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Purpose: To evaluate the effect of denatonium benzoate (DB) in histamine-induced model of inflammation and the effect of the selective H1 receptor agonist (2-(2-Pyridyl) ethylamine) on rat gastric smooth muscle strips pretreated with DB.Methods: The anti-inflammatory effect of DB was evaluated in vivo on histamine-induced rat paw edema. In vitro studies on spontaneous muscle contraction were performed on smooth muscle strips isolated from rat gastric corpus.Results: The results showed a well-defined anti-inflammatory effect of DB (15 mg/kg) during the early stage of rat paw edema at the 15th (p < 0.001), 30th (p < 0.01) and 60th min (p < 0.001) compared to control. In vitro experiments indicated reduced spontaneous contractile activity of smooth muscle strips to H1 receptor agonist in the presence of DB (0.5 μM). The vascular effects of histamine are mediated by H1 receptors. Substances, which reduce the effect of histamine on the H1 receptors could influence the early stage of histamine-induced inflammation.Conclusion: The results show that the anti-inflammatory activity of DB probably is related to its antagonistic activity on histamine H1 receptors. The results would contribute to the search for new antiinflammatory drugs. Keywords: Denatonium benzoate, Inflammation, Histamine, Muscle contraction

Lichen planus is a chronic mucocutaneous inflammatory disease aff ecting 1-2% of the general population with maximum prevalence of the disease in women above the age of 40. Its aetiology remains unclear and the pathogenesis is still the object of much speculation. It is considered to be an autoimmune disorder mediated mainly by the T-lymphocytes. The present paper presents the most well-known external agents (viruses in particular), internal agents like stress, and the heat shock protein thought to be trigger factors and describes the action of diff erent cells and proteins associated with the development of that disease. Diagnosis is based on clinical and histopathologic evidence; direct and indirect immunofluorescence techniques can also be of use. Despite the wide variety of therapeutic modalities, treatment outcomes are often insufficient. Currently, topical corticosteroids are widely accepted as a standard therapy, but also retinoids, calcineurin inhibitors and other immunosuppressants can be administered. Because of the aspect relevant to these drugs, priority is given to alternative harmless methods such as LLLT and PDLT. There is an ongoing controversy in the literature about the possible premalignant character of oral lichen planus, however, periodic followup is recommended.

Clinically, there is an urgent need to identify new therapeutic strategies for selectively treating cancer cells. One of the directions in this research is the development of biocompatible therapeutics that selectively target cancer cells. Here, we show that novel aminated graphene oxide (haGO-NH2) nanoparticles demonstrate increased toxicity towards human hepatocellular cancer cells compared to pristine graphene oxide(GO). The applied novel strategy for amination leads to a decrease in the size of haGO-NH2 and their zeta potential, thus, assuring easier penetration through the cell membrane. After characterization of the biological activities of pristine and aminated GO, we have demonstrated strong cytotoxicity of haGO-NH2 toward hepatic cancer cells—HepG2 cell line, in a dose-dependent manner. We have presented evidence that the cytotoxic effects of haGO-NH2 on hepatic cancer cells were due to cell membrane damage, mitochondrial dysfunction and increased reactive oxygen species (ROS) production. Intrinsically, our current study provides new rationale for exploiting aminated graphene oxide as an anticancer therapeutic.

Background: The erosive-atrophic form of oral lichen planus (OLP) is associated with severe pain and burning sensation and is often unresponsive to treatment. Topical corticosteroids are considered as a medication of first choice but they can produce adverse effects. Therefore, new therapeutic approaches are required. Aim: The aim of this study was to investigate the effectiveness of biomodulation with diode laser in patients presenting with long-standing erosive-atrophic OLP. Materials and methods: Twelve patients, clinically and histologically diagnosed with OLP, participated in this study. The level of pain and the clinical scores of total 59 lesions were recorded before treatment using visual analog scale and Thongprasom sign scoring system respectively. All patients received low level laser therapy (LLLT) with diode laser (810 nm) with parameters (0.5 W, 30 s, 1.2 J/cm2) three times weekly for a month. The response rate was assessed according to the decrease in pain and sign scores. Treatment efficacy index was calculated. Results: There was a significant reduction in pain after LLLT (p Conclusion: The present results indicate that LLLT is an effective and harmless modality for management of erosive-atrophic OLP.

The aim of this study is to evaluate the antihyperalgesic and antinociceptive effects of two formulations containing peat water extracts using a model of carrageenan-induced hyperalgesia, combined with a test with a mechanical stimulus, and a hot plate test. Rats were divided into seven groups (n = 6) and received local treatment with two peat formulations and two diclofenac formulations dissolved in carbopol gel and Wolff® basis creme, respectively. Carbopol gel, Wolff® basis creme and 0.9 % NaCl without tested substances were used as controls. Both peat formulations exerted an unambiguous antihyperalgesic effect 60 minutes after the treatment. In the hot plate test, the rats treated with the Wolff® basis creme peat formulation showed a tendency to prolonged latency on the first hour. The results could be explained by partial activation of peripheral α2-adrenoceptors and the possible COX-2 suppressive activity.

Purpose The aim of this study is to evaluate the effect of retigabine on the smooth muscle response to acetylcholine, adrenaline, α-and β-adrenoceptor agonists. Methods We studied the change in the spontaneous smooth muscle contraction of guinea pig gastric corpus strips before and after 20-min treatment with 2 μM retigabine. We also evaluated the effect of retigabine on the smooth muscle response to 10 μM acetylcholine, 1 and 10 μM adrenaline, 1 μM methoxamine, 0.1 μM p-iodoclonidine and 10 μM isoproterenol. Results We observed a significant reduction in the effects of all studied mediators and agonists when they were added to organ baths in the presence of retigabine. Retigabine diminished the effect of acetylcholine on the spontaneous smooth muscle activity. The effect was fully antagonized by XE-991 (Kv7 channel blocker), which supports our hypothesis about the role of KCNQ channels in the registered changes. The increase in the contraction force after adding of 1 μM adrenaline, methoxamine, and 0.1 μM p-iodoclonidine was also significantly smaller in presence of retigabine. However, comparing the effect of 10 μM adrenaline on the contractility before and after treatment with retigabine, we observed increased contractility when retigabine was present in the organ baths. Conclusion A possible explanation for the observed diminished effects of mediators and receptor agonists is that the effect of retigabine on smooth muscle contractility is complex. The membrane hyperpolarization, the interaction between Kv7 channels and adrenoceptors, and the influence on signaling pathways may contribute to the summary smooth muscle response.

The purpose of our study is to evaluate the effects of the translocator protein (TSPO) ligand etifoxine on muscle tone and locomotor activity. In addition, the mechanism of action of etifoxine on the presynaptic membrane and neuromuscular junction is investigated. These effects of etifoxine were examined employing the following methods: 1) in vivo experiments using bar holding test and activity cage test, and 2) comparative in vitro studies with nifedipine on indirectly-elicited twitches of striated abdominal muscle preparations. Etifoxine in doses 50 mg/kg and 100 mg/kg i.p. does not produce any significant changes in locomotor activity and muscle tone of intact rats. Nifedipine (10-5 М) induces a significant decrease in the muscle force of striated muscle preparations. Etifoxine (10-8-10-4 М) has no significant effect on indirectly-elicited twitch tension. Results show that the TSPO ligand etifoxine has no myorelaxant effect. The activation of TSPO is not associated with a reduction in muscle tone and motor impairment. Etifoxine does not affect the presynaptic membrane and its influence on L-type Ca2+-channels is insignificant. Etifoxine does not act as a competitive antagonist of acetylcholine and does not impair the impulse transmission in the neuromuscular junction.

Betahistine dihydrochloride, which is widely prescribed for the treatment of symptoms associated with Meniere’s syndrome, is generally administered orally in solid or liquid formulations. There is a strong need of profound investigation of alternative routes of administration of betahistine to overcome difficulties related to oral administration. The aim of this study was to evaluate betahistine cytotoxicity and permeability in vitro and to assess the drug’s relevance for incorporation in drug delivery systems for nasal administration. RPMI epithelial model was used to evaluate drug permeability in vitro. The cytotoxicity of betahistine was assessed by MTT test. Chitosan microspheres were used as a betahistine delivery system. RPMI 2650 formed a thick, impermeable cell layer on the apical side of the filter inserts and developed enough TEER values to confirm confluence. According to the obtained results, BET showed high permeability coefficients (Papp values in the range 2.3 × 10 −5 to 19 × 10 −5 ) and could, therefore, be successfully used in nasal drug delivery formulations. Also, BET exhibited a good safety profile regarding nasal epithelium toxicity. A dose-dependent reduction in cell viability was observed. The microspheres as drug delivery systems affected BET permeation profiles due to the presence of chitosan as an absorption enhancer.

Aim: To assess temperature changes at specified time intervals during Er:YAG laser scaling and root planing of surfaces with dental calculus. Materials and methods: Fifteen single-rooted teeth with advanced periodontal disease were extracted and fixed in a cylinder thermostat filled with distilled water at constant temperature (35.5°C). A specially designed thermal probe (type K thermocouple) accurate to ±0.1°C over the range from 20°C to 80°C was fitted into the pulp chamber of tooth sample. Scaling and root planing of the mesial and distal root surfaces was performed using an Er:YAG laser (Lite Touch, Syneron Dental, Israel) with a wavelength of 2940 nm, provided with a chisel tip, and at the following settings: output energy 100 mJ and 50 Hz, duration of irradiation - 40 sec, the tip in contact mode oblique to the root surface at an angle of approximately 10-15 degrees and water spray level 5-6. The temperature inside the pulp chamber was measured every 10 sec. Results: The temperature in the pulp chamber taken every 10 seconds and compared with the temperature of 35.5°C at baseline decreased by 1.6°C, 2.4°C, 2.5°C, and 2.5°C for the first, second, third and fourth measurement, respectively. These changes did not reach statistical significance. Conclusion: The Er:YAG laser does not increase the temperature inside the pulp chamber. The assessed changes do not depend on the duration of irradiation which was kept within 40 seconds. Therefore, this treatment modality causes no thermal damage to the pulp under the above defined conditions and can be considered safe.

Retigabine is a new antiepileptic drug with the main mechanism of action: activation of voltage-gated potassium channels (Kv7) represented in many tissues including the excitable cells-neuronal and muscular. The aim of this article is to determine the role of potassium channels located on the skeletal muscle membrane in the in vivo and in vitro reduction of muscle contractile activity induced by retigabine. We studied the effects of retigabine on the motor function in vivo using a bar holding test and exploratory activity using open field test in rats. Electrical field stimulation (EFS) was applied to skeletal muscle strips in vitro in order to evaluate muscular activity. We registered a significant decrease in the muscle tone and exploratory activity of rats, treated orally with 60 mg/kg bw retigabine. In vitro experiments showed decrease in the maximal muscle force of strips in the presence of retigabine in the medium after both indirect (nerve-like) and direct (muscle-like) stimulation. The effects were fully antagonized by XE-991 (Kv7 channel blocker), which supports our hypothesis about the relation between these types of potassium channels and the observed change in the muscle force. Based on these results, we can conclude that skeletal muscle Kv7 channels play a significant role in the myorelaxation and reduced muscle force registered after treatment with Kv7 channels openers (e.g., retigabine). The hyperpolarization of skeletal muscle membrane caused by accelerated K(+) efflux may be the underlying cause for the effect of retigabine on the muscle tone.

Linker histones are major players in chromatin organization and per se are essential players in genome homeostasis. As the fifth class of histone proteins the linker histones not only interact with DNA and core histones but also with other chromatin proteins. These interactions prove to be essential for the higher levels of chromatin organization like chromatin loops, transcription factories and chromosome territories. Our recent results have proved that Saccharomyces cerevisiae linker histone – Hho1p, physically interacts with the actin-related protein 4 (Arp4) and that the abrogation of this interaction through the deletion of the gene for the linker histone in arp4 mutant cells leads to global changes in chromatin compaction. Here, we show that the healthy interaction between the yeast linker histone and Arp4p is critical for maintaining genome stability and for controlling cellular sensitivity to different types of stress. The abolished interaction between the linker histone and Arp4p leads the mutant yeast cells to premature ageing phenotypes. Cells die young and are more sensitive to stress. These results unambiguously prove the role of linker histones and chromatin remodelling in ageing by their cooperation in pertaining higher-order chromatin compaction and thus maintaining genome stability.

Comet assay is an invaluable tool in DNA research. It is widely used to detect DNA damage as an indicator of exposure to genotoxic stress. A canonical set of parameters and specialized software programs exist for Comet assay data quantification and analysis. None of them so far has proven its potential to employ a computer-based algorithm for assessment of the shape of the comet as an indicator of the exact mechanism by which the studied genotoxins cut in the molecule of DNA. Here, we present 14 unique measurements of the comet image based on the comet morphology. Their mathematical derivation and statistical analysis allowed precise description of the shape of the comet image which in turn discriminated the cause of genotoxic stress. This algorithm led to the development of the "CometShape" software which allowed easy discrimination among different genotoxins depending on the type of DNA damage they induce.

Fragestellung: Klinisch werden immer wieder die entzundungshemmenden Wirkungen von Torf bei der Behandlung rheumatologischer Erkrankungen beobachtet. Bislang ist aus der Torfforschung nicht klar hervorgegangen, warum ein Moorbreibad antientzundliche Effekte aufweist. Die thermischen Effekte alleine konnen diese Wirkungen nicht erklaren. Material und Methoden: Es wurde daher die Wirkung von wasserigem Torfextrakt (WTE), hergestellt aus Badetorf auf die Aktivitat der Cyclooxygenase und ihre beiden Isoformen COX-1 und COX-2 untersucht und diese mit Indometacin verglichen. Ergebnisse: Das Verhaltnis zwischen den notwendigen Konzentrationen zu einer 50% tigen Unterdruckung der Aktivitaten der COX-1 und COX-2 Isoformen betragt 1,79. Diskussion: Bei Indometacin betragt dieses Verhaltnis 0,17, ist also ca. 10-mal geringer, als das von WTE. Schlussfolgerung: Die Resultate der vorliegenden Wirkungsuntersuchungen lassen es zu, den wasserigen Torfextrakt als spezifischen COX-2 Blocker einzustufen.

Purpose: The anti-inflammatory effects of 1,8‑cineole (eucalyptol) in the treatment of acute bronchitis and treatment of chronic airway diseases like asthma as well as hay fever have been observed in clinical practice for some time. The anti-inflammatory effect has been proven in numerous studies. Material and methods: The effect of 1,8-cineole on the activity of cyclooxygenase and its two isoforms (COX‑1 and COX‑2) were analysed and compared with the effects of indomethacin and celecoxib. Results: The ratio between the concentrations required to achieve 50% inhibition of COX‑1 and COX‑2 isoform activity was found to be 73.5. Discussion: For indomethacin, the ratio is 9.71 and for celecoxib 79.5. For indomethacin, it is about 10 times less than that of 1,8‑cineole. Conclusion: The present study provides useful data suggesting that 1,8‑cineole is a specific COX‑2 blocker.

The Sporobolomyces salmonicolor AL1 Antarctic strain was cultivated and two bioproducts were obtained: exopolysaccharide and biomass. The biologically active substances ergosterol, torularhodin, torulene, β-carotene and CoQ10 were extracted from the biomass and were quantified as follows: ergosterol 5.2 ± 0.2 mg/g, torularhodin 458.3 ± 24.5 μg/g, torulene 273.7 ± 14.5 μg/g, β-carotene 129.2 ± 7.3 μg/g and coenzyme Q10 (CoQ10) 236.1 ± 12.1 μg/g. Their antioxidant activity was estimated according to the cathode voltammetry method. The most pronounced antioxidant activity (according to trolox) was exhibited by β-carotene 3.78, followed by CoQ10 3.60, both of them being the main contributors to the total extract activity of 3.19. The biologically active metabolites in combination with exoglucomannan as emulsifier were used for the creation of model emulsion systems characterised by great stability. The absorption of UVA rays by the model emulsions was studied.

A series of different 1-monosubstituted and 1,1-disubstituted 1,2,3,4-tetrahydro-isoquinolines was synthesized in high yields from different ketoamides. We have developed a convenient method for the synthesis of disubstituted derivatives by interaction of ketoamides with organomagnesium compounds, followed by cyclization in the presence of catalytic amounts of p-toluenesulfonic acid (PTSA). A number of substituents at the C-1 in the isoquinoline skeleton were introduced varying either carboxylic acid or organomagnesium compound. Some of the obtained 1,1-dialkyl-1,2,3,4-tetrahydro-isoquinolines possess contractile activity against guinea pig’s gastric smooth muscle preparations.

Purpose : To determine the effects of etifoxine on directly-elicited twitch tension of isolated rat nerveskeletal muscle preparations and to propose a possible explanation of the mechanism of the observed effect. Methods : Striated muscles contractile activity was elicited by electrical field stimulation. The effects of etifoxine and nifedipine on direct single twitch response were studied. Results : The results demonstrate that the effect of etifoxine on skeletal muscle depends on the concentrations: low concentrations (10 -8 М and 10 -7 М) have little effect on twitch tension, whereas higher concentrations (10 -6 М and 10 -5 М) induced a significant decrease in the direct single twitch response in comparison to controls. The mean IC 50 (reduction of directly-elicited twitch tension) of etifoxine was 0.85 x 10 -6 M. The selective L-type calcium channel blocker nifedipine (10 -5 М) induced a greater decrease in the muscle force than 10 -6 М etifoxine. The different abilities of etifoxine and nifedipine to reduce direct single twitch response may be related to their distinct mechanisms of action. The observed effect of etifoxine could be more complex. Probably etifoxine acts as a non-selective agent not only on L-type calcium channels Cav1.1 localized in sarcolemma but also on 18-kDa translocator protein (TSPO) in skeletal muscle. Conclusion : Etifoxine-induced reduction of direct twitch responses could be attributed to an effect on TSPO and Cav1.1. Knowledge of the effects of TSPO ligands on the contraction of skeletal muscle might explain the role of TSPO in muscle contractility. Keywords : Etifoxine, TSPO, Calcium channels, Direct single twitch response, Striated muscle

Background: The cosmetic oral mucosa tattoos occur infrequently but the social stigma that may be associated generally with tattoos is motivating factor for its removal. The development of infrared lasers has revolutionized the ability to remove cosmetic oral tattoo effectively. The wave-length of choice is 1,064 nm but there is no relevant histological data regarding effects of Nd:YAG laser on oral tissues after tattoo removal. The aim of this study is to provide histological evidences and to clarify the healing processes in oral mucosa after tattoo removal with 1,064 nm wavelength laser. Methods: Five patients with professional black tattoo of inner lip were included in this study. The clinical procedures were performed using 1,064 nm wavelength. Two equal specimens were taken from the treated and non-treated sites for further histological evaluation. Results: The specimens after the treatment revealed fragmentation of black ink particles up to 1.5 mm below the surface. Mild fibrosis was observed in the superficial submucosal area where collagen fibers replaced the pigment-containing cells altered by the laser. Clinically, the treatment results showed excellent recovery of the oral mucosa. One year later, the laser treated areas were healthy and without esthetical and functional disturbances. Conclusions: Both histological and clinical results advocated Nd:YAG laser treatment as safe and very effective means of removing cosmetic tattoos on the oral mucosa.

The patients’ discomfort during CT colonography determines which method is used and its frequency of use. The discomfort is largely associated with the colon’s insufflation with gas. A system for an automatic room-air insufflation has been developed that ensures a continuous and steady air insufflation and an increase in colonic pressure and enables a relatively fast decompression. This system provides constant pressure monitoring and can alert the operator, if necessary. The degree of discomfort was evaluated for 36 patients, who were subjected to manual and automated air insufflation. The degree of the colonic distension achieved by the two methods was compared. The data analysis showed a significantly lower level of discomfort in patients with automated air insufflation. The degree of colonic distension was evaluated by comparing the diameters of similar segments of the colon, as well as by the subjective opinion of the operator. The distension with automated air insufflation was higher than that with manual air insufflation. In some cases there was a significant difference (P

UNLABELLED Betahistine dihydrochloride is a histamine-like drug widely used in relieving the symptoms associated with Meniere's syndrome. Pharmacokinetic studies of betahistine have demonstrated that it has a short plasma half-life of 3-4 hours. In such cases frequent administration of the drug is required in order to keep plasma concentration within the therapeutic range. However, this may lead to noncompliance and aggravate patients' comfort. An advanced approach for achieving sustained release of drugs is their incorporation in microparticulate carriers. AIM To design a sustained release microsphere formulation of betahistine providing reduced dose frequency and lower risk of side effects occurrence. MATERIALS AND METHODS Betahistine-loaded chitosan microspheres were obtained via W/O emulsion solvent evaporation technique and were characterized for particle size, drug loading and entrapment efficiency. Drug release into phosphate buffer saline pH 7.4 was performed and dissolution profiles of the formulations were obtained. To study the mechanism of drug release from the microspheres the dissolution data was fitted to various mathematic models. RESULTS Betahistine-loaded microspheres were produced with a high drug loading and entrapment efficiency. The microcarriers were spherical in shape with mean particle size of 3.82 μm to 7.69 μm. Betahistine release studies from the microspheres showed similar and slightly increasing dissolution profiles. The drug release proceeded in a controlled manner following Fickian diffusion. CONCLUSION The obtained results suggest that betahistine-loaded chitosan microspheres prepared by solvent evaporation method are capable of sustained release of drugs and therefore can be used as drug delivery systems in the treatment of Meniere's syndrome.

The Sporobolomyces salmonicolor AL(1) Antarctic strain was cultivated and two bioproducts were obtained: exopolysaccharide and biomass. The biologically active substances ergosterol, torularhodin, torulene, β-carotene and CoQ(10) were extracted from the biomass and were quantified as follows: ergosterol 5.2 ± 0.2 mg/g, torularhodin 458.3 ± 24.5 μg/g, torulene 273.7 ± 14.5 μg/g, β-carotene 129.2 ± 7.3 μg/g and coenzyme Q(10) (CoQ(10)) 236.1 ± 12.1 μg/g. Their antioxidant activity was estimated according to the cathode voltammetry method. The most pronounced antioxidant activity (according to trolox) was exhibited by β-carotene 3.78, followed by CoQ(10) 3.60, both of them being the main contributors to the total extract activity of 3.19. The biologically active metabolites in combination with exoglucomannan as emulsifier were used for the creation of model emulsion systems characterised by great stability. The absorption of UVA rays by the model emulsions was studied.

The effect of different doses of visible (Vis), ultraviolet-capital A, Cyrillic (UVA), and mixed light (UVA + Vis) upon coenzyme Q(10) (CoQ(10)) and beta-carotene synthesis and biomass yield by the Sporobolomyces salmonicolor AL(1), Cryptococcus albidus AS(55), Cryptococcus laurentii AS(56), and C. laurentii AS(58) strains isolated from Antarctic samples was investigated. The beta-carotene concentration in the red strain biomass increased by 52% under irradiation with 11 J/cm(2) Vis, and the CoQ(10) concentration rose by 37% in relation to the control quantity obtained through dark cultivation. Under irradiation with 6 J/cm(2) UVA, the S. salmonicolor AL(1) strain synthesized 15% more beta-carotene; C. albidus AS(55), 22%; C. laurentii AS(56), 44%; and C. laurentii AS(58), 35% in relation to the control quantity. Irradiation with a low UVcapital A, Cyrillic + Vis dose significantly stimulated beta-carotene biosynthesis by the strains of the Cryptococcus genus (87%, 138%, and 100%), whereas S. salmonicolor AL(1) increased the beta-carotene content to a smaller degree (55%). Higher doses of all three irradiation types inhibited beta-carotene accumulation. Vis suppressed CoQ(10) biosynthesis in the Cryptococcus strains, whereas UVcapital A, Cyrillic and UVcapital A, Cyrillic + Vis inhibited it in all four strains. The S. salmonicolor AL(1) strain pre-treated with 0.02 J/cm(2) UVA synthesized twice as much CoQ(10) and beta-carotene when cultivated in the presence of Vis light in an 11-J/cm(2) dose.

Ендодонтско представлява лечебна процедура в денталната медицина, при която се елиминират инфектираните тъкани и причинителите на инфекциозния процес от кореноканалната система и лекуваният зъб се предпазва от бъдеща бактериална контаминация. Акцентите в това определение са два. Единият пада върху отстраняване на засегнатите тъкани и причината за възникване и протичане на ендодонтската патология, а другият е свързан с предпазване на обекта на лечение от реконтаминация в краткосрочен и дългосрочен план. Съвременната ендодонтското лечение в повечето случаи се провежда в едно посещение, което се приема като оптимален подход В някои случаи се налага и многосеансов подход. Това изисква ендодонтският достъп да бъде обтуриран с материал за временно възстановяване, който да изолира оперативното поле от оралната среда до следващото посещение. От временното възстановяване на ендодонтския кавитет изходът от лечението. Всеки компромис с качеството на използвания материал, начинът му на поставяне, времето, през което той престоява в кавитета, както и цялостното му отстраняване преди окончателното възстановяване, може да доведе до компрометиране на изхода от терапията. Endodontic treatment is a procedure in dentistry that eliminates infected tissues, bacteria and bacteria byproducts from the root canal system and the treated tooth is protected from recontamination. According to this statement, it needs to be emphasized the imporatance of the removal of all etiological factors of the endodontic pathology. On the other hand the isolation of the endodotic space from recontamination during the post operative period is also accepted as crucial for the treatment outcome. Contemporary endodontic treatment in most cases is single visit, which is considered as optimal clinical approach. In some cases, a multi-visit therapy is required. In these cases the endodontic access needs to be obturated with temporary restorative material to isolate the operative field from the oral environment until the next appointment. This procedure may influence the treatment outcome. Any prpblem with the quality of the material used, the method for temporary restoration, the time until the next appiontment, as well as the complete removal of the material before the post endodontic restoration, may result in a poor short and long term prognosis of the treated tooth.

С развитието на денталната имплантология и непрекъснато нарастващия брой поставени импланти в световен мащаб терапията на усложненията придобива все по-голяма актуалност. Периимплантитът според различни данни се установява при 42% (28 до 56%) от пациентите и 27% (12 до 43%) от имплантите. Това определя необходимостта от търсене на предвидими съвременни методи за лечението на това заболяване. Лазерите, използвани в денталната медицина, са средства, даващи обещаваща ефективност при деконтаминацията на имплантната повърхност и периимплантните тъкани, дебридмен и тъканна аблация. Тези апарати генерират лазерен лъч в различни среди и с различна дължина на вълната, което определя и вариабилност във физичните параметри и въздействие върху структурите в имплантния интерфейс. Детайлното проучване на това въздействие дава възможност за селектирането на лазер с оптимална ефективност и без да уврежда и модифицира имплантното тяло и прилежащите меки и твърди тъкани. От трите типа лазери, които могат да бъдат използвани при консервативното и хирургично лечение на периимплантит с най-добри параметри и биологични ефекти е Er:YAG лазерът според данните, получени чрез лабораторни, експериментални и клинични проучвания, описани в настоящия дисертационен труд., With the development of dental implantology and the ever-increasing number of implants placed worldwide, the therapy of complications is becoming more and more relevant. According to various data, peri-implantitis was found in 42% (28 to 56%) of patients and 27% (12 to 43%) of implants. This determines the need to look for predictable contemporary methods for the treatment of this disease. Lasers used in dental medicine are means that give promising efficiency in the decontamination of the implant surface and periimplant tissues, debridment and tissue ablation. These devices generate a laser beam in different environments and with different wavelengths, which also determines variability in physical parameters and impact on structures in the implant interface. The detailed study of this impact makes it possible to select a laser with optimal efficiency and without damaging and modifying the implant body and adjacent soft and hard tissues. Of the three types of lasers that can be used in the conservative and surgical treatment of peri-implantitis with the best parameters and biological effects is the Er:YAG laser according to the data obtained through laboratory, experimental and clinical studies described in the current dissertation work.