Adaptação marginal de restaurações indiretas em composito fixadas com resinas de ativação dupla

AUTOR(ES)
DATA DE PUBLICAÇÃO

2000

RESUMO

The purpose of this study was to evaluate the marginal adaptation of composite indirect restorations bonding with dual curing resin cements. Restorations were made with Targis (Ivoclar/Nivadent), a composite resin for indirect technique. The resins for bonding have in common chemical and light curing activation. Panavia-F (Kuraray) utilizes a self-etching primer named ED­ Primer (Kuraray) prior to the fixation, and Rely X (3M) that works with the adhesive Single Bond (3M) which requires phosporic acid etching technique. Forty extracted human molars were grinded on wet sandpaper to remove adequate amount of enamel in the occlusal to obtain a flat surface in dentin. Inlay preparations limited to dentin were done with diamond and finishing burs. Stone casts were obtained from impressions made with addition silicone. Indirect restorations were made in those casts then was divided in two groups and bonded to each prepared tooth following manufacturer s instructions, being 20 with Panavia-F and 20 with Rely X. After bonding procedures each restoration was polished with a sequence of wet sandpaper (400 and 600, 1000 grain) followed by diamonds pastes (6?m , 3?m, 1?m and 1/4 ?m). Specimens were cleaned with in ultrasonic with distilled water between each polishing step. The specimens were subjected to thermocycling between 5°e and 55°C, for 1200 cycles. A solution of red acid and propylene-glycol was dropped on each specimen for 10 seconds and after that washed and dried with tissue paper. Staining penetration was captioned under stereoscopic lens; the image of the restoration was then transferred to a computer with a measurement program to determine the extension of stain penetration. Staining penetration values were obtained by staining margin length by total cavity length, then multiplied by 100. The results were submitted to non-parametric statistical analysis with the Mann­ Whitney Test. Half of the specimens was sectioned, polished with a sequence of diamond pastes and covered with Au-Pd for SEM evaluation of internal and externaI margins. Results showed that Panavia F had mean value of 22,17% and Rely X 36,78% of marginal staining, however it was not statistically different. SEM analysis showed no gaps on the external and internal interface, between dentin and restoration for both resin cements. However, were observed air bubbles inside the resin cements and porosities in small areas in occlusal surface, independent of bonding material

ASSUNTO(S)

protese dentaria resinas dentarias cimentos dentarios

ACESSO AO ARTIGO

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