Resin penetration through submicrometer hiatus structures: A SEM and CLSM study

Abstract

The purpose of this study was to confirm the existence of submicrometer hiatus structures and to examine the degree of resin penetration through these formations. Dentin disks 2.0 mm in thickness were sectioned from 48 human molars with the use of a microtome saw. Three different fifth-generation (total-etch, combined primer/resin) dentin adhesive systems were used to bond a light-cured, resin-based composite to the dentin disks (n = 16 each group). Bonded disks from the three groups were then sectioned. Half of each group was examined with the use of a scanning electron microscope (SEM) (n = 8), and the other half with the use of a confocal laser scanning microscope (CLSM) (n = 8). The frequency of submicrometer hiatus formation was recorded and documented with associated imaging techniques. Resin penetration within submicrometer hiati were observed in 41.7% (10/24) of SEM specimens and 83.3% (20/24) of CLSM specimens. The location and size of these structures were found to be quite uniform. Submicrometer hiati approximated 200 microm in each of the three dentin bonding systems examined. Resin penetration through submicrometer hiati does not appear to be an artifact of desiccation. These structures were clearly identified within the hybrid layer of each dentin adhesive system used in this study.

Confocal laser scanning microscopy for the study of the morphological changes of the postextraction sites

“…CLSM has been used in dentistry for the characterisation of the composite–dentin interface in dental restorations (Bitter et al,2009; Ding et al,2010; Pioch et al,2004), for the study of the performance of the materials used in dental restorations (Belli et al,2009; Etman et al,2009) and in the assessment of the cariostatic effect of restorative materials or fluoride compounds (Büyükyilmaz et al,1997; Czochrowska et al,1998; De Carvalho et al,2009; González‐Cabezas et al,1998; Ogaard et al,1996; Okuda et al,2003; Umino et al,2005). CLSM has also been used in the examination of the alveolar bone (Baschong et al,2001; Favia et al,2009; Iyama et al,1997; Nishikawa et al,2006; Pilolli et al,2008; Suzuki et al,1997; Traini et al,2007) and the dental hard tissues (Crincoli et al,2007; Girija et al,2003; Goracci et al,1999; Grötz et al,1998; Kabasawa et al,1995; Kagayama et al,1997; Love and Chandler1996; Lucchese et al,2008; Radlanski et al,2001; Saini et al,2007; Sakakura et al,1998; Scivetti et al,2007; Sønju et al,1997), in microbiological evaluation (Dige et al,2007; Takenaka et al,2001; Zaura‐Arite et al,2001) and in the study of the peridental soft tissues (Chantawiboonchai et al,1998).…”