Evaluating Resin-Dentin Bond by Microtensile Bond Strength Test: Effects of Various Resin Composites and Placement Techniques

Abstract

Objectives:This in vitro study evaluated the microtensile bond strength (MTBS) of a methacrylate-based compared to a silorane-based resin composite in Class I cavity using different placement techniques.Materials and Methods:Class I cavities with dimension of (4 mm long, 4 mm wide, 3 mm deep) were prepared in extracted sound human molars. The teeth were randomly divided into six groups. The first three groups were filled with Filtek P90 using three methods of insertion; bulk, incremental and snow-plow, and the remaining three groups were filled with Clearfil AP-X using the same three placement techniques. After 24 hours of storage in water at 37°C, the specimens were thermocycled to 1000 cycles. Specimens were prepared for MTBS testing by creating bonded beams obtained from the pulpal floor. Statistical analysis used: Statistical analyses of data were performed by two-way ANOVA/Tukey (α=.05).Results:The experiment showed significant differences between the two resin composites with regard to filling techniques (P<0.05). The MTBS was significantly higher in each of Filtek P90 subgroup compared to Clearfil AP-X ones (P<0.05). With respect to filling technique in both resin composites, bulk insertion showed the significantly lowest MTBS (P<0.05), while no significant difference was found between the outcome of incremental and snow-plow techniques (P>0.05).Conclusion:Silorane-based resin composite as opposed to methacrylate based resin composite and layering placements in contrast to bulk filling method had higher microtensile bond strength.

Probing the hierarchy of evidence to identify the best strategy for placing class II dental composite restorations using current materials

“…While not directly assessing marginal integrity, resindentin bond strength was compared in another study for two composites placed in class I cavities in increments, or with the snowplow method, or in bulk. 57 For both composites, there was no difference in bond strength for the incremental and the snowplow method, but both were significantly higher than the bulk-fill method.…”

“…They assessed marginal adaptation with SEM and micro‐CT and found that the snowplow method produced fewer gaps than an oblique incremental technique, but similar to a horizontal increment method with conventional composite. While not directly assessing marginal integrity, resin‐dentin bond strength was compared in another study for two composites placed in class I cavities in increments, or with the snowplow method, or in bulk 57 . For both composites, there was no difference in bond strength for the incremental and the snowplow method, but both were significantly higher than the bulk‐fill method.…”

Subgingival = suboptimal? Die Proximal Box Elevation zur Therapie tiefer Defekte

“…Dabei ist es entscheidend, dass das visköse Komposit beispielsweise aus einem Cavifill in die Kavität und das dort bereits platzierte, nicht polymerisierte Flowable injiziert wird [33]. Der Verbund zum Dentin ist in Klasse-I-Kavitäten vergleichbar mit der klassischen Inkrement-Schichttechnik [34].…”

A perspective of marginal microleakage in class II composite resin restorations using different types and techniques: an in-vitro study

“…Factors that can influence stress formation in the matrix include volumetric polymerization shrinkage, adherence of the resin composite to the cavity walls, the elastic modulus, the flowability of the resin composite, and the cavity configuration factor (C-factor). 8 A new silorane-based composite resin-system based on the reaction between oxirane and siloxane molecules has been introduced. 9 The silorane system uses ring-opening polymerization instead of free-radical polymerization of dimethacrylate monomers.…”

“…It has been reported that silorane has <1% volumetric shrinkage and its mechanical properties were clinically successful and comparable to methacrylate-based composite materials, suggesting its use for dental restorations. 6,8,10,15 Many dental adhesive systems are being used to decrease unwanted effects of polymerization shrinkage and gaps formation. However, restorative dental materials can be affected by marginal microleakage at different levels especially in adhesion regions with enamel, dentin and cementum.…”