scholarly journals An evaluation of the effect of different veneer materials on fracture resistance of zirconia core

2021 ◽  
Vol 24 (3) ◽  
Author(s):  
Yousra Abdulkareem Ibraheem ◽  
Zahraa Nazar Alwahab

Objective: this in vitro study was done to evaluate  the effect of packable P60 composite and Tetric N-Ceram composite veneer material on fracture strength of zirconia cores. Material and Methods:  Twenty four zirconium cores (Vita, Germany) with 0.7 mm thickness were fabricated by CAD/CAM technology and then subjected to air abrasion with 50µm of Al2O3. Cores were randomly divided into three groups according to veneering material (group A: control group sandblasted with 50 µm Al2O3 veneered by IPS E-max Ceram porcelain, group C: sandblasted with 50 µm Al2O3,  etching with hydrofluoric acid and veneered with P60 composite, group E: sandblasted with 50 µm Al2O3, etching with hydrofluoric acid and veneered with Tetric N-Ceram composite). All crowns were subjected to fracture strength test in the testing machine, with load application by steel ball indenter and 0.5 mm/min. cross head speed. Results: statistical analysis was carried out utilizing one-way ANOVA, LSD. The results of fracture strength value test showed the highest mean value was registered for group (A), and the lowest mean for group (E). One-way ANOVA test represented that, there was a statistically high significant different among all groups. LSD results  showed a high significant difference increase in fracture resistance for Group A at p value (*P<0.001 High significant). Conclusions: Within the limitation of this study, sandblasting zirconia core with 50 µm Al2O3 and veneering with conventional ceramic produced restoration with acceptable fracture resistance value.   Keywords Composite resin; Fracture resistance; Hydrofluoric acid; IPS Emax ceram; zirconium oxide.

2021 ◽  
Author(s):  
Ensieh Grayli ◽  
Abbas Dashtban ◽  
Leyla Shadan ◽  
Naser Behnampour ◽  
Elham Afshari

Abstract Background: Endodontically treated immature teeth which are restored with cast metal posts are of the most susceptible teeth to fracture. An apical plug is usually used as root end filling in order to seal the wide apical foramen. The current study was performed to evaluate the effect of different root-end filling materials (MTA and CEM) on fracture resistance of teeth restored with cast metal posts.Methods: A total of 40 extracted intact single-rooted human mandibular premolars (removed for orthodontic reasons) were used in the study. The coronal part of each tooth was removed and root canal preparation was performed. A size 4 Gates Glidden drill was used to enlarge the canal and was passed through the apical foramen in order to simulate an immature apex. Samples were randomly divided into 5 groups according to apical plug (Group 1: No plug, Group 2: 5 mm MTA plug, Group 3: 5 mm CEM plug, Group 4: 2 mm MTA plug, Group 5: 2 mm CEM plug). Post-space preparations were performed and cast metal post-and-cores were fabricated and cemented. Fracture resistance was assessed using a universal testing machine. Fracture thresholds were recorded and data were analyzed using SPSS 16.0 with significance level at P value < 0.05. Results The analysis showed a significant difference of fracture resistance between groups (p-value<0.05). The mean fracture resistance of samples in group 1 was significantly lower than group 2 (p-value=0.003). there was no significant difference between other groups (p-value>0.05).Conclusions: Within the limits of this study, the evidence indicated that placement of a 5 mm MTA apical plug increased the fracture resistance in simulated immature teeth which are restored with cast metal posts, compared to control group (gutta-percha and sealer). While the results were not as promising for a 2 mm MTA apical plug or either 2 or 5 mm CEM apical plug.


2015 ◽  
Vol 03 (02) ◽  
pp. 080-084
Author(s):  
Vijay Singh ◽  
Poonam Bogra ◽  
Saurabh Gupta ◽  
Navneet Kukreja ◽  
Neha Gupta

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.


Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 436
Author(s):  
Lucía Barallat ◽  
María Arregui ◽  
Sandra Fernandez-Villar ◽  
Blanca Paniagua ◽  
Andrés Pascual-La Rocca

There is ample evidence to support the use of endocrowns to restore endodontic teeth. However, the influence of the position of the interproximal margins on fracture strength has not yet been studied. The aim was to determine the relationship between the apicocoronal position of the interproximal restorative margins and fracture resistance in nonvital teeth restored with CAD/CAM endocrown overlays. Forty extracted human maxillary premolars were prepared for endocrown overlay restorations without ferrule on the interproximal aspects and classified according to the position of the interproximal restoration margins in relation to the alveolar crest: 2 mm (group A), 1 mm (group B), 0.5 mm (group C), and 0 mm (group D). Fracture strength was measured using a universal testing machine applying a compressive force to the longitudinal tooth axis. Group A had a mean fracture resistance of 859.61 (±267.951) N, group B 1053.9 (±333.985) N, group C 1124.6 (±291.172) N, and group D 780.67 (±183.269) N, with statistical differences between groups. Group C had the highest values for fracture strength compared to the other groups (p < 0.05). The location of the interproximal margins appears to influence the fracture resistance of CAD/CAM endocrown overlays. A distance of 0.5 mm between the interproximal margin and the alveolar crest was associated with increased fracture resistance.


2018 ◽  
Vol 43 (2) ◽  
pp. 162-169 ◽  
Author(s):  
ME Hshad ◽  
EE Dalkılıç ◽  
GC Ozturk ◽  
I Dogruer ◽  
F Koray

SUMMARY Objective: The purpose of this study was to determine the fracture strength of endodontically treated mandibular premolar teeth restored with composites and different reinforcement techniques. Methods and Materials: Forty-eight freshly extracted human mandibular premolar teeth were randomly divided into four groups: group IN, group CR, group FRC, and group PRF. Group IN consisted of teeth with intact crowns and served as the control group. In the other three groups, endodontic treatment was performed and standard mesio-occluso-distal (MOD) cavities were prepared. Then cavities were restored with hybrid resin composite only, flowable composite and hybrid resin composite, and Ribbond, flowable composite and hybrid resin composite in groups CR, FRC and PRF, respectively. All of the teeth were subjected to fracture by means of a universal testing machine, and compressive force was applied with a modified stainless-steel ball at a crosshead speed at 0.5 mm/min. Results: The highest values were observed in group IN, while the lowest values were determined in group CR. There was not any statistically significant difference between group CR and group FCR (p&gt;0.05). When groups CR, FCR, and PRF were compared, group PRF showed significantly better fracture strength than did groups CR and FCR (p&lt;0.05). It was determined that there was not any significant difference between group IN and group PRF (p&gt;0.05). Conclusions: Polyethylene ribbon fiber considerably increases the fracture strength of mandibular premolar teeth with MOD cavities restored with composite.


2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Baraba Anja ◽  
Dukić Walter ◽  
Chieffi Nicoletta ◽  
Ferrari Marco ◽  
Sonja Pezelj Ribarić ◽  
...  

The purpose of thisin vitrostudy was to evaluate the microtensile bond strength of one-step self-etch adhesive to human dentin surface modified with air abrasion and sonic technique and to assess the morphological characteristics of the pretreated dentin surface. The occlusal enamel was removed to obtain a flat dentin surface for thirty-six human molar teeth. The teeth were randomly divided into three experimental groups (n= 12 per group), according to the pretreatment of the dentin: (1) control group, (2) air abrasion group, and (3) sonic preparation group. Microtensile bond strength test was performed on a universal testing machine. Two specimens from each experimental group were subjected to SEM examination. There was no statistically significant difference in bond strength between the three experimental groups (P> 0.05). Mean microtensile bond strength (MPa) values were 35.3 ± 12.8 for control group, 35.8 ± 13.5 for air abrasion group, and 37.7 ± 12.0 for sonic preparation group. The use of air abrasion and sonic preparation with one-step self-etch adhesive does not appear to enhance or impair microtensile bond strength in dentin.


2019 ◽  
Vol 26 (08) ◽  
pp. 1272-1277
Author(s):  
Madiha Maryam ◽  
Muhammad Kashif ◽  
Abdul Ghafoor Sajjad ◽  
Razia Rizwan ◽  
Sehrish Ali ◽  
...  

To compare the effect of posterior capsular stretch on pain, ROM and functional disability in Adhesive Capsulitis. Study Design: Experimental, Randomized Control Trail. Setting: Department of Physiotherapy, Capital Development Authority Hospital Islamabad. Period: October 2015 to March 2016. Materials and Methods: Forty female patients having aged between 40 to 70 years with freezing and frozen stage of adhesive capsulitis were screened out. Adhesive capsulitis secondary to cervical Spondylosis, osteoporosis, direct trauma and any inflammation were excluded from the study. Subjects were randomly placed into two groups lottery method, the experimental group having 19 subjects received posterior capsular stretch along with conventional manual therapy and electrotherapy  whereas the control group had 21 subjects and they were given manual therapy and electrotherapy alone. The Numeric Pain Rating Scale, Shoulder Pain and Disability Index, and Range of Motion of shoulder joint were used as outcome measures. All the patients were assessed at baseline before intervention and at the completion of 6 weeks of treatment. Data was analyzed using SPSS version 20. Results: Abduction, Internal Rotation and disability show significant result. The abduction mean value of Group A was 115.00±22.023and of the Group B was 81.74±20.653 with p value was P<05. The internal rotation mean value of Group A was 70.71±12.776 and for the Group B was 60.32±8.699 and having p value P<05. The SPADI mean value of Group A was 51.76±22.043 and for the Group B was 24.24±7.287 having p value P<05. The NPRS and external rotation showed non-significant difference. Conclusion: It is concluded that posterior capsular stretch along with mobilization is more effective in treating ROM and functional disability.


Author(s):  
Shahram Mosharrafian ◽  
Maryam Shafizadeh ◽  
Zeinab Sharifi

Objectives: This study aimed to compare the fracture resistance of a bulk-fill and a conventional composite and a combination of both for coronal restoration of severely damaged primary anterior teeth. Materials and Methods: In this in vitro experimental study, 45 primary anterior teeth were randomly divided into three groups. After root canal preparation, the canals were filled with Metapex paste such that after the application of 1 mm of light-cure liner, 3 mm of the coronal third of the canal remained empty for composite post fabrication. Filtek Z250 conventional composite was used in group 1, Sonic-Fill bulk-fill composite was used in group 2 and Sonic-Fill with one layer of Filtek Z250 as the veneering were used in group 3. Adper Single Bond 2 was used in all groups. The teeth were thermocycled, and fracture resistance was measured by a universal testing machine. The mode of fracture was categorized as repairable or irreparable. Data were analyzed using one-way ANOVA. Results: The mean fracture resistance was 307.00±74.72, 323.31±84.28 and 333.30±63.96 N in groups 1 to 3, respectively (P=0.55). The mean fracture strength was 14.53±2.98, 15.08±2.82 and 15.26±3.02 MPa in groups 1 to 3, respectively (P=0.77). The frequency of repairable mode of failure was 80% for the conventional, 73.6% for the bulk-fill and 80% for the bulk-fill plus conventional group, with no significant difference (P>0.05). Conclusions: Bulk-fill composites can be used for coronal reconstruction of severely damaged primary anterior teeth similar to conventional composites to decrease the treatment time in pediatric patients.


2021 ◽  
Vol 19 (1) ◽  
pp. 27-30
Author(s):  
Y Satish Reddy ◽  

Background: Interactive Teaching learning can be used in clinical subjects like surgery for better participation of students as one-way didactic lectures do not involve active participation of students. WhatsApp is one of the most famous messaging services which everyone use and it is easy, cheaper, and faster. Objective: the purpose of the study was to study the impact of whatsapp in improving learning in general surgery among 9th semester medical students. Methods: This study was conducted among 9th semester MBBS students in Surgery department. Students were divided into group a (study group) and group b(control group) by a simple random sampling. Gastric cancer was discussed among students of both Groups through didactic teaching. after didactic teaching, only Group A students were exposed to social media type of learning, i.e., using WhatsApp, after the session a multiple-choice questionnaire having 10 MCQs was given to both groups and an additional poll was conducted among the Study-group students to assess their perception towards Whatsapp intervention. the mean score obtained by both the groups were compared with unpaired t test. P-value <0.05 is taken as statistically significant. Results: The mean (SD) score of the Study-group was 8.58(1.18) and the mean (SD) score of the Control-group was 5.41(1.32) and statistically significant difference was found between the two groups scores with a p-value less than 0.05 opinion poll found that the intervention of whatsapp among study group was effective. Conclusion: we observed that the usage of WhatsApp in addition to the didactic teaching was found advantageous and enhanced learning in undergraduate students


2017 ◽  
Vol 41 (4) ◽  
pp. 280-283 ◽  
Author(s):  
Pallavi Hasija ◽  
Vinod Sachdev ◽  
Shivani Mathur ◽  
Rishi Rath

Objective: The aim of this study was to compare the effect of different deproteinizing agents on shear bond strength of composite to primary teeth enamel. Study Design: Forty sound primary molars divided in 4 groups of 10 teeth each. In control group 1, enamel was etched for 60 seconds with 37% phosphoric acid and rinsed with water. Group 2: after acid etching deproteinizing agent 5 % sodium hypochlorite was applied for 60 seconds and rinsed. Group 3: after acid etching deproteinizing agent papain gel was applied for 60 seconds and rinsed. Group 4: after acid etching deproteinizing agent bromelain gel applied for 60 seconds and rinsed. Following this, bonding agent was applied to treated enamel surface and composite resin disc were build. Samples were then tested for shear bond strength using Universal Testing Machine. Results: Mean SBS was highest for group 4 and lowest for group 1. No statistically significant difference (p value &gt;0.05) was found between all the four groups. Conclusion: Among deproteinizing agents, deproteinization when carried out with bromelain gel and sodium hypochlorite showed effective bond strength as compared to papain.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Ensieh Grayli ◽  
Abbas Dashtban ◽  
Leyla Shadan ◽  
Naser Behnampour ◽  
Elham Afshari

Abstract Background Endodontically treated immature teeth which are restored with cast metal posts are of the most susceptible teeth to fracture. An apical plug is usually used as root end filling in order to seal the wide apical foramen. The current study was performed to evaluate the effect of different apical plug materials (MTA and Calcium enriched mixture cement) at varied thicknesses on fracture resistance of teeth restored with cast metal posts. Methods A total of 40 extracted intact single-rooted human mandibular premolars (removed for orthodontic reasons) were used in the study. The coronal part of each tooth was removed and root canal preparation was performed. A size 4 Gates Glidden drill was used to enlarge the canal and was passed through the apical foramen in order to simulate an immature apex. Samples were randomly divided into 5 groups (n = 8) according to apical plug (control group: No plug, group MTA5: 5 mm MTA plug, group CEM5: 5 mm CEM plug, group MTA3: 3 mm MTA plug, group CEM3: 3 mm CEM plug). Post-space preparations were performed and cast metal post-and-cores were fabricated and cemented. Fracture resistance was assessed using a universal testing machine. Fracture thresholds were recorded and data were analyzed using One-way ANOVA and Dunnett’s T3 tests with significance level at P value < 0.05. Results The analysis showed a significant difference of fracture resistance between groups (P value < 0.05). The mean fracture resistance of samples in control group was significantly lower than MTA5 (P value = 0.003). There was no significant difference between other groups (P value > 0.05). Conclusions Within the limits of this study, the evidence indicated that placement of a 5 mm MTA apical plug increased the fracture resistance in simulated immature teeth which are restored with cast metal posts, compared to control group (gutta-percha and sealer). While the results were not as promising for a 3 mm MTA apical plug or either 3 or 5 mm CEM apical plug.


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