Shear bond strength and marginal adaptation of glass ionomers to chemomechanically treated human permanent dentine: a scanning electron microscopic [SEM] evaluation

ABSTRACT

The search for a dental restorative material which adheres directly to enamel and dentaic was the need of clinical dentistry. The performance of restorative conventional and rein-modified glass ionomer cements to chemiomechanically treated human permanent dentive will be of help for clionical dentistry. To determine the effect of a chemomechanical caries removal [CMCR] gel Carisolv TM on shear bond strength [SBS] and marginal adaptation of conventional glass ionomer cement [OGIC] and resin-modified glass ionomer cement [RMGIC] bonded to human permanent dentine. One conventional glass ionomer cement [Fuji IX, GC Co. Tokyo Japan] and one resin-modified glass ionomer cement [Fuji II, GC Co. Tokyo Japan] was used. Sixty four teeth were sectioned occlusally; exposed coronal dentine was polished wit silicon papers. Teeth in the control groups [C] wee directly bonded to respective glass ionomer cements [GICs]. For test groups [T] the polished dentine surface was pretreated with Carisolv TM [Singlemix Uncolored Gel, Medi Team, Sweden] prior to bonding. Bonded specimens were stored for 24 hours stressed to failure in the shear mode. Failure modes were identified with a Stereoscopic Microscope. Each type of failure mode was further examined under a Scanning Electron Microscope [SEM]. To evaluate the adaptation of GICs to underlying dentine surfaces, one additional specimen was prepared and sectioned through the centre. Sectioned specimens were analyzed using backscattered Electron imaging mode. SBS of Fuji IX, test group [4.9 +/- 0.82 Mpa] significantly higher [P = 0.001] than it's control group [3.98 +/- 0.67 Mpa]. Whereas, no significant difference [P = 0.160] was observed in SBS of Fuji II test group [13.52 +/- 1.88 Mpa] and control groups [12.23 +/- 2.89 Mpa]. Predominant failure mode observed was cohesive failure within the cement. SEM examination showed that both Fuji IX and Fuji II specimens had smooth and even cement-dentine interface. Carisolv TM pretreatment did not adversely affect the bond strength of conventional and resin modified glass ionomer cements to dentine