A comparison of resin-modified glass-ionomer and resin composite polymerisation shrinkage stress in a wet environment

详细信息    查看全文

• 作者：Joshua J. Cheetham ; Joseph E.A. Palamara ; Martin J. Tyas ; Michael F. Burrow
• 关键词：Resin-modified glass-ionomer ; Resin composite ; Polymerisation shrinkage stress ; Polymerisation contraction stress
• 刊名：Journal of the Mechanical Behavior of Biomedical Materials
• 出版年：January, 2014
• 年：2014
• 卷：29
• 期：Complete
• 页码：33-41
• 全文大小：1639 K

文摘

Objective

The aim of this study was to investigate the polymerisation shrinkage stress under water of four resin-modified glass-ionomers and three resin composite materials.

Methods

Transparent acrylic rods (5 mm diameter脳30 mm) were prepared and secured into drill chucks connected to a universal testing machine. A plastics cup was placed around the lower rod and a distance of 1.00 mm was established between the prepared surfaces which provided a C-factor of 2.5. For composite only, an adhesive layer (Scotchbond Universal Adhesive) was placed on the rod ends and cured to achieve a bond with the rod end. Materials were placed between the rods and a strain gauge extensometer was installed. Materials were light cured for 40 s and the plastics cup was filled with ambient temperature water. To determine polymerisation shrinkage stress (蟽_pol) three specimens of each material were tested for a 6-h period to determine mean maximum 蟽_pol (MPa), 蟽_pol rate (MPa/s) and final 蟽_pol (MPa). ANOVA and post hoc Tukey tests were used to determine significant differences between means.

Results

The highest mean maximum 蟽_pol of (5.4卤0.5) MPa was recorded for RMGIC and (4.8卤1.0) MPa for composite. The lowest mean final 蟽_pol of (0.8卤0.4) MPa was recorded for RMGIC. For mean maximum 蟽_pol, 蟽_pol rate and final 蟽_pol there were significant differences between materials within groups, although no significant difference (p>0.05) was observed when comparing the RMGIC group to the composite group.

Conclusion

When comparing mean 蟽_pol, maximum 蟽_pol, and 蟽_pol rates between individual RMGIC and composite materials significant differences (p<0.05) were observed. However when comparing the group RMGIC to composite no significant differences (p>0.05) were observed. The null hypothesis that there is no difference in the short term 蟽_pol of RMGIC materials when compared to composite materials is only partly rejected.

Relevance

Limited information is available on the comparison of RMGIC and resin composite 蟽_pol levels. This study provides information on the short term levels in a wet environment and will assist in understanding the initial 蟽_pol rates RMGIC place in cavities.