scholarly journals Effect of cyclic loading on fracture strength of endodontically treated teeth restored with conventional and esthetic posts

2006 ◽  
Vol 14 (4) ◽  
pp. 297-303 ◽  
Author(s):  
Anuar Antônio Xible ◽  
Rudys Rodolfo de Jesus Tavarez ◽  
Carlos dos Reis Pereira de Araujo ◽  
Paulo César Rodrigues Conti ◽  
Wellington Cardoso Bonachella
Keyword(s):  
Survival Rate ◽  
Cyclic Loading ◽  
Fracture Strength ◽  
Resin Composite ◽  
Endodontically Treated Teeth ◽  
Core System ◽  
Group 3 ◽  
Post And Core ◽  
Group 2 ◽  
Group 1

INTRODUCTION: Esthetic post and core systems were recently introduced. There are few reports regarding their behavior under cyclic loading. OBJECTIVES: This study compared the effect of cyclic loading on survival rate, residual strength and mode of fracture of endodontically treated teeth restored with esthetic and direct metallic post systems subjected to mechanical cyclic loading. MATERIALS AND METHODS: Thirty canines were endodontically treated, decoronated and prepared for metal free ceramic crowns, leaving 1.5 mm of dentin for ferrule effect. They were distributed in 3 groups and restored as follows: group 1 with zirconia posts (Cosmopost) and glass-ceramic cores (IPS Empress Cosmopost); group 2 with fiber reinforced composite posts (FibreKor) and group 3 with titanium posts (AZthec Anchor). Direct resin composite (Build It FR Resin Composite) was used as core in groups 2 and 3. All specimens were restored with all ceramic crowns (IPS Empress 2). A resin cement/adhesive system (Cement It/Bond It Primer A+B) was used to lute the posts to root canals and metal free porcelain crowns to the teeth preparation. Specimens were subjected to mechanical load of 250 N for 500,000x at a frequency of 1.7 Hz and then to static load until failure in a universal testing machine. Data were analyzed using One-way ANOVA and Fischer Exact tests alpha=0.05. RESULTS: All groups had 100% survival rate after cyclic loading; fracture strength values (SD) in N were: group 1 = 886.5(170.6), group 2 = 762.2(113.6) and group 3 = 768.9(72.9); there was no difference among groups (p=0.08); the percentage of mode of favorable fracture found was: group 1 = 60%, group 2 = 90% and group 3 = 50%; there was no correlation between the mode of failure and post and core system used (P=0.142). CONCLUSIONS: Esthetic post and core systems showed statistically equivalent fracture strength values, mode of failure and survival rate compared to conventional direct metallic post and resin composite core system after cyclic loading.

The Effect of Fiber Dowel Heights in Resin Composite Cores on Restoration Failures of Endodontically Treated Teeth

2009 ◽  
Vol 35 (2) ◽  
pp. 63-69 ◽  
Author(s):  
Trakol Mekayarajjananonth ◽  
Nattinee Chitcharus ◽  
Sheldon Winkler ◽  
Meredith C. Bogert
Keyword(s):  
Fracture Resistance ◽  
Resin Composite ◽  
Endodontically Treated Teeth ◽  
Tooth Structure ◽  
Fiber Posts ◽  
Group 3 ◽  
Group 5 ◽  
Group 2 ◽  
Group 1

Abstract In vitro and in vivo testing suggest that fiber posts may reduce the incidence of root fractures of endodontically treated teeth. The purpose of this in vitro study was to compare the effect of fiber post height in resin composite cores on the fracture resistance of endodontically treated teeth. Forty maxillary central incisors were randomly divided into 2 control groups (Groups 1 and 2) of 5 teeth each, and 3 experimental groups (Groups 3, 4, and 5) of 10 teeth each. The teeth in Group 1 had their opening restored with composite resin, the teeth in Group 2 were restored with quartz fiber posts without resin composite cores, and the teeth in Groups 3, 4, and 5 were restored with quartz fiber posts of 2, 4, and 6 mm high, respectively, in 6-mm resin composite cores. Ceramic crowns were fabricated for the specimens. Specimens were positioned in a mounting device and aligned at a 130-degree angle to the long axis of each tooth. A universal testing machine was used to apply constant load at a crosshead speed of 0.5 mm/min until failure occurred. The highest fracture load and mode of failure of each specimen was recorded. The highest fracture resistance force was observed in Group 2 (290.38 ± 48.45 N) and decreased, respectively, in Group 1 (238.98 ± 26.26 N), Group 5 (228.35 ± 58.79 N), Group 4 (221.43 ± 38.74 N), and Group 3 (199.05 ± 58.00 N). According to one-way analysis of variance (ANOVA) and Duncan's test (P ≤ .05), there was no statistically significant increase in the force from Group 3 to Group 5, and the force in Group 2 was significantly higher than that of the experimental groups. There was no statistical significance difference in force among the experimental groups, and the amount of residual tooth structure was found to be the critical factor in fracture resistance. The results suggest that endodontically treated teeth should be restored with the longest possible post height while preserving maximum tooth structure.

Effect of Endocrowns on Fracture Strength and Microleakage of Endodontically Treated Primary Molar Teeth

2019 ◽  
Vol 10 (2) ◽  
pp. 113-119
Author(s):  
Tarek Seddik ◽  
Sera Derelioglu
Keyword(s):  
Fracture Strength ◽  
Compressive Loading ◽  
Class Ii ◽  
Control Group ◽  
Second Primary ◽  
Endodontically Treated Teeth ◽  
Primary Molar ◽  
Molar Teeth ◽  
Group 2 ◽  
Group 1

Objectives: Optimal restoration of endodontically treated teeth is very important for the durability of the endodontic treatment. The focus of this study was to evaluate the fracture strength and microleakage of composite endocrowns compared with Class II composite restorations in endodontically treated primary molar teeth. Materials and Methods: 48 extracted second primary molars were divided into 2 groups. Group 1 (control): teeth with Class II and endodontic access cavities restored with G-aenial composite; group 2: endocrown restorations with G-aenial composite. After completing restorative procedures, teeth were subjected to thermal cycling (500 cycles). Compressive loading was applied to half of the samples, although the other half were immersed in 0.5% basic fucsin solution for 24 h, sectioned, and examined for dye penetration under stereomicroscope. Data were subjected to statistical analysis by the Mann-Whitney U test (α = 0.05). Results: The fracture strength of endocrowns (1741 ± 379.35 N) was significantly higher than that of the control group (1126.5 ± 405.39 N) ( P < .05). No statistical difference was found in microleakage between the 2 groups ( P > .05). Conclusion: Endocrown preparation increases the fracture strength of the final composite restoration when used in primary molar teeth. Composite endocrown restorations can be a practical and an esthetic option for restoring endodontically treated primary molar teeth.

A Comparison of Arterial and Venous Flaps

1992 ◽  
Vol 17 (3) ◽  
pp. 359-364 ◽  
Author(s):  
S. P. CHOW ◽  
D. Z. CHEN ◽  
Y. D. GU
Keyword(s):  
Survival Rate ◽  
Elastic Properties ◽  
Perfusion Pressure ◽  
Skin Flap ◽  
Sprague Dawley ◽  
Venous Flaps ◽  
Sprague Dawley Rats ◽  
Group 3 ◽  
Group 2 ◽  
Group 1

The survival rate and elastic properties of the anterior abdominal skin flap in Sprague-Dawley rats were studied in three groups of animals. In group 1 where the flaps were supplied by a normal artery, arterial flaps (1A) had better survival rate and elastic properties than venous flaps (1B). In group 2, where the flaps were supplied by an artery with diminished perfusion pressure, the arterial flaps (2A) still had slightly better results than venous flaps (2B). However, in group 3 where the flaps were supplied by a vein, venous flaps (3B) had better results than arterial flaps (3A).

Creating Tight Proximal Contacts for MOD Resin Composite Restorations

2011 ◽  
Vol 36 (3) ◽  
pp. 304-310 ◽  
Author(s):  
MH Saber ◽  
W El-Badrawy ◽  
BAC Loomans ◽  
DR Ahmed ◽  
CE Dörfer ◽  
...  
Keyword(s):  
Resin Composite ◽  
Surface Group ◽  
Composite Restorations ◽  
Distal Surface ◽  
Composite Resin Restoration ◽  
Group 3 ◽  
Pressure Meter ◽  
Group 2 ◽  
Post Hoc ◽  
Group 1

SUMMARY Objective The purpose of this study was to compare proximal contact tightness (PCT) of MOD resin composite restorations placed with different matricing protocols. Methods Forty-five ivorine lower right first molars with standardized MOD cavities were equally divided into three groups according to the restoration protocol. Group 1: Sectional matrix (Standard matrix, Palodent, Dentsply) secured with a wedge (Premier Dental Products Co.) and separation ring (BiTine I, Palodent, Dentsply, York, PA, USA) was used to restore the mesial surface first and then removed and repeated for the distal surface. Group 2: Identical to group 1, but separation rings were placed at both the mesial and distal sides (BiTine I+II, Palodent) prior to restoration. Mesial surface was restored followed by distal. Group 3: Walser matrix (O-form, Dr. Walser Dental GmbH) was used. Following composite resin restoration, PCT was measured using the tooth pressure meter. Data were analyzed using analysis of variance and a Tukey post hoc test (p&lt;0.05). Results PCT values for mesial contacts were 2.99 ± 0.47N for group 1, 4.57 ± 0.36N for group 2, and 3.03 ± 0.79N for group 3. For the distal contacts, the values were 4.46 ± 0.44N for group 1, 5.12 ± 0.13N for group 2, and 0.76 ± 0.77N for group 3. Significantly tighter contacts were obtained for mesial and distal contacts for group 2 compared to groups 1 and 3 (p&lt;0.05). For groups 1 and 3, mesial contacts were not significantly different (p=0.993), while distal contacts for group 1 were significantly tighter (p&lt;0.001). Conclusion Within the limitations of this study, tighter contacts can be obtained when sectional matrices and separation rings are applied to both proximal surfaces prior to placement of the resin composite in MOD cavities.

scholarly journals Effect of the number of thermocycles on microleakage of resin composite restorations

2003 ◽  
Vol 17 (4) ◽  
pp. 337-341 ◽  
Author(s):  
Flávia Bittencourt Pazinatto ◽  
Bruno Barbosa Campos ◽  
Leonardo César Costa ◽  
Maria Teresa Atta
Keyword(s):  
Resin Composite ◽  
Control Group ◽  
Group 4 ◽  
Thermal Changes ◽  
Group 3 ◽  
Group 5 ◽  
Group 2 ◽  
Number Of Cycles ◽  
Group 1

Thermocycling simulates, in vitro, thermal changes that occur in the oral cavity. The aim of this study was to evaluate the influence of the number of cycles on microleakage. Class V cavities (1.5 mm deep, 3 mm in height and 3 mm in width) were prepared in bovine teeth, restored with a Single Bond/Z250 restorative system (3M/ESPE) and then divided into five groups of ten teeth each: group 1 was not thermocycled (control group), and groups 2, 3, 4 and 5 were thermocycled 500, 1,000, 2,500 and 5,000 times, respectively (5º-55º ± 2ºC, 15 s dwell time). The teeth were immersed in 0.5% basic fuchsin aqueous solution for 24 h, sectioned and the sections with the highest degree of microleakage were selected, scanned and the extent of dye penetration was measured by the ImageTool program. The results submitted to one-way ANOVA showed no significant differences between the groups (p > 0.05). The averages of microleakage values in millimeters were: group 1 (3.92); group 2 (3.13); group 3 (4.48); group 4 (4.33) and group 5 (3.42). Thus, it was concluded that there is no relation between the increase of the number of cycles and the increase in microleakage.

scholarly journals Results of neuroblastoma treatment in Lithuania: a single centre experience

2017 ◽  
Vol 24 (2) ◽  
pp. 128-137 ◽  
Author(s):  
Austėja Juškaitė ◽  
Indrė Tamulienė ◽  
Jelena Rascon
Keyword(s):  
Survival Rate ◽  
High Risk ◽  
Age At Diagnosis ◽  
Mycn Amplification ◽  
Disease Group ◽  
High Risk Patients ◽  
Risk Patients ◽  
Group 3 ◽  
Group 2 ◽  
Group 1

Background. Neuroblastoma (NB) is the most common extracranial solid tumour in children. This is a very rare disease with heterogeneous biology varying from complete spontaneous regression to a highly aggressive tumour responsible for 15% of malignancy-related death in early childhood. Analyses of survival rates in Europe have shown a considerable difference between Northern/Western and Eastern European countries. Treatment results of NB in Lithuania have never been analyzed. Aim. To assess the survival rate of children with NB according to initial spread of the disease, age at diagnosis, the MYCN amplification, risk group, and treatment period. Patients and methods. A retrospective single-centre analysis of patients’ records was performed. Children diagnosed and treated for NB between 2000 and 2015 at the Centre of Paediatric Oncology and Haematology of the Children’s Hospital, Affiliate of Vilnius University Hospital Santaros Klinikos were included. The patients were divided into three groups according to the spread of the disease: group 1 – patients with local NB older than 12 years of age; group 2 – stage IV patients, also called the M stage; group 3 – infants with stages 4S and MS. The patients were stratified into three risk groups – low, intermediate and high risk. Estimates of five-year overall survival (OS5y) were calculated using the Kaplan-Meier method comparing survival probability according to spread of the disease, age at diagnosis, the MYCN amplification, risk group and treatment period (2000–2007 vs 2008–2015). Results. Overall 60 children (31 girls and 29 boys) with NB were included. The median age at diagnosis was 1.87 years (ranged from 4 days to 15 years). Seventy-eight percent of cases were found to be differentiated or undifferentiated NB, 22% – ganglioneuroblastoma. The local form of the disease was predominant: 57% (34/60) of patients were allocated to the group 1, 37% (22/60) with initial metastatic disease were assigned to group 2, and infants with 4S or MS stage comprising 7% (4/60) allocated to group 3, respectively. The probability of OS5y for the entire cohort was 71% with the median follow-up of 8.8 ± 4.8 years. The probability of OS5y for local disease (group 1) was significantly higher compared to metastatic disease (group 2) (94% vs. 34%, p = 0.001, respectively) as well as for infants compared to children older than 12 months at the time of diagnosis (90% vs 60%, p = 0.009, respectively). The MYCN gene amplification had a negative influence on OS5y, with 78% of MYCN-negative patients surviving in comparison to 40% of MYCN-positive patients who did not survive (p = 0.153). The high-risk patients had significantly worse OS5y than children with intermediated or low risk (35% vs. 82% vs. 100%, respectively, p = 0.001). Comparison of OS5y between two treatment periods in the entire patient population revealed a non-significant increase in survival from 66% in the 2000–2007 period to 82% in the 2008–2015 period (p = 0.291), mostly due to a dramatic improvement achieved for high-risk patients whose survival rate increased from 9% in the 2000–2007 period to 70% in the 2008–2015 period (p = 0.009). Conclusions. There was a slight predominance of low-risk patients, probably due to a higher number of infants. A better probability of OS5y was confirmed in infants with local disease and in MYCN-negative patients. The OS5y for children treated for NB at our institution over 16 years increased from 66% in the 2000–2007 period to 82% in the 2008–2015 period with the most significant improvement achieved for high risk patients. The current survival rate of children treated for NB at our institution is in line with the reported numbers in Northern and Western European countries.

Influence of Cavity Preparation, Light-curing Units, and Composite Filling on Intrapulpal Temperature Increase in an In Vitro Tooth Model

2014 ◽  
Vol 39 (5) ◽  
pp. E195-E205 ◽  
Author(s):  
SH Choi ◽  
JF Roulet ◽  
SD Heintze ◽  
SH Park
Keyword(s):  
Resin Composite ◽  
The Other ◽  
Temperature Measurements ◽  
Group 4 ◽  
Light Curing ◽  
Group 3 ◽  
Group 2 ◽  
Power Densities ◽  
Group 1

SUMMARY This study examined the effect of both the tooth substance and restorative filling materials on the increase in pulp chamber temperature when using light-curing units with different power densities. The tip of a temperature sensor was positioned on the pulpal dentinal wall of the buccal side of a maxillary premolar. Metal tubes were inserted in the palatal and buccal root of the tooth, one for water inflow and the other for water outflow. Polyethylene tubes were connected from the metal tubes to a pump to control the flow rate. For the unprepared tooth group (group 1), the tooth was light-cured from the buccal side using two light-curing units (three curing modes): the VIP Junior (QTH, BISCO, Schaumburg, IL, USA) and the Bluephase LED light-curing units (two modes: LEDlow and LEDhigh; Ivoclar Vivadent, Schaan, Liechtenstein). The power densities of each light-curing unit for the LEDlow, QTH, and LEDhigh modes were 785 mW/cm2, 891 mW/cm2, and 1447 mW/cm2, respectively. All light-curing units were activated for 60 seconds. For the prepared tooth group (group 2), a Class V cavity, 4.0 mm in width by 4.0 mm in height by 1.8 mm in depth in size, was prepared on the buccal surface of the same tooth for the temperature measurement. The light-curing and temperature measurements were performed using the same methods used in group 1. The cavity prepared in group 2 was filled with a resin composite (Tetric N Ceram A3 shade, Ivoclar Vivadent) (group 3) or a flowable composite (Tetric N Flow with A3 shade, Ivoclar Vivadent) (group 4). The light-curing and temperature measurements were performed for these groups using the same methods used for the other groups. The highest intrapulpal temperature (TMAX) was measured, and a comparison was conducted between the groups using two-way analysis of variance with a post hoc Tukey test at the 95% confidence level. The TMAX values were as follows: 38.4°C (group 1), 39.0°C (group 2), 39.8°C (group 3), and 40.3°C (group 4) for the LEDlow mode. For the QTH mode, the TMAX values were 40.1°C (group 1), 40.4°C (group 2), 40.9°C (group 3), and 41.4°C (group 4). For the LEDhigh mode, the TMAX values were 43.3°C (group 1), 44.5°C (group 2), 44.7°C (group 3), and 45.3°C (group 4). The statistical analysis revealed the following: the TMAX values were arranged by mode in the following manner: LEDlow &lt; QTH &lt; LEDhigh (p&lt;0.05) and group 1 &lt; group 2 ≤ group 3 ≤ group 4 (p&lt;0.05).

scholarly journals Comparing the Effect of Different Management and Rearing Systems on Pigeon Squab Welfare and Performance after the Loss of One or Both Parents

Animals ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 165
Author(s):  
Azhar F. Abdel Fattah ◽  
El-Shimaa M. Roushdy ◽  
Hammed A. Tukur ◽  
Islam M. Saadeldin ◽  
Asmaa T. Y. Kishawy
Keyword(s):  
Survival Rate ◽  
Growth Performance ◽  
Foster Parent ◽  
Female Parent ◽  
Rearing Method ◽  
Group 3 ◽  
Group 2 ◽  
And Performance ◽  
Group 1

Pigeon squabs completely depend on their parents for care and nourishment. The loss of one or both parents affects squabs’ successful fledging. This study was carried out on young squabs to compare the effect of pigeon parent sex and different fostering methods on squab welfare (behavior and growth performance). Two experiments were carried out. In the first experiment, the squabs were divided into three groups. Group 1 (control) consisted of 10 parent pairs with 20 brooding squabs; group 2 consisted of 10 male parents with 20 brooding squabs; and group 3 consisted of 10 female parents with 20 brooding squabs. In the second experiment, the squabs were also divided into three groups. Group 1 (control) consisted of 10 parent pairs with 20 brooding squabs; group 2 consisted of 20 brooding squabs fostered by 10 foster parent pigeons (either male or female); and group 3 consisted of 20 brooding squabs fostered by the hand-rearing method. A significant improvement in growth performance, behavioral welfare (head waggle, squab note and squab wing shake); increased repetition of these behaviors indicates stress and discomfort), and survival rate was observed to be higher in the group brooded by both parents compared to the group brooded by either a male or a female parent. In addition, the group fostered by hand-rearing showed a significant improvement in growth performance, behavioral welfare, and survival rate compared to the group brooded by foster pigeon parents.

scholarly journals Influence of the remaining coronal structure on the resistance of teeth with intraradicular retainer

2005 ◽  
Vol 16 (3) ◽  
pp. 197-201 ◽  
Author(s):  
Jefferson Ricardo Pereira ◽  
Tatiany de Mendonça Neto ◽  
Vinícius de Carvalho Porto ◽  
Luiz Fernando Pegoraro ◽  
Accácio Lins do Valle
Keyword(s):  
Fracture Strength ◽  
Testing Machine ◽  
Acrylic Resin ◽  
Control Group ◽  
Coronal Structure ◽  
Endodontically Treated Teeth ◽  
Failure Data ◽  
Resin Core ◽  
Group 3 ◽  
Group 2

The aim of this study was to compare the resistance of endodontically treated teeth with intraradicular retainer different amounts of remaining coronal structure. Fifty freshly extracted maxillary canines were endodontically treated and randomly assigned to five groups (n=10), as follows: group 1 (control) = teeth with custom cast post and core; group 2 = teeth without remaining coronal structure; group 3, 4 and 5 = teeth with 1 mm, 2 mm and 3 mm of remaining coronal structure, respectively. All specimens in groups 2 to 5 were restored with prefabricated post and resin core. The teeth were embedded in acrylic resin and the fracture strength was measured on a universal testing machine at 45 degrees to the long axis of the tooth until failure. Data were analyzed statistically by one-way analysis of variance and Tukey's test. There was no significant differences (p>0.05) between the control group and group 2, and between groups 3, 4 and 5 (p>0.05). Control group and group 2 had significantly higher resistance strength than groups 3, 4 and 5 (p<0.00001). The findings of this study showed that teeth without remaining coronal structure had significantly higher fracture strength than those with remaining coronal structure (1 mm, 2 mm and 3 mm). When the dental crown was not completely removed, the amount of remaining coronal dentin did not significantly affect the fracture strength of endodontically treated teeth with intraradicular retainer.

scholarly journals In vitro evaluation of the fracture strength of all-ceramic core materials on zirconium posts

2013 ◽  
Vol 07 (04) ◽  
pp. 455-460 ◽  
Author(s):  
Nihal Ozcan ◽  
Erdal Sahin
Keyword(s):  
Fracture Strength ◽  
Test Group ◽  
Material Strength ◽  
All Ceramic ◽  
Cad Cam ◽  
Group 3 ◽  
Group 2 ◽  
Cerec 3D ◽  
Group 1

ABSTRACT Objective: For most endodontically treated teeth, tooth-colored post-core systems are preferable for esthetic reasons. Therefore, improvements in material strength must also consider tooth colored post-core complexes. The objective of this study was to evaluate the difference in tooth colored post-core complex strengths. Materials and Methods: A total of 33 human maxillary central incisor teeth were used for this study, with three groups of 11 teeth. Three different methods were used to fabricate all-ceramic post-core restorations: zirconia blanks, Cerec 3D-milled to one-piece post-core restorations (Test Group 1); feldspathic cores (from feldspathic prefabricated CAD/CAM blocks) adhesively luted to CosmoPost zirconia posts (Test Group 2); and IPS Empress cores directly pressed to CosmoPost zirconia posts (Test Group 3). All-ceramic crowns from feldspathic ceramic were constructed using a CAD/CAM system (Cerec 3D) for all specimens. The post-core complexes were tested to failure with the load applied at 45° angled relative to the tooth long axis. The load at fracture was recorded. Results: The maximum fracture strength of the milled zirconia cores (Test Group 1) was 577 N; corresponding values for the milled feldspathic cores (Test Group 2) and the pressed cores (Test Group 3) were 586 and 585 N, respectively. Differences were not statistically significant at P < 0.05 (P = 0.669). Conclusions: All-ceramic cores adhesively luted on zirconia posts and one-piece all-ceramic zirconium post-core structures offer a viable alternative to conventional pressing.

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