The aim of the study was to investigate the effect of xylitol, from some oral hygiene products and chewing gums, on salivary parameters variation in patients with carious disease. The study was performed on 30 patients with a medium level of carious disease, randomly divided in two groups as follows: group 1 (study group), using xylitol-based products for 30 days, and group 2 (control group), using products without xylitol. The way of administration, dose, and frequency of use were as follows: toothpaste (normal daily brushing, 3 times daily); mouthwashing (5 ml, twice daily); chewing gums (two tablets, 5 times daily), for 30 days. The assessment targeted the salivary parameters as follow: saliva microcrystallisation index (IMK), resting salivary flow rate (RSF), stimulated salivary flow rate(SSF). The results of our study confirm the improvement of salivary parameters due to the use of xylitol-based products, by the positive influence on the remineralisation capacity of saliva. The assessment method of saliva IMK represents a noninvasive, simple, informational indicator for the assessment of the remineralisation capacity of saliva.

The aim of this study was to assess the quality of the interface between dental root cement and some restorative materials used in the open sandwich technique. Standardised cavities were prepared on the buccal and oral surfaces of 30 human molars with the gingival margin situated in root cement. The teeth were randomly divided in 3 groups. Different materials combinations were used in buccal and oral cavities. In the control group, the cavities were filled only with composite resins (Filtek Z250-3M ESPE and Zmack Comp-Zermack). In the test groups the cavities were restored using an open sandwich technique as follows: in group 1 Filtek Z250 in combination with Dyract, respectively Ketac Molar Easymix; in group 2 Zmack Comp in combination with Dyract, respectively Ketac Molar. The teeth were stored in 1% methylene blue solution, for 24 hours. The samples were longitudinally sectioned through the centre of restorations and the degree of dye penetration as well as the morphology of the interface between the root cement and the restorative material were evaluated by optical microscopy and SEM. The results showed less microleakage and and adhesive failures in open sandwich restorations with Zmack Comp and Dyract combination.

The aim of this study was to evaluate and to compare the compression behavior under identical mechanical tests, of three different composite resins, by determining Young�s modulus for compression, ultimate compressive strength and ultimate compressive strain. The studied materials were: Filtek Z250 Universal Restorative, Filtek Z550 and Filtek Bulk Fill Posterior Restorative (3M ESPE, St. Paul, MN, USA). Fifteen cylindrical samples, having 6 mm in height and 5 mm in diameter, were made from each material, using plastic molds. The samples were subjected to quantitative analysis of the compression behavior after mechanical tests. The fractured fragments of the samples were subjected to qualitative surface evaluation by scanning electron microscopy. Results were statistically analyzed using one-way analysis of variance (ANOVA) with Tukey�s post hoc test. Filtek Z250 had the lowest value of Young�s modulus for compression and the results were statistically significant (p[0.05) when compared to Filtek Bulk Fill Posterior Restorative and Filtek Z550. There were no statistically significant differences between all three materials regarding ultimate compressive strength (p]0.05). The lowest value for ultimate compressive strain was recorded for Filtek Bulk Fill.

The load-bearing capacity and fracture pattern of direct inlay-retained FRC FDPs with two different cross-sectional designs of the ponticwere tested. The aim of the study was to evaluate a new fibre disposition. Two types of composites, Filtek Bulk Fill Posterior Restorative and Filtek Z250 (3M/ESPE, St. Paul, MN, USA), and one braided polyethylene fibre, Construct (Kerr, USA) were used. The results of the study suggested that the new tested disposition of the fibres prevented in some extend the delamination of the composite on buccal and facial sides of the pontic and increased the load-bearing capacity of the bridges.

The aim of the study was to compare the marginal adaptation of three different resin-based materials used for direct restoration: hybrid composite resin (Gaenial Posterio, GC Corporation), a compomer (Dyract eXtra, Dentsply Sirona), and a giomer (Beautifil II, Shofu Dental) applied at room temperature or after preheated at preheating 50 and 60oC. Class II cavities were prepared on proximal surfaces of extracted teeth and randomly divided in 3 groups according to the material used for restoration. In each group five cavities were restored using the materials at room temperature (subgroup 1), five cavities were restored using preheated materials at 50şC (subgroup 2), and five cavities were restored using preheated materials at 60şC (subgroup 3). The teeth were stored in distilled water for 14 days and then were immersed in 2% methylene blue buffered dye solution (pH = 7) for 4 hours. The teeth were transversally cut and the sections were examined using optical microscope (Carl-Zeiss AXIO Imager A1m) at 50x magnification and the dye penetration was evaluated according to 4 scores. Decreased microleakage and fewer gap formation were recorded for all filling materials after they have been heated at 50 or 60oC. Pre-warming of resin-based materials improves the adaptation of these materials to tooth structures.

The aim of this in vitro study was to to evaluate the impact of finishing procedures on the enamel adjacent to composite restorations and to assess if the resistance of the enamel-resin junction to leakage is affected by the use of these instruments. The surfaces of enamel at the joint with composite were observed by scanning electron microscopy, then the microleakages at the enamel margin was assessed using an optical microscope. Finishing with extra-/ ultra-fine carbide burs and extra-fine diamond burs produced a superficial abrasion to the adjacent enamel and did not seem to have a significant influence on the sealing ability of composite resin.

Introduction: The aims of the study were to investigate the enamel and dentin marginal seal of a universal adhesive system applied with etch and rinse and selfetch strategy and to evaluate the enamel and dentin marginal microleakage in case of saliva contamination on different steps of the adhesive application by dye penetration assessment. Methodology: Thirty class V cavities were prepared on the buccal face (group I-etch and rinse application of universal adhesive system) and the lingual face (group II-self-etch application of universal adhesive system) of molars and bicuspids. In each group 3 subgroups were created according to the moment of the saliva contamination: subgroup 1-no contamination, subgroup 2-contamination before light curing the adhesive, subgroup 3-contamination after light curing the adhesive. The dye penetration at the adhesive interface was evaluated according to a 4-score scale. Results: In both groups increased enamel and dentin microleakage was recorded in subgroups 2 and 3 when comparing to subgroup 1. In group I saliva contamination before and after light curing the adhesive resin led to similar mean value of dentin microleakage. Increased values of microleakage were recorded in group II when comparing to group I in the subgroups where contamination with saliva was done before light curing the adhesive resin. Conclusions: Saliva contamination of the adhesive system after light curing increased enamel microleakage only when the adhesive system was applied with etch and rinse strategy. Increased dentin microleakage after contamination was recorded with both strategies of universal adhesive system application.

The aim of this study was to compare Rockwell hardness (HRC) and modulus of elasticity (Young modulus) to different restorative materials. Three commercial composite resins: Filtek Z250 (3M ESPE Co.), Zmack Comp (Zermack SpA, Italy), Kalore (GC Corporation, Japan) and one compomer: Dyract eXtra (Dentsply De Trey Gmbh, Germany) were used. Six samples of each material were obtained by placing them in plastic rings having 5 mm inner diameter and 6 mm high. All composite samples were cured for 40 s using a lamp LEDidition - Ivoclaire Vivadent clinical, Austria. The samples were finished and polished and then stored in distilled water, at room temperature for 48 hours. Rockwell Hardness (HRC) measurements were realized using the UMT-2 Tribometer (CETR). The hardness was automatically calculated from the slope of unloading curve and expressed in GPa and transformed in HRC values (kgf/mm2). Six indentations were performed on diametral direction and mean values were calculated for all tested samples. The device also measured the modulus of elasticity for each sample. Data were analyzed by ANOVA and Mann-Whitney test (significance level of p [ 0.05). The mean HRC values were the following: Filtek Z250 ] Zmack Comp ] Dyract eXtra ] Kalore (82.98 ] 70.10 ] 53.27 ] 37.72 kg/mm2). Regarding Young modulus, the rank from highest to lowest as follows: FiltekZ250 ] Zmack Comp ] Dyract eXtra ] Kalore (16.24 ] 14.05 ] 12.41 ] 7.86). The microhydrid composite resins have a significantly higher hardness than nano-hybrid composites or compomers.