IADR Abstract Archives
Non-destructive Evaluation of Microgaps Between Dentin and Ceramic Materials
Objectives: The aim of this in vitro study was to assess the interfacial adaptation of lithium disilicate and zirconia to dentin using Optical Coherence Tomography (OCT) and Confocal Laser Scanning Microscopy (CLSM). The null hypothesis is that there is no difference in adhesive interfacial adaptation using different types of cement or restorative materials.
Methods: 48 intact molars extracted for periodontal reasons were selected and cut in order to obtain dentin discs of 1 mm thickness and they were randomly divided into 3 groups (n=16) according to the material used for luting: G1) 45°C heated composite (Clearfil Majestic ES-2), G2) nanofilled composite (Clearfil Majestic ES-2) at room temperature, G3) dual-curing resin adhesive cement (Bifix QM). Each group was further divided into two subgroups considering the ceramic material: zirconia (Katana SMTL) and lithium disilicate (E-Max). Adhesive interface was assessed with Optical Coherence Tomography (Spectralis, Heidelberg Engineering, Germany) and images were analyzed with the software ImageJ to assess the percentage of marginal gap. The presence and the dimension of the gaps at the adhesive interfaces, after OCT evaluation, were also confirmed by CLSM. Collected data were statistically analyzed with ANOVA test and Tukey post-hoc test, significance was set for p<0.05.
Results: Heated composite and dual-curing cement showed a significantly lower presence of internal gaps and voids when employed to lute lithium disilicate and zirconia (p=0,001). Moreover, the adhesive interface quality was not affected by the ceramic material chosen. Heated composite and dual-curing resin adhesive cements showed the same behavior in terms of gap percentage.
Conclusions: Within the limitations of an in vitro study we can affirm that less viscous adhesive cements better adapt to dentinal surface and subsequently produced less risk of bacterial invasion, secondary caries and fracture of lithium disilicate and zirconia restorations
Methods: 48 intact molars extracted for periodontal reasons were selected and cut in order to obtain dentin discs of 1 mm thickness and they were randomly divided into 3 groups (n=16) according to the material used for luting: G1) 45°C heated composite (Clearfil Majestic ES-2), G2) nanofilled composite (Clearfil Majestic ES-2) at room temperature, G3) dual-curing resin adhesive cement (Bifix QM). Each group was further divided into two subgroups considering the ceramic material: zirconia (Katana SMTL) and lithium disilicate (E-Max). Adhesive interface was assessed with Optical Coherence Tomography (Spectralis, Heidelberg Engineering, Germany) and images were analyzed with the software ImageJ to assess the percentage of marginal gap. The presence and the dimension of the gaps at the adhesive interfaces, after OCT evaluation, were also confirmed by CLSM. Collected data were statistically analyzed with ANOVA test and Tukey post-hoc test, significance was set for p<0.05.
Results: Heated composite and dual-curing cement showed a significantly lower presence of internal gaps and voids when employed to lute lithium disilicate and zirconia (p=0,001). Moreover, the adhesive interface quality was not affected by the ceramic material chosen. Heated composite and dual-curing resin adhesive cements showed the same behavior in terms of gap percentage.
Conclusions: Within the limitations of an in vitro study we can affirm that less viscous adhesive cements better adapt to dentinal surface and subsequently produced less risk of bacterial invasion, secondary caries and fracture of lithium disilicate and zirconia restorations
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