scholarly journals Influence of Sealing of the Screw Access Hole on the Fracture Resistance of Implant-Supported Restorations

2016 ◽  
Vol 27 (2) ◽  
pp. 148-152 ◽  
Author(s):  
Rodrigo de Paula Pereira ◽  
Cibele Oliveira de Melo Rocha ◽  
José Maurício dos Santos Nunes Reis ◽  
João Neudenir Arioli-Filho
Keyword(s):  
Fracture Resistance ◽  
Resin Composite ◽  
Filling Material ◽  
Ceramic Surface ◽  
Access Hole ◽  
Mandibular Molar ◽  
Significant Difference ◽  
Metal Ceramic ◽  
One Way Anova ◽  
Ceramic Implant

Abstract The purpose of this study was to assess the influence of sealing of the screw access hole (SAH) on the fracture resistance of metal-ceramic implant-supported restorations. UCLA abutments were used to make 30 implant-retained mandibular molar restorations and divide equally into three groups: Group SRS: screw-retained restorations with SAH sealed; Group SRNS: screw-retained restorations with SAH not sealed; Group CR: cement-retained restorations. The following protocol was adopted to restore the SAH: the ceramic surface of the SAH was air-abraded with aluminum oxide; etched with 10% hydrofluoric acid; a silane coupling agent and a bonding agent were applied; cotton pellets were used as filling material and P-60 resin composite as restoring material. The cement-retained restorations were cemented with Rely-X U100. A metal rod with a spherical tip of 6.0 mm diameter was used to apply a vertical static load, simultaneously on the buccal and lingual incline cusps, at a crosshead speed of 0.5 mm/min until the fracture of the specimens. Data were analyzed using one-way ANOVA and Dunnet test (p<0.05) for multiples comparisons. The mode of failure was evaluated by a scanning electron microscopy (SEM). No significant difference between screw-retained restorations was found. The highest mean fracture resistance values were observed with CR group. Therefore, it was shown that SAH sealing did not influence the fracture resistance of the screw-retained restorations.

Fracture Resistance and Marginal Adaptation of Capped and Uncapped Bulk-fill Resin-based Materials

2020 ◽  
Vol 45 (2) ◽  
pp. E43-E56
Author(s):  
HN Al-Nahedh ◽  
Z Alawami
Keyword(s):  
Fracture Resistance ◽  
Resin Composite ◽  
Testing Machine ◽  
High Viscosity ◽  
Significance Level ◽  
Capping Layer ◽  
Composite Restorations ◽  
Significant Difference ◽  
Light Curing ◽  
One Way Anova

SUMMARY Objectives: This study tested the fracture resistance of capped and uncapped bulk-fill composite restorations and compared them to a conventional composite. Also, the effect of different radiant exposure was investigated. Methods and Materials: Flowable and high-viscosity bulk-fill composites (SureFil SDR, Filtek Bulk-Fill Posterior, and Tetric N-Ceram Bulk-Fill) and a nanohybrid resin composite (Filtek Z350 XT) were used. Standardized class II cavities were prepared on extracted premolars, and different restoration protocols were used. In protocol 1 (control), restoration was applied using a layering technique; in protocol 2, restoration was applied in bulk with a capping layer; in protocol 3, restoration was applied in bulk without a capping layer; and in protocol 4, restoration was applied in bulk without a capping layer, and the light curing time was extended. After thermocycling, the restorations were examined for marginal gaps and then subjected to the fracture resistance test using a universal testing machine. Statistical analysis was carried out using two-way analysis of variance (ANOVA) followed by one-way ANOVA at a significance level of α = 0.05. Results: A statistically significant difference in the fracture resistance of the tested materials and protocols was detected. Filtek Bulk-Fill Posterior achieved the highest fracture resistance values regardless of the protocol used, and its results were comparable to those of Filtek Z350. SDR and Tetric N-Ceram Bulk-Fill achieved their highest strengths when a capping layer was added. Tetric N-Ceram Bulk-Fill showed improvement in fracture resistance with extended light curing, while SDR and Tetric N-Ceram Bulk-Fill achieved similar results with the addition of a capping layer. The uncapped bulk-fill group showed more gap-free margins than the capped group. Conclusion: The new high-viscosity bulk-fill composite restorations seem to have adequate fracture resistance. However, the results are material dependent, and some materials perform better with a capping layer and extended light curing.

scholarly journals Effect of Incisal Porcelain Veneering Thickness on the Fracture Resistance of CAD/CAM Zirconia All-Ceramic Anterior Crowns

2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Noha Badran ◽  
Sanaa Abdel Kader ◽  
Fayza Alabbassy
Keyword(s):  
Fracture Resistance ◽  
Testing Machine ◽  
Mode Iii ◽  
Nickel Chromium ◽  
Significant Difference ◽  
All Ceramic ◽  
Metal Ceramic ◽  
Cad Cam ◽  
Ceramic Crown

Statement of Problem. In some clinical situations, the vertical length of either a prepared tooth or an implant abutment is short, while the occlusal clearance to be restored by a porcelain crown is large. Incisal thickness of the veneering porcelain should be considered to prevent mechanical failure of the crown. Purpose. The aim of this study is to evaluate the effect of two different incisal veneering porcelain thickness on the fracture resistance of the anterior all-ceramic CAD/CAM zirconia crown system as compared with the conventionally used metal ceramic crown system. Method. CAD/CAM zirconia all-ceramic and metal ceramic crowns were fabricated on the prepared dies with standardized dimensions and designs using standardized methods according to the manufacturer’s instructions. All crowns were then adhesively luted with resin-based cement (Multilink cement system), subjected to thermal cycling and cyclic loading, and were loaded until fracture using the universal testing machine to indicate the fracture resistance for each crown material in each veneering thickness. Results. Statistical analysis was carried out, and the results showed that the fracture resistance of the nickel-chromium metal ceramic group was significantly higher than that of the CAD/CAM zirconia all-ceramic group. Also, the fracture resistance of crowns with 1.5 mm incisal veneering thickness was significantly higher than those with 3 mm incisal veneering thickness in both groups. Furthermore, there was no significant difference in the fracture mode of the two groups where 50% of the total specimens demonstrated Mode II (veneer chipping), while 35% demonstrated Mode I (visible crack) and only 15% demonstrated Mode III (bulk fracture). Conclusion. High failure load values were demonstrated by the specimens in this study, which suggest sufficient strength of both incisal veneering thickness in both crown systems to withstand clinical applications; however, the fracture patterns still underline the requirement of a core design that support a consistent thickness of the veneering ceramic, and it is recommended to conduct long-term prospective clinical studies to confirm findings reported in the present study.

scholarly journals Impacts of contracted endodontic cavities compared to traditional endodontic cavities in premolars

2020 ◽  
Author(s):  
Xia Juan ◽  
Wang weidong ◽  
Li Zhengmao ◽  
Lin Bingpeng ◽  
Zhang Qian ◽  
...  
Keyword(s):  
Root Canal ◽  
Fracture Resistance ◽  
Testing Machine ◽  
Filling Material ◽  
Root Canal Filling ◽  
Surface Areas ◽  
Significant Difference ◽  
3D Printed ◽  
Post Hoc

Abstract Background: This study aims to compare the percentage of dentin removed, instrumentation efficacy, root canal filling and load at fracture between contracted endodontic cavities, and traditional endodontic cavities on root canal therapy in premolars. Methods: Forty extracted intact human first premolars were imaged with micro-CT and randomly assigned to the contracted endodontic cavity (CEC) or traditional endodontic cavity (TEC) groups. CEC was prepared with the aid of a 3D-printed template, canals were prepared with a 0.04 taper M-Two rotary instrument, and cavities were restored with resin. Specimens were loaded to fracture in an Instron Universal Testing Machine after a fatigue phase. The data were analyzed by the independent samples T test and Mann-Whitney U test, appropriate post hoc tests. Results: In the premolars tested in vitro, the percentage of dentin removed in the premolars with two dental roots in the CEC group (3.85% ± 0.42%) was significantly smaller (P < 0.05) than in the TEC group (4.94% ± 0.5%). The untouched canal wall (UCW) after instrumentation for TECs (16.43% ± 6.56%) was significantly lower (P< .05) than the UCW (24.42% ± 9.19%) for CECs in single-rooted premolars. No significant differences were observed in the increased canal volume and surface areas in premolars between the TEC and CEC groups (P > 0.05). CECs conserved coronal dentin in premolars with two dental roots but no impact on the instrument efficacy. There were no differences between the CEC groups and the TEC groups in the percentage of filling material and voids (P > 0.05). In addition, the mean load at failure of premolars did not significantly differ between the CEC and TEC groups and there was no significant difference in the type of fracture (P > 0.05). Conclusion: The results of this study suggest that CEC could not improve the fracture resistance of the endodontically treated premolars. The instrumentation efficacy and the percentage of filling material did not significantly differ between CECs and TECs in premolars. Keywords: 3D-printed template, contracted endodontic cavities, instrumentation efficacy, root canal filling, fracture resistance

scholarly journals Fracture Resistance of a Bulk-Fill and a Conventional Composite and a Combination of Both for Coronal Restoration of Severely Damaged Primary Anterior Teeth

2019 ◽  
Author(s):  
Shahram Mosharrafian ◽  
Maryam Shafizadeh ◽  
Zeinab Sharifi
Keyword(s):  
Fracture Resistance ◽  
Treatment Time ◽  
Testing Machine ◽  
Anterior Teeth ◽  
Significant Difference ◽  
Group 3 ◽  
The Mean ◽  
Group 2 ◽  
One Way Anova

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.

scholarly journals ROOT END FILLING MATERIAL WHICH IS BETTER IN MARGINAL ADAPTATION? AN INVITRO STUDY.

2021 ◽  
Vol 5 (1) ◽  
Author(s):  
Devi Priya B ◽  
Afroz Kalmee ◽  
Omkar Eswara Babu Danda ◽  
Dasarthi A
Keyword(s):  
Mineral Trioxide Aggregate ◽  
Root Apex ◽  
Tricalcium Silicate ◽  
Marginal Adaptation ◽  
Filling Material ◽  
The Third ◽  
The Past ◽  
Filling Materials ◽  
Significant Difference ◽  
One Way Anova

Introduction: The sealing ability of the root end filling materials to the wall can be assessed by the marginal adaptations. Various materials have been used in the past. This study was conducted to assess the root-end filling materials ProRoot MTA, Biodentine, RetroMTA’s marginal adaptation. Materials and Methods: Ninety single-rooted teeth were divided to three equal groups of ProRoot MTA, RetroMTA and Biodentine. After the BMP and obturation, the third (3mm) of the root apex were cut, and cavities made with the ultrasonic technique. The transverse and the longitudinal sections were studied using the epoxy a replica under the SEM. One-way ANOVA was employed to associate the marginal gaps between the groups and P<0.05 was considered significant. Results: Significant difference in the longitudinal gaps was observed when the three groups were compared. Conversely, in the transverse sections no significant differences were seen in the groups. Conclusion: Biodentine yielded the best marginal adaptability when compared to the other two only in the longitudinal sections. Greater gaps were seen in the transverse sections in all the three groups. Keywords: Mineral trioxide aggregate, Tricalcium silicate, ProRoot MTA, Marginal adaptation

scholarly journals Comparison of the amount of apically extruded debris produced by four retreatment techniques: an ex vivo study

2017 ◽  
Vol 74 (4) ◽  
pp. 309
Author(s):  
Cristiane Ferreira Alfenas ◽  
Inês de Fátima De Azevedo Jacinto Inojosa ◽  
Júlio César De Azevedo Carvalhal ◽  
Mariana Teixeira Maneschy Faria ◽  
Fernanda Freitas Lins ◽  
...  
Keyword(s):  
Root Canal ◽  
Ex Vivo ◽  
Nickel Titanium ◽  
Filling Material ◽  
Root Canal Filling ◽  
Apical Extrusion ◽  
Significant Difference ◽  
The Mean ◽  
Ex Vivo Study ◽  
One Way Anova

Objective: the aim of this study was to compare the amount of apically extruded debris during the removal of root canal filling material using nickel-titanium rotary retreatment instruments and Hedström files. Material and Methods: sixty mandibular incisors with a single canal were instrumented and obturated by cold lateral compaction. For retreatment, specimens were randomly divided into four groups (n = 15): Hedström files with or without solvent; D-RaCe system and Mtwo retreatment system. Debris extruded apically during the removal of canal filling material was collected into preweighed Eppendorf tubes. The tubes were then stored in an incubator at 70°C for 5 days. The weight of the dry extruded debris was established by subtracting the preretreatment and postretreatment weight of the Eppendorf tubes for each group. The mean weights of extruded material were analyzed by one-way ANOVA. Results: the results showed that all retreatment techniques caused apical extrusion of debris, but no statistically significant difference was observed between groups (p>0.05). Conclusion: under the conditions of this study, all retreatment techniques caused apical debris extrusion.

scholarly journals Influence of hydrofluoric acid etching time and concentration on shear bond strength of metal brackets to ceramic surfaces

2019 ◽  
Vol 48 ◽  
Author(s):  
Cedirlei Gomes da Silveira ANDRADE ◽  
Diego Patrik Alves CARNEIRO ◽  
Mariana NABARRETTE ◽  
Américo Bortolazzo CORRER ◽  
Heloisa Cristina VALDRIGHI
Keyword(s):  
Bond Strength ◽  
Hydrofluoric Acid ◽  
Shear Bond Strength ◽  
Resin Composite ◽  
Acid Etching ◽  
Etching Time ◽  
Time Interval ◽  
Test Machine ◽  
Ceramic Surface ◽  
Significant Difference

Abstract Introduction Surface treatment prior to bonding ceramic brackets with hydrofluoric acid is indicated because of its ability to promote morphological changes necessary for adhesion. Objective To evaluate the shear bond strength (RUC) of metal brackets bonded to the feldspar ceramic surface under the action of hydrofluoric acid (AF), in different concentrations (5% and 10%) and different application times (30 and 60 seconds). Material and method Four nickel-chrome metal blocks that received an application of feldspathic ceramic were used, to which 80 metal brackets (Abzil/3M) were bonded and divided into 4 Groups (n=20) according to the acid etching procedure. The blocks were etched with 5% hydrofluoric acid for 30 and 60 seconds (AF5/30 and AF5/60, respectively) and 10% hydrofluoric acid for 30 and 60 seconds (AF10/30, AF10/60, respectively). The resin composite used was Transbond XT (3M) and the presence of a glazer was maintained on the ceramic surface. The specimens were placed on a Universal test machine Instron 4411 (Instron Corp, USA) to which a chisel was adapted to perform the shear test at a speed of 1mm/min. The data were submitted to the analysis of variance (ANOVA) and the Adhesive Remnant Index was evaluated. Result In the time interval of 30 seconds, there was no significant difference for the 5% and 10% hydrofluoric acid concentrations. In the 60-second time interval, the 10% concentration showed significantly higher shear bond strength values (p<0.05). The ARI showed predominance of scores 1 and 2. Conclusion It was concluded that 10% hydrofluoric acid showed higher shear bond strength values in 60 seconds of etching, while 5% hydrofluoric acid showed no significant difference between the etching times.

scholarly journals Fracture Resistance of Ceramic Laminate Veneers Bonded to Teeth with Class V Composite Fillings after Cyclic Loading

2018 ◽  
Vol 2018 ◽  
pp. 1-6
Author(s):  
Leyla Sadighpour ◽  
Farideh Geramipanah ◽  
Vanya Rasaei ◽  
Mohammad J. Kharazi Fard
Keyword(s):  
Cyclic Loading ◽  
Fracture Resistance ◽  
Resin Cement ◽  
Crown Height ◽  
Class V ◽  
Significant Difference ◽  
Failure Loads ◽  
The Mean ◽  
Laminate Veneers ◽  
One Way Anova

Purpose. Porcelain laminate veneers (PLVs) are sometimes required to be used for teeth with composite fillings. This study examined the fracture strength of PLVs bonded to the teeth restored with different sizes of class V composite fillings. Materials and Methods. Thirty-six maxillary central incisors were divided into three groups (n=12): intact teeth (control) and teeth with class V composite fillings of one-third or two-thirds of the crown height (small or large group, resp.). PLVs were made by using IPS e.max and bonded with a resin cement (RelyX Unicem). Fracture resistance (N) was measured after cyclic loading (1 × 106 cycles, 1.2 Hz). For statistical analyses, one-way ANOVA and Tukey test were used (α=0.05). Results. There was a significant difference between the mean failure loads of the test groups (P=0.004), with the Tukey-HSD test showing lower failure loads in the large-composite group compared to the control (P=0.02) or small group (P=0.05). The control and small-composite groups achieved comparable results (P>0.05). Conclusions. Failure loads of PLVs bonded to intact teeth and to teeth with small class V composite fillings were not significantly different. However, extensive composite fillings could compromise the bonding of PLVs.

Fracture Resistance of Teeth Obturated with RealSeal™ Using Two Different Chelating Agents: An in vitro Study

2010 ◽  
Vol 11 (1) ◽  
pp. 25-32 ◽  
Author(s):  
Ahmed M. Al-Kahtani ◽  
Hussam Al-Fawaz ◽  
Mohammed Al-Sarhan ◽  
Khalil Al-Ali
Keyword(s):  
Fracture Resistance ◽  
Chelating Agents ◽  
Control Group ◽  
Filling Material ◽  
High Fracture ◽  
Human Teeth ◽  
Significant Difference ◽  
Group 2 ◽  
Group 1

Abstract Objectives The aim of this study was to evaluate the fracture resistance of endodontically treated teeth filled with a resin-based obturation material using two different chelating agents. Methods and Materials Forty extracted singlecanal human teeth were prepared, instrumented, and randomly divided into three groups: Group 1 (n=15) received a final flush with 10 ml of neutralized 17% EDTA, followed by 10 ml of sodium hypochlorite (NaOCl), then obturated using lateral condensation with RealSeal. Group 2 (n=15) received a final flush of BioPure™ MTAD™, followed by 10 ml of NaOCl, then obturated using lateral condensation with RealSeal. Group 3, the control group (n=10), was instrumented but not obturated, then the root canal opening was sealed with a temporary filling material. The specimens were stored in 100% humidity for 10 days, mounted in polyester resin, and loaded to failure. Results The ANOVA revealed a significant difference between the control group and the experimental groups, although there was no statistically significant difference between Group 1 and Group 2 (p=0.05). The MTAD group displayed higher mean fracture load values than the EDTA group. Conclusions It can be concluded that filling the root canals with RealSeal™ increased the in vitro resistance to fracture of single-canal extracted human teeth when compared to instrumented and unobturated teeth. Teeth treated with MTAD demonstrated high fracture-resistance values when compared to teeth treated with 17% EDTA, but they were not statistically significant. Citation Al-Kahtani AM, Al-Fawaz H, Al-Sarhan

Effect of Postoperative Bleaching on Marginal Leakage of Resin Composite and Resin-Modified Glass Ionomer Restorations at Different Delayed Periods of Exposure to Carbamide Peroxide

2009 ◽  
Vol 10 (6) ◽  
pp. 9-16 ◽  
Author(s):  
Horieh Moosavi ◽  
Marjaneh Ghavamnasiri ◽  
Vahideh Manari
Keyword(s):  
Resin Composite ◽  
Wilcoxon Test ◽  
Filling Material ◽  
Glass Ionomer ◽  
Carbamide Peroxide ◽  
Control Groups ◽  
Human Teeth ◽  
Composite Restorations ◽  
Significant Difference ◽  
Resin Modified Glass Ionomer

Abstract Aim To evaluate the effect of dental bleaching with carbamide peroxide at different exposure times on the microleakage of resin composite and resin-modified glass ionomer restorations after placement in extracted human teeth. Methods and Materials 120 Class V cavity preparations were placed at the cementoenamel junction (CEJ) of human teeth. Half of the cavities were restored with Filtek P60 resin composite(C) and the other half were restored with Fuji II LC resin-modified glass ionomer (G). Each group was randomly divided into four subgroups (n=15). Groups C1 and G1 were not bleached and stored in artificial saliva at 37°C to serve as control groups, while in Groups C2 and G2, C3 and G3, and C4 and G4 specimens were exposed to a 15% carbamide peroxide gel for one day, one week, and two weeks, respectively, following the placement of restorations. Microleakage was assessed using the dye penetration method. Data were analyzed using the Kruskal-Wallis and Wilcoxon tests (p=0.05). Results The Kruskal-Wallis test showed no significant difference among all groups of composite or glass ionomer restorations with either enamel or dentinal margins with regard to microleakage (p>0.05). The Wilcoxon test revealed more marginal leakage in the enamel/ glass ionomer margins than the enamel/ composite margins (p<0.05). In comparisons within each group, the Wilcoxon test showed there was more microleakage in dentinal margins of composite restorations than in the enamel margins in the test groups (p<0.05). The dentinal margins of the glass ionomer in control groups showed more leakage than the enamel margins, but after the bleaching procedure all experimental groups showed statistically similar microleakage in both the enamel and dentinal margins (p>0.05). Conclusions Postoperative bleaching with carbamide peroxide could increase microleakage in the dentinal margins of composite and the enamel margins of resin-modified glass ionomer restorations. Clinical Significance Rebonding of resin composite restorations should be considered following bleaching with 15% carbamide peroxide in order to reseal the margins. Resin-modified glass ionomer is not suitable as a filling material before bleaching because of its susceptibility to increased microleakage. Citation Moosavi H, Ghavamnasiri M, Manari V. Effect of Postoperative Bleaching on Marginal Leakage of Resin Composite and Resin-Modified Glass Ionomer Restorations at Different Delayed Periods of Exposure to Carbamide Peroxide. J Contemp Dent Pract [Internet]. 2009 Nov; 10(6):009-016. Available from: http://www.thejcdp. com/journal/view/volume10-issue6-moosavi.

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