Cytotoxic effects of different self-adhesive resin cements: Cell viability and induction of apoptosis

PURPOSE@#. The effects of four different self-adhesive resin cement materials on cell viability and apoptosis after direct and indirect exposure were evaluated using different cell culture techniques. @*MATERIALS AND METHODS@#. Self-adhesive cements were applied to NIH/3T3 mouse fibroblasts by the extract test method, cell culture inserts, and dentin barrier test method. After exposure periods of 24 h and 72 h, the cytotoxicity of these self-adhesive materials was evaluated using the MTT assay (viability) and the Annexin-V-FITC/PI staining (apoptosis). @*RESULTS@#.The lowest cell viability was found in cells exposed to BeautiCem SA for 24 h in the extract test method. Cell viability was reduced to 70.6% compared to negative controls. After the 72 h exposure period, viability rate of cell cultures exposed to BeautiCem SA decreased more than 2- fold (29.5%) while cells exposed to RelyX U200 showed the highest viability rate of 71.4%. In the dentin barrier test method, BeautiCem SA induced the highest number of cells in apoptosis after a 24 h exposure (4.1%). Panavia SA Cement Plus was the material that caused the lowest number of cells in apoptosis (1.5%). @*CONCLUSION@#. The used self-adhesive cements have showed different cytotoxic effects based on the evaluation method. As exposure time increased, the materials showed more cytotoxic and apoptotic effects. BeautiCem SA caused significantly more severe cytotoxic and apoptotic effects than other cements tested. Moreover, cements other than BeautiCem SA have caused necrotic cell death rather than apoptotic cell death.

The effect of sandblasting duration on the bond durability of dual-cure adhesive cement to CAD/CAM resin restoratives

PURPOSE: To evaluate the effect of prolonged sandblasting on the bond durability of dual-cure adhesive resin cement to computer-aided design and computer-aided manufacturing (CAD/CAM) restoratives. MATERIALS AND METHODS: Nano-ceramic LAVA Ultimate and hybrid-ceramic VITA Enamic CAD/CAM blocks were used for this study. Each CAD/CAM block was sectioned into slabs of 4-mm thickness for the microtensile test (µTBS) test and 2-mm thickness for the surface roughness test. Three groups were created according to the sandblasting protocols; group 1: specimens were sandblasted for 15 seconds, group 2: specimens were sandblasted for 30 seconds, and group 3: specimens were sandblasted for 60 seconds. After sandblasting, all specimens were luted using RelyX Ultimate Clicker. Half the specimens were subjected to µTBS tests at 24 hours, and the other half were subjected to tests after 5000 thermocycles. Additionally, a total of 96 CAD/CAM block sections were prepared for surface roughness tests and scanning electron microscopy (SEM) evaluations. The Mann-Whitney U test, Kruskal-Wallis one-way analysis of variance, and Dunn's post hoc test were used to compare continuous variables among the groups. RESULTS: At baseline, group 1, group 2, and group 3 exhibited statistically similar µTBS results for LAVA. However, group 3 had significantly lower µTBS values than groups 1 and 2 for VITA. After 5000 thermocycles, µTBS values significantly decreased for each block (P < .05). CONCLUSION: It is important to perform controlled sandblasting because it may affect bond strength results. Sixty seconds of sandblasting disturbs the initial µTBS values and the stability of adhesion of CAD/CAM restoratives to dual-cure adhesive resin cement for VITA Enamic.

The effect of glazing and aging on the surface properties of CAD/CAM resin blocks

PURPOSE: To investigate the effect of accelerated aging on surface properties of glazed CAD/CAM resin blocks using a 2D surface profilometer and a 3D non-contact optical profilometer. MATERIALS AND METHODS: Three types of CAD/CAM resin restorative materials, LAVA Ultimate (3M ESPE, St Paul, MN, USA), VITA Enamic (Vita Zahnfabrik H. Rauter, Bad Säckingen, Germany), and Cerasmart (GC Corparation, Tokyo, Japan) were used for this study. CAD/CAM blocks were cut in 3-mm thickness slabs and divided into three groups; Group 1: control group (specimens polished with 600 grit SCI paper); Group 2: specimens sandblasted, silanized, and glazed with Optiglaze Color (GC); Group 3: glazed specimens subjected to 5000 thermocycles (n=15). The surface roughness (Ra and Rz) was evaluated using a profilometer and a 3D scanning instrument. Data were analyzed using two-way ANOVA and Tukey's post-hoc test (P .05). For VITA and Cerasmart, the specimens in Group 1 exhibited significantly higher Ra values than Group 2 (P .05). CONCLUSION: Glaze material Optiglaze Color makes CAD/CAM resin surfaces smooth and glazed CAD/CAM surfaces seem resistant to deterioration under 5000 thermocycles.

Microhybrid versus nanofill composite in combination with a three step etch and rinse adhesive in occlusal cavities: five year results

OBJECTIVES: The aim of the study was to evaluate the 5-year clinical performance of occlusal carious restorations using nanofill and microhybrid composites, in combination with 3-step etch-and-rinse adhesives, in patients who were going to commence orthodontic treatment. MATERIALS AND METHODS: A total of 118 restorations for occlusal caries were conducted prior to orthodontic treatment. Occlusal restorations were performed both with Filtek Supreme XT (3M ESPE) and Filtek Z250 (3M ESPE) before beginning orthodontic treatment with fixed orthodontic bands. Restorations were clinically evaluated at baseline and at 1, 2, 3, 4, and 5-year recalls. RESULTS: None of the microhybrid (Filtek Z250) and nanofill (Filtek Supreme XT) composite restorations was clinically unacceptable with respect to color match, marginal discoloration, wear or loss of anatomical form, recurrent caries, marginal adaptation, or surface texture. A 100% success rate was recorded for both composite materials. There were no statistically significant differences in any of the clinical evaluation criteria between Filtek Z250 and Filtek Supreme XT restorations for each evaluation period. CONCLUSIONS: The composite restorations showed promising clinical results relating to color matching, marginal discoloration, wear or loss of anatomical form, recurrent caries, marginal adaptation, and surface texture at the end of the 5-year evaluation period.

The effect of different drinks on the color stability of different restorative materials after one month

OBJECTIVES: The aim of this study was to evaluate the effect of three different drinks on the color parameters of four different restorative materials. MATERIALS AND METHODS: Three different composites (Filtek Ultimate Universal Restorative, Filtek Ultimate Flowable, and Filtek Silorane, 3M ESPE) and a polyacid-modified composite resin material (Dyract XP, Dentsply DeTrey GmbH) were evaluated. Eighty-four disc-shaped specimens of 8 mm in diameter and 2 mm in thickness were prepared (n = 21 each). Color coordinates (L*a*b*, DeltaL*, Deltaa*, Deltab*, and DeltaE*) were measured using a VITA Easyshade Compact (VITA Zahnfabrik) after 24 hr of storage (baseline) and after 30 day of storage in three different beverages of black tea, Coca cola, or water (control) (n = 7). In each beverage, the specimens were stored three times a day, one hr each, for 30 day. The color changes (DeltaE) were calculated and were analyzed by Kruskal-Wallis and Dunn multiple comparison test. RESULTS: The color difference (DeltaE*) of the resin materials ranged between 1.31 and 15.28 after 30 day of immersion in the staining solutions. Dyract XP in Coca cola (15.28 +/- 2.61) and black tea (12.22 +/- 2.73) showed the highest mean DeltaE* value after 30 day, followed by Filtek Ultimate Universal Restorative (5.99 +/- 1.25) and Filtek Ultimate Flowable (4.71 +/- 1.40) in black tea (p < 0.05). CONCLUSIONS: The compomers displayed unacceptable color changes at the end of 30 day in all beverages. Among resin composites, the silorane based composite exhibited relatively good color stability than the others. Filtek Ultimate Universal Restorative and Filtek Flowable showed similar color changes in all beverages.