may contribute to the degradation of collagen fibrils in root dentin after clinical function.

Effects of Nd: YAG Laser Irradiation on the Adaptation of Composite Resins to Root Dentin

2005 ◽  
Vol 6 (4) ◽  
pp. 116-123 ◽  
Author(s):  
Murat Maden ◽  
Güliz Görgül ◽  
A. Cemal Tinaz ◽  
Bağdagül H. Kivanç ◽  
Özgür like Atasoy Ulusoy
Keyword(s):  
Laser Irradiation ◽  
Composite Resin ◽  
Alternative Therapy ◽  
Composite Resins ◽  
Acid Etching ◽  
Endodontically Treated Teeth ◽  
Human Teeth ◽  
Yag Laser ◽  
Root Dentin ◽  
Group 2

Abstract One of the most important goals of the restoration of endodontically treated teeth with a composite resin post system is to achieve good adaptation of the composite material to dentin walls to prevent microleakage apically and coronally. In post core systems, to avoid microleakage between the dentin wall and resin material, laser irradiation may seem to be an alternative therapy for increasing adaptation quality. The aim of this study was to investigate the adaptation of a packable composite resin to lased root canal dentin when it was used as post material. Forty-five freshly extracted human teeth were selected and post spaces were prepared. The teeth were divided into three groups. In group 1 the dentin of the post spaces were etched with 35% phosphoric acid, in group 2 the dentin surfaces were irradiated with an Nd: YAG laser, and in group 3 the dentin surfaces were initially treated with the laser and then etched. The teeth of all groups were obturated with a bonding agent and composite. The groups were divided into two subgroups: a group for the scanning electron microscope (SEM) study and a group for the microleakage study. The lased group showed poor adaptation and more microleakage was detected (p<0.05; variance analysis). The laser beam and acid-etching showed no advantage compared to the acid-etching alone (p>0.05). The Nd: YAG laser irradiation adversely affects adhesion to dentin for using composite resin as a post material and does not constitute an alternative to acid-etching. Citation Görgül G, Kivanç BH, Maden M, Ulsoy ÖLA, Tinaz AC. Effects of Nd: YAG Laser Irradiation on the Adaptation of Composite Resins to Root Dentin. J Contemp Dent Pract 2005 November;(6)4:116-123.

Direct Observation of Crystalline Ordering In Naturally Graphitized Carbon Produced by Low Grade Metamorphism

1977 ◽  
Vol 35 ◽  
pp. 162-163
Author(s):  
Thomas R. McKee ◽  
Peter R. Buseck
Keyword(s):  
Crystallite Size ◽  
Sedimentary Rocks ◽  
Carbonaceous Material ◽  
Low Grade ◽  
X Ray ◽  
Graphitized Carbon ◽  
Transmission Electron ◽  
Heat Treated ◽  
Commercial Carbon ◽  
Metamorphic Zone

Sediments commonly contain organic material which appears as refractory carbonaceous material in metamorphosed sedimentary rocks. Grew and others have shown that relative carbon content, crystallite size, X-ray crystallinity and development of well-ordered graphite crystal structure of the carbonaceous material increases with increasing metamorphic grade. The graphitization process is irreversible and appears to be continous from the amorphous to the completely graphitized stage. The most dramatic chemical and crystallographic changes take place within the chlorite metamorphic zone.The detailed X-ray investigation of crystallite size and crystalline ordering is complex and can best be investigated by other means such as high resolution transmission electron microscopy (HRTEM). The natural graphitization series is similar to that for heat-treated commercial carbon blacks, which have been successfully studied by HRTEM (Ban and others).

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