MATERIALS AND METHODS: Sixty maxillary central incisors were divided into Group I, II, and III with 20 samples each based on luting cement used. They were OF, self-adhesive (SA) cement, and total etch (TE) cement. These groups were subdivided into "a" and "b" of ten each based on the type of veneering materials used. Veneer discs were fabricated using Ormocer restorative (O) and pressable ceramic (C). Specimens were thermocycled and loaded under universal testing machine for SBS. The statistical analysis was done using one-way ANOVA post hoc Tukey honest significant difference method.
RESULTS: A significant difference was observed between the Groups I and II (P < 0.05). The highest mean bond strength when using ormocer veneer was obtained with the Group Ia (19.11 ± 1.92 Mpa) and lowest by Group IIa (8.1 ± 1.04 Mpa), whereas the highest mean bond strength while using ceramic veneer was of similar range for Group Ib (18.04 ± 4.08 Mpa) and Group IIIb (18.07 ± 1.40 Mpa). SEM analysis revealed OF and TE presented mixed type of failure when compared with SA where failure mode was totally adhesive.
CONCLUSION: OF was found equally efficient like TE. Bond strength of ormocer as a veneer was not inferior to ceramic making it one of the promising additions in the field of dentistry.
MATERIALS AND METHODS: Three categories of materials, namely, test group 1 (cGIC or type IX GIC), test group 2 (HA-GIC or hydroxyapatite-added GIC), and positive control (glass cover slips) were incubated with human periodontal ligament fibroblasts. The samples were viewed under scanning electron microscope to study the morphological characteristics of fibroblasts. Additionally, elemental analysis was performed to differentiate between the two test groups based on surface chemical composition.
RESULTS: Test group 1 (cGIC) exhibited cells with curled up morphology, indicative of poor attachment to the substrate. Test group 2 (Ha-GIC) exhibited cells with flattened morphology and numerous cellular extensions such as lamellipodia and blebs, indicative of good attachment to the substrate. The test group 2 (Ha-GIC) demonstrated higher surface elemental percentages of calcium and phosphorus.
CONCLUSION: Within the limitations of this study, it may be concluded that hydroxyapatite-added GIC is more biocompatible than conventional GIC (type IX), probably attributed to high elemental percentages of calcium and phosphorus.
CLINICAL SIGNIFICANCE: The search for an ideal cervical restorative dental material has been ever elusive. Hydroxyapatite-added GIC is a simple and economical dental material to fabricate from basic conventional GIC. The results from this study strengthen its candidature for cervical and root surface restorations which may later require soft tissue augmentation. The possibility of connective tissue adhesion to this material is an exciting prospect in the field of periorestorative dentistry.
AIM: To evaluate the shear bond strength of Zinc phosphate cement Elite, glass ionomer cement Fuji I, resin-modified glass ionomer cement Fuji Plus and resin luting cement Panavia-F to Turkom-Cera all-ceramic material.
MATERIALS AND METHODS: Turkom-Cera was used to form discs 10mm in diameter and 3 mm in thickness (n = 40). The ceramic discs were wet ground, air - particle abraded with 50 - μm aluminium oxide particles and randomly divided into four groups (n = 10). The luting cement was bonded to Turkom-Cera discs as per manufacturer instructions. The shear bond strengths were determined using the universal testing machine at a crosshead speed of 0.5 mm/min. The data were analysed using the tests One Way ANOVA, the nonparametric Kruskal - Wallis test and Mann - Whitney Post hoc test.
RESULTS: The shear bond strength of the Elite, Fuji I, Fuji Plus and Panavia F groups were: 0.92 ± 0.42, 2.04 ± 0.78, 4.37 ± 1.18, and 16.42 ± 3.38 MPa, respectively. There was the statistically significant difference between the four luting cement tested (p < 0.05).
CONCLUSION: the phosphate-containing resin cement Panavia-F exhibited shear bond strength value significantly higher than all materials tested.
MATERIALS AND METHODS: An experimental GIC (ex-GIC) was prepared by mixing CHX-D powder with the powder of type II GIC to obtain 1% (w/w) concentration of CHX-D in the GIC. Antibacterial activity of this ex-GIC was tested against L. casei and A. viscosus using the agar diffusion method. The ex-GIC specimens were tested in their unset and set forms for each bacterium. For the unset group, specimens were placed in each agar plate immediately after manipulation and for the set group, specimens were placed in each agar plate, 1 hour after manipulation. The inhibition zones on the agar plate were recorded in millimeters immediately on placement of the specimen in the agar plate and after 48 hours. The reading was recorded and statistically analyzed for significant difference.
RESULTS: Mann-Whitney U test showed statistically significant difference in the inhibition zones produced by ex-GIC against L. casei and A. viscosus when both were compared in unset (p-value = 0.002) and set (p-value = 0.031) groups. For both the groups, the zone of inhibition against L. casei was greater. Though the unset group recorded wider zone of inhibition, the difference was not significant when compared with the respective set group. This was true for both the bacterial groups.
CONCLUSION: The 1% CHX-D-modified type II GIC showed antibacterial property against L. casei and A. viscosus and significantly higher activity against L. casei.
CLINICAL SIGNIFICANCE: Addition of 1% CHX-D to type II GIC showed evidence of antibacterial activity against organisms found in deep carious lesion and therefore may exhibit superior antimicrobial efficiency when used as an intermediate therapeutic restoration in deep cavities.