scholarly journals Vickers Hardness and Shrinkage Stress Evaluation of Low and High Viscosity Bulk-Fill Resin Composite

Polymers ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1477
Author(s):  
Allegra Comba ◽  
Nicola Scotti ◽  
Tatjana Maravić ◽  
Annalisa Mazzoni ◽  
Massimo Carossa ◽  
...  
Keyword(s):  
Resin Composite ◽  
Linear Regression Analysis ◽  
In Vitro Study ◽  
High Viscosity ◽  
Shrinkage Stress ◽  
Light Curing ◽  
Different Depths ◽  
Bonferroni Test ◽  
Post Hoc

The aim of this in vitro study was to evaluate the hardness and shrinkage stress (SS) of six bulk-fill resin composites. To evaluate microhardness (MH), ten 6 mm specimens were prepared using a metal mold for each selected bulk-fill resin composite and irradiated from the top side for 40 s using an LED light. After 24 h of storage, Vickers MH was evaluated on the upper, lower and lateral sides of the specimens. SS evaluation was then performed with a universal machine, which evaluated the contraction force generated by a bulk-fill composite specimen placed between two metal cylinders during and after light curing. The results were evaluated with a one-way ANOVA test with a post-hoc Bonferroni test and linear regression analysis (p < 0.05). All materials showed a significant MH decrease between the top and bottom surfaces. However, the bulk-fill materials tested performed differently when considering lateral depth progression. ANOVA tests for SS evaluation showed that both SDR and Venus Bulk Fill had significantly lower stress during irradiation than other tested materials. Further, MH decrease became significantly lower from the top surface at different depths in each tested group. Among the different resins, Venus Bulk Fill and SDR showed not only inferior hardness, but also a significant reduction in SS.

scholarly journals Depth-Related Curing Potential of Ormocer- and Dimethacrylate-Based Bulk-Fill Composites

Materials ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 6753
Author(s):  
Ramona S. Oltramare ◽  
Reto Odermatt ◽  
Phoebe Burrer ◽  
Thomas Attin ◽  
Tobias T. Tauböck
Keyword(s):  
Double Bond ◽  
Repeated Measures ◽  
In Vitro Study ◽  
High Viscosity ◽  
Degree Of Conversion ◽  
Double Bond Conversion ◽  
Nanohybrid Composite ◽  
Post Hoc ◽  
One Way Anova

The aim of this in vitro study was to investigate the degree of C=C double bond conversion of high-viscosity dimethacrylate- or ormocer-based bulk-fill composites as a function of measurement depth. Four bulk-fill composites (Tetric EvoCeram Bulk Fill, x-tra fil, SonicFill, and Bulk Ormocer) and the conventional nanohybrid composite Tetric EvoCeram were applied in standardized Class II cavities (n = 6 per group) and photoactivated for 20 s at 1350 mW/cm2. The degree of conversion of the composites was assessed using Fourier-transform infrared spectroscopy at seven measurement depths (0.15, 1, 2, 3, 4, 5, 6 mm). Data were analyzed using repeated measures ANOVA and one-way ANOVA with Bonferroni post-hoc tests (α = 0.05). The investigated bulk-fill composites showed at least 80% of their maximum degree of conversion (80% DCmax) up to a measuring depth of at least 4 mm. Tetric EvoCeram Bulk Fill and Bulk Ormocer achieved more than 80% DCmax up to a measuring depth of 5 mm, x-tra fil up to 6 mm. The conventional nanohybrid composite Tetric EvoCeram achieved more than 80% DCmax up to 3 mm. In contrast to the conventional composite, the investigated ormocer- and dimethacrylate-based bulk-fill composites can be photo-polymerized in thick layers of up to at least 4 mm with regard to their degree of C=C double bond conversion.

Comparative evaluation of shear bond strength of composite to dentin in presence of different dental liners: An in-vitro study

2021 ◽  
Author(s):  
Ladan Ranjbar Omrani ◽  
Saba Tohidkhah ◽  
Elham Ahmadi ◽  
Mahdi Abbasi ◽  
Reza Morvaridi Farimani
Keyword(s):  
Bond Strength ◽  
Shear Bond Strength ◽  
Resin Composite ◽  
Testing Machine ◽  
Glass Ionomer Cement ◽  
In Vitro Study ◽  
Control Group ◽  
The One ◽  
Post Hoc

Abstract Background: The aim of the current study was to evaluate and compare the influence of Dycal, Lime-lite, Theracal LC, Biodentine, Resin-modified glass ionomer cement (RMGIC), and Activa Bioactive as the pulp capping material on the shear bond strength of resin composite to dentin.Methods: A total of 70 extracted caries-free molars were randomly assigned to seven groups. Six test groups were covered with various protective liners: Dycal (GD), Theracal LC (GT), lime-lite (GL), Activa Bioactive (GA), Biodentine (GB), RMGIC (GR). The control group (GC)received no liner pretreatment. Each sample was bonded to resin composite using the total-etch tetric N bond adhesive. The samples were then tested for shear bond strength using the universal testing machine at a cross-head speed of 1 mm/min until bond failure occurred. The data were analyzed using the one-way ANOVA test followed by the Tamhane post-hoc test for pairwise comparisons of the groupsResults: Independent of the type of the applied liner, all groups exhibited inferior SBS to dentine compared to the control group. GT and GR showed significantly higher shear bond strength than GB and GD, which showed the lowest shear bond strength. GL and GA also had significantly lower SBS results than GT. The mode of fracture was predominantly cohesive in GD, GB, and GT and adhesive in GA.Conclusion: This present study concludes that the bond strength of resin-composite to dentine can be affected differently using various types of liners.

scholarly journals Bulk-Fill Direct Restorative Materials: An In Vitro Assessment of Their Physio-Mechanical Properties

Oral ◽  
2021 ◽  
Vol 1 (2) ◽  
pp. 75-87
Author(s):  
Hui Woon Yeo ◽  
May Yeh Loo ◽  
Mariam Alkhabaz ◽  
Kai Chun Li ◽  
Joanne Jung Eun Choi ◽  
...  
Keyword(s):  
Flexural Strength ◽  
Wear Testing ◽  
Restorative Materials ◽  
Different Depths ◽  
Bonferroni Test ◽  
In Vitro Assessment ◽  
High Level ◽  
Post Hoc ◽  
One Way Anova

Bulk-fill restorative material has gained popularity in clinical practice, due to their perceived timesaving aspect. Objective was to compare the properties of bulk-fill direct restorative materials. Filtek Z350 (CR), Filtek One Bulk Fill Restorative (BF), Fuji IX and EQUIA Forte (EF) were compared. Thirty specimens from each material were prepared according to ISO 4049 for three-point flexural strength. Elastic moduli and hardness (n = 20) were evaluated using nanoindentation. Depth of cure (DC) (n = 20) was measured for BF at three different depths (2, 3, 4 mm) and at two irradiation times (20 and 40 s). Wear testing was carried out for three different periods (3, 6, 12 month(s)). All specimens were stored in 37 °C water for 24 h prior to testing. Results were evaluated using one-way ANOVA followed by a post hoc Bonferroni test (p < 0.05). BF and CR showed a significantly higher flexural strength than other groups (p < 0.05), and the highest Weibull modulus was found in CR. BF showed sufficient DC with at least 85%, at all thicknesses. CR and BF also had a high level of translucency than EF and Fuji IX. Significant differences in flexural strength were found among all materials except between Fuji IX and EF. While all material tested are suitable for use clinically, BF and CR have superior properties than GIC based bulk-fill.

scholarly journals Influence of composite resin volume and C-factor on the polymerization shrinkage stress

2016 ◽  
Vol 19 (2) ◽  
pp. 72 ◽  
Author(s):  
Rafael Francisco Lia Mondelli ◽  
Marilia Mattar de Amoêdo Campos Velo ◽  
Rafael Simões Gonçalves ◽  
Bhenya Ottoni Tostes ◽  
Sergio Kiyoshi Ishikiriama ◽  
...  
Keyword(s):  
Composite Resin ◽  
In Vitro Study ◽  
Composite Resins ◽  
Steel Plates ◽  
Shrinkage Stress ◽  
Lower Stress ◽  
Polymerization Shrinkage ◽  
Light Curing ◽  
Clinical Problems

<p>Objective: Composite polymerization shrinkage<br />stress is an inherent process of chemical and light<br />composite resin activation. Consequently, this fact has<br />been associated to potential clinical problems. The<br />aim of the present in vitro study was to evaluate the<br />volume and C-factor influence on chemical and lightcuring<br />composite resin polymerization shrinkage<br />stress, using a non-rigid method that thereby provides<br />lower stress values, causing a minimal deflection in<br />load cell. Materials and Methods: The contraction<br />forces of the Z-250 and Concise composite resins<br />during polymerization were recorded in an UTM in<br />two experiments. In the first experiment, the Z-250<br />composite was inserted beetwen two rectangular<br />steel plates (6.0 x 2.0 mm), varyng the resin volumes<br />and C-factors, in a single increment, polymerized for<br />20 s and the forces generated were recorded for 120<br />s. In the second experiment, a pair of rectangular steel<br />plates (3x2mm) and two square steel plates (2x2mm),<br />with varied heights (2; 3 mm, respectively), were<br />used to determine the C-factor (0.6; 0.3) influence.<br />Results: The polymerized Z-250 results showed that<br />the volume variations, independent of the C-factor,<br />had a direct influence on the shrinkage stress,<br />different from the Concise, which was influenced by<br />the C-factor. Conclusion: The present study showed<br />that a higher volume of composite resins determines<br />an increase in the shrinkage stress of light-curing<br />composites.</p><p><strong>Keywords</strong></p><p>C-factor. Composite resin. Polymerization. Shrinkage<br />stress.</p>

scholarly journals Riboflavin and Its Effect on Dentin Bond Strength: Considerations for Clinical Applicability—An In Vitro Study

2022 ◽  
Vol 9 (1) ◽  
pp. 34
Author(s):  
Franziska Beck ◽  
Nicoleta Ilie
Keyword(s):  
Bond Strength ◽  
Resin Composite ◽  
In Vitro Study ◽  
Dental Resin ◽  
Hybrid Layer ◽  
Clinical Applicability ◽  
Human Dentin ◽  
Post Hoc ◽  
Self Etch

Bioactive collagen crosslinkers propose to render the dentin hybrid layer less perceptive to hydrolytic challenge. This study aims to evaluate whether bond strength of dental resin composite to dentin benefits from riboflavin (RB)-sensitized crosslinking when used in a clinically applicable protocol. A total of 300 human dentin specimens were prepared consistent with the requirements for a macro-shear bond test. RB was applied on dentin, either incorporated in the primer (RBp) of a two-step self-etch adhesive or as an aqueous solution (RBs) before applying the adhesive, and blue light from a commercial polymerization device was used for RB photoactivation. Bonding protocol executed according to the manufacturer’s information served as control. Groups (n = 20) were tested after 1 week, 1 month, 3 months, 6 months or 1 year immersion times (37 °C, distilled water). The different application methods of RB significantly influenced bond strength (p < 0.001) with a medium impact (η2p = 0.119). After 1 year immersion, post hoc analysis identified a significant advantage for RB groups compared to RBp (p = 0.018), which is attributed to a pH-/solvent-dependent efficiency of RB-sensitized crosslinking, stressing the importance of formulation adjustments. We developed an application protocol for RB-sensitized crosslinking with emphasis on clinical applicability to test its performance against a gold-standard adhesive, and are confident that, with a few adjustments to the application solution, RB-sensitized crosslinking can improve the longevity of adhesive restorations in clinics.

scholarly journals The Evaluation of apically extruded debris during root canal preparation using Pro-Taper Universal, ProTaper Gold and Reciproc Blue system: An in-vitro comparative Study

2020 ◽  
Vol 6 (2) ◽  
pp. 11-15
Author(s):  
Padma Chandra ◽  
Rajesh Prasad ◽  
Surendra Kumar Mishra ◽  
Jagdish Chandra
Keyword(s):  
File System ◽  
In Vitro Study ◽  
Nickel Titanium ◽  
Root Canal Preparation ◽  
Human Teeth ◽  
Significance Level ◽  
Significant Difference ◽  
Bonferroni Test ◽  
Post Hoc

ABSTRACT Aims & Objectives: The purpose of this study was to compare the amount of apically extruded debris with four nickel-titanium instruments i.e ProTaper Universal, ProTaper Gold, and Reciproc Blue system, Hand K file System. Methods: Eighty extracted single-rooted mandibular premolar human teeth were randomly assigned to 4 groups (n = 20). The canals were instrumented using 1 of the following instruments: ProTaper Universal, ProTaper Gold, and Reciproc Blue system, Hand K file System. Apically extruded debris during instrumentation was collected into preweighed Eppendorf tubes. The weight of the extruded debris was calculated by subtracting the weight of the empty tubes from that of the tubes containing the debris. The data were analyzed statistically using the analysis of variance (ANOVA) and Post-hoc bonferroni test at a significance level of P < .05. Results: All the instrumentation systems resulted in production of extruded debris. The amount of extruded debris was significantly more in Hand K file than PTU, PTG and Reciproc Blue (P<0.05). The PTU system was associated with significantly more extruded debris than the PTG(P=0.041), Reciproc Blue systems (P=`0.011), whereas no significant difference was found in the amount of the debris extruded between PTG and Reciproc Blue (P=0.271). The amount of extruded debris was least in Reciproc Blue in comparison to all used system. Conclusions: Within the limitations of this in vitro study, the amount of apically extruded debris registered for the different files tested was highest for hand file, Protaper Universal, followed by the ProTaper Gold and least in Reciproc Blue.

Comparative Evaluation of Shear Bond Strength of Composite to Dentin in Presence of Calcium Releasing Liners: An In-Vitro Study

2021 ◽  
Author(s):  
Saba Tohidkhah ◽  
Elham Ahmadi ◽  
Mahdi Abbasi ◽  
Reza Morvaridi Farimani ◽  
Ladan Ranjbar Omrani
Keyword(s):  
Bond Strength ◽  
Shear Bond Strength ◽  
Resin Composite ◽  
Testing Machine ◽  
Glass Ionomer Cement ◽  
In Vitro Study ◽  
Control Group ◽  
The One ◽  
Post Hoc

Abstract Background: The aim of current study was to evaluate and compare the influence of Dycal, Lime-lite, Theracal LC, Biodentine, Resin-modified glass ionomer cement (RMGIC), and Activa Bioactive as the pulp capping material on the shear bond strength of resin composite to dentin.Methods: A total of 70 extracted caries-free molars were randomly assigned to seven groups. Six test groups were covered with various protective liners: Dycal (GD), Theracal LC (GT), lime-lite (GL), Activa Bioactive (GA), Biodentine (GB), RMGIC (GR). The control group (GC)received no liner pretreatment. Each sample was bonded to resin composite using the total-etch tetric N bond adhesive. The samples were then tested for shear bond strength using the universal testing machine at a cross-head speed of 1 mm/min until bond failure occurred. The data were analyzed using the one-way ANOVA test followed by the Tamhane post-hoc test for pairwise comparisons of the groupsResults: Independent of the type of the applied liner, all groups exhibited inferior SBS to dentine compared to the control group. GT and GR showed significantly higher shear bond strength than GB and GD, which showed the lowest shear bond strength. GL and GA also had significantly lower SBS results than GT. The mode of fracture was predominantly cohesive in GD, GB, and GT and adhesive in GA.Conclusion: This present study concludes that the bond strength of resin-composite to dentine can be affected differently using various types of liners.

scholarly journals The effect of one-step and multi-step polishing systems on the surface roughness and microhardness of novel resin composites

2012 ◽  
Vol 06 (02) ◽  
pp. 198-205 ◽  
Author(s):  
Ugur Erdemir ◽  
Hande Sar Sancakli ◽  
Esra Yildiz
Keyword(s):  
Surface Roughness ◽  
Resin Composite ◽  
In Vitro Study ◽  
Resin Composites ◽  
Significance Level ◽  
Significant Difference ◽  
One Step ◽  
Wet Ground ◽  
Post Hoc

ABSTRACTObjectives: The objective of this in vitro study was to evaluate the surface roughness and microhardness of three novel resin composites containing nanoparticles after polishing with one-step and conventional multi-step polishing systems.Methods: A total of 126 specimens (10 X 2 mm) were prepared in a metal mold using three nanocomposites (Filtek Supreme XT, Ceram-X, and Grandio), 21 specimens of each resin composite for both tests (n=63 for each test). Following light curing, seven specimens from each group received no polishing treatment and served as controls for both tests. The specimens were randomly polished using PoGo and Sof-Lex systems for 30 seconds after being wet-ground with 1200-grit silicon carbide paper. The mean surface roughness of each polished specimen was determined with a profilometer. The microhardness was determined using a Vickers hardness measuring instrument with a 200-g load and 15 seconds dwell time. The data were analyzed using the Kruskal-Wallis test and the post hoc Dunn's multiple comparison tests at a significance level of .05.Results: Among all materials, the smoothest surfaces were obtained under a matrix strip (control) (P<.05). There were no statistically significant differences among polishing systems in the resin composites for surface roughness (P>.05). The lowest hardness values for the three resin composites were obtained with a matrix strip, and there was a statistically significant difference compared with other polishing systems (P<.05) whereas no statistically significant differences were observed between the polishing systems (P<.05).Conclusion: The current one-step polishing system appears to be as effective as multi-step systems and may be preferable for polishing resin composite restorations. (Eur J Dent 2012;6:198-205)

Minimal Gap Size and Dentin Wall Lesion Development Next to Resin Composite in a Microcosm Biofilm Model

2017 ◽  
Vol 51 (5) ◽  
pp. 475-481 ◽  
Author(s):  
Tamires T. Maske ◽  
Nicolien K. Kuper ◽  
Maximiliano S. Cenci ◽  
Marie-Charlotte D.N.J.M. Huysmans
Keyword(s):  
Resin Composite ◽  
Linear Regression Analysis ◽  
In Vitro Study ◽  
Gap Size ◽  
Lesion Development ◽  
Secondary Caries ◽  
Biofilm Model ◽  
Wall Lesion ◽  
Wall Lesions

This in vitro study investigated the development of dentin wall lesions next to resin composite containing very small gap sizes using an in vitro biofilm model, and evaluated whether a relevant threshold for the gap size could be established. Microcosm biofilms were grown for 14 days within small interfacial gaps between dentin-resin composite discs under intermittent cariogenic challenge. The factor under study was gap size: samples were either restored with composite resin without adhesive procedure (no intentional gap; no bonding [NB] group) or with intentional gaps of 30, 60, or 90 µm, or with complete adhesive procedure (no gap; bonding [B] group). Secondary caries wall lesion progression was measured in lesion depth (LD) and mineral loss (ML) using transversal wavelength independent microradiography at 3 locations: outer surface lesion and wall lesions at 200 and 500 µm distance from gap entrance. Results from linear regression analysis showed that the presence of an intentional gap (30, 60, and 90 µm) affected the secondary caries progression at 200 µm from the gap entrance (p ≤ 0.013). The NB group did not show significant wall lesion development (ML and LD, p ≥ 0.529). At 500 µm distance almost no wall caries development was observed. In conclusion, dentin wall lesions developed in minimal gap sizes, and the threshold for secondary wall lesion development was a gap of around 30 µm in this microcosm biofilm model.

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