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.

scholarly journals The influence of different screw tightening forces on the vertical misfit of implant-supported frameworks

2005 ◽  
Vol 13 (2) ◽  
pp. 120-125 ◽  
Author(s):  
Diego Klee de Vasconcellos ◽  
Marco Antonio Bottino ◽  
Renato Sussumu Nishioka ◽  
Luiz Felipe Valandro ◽  
Elza Maria Valadares da Costa
Keyword(s):  
Repeated Measures ◽  
In Vitro Study ◽  
Pairwise Comparisons ◽  
Tukey Test ◽  
Nickel Chromium ◽  
Marginal Discrepancy ◽  
The Mean ◽  
Post Hoc ◽  
One Way Anova

OBJECTIVES: The present in vitro study was designed to compare the differences in the vertical misfit of implant-supported frameworks using three different forces for tightening the bridge locking screws: fastening by hand until first resistance, and using torque drivers with 10 and 20Ncm. METHODS: The investigation was conducted based on the results given by 9 six-unit nickel-chromium (2 abutments/ 4 pontics) screw-retained implant-supported frameworks. The structures were exposed to simulated porcelain firings. The marginal misfit measurements were made using a traveling measuring microscope at selected screw tightening forces: fastening by hand until first resistance, and using torque drivers with 10 and 20Ncm. The results were submitted to one-way ANOVA with repeated measures on one factor, and post hoc pairwise comparisons using Tukey test (5%). RESULTS: The mean marginal misfit of the frameworks, fastening the screws by hand until first resistance, was 41.56µm (SD±12.45µm). The use of torque driver devices caused a significant reduction in marginal opening (p<0.05). With the lowest torque available (10Ncm), the mean marginal discrepancy at the abutment-framework interface was reduced an average of 52% to a mean marginal opening of 19.71µm (SD±2.97µm). After the use of the 20Ncm torque driver, the mean marginal discrepancy of the frameworks was reduced an average of 69% to a mean marginal opening of 12.82µm (SD±4.0µm). Comparing the use of torque drivers with 10 and 20 Ncm torque, the means are not significantly different from one another. CONCLUSION: The seating force has an important effect on the vertical misfit measurements, once it may considerably narrow the vertical misfit gaps at the abutment-framework interface, thus leading to a misjudgment of the real marginal situation.

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 AN IN VITRO STUDY TO EVALUATE THE TEAR STRENGTH OF AUTOCLAVABLE PVS, SMART WETTING PVS AND CONDENSATION SILICONE AND COMPARE THEM UPON AUTOCLAVING AND DISINFECTION.

2020 ◽  
pp. 67-70
Author(s):  
Garima Gothwal ◽  
Hemant Kumar Sharma ◽  
Kusum Singh ◽  
Richa Sengar
Keyword(s):  
Statistical Analysis ◽  
Testing Machine ◽  
In Vitro Study ◽  
Tear Strength ◽  
Universal Testing ◽  
Impression Materials ◽  
Different Types ◽  
Post Hoc ◽  
One Way Anova

Aim: The tear strength of three different types of elastomeric impression materials was measured after disinfection and sterilization. Material and Method: Dumb-bell shaped Tear strength specimens were prepared according to ISO 34-1 standardization. Ninety samples were prepared followed by disinfection and sterilization and tested with trouser piece method on Instron universal testing machine at a speed of 10 mm/min. One-way ANOVA, followed by Tukey post hoc test was used for statistical analysis. Results: No signicant difference was found when AFFINIS, SPEEDEX and AQUASIL were compared individually. When materials were compared with each other signicant difference was present, highest AQUASIL while SPEEDEX and AFFINIS almost alike. Conclusion: It was concluded that tear strength of AQUASIL was the highest. Disinfection and autoclaving had no signicant inuence on the three materials and showed adequate tear strength.

scholarly journals The effect of 5% NaOCl and 17% EDTA, at 24hrs and 8days, on the microhardness of MTA, Biodentine and Pozzolan cement: An in- vitro study.

2021 ◽  
Vol 6 (3) ◽  
pp. 16-21
Author(s):  
Sarita Dasani ◽  
Baljeet S Hora ◽  
Rucheeta S Ajmera ◽  
Brijesh Gupta ◽  
Yadnesh Dondulkar ◽  
...  
Keyword(s):  
Mineral Trioxide Aggregate ◽  
In Vitro Study ◽  
Vitro Study ◽  
Time Points ◽  
Post Hoc ◽  
Vicker’S Microhardness ◽  
One Way Anova

Aim & Objectives: The aim of this study was to evaluate the effects, at 24 h and 8 days, of 5% NaOCl and 17% EDTA on the Vicker’s microhardness of Mineral Trioxide Aggregate(MTA Angelus) (MTAA), Biodentine(Septodont, Saint Maur des Fosse’s France) and Pozzolan based endodontic cement named Endocem MTA(Maruchi, Wonju, Korea). Materials and method: Sixty samples of MTAA, Biodentine and Endocem MTA were tested for baseline microhardness at 24 h. They were divided into 12 subgroups (5% NaOCl or 17% EDTA, 24 h and 5% NaOCl or 17% EDTA at 8 days) and microhardness was evaluated at different time points. Results were recorded and analysed statistically via one-way ANOVA and Tukey’s post hoc  test. Results: MTAA had a higher baseline microhardness than both biodentine and Endocem MTA. At 24 hrs, the microhardness of all the materials was reduced by NaOCl and EDTA. At 8 days, NaOCl reduced the microhardness of MTA but that of Biodentine and Endocem MTA was increased. EDTA at 8 days, reduced the microhardness of both MTAA and Biodentine but an increase was seen with Endocem MTA. Conclusion: Changes in microhardness of MTAA, Biodentine and Pozzolan cement(Endocem MTA) were associated with the time for which the materials are allowed to set as well as the irrigating agent used,.  

scholarly journals The Effects of Different Antioxidant Agents on the Microtensile Bond Strength of Composite Resin to Bleached Enamel

2021 ◽  
pp. 258-269
Author(s):  
Nurcan Ozakar Ilday ◽  
Ozcan Karatas ◽  
Latife Altınok Uygun ◽  
Pınar Gul
Keyword(s):  
Bond Strength ◽  
Composite Resin ◽  
Artificial Saliva ◽  
In Vitro Study ◽  
Microtensile Bond Strength ◽  
Antioxidant Agents ◽  
Composite Resin Restoration ◽  
Post Hoc ◽  
One Way Anova

Objective: The objective of this in vitro study is to examine the effect of antioxidants on the bonding strength of composite resin to bleached enamel. Materials and Methods: One hundred twenty non decay teeth were used in this study. Specimens were cut from the enamel cement junction. Then the specimens were randomly assigned into two groups-office bleaching and home bleaching. Bleaching antioxidants were applied to the first 12 subgroups. The specimens in the remaining 12 groups were kept in artificial saliva for 14 days and antioxidants were applied. Composite resin restoration was applied to all specimens. A cutting device was employed to obtain six specimens (0.9mm) from each tooth, and the microtensile bond strength (μTBS) test was performed. Data were analyzed using one-way ANOVA, the paired t-test, and Duncan’s post hoc test (p=0.05). Results: In office bleaching specimens, immediate antioxidant application increased the μTBS values (p<0.05). Comparisons of the antioxidants individually revealed that bonding values increased after two weeks in specimens subjected to antioxidant application (p<0.05). In office bleaching specimens, immediate antioxidant application increased the μTBS values (p>0.05). Mean μTBS values in the groups to which antioxidants were applied two weeks after home bleaching were higher than those in the groups in which antioxidants were applied immediately. Conclusion: The use of antioxidants after bleaching may increase the MTBS value.  The clinician should take this into account especially in immediate restoration applications after bleaching.

scholarly journals Tooth discoloration induced by apical plugs with hydraulic calcium silicate-based cements in teeth with open apices—a 2-year in vitro study

2021 ◽  
Author(s):  
Ralf Krug ◽  
C. Ortmann ◽  
S. Reich ◽  
B. Hahn ◽  
G. Krastl ◽  
...  
Keyword(s):  
Calcium Silicate ◽  
In Vitro Study ◽  
Color Difference ◽  
Blood Contamination ◽  
Tooth Color ◽  
Color Changes ◽  
Gutta Percha ◽  
Tooth Discoloration ◽  
Post Hoc

Abstract Objectives To assess tooth discoloration induced by different hydraulic calcium silicate-based cements (HCSCs), including effects of blood and placement method. Materials and methods Eighty bovine teeth cut to a length of 18 mm (crown 8 mm, root 10 mm) were randomly assigned to 10 groups (n = 8), receiving orthograde apical plug treatment (APT). Apical plugs were 4 mm in length and made of ProRoot MTA (Dentsply), Medcem MTA (Medcem), TotalFill BC RRM Fast Set Putty (Brasseler), or Medcem Medical Portland Cement (Medcem) plus bismuth oxide (Bi2O3) with and without bovine blood. Further, orthograde (with or without preoperative adhesive coronal dentin sealing) and retrograde APT were compared. Teeth were obturated with gutta-percha and sealer, sealed with composite and stored in distilled water. Tooth color was measured on apical plug, gutta-percha/sealer, and crown surface before treatment versus 24 h, 1, 3, 6, 12, and 24 months after treatment by spectrophotometry. Color difference (ΔE) values were calculated and analyzed by Shapiro–Wilk test, ANOVA with post hoc tests, Friedman test, t test, and post hoc tests with Bonferroni correction (α = .05). Results Tooth discoloration occurred in all groups with no significant differences between HCSCs (p > .05). After 24 months, color changes were prominent on roots but insignificant on crowns. Blood contamination induced a significantly decreased luminescence (p < .05). Blood had a stronger impact on tooth color than Bi2O3. No relevant effects of retrograde placement (p > .05) or preoperative dentin sealing (p > .05) were detected. Conclusions Apical plugs of the tested HCSCs cause discoloration of bovine roots, but not discoloration of bovine tooth crowns within a 24-month period. Clinical relevance APT should be performed carefully while avoiding direct contact with the coronal dentin, and in that case no aesthetic impairments occur.

scholarly journals Potential of different fluoride gels to prevent erosive tooth wear caused by gastroesophageal reflux

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Philipp Körner ◽  
Luca Georgis ◽  
Daniel B. Wiedemeier ◽  
Thomas Attin ◽  
Florian J. Wegehaupt
Keyword(s):  
Gastroesophageal Reflux ◽  
Artificial Saliva ◽  
In Vitro Study ◽  
Tooth Wear ◽  
Control Group ◽  
Erosive Tooth Wear ◽  
Custom Made ◽  
Post Hoc ◽  
Bovine Enamel

Abstract Background This in-vitro-study aimed to evaluate the potential of different fluoride gels to prevent gastroesophageal reflux induced erosive tooth wear. Methods Surface baseline profiles of a total of 50 bovine enamel specimens [randomly assigned to five groups (G1–5)] were recorded. All specimens were positioned in a custom made artificial oral cavity and perfused with artificial saliva (0.5 ml/min). Reflux was simulated 11 times a day during 12 h by adding HCl (pH 3.0) for 30 s (flow rate 2 ml/min). During the remaining 12 h (overnight), specimens were stored in artificial saliva and brushed twice a day (morning and evening) with a toothbrush and toothpaste slurry (15 brushing strokes). While specimens in the control group (G1) did not receive any further treatment, specimens in G2–5 were coated with different fluoride gels [Elmex Gelée (G2); Paro Amin Fluor Gelée (G3); Paro Fluor Gelée Natriumfluorid (G4); Sensodyne ProSchmelz Fluorid Gelée (G5)] in the evening for 30 s. After 20 days, surface profiles were recorded again and enamel loss was determined by comparing them with the baseline profiles. The results were statistically analysed using one-way analysis of variance (ANOVA) followed by Tukey`s HSD post-hoc test. Results The overall highest mean wear of enamel (9.88 ± 1.73 µm) was observed in the control group (G1), where no fluoride gel was applied. It was significantly higher (p < 0.001) compared to all other groups. G2 (5.03 ± 1.43 µm), G3 (5.47 ± 0.63 µm, p = 0.918) and G4 (5.14 ± 0.82 µm, p > 0.999) showed the overall best protection from hydrochloric acid induced erosion. Enamel wear in G5 (6.64 ± 0.86 µm) was significantly higher compared to G2 (p = 0.028) and G4 (p = 0.047). Conclusions After 20 days of daily application, all investigated fluoride gels are able to significantly reduce gastroesophageal reflux induced loss of enamel.

Assessment of 2D ultrasound fluid volume estimation accuracy in different shaped objects: an in vitro study

2019 ◽  
Vol 61 (2) ◽  
pp. 253-259
Author(s):  
Iroshani Kodikara ◽  
Iroshini Abeysekara ◽  
Dhanusha Gamage ◽  
Isurani Ilayperuma
Keyword(s):  
Estimation Error ◽  
In Vitro Study ◽  
High Accuracy ◽  
Volume Estimation ◽  
Estimation Accuracy ◽  
Rater Agreement ◽  
Actual Volume ◽  
2D Ultrasound ◽  
One Way Anova

Background Volume estimation of organs using two-dimensional (2D) ultrasonography is frequently warranted. Considering the influence of estimated volume on patient management, maintenance of its high accuracy is empirical. However, data are scarce regarding the accuracy of estimated volume of non-globular shaped objects of different volumes. Purpose To evaluate the volume estimation accuracy of different shaped and sized objects using high-end 2D ultrasound scanners. Material and Methods Globular (n=5); non-globular elongated (n=5), and non-globular near-spherical shaped (n=4) hollow plastic objects were scanned to estimate the volumes; actual volumes were compared with estimated volumes. T-test and one-way ANOVA were used to compare means; P<0.05 was considered significant. Results The actual volumes of the objects were in the range of 10–445 mL; estimated volumes ranged from 6.4–425 mL ( P=0.067). The estimated volume was lower than the actual volume; such volume underestimation was marked for non-globular elongated objects. Regardless of the scanner, the highest volume estimation error was for non-globular elongated objects (<40%) followed by non-globular near-spherical shaped objects (<23.88%); the lowest was for globular objects (<3.6%). Irrespective of the shape or the volume of the object, volume estimation difference among the scanners was not significant: globular (F=0.430, P=0.66); non-globular elongated (F=3.69, P=0.064); and non-globular near-spherical (F=4.00, P=0.06). A good inter-rater agreement (R=0.99, P<0.001) and a good correlation between actual versus estimated volumes (R=0.98, P<0.001) were noted. Conclusion The 2D ultrasonography can be recommended for volume estimation purposes of different shaped and different sized objects, regardless the type of the high-end scanner used.

scholarly journals Impact of refrigeration on the surface hardness of hybrid and microfilled composite resins

2009 ◽  
Vol 20 (1) ◽  
pp. 42-47 ◽  
Author(s):  
Fernando Henrique Ruppel Osternack ◽  
Danilo Biazzetto de Menezes Caldas ◽  
Rodrigo Nunes Rached ◽  
Sérgio Vieira ◽  
Jeffrey A. Platt ◽  
...  
Keyword(s):  
Room Temperature ◽  
Surface Hardness ◽  
In Vitro Study ◽  
Knoop Hardness ◽  
Composite Resins ◽  
Bottom Surface ◽  
Steel Mold ◽  
Polymerization Condition ◽  
Post Hoc

This in vitro study evaluated the Knoop hardness of the composite resins Charisma® (C) and Durafill VS® (D) polymerized in 3 different conditions: at room temperature (A) (23 ± 1°C); refrigerated at 4 ± 1°C and immediately photo-activated after removal from the refrigerator (0); and, refrigerated at 4 ± 1°C and photo-activated after a bench time of 15 min at room temperature (15). One hundred and twenty specimens (4 mm diameter and 2 mm depth) were made using a stainless steel mold and following manufacturer's instructions. All specimens were tested immediately after polymerization (I) and after 7 days of water storage in the dark at room temperature (7d). The data were subjected to ANOVA and post-hoc Tukey's test (a=0.05). On the top surface, CAI was statistically similar to C15I and DAI to D15I (p>0.05). On the bottom surface, CAI presented higher hardness values when compared to COI and C15I (p<0.05). The D groups showed no significant differences (p>0.05) on the bottom surfaces for any tested polymerization condition. After 7 days of storage, the Knoop hardness decreased significantly (p<0.05) for groups C7d and D7d except for C07d, which was not different from COI at either surface (p>0.05). D07d showed higher Knoop hardness (p<0.05) values on the top surface when compared to the other groups.

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