scholarly journals The Influence of Cement Layer Thickness on the Stress State of Metal Inlay Restorations—Photoelastic Analysis

Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 599
Author(s):  
Grzegorz Sokolowski ◽  
Michal Krasowski ◽  
Agata Szczesio-Wlodarczyk ◽  
Bartlomiej Konieczny ◽  
Jerzy Sokolowski ◽  
...  

The successful restoration of teeth requires a good connection between the inlay and natural tissue. A strong bond may improve retention and reinforce tooth structure. The purpose of this study was to evaluate the influence of cement layer thickness on contraction stress generated during photopolymerization, and to determine the changes in stress state of the cement occurring during aging in water (over 84 days). Two cements were used: resin composite cement (NX3) and self-adhesive resin cement (Maxcem Elite Chroma). A cylindrical sample made of CuZn alloy was used to imitate the inlay. The stress state was measured by photoelastic analysis. The contraction stress of the inlay restoration was calculated for cement layer thicknesses of 25 µm, 100 µm, 200 µm, and 400 µm. For both tested materials, the lowest contraction stress was observed for the thinnest layer (25 µm), and this increased with thickness. Following water immersion, a significant reduction in contraction stress was observed due to hygroscopic expansion. Applying a thin layer (approximately 25 µm) of composite and self-adhesive resin cements resulted in high levels of expansion stresses (over −6 MPa) after water aging.

2016 ◽  
Vol 27 (5) ◽  
pp. 592-598 ◽  
Author(s):  
Regina Maria Helen-Cot Marcos ◽  
◽  
Gustavo Ross Kinder ◽  
Edson Alfredo ◽  
Tarcisio Quaranta ◽  
...  

Abstract The objective of the present study was to evaluate the influence of resin cement thickness on the bond strength of prefabricated and customized glass fiber posts after storage in distilled water. Thirty human uniradicular roots were treated endodontically. The roots were divided into 3 groups: THIN (thin cement layer) - post space preparation with #0.5 drill and cementation of #0.5 post; THICK (thick cement layer) - post space preparation with #1 drill and cementation of #0.5 post; and CUSTOM (customized cement layer) - post space preparation with #1 drill and cementation of a customized post (#0.5 glass fiber posts customized with resin composite). All posts were luted with self-adhesive resin cement. The push-out test was carried out after storage for 24 h and 90 days in distilled water at 37 °C. The data were analyzed with three-way ANOVA and Tukey's test (a=0.05). Bond strengths were significantly higher for CUSTOM (9.37 MPa), than for THIN (7.85 MPa) and THICK (7.07 MPa), which were statistically similar. Considering the thirds, the bond strength varied in the sequence: apical (7.13 MPa) < middle (8.22 MPa) = coronal (8.94 MPa). Bond strength for 24 h storage was significantly higher (8.80 MPa) than for 90-day storage (7.40 MPa). It may be concluded that the thickness of resin cement influenced the bond strength of glass fiber posts. The customized posts presented higher bond strength. Storage in water for 90 days affected negatively the values of bond strength, especially for thick cement layers in the apical third.


Polymers ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 1093
Author(s):  
Krzysztof Sokolowski ◽  
Agata Szczesio-Wlodarczyk ◽  
Kinga Bociong ◽  
Michal Krasowski ◽  
Magdalena Fronczek-Wojciechowska ◽  
...  

Ion-releasing polymeric restorative materials seem to be promising solutions, due to their possible anticaries effect. However, acid functional groups (monomers) and glass filler increase hydrophilicity and, supposedly, water sorption. The purpose of the study was to evaluate the influence of water sorption of polymeric materials on the stress state at the restoration-tooth interface. Beautifil Bulk Fill Flow, Beautifil Flow Plus F00, Beautifil Flow F02, Dyract eXtra, Compoglass Flow, Ionosit, Glasiosite, TwinkiStar, Ionolux and Fuji II LC were used for the study. The stress state was measured using photoelastic analysis after: 0.5, 24, 72, 96, 168, 240, 336, 504, 672, 1344 and 2016 h. Moreover, water sorption, solubility and absorption dynamic were assessed. The water sorption, solubility and absorption dynamic of ion-releasing restorative materials are material dependent properties. The overall results indicated that the tested restorative materials showed significant stress decrease. The total reduction in contraction stress and water expansion stress was not observed for materials with low value of water sorption (Beautifil Bulk Fill, Dyract eXtra, Glasionosit and Twinky Star). The photoelastic method turned out to be inadequate to evaluate stress changes of resin modified glass-ionomer cement (RMGI, Fuji II LC and Ionolux).


2020 ◽  
Vol 45 (4) ◽  
pp. E185-E195
Author(s):  
RV Machry ◽  
PE Fontana ◽  
TC Bohrer ◽  
LF Valandro ◽  
OB Kaizer

Clinical Relevance When luting relined fiber posts with self-adhesive cement, the surface treatment of the posts influences the adhesion of the fiber posts to root dentin. SUMMARY This study evaluated the effect of surface treatment and silanization of resin composite on the bond strength of relined fiber posts cemented with self-adhesive resin cement. Push-out and microtensile bond strength (MTBS) tests were performed in this study. The endodontic treatment of 80 single-rooted bovine teeth was first performed in the push- out test segment, followed by weakening the intracanal walls by diamond bur. Then, the glass fiber posts were adapted with resin composite to fill the root canals, followed by photoactivation and resin surface conditioning according to four different experimental conditions: no conditioning as control, 10% hydrofluoric acid, 35% hydrogen peroxide, or air abrasion with alumina particle (all groups were subdivided into “with silanization” or “without silanization,” thus totaling eight experimental groups). Self-adhesive resin cement was used for the post cementation. Four slices per tooth were obtained for the push-out tests. Next, 160 blocks of resin composite were first produced for the MTBS tests; their bonding surfaces were conditioned (as mentioned, ie, eight treatments), and they were cemented to each other. The 80 sets (n=10/treatment) were then cut into microbars (16/set): eight were immediately tested, while the other eight were thermocycled (12,000×) and stored (120 days) before MTBS. Failure modes and topographic analyses were performed after treatments. There was no statistically significant difference for the push-out results. In MTBS, surface treatment and silanization had a significant effect (p&lt;0.001). Aging decreased bond strength for all groups. Considering the aged groups, air abrasion promoted the highest values and silanization improved bond strength for all treatments except air abrasion. The alumina particle air abrasion of the relining resin composite promoted the highest bond strengths when luting with self-adhesive resin cement.


1997 ◽  
Vol 13 (3) ◽  
pp. 146-150 ◽  
Author(s):  
Darja Alster ◽  
Albert J. Feilzer ◽  
Anton J. de Gee ◽  
Carel L. Davidson

Materials ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 3517
Author(s):  
Raffaele Cesca ◽  
Vera Colombo ◽  
Bruna Ernst ◽  
Luigi Maria Gallo ◽  
Mutlu Özcan

Perio-overdenture design helps to reduce periodontal diseases and secondary caries on abutment teeth. Composite copings can be cemented adhesively to the abutment teeth with different techniques. In this study, direct/indirect resin composite copings for perio-overdentures, luted using different adhesive cementation modalities were compared. Human teeth (N = 40) were prepared to receive spherical attachment copings and randomly divided into four groups: (1) resin-composite copings bonded directly (DC), (2) composite copings made indirectly, luted with dual-polymerized resin cement (ICV), (3) composite copings made indirectly, bonded with resin composite (ICT), (4) composite copings made indirectly, bonded with resin composite after the immediate dentin sealing method (IDS). Specimens were tested for tensile failure and one-way ANOVA (alpha = 0.05) was performed and the two-parameter Weibull modulus, scale (m) and shape (0) were calculated. Mean tensile load (N) was significantly higher for Group IDS (238 ± 81) than for the other groups (144 ± 53–184 ± 46) (p < 0.05). Group IDS (0.54 ± 0.25 mm) showed significantly higher deformation (mm) than other groups (0.2 ± 0.1–0.32 ± 0.15) (p < 0.05). Weibull distribution presented lower shape (0) for DC (3.33) compared to other groups (3.57–4.99). Cohesive coping failures were more frequent in Group IDS (60%) and mixed failures in other groups (40–60%). In conclusion, IDS copings could be preferred over other fabrication and adhesion modalities.


2016 ◽  
Vol 95 (13) ◽  
pp. 1487-1493 ◽  
Author(s):  
N. Hirose ◽  
R. Kitagawa ◽  
H. Kitagawa ◽  
H. Maezono ◽  
A. Mine ◽  
...  

An experimental cavity disinfectant (ACC) that is intended to be used for various direct and indirect restorations was prepared by adding an antibacterial monomer 12-methacryloyloxydodecylpyridinum bromide (MDPB) at 5% into 80% ethanol. The antibacterial effectiveness of ACC and its influences on the bonding abilities of resin cements were investigated. To examine the antibacterial activity of unpolymerized MDPB, the minimum inhibitory and bactericidal concentrations (MIC and MBC) were determined for Streptococcus mutans, Lactobacillus casei, Actinomyces naeslundii, Parvimonas micra, Enterococcus faecalis, Fusobacterium nucleatum, and Porphyromonas gingivalis. Antibacterial activities of ACC and the commercial cavity disinfectant containing 2% chlorhexidine and ethanol (CPS) were evaluated by agar disk diffusion tests through 7 bacterial species and by MIC and MBC measurement for S. mutans. The effects of ACC and CPS to kill bacteria in dentinal tubules were compared with an S. mutans–infected dentin model. Shear bond strength tests were used to examine the influences of ACC on the dentin-bonding abilities of a self-adhesive resin cement and a dual-cure resin cement used with a primer. Unpolymerized MDPB showed strong antibacterial activity against 7 oral bacteria. ACC produced inhibition zones against all bacterial species similar to CPS. For ACC and CPS, the MIC value for S. mutans was identical, and the MBC was similar with only a 1-step dilution difference (1:2). Treatment of infected dentin with ACC resulted in significantly greater bactericidal effects than CPS ( P < 0.05, analysis of variance and Tukey’s honest significant difference test). ACC showed no negative influences on the bonding abilities to dentin for both resin cements, while CPS reduced the bond strength of the self-adhesive resin cement ( P < 0.05). This study clarified that the experimental cavity disinfectant containing 5% MDPB is more effective in vitro than the commercially available chlorhexidine solution to eradicate bacteria in dentin, without causing any adverse influences on the bonding abilities of resinous luting cements.


2016 ◽  
Vol 42 (12) ◽  
pp. 1819-1821 ◽  
Author(s):  
Stephanie Lemos Martins Sicuro ◽  
Marilisa Carneiro Leão Gabardo ◽  
Carla Castiglia Gonzaga ◽  
Nathaly Dias Morais ◽  
Flares Baratto-Filho ◽  
...  

10.2341/08-73 ◽  
2009 ◽  
Vol 34 (2) ◽  
pp. 223-229 ◽  
Author(s):  
A. O. Spazzin ◽  
D. Galafassi ◽  
A. D. de Meira-Júnior ◽  
R. Braz ◽  
C. A. Garbin

Clinical Relevance According to finite element analysis, the zirconia ceramic post created higher stress levels in the post and slightly less in dentin compared with glass fiber posts. Resin cement with a high elastic modulus created higher stress levels in the cement layer. The different film thicknesses of cement did not create significant changes in stress levels.


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