Polymerization shrinkage: effects of constraint and filling technique in composite restorations

<sup>99m</sup>Tc in the evaluation of microleakage of composite resin restorations with SonicFill<sup>TM</sup>. An <i>in vitro</i> experimental model

“…Nevertheless the literature is not conclusive concerning the advantages promoted by the incremental technique. Versluis et al [28] and Loguercio et al [29] argue that the incremental filling technique produces higher polymerization stresses at the restoration interface compared with bulk fill. In this study it was found that the polymerization shrinkageis similar in both methods, since there was no statistically significant difference as regards microleakage with SonicFill TM and Filtek TM SupremeXTE.…”

“…The same operator performed all restorative procedures, to reduce human operator error, as some authors have recommended [10,17,20,30]. The specimens were stored in distilled water at 37˚C for one week [2,14] and after thermocycling 500 cycles between 5˚C and 55˚C with a dwell time of 30 seconds [10,22,29,31]. Composite restorations are exposed to various influences in the oral cavity, and therefore to evaluate microleakage meth-ods to reproduce these features are required.…”

Durability of Enamel Bonding Using Two-step Self-etch Systems on Ground and Unground Enamel

“…3 This is in agreement with previous literature findings, since no correlation between marginal sealing, micro-or nanoleakage with bond strength values measured immediately or over time has been established. 34,36 Several studies have reported resin-dentin bond degradation after water storage. [11][12][13] Hydrolysis of the interface components (resin and/or collagen) is usually blamed for such degradation.…”

Placing Dental Composites—A Stressful Experience

“…54,68,[73][74][75][76] The physical properties, such as elastic modulus and strength, also have been shown to be reduced for composites cured in cavities with greater external constraint, 74,77 though another study did not show this difference. 75 While these results may be directly attributable to the generation of contraction stresses in dental composite restorations, and they provide a rationale for closely following a structured placement technique to minimize their effects, no direct clinical evidence currently exists to support a cause and effect relationship between contraction stress and clinical failure or longevity for these materials.…”