scholarly journals Fracture Resistance of Endodontically Treated Maxillary Premolars Restored by Various Direct Filling Materials: An In Vitro Study

2016 ◽  
Vol 2016 ◽  
pp. 1-5 ◽  
Author(s):  
Jozef Mincik ◽  
Daniel Urban ◽  
Silvia Timkova ◽  
Renata Urban
Keyword(s):  
Fracture Resistance ◽  
Endodontically Treated Teeth ◽  
Mean Values ◽  
Compression Load ◽  
Significant Difference ◽  
Group A ◽  
Maxillary Premolars ◽  
Group B ◽  
Group D

The aim of this study is to compare the effect of various restorative materials on fracture resistance in maxillary premolars. Premolars (n=64) with no restorations or cracks were selected. MOD cavities were prepared considering the buccolingual width to be equal to half of the intercuspal distance. The specimens were randomly divided into 8 groups, 8 specimens each:group Aintact teeth,group Bunfilled cavity,group Ccomposite made by oblique layering technique,group Dcomposite with 2 mm cusp coverage,group Ebulk-filled posterior composite,group Fglass-ionomer,group Gamalgam, andgroup Hcomposite with proximal boxes. The specimens were subjected to an axial compression load with the mean values of fracture resistance in group A: 1289 N, group B: 181.75 N, group C: 445.38 N, group D: 645.88 N, group E: 355.13 N, group F: 352.00 N, group G: 191.38 N, and group H: 572.00 N. There was no significant difference between groups B and G, between C and D, E, and F, and between group D and H. All other measurements were statistically significant. We conclude that composite restoration with cusp coverage is the most ideal nonprosthetic solution for endodontically treated teeth. Cusp coverage increases the fracture resistance compared to the conventional cavity design.

The Effect of Varying Ferrule Modes on Fracture Resistance of Canines Restored with One-Piece Milled Zirconia Post and Core

2012 ◽  
Vol 624 ◽  
pp. 98-102
Author(s):  
Yao Kun Zhang ◽  
Long Quan Shao ◽  
Ruo Yu Liu ◽  
Lin Lin Wang ◽  
Jun Ai ◽  
...  
Keyword(s):  
Fracture Resistance ◽  
In Vitro Study ◽  
Significant Difference ◽  
Zirconia Crowns ◽  
Group A ◽  
Post And Core ◽  
Resistance Decrease ◽  
Group B ◽  
Group D

The aim of this invitro study was to evaluate the fracture resistance of endodontically treated canines restored with one-piece milled zirconia post and core in the varying ferrule modes. Fifty recently extracted human maxillary canines were endodontically treated and randomly divided into 5 groups of 10 specimens each. According to the defect degree of ferrule, intact ferrule was classified as group A and served as control, 2 mm ferrule height without buccal ferrule was classified as group B, 2 mm ferrule height without mesial and buccal ferrule was classified as group C, 2 mm ferrule height without mesial, buccal and lingual ferrule was classified as group D, no ferrule preparation was classified as group E. All of the teeth were restored with one-piece milled zirconia post and core, and zirconia crowns. The teeth were prepared to standardized specifications. The restored teeth were loaded to fracture at a 135° angle to their long axis, at a cross-head speed 0.5 mm/min, and the load (N) at failure was recorded. Statistical analysis was performed by SNK pairwise multiple comparisons (α=0.05). The mean fracture resistance of five groups as follows: 1019.30±139.01N for group A, 861.20±105.67N for group B, 833.70±100.56N for group C, 733.20±96.91N for group D, 698.00±99.90N for group E. The fracture resistance of restored teeth between group B and group C, group D and group E had no statistically significant difference(P>0.05). The fracture resistance of the rest pairwise group comparisons had statistically significant difference(P<0.05). Increasing the absence degree of ferrule, it was found that the fracture resistance decrease. The buccal and lingual ferrule were more important than mesial ferrule for enhanced fracture resistance. This in vitro study supports evidence that reserving the buccal and lingual ferrule is a key point to increase the fracture resistance of canines restored with one-piece milled zirconia post and core.

Influence of Different Diameters and Materials of Posts on the Fracture Resistance of Endodontically Treated Teeth

2014 ◽  
Vol 633 ◽  
pp. 286-289
Author(s):  
Li Xian Zhang ◽  
Yu Xiao Liu ◽  
Ya Li Liu ◽  
Qiong Rong
Keyword(s):  
Fracture Resistance ◽  
Resistance Testing ◽  
Fiber Post ◽  
Endodontically Treated Teeth ◽  
Significant Difference ◽  
Group A ◽  
Group B ◽  
Different Diameters ◽  
Group D ◽  
Titanium Post

Objective: To evaluate the fracture resistance of endodontically treated teeth reinforced with cast titanium posts and prefabricated glass-fiber posts with different diameters. Materials and Methods: 50 recently extracted human maxillary central incisors were endodontically treated and randomly divided into 5 groups of 10 specimens each: Group A: 1.35mm diameter of cast titanium post; Group B: 1.5mm diameter of cast titanium post; Group C: 1.375mm diameter of prefabricated fiber post; Group D: 1.5mm diameter of prefabricated fiber post; Group E: resin restoration. All specimens were subjected to fracture resistance testing in a universal testing machine, statistical analysis was performed and the fracture modes were analyzed. Results: The mean fracture resistance of five groups as follows: 404.22±73.92N for group A, 488.17±78.68N for group B, 280.32±45.23N for group C, 317.53±50.87N for group D, 222.76±38.67N for group E. The fracture resistance of restored teeth between group C and group D had no significant difference (P>0.05). The fracture resistance of the rest pairwise group comparisons had significant difference (P<0.05). Most of cast post samples fractured at the root middle or apical portion, while most of the fiber post samples fractured at the root cervical or post fracture, which could be retreated. Conclusion: Human maxillary central incisors restored with cast posts could bear higher fracture load and fiber post could protect the root from fracture preferably.

scholarly journals Assessing Fracture Resistance of Restored Premolars with Novel Composite Materials: An In Vitro Study

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Zahraa Abdulaali Al-Ibraheemi ◽  
Huda Abbas Abdullah ◽  
Nada Abdlameer Jawad ◽  
Julfikar Haider
Keyword(s):  
Fracture Resistance ◽  
Testing Machine ◽  
In Vitro Study ◽  
Vitro Study ◽  
Resistance Testing ◽  
Significant Difference ◽  
Group A ◽  
Group B ◽  
Group D

During restorative treatment, premolars restored with resin filling materials using the conventional incremental-fill technique take longer restoration time and undermine the integrity of the tooth. The aim of this study was to assess fracture resistance of premolars restored by various types of novel bulk-fill composite resin materials. Forty-eight (n = 48) freshly extracted sound maxillary first premolars were used in this in vitro study. The teeth were divided into six groups, each having 8 specimens. Group A (positive control) was allocated for the intact teeth. For specimens in Groups B to F, a large cavity (Class-II MOD) was prepared with a standardized dimension of cavity (3 mm depth on the pulpal floor, 4 mm at the gingival seat, and 3 mm cavity width). Group B represented prepared teeth without any restoration. Group C, Group D, Group E, and Group F were restored with Tetric EvoCeram® incremental-fill (conventional), Beautifil bulk-fill, Filtek posterior bulk-fill, and SonicFill 2 bulk-fill restorative materials, respectively. All samples were finished and polished with an enhanced finishing kit and stored in distilled water for a month before the fracture resistance testing. All the samples were exposed to the axial loading (the speed of crosshead was 1 mm/min) in a computer-controlled universal testing machine (LARYEE, China) via a steel bar (6 mm in diameter) and the maximum applied force in Newton was recorded as the fracture resistance. One-way analysis of variance (SPSS 21) was used to compare the fracture resistance within the groups, and Tukey’s post hoc test was used to determine the difference between the groups. The lowest value of fracture resistance was recorded for Group B, and the highest value was recorded for Group A followed by the values of Group D, Group C, Group F, and Group E. One-way ANOVA revealed a statistically significant difference between the groups ( P < 0.05 ). Nonsignificant difference was found between the premolars restored by bulk-fill and conventional composites. Among the bulk-fill restored specimens, Beautifil restorative demonstrated significantly higher fracture resistance in comparison with the other two bulk-fill restored specimen groups (SonicFill 2 and Filtek). Bulk-fill composite such as Beautifil could be an alternative option to conventional incremental-fill composite for premolar restoration.

scholarly journals Efficacy of Palatal Applications on Fracture Resistance of Reattached Maxillary Central Incisors: AnIn VitroStudy

2017 ◽  
Vol 2017 ◽  
pp. 1-5
Author(s):  
İhsan Yikilgan ◽  
Nagihan Guven ◽  
Cemile Kedıcı Alp ◽  
Emre Tokar ◽  
Ozgur Topuz ◽  
...  
Keyword(s):  
Fracture Strength ◽  
Fracture Resistance ◽  
Composite Resin ◽  
In Vitro Study ◽  
Plane Normal ◽  
Fixed Distance ◽  
Group A ◽  
Group B ◽  
Group D

The purpose of this study was to evaluate the effects of different palatal applications on fracture strength of the fractured anterior tooth. Sixty caries-free human maxillary incisors were used. Endodontic treatments of the teeth were performed. Then, the teeth were divided randomly into five groups (n=12). Crowns of all teeth in groups A–D were cut with diamond discs at a fixed distance of 3 mm from the incisal margin in a plane normal to the buccal surface. In all groups, coronal fragments were reattached to the remaining teeth by bonding with hybrid composite resin. After then, the teeth were restored to the following; group A, bonding and palatal laminate; group B, bonding and creation of a vertical groove; group C, bonding and creation of two slot grooves; group D, bonding only; and group E, intact tooth. It was lesser in group B than in groups C and E (p=0.007andp=0.006, resp.) and lesser in group D than in groups A, C, and E (p=0.002,p<0.001, andp<0.001, resp.). Within the limitations of this in vitro study, it can be concluded that methods employing palatinal laminate and small grooves are clinically feasible for the reattachment of tooth fragments to incisors.

scholarly journals Base Materials’ Influence on Fracture Resistance of Molars with MOD Cavities

Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5242
Author(s):  
Gabriela Ciavoi ◽  
Ruxandra Mărgărit ◽  
Liana Todor ◽  
Dana Bodnar ◽  
Magdalena Natalia Dina ◽  
...  
Keyword(s):  
Fracture Resistance ◽  
Glass Ionomer Cement ◽  
Base Material ◽  
Glass Ionomer ◽  
Base Materials ◽  
Significant Difference ◽  
Group A ◽  
Group B ◽  
Group D ◽  
Ionomer Cement

The aim of this study was to compare fracture resistance of teeth presenting medium-sized mesial-occlusal-distal (MOD) cavities using different base materials. Thirty-six extracted molars were immersed for 48 h in saline solution (0.1% thymol at 4 °C) and divided into six groups. In group A, the molars were untouched, and in group B, cavities were prepared, but not filled. In group C, we used zinc polycarboxylate cement, in group D—conventional glass ionomer cement, in group E—resin modified glass ionomer cement, and in group F—flow composite. Fracture resistance was tested using a universal loading machine (Lloyd Instruments) with a maximum force of 5 kN and a crosshead speed of 1.0 mm/min; we used NEXYGEN Data Analysis Software and ANOVA Method (p < 0.05). The smallest load that determined the sample failure was 2780 N for Group A, 865 N for Group B, 1210 N for Group C, 1340 N for Group D, 1630 N for Group E and 1742 N for Group F. The highest loads were 3050 N (A), 1040 N (B), 1430 N (C), 1500 N (D), 1790 N (E), and 3320 N (F), the mean values being 2902 ± 114 N (A), 972 ± 65 N (B), 1339 ± 84 N (C), 1415 ± 67 N (D), 1712 ± 62 N (E), and 2334 ± 662 N (F). A p = 0.000195 shows a statistically significant difference between groups C, D, E and F. For medium sized mesial-occlusal-distal (MOD) cavities, the best base material regarding fracture resistance was flow composite, followed by glass ionomer modified with resin, conventional glass ionomer cement and zinc polycarboxylate cement. It can be concluded that light-cured base materials are a better option for the analyzed use case, one of the possible reasons being their compatibility with the final restoration material, also light-cured.

scholarly journals The Influence of Crown Ferrule on Fracture Resistance of Endodontically Treated Maxillary Central Incisors

2017 ◽  
Vol 21 (1) ◽  
pp. 44-49
Author(s):  
Sasho Jovanovski ◽  
Julie Popovski ◽  
Alesh Dakskobler ◽  
Ljubo Marion ◽  
Peter Jevnikar
Keyword(s):  
Fracture Resistance ◽  
Testing Machine ◽  
In Vitro Study ◽  
Resin Cement ◽  
Vitro Study ◽  
Endodontically Treated Teeth ◽  
Failure Patterns ◽  
Group A ◽  
Group B

SummaryBackground: Prefabricated zirconia posts can contribute to increasing the fracture resistance of the endodontically treated teeth. Purpose. This in vitro study compared the fracture resistance of endodontically treated central maxillary incisors prepared with 2 mm ferrule length to the ones without ferrule.Material and methods: Twenty-four caries-free maxillary central incisors were divided into 2 groups of 12. In group A circumferential external dentin shoulders were prepared for 2 mm external dentin ferrule length. There was no ferrule preparation in Group B. Zirconia VALLPOST BO-S (Ø 1,6 mm), Ljubljana, Slovenia were used with retention forms in the coronary part. Core build-up was made of pressed ceramics (IPS e.max Press, Ivoclar, Liechtenstein). Crowns were manufactured from the same ceramic material (IPS e.max Press, Ivoclar). After root canal treatment and post space preparation, all posts were cemented with an adhesive resin cement (Multilink Automix, Ivoclar). The specimens were embedded in acrylic resin blocks (ProBase Polymer/Monomer, Ivoclar) and loaded at an angle of 45° to the long axis in an Instron Testing Machine 4301 (Instron Corp., USA) at a crosshead speed of 1 mm/min until fracture. Fracture patterns and loads were recorded. A significance level of p<0.05 was used for all comparisons. Two-way analysis of variance was used for statistical analysis. Failure patterns were analyzed with the optical microscope Stereo Discovery V.8 (Carl Zeiss, Germany) and compared using the chi-square nonparametric test.Results: The mean values (±SD) of fracture loads (N) for the Groups A and B were 664.63N (±49.14) and 519.36N (±71.65) recpectively. Significantly lower failure loads were recorded for the specimens in the group B. Failure patterns within the groups revealed non-catastrophic failure in 70% of the specimens for group A and 85% for group B.Conclusions: Within the limitations of this in vitro study, it can be concluded that zirconia VALLPOST BO-S (Ø 1,6 mm) with press-ceramic cores and crowns, can be used for restoration of endodontically treated teeth. The teeth prepared with 2 mm external dentin ferrule length were found to be more fracture resistant than teeth without ferrule.

scholarly journals The Role of Obesity in Predicting the Clinical Outcomes of COVID-19

Obesity Facts ◽  
2021 ◽  
pp. 1-9
Author(s):  
Serdar Sahin ◽  
Havva Sezer ◽  
Ebru Cicek ◽  
Yeliz Yagız Ozogul ◽  
Murat Yildirim ◽  
...  
Keyword(s):  
Clinical Outcomes ◽  
Health Care Providers ◽  
Study Groups ◽  
Normal Weight ◽  
Overweight And Obesity ◽  
Care Providers ◽  
Significant Difference ◽  
Group A ◽  
Group B ◽  
Group D

<b><i>Introduction:</i></b> The aim of this was to describe the predictors of mortality related to COVID-19 infection and to evaluate the association between overweight, obesity, and clinical outcomes of COVID-19. <b><i>Methods:</i></b> We included the patients &#x3e;18 years of age, with at least one positive SARS-CoV-2 reverse transcriptase-polymerase chain reaction. Patients were grouped according to body mass index values as normal weight &#x3c;25 kg/m<sup>2</sup> (Group A), overweight from 25 to &#x3c;30 kg/m<sup>2</sup> (Group B), Class I obesity 30 to &#x3c;35 kg/m<sup>2</sup> (Group C), and ≥35 kg/m<sup>2</sup> (Group D). Mortality, clinical outcomes, laboratory parameters, and comorbidities were compared among 4 groups. <b><i>Results:</i></b> There was no significant difference among study groups in terms of mortality. Noninvasive mechanical ventilation requirement was higher in group B and D than group A, while it was higher in Group D than Group C (Group B vs. Group A [<i>p</i> = 0.017], Group D vs. Group A [<i>p</i> = 0.001], and Group D vs. Group C [<i>p</i> = 0.016]). Lung involvement was less common in Group A, and presence of hypoxia was more common in Group D (Group B vs. Group A [<i>p</i> = 0.025], Group D vs. Group A [<i>p</i> &#x3c; 0.001], Group D vs. Group B [<i>p</i> = 0.006], and Group D vs. Group C [<i>p</i> = 0.014]). The hospitalization rate was lower in Group A than in the other groups; in addition, patients in Group D have the highest rate of hospitalization (Group B vs. Group A [<i>p</i> &#x3c; 0.001], Group C vs. Group A [<i>p</i> &#x3c; 0.001], Group D vs. Group A [<i>p</i> &#x3c; 0.001], Group D vs. Group B [<i>p</i> &#x3c; 0.001], and Group D vs. Group C [<i>p</i> = 0.010]). <b><i>Conclusion:</i></b> COVID-19 patients with overweight and obesity presented with more severe clinical findings. Health-care providers should take into account that people living with overweight and obesity are at higher risk for COVID-19 and its complications.

scholarly journals Prophylactic temporary abdominal aortic balloon occlusion for patients with pernicious placenta previa: a retrospective study

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Fei Huo ◽  
Hansheng Liang ◽  
Yi Feng
Keyword(s):  
Placenta Previa ◽  
Balloon Occlusion ◽  
Artery Embolism ◽  
Abdominal Aortic ◽  
Significant Difference ◽  
Group A ◽  
Group B ◽  
Clinical Records ◽  
Group D ◽  
Central Placenta Previa

Abstract Background Pernicious placenta previa (PPP) can increase the risk of perioperative complications. During caesarean section in patients with adherent placenta, intraoperative blood loss, hysterectomy rate and transfusion could be reduced by interventional methods. Our study aimed to investigate the influence of maternal hemodynamics control and neonatal outcomes of prophylactic temporary abdominal aortic balloon (PTAAB) occlusion for patients with pernicious placenta previa. Methods This was a retrospective study using data from the Peking University People’s Hospital from January 2014 through January 2020. Clinical records of pregnant women undergoing cesarean section were collected. Patients were divided into two groups: treatment with PTAAB placement (group A) and no balloon placement (group B). Group A was further broken down into two groups: prophylactic placement (Group C) and balloon occlusion (group D). Results Clinical records of 33 cases from 5205 pregnant women underwent cesarean section were collected. The number of groups A, B, C, and D were 17, 16, 5 and 12.We found that a significant difference in the post-operative uterine artery embolism rates between group A and group B (0% vs.31.3%, p = 0.018). There was a significant difference in the Apgar scores at first minute between group A and group B (8.94 ± 1.43 vs 9.81 ± 0.75,p = 0.037),and the same significant difference between two groups in the pre-operative central placenta previa (29.4% vs. 0%,p = 0.044), complete placenta previa (58.8% vs 18.8%, p = 0.032),placenta implantation (76.5% vs 31.3%, p = 0.015). We could also observe the significant difference in the amount of blood cell (2.80 ± 2.68vs.10.66 ± 11.97, p = 0.038) and blood plasma transfusion (280.00 ± 268.32 vs. 1033.33 ± 1098.20, p = 0.044) between group C and group D. The significant differences in the preoperative vaginal bleeding conditions (0% vs 75%, p = 0.009), the intraoperative application rates of vasopressors (0% vs. 58.3%, p = 0.044) and the postoperative ICU (intensive care unit) admission rates (0% vs. 58.3%, p = 0.044) were also kept. Conclusions PTAAB occlusion could be useful in reducing the rate of post-operative uterine artery embolism and the amount of transfusion, and be useful in coping with patients with preoperative vaginal bleeding conditions, so as to reduce the rate of intraoperative applications of vasopressors and the postoperative ICU (intensive care unit) admission. In PPP patients with placenta implantation, central placenta previa and complete placenta previa, we advocate the utilization of prophylactic temporary abdominal aortic balloon placement.

scholarly journals Comparative Evaluation of Fracture Resistance of Endodontically Treated Teeth Restored with Resin Fiber Post and Stainless Steel Post: An In Vitro Study

2015 ◽  
Vol 03 (02) ◽  
pp. 080-084
Author(s):  
Vijay Singh ◽  
Poonam Bogra ◽  
Saurabh Gupta ◽  
Navneet Kukreja ◽  
Neha Gupta
Keyword(s):  
Stainless Steel ◽  
Fracture Resistance ◽  
Testing Machine ◽  
Compressive Force ◽  
Control Group ◽  
Fiber Post ◽  
Endodontically Treated Teeth ◽  
Group I ◽  
Significant Difference

AbstractFracture resistance of endodontically treated teeth restored with post. Aims: This study aims to compare the fracture resistance of endodontically treated teeth restored with resin fiber and stainless steel post. Commercially available prefabricated resin fiber post(Dentsply Maillefer Easy Post), prefabricated stainless steel post(Coltene/Whaledent Parapost) were used. Methods and Material: Forty five maxillary central incisors were obturated and divided into 3 groups: Control Group (Group I) without any post (n = 15), Resin Fiber Post Group (Group II) (n = 15) and Stainless Steel Post Group (Group III) (n = 15). In all Groups except control group, post space was prepared; a post was cemented, and a core build-up was provided. All the specimens were subjected to compressive force under a universal testing machine until fracture. Statistical analysis used: The results were analyzed using the variable analysis test (ANOVA). Results: One-way analysis of variance revealed significant difference among test groups. The control group demonstrated highest fracture resistance (925.2183 N), followed by the resin fiber post group (486.7265 N) and stainless steel post group (423.539N). Conclusions: Teeth restored with resin fiber post showed higher fracture resistance values than prefabricated stainless steel post.

scholarly journals Frictional Characteristics of the Newer Low-friction Elastomeric Ligatures

2016 ◽  
Vol 6 (1) ◽  
pp. 19-23
Author(s):  
Amol Mhatre ◽  
VK Ravindranath ◽  
Sachin Doshi ◽  
Girish Karandikar ◽  
PS Vivek
Keyword(s):  
Testing Machine ◽  
Frictional Resistance ◽  
Minimal Amount ◽  
New Delhi ◽  
Low Friction ◽  
Significant Difference ◽  
Group A ◽  
Group B ◽  
New Generation

ABSTRACT Aim The aim of this in vitro study was to investigate the efficiency of the new generation of elastomeric ligatures with innovative designs (SlideTM and AlastiKTM Easy-to-Tie) in reducing frictional resistance (FR) during sliding mechanics as compared with conventional ligatures. Materials and Methods Sixty ligature samples divided into four groups were used for the study. Group A: QuiK-StiK™ (3M Unitek, Monrovia, CA, USA), Group B: AlastiK™ Easy-to-Tie (3M Unitek, Monrovia, CA, USA), Group C: Slide™ (Leone, Firenze, Italy), and Group D: SS ligatures 0.010” (Libral Traders, New Delhi, India). Universal Testing Machine, Instron was used for measuring FR at the bracket-wire interface. Results There was statistically significant difference in FR among all the four groups of ligatures tested (p < 0.001). Slide ligatures produced the least amount of FR followed by SS ligatures, Easy-to-Tie, and QuiK-StiK in the increasing order of the FR values registered. Conclusion SlideTM ligatures may represent a valid alternative to passive self-ligating brackets when minimal amount of friction is desired. Angulation introduced into the elastomeric ligatures reduces the friction in comparison to conventional elastomeric ligatures. How to cite this article Vivek PS, Ravindranath VK, Karandikar G, Doshi S, Mhatre A, Sonawane M. Frictional Characteristics of the Newer Low-friction Elastomeric Ligatures. J Contemp Dent 2016;6(1):19-23.

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