In Vivo and In Vitro Evaluations of Microleakage Around Class I Amalgam and Composite Restorations

Abstract

This study evaluated and compared microleakage values of in vivo and in vitro placed Class I amalgam restorations with or without three different lining materials and posterior composite restorations with two dentin bonding agents. For the in vivo group, 72 standardized Class I cavities were prepared on the occlusal surfaces of molars scheduled for extraction. The test groups (n = 12) were: amalgam without lining (A), amalgam with cavity varnish (A+C), amalgam with Clearfil SE Bond (A+CSE), amalgam with Clearfil 2V (A+C2V), composite with Clearfil SE Bond (C+CSE) and composite with Protect Bond (C+PB). The restored teeth were extracted after seven days. The same grouping, materials and techniques were used in 72 extracted molars for the in-vitro part of the study. The specimens were immersed in basic fuchsin for 24 hours and sectioned. Microleakage was examined and scored at 20x magnification. Statistical analyses were performed with the Kruskal-Wallis and Mann-Whitney U-tests with the 5% level of significance. Overall, the in vivo and in vitro test groups were not different from each other. No significant differences in microleakage values were observed between the unlined and lined amalgam groups (p > 0.05). However, since lined amalgam restorations did not reveal any marginal leakage, the application of an adhesive bonding material under the amalgam restorations can be considered. In general, cavity varnish was not as effective as adhesive bonding agents in preventing microleakage in amalgam restorations. Composite restorations demonstrated higher leakage values than amalgam restorations (p < 0.05), except for A+C (p > 0.05) in the in vivo group. There was no significant difference between the two composite groups for in vitro and in vivo conditions (p > 0.05).

Influence of Hand Instrumentation and Ultrasonic Scaling on the Microleakage of various Cervical Restorations: An in vitro Study

“…43 Hence, low leakage scores in the amalgam restorations of the current investigation can be related to corrosion sealing of the zinc-containing alloy used in other studies. 29,43 Another reason for low amalgam microleakage scores may be due to low-dimensional changes of high copper alloy used in this study because high copper alloys show the lowest dimensional changes. 44 These results should be interpreted with caution since it is difficult to extrapolate the findings of this and other similar in vitro investigations to the behavior of these restorative materials in the oral environment.…”

“…[23][24][25][26][27][28] Although dental amalgam has many advantages as a restorative material, such as strength, durability, and ease of use, microleakage has been identified as a significant problem with amalgam due to interfacial gap formation, which can lead to tooth discoloration, pulp irritation, and secondary caries. 29,30 In spite of the fact that the validity of microleakage assessment as a predictor of the clinical performance of restorative materials is uncertain and no laboratory test can coincidentally mimic all the conditions encountered in the oral environment, it has been advocated that research should be focused on laboratory examinations. 31,32 Hence, the purpose of this study was to examine the marginal seal of class V glass ionomer, composite resin, and amalgam restorations after subjecting them to hand instrumentation and ultrasonic scaling.…”

Comparative Evaluation of Microleakage of Four Different Direct Restorative Materials (Amalgam, Bonded Amalgam, Packable Composite and Packable Composite With Flowable Composite Liner) in Class Ii Restorations Using Stereomicroscope - An in-Vitro Study.

“…Also, dentin is a moist tissue, making bonding with adhesive more unstable (Van Meerbeek & others, 2003). In addition, cementum /dentin is more porous, enhancing the permeability to dye penetration in relation to enamel [1].  Immediately after packing the amalgam, a rapid contraction may be observed, followed by a slower expansion, then a slight and slow contraction.…”

“…Bonding of resins to dentin is more difficult and less predictable than bonding to enamel because dentin includes fewer mineral but more organic and water content than enamel. A cohesive bond to dentin is achieved by diffusion of hydrophilic resins into and around the collagen fibers of etched intertubular dentin [1].…”

Secondary caries and microleakage

“…However, an alternative approach has been to restore teeth in situ, using either a permanent tooth meant for extraction, usually for orthodontic indications or in a deciduous tooth soon to be exfoliated. The time before extraction has varied from 7 days [133], 4 to 6 weeks [134], to 5 to 7 weeks [135], or up to 18 months for exfoliated primary molars [136,137]. In general, the conclusions made from these studies do not deviate from the observations made in the laboratory experiments.…”