Influence of cavity dimensions and their derivatives (volume and ‘C’ factor) on shrinkage stress development and microleakage of composite restorations

2006 ◽  
Vol 22 (9) ◽  
pp. 818-823 ◽  
Author(s):  
R BRAGA ◽  
L BOARO ◽  
T KUROE ◽  
C AZEVEDO ◽  
J SINGER
Keyword(s):  
Shrinkage Stress ◽  
Stress Development ◽  
Composite Restorations

Marginal Adaptation of Direct Class II Composite Restorations with Different Cavity Liners

2013 ◽  
Vol 38 (6) ◽  
pp. E210-E220 ◽  
Author(s):  
R Pecie ◽  
I Onisor ◽  
I Krejci ◽  
T Bortolotto
Keyword(s):  
Elastic Modulus ◽  
Class Ii ◽  
Control Group ◽  
Shrinkage Stress ◽  
Marginal Adaptation ◽  
Composite Restorations ◽  
Significant Difference ◽  
Before And After ◽  
Group A ◽  
Group D

SUMMARY The aim of this study was to evaluate how cavity linings with different elastic modulus can influence the marginal adaptation (MA) of Class II composite restorations before and after thermo-mechanical loading. Materials and Methods: Forty Class II cavities with margins extending 1 mm below the cement-enamel junction were prepared in extracted human third molars. In each group except the control group, a lining material of 1-mm thickness was applied to the bottom of the cavity and polymerized before placing the resin composite Herculite XRV Ultra (group A: control; group B: Premise Flowable lining; group C: Herculite XRV Ultra lining; and group D: Optibond FL lining). MA was evaluated (with a scanning electron microscope) before and after loading (200,000 loading cycles). Statistical analysis was done using the Shapiro-Wilks test, the analysis of variance test, and Duncan post hoc test at p<0.05. Results: Before loading, the percentages of continuous margins in dentin were superior (p<0.05) for groups C and D (71.1% and 87.2%, respectively) compared to groups A and B (55.7% and 48.3%, respectively). After loading, group D (79.8%) was statistically superior in dentin compared to all of the other groups (43.6%, 35.9%, and 54.4%, respectively). In occlusal enamel, no significant difference was found between groups. The percentage of enamel fractures and the percentage of noncontinuous margins in proximal enamel were high, with no significant difference between liners. It can be concluded that for the materials used in this study, a 1-mm-thick lining with an extremely low elastic modulus (2-3 GPa) could redistribute shrinkage stress. The use of a flowable composite did not significantly improve MA.

Comparison of Internal Adaptation in Class II Bulk-fill Composite Restorations Using Micro-CT

2017 ◽  
Vol 42 (2) ◽  
pp. 203-214 ◽  
Author(s):  
SH Han ◽  
SH Park
Keyword(s):  
Class Ii ◽  
Ct Images ◽  
Shrinkage Stress ◽  
Micro Ct ◽  
Polymerization Shrinkage ◽  
Composite Restorations ◽  
Group 3 ◽  
Internal Adaptation ◽  
Group 5 ◽  
Group 2

SUMMARY Purpose: This study compared the internal adaptation of bulk-fill composite restorations in class II cavities and explored the relationship between internal adaptation and polymerization shrinkage or stress. Methods and Materials: Standardized mesio-occluso-distal cavities were prepared in 40 extracted human third molars and randomly divided into five groups (n=8). After having been applied by total-etch XP bond (Dentsply Caulk, Milford, DE, USA) and light curing, the teeth were restored with the following resin composites: group 1, Filtek Z350 (3M ESPE, St. Paul, MN, USA); group 2, SDR (Dentsply Caulk, Milford, DE, USA) + Z350; group 3, Venus Bulk Fill (Heraeus Kulzer, Dormagen, Germany) + Z350; group 4, Tetric N-Ceram Bulk Fill (Ivoclar Vivadent, Schaan, Liechtenstein); and group 5, SonicFill (Kerr, West Collins, Orange, CA, USA). After thermo-mechanical load cycling, cross-sectional microcomputerized tomography (micro-CT) images were taken. Internal adaptation was measured as imperfect margin percentage (IM%), which was the percentage of defective margin length relative to whole margin length. On the micro-CT images, IM% was measured at five interfaces. Linear polymerization shrinkage (LS) and polymerization shrinkage stress (PS) were measured on each composite with a custom linometer and universal testing machine. To explore the correlation of IM% and LS or PS, the Pearson correlation test was used. Results: The IM% of the gingival and pulpal cavity floors were inferior to those of the cavity walls. The IM% values of the groups were found to be as follows: group 5 ≤ groups 1 and 4 ≤ group 2 ≤ group 3. The correlation analysis showed that the p value was 0.006 between LS and IM% and 0.003 between PS and IM%, indicating significant correlations (p<0.05). Conclusion: Flowable bulk-fill composites had a higher IM% and polymerization shrinkage stress than did packable bulk-fill and hybrid composites. In class II composite restoration, the gingival floor of the proximal box and pulpal floor of the cavity had higher IM% than did the buccal and lingual walls of the proximal box. LS and PS, which were measured under compliance-allowed conditions, were significantly related to internal adaptation.

Repair of Dimethacrylate-Based Composite Restorations by a Silorane-Based Composite: A One-Year Randomized Clinical Trial

2012 ◽  
Vol 37 (5) ◽  
pp. E13-E22 ◽  
Author(s):  
DAV Popoff ◽  
TTA Santa Rosa ◽  
RC Ferreira ◽  
CS Magalhães ◽  
AN Moreira ◽  
...  
Keyword(s):  
Clinical Trial ◽  
Composite Resin ◽  
Clinical Performance ◽  
Controlled Clinical Trial ◽  
Shrinkage Stress ◽  
Clinical Criteria ◽  
Composite Restorations ◽  
Composite Resin Restorations ◽  
One Year ◽  
The One

SUMMARY Purpose To investigate clinical performance of a low-shrinkage silorane-based composite resin when used for repairing conventional dimethacrylate-based composite restorations. Background Despite the continued development of resin-based materials, polymerization shrinkage and shrinkage stress still require improvement. A silorane-based monomer system was recently made available for dental restorations. This report refers to the use of this material for making repairs and evaluates the clinical performance of this alternative treatment. Materials and Methods One operator repaired the defective dimethacrylate-based composite resin restorations that were randomly assigned to one of two treatment groups: control (n=50) repair with Adper SE Plus (3M/ESPE) and Filtek P60 Posterior Restorative (3M/ESPE), and test (n=50) repair with P90 System Adhesive Self-Etch Primer and Bond (3M/ESPE) and Filtek P90 Low Shrink Posterior Restorative (3M/ESPE). After one week, restorations were finished and polished. Two calibrated examiners (Kw≥0.78) evaluated all repaired restorations, blindly and independently, at baseline and one year. The parameters examined were marginal adaptation, anatomic form, surface roughness, marginal discoloration, postoperative sensitivity, and secondary caries. The restorations were classified as Alpha, Bravo, or Charlie, according to modified US Public Health Service criteria. Mann-Whitney and Wilcoxon tests were used to compare the groups. Results Of the 100 restorations repaired in this study, 93 were reexamined at baseline. Dropout from baseline to one-year recall was 11%. No statistically significant differences were found between the materials for all clinical criteria, at baseline or at one-year recall (p>0.05). No statistically significant differences were registered (p>0.05) for each material when compared for all clinical criteria at baseline and at one-year recall. Conclusions The hypothesis tested in this randomized controlled clinical trial was accepted. After the one-year evaluations, the silorane-based composite exhibited a similar performance compared with dimethacrylate-based composite when used to make repairs.

Influence of the Compliance and Layering Method on the Wall Deflection of Simulated Cavities in Bulk-fill Composite Restoration

2016 ◽  
Vol 41 (6) ◽  
pp. e183-e194 ◽  
Author(s):  
Y-J Kim ◽  
R Kim ◽  
JL Ferracane ◽  
I-B Lee
Keyword(s):  
Wall Thickness ◽  
Mold Wall ◽  
Flexural Modulus ◽  
The Other ◽  
Shrinkage Stress ◽  
Linear Variable Differential Transformer ◽  
Polymerization Shrinkage ◽  
Wall Deflection ◽  
Composite Restorations ◽  
Composite Restoration

SUMMARY The aim of this study was to investigate the effects of the layering method and compliance on the wall deflection of simulated cavities in bulk-fill and conventional composite restorations and to examine the relationships between the wall deflection and the polymerization shrinkage, flexural modulus, and polymerization shrinkage stress of composites. Six light-cured composites were used in this study. Two of these were conventional methacrylate-based composites (Filtek Z250 and Filtek Z350 XT Flowable [Z350F]), whereas four were bulk-fill composites (SonicFill, Tetric N-Ceram Bulk-Fill, SureFil SDR Flow [SDR], and Filtek Bulk-Fill). One hundred eighty aluminum molds simulating a mesio-occluso-distal cavity (6 W×8 L×4 D mm) were prepared and classified into three groups with mold wall thicknesses of 1, 2, and 3 mm. Each group was further subdivided according to the composite layering method (bulk or incremental layering). Linear variable differential transformer probes were used to measure the mold wall deflection of each composite (n=5) over a period of 2000 seconds (33.3 minutes). The polymerization shrinkage, flexural modulus, and polymerization shrinkage stress of the six composites were also measured. All groups with bulk filling exhibited significantly higher deflection compared with groups with incremental layering. The deflection decreased as mold wall thickness increased. The highest and lowest polymerization shrinkage stresses were recorded for Z350F (5.07 MPa) and SDR (1.70 MPa), respectively. The correlation between polymerization shrinkage and the mold wall deflection decreased with increasing wall thickness. On the other hand, the correlation between flexural modulus and the mold wall deflection increased with increasing wall thickness. For all groups, wall deflection correlated strongly with polymerization shrinkage stress.

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