Microleakage in conservative cavities varying the preparation method and surface treatment

Abstract

ObjectiveTo assess microleakage in conservative class V cavities prepared with aluminum-oxide air abrasion or turbine and restored with self-etching or etch-and-rinse adhesive systems.Material and MethodsForty premolars were randomly assigned to 4 groups (I and II: air abrasion; III and IV: turbine) and class V cavities were prepared on the buccal surfaces. Conditioning approaches were: groups I/III - 37% phosphoric acid; groups II/IV -self-priming etchant (Tyrian-SPe). Cavities were restored with One Step Plus/Filtek Z250. After finishing, specimens were thermocycled, immersed in 50% silver nitrate, and serially sectioned. Microleakage at the occlusal and cervical interfaces was measured in mm and calculated by a software. Data were subjected to ANOVA and Tukey’s test (α=0.05).ResultsForty premolars were randomly assigned to 4 groups (I and II: air abrasion; III and IV: turbine) and class V cavities were prepared on the buccal surfaces. Conditioning approaches were: groups I/III - 37% phosphoric acid; groups II/IV -self-priming etchant (Tyrian-SPe). Cavities were restored with One Step Plus/Filtek Z250. After finishing, specimens were thermocycled, immersed in 50% silver nitrate, and serially sectioned. Microleakage at the occlusal and cervical interfaces was measured in mm and calculated by a software. Data were subjected to ANOVA and Tukey’s test (α=0.05).ConclusionMarginal seal of cavities prepared with aluminum-oxide air abrasion was different from that of conventionally prepared cavities, and the etch-and-rinse system promoted higher marginal seal at both enamel and dentin margins.

Polymerization stress – Is it clinically meaningful?

“…Numerous studies show that even when attempting to bond the material to a cavity preparation, the marginal seal is typically compromised, resulting in marginal gaps, stains, or leakage [49,50]. This deficiency remains true even with current "improved" adhesive systems [51][52][53]. In fact most in vitro leakage studies have shown that dental composites do not provide a perfect seal to either enamel or dentin, independent of bonding or placement method [54].…”

Evaluation of microleakage in class V composite restorations using dye penetration and micro-CT

“…bacteria, fluids, molecules, or ions between a cavity wall and the restoration [4]. Different approaches have been introduced in an attempt to decrease microleakage during the adhesiverestorative procedures such as the application of different curing strategies, the reduction of polymerization shrinkage by the incremental layering technique, the use of flowable composites, the surface treatment, and the development of new adhesive systems [5][6][7][8][9]. However, these measures have not been able to prevent microleakage completely.…”

Effect of desensitizers on the microleakage of previously restored Class V resin composite restorations

“…[46] This finding was in agreement with those of previous similar studies. [13,14,39,47,48] At the gingival margins, the bonding groups presented the lowest microleakage scores. However, none of the materials tested were completely resistant to dye penetration (leakage) at the gingival margins.…”