Minimizing Dentinal Fluid Flow Associated with Gap Formation

2006 ◽  
Vol 85 (11) ◽  
pp. 1027-1031 ◽  
Author(s):  
D.N. Ratih ◽  
J.E.A. Palamara ◽  
H.H. Messer

The relationship between gap formation and outward fluid flow and procedures to minimize both phenomena were investigated in extracted human premolars restored in vitro with MOD composite restorations. We hypothesized that either glass-ionomer cement (GIC) liners or low-shrinkage composite could reduce fluid flow related to gap formation. Two groups restored with bonding agents with either high- or low-shrinkage resin composites, and 2 groups restored by either conventional or light-cured GIC liner plus resin composite were compared (8 teeth/group). Fluid flow was measured with an automated apparatus. Baseline fluid flow was low and unchanged after bonding, but increased sharply (though transiently) after teeth were lined with GIC. Outward flow was significantly greater with conventional than with light-cured GIC. Inward fluid flow occurred during light-curing, followed by extensive, prolonged outward flow after curing. Low-shrinkage composite or GIC liners reduced gap formation and limited outward fluid flow. GIC liners promoted outward fluid flow during their setting reactions. Abbreviations: GIC, glass-ionomer cement; CEJ, cemento-enamel junction; MOD, mesio-occluso-distal; SEM, scanning electron microscopy.

Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1700
Author(s):  
Atsushi Kameyama ◽  
Aoi Saito ◽  
Akiko Haruyama ◽  
Tomoaki Komada ◽  
Setsuko Sugiyama ◽  
...  

This study aimed to examine the marginal seal between various commercial temporary restorative materials and exposed dentin/built-up composite. Sixty bovine incisors were cut above the cemento-enamel junction, and half of the dentin was removed to form a step, which was built up using flowable resin composite. The root canals were irrigated, filled with calcium hydroxide, and sealed using one of six temporary sealing materials (hydraulic temporary restorative material, temporary stopping material, zinc oxide eugenol cement, glass-ionomer cement, auto-cured resin-based temporary restorative material, and light-cured resin-based temporary restorative material) (n = 10 for each material). The samples were thermocycled 500 times and immersed in an aqueous solution of methylene blue. After 2 days, they were cut along the long axis of the tooth and the depth of dye penetration was measured at the dentin side and the built-up composite side. For the margins of the pre-endodontic resin composite build-up, the two resin-based temporary restorative materials showed excellent sealing. Hydraulic temporary restorative material had a moderate sealing effect, but the sealing effect of both zinc oxide eugenol cement and glass-ionomer cement was poorer.


2013 ◽  
Vol 37 (4) ◽  
pp. 403-406 ◽  
Author(s):  
S Tamilselvam ◽  
MJ Divyanand ◽  
P Neelakantan

Objective: This aim of this study was at compare the fibroblast cytotoxicicty of four restorative materials - a conventional glass ionomer cement (GC Fuji Type II GIC), a ceramic reinforced glass ionomer cement (Amalgomer), a giomer (Beautifil II) and a resin composite (Filtek Z350) at three different time periods (24, 48 and 72 hours). Method: The succinyl dehydrogenase (MTT) assay was employed. Cylindrical specimens of each material (n=15) were prepared and stored in Dulbecco's modified Eagle medium, following which L929 fibroblasts were cultured in 96 well plates. After 24 hours of incubation, the MTT assay was performed to detect the cell viability. The method was repeated after 48 and 72 hours. The impact of materials and exposure times on cytotoxicity of fibroblasts was statistically analyzed using two way ANOVA (P=0.05). Results: Both time and material had an impact on cell viability, with giomer demonstrating the maximum cell viability at all time periods. The cell viability in the giomer group was significantly different from all other materials at 24 and 72 hours (P<0.05), while at 48 hours giomer was significantly different only with resin composite (P<0.05). Conclusions: Giomers showed better biocompatibility than conventional and ceramic reinforced glass ionomer cements and, resin composite. Ceramic reinforced glass ionomer demonstrated superior biocompatibility compared to conventional glass ionomer.


Author(s):  
AlSarheed M ◽  
Salama F

Background: The purpose of this in vitro study was to evaluate the effect of finishing/polishing procedures on color stability of three restorative materials: Nano-hybrid resin composite (NRC), silver glass ionomer cement (SGI), and resin-modified glass ionomer cement (RMGI) exposed to different staining of energy drinks: Barbican, Bison, and Red bull.


RSBO ◽  
2017 ◽  
Vol 14 (2) ◽  
pp. 67-73
Author(s):  
Juan Fernando Ordoñéz-Aguilera ◽  
Rafael Massunari Maenosono ◽  
Denise Ferracioli Oda ◽  
Heitor Marques Honório ◽  
Rafael Francisco Lia Mondelli ◽  
...  

The use of a protective cervical barrier (PCB) is very well established to perform a safe internal bleaching; however, there is still no consensus on which material has the best sealing ability. Objective: This in vitro study aimed to evaluate the apical and linear sealing of different PCB materials placed during internal bleaching. Material and methods: This study had two study factors: PCB positioning, divided at two levels (cement-enamel junction [CEJ] and 1mm above the cement enamel junction [CEJ+1]); and PCB material, divided at eight levels (resin composite [RC], glass ionomer cement [GIC], resin-modified glass ionomer cement liner [LRGIC], restorative resin-modified glass ionomer cement [RRGIC], zinc phosphate cement [ZPC], eugenol-free zinc oxide cement [ZOC], provisional filling resin [PFR] and gutta-percha as control [GUT]). Response variables were apical and linear sealing obtained through dye penetration and analyzed with a digital microscope. Data were subjected to two-way analysis of variance followed by Tukey test (p<0.05). Results: The main factor for both apical and linear sealing was the type of material (p<0.01) regardless of their position. RC and ZPC presented the worst sealing values (p<0.05). The Spearman rank correlation coefficient revealed a positive correlation between the apical and linear leakage. Conclusion: The results suggest that RC and ZPC must be avoided as a PCB during internal bleaching procedures.


RSBO ◽  
2017 ◽  
Vol 1 (2) ◽  
pp. 67
Author(s):  
Juan Fernando Ordoñéz-Aguilera ◽  
Rafael Massunari Maenosono ◽  
Denise Ferracioli Oda ◽  
Heitor Marques Honório ◽  
Rafael Francisco Lia Mondelli ◽  
...  

The use of a protective cervical barrier (PCB) is very well established to perform a safe internal bleaching; however, there is still no consensus on which material has the best sealing ability. Objective: This in vitro study aimed to evaluate the apical and linear sealing of different PCB materials placed during internalbleaching. Material and methods: This study had two study factors: PCB positioning, divided at two levels (cement-enamel junction [CEJ] and 1mm above the cement enamel junction [CEJ+1]); and PCB material, divided at eight levels (resin composite [RC], glass ionomer cement [GIC], resin-modified glass ionomer cement liner [LRGIC], restorative resin-modified glass ionomer cement [RRGIC], zinc phosphate cement [ZPC], eugenol-free zinc oxide cement [ZOC],provisional filling resin [PFR] and gutta-percha as control [GUT]). Response variables were apical and linear sealing obtained through dye penetration and analyzed with a digital microscope. Data were subjected to two-way analysis of variance followed by Tukey test (p<0.05). Results: The main factor for both apical and linear sealing was the type of material (p<0.01), regardless of their position. RC and ZPC presented the worst sealing values (p<0.05). The Spearmanrank correlation coefficient revealed a positive correlation between the apical and linear leakage. Conclusion: The results suggest that RC and ZPC must be avoided as a PCB during internal bleaching procedures.


2018 ◽  
Vol 69 (11) ◽  
pp. 3013-3017
Author(s):  
Roxana Oancea ◽  
Anca Mesaros ◽  
Octavia Iulia Balean ◽  
Angela Codruta Podariu

The aim of this in vitro study was to test the effectiveness of applying the fluoride varnish on bracketed teeth with 2 types of bonding agent. 10 patients aged 12-18 (mean age 13.06 +/- 1.72 years) were scheduled to have the four fist premolar teeth extracted. The teeth were dived in 4 groups: 2 experimental and 2 controls. The teeth were cut in half so 80 surfaces were analyzed. The brackets were collated with Transbond XT and Fuji Ortho Lc. For each of the materials that have been used there was a test and a control group. The tests groups received one single application of Duraphat. The content in fluoride was measured by spectrophotometer. The mean values of fluoride indicated an important increase in the fluoride content after using resin modified glass ionomer cement and fluoride varnish. Statistically significant differences were determined between each of the control and treatment group when both materials have been used, after 10 days and one month application of the varnish. The study pointed out that the fluoride varnish combined with resin modified glass ionomer cement is more efficient than the classical resin composite in preventing demineralization around orthodontic brackets.


Author(s):  
Shruti Patil ◽  
Mallikarjun Goud ◽  
Girija Sajjan

ABSTRACT Purpose Fluorides are probably the most commonly used anticaries agents. Due to this property they are incorporated into various restorative materials. The rate and amount of fluoride release, however, vary for different materials, which in turn determines the effectiveness of the restorative material in preventing demineralization around the restoration. To evaluate the fluoride release and area of demineralization of resin modified glass ionomers and compomers, and compare them with conventional glass ionomer cement and also to evaluate the relationship between the fluoride release and demineralization. Materials and methods A total of 32 human incisors were chosen and sectioned horizontally at CEJ, and the middle 2 mm of facial enamel isolated and restored with the test materials: Conventional glass ionomer cement (GIC), resin modified glass ionomer cement (RMGIC), compomer and resin composite. The specimens were observed under polarized light microscope with image analyzer to measure the area and depth of demineralization. For fluoride release study, disks of test materials were suspended in deionized water and fluoride release was measured till a period of 4 days. Results The area and depth of demineralization were least around the GIC, followed by RMGIC, compomer and composite (p < 0.05). A negative correlation was found between fluoride release and demineralization which was, however, not statistically significant. Conclusion The 4-day fluoride release was also higher for GIC as compared to RMGIC and Compomer.


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