Polymerisation shrinkage around composite resin restorations--an in vitro study

Area of Science:

• Dental Materials Science
• Restorative Dentistry
• Biomaterials

Background:

• Composite resins are widely used for posterior restorations.
• Microleakage at the tooth-restoration interface can lead to secondary caries and restoration failure.
• Understanding adhesive penetration into polymerization contraction gaps is crucial for assessing marginal integrity.

Purpose of the Study:

• To evaluate the degree of fluorescent adhesive penetration at the margins of three posterior composite resin restorative materials.
• To compare the marginal integrity of Fulfil, Estilux Posterior, and P 50 composite resins.
• To investigate the relationship between polymerization contraction gaps and adhesive penetration.

Main Methods:

• Seventy-eight extracted human premolars underwent Class II cavity preparation.
• Cavities were restored with one of three composite resin brands (Fulfil, Estilux Posterior, P 50).
• Fluorescent adhesive was applied to restoration margins, teeth were sectioned, and examined under fluorescent light to assess gap penetration.

Main Results:

• Fluorescent adhesive penetrated polymerization contraction gaps in all three composite resin brands to varying degrees.
• Observed defects were similar across all three brands.
• Statistical analysis revealed no significant differences in the degree of adhesive penetration between the brands (p > 0.05).

Conclusions:

• All tested posterior composite resins exhibited some degree of contraction gap formation.
• The tested brands demonstrated similar marginal integrity concerning adhesive penetration into contraction gaps.
• Further research may explore long-term clinical performance and different adhesive systems.