The Impact of COVID-19 on the Oral Bacterial Flora in Patients Wearing Complete Dentures and on the Level of Exhaled Nitric Oxide as a Marker of Inflammation.

BACKGROUND: Exhaled nitric oxide is helpful in the diagnosis of the inflammation process. The study aimed to analyze the impact of the COVID-19 disease on the oral bacterial flora of patients using complete dentures with a diagnostic device that measures the level of NO in exhaled air. MATERIALS AND METHODS: The study included patients using upper and lower acrylic complete dentures. All patients participating in the study were vaccinated against COVID-19. The patients were divided into two groups. A dental examination was conducted in each group. The NO concentration was measured using the Vivatmo Pro device. An oral microbiological examination was performed by taking a swab from the bottom of the mouth. RESULTS: There were no statistically significant differences in the distribution of NO in relation to the number of bacteria from isolated families in the study and control groups and no statistically significant correlations between the level of NO and the number of bacteria from all families in the control and study group. Significantly higher NO values were present in the vaccinated and COVID-19-positive history population compared to the vaccinated and with no COVID-19 history population (patients with no clinical symptoms of infection or unaware they had COVID-19). CONCLUSIONS: There are statistically significant differences in NO distribution in the considered populations: vaccinated and sick, and vaccinated and with a negative history of COVID-19. The measurement of NO in exhaled air can be a complementary, non-invasive diagnostic and inflammation monitoring method.

An Evidence-Based Review of Application Devices for Nitric Oxide Concentration Determination from Exhaled Air in the Diagnosis of Inflammation and Treatment Monitoring.

The measurement of nitric oxide (NO) in exhaled air is used in diagnostics and monitoring the pathologies not only in the respiratory system but also in the oral cavity. It has shown a huge increase in its level in asthma and diseases of the oral cavity. It seems reasonable to undertake research on the impact of inflammation on the level of NO in exhaled air. The aim of the study is to make an evidence-based review of the application of NO levels in exhaled air in the diagnosis of inflammation and treatment monitoring on the basis of selected measuring devices. METHODS AND RESULTS: This paper presents an example of the application of NO measurement in exhaled air in individual human systems. Selected measuring devices, their non-invasiveness, and their advantages are described. DISCUSSION: The usefulness of this diagnostic method in pathologies of the oral cavity was noted. CONCLUSIONS: Measuring the level of NO in exhaled air seems to be a useful diagnostic method.

Yttrium Trifluoride as a Marker of Infiltration Rate of Decalcified Root Cementum: An In Vitro Study.

Research related to the development of a dental infiltrant for minimally invasive treatment of initial caries of hard dental tissues is presented. The formulation of the developed infiltrant material includes typical methacrylate monomers used in dentistry, an author's adhesion monomer containing metronidazole, a photoinitiating system and yttrium trifluoride (YF3). The main objective of the study was to evaluate penetration into decalcified root cementum using scanning electron microscope of an experimental preparation with the characteristics of a dental infiltrant compared to a commercial preparation with the addition of YF3 as a contrast agent. Microscopic observations showed that YF3 particles virtually did not penetrate deep into the root cementum-this was mainly due to the particle size of YF3. Observations of cementum and root dentin tissue infiltration: resin tissue infiltration was visible to a depth of about 80 to 120 µm without the use of a tracer, which, due to agglomeration and particle size, remained on the cementum surface or in the resin used for inlaying. There were no differences between the degree of penetration of an experimental preparation with the characteristics of a dental infiltrant, as compared to a commercial preparation.

Pilot Study of Use of Nitric Oxide in Monitoring Multiple Dental Foci in Oral Cavity-A Case Report.

BACKGROUND: The most common cause of implant loss and deteriorating restoration aesthetics is infection and chronic inflammation of the tissues around the implants. Inflammation in the oral cavity, confirmed by clinical and histopathological examination and determination of exhaled nitric oxide, is a situation which may cause the complications on the whole human body. Elimination of the patology in the oral cavity in some cases is the only resonable treatment. The aims and objectives of our work is to present a gradual treatment of advanced infalmmation and present huge reduction stamp of inflammation measured with marker nitric oxide (NO) in exhaled air. MATERIALS AND METHODS: Simple treatment containing elimantion of pathology in the oral cavity was conducted. Patient that came to the dental practice suffered from the inflammation caused by lack of proper hygiene. First aid in this situation was to eliminate the inflammation which may affect negatively for general health. At first visit full hygienization was performed, at the second visit roots of abutment teeth and implants were removed under local anesthesia along with cystic changes. RESULTS: The hygiene precedures and extraction of the unsteady inflammationprosthetic restorations significantly decreased the level of NO in exhaled air. CONCLUSIONS: During the examination of the patient coming to the dental practice great attention should be paid to the coexistence of pathologies related to the oral cavity. Omission of a dental examination and possible elimination of odontogenic foci may affect the implication of the results of general diagnostics and subsequent treatment. Measuring the level of NO on exhaled air seems to be useful diagnostic method.

The Problem of Halitosis in Prosthetic Dentistry, and New Approaches to Its Treatment: A Literature Review.

The aim of this work is a review of recent scientific literature about intra-oral halitosis among patients using dentures. Halitosis is a condition in which an unpleasant smell comes out of the oral cavity, which is caused mainly by volatile sulfur and non-sulfured compounds. The etiology of halitosis may be intra- or extra-oral; in most patients, however, it is due to the activity of microorganisms in the oral cavity. The problem of the occurrence of intra-oral halitosis has accompanied patients for many years. In dental prosthetics, the problem of halitosis occurs in patients using removable or fixed dentures. In both cases, new niches for the development of microorganisms may be created, including those related to intra-oral halitosis. It should be noted that dentures-both fixed and removable-are a foreign body placed in the patient's oral cavity which, in case of insufficient hygiene, may constitute a reservoir of microorganisms, causing this unpleasant condition. Conventional treatment of intraoral halitosis reduces microbial activity via chemical and/or mechanical action. Currently, the search for new strategies in the treatment of halitosis is in progress. One idea is to use photodynamic therapy, while another is to modify poly(methyl methacrylate) (PMMA) with silver and graphene nanoparticles. Additionally, attempts have been made to combine those two methods. Another unconventional method of treating halitosis is the use of probiotics.

Analysis of Changes in the Tensile Bond Strenght of Soft Relining Material with Acrylic Denture Material.

Abrasions and pressure ulcers on the oral mucosa are most often caused by excessive pressure or incorrect fitting of the denture. The use of soft relining materials can eliminate pain sensations and improve patient comfort. The main functional feature of soft elastomeric materials is the ability to discharge loads from the tissues of the mucosa. (1) Background: The aim of the work was a comparative laboratory study of ten materials used for the soft lining of acrylic dentures. (2) Methods: There were materials based on acrylates (Vertex Soft, Villacryl Soft, Flexacryl Soft) and silicones (Sofreliner Tough Medium, Sofreliner Tough Medium, Ufi Gel SC, GC Reline Soft, Elite Soft Relining, Molloplast). Laboratory tests include the analysis of the tensile bond strength between the relining material and the acrylic plate of the prosthesis. The tests were conducted taking into account 90-day term aging in the distilled water environment based on the methodology presented in the European Standard ISO 10139-2. (3) Results: After three months of observation, the highest strength of the joint was characterized by Flexacryl Soft acrylic, for which the average value was 2.5 MPa. The lowest average value of 0.89 MPa was recorded for the GC Reline Soft silicone material. Over time, an increase in the value of the strength of the combination of acrylic materials and a decrease in these values in the case of silicone materials was observed. (4) Conclusion: Each of the tested silicone materials showed all three types of damage, from adhesive to mixed to cohesive. All acrylic-based materials showed an adhesive type of failure. Time did not affect the type of destruction.

Assessment of the Potential Ability to Penetrate into the Hard Tissues of the Root of an Experimental Preparation with the Characteristics of a Dental Infiltratant, Enriched with an Antimicrobial Component-Preliminary Study.

Infiltration is a method of penetration with a low viscosity resin that penetrates deep into demineralised tooth tissue and fills the intergranular spaces, hence reducing porosity. Carious lesions initially located at the enamel-cement junction are usually found in elderly patients. Those spots are predisposed to bacterial adhesion originating both from biofilm and from gingival pocket bacteria. The aim of this study was to evaluate the penetration of an experimental preparation, which has the characteristics of a dental infiltrant, enriched with an antibacterial component, into the decalcified root cement tissues of extracted human teeth in elderly patients. An experimental preparation with the characteristics of a dental infiltrant was prepared, applied, and polymerised on the surface of extracted, previously decalcified human teeth. The control sample was Icon (DMG, Hamburg, Germany). The ability of the preparations to penetrate deep into the root cement was evaluated using scanning electron and light microscopy. The study showed that an experimental preparation could potentially be used for treatment of early carious lesions within the tooth root in elderly patients, among others, as it penetrates deep into demineralised tissues. More research is needed.

Analysis of the Hardness of Soft Relining Materials for Removable Dentures.

The main functional feature of elastomeric soft linings materials is the ability to discharge loads in the tissues of the mucosa. As a result, there are fewer injuries to the mucosa and chewing ability increases. In addition, these prostheses are more comfortable in the patient's opinion. To obtain the equal distribution of forces on the muco-bone basis and to reduce the traumatizing effect of the denture plate for patients using full dentures, soft lining materials can be used. AIM OF THE STUDY: the aim of the work was a comparative laboratory study of ten materials used for soft lining of acrylic complete dentures. METHODOLOGY: Materials based on acrylates (Vertex Soft, Villacryl Soft, Flexacryl Soft) and on silicones (Sofreliner Tough Medium, Sofreliner Tough Medium, Ufi Gel SC, GC Reline Soft, Elite Soft Relining, Molloplast) were compared. Laboratory tests include tests of changes in Shore'a A hardness of soft lining material. The tests were conducted taking into account 90 day term aging in the distilled water environment based on the methodology presented in the European Standard ISO 10139-2. RESULTS: For most silicone materials, only small changes in hardness were found in the range of 0.7 (Ufi Gel SC) to 3.3 (Sofreliner Tough Medium) on the Shore A scale. The exception was GC Reline Soft, for which a marked increase in hardness was noted. All materials based on acrylates were characterized by successive increase in hardness over time. However, in the case of the Vertex Soft material, the increase in hardness was relatively small (5.5 ShA).

Study of Cytotoxic Properties of an Experimental Preparation with Features of a Dental Infiltrant.

Microinvasive dentistry is based on the treatment of early carious lesions with the use of dental infiltrants. The commercially available Icon dental infiltrant does not contain any bacteriostatic component. An experimental preparation enriched with the missing component was synthesised. The aim of this study was to evaluate the cytotoxicity of the experimental preparation. Mouse fibroblasts of the L-929 lineage were used for the in vitro study. Cell morphology and viability were assessed. In the cytotoxicity analysis, it was shown that the experimental preparation (42.8 ± 10.3) after 24 h at two-fold dilution showed similar cytotoxicity to Icon (42.7 ± 8.8) (p > 0.05), while at four-fold dilution experimental preparation (46.7 ± 3.1), it was less toxic than Icon (34.2 ± 3.1) (p < 0.05). The experimental preparation has the potential to provide an alternative to the Icon commercial preparation. Further research is needed to evaluate the cytotoxicity of the experimental preparation over a longer period of time.

[Spine arrangement during work in sitting position and occurrence of pain among dentists and medical assistants]. / Ustawienie kregoslupa podczas pracy w pozycji siedzacej a dolegliwosci bólowe u stomatologów i asystentek medycznych.

BACKGROUND: Back pain is common among people working in the sitting position. Quality of the sitting position depends among others on the standard of work station. Dental units are built on the basis of contemporary ergonomic workplace concepts, while medical assistant workstations are typically computer office workstations. The purpose of the study was pain estimation in association with the identification of the spine arrangements during sitting work with better and worse ergonomic adjustment. MATERIAL AND METHODS: The study involved 80 women working in the sitting position suffering from pain - 40 dentists working on dental units with a higher ergonomic potential and 40 medical assistants working on stations with lower ergonomic potential. The study included interviews, pain assessment and working spine arrangements analysis using the ultrasonographic measurement system. RESULTS: There were exceeds of work parameters in particular segments of the spine observed in all examined persons. The relationship between pain intensity and work parameters as frontal bending amplitude of lumbar spine segment, transversal amplitude of cervical spine segment and transversal amplitude of lumbar spine segment were observed in the group of dentists. There was observed the relationship between pain severity and the values of sagittal bending amplitude of cervical spine segment and thoracic spine segment in the group of medical assistants. Other determinants of pain also have been identified. CONCLUSIONS: Exceeded values of work parameters were observed amongst subjects working both at the higher and the lower ergonomic potential work stations. The working postures of people working in the sitting position are similar only to their external characteristics. Pain depends on working position. The pain intensity is determined by other factors: length of professional experience, duration of the pain, the number of working hours per week, body mass index (BMI). Med Pr 2018;69(5):509-522.

A Comparative Study of Oral Microbiota in Infants with Complete Cleft Lip and Palate or Cleft Soft Palate.

Few reports have been published on the early microbiota in infants with various types of cleft palate. We assessed the formation of the oral microbiota in infants with complete cleft lip and palate (CLP n = 30) or cleft soft palate (CSP n = 25) in the neonatal period (T1 time) and again in the gum pad stage (T2 time). Culture swabs from the tongue, palate, and/or cleft margin at T1 and T2 were taken. We analysed the prevalence of the given bacterial species (the percentage) and the proportions in which the palate and tongue were colonised by each microorganism. At T1, Streptococcus mitis (S. mitis) were the most frequently detected in subjects with CLP or CSP (63% and 60%, resp.). A significantly higher frequency of methicillin-sensitive Staphylococcus aureus (S. aureus MSSA) was observed in CLP compared to the CSP group. At T2, significantly higher percentages of S. mitis, S. aureus MSSA, Staphylococcus epidermidis, and members of the Enterobacteriaceae family were noted in CLP infants compared to the CSP. S. mitis and Streptococcus sanguinis appeared with the greatest frequency on the tongue, whereas Streptococcus salivarius was predominant on the palate. The development of the microbiota in CLP subjects was characterised by a significant increase in the prevalence of pathogenic bacteria.

The analysis of cytotoxicity of an experimental preparation used for the reduction of dentin hypersensitivity.

BACKGROUND: The problem of effective treatment of dentin hypersensitivity is still valid and not fully resolved. OBJECTIVES: The aim of the study was to evaluate the potential toxicity against body tissues of an experimental preparation which is supposed to reduce dentin hypersensitivity and to compare it to a commercial formulation Seal & Protect (Dentsply) by means of measuring the activity of mitochondrial dehydrogenases (the MTT assay). MATERIAL AND METHODS: The study used an original protective formulation which is supposed to eliminate hypersensitivity of dentin. A commercial preparation Seal & Protect (Dentsply) was used as the comparative material. Cytotoxic activity of the tested preparations (experimental and commercial) on murine lymphocyte cells CCL-1™ (NCTC clone 929) was determined in indirect contact with the use of the MTT test that measured the activity of the mitochondrial dehydrogenase enzyme. RESULTS: A comparison of the results obtained in the MTT assay for the commercial preparation Seal & Protect (Dentsply) and the experimental formulation indicates that an experimental formulation has considerably lower cytotoxicity before polymerization, when compared to the commercial formulation, regardless of its dilution. However, after the polymerization of the commercial formulation was completed, its parameters improved significantly, especially for higher dilution values (1 : 10 and 1 : 15). Results for the experimental formulation are higher, particularly for the dilution value of 1 : 5. The overall summary of the results obtained from the MTT assay for the commercial preparation Seal & Protect (Dentsply) and the experimental formulation indicates that the experimental formulation had a significantly lower cytotoxicity before polymerization in comparison with the commercial formulation, regardless of dilution. CONCLUSIONS: Estimating the biocompatibility of a given material is not simple, and measurement methods are rapidly evolving, as more and more is known about the interaction between dental materials and oral tissues, and also as a result of improvements in testing techniques.

Oral Health of Patients Treated with Acrylic Partial Dentures Using a Toothpaste Containing Bee Product.

This study was carried out to investigate the influence of a propolis and tee tree oil-containing hygienic agent on selected oral health parameters, oral microflora, and the condition of periodontal health. Thirty-seven patients who underwent oral rehabilitation with a removable acrylic denture were selected and randomly assigned into two groups: study group (A) which received a newly formulated propolis and tee tree oil-containing toothpaste or a control group (C) without an active ingredient. API, S-OHI, and mSBI were assessed in three subsequent stages. During each examination swabs were employed for microbiological inoculation: in the study group after 4 weeks use of the active toothpaste showed a decrease in the number of isolated microorganisms. In the control group, after 4 weeks use of the toothpaste without active ingredients resulted in increase in the number of the isolated microorganisms. Improvements in hygiene and the condition of periodontium were observed in patients using active toothpastes. In the study group the oral flora diversity was reduced by the decrease in the number of cultured microorganism species, while in the control group an increase in the number of cultured microorganisms and their species was observed.

Foreign body of endodontic origin in the maxillary sinus.

Foreign bodies found in the maxillary sinus include tooth roots, burs, dental impression material, root-filling materials, dental implants, and needles. The purpose of this paper was to present an unusual case of a large foreign body of endodontic origin (root-filling material) removed from the maxillary sinus. A 45-year-old generally healthy male patient reported to the Department of Conservative Dentistry with Endodontics of the Medical University of Silesia, because of orbital and buccal pain on the right side of his face and headaches in the preceding 6 months. Those symptoms were associated with the end of endodontic treatment of teeth 14 and 16. Periapical X-rays, including of teeth 14 and 16, showed the presence of root canal filling with extrusion of endodontic obturation material beyond the apices of tooth 14. In the case of tooth 16, a completely filled palatal canal and incompletely filled buccal canals were found. There was also an irregular dimness at the upper edge of the X-ray image. Panoramic radiography and computed tomography demonstrated a foreign body in the right sinus. Sinus exploration was performed via a surgical procedure conducted using topical anesthesia. The root apices of tooth 14 were resected, and foreign substance was removed. The practitioner did not correctly recognize a complication that occurred during endodontic treatment, which resulted in extrusion of endodontic material beyond the root apices of tooth 14. This case emphasizes the potential impact that an involved maxillary sinus may have on endodontic therapy. Detailed diagnostic identification based on the medical interview, physical and histopathological examinations, and diagnostic imaging allowed rapid surgical intervention and prevented local and general complications. It is important to realize that the range of the periapical X-ray projection is not always sufficient.

Assessing the Penetrating Abilities of Experimental Preparation with Dental Infiltrant Features Using Optical Microscope: Preliminary Study.

BACKGROUND: The aim of the infiltration technique is to penetrate demineralized enamel with a low viscosity resin. Icon® (DMG) is the first ever and so far the only dental infiltrant. Bacteriostaticity is one of the properties that should be inherent in dental infiltrants, but Icon lacks this feature. OBJECTIVES: The aim of the preliminary study was to properly choose a dye which would allow us to assess the penetrating abilities of our own, experimental preparation with features of a dental infiltrant with bacteriostatic properties and to compare using an optical microscope the depth of infiltration of the designed experimental preparation with the infiltrant available on the market. MATERIAL AND METHODS: The preparation is supposed to infiltrate decalcified human enamel and be assessed with an optical microscope. Eosin, neutral fuchsine and methylene blue were added to experimental preparation with dental infiltrant features and to Icon® (DMG) in order to assess the depth of penetration of the experimental solution into the decalcified layers of enamel. RESULTS: The experimental solution mixes well with eosin, neutral fuchsine, and methylene blue. CONCLUSIONS: During the preliminary study, the authors concluded that the experimental solution mixes well with methylene blue, neutral fuchsine, and eosin. An addition of eosin to a preparation which infiltrates inner, demineralized enamel layers, facilitates the assessment of such a preparation with an optical microscope. A designed experimental solution with the main ingredients, i.e., 2-hydroxyethyl methacrylate (HEMA) and tetraethylene glycol dimethacrylate (TEGDMA) with a ratio of 75% to 25% penetrates the demineralized (decalcified) inner parts of the enamel and polymerizes when exposed to light. In order to assess the infiltration of the experimental solution into the demineralized enamel layers, it is required to improve the measurement techniques that utilize optical microscopy.

Using an Electron Scanning Microscope to Assess the Penetrating Abilities of an Experimental Preparation with Features of a Dental Infiltrant: Preliminary Study.

BACKGROUND: The resin infiltration technique is one of the micro-invasive methods whose aim is the penetration of demineralized enamel with a low viscosity resin. This technique allows the dentist to avoid the application of mechanical means of treatment. OBJECTIVES: The objective of this preliminary study was to attempt to determine the possibilities of using an electron microscope to assess the penetrating abilities of an experimental preparation with features of a dental infiltrant and to compare the depth of infiltration of the designed experimental preparation with an infiltrant available on the market. MATERIAL AND METHODS: A bioactive methacrylate monomer based on PMMAn with built-in metronidazole was synthesized. The commercially available Icon solution (with contrast agent YbF3) and the experimental solution were applied to the relevant parts of teeth. The dissected sections along the long tooth axis and polished surfaces were then examined with use of an electron scanning microscope. RESULTS: The backscattered electron technique gives much better results than the secondary electron method as it makes it possible to localize even very small YbF3 particles. CONCLUSIONS: The authors concluded that the backscattered electron technique gives much better results than the secondary electron method as it makes it possible to localize even very small particles of the contrast agent. In order to prevent blockage of decalcified enamel tissue by ytterbium trifluoride (YbF3) grains, a nanoparticle form of that compound should be used (that is, particles with sizes in the range of 10-9 m).

Effects of Brazilian Propolis on Dental Plaque and Gingiva in Patients with Oral Cleft Malformation Treated with Multibracket and Removable Appliances: A Comparative Study.

Orthodontic appliances modify the local environment of the oral cavity, increase the accumulation of dental plaque, and affect the condition of the gingiva. The aim of this study is assessment of Brazilian propolis toothpaste's effect on plaque index (PLI) and gingival index (GI) in patients with CL/CLP treated using orthodontic appliances in the 35-day study period. The study population included 96 patients of an Orthodontic Outpatient Clinic, ACSiMS in Bytom. All the patients participated in the active phase of orthodontic treatment using buccal multibracket appliances or removable appliances. During the first examination, each patient was randomly qualified to the propolis group or control group. A statistically significant decrease in GI and PLI in the entire propolis group (P < 0.01) was shown during repeated examination. Insignificant change in GI was in the entire control group during the repeated examination compared to the baseline. Similar result was obtained in patients treated with multibracket and removable appliances. The orthodontic appliance type did not affect the final dental plaque amount and gingival condition in patients using the propolis toothpaste. These results may be clinically useful to improve prevention and control oral infectious diseases during orthodontic treatment patients with oral cleft.

The Influence of Ethanolic Extract of Brazilian Green Propolis Gel on Hygiene and Oral Microbiota in Patients after Mandible Fractures.

Maintenance of proper oral hygiene by dental plaque elimination is one of the most important factors affecting the healing process in postoperative oral wounds. Propolis is a substance produced by bees. Ethanolic extract of propolis has bactericidal, fungicidal, anti-inflammatory, and antioxidative properties. Moreover, it can scavenge free radicals. The purpose of this paper is to demonstrate the efficacy of a gel containing 3% of ethanolic extract of Brazilian green propolis (EEP-B) when used for maintaining oral hygiene in patients with postoperative oral mucosal wounds. The hygiene was assessed using API, OHI, and SBI followed by microbiological examinations. The patients were divided into two groups. Group 1 consisted of those who used a gel containing EEP-B for oral hygiene, and group 2 consisted of those who used a gel without EEP-B. Although improved oral hygiene was noted in both groups, the improvement was markedly greater in the group using gel containing EEP-B. Summing up the results of microbiological examinations, EEP-B has beneficial effect on mouth microflora in postoperative period. Propolis preparations used for oral hygiene allow eliminating microorganisms of pathogenic character and physiological flora microorganisms considered as being opportunistic, with no harmful influence on physiological microflora in oral ecosystem.

Concept of experimental preparation for treating dentin hypersensitivity.

BACKGROUND: Dentinal hypersensitivity (DH) is a diagnostic and therapeutic problem that is now appearing more frequently in modern dentistry. The aim of this work was to elaborate formulation of a new, original desensitizing preparation with prolonged action based on the knowledge of similar commercializations and to compare their performance in vitro. METHODOLOGY: The analyses were performed with the aid of NMR spectroscopy. The experimental and commercial preparations were examined in vitro after thermocycling on human teeth by optical microscopy. The presence of the material on tooth tissue, its ability to penetrate into the tooth structure and its layer thickness were subjected to statistical analysis. RESULTS: A detailed knowledge on composition of commercial material was achieved from spectroscopic measurements. A new adhesive monomer was synthesized and incorporated into an experimental desensitizing formulation. The new monomer appeared to have comparable performance to the commercial one when regarding the affinity to tooth tissue and resistance to thermocycling. CONCLUSIONS: The experimental formulation comprising a new adhesive monomer seems to be promising and could be applied in dental practice providing that biocompatibility is satisfactory.

Attempt to assess the infiltration of enamel made with experimental preparation using a scanning electron microscope.

INTRODUCTION: The resin infiltration technique, a minimally invasive method, involves the saturation, strengthening, and stabilization of demineralized enamel by a mixture of polymer resins without the need to use rotary tools or the risk of losing healthy tooth structures. AIM OF THE STUDY: To design and synthesize an experimental infiltrant with potential bacteriostatic properties.To compare the depth of infiltration of the designed experimental preparation with the infiltrant available in the market using a scanning electron microscope. MATERIAL AND METHODS: Composition of the experimental infiltrant was established after analysis of 1H NMR spectra of the commercially available compounds that can penetrate pores of demineralized enamel. As the infiltrant should have bacteriostatic features by definition, an addition of 1% of monomer containing metronidazole was made. Thirty extracted human teeth were soaked in an acidic solution, which was to provide appropriate conditions for demineralization of enamel. Afterward, each tooth was divided along the coronal-root axis into two zones. One zone had experimental preparation applied to it (the test group), while the other had commercially available Icon (the control group). The teeth were dissected along the long axis and described above underwent initial observation with use of a Hitachi S-4200 scanning electron microscope. RESULTS: It was found that all samples contained only oxygen and carbon, regardless of the concentration of additions introduced into them. The occurrence of carbon is partially because it is a component of the preparation in question and partially because of sputtering of the sample with it. Hydrogen is also a component of the preparation, as a result of its phase composition; however, it cannot be detected by the EDS method. CONCLUSIONS: SEM, in combination with X-ray microanalysis, does not allow one to explicitly assess the depth of penetration of infiltration preparations into enamel.In order to assess the depth of penetration of infiltration preparations with use of X-ray microanalysis, it is recommended to introduce a contrast agent that is approved for use in dental materials, such as ytterbium III fluoride.