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Background: The aim of this in vitro study was to reveal in a time-dependent manner the effect of received irradiance produced by different light-emitting-diode (LED) lamps on the surface microhardness of composite material used in the restoration of posterior teeth. Methods and Results: A single nanofilled resin composite, Estelite Posterior (Toquyama Dental Corp, Japan) shade PA3, was used to perform this in vitro study. Ninety cylindrical filling samples were made with the help of plastic ring molds and plates to obtain flat surfaces. The mean diameter and height of prepared specimens were 5.5±0.05mm and 2.5±0.1mm, respectively. For the polymerization of the composite, two different types of light-curing units (LCU) were selected for this study: Valo X (Ultradent Products, Inc., USA) operated in a “standard” mode, and Bluephase 20i (Ivoclar Vivadent, Liechtenstein) ran in a “high” mode. Photoactivation was done with the light tips fixed parallel to the surface of the filling material and above it at a distance level of 1 mm, 4 mm, and 8 mm. The radiant power (mW) of each LCU was registered in a PL-MW2000 Optical power meter (Beijing Perfectlight Technology Co., Ltd., China). A total of 18 groups, with five filling samples in each, were formed and processed. Upon the completion of light treatment, by the ISO-4049 protocol, each specimen was immersed in water and stored at 37°C for 24 hours in a lightproof container. After this period, samples were washed and tested for the hardness of top surfaces using a “ПMT-3” Vickers hardness tester. The means of light intensities of two LCUs in the study were significantly different at 4 mm and 8 mm tip distances in 1.26 and 2 times, respectively. Analysis of hardness values did not reveal significant differences in the light-curing efficacy of two LED lamps. The differences in VHN values were obvious among the 10- and 40-second time exposure groups when the photoactivation was carried out at an 8mm tip distance. Conclusion: The effective polymerization of composite restorations with poor accessibility is still a matter of time, not the power of LCU.

The present review was intended to provide several important biological insights into the practice of implant dentistry. Despite many benefits, it’s clear that a dental implant does not share the features of a dentoperiodontal unit, and alveolar bone tolerates an implant, as far as its physiology goes, within the range of adequate response to direct masticatory load. The importance of a gingival tight seal around the transmucosal part of an implant cannot be overestimated from both biological and esthetic aspects. Considering the multifactorial nature of bone augmentation, the successful outcome of this type of surgery is still a matter of chance.

Background: This study aimed to reveal the effect of preheating on the surface microhardness and shear strength of composite materials used in the restoration of posterior teeth. Methods and Results: There were 3 composite materials under the study: Estelite Posterior, Harmonize and Filtek Z550. To make static and dynamic tests of them, 120 filling samples were prepared. Of those, 60 samples were for surface hardness measurements and 60 samples were used to evaluate the shear strength of composite materials. We formed 12 study groups with 10 filling samples in each. Samples made off Estelite Posterior, Harmonize™, and Filtek™ were designated with E, H, and F capital letters, respectively; the "VH" abbreviation indicated static Vickers hardness testing and "SS" was assigned for dynamic shear testing; mark (°) was used when preheating was applied. Filling samples were made of heated (up to 60°C) and room-temperature (23-25°C) composite materials. The filling samples of EVH, EºVH, HVH, HºVH, FVH, and FºVH groups were subjected to a surface microhardness test. The samples of ESS, EºSS, HSS, HºSS, FSS, and FºSS groups were subjected to shear-strength assessment of materials. The surface microhardness of filling samples was measured using a ПMT-3 Vickers hardness tester and the Vickers hardness number (VHN) was calculated. Dynamic tests were carried out using an UltraTester machine (Ultradent, Inc., USA) and shear test method until the shear-strength (SS) filling sample had completely failed. After analysis of the obtained results, it was found that preheating had enhanced the surface hardness and mechanical strength of the composite materials used in the study. However, the positive influence of preheating was significant only in the EVH-EºVH, ESS-EºSS, HSS-HºSS, and FSS-FºSS groups in 1.21, 1.09, 1.33, and 1.16 times, respectively. In the HVH-HºVH and FVH-FºVH groups, the identified differences were not of significance despite the improvement in mean values at 1.08 and 1.1 times. Conclusion: Preheating of light-curing resin-based composites is not equally effective for static and dynamic mechanical properties of materials for dental restoration. Preliminary laboratory tests could have helped before their clinical use.

Background: Recently, synthetic materials based on bioactive glasses have been in special demand in dental implantology, which, according to the mechanism of their action, are not only osteo-conductors, but also osteo-inductors. Of even greater interest is the fact that the biological degradation of these materials causes alkalization of the area and inhibits the growth of many pathogens. Considering the unique properties of this group of osteoplastic fillers and the problems associated with healing after guided bone regeneration, this study aimed to compare the effectiveness of using bioactive glasses S53P4 and 45S5 when performing vertical bone augmentation in an experiment applying a rabbit tibia model. Methods and Results: Six adult outbred rabbits aged from 1.5 to 2 years and weighing from 2.5 kg to 3.2 kg were used in the study. A titanium mesh was used to perform a true vertical guided bone regeneration technique. In each animal, two titanium tents were placed: one on the left tibia and one on the right tibia. On the left limb, empty spaces were filled with bioactive synthetic bone filler NovaBone® Morsels (USA); on the right limb, we used a mixture of bioactive glass Bonalive® granules CMF (Finland) and mineralized bone MedPark Bone-D XB (Bovine Xenograft, South Korea) in a ratio of 1:1. The quantity and quality of regenerated tissues were assessed after 8-10 weeks. The NovaBone application has allowed a gain of 2.6±2.67 mm in extra-skeletal hard tissue growth. No signs of guided bone regeneration were observed in all cases of application of an osteoplastic mixture of Bonalive and Bone-D XB granules. Conclusion: Within the limits of this study, it was found that the use of a mixture of bioactive glass Bonalive (S53P4) with bovine hydroxyapatite in a 1:1 ratio was not effective in vertically guided bone regeneration, but the application of NovaBone (45S5) could promote a new bone formation.

Background: The aim of this research was to study the effect of air-abrasive treatment of dentin on the chemical composition of its surface and the adhesion strength of 2 self-etching adhesive systems (AS). Methods and Results: Powders based on aluminum oxide (Al2O3) (27µm) (KaVo, Biberach, Germany), sodium bicarbonate (NaHCO3) (40µm) (AIR-FlOW Classic Comfort, EMS, Nyon, Switzerland), and erythritol (14µm) (AIR-FLOW Plus, EMS, Nyon, Switzerland) were used for the air-abrasive treatment of adhesive surfaces. Bonding steps were carried out with Single Bond Universal (SBU) (3M ESPE, USA) and Bond Force 2 (BF2) (Toquyama, Japan). The adhesion strength of composite to dentin was evaluated on 80 samples prepared in accordance with the Ultradent Shear Bond Strength test. All samples were divided into 4 groups depending on the method of dentin surface processing. In the samples of Group 1 (n=20), aluminum oxide was used for the air-abrasive treatment of dentin. In Group 2 (n=20) and Group 3 (n=20), samples were treated using powders based on sodium bicarbonate and erythritol, respectively. Group 4 (control, n=20) included tooth samples in which the dentin surface was not air-abraded after preparation with carbide burs. Then, each group was divided into 2 subgroups (Sub-A and Sub-B) depending on the type of adhesive system used. Adhesive resin was applied and polymerized in accordance with the manufacturer’s instructions. Single Bond Universal (SBU) was used for the samples of Sub-A, and Bond Force 2 (BF2) (Toquyama, Japan) was used for the samples of Sub-B. Scanning electron microscopy and determining the surface elemental composition of samples were carried out on an SEM-EVO MA 10 (Carl Zeiss) and energy dispersive X-ray spectrometer with EDS Aztec Energy Advanced X-Act (Oxford Instruments). It was concluded that air-abrasive treatment of the dentin surface does not enhance the adhesion strength of composite material when using self-etch AS. Also, it was noted that the pH level of self-etch AS is not a crucial feature in determining the strength of the filling-tooth interface. The resulting variations in the elemental composition of dentin surface after air-abrasion with various mixtures and their effect on the efficacy of the different AS require further in vitro studies.

The aim of this study was to determine the average amount of silicon ions on the surface of titanium implants after air abrasion with powders based on glycine and erythritol, and to measure the content of silicon ions in separated water-insoluble fractions of these powders. Methods and Results: The study investigated 2 air-abrasive powders, one based on glycine (Air-Flow Perio, EMS, Switzerland) and another on erythritol (Air-FlowPlus, EMS, Switzerland). These abrasives were tested for solubility in water and the content of Si+ in insoluble fractions of these powders. Also, the weight percent (wt %) of Si+ was measured on the surface of failed titanium implants after air abrasion with Air-Flow Perio (Group 1) and Air-FlowPlus (Group 2). Scanning electron microscopy and determining the elemental composition of obtained samples were carried out on an SEM-EVO MA 10 (Carl Zeiss) and energy dispersive X-ray spectrometer with EDS Aztec Energy Advanced X-Act (Oxford Instruments). It was found that air-abrasive mixtures based on glycine and erythritol are not completely soluble in water due to the presumed presence of silica in them. It was also found that air-abrasive cleaning of contaminated dental implants with an erythritol-based mixture contributed to a significant increase (P=0.000) in the Si+ content on their surfaces in comparison to implants treated with glycine-based powder.

The purpose of this study was to evaluate in vitro the efficacy of alumina, sodium bicarbonate and erythritol-based tooth air-abrasion on shear bond strength (SBS) of resin composite to dentin. Methods and Results: In order to assess the strength of the adhesive bond of the resin composite to tooth dentin, 50 tooth samples were prepared in accordance with the Ultradent Shear Bond Test method. All samples were divided into 5 groups. In Group 1 (n=10) and Group 2 (n=10), for air-abrasion of dentin surface 2 powders based on aluminum oxide with a particle size of 50μm and 27μm, respectively, were used (RONDOflex plus 360, KaVo, Biberach, Germany). In Group 3 (n=10) and Group 4 (n=10), other abrasive powders based on sodium bicarbonate (40μm) and erythritol (14μm), respectively, were used for a similar purpose (Air-Flow Classic comfort, Air-Flow Plus, EMS, Nyon, Switzerland). The control group (n=10) consisted of the remaining tooth samples in which the dentin surface, after preparation with a carbide bur, was not subjected to an air-abrasion.The one-day adhesive strength of bonded interfaces was evaluated on an UltraTester device (Ultradent Products Inc., USA) after resin bonding without aging simulation. The speed of movement of the test clamp with the installed sample was set to 1 mm/min. The maximal value of bonding failure was fixed in pounds (lb). The dentin surface ultrastructure was studied on 10 additional tooth samples, which were prepared for SEM analysis. It was found that the treatment of dentin surface with air-abrasive powders based on alumina (50 μm and 27 μm) and sodium bicarbonate (40 μm) did not improve the strength of the adhesive bond of resin composite to dentin. The strength of adhesion of the resin composite to dentin decreased significantly after air-abrasion of the tooth surface with erythritol-based powder.

Background: There are a large number of different types of bone-grafting materials that are used for the regeneration of atrophied alveolar ridges in order to make dental implantation possible. However, available surgical techniques and materials for bone augmentation do not contribute to the achievement of the desired reliable results and require a search for new solutions to an existing problem. A group of synthetic osteoplastic materials based on bioactive glass (BAG) may become a matter of choice in bone tissue regeneration because of special osteogenic properties. The aim of this study was to visually and histologically evaluate the behavior of an experimental BAG in rabbit tibia bone samples, which were collected from the animal 6 weeks after filling the bone defects. Methods and Results: The observation was carried out on one outbred rabbit whose tibia bone defects were filled with an experimental osteoplastic material based on the BAG. The chemical composition of the experimental osteoplastic material included SiO2 (41%), Na2O (21%), CaO (28.5%), P2O5 (6%), CaF2 (1.5%), MgO (1%), Al2O3 (1%). For histological analysis, H&E staining of paraffin-embedded tissues was performed according to the standard technique. Light microscopy of tissue samples was performed using a Leitz HM-LUX microscope (Germany). Six weeks after filling the bone defects, a strong bond between the augmented hard tissue and rabbit tibia was recognized. Also, a dense fusion of adjacent soft tissues with a newly formed bone without signs of chronic inflammation or graft particles in granular tissue was noted. Microscopic examination of the stained sections showed the presence of mature viable BT with a uniform distribution of osteocytes. Also, residual fragments of the degraded biomaterial surrounded by the fibers of a woven bone were revealed in several slices. Conclusion: In accordance with the results of this experiment, it can be concluded that the usage of BAG related to the system SiO2(41%)-Na2O(21%)-CaO(28.5%)-P2O5(6%)-CaF2(1.5%)-MgO(1%)-Al2O3(1%) may increase the volume of bone without application of barrier membrane. However, further research involving more animals needs to be done to estimate the scientific significance of the obtained data and to evaluate the mechanical properties of augmented bone.

Background: The aim of the present pilot study was to assess the bactericidal efficacy of a high frequency diathermy irradiation in treatment of teeth with diagnosed partial pulp necrosis. Methods and Results: The study included 83 patients aged between 22 and 54 years (mean age of 39±10 years) with irreversible pulpitis and signs of partial pulp necrosis in multi-rooted teeth (n=83). All patients were randomized in two groups in accordance with conducting therapy modes: 1) a conventional root canal treatment (Group 1, n=40); 2) a conventional treatment protocol in conjunction with a high frequency diathermy irradiation (Group 2, n=43). The postoperative sensitivity of treated teeth was assessed with the help of the Verbal Rating Scale (VRS). The quality of a root canal disinfection was evaluated by the presence of a cultural growth. The periapical index scoring system (PAI) was used for evaluation of periapical changes in every tooth after endodontic therapy. The occurrence of postoperative pain in Groups 1 and 2 demonstrated a similar reduction in toothache dynamics at all time intervals when assessments were made, and analysis of tooth radiographs in both groups of patients did not reveal a significant difference. As for the evaluation of a cultural growth, the signs of turbidity were detected in 6 samples of Group 1 and in 4 samples of Group 2. Conclusion: The possible antimicrobial efficacy of a high frequency diathermy in treatment of teeth with partial pulp necrosis was demonstrated. However, further studies should be made to confirm the results of this clinical trial.

Background: The aim of the present study was to compare the efficacy of packable and conventional composites in treatment of patients with class II caries lesions (CIICLs). Methods and Results: The clinical part of the study was conducted on patients with indications for composite restoration of at least two adjacent CIICCLs. There were 32 patients in whom 72 (36 pairs) teeth with caries pathology were treated. One tooth in every pair was randomly assigned for restoration with Filtek Z250 (Cl-Group 1, n=36) and another one with preheated Filtek-Р60 (Cl-Group 2, n=36). The mean observation time for composite restorations was 47.1±13.8 months. The modified USPHS criteria list was applied for clinical evaluation of the four following clinical parameters, which were used in the study: secondary caries, anatomy form, occlusal contact, and surface texture. The experimental study was conducted on 40 filling samples, which were made of conventional Filtek Z250 (Exp-Group 1, n=20) and packable Filtek Р60 (Exp-Group 2, n=20) with the help of a transparent plastic mold. Every experimental group was randomly divided into two subgroups (A and B): polymerized filling samples of Exp-Subgroups 1A (n=10) and 2A (n=10) were put into the test right after polymerization; samples of Exp-Subgroups 1B (n=10) and 2B (n=10) were passed through a shear-strength test after exposure to four consecutive cycles of autoclaving. Shear-strength measurements were made in an Ultratest Machine (Ultradent, USA), which was adapted to perform a proper test. The incidence of secondary caries in both clinical groups (two incidents in Gl-Group 1 and one incident in Cl-Croup 2) was very low, and comparative analysis of obtained results did not reveal any significant difference between them. In relation to criteria of anatomy form, the percentage of alpha level of tooth restorations that were done with packable Filtek P60, was 38.9%. Bravo estimates had 50% of restored teeth. Tooth restorations with conventional Filtek Z250 had alpha level in 58.3% and bravo in 41.7% of cases. Occlusal contact and surface texture, the efficacy of CIICL management was better in teeth that had been treated with packable composite. Analysis of experimental findings revealed that the mean value of shear strength for Filtek Р60 filling samples, which were tested immediately after polymerization, was lower than the same parameter for Filtek Z250 on 25.8% (P

The aim of the present study was to assess the side effect of an aluminum chloride hemostatic agent on adhesion strength and microleakage of composite resin restorations bonded with the one-bottle total-etch adhesive system. Methods: We prepared 10 human tooth samples (extracted premolars for orthodontic purposes) in accordance with the Ultratest technique for the assessment of shear bond strength (SBS), and another 10 human tooth samples for microleakage assessment. The SBS tooth samples (n=10) were subjected to the two following tests: In Test 1, before traditional adhesive protocol, the aluminum chloride hemostatic agent was rubbed into a surface dentin for 60 sec with the help of a metal dento-infusor tip and washed with distilled water. In Test 2, just traditional wet bonding was performed. In the group of teeth (n=10) for microleakage assessment, we prepared two round artificial cavities of similar size (3 mm in diameter, 1 mm deep) in each tooth sample on the proximal surfaces with half in enamel and another half in root dentin. All created cavities (n=20) were divided into two subgroups. In cavities of Subgroup 1 (n=10), the adhesive protocol and filling with composite resin were performed after preliminary rubbing-in of the hemostatic agent. In Subgroup 2 (n=10), cavities were merely restored according to the rules for applying the one-bottle total-etch adhesive system. Assessment of microleakage was performed at the enamel margin and dentin margin. Scanning electron microscopy was used to evaluate the microstructure morphology of a hybrid layer, formed without the side effect of a hemostatic agent and after application of it. Results: The average score of SBS was 7.42±3.5 kg in Test 2 and 3.87±2.45 kg in Test 1. Therefore, the side effect of the aluminum chloride hemostatic agent was detrimental to the bond strength of the composite resin to human dentin and significantly decreased the quality of adhesion by 1.92 times (P0.05). However, the visual analysis of the dentin-composite junction of sectioned tooth samples demonstrated 2.1 times more microleakage in Subgroup 1 (1.7±0.95 CU) than in Subgroup 2 (0.8±0.79 CU), but the difference was not significant (P>0.05). In view of clinical situations with no possibility to escape the application of a hemostatic agent in cases of possible capillary hemorrhage and crevicular fluid leakage, it could be wise before running an adhesive protocol to cut off the portion of surface dentin that was exposed to an aluminum chloride hemostatic agent side effect.

The aim of the study was in vitro assessment of shear bond strength and micro-leakage after application of total-etch and self-etch adhesive systems. Materials and Methods: Four adhesive systems were chosen for assessment of adhesion performance: Contax (DMG, GmbH), Bond Force (Tokuyama Dental Corp. Japan Mfr), Te-Econom Bond (Ivoclar Vivadent, Liechtenstein) and Swisstec SL Bond (Coltene, Switzerland). The assessment of bond strength was performed on 20 tooth samples, which were prepared in accordance with the UltraTest technique for shear bond strength (SBS) estimation. The test was conducted at a crosshead speed of 1.0 mm/min and results were fixed in kilograms. The assessment of SBS was performed on enamel and dentin separately. Microleakage assessment of self-etch and total-etch adhesive systems was performed on 20 extracted non-carious upper human premolars with immersion in 1% methylene blue solution after thermocycling. Results: Good SBS results and microleakage values on the dentin substrate were obtained after application of the Contax self-etch bonding agent. But the values of bond strength to enamel and the extent of dye penetration within the composite-enamel interface were still better with the total-etch approach.

The aim of the present study was to examine the surface characteristics and values of removal torque of an implant surface subjected to sandblasting with 125µm Al2O3 particles with a following immersion in biomimetic fluid and to compare that surface with a machined implant surface. Study protocol: Forty-eight conical implants were initially made of second-grade titanium alloy. The diameter of implants was 4mm at the head and 2.6 at the apex, all implants were of 8 mm length and of large variable thread design. Half of them were subjected to sand blasting and immersion in biomimetic fluid at 37 ⁰C for four weeks with daily replenishment of solution until the moment of placement; another 24 implants were left with untreated machined surface. Three-dimensional roughness values were obtained with the help of confocal laser scanning microscope. Forty-eight implants were implanted in 12 dogs. Twenty-four implants were retrieved after a 6-week healing period following installation, and the remaining 24 were removed upon the completion of 16 weeks, using a torque calibrator ((BTG150CN-S TOHNICHI) with a 20 cN•m - 150 cN•m scale of force registration was applied for the measurements of the removal torque. Results: The mean 3-dimensional roughness value of biomimetically treated implant surfaces was 1.34±0.24µm and the mean roughness value measured for the machined surfaces was 0.33±0.04µm (P

The clinical and experimental efficiency of the soft-start polymerization technique in composite restorations was studied. In this study, 57 patients between 30 and 44 years of age with secondary caries had 158 restorations done using the photo-composite material Filtek Z250. The restorations performed were distinguished into two groups, the basis of the photo-polymerization method of employed (conventional polymerization technique and «soft-start» polymerization technique). The objects of the study also included the specimens of 18 extracted teeth. The analysis of the data indicates that employing the «soft-start» polymerization technique provides better integration of the composite material to the hard tissues of the tooth. This conclusion was best demonstrated in cases where the dentin was a connecting link in the chain «substrate-hybrid layer-composite».

The objective of this study was to compare the periodontal status in postmenopausal women with osteopenia and osteoporosis. Material and Methods: We examined 43 postmenopausal women aged from 55 to 74 years. Material assessment of bones in every patient was performed by means of dual energy X-ray absorptiometry (DXA) from two points on the skeleton – part of the femur neck and between the first and fourth lumbar vertebrae. A lipid blood test was done for patients of both groups. All patients were divided into two groups (the 1st with osteopenia, and the 2nd with osteoporosis). All patients were subjected to an oral clinical examination: the periodontal examination was composed of Plaque Index (PI), Pocket Score (PS), and Papillary Bleeding Index (PBI). X-ray analysis was performed for every patient. Results: The results of the clinical periodontal examination demonstrated that the mean PBI in patients in the 1st group had no significant differences from the PBI in patients in the 2nd group. PI value and PS findings in patients with general osteoporosis also had no statistical differences from the same parameters in patients with osteopenia. Conclusion: Under the circumstances of these patients’ characteristics and within the limits of the present study, we concluded that there is no significant difference in the periodontal status of postmenopausal women with systemic osteopenia and with osteoporosis.