scholarly journals New Resin-Based Bulk-Fill Composites: in vitro Evaluation of Micro-Hardness and Depth of Cure as Infection Risk Indexes

Materials ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1308 ◽  
Author(s):  
Marco Colombo ◽  
Simone Gallo ◽  
Claudio Poggio ◽  
Vittorio Ricaldone ◽  
Carla Renata Arciola ◽  
...  
Keyword(s):  
Bacterial Colonization ◽  
Soft Drink ◽  
In Vitro Study ◽  
Internal Surface ◽  
Micro Hardness ◽  
Depth Of Cure ◽  
Hardness Tester ◽  
Hardness Ratio ◽  
Internal Side

The current in vitro study evaluated the Vickers hardness number (VHN) and hardness ratio of four bulk-fill composites (VisCalor bulk; Admira Fusion x-tra; x-tra fil; and GrandioSO x-tra-Voco, Cuxhaven, Germany) to assess the risk of bacterial colonization in comparison with standard composite materials. Thirty samples were prepared for each group. The VHN of both the external (top) and internal surface (bottom) was determined with a micro-hardness tester (200 g load for 15 s), and the hardness ratio was also calculated for each sample. Subsequently, storage in an acidic soft drink (Coca-Cola, Coca-Cola Company, Milano, Italy) was performed; for each group, 10 samples were stored for 1 day, while another 10 were stored for 7 days and the remaining 10 were kept in water as controls. A significant reduction in VHN was shown for all the groups when comparing the external versus internal side (P < 0.05), although the hardness ratio was greater than 0.80, resulting in an adequate polymerization. Regarding the acid storage, all the groups showed a significant decrease of VHN when compared with the controls, both after 1 day (P < 0.05) and after 7 days (P < 0.001). All the products showed adequate depth of cure without further risk of bacterial colonization. However, acid exposure negatively affected micro-hardness values, which might promote subsequent colonization.

scholarly journals In Vitro Re-Hardening of Bleached Enamel Using Mineralizing Pastes: Toward Preventing Bacterial Colonization

Materials ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 818 ◽  
Author(s):  
Andrea Scribante ◽  
Claudio Poggio ◽  
Simone Gallo ◽  
Paolo Riva ◽  
Antonella Cuocci ◽  
...  
Keyword(s):  
Bacterial Colonization ◽  
Micro Hardness ◽  
Home Agent ◽  
Vickers Hardness Number ◽  
Hardness Tester ◽  
Post Hoc ◽  
To Receive ◽  
Hardness Values ◽  
At Home

The search for materials able to remineralize human hard tissues is a modern medical challenge. In this study, the protective effect on the enamel microhardness by a paste based on hydroxyapatite and sodium fluoride (Remin Pro) was evaluated after two different enamel bleaching procedures. Forty sound human incisors were randomly assigned to different treatments: bleaching with an in-office agent (Perfect Bleach Office+); bleaching with an at-home agent (Perfect Bleach); bleaching with the in-office agent followed by the prophylaxis paste; bleaching with the at-home agent followed by the prophylaxis paste; no treatment (control). Bleaching was performed at 0, 8, 24 and 32 h, followed by a 3-min re-mineralizing treatment in the subgroups designed to receive it. Specimens underwent a micro-hardness tester and a mean Vickers Hardness number was considered for each specimen. ANOVA exhibited significant differences among groups. Post-hoc Tukey testing showed significant micro-hardness decrease after the application of both the two bleaching agents. The treatment with prophylaxis paste significantly increased the micro-hardness values of bleached enamel.

Comparative Evaluation of microhardness of type 2 Glass Ionomer Cement (restorative) and Zirconia based GIC - An In-Vitro Study

2015 ◽  
Vol 7 (1) ◽  
pp. 4-7
Author(s):  
Prakash Lokhande
Keyword(s):  
Comparative Evaluation ◽  
Glass Ionomer Cement ◽  
In Vitro Study ◽  
Type Ii ◽  
Glass Ionomer ◽  
Micro Hardness ◽  
Hardness Tester ◽  
Ionomer Cement

Abstract Aims To evaluate the microhardness of type II glass-ionomer cement (GIC) (restorative) and zirconia based glass –ionomer cement. Materials and Methods Twenty cylindrical samples measuring 5mm (diameter) and 5mm in length were prepared with type II glass-ionomer cement that is restorative (n=10) and zirconia based glass-ionomer-cement (n=10). Finishing and polishing was made with coarse grit to fine grit. Then samples were subjected to Vickers hardness tester by using digital micro hardness tester (Zwick/Roell) under a load of 300 grams for 15 seconds. The data obtained was subjected to statistical analysis and unpaired‘t’ test was used to compare the micro hardness between two groups. Result Zirconia based glass-ionomer cements showed better micro hardness values as compared to that of type II glass-ionomer cement (restorative). Conclusion Better material with increased hardness like zirconia based GIC should be used in today's clinical practice. Further studies should be carried out to check other physical properties of zirconia based GIC. How to cite this article Lokhande P, Shivanna V. Comparative evaluation of micro hardness of type 2 Glass Ionomer cement (restorative) and Zirconia based GIC- An in vitro study. CODS J Dent 2015;7:4-7

Evaluation of Intensity of LED Curing Light on the Depth of Cure of Composite- An in Vitro Study

2019 ◽  
Vol 10 (12) ◽  
pp. 2118
Author(s):  
A. G. Lakshmisree ◽  
Arumugam Karthick ◽  
Nagarajan Geethapriya ◽  
Arunajatesan Subbiya
Keyword(s):  
In Vitro Study ◽  
Vitro Study ◽  
Depth Of Cure ◽  
Curing Light

scholarly journals Effects of Groove Sealing of the Posterior Occlusal Surface and Offset of the Internal Surface on the Internal Fit and Accuracy of Implant Placements Using 3D-Printed Surgical Guides: An In Vitro Study

Polymers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1236
Author(s):  
Jung-Hwa Lim ◽  
Enkhjargal Bayarsaikhan ◽  
Seung-Ho Shin ◽  
Na-Eun Nam ◽  
June-Sung Shim ◽  
...  
Keyword(s):  
In Vitro Study ◽  
Internal Surface ◽  
Three Dimensions ◽  
Surface Shape ◽  
Digital Data ◽  
Surgical Guide ◽  
Implant Placement ◽  
Surgical Guides ◽  
Internal Fit

This study evaluated the internal fit and the accuracy of the implant placement position in order to determine how the surface shape of the tooth and the offset influence the accuracy of the surgical guide. The acquired digital data were analyzed in three dimensions using 3D inspection software. The obtained results confirmed that the internal fit was better in the groove sealing (GS) group (164.45 ± 28.34 μm) than the original shape (OS) group (204.07 ± 44.60 μm) (p < 0.001), and for an offset of 100 μm (157.50 ± 17.26 μm) than for offsets of 30 μm (206.48 ± 39.12 μm) and 60 μm (188.82 ± 48.77 μm) (p < 0.001). The accuracy of implant placement was better in the GS than OS group in terms of the entry (OS, 0.229 ± 0.092 mm; GS, 0.169 ± 0.061 mm; p < 0.001), apex (OS, 0.324 ± 0.149 mm; GS, 0.230 ± 0.124 mm; p < 0.001), and depth (OS, 0.041 ± 0.027 mm; GS, 0.025 ± 0.022 mm; p < 0.001). In addition, the entries (30 μm, 0.215 ± 0.044 mm; 60 μm, 0.172 ± 0.049 mm; 100 μm, 0.119 ± 0.050 mm; p < 0.001) were only affected by the amount of offset. These findings indicate that the accuracy of a surgical guide can be improved by directly sealing the groove of the tooth before manufacturing the surgical guide or setting the offset during the design process.

scholarly journals Erosive potential of three different commonly used pediatric syrups on deciduous teeth enamel: an in vitro study

2020 ◽  
Vol 7 (10) ◽  
pp. 2041
Author(s):  
Neha Thilak ◽  
Sundeep K. Hedge ◽  
Sham S. Bhat
Keyword(s):  
In Vitro Study ◽  
Titratable Acidity ◽  
Deciduous Teeth ◽  
Hardness Tester ◽  
Titrable Acidity ◽  
Group A ◽  
Group B ◽  
Post Hoc ◽  
Group D

Background: The aim of the study is to compare the erosive potential of three different commonly used pediatric syrups on deciduous teeth enamel. The objectives of the study were to assess the endogeneous pH and titratable acidity of mefenamic acid syrup (meftal P), cetrizine syrup (alerid) and multivitamin syrup (zincovit) and to evaluate the microhardness of the enamel after successive immersion cycles in each of the syrups.Methods: 40 non carious deciduous teeth were included for the study The samples were then randomly allocated into 4 groups (10 in each group): Group A- mefenemic acid syrup (meftal P), Group B- cetrizine syrup (alerid), group C- multivitamin syrup (zincovit) and group D- control (distilled water). The samples were then subjected to the immersion cycles in the syrups. Assessment of enamel surface microhardness was done using Vickers hardness tester at 7th day and 14th day. The pH and titrable acidity of the syrups were also assessed. One way analysis of variance (ANOVA) and post hoc tests were used for the statistical analysis.Results: Out of the test groups, group C showed the lowest pH of around 4.2 and exhibited the largest titrable acidity (22.8 ml) compared with 21 ml in group A and 15.5 ml in group B. At the end of 14th day, group A had microhardness of about 293.43.84±6.34, group B had 299.930±6.85, group C had 313.380±6.23 and group D had 334.190±5.51.Conclusions: All the pediatric liquid medications assessed in the study, meftal P, alerid and zincovit showed acidic pH, high titrable acidities and all the syrups showed loss of microhardness after exposure to the syrups for 14 days. Loss of microhardness was highest for meftal P followed by alerid and least for zincovit.

Sign in / Sign up

Export Citation Format

Share Document