Effect of casein phosphopeptide-amorphous calcium phosphate on surface roughness of a silorane-based and methacrylate-based composite resin : in vitro comparative study

Abstract EN

Background : when using a fluoridated agent for caries-preventive intervention, the clinician should be careful not to allow the agent to come into contact with the composite restorations since topically applied fluorides were found to induce adverse effects on the morphologic characteristics and composition of composite restorations.

A new demineralizing agent "MI Paste" and its fluoridated form "MI Paste Plus" based on Recaldent technology (CPP-ACP) were developed.

This study was conducted with the aim of assessing the effect of these new demineralizing agents on surface roughness of two types of composite resin materials.

Materials and Method : cylindrical specimens 12mm in diameter and 2mm in height were prepared from two types of composite resin materials : Filtek™ P90 (a silorane-based composite material) and Filtek™ Z350 XT (a methacrylate based Nano fill composite material).

Each specimen was cured against a celluloid strip in a specially designed cylindrical mold using a QTH light curing unit for 40 seconds.

Forty specimens were prepared for each composite type and subdivided into four subgroups of ten specimens each : Subgroup 1 : without treatment, dry-stored in an incubator at 37οC for one week (control subgroup), Subgroup 2 : without treatment, stored in deionized water in an incubator at 37οC for one week, Subgroup 3 : treated with MI Paste once daily for one week, and Subgroup 4 : treated with MI Paste Plus once daily for one week.

Surface roughness of the specimens was obtained with a surface profile testing machine, which used the roughness average (Ra) to assess surface changes.

Several measurements were taken for each specimen and the mean value of these measurements on one specimen was regarded as the Ra of that specimen.

The mean Ra value of each subgroup was then calculated.

Results : the results of this study showed statistically non-significant differences among the different subgroups of Filtek™ P90 composite resin material.

Concerning Filtek™ Z350 XT composite resin material, the results showed a statistically highly significant difference in surface roughness between the subgroup stored in deionized water and the control one, with statistically non-significant difference between the subgroups treated with MI Paste and MI Paste Plus and the control subgroup.

Comparison of significance between the corresponding subgroups of both composite types revealed statistically non-significant differences except for subgroup 2 which showed a statistically significant higher surface roughness in Filtek™ Z350 XT than Filtek™ P90.

Conclusions : the daily application of the MI Paste and MI Paste Plus for one week had non-significant effect on surface roughness of the silorane-based composite resin material Filtek™ P90.

On the other hand, the application of these agents caused surface smoothening of the Nano filled methacrylate-based composite resin material Filtek.

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