Analysis of the Activity and Expression of Cyclooxygenases COX1 and COX2 in THP-1 Monocytes and Macrophages Cultured with BiodentineTM Silicate Cement

Biodentine^TM is a material based on hydrated calcium silicate with odontotropic properties. However, from the clinician’s perspective, every material used to fill a tooth—even those showing the optimal biochemical parameters—is in fact a foreign body introduced to the organism of the host. Therefore, apart from the chemical parameters of such materials, equally important is the so-called biocompatibility of such materials. The aim of the study was to investigate whether Biodentine^TM, used in the regeneration of the pulp-dentine complex, may affect the expression of the enzymes cyclooxygenase 1 (COX1) and cyclooxygenase 2 (COX2) in THP-1 monocytes/macrophages and the amount of prostanoids synthesized by these enzymes-precursors of biologically active prostanoids such as prostaglandin E2 (PGE2) and thromboxane (TXB2) which are mediators of inflammation. An original aspect of this research is the use of the THP-1 monocyte/macrophage cell model and the use of biomaterial in direct contact with cells. In this way we tried to reflect the clinical conditions of regenerative pulp and periodontal tissue treatment using Biodentine^TM. The results of our study showed a lack of macrophage activation (measured by flow cytometry) and a lack of stimulation of the expression of the studied cyclooxygenase enzymes (measured by Western blotting and fluorescent microscopy), as well as a lack of increase in the concentration (measured by ELISA method) of their inflammatory mediators (PGE2 and TXB2) in vitro incubated with Biodentine^TM.

Pulp sensibility to electric stimuli in the Caucasian population

The aim of the study was to determine electric sensibility of the pulp in the Caucasian population depending on tooth morphotype, age and sex. Dental pulp sensibility was determined in 279 patients (2640 teeth). The study group consisted of 226 patients (1296 teeth), 110 men and 116 women aged 55-101. The control group consisted of 53 patients (1344 teeth), 23 men and 30 women aged 20-30. A statistically significant lower sensory threshold and increased pulp sensibility in the study group were noted. These affected the lower incisors, the second upper premolars and the first and second upper molar. The differences in the pulp sensibility were found in the region of maxillary central incisors, maxillary premolars, mandibular lateral incisors and mandibular premolars. The pulp sensibility threshold was lower for the aforementioned groups of teeth in the study group. The correlation between sensibility of the pulp and sex was not confirmed.

An Alternative Prosthodontic Management of Maxillary Dentoalveolar Defect in a Patient With Cleft Palate and Lip: Case Report

Cleft palate/lip is a frequently occurring congenital anomaly; one in every 800 births results in such a problem. Different treatment options are available for replacing missing soft and hard tissues, including removable dental prostheses, fixed dental prostheses (FDPs), and implant prostheses. In the literature, according to different authors, there are different option standard for prosthetic treatment of cleft palate/lip. Some authors report that removable prosthesis is the choice in such cases, some of them regard conventional tooth-supported FDPs as a standard of care. In this case report, the prosthetic treatment of congenital cleft palate/lip was described. Upon the choice of the patient and patient's agreement, the direct construction Fibre-reinforced composite (FRC) adhesive bridge with pink composite gingival epithesis was performed.

Analysis of Base Monomer Elution from 3 Flowable Bulk-Fill Composite Resins Using High Performance Liquid Chromatography (HPLC)

Background

The aim of this study was to evaluate the elution of BisGMA, UDMA, TEGDMA, and HEMA monomers from flowable bulk fill composite resins with different resin matrix compositions, polymerized in 4-mm-thick layers, into 3 elution media.

Material/Methods

Three bulk-fill (SDR^® (SDR), X-tra base (XB) and BEAUTIFIL-Bulk Flowable (BF)) resin-composites were tested. Cylindrical samples were immersed in 100% ethanol, 75% ethanol, and distilled water. The concentrations of the monomers were measured using the HLPC method (Agilent Technologies 1200 Series) after 1 and 24 h, as well as after 3, 7, 14, and 21 days.

Results

After polymerization of the tested resins, there was elution of the BisGMA, UDMA, TEGDMA, and HEMA monomers from the SDR and BF composites, but none of the tested monomers could be detected eluting from XB. The highest penetrations of the polymerized SDR and BF composites were observed in the 100% ethanol solution. This extraction medium eluted the highest amounts of free monomers. Some eluted monomers were not described in the composites Material Safety Data Sheets.

Conclusions

The elution of the residual monomers depended on the resin composition and the materials filler/resin matrix ratio. In composite materials, toxicity assessment should be carried out, and should consider both the material composition as given by the manufacturer, and also the residual monomers that elute from the polymerized material. The elution concentration and time of monomers from composites depended on the solvent used. The highest penetrations of the polymerized SDR and BF composites were observed in the 100% ethanol solution, and this extraction medium eluted the highest amounts of free monomers. The 75% ethanol was a more aggressive medium than water in terms of monomer elution from bulk fill composites.

Direct Resin Composite Restoration of Maxillary Central Incisors with Fractured Tooth Fragment Reattachment: Case Report

This article presents a clinical protocol to reconstruct two accidentally damaged maxillary central incisors using composite resin material and a fractured tooth component. A patient was referred to the clinic with fracture of the two maxillary central incisors. Clinical examination revealed that both teeth were fractured in the middle third of the crown and that the fractures involved enamel and dentin with no pulp exposure. The patient had also suffered a lower lip laceration. When the lip was evaluated, a fractured fragment of the maxillary right central incisor was found inside the wound. The missing part of the tooth was replaced via adhesive attachment. Due to the damage of the fractured part of the maxillary left central incisor, direct composite restoration of this tooth was performed. With the advent of adhesive dentistry, the process of fragment reattachment has become simplified and more reliable. This procedure provides improved function, is faster to perform, and provides long-lasting effects, indicating that reattachment of a coronal fragment is a realistic alternative to placement of conventional resin composite restorations.

The functionality of masticatory apparatus and the sense of depression in patients over 55 years of age living in a family environment and social care centres

OBJECTIVES

The aim of this study was to determine the relationship between the masticatory apparatus functionality and a sense of depression in patients over 55 years of age living in a family environment and the Social Care Centres (SCC).

METHODS

Shortened version of the Geriatric Depression Scale (GDS) was used to assess the wellbeing of patients and their state/sense of depression. The clinical evaluation of masticatory function was performed during one appointment in the natural light. The clinical criterion for the retention of masticatory function, adopted by the World Health Organization was a contact between at least 20 opposing teeth, natural or artificial.

RESULTS

Among patients with a low number of GDS points (0-5), statistically significantly higher proportion of people living in family houses (69.4%) maintained functionality of masticatory apparatus than of people living in SCC (23.5%). In contrast, among patients with a higher number of GDS points (6-15), statistically significantly higher proportion of patients living in SCC (70.8%) did not maintain functionality of masticatory apparatus than of those living in family houses (41.7%).

CONCLUSIONS

Patients with a sense of depression living in Social Care Centres were more likely to report lack of functionality of masticatory apparatus than patients with a sense of depression living in family houses. The presence of a growing sense of depression significantly affected a lower rate of preserved functionality of masticatory apparatus or vice versa.

[Diagnostics of approximal caries - literature review]

The most important issue in modern cariology is the early diagnostics of carious lesions, because only early detected lesions can be treated with as little intervention as possible. This is extremely difficult on approximal surfaces because of their anatomy, late onset of pain, and very few clinical symptoms. Modern diagnostic methods make dentists' everyday work easier, often detecting lesions unseen during visual examination. This work presents a review of the literature on the subject of modern diagnostic methods that can be used to detect approximal caries.

Elution study of unreacted TEGDMA from bulk-fill composite (SDR™ Dentsply) using HPLC

PURPOSE

The study evaluates the dynamics of unreacted TEGDMA monomer elution from new generation of flowable bulk fill composite resin (SDR™ Dentsply).

MATERIAL AND METHODS

Polymerised specimens of SDR™ composite (7mm diameter and 4mm thick) were placed in four solutions: 100% ethanol, 75% ethanol, distilled water and 100% methanol. The concentration of the eluted TEGDMA was measured using the HLPC method after 0.5, 1, 2 and 3h as well as after 1, 3, 7, 14, 21 and 31 days.

RESULTS

During the first 24h of storage in each medium, a significant elution of TEGDMA was observed (100% ethanol - 12.5μg/g, 75% ethanol - 8.4μg/g, distilled water - 5.4μg/g and 100% methanol - 7μg/g). The elution time of the TEGDMA into 100% ethanol, 75% ethanol, distilled water and 100% methanol was 14, 7, 3 and 1 day, respectively. After 31 days, total concentrations of TEGDMA were as follows: 100% ethanol - 16μg/g, 75% ethanol - 9.4μg/g, distilled water - 6μg/g and 100% methanol - 7μg/g.

CONCLUSIONS

The TEGDMA was released from the SDR™ composite into each solution used. The TEGDMA concentration and the time of its elution depend on the type of the solvent. In an aqueous environment, the SDR™ composite exhibits a high chemical stability compared to other solutions. The direct toxicity towards to the dental pulp is established during the first hours after the placement of resin.

Impact of functional appliances on muscle activity: a surface electromyography study in children

Background

Electromyography (EMG) is the most objective tool for assessing changes in the electrical activity of the masticatory muscles.

The purpose of the study was to evaluate the tone of the masseter and anterior temporalis muscles in growing children before and after 6 months of treatment with functional removable orthodontic appliances.

Material/Methods

The sample conisted of 51 patients with a mean age 10.7 years with Class II malocclusion. EMG recordings were performed by using a DAB-Bluetooth instrument (Zebris Medical GmbH, Germany). Recordings were performed in mandibular rest position, during maximum voluntary contraction (MVC), and during maximum effort.

Results

The results of the study indicated that the electrical activity of the muscles in each of the clinical situations was the same in the group of girls and boys. The factor that determined the activity of the muscles was their type. In mandibular rest position and in MVC, the activity of the temporalis muscles was significantly higher that that of the masseter muscels. The maximum effort test indicated a higher fatigue in masseter than in temporalis muscles.

Conclusions

Surface electromyography is a useful tool for monitoring muscle activity. A 6-month period of functional therapy resulted in changes in the activity of the masticatory muscles.

[Remineralizing methods in early caries lesions - review of the literature]

Early diagnosis and treatment of early caries lesions are the basic tenets of minimally invasive dentistry. One of the key elements of a biological approach is the usage of remineralizing agents, which are great alternative to surgical intervention. This article shows a review of the literature concering materials used for the treatment of early caries lesions.

The maintenance of pulp health 17 years after root fracture in a maxillary incisor illustrating the diagnostic benefits of cone bean computed tomography

AIM

To demonstrate the maintenance of pulp health in a tooth with a fractured root without any complications or endodontic treatment and the advantage of cone bean computed tomography (CBCT) compared with traditional radiographs in the diagnosis of root fractures.

SUMMARY

The horizontal fracture of a maxillary central incisor is described that was an incidental finding on a routine radiographic examination 17 years after trauma. The tooth was asymptomatic. Intra-oral radiography revealed a complicated multiple root fracture with separation of the root fragments, which was not confirmed by CBCT. This case report illustrates spontaneous healing of root fracture and the reparative potential in the area of root fracture including preservation of pulp health and also demonstrates that CBCT is a more reliable imaging technique than conventional radiographs regarding root fracture diagnosis.

KEY LEARNING POINTS

The dental pulp is characterized by the ability to heal spontaneously in cases of root fracture. CBCT has advantages in diagnosing root fractures over intra-oral radiographs. CBCT should be employed with caution due to its increased radiation dose compared with periapical radiography.

[THE VITAL PULP THERAPY IN PERMANENT TEETH]

The vitality of dental pulp is essential for long-term tooth survival. The aim of vital pulp therapy is to preserve vital, healthy pulp tissue. This therapy's foundation is the elimination of bacteria from the dentin-pulp complex. The treatment option depends on the cause and extent of mineralised tooth tissue destruction. The outcome of such treatment is determined by accurate assessment of the pulp's status and the dentist's ability to predict the success of the therapy. The aim of this review is to facilitate the dentist in making a proper decision referring to vital pulp therapy in permanent teeth, and to provide an overview of new approaches in such treatment.

Loss of sight caused by calcium hydroxide paste accidentally splashed into the eye during endodontic treatment: case report

Calcium hydroxide, widely used in endodontic treatment, is a strong base that may cause irreversible injury to vital tissue that comes into contact with this substance. We present the first case of a dentist who accidentally splashed endodontic calcium hydroxide into her own eye. After washing with copious amounts of water for several minutes, she was treated in the hospital within 30 minutes of the accident. Because of the burning caused by the base solution, the dentist lost vision in the affected eye. She returned to the hospital several times for treatment of a corneal abscess and corneal fungal infection. She had the keloid that formed between the eyeball and eyelid removed 3 times. Calcium hydroxide can cause blindness when it comes into contact with the eye. Clinicians should take adequate precautions to prevent this serious complication. In case of an accident, it is important to wash the eye efficiently.

The influence of polymorphism of the MUC7 gene on the teeth and dental hygiene of students at a faculty of dentistry in Poland

OBJECTIVE

The aim of the study was to analyze polymorphism of the MUC7 gene and its correlation with the DMFT value and the Plaque Control Record by O'Leary.

MATERIAL/METHODS

The study was carried out on 158 students of a faculty of dentistry in Poland. Students were subjected to a clinical oral examination. The status of caries was determined using the decayed, missing and filled teeth (DMFT) value. The status of dental hygiene was examined by the Plaque Control Record (PCR Plaque Index by O'Leary T, Drake R, Naylor, 1972) index. Sherlock AX, a universal kit for DNA isolation from biological tracks (A&A BIOTECHNOLOGY), was used for DNA isolation. VNTR polymorphism in the MUC7 gene was examined by polymerase chain reaction (PCR).

RESULTS

The prevalence of the MUC7*6/*6 genotype was definitely higher than MUC7*5/*6. The distribution of prevalence of MUC7*6/*6 and MUC7*5/*6 in the control group was similar to another. The distribution of the value of the DMFT index in the group examined with MUC7*6/*6 was similar to the group with MUC7*5/*6. Statistical analysis did not show a significant correlation between genotypes of the MUC7 gene and DMFT and the Plaque Control Record index.

CONCLUSIONS

This study does not show a correlation between the MUC7 genotypes and caries and oral hygiene of students.

Prevalence of dental erosion in adolescent competitive swimmers exposed to gas-chlorinated swimming pool water

Objectives

The purpose of this study was to analyze the prevalence of dental erosion among competitive swimmers of the local swimming club in Szczecin, Poland, who train in closely monitored gas-chlorinated swimming pool water.

Materials and methods

The population for this survey consisted of a group of junior competitive swimmers who had been training for an average of 7 years, a group of senior competitive swimmers who had been training for an average of 10 years, and a group of recreational swimmers. All subjects underwent a clinical dental examination and responded to a questionnaire regarding aspects of dental erosion. In pool water samples, the concentration of calcium, magnesium, phosphate, sodium, and potassium ions and pH were determined. The degree of hydroxyapatite saturation was also calculated.

Results

Dental erosion was found in more than 26 % of the competitive swimmers and 10 % of the recreational swimmers. The lesions in competitive swimmers were on both the labial and palatal surfaces of the anterior teeth, whereas erosions in recreational swimmers developed exclusively on the palatal surfaces. Although the pH of the pool water was neutral, it was undersaturated with respect to hydroxyapatite.

Conclusion

The factors that increase the risk of dental erosion include the duration of swimming and the amount of training. An increased risk of erosion may be related to undersaturation of pool water with hydroxyapatite components.

Clinical relevance

To decrease the risk of erosion in competitive swimmers, the degree of dental hydroxyapatite saturation should be a controlled parameter in pool water.

Loss of sight caused by calcium hydroxide paste accidentally splashed into the eye during endodontic treatment: case report

Calcium hydroxide, widely used in endodontic treatment, is a strong base that may cause irreversible injury to vital tissue that comes into contact with this substance. We present the first case of a dentist who accidentally splashed endodontic calcium hydroxide into her own eye. After washing with copious amounts of water for several minutes, she was treated in the hospital within 30 minutes of the accident. Because of the burning caused by the base solution, the dentist lost vision in the affected eye. She returned to the hospital several times for treatment of a corneal abscess and corneal fungal infection. She had the keloid that formed between the eyeball and eyelid removed 3 times. Calcium hydroxide can cause blindness when it comes into contact with the eye. Clinicians should take adequate precautions to prevent this serious complication. In case of an accident, it is important to wash the eye efficiently.

[Influence of tooth crowding on the prevalence of dental caries. A literature review]

Dental caries is a disease of the mineralized tissues of teeth. It usually has a chronic course and is caused by external factors which can be modified. Current opinions about the contribution of malocclusions to the etiology of dental caries are conflicting. Some researchers believe that malocclusions like crowded teeth cause improper contacts between neighboring teeth and make effective oral hygiene more difficult. The difficulty in cleaning crowded teeth is believed to increase plaque accumulation and consequently predisposes the tooth to the development of dental caries and periodontal disease. Others claim that malocclusion has a minimal influence on the development of dental caries and periodontal disease. Ideal oral hygiene is of basic importance for plaque elimination which is the harmful factor in caries and in this way is decisive for the health of mineral and soft tissues to a much greater extent than lack of malocclusion. However, if a person with malocclusion is more susceptible to dental caries, oral hygiene cannot be the decisive factor.

[The effect of age on the process of healing of chronic periapical inflammation]

INTRODUCTION

The aim of this study was to determine the effect of age on the process of healing of chronic periapical inflammation.

MATERIAL AND METHODS

The study was carried out in 59 patients with accidentally disclosed chronic periapical inflammation and no other pathology. The patients were allocated to two age groups: group I--from 17 to 44 years of age; group II--from 45 to 78 years of age. All teeth with periapical inflammation were endodontically treated. Control radiographs were taken 6 and 12 months later.

RESULTS

Radiographs taken after 6 months disclosed partial or complete restoration of periapical tissues in 79.5% of patients in group I and 65.0% of patients in group II. Radiographs after 12 months showed partial or complete healing in 94.8% of patients in group I and 90.0% of patients in group II.

CONCLUSIONS

The process of healing of chronic periapical inflammation lasted longer in patients aged 45-78 years than in patients aged 17-44 years. The outcome of treatment was similar in both groups.

[Response of dental pulp to self-etching adhesive systems used in indirect capping. A literature review]

OBJECTIVE

To review the literature on dental pulp responses to self-etching adhesive systems used in indirect capping.

MATERIAL AND METHODS

Many studies in vitro and in vivo focused on biocompatibility of the self-etching adhesive system used in deep defects. Clinical and radiographic findings from animal and human studies are compared and discussed.

RESULTS

Self-etching adhesive systems may be useful when applied to dentin. The results in animal studies cannot be extrapolated directly to humans. Many studies in vitro have shown that components of self-etching adhesive systems exhibit cytotoxic effects in contact with cell cultures.

CONCLUSIONS

The reaction of dental pulp to self-etching bonding agents depends on the depth of defect, type of agent, and method of application.

[Biofilm formation on root canal--review]

It seems likely that one of the reasons for failures in the endodontic treatment is the presence of biofilm in root canals. Biofilm bacteria have a slower metabolism and higher resistance and virulence due to phenotypic changes. The occurrence of biofilms has been reported both inside the canal and on the external root surface. The results of many studies suggest that biofilm may be associated with refractory periapical periodontitis and is often caused by the coronal leakage.

[Proceeding with patients having mental impairment and those affected by congenital development anomalies during orthodontic treatment]

The aim of the work was to describe the specificity of proceeding with patients having mental impairment and those affected by congenital development anomalies during orthodontic treatment. At the same time, an attempt has been made at solving some problems concerning the treatment of patients with special needs. Based on available references three model syndromes of congenital development anomalies with coexisting mental impairment have been described: Down, Lejeune and Williams syndromes. It results from the descriptions and discussions included in this work that the possibilities of optimal cooperation and most effective treatment of patients affected by congenital birth defects and by mental impairment are conditioned, among other things, by: good contact between a doctor, a patient and a parent (guardian), availability and application of the best treatment solutions as well as coordinated implementation of a common therapeutic plan by members of an interdisciplinary team in specialized medical health centres.

[Mineral trioxide aggregate in the pulp capping treatment tooth]

INTRODUCTION

Therapeutic procedure for the treatment of tooth pulp exposure or pulp injury is a conservative treatment using direct pulp capping.

MATERIAL AND METHODS

Achievements to date in biological pulp treatment and the case of treatment of tooth pulp injury by odontotropic preparation Mineral Trioxide Aggregate (ProRoot MTA, Dentsply Maillefer, U.S.A.) has been presented in this paper. Applied treatment consisted in total processing of cariotic cavity, covering the place of cavity with compomer Dyract and composite Herculite (SDS, Kerr, U.S.A.) material. Pulp of a treated tooth remained its vitality during control study and pathological changes of pulp and within adjacent periapical tissues were not detected by means of an X-ray photography.

RESULTS

After 12 months of observation a positive therapeutic result of pulp vitality preservation in a tooth was achieved.

[Human salivary mucins--their role and meaning]

PURPOSE

The aim of this work is to present the current views concerning the role and the meaning of human salivary mucins.

MATERIAL AND METHODS

A review of works dealing with basic information regarding mucins, their role and use in the diagnosis of some of the systematic diseases.

RESULTS

Human salivary mucins are glycoproteins secreted through epithelial cells of the salivary glands of the oral cavity. Those molecules should not only be linked with the forming of dental plaque or their function of lining the oral cavity with a protective layer. The so far carried out investigations show that apart from lactoferrin, amylases or peroxidases those salivary proteins can be used in the diagnosis of many disease entities.

[Teeth and periodontium status of moderately mentally retarded children and the health awareness of their parents]

INTRODUCTION

The aim of the study was the evaluation of teeth, parodontium and oral hygiene status in non-institutional moderately mentally retarded people. The aspects of dental prophylaxis and dental care of mentally retarded children as well as their practical introduction by the parents of examined children were assessed.

MATERIAL AND METHODS

41 mentally retarded people aged 15-18 years old were clinically examined to assess their teeth status (DMF), parodontium status (CPI) and oral hygiene (PI). The parents of these children were surveyed by a questionnaire (39 questions).

RESULTS

The results showed a low treatment index, significantly higher number of teeth missing and those to be extracted because of caries. The knowledge of dental prophylaxis and dental treatment aspects of the parents of mentally retarded children did not reveal any significant impact on the teeth and parodontium status as well as oral health of the examined children.

[Dental status in patients with eating disorders]

Anorexia nervosa and bulimia are serious eating disorders on the mental background that affect a significant number of young people. They lead to many complications including the ones within the oral cavity. The most frequent effects concerning tooth hard tissue are dental erosions. Erosions are characterized by the irreversible process of demineralization of the external layers of tissues of the tooth. This paper reviews literature to assess the oral status and dental complications in patients with eating disorders.

[Detection of early fissure caries with clinical, radiologic, and laser fluorescence methods]

PURPOSE

The aim of study was to compare the diagnostic efficacy of the newly introduced DIAGNOdent laser fluorescence with traditional methods for detection of molar caries, namely visual inspection and bitewing radiographs.

MATERIAL AND METHODS

Discolored fissures of 134 permanent molars were studied in 103 patients aged 12-18 years.

RESULTS

The results indicate that visual examination and bitewing radiographs showed very high or high sensitivity and specificity for the detection of early fissure caries. Combination of these two methods decreased the number of false positive and negative results. Diagnostic accuracy of DIAGNOdent was significantly inferior to that of clinical examination or bitewing radiographs.

CONCLUSION

However, the diagnostic accuracy of DIAGNOdent was increased by combining it with one of the two traditional methods studied.

[The effectiveness of some methods in eliminating bacteria from the root canal of a tooth with chronic apical periodontitis]

MATERIAL AND METHODS

[corrected] The study material consisted of 45 teeth with chronic apical periodontitis treated in 37 patients (22 females and 15 males). The aim of the study was to determine the effectiveness of one-visit (group 1, 26 teeth) and two-visit endodontic treatment with iodoform and pulpomixine between visits (group II, 19 teeth) in eliminating bacteria from the root canal.

RESULTS

Microbiological samples were cultured and microorganisms were identified before and after treatment. A rich and varied bacterial flora was found in all samples before treatment. Following treatment, there were 17 (65.4%) bacteria-free root canals and 9 (34.6%) canals with sparse bacterial flora in group I and 15 (78.9%) bacteria-free and 4 (21.1%) bacteria-containing root canals in group II.

CONCLUSION

We conclude that both methods performed similarly and neither method was fully effective in eliminating bacteria from the root canals.

[Concentration of fluoride in mixed saliva of patients with end-stage renal disease undergoing renal replacement therapy]

This study was carried out on 48 patients with ESRD undergoing hemodialysis treatment (29 males and 19 females, mean age 50.8 years) and renal transplantation (15 females and 33 males, mean age 42.2 years). The results were compared with a group of 44 healthy persons (23 females and 21 males, mean age 49.5 years). The aim of our investigation was to examine the content of fluoride in the mixed unstimulated saliva of the patients undergoing renal replacement therapy and in the control group of healthy persons. We studied the influence of hemodialysis on saliva fluoride levels. Saliva samples were collected by the spitting method according to Navazesh. Samples were collected before and after hemodialysis session and once in graft recipients and controls. Fluoride concentrations were determined with an Orion fluoroselective electrode model 96-09. The fluoride level in healthy persons was 4.92 +/- 2.30 micromol/L. Before hemodialysis, the mean fluoride level was 9.63 +/- 3.90 micromol/L and decreased significantly to 7.52 +/- 2.71 micromol/L after hemodialysis (p < 0.0001). Saliva content of fluorides in patients before and after hemodialysis was significantly higher than in healthy subjects and kidney graft recipients (p < 0.0001). There was no significant difference in fluoride concentration between patients after kidney transplantation and controls. The results suggest the need for individual fluoride supplementation in chronically hemodialysed patients.

[Factors that modify de- and remineralization in dental enamel from the aspect of caries susceptibility]

The course of caries depends on an equilibrium between de- and remineralization of enamel. Epidemiologic studies performed during recent years in Poland have demonstrated a high incidence and severity of caries in children and teenagers. Therefore, the actual program of caries prevention covering the whole population of children and teenagers has not performed to the expectations, possibly because the program protocol does not discriminate between children susceptible and resistant to caries. The aims of this work included: 1. Analysis of tooth groups and surfaces as to their susceptibility to caries; 2. Evaluation of the influence of de- and remineralization modifying factors such as: a) dental plaque and sugars, b) caries-causing bacteria, c) enamel resistance to acids, d) biochemical properties of saliva--on the susceptibility to caries; 3. Evaluation of the uptake of fluorides from chewing gum by enamel in relationship to caries susceptibility. An initial clinical examination of permanent teeth was performed in 292 children aged 12 years. Subsequently, two groups were formed: one with 45 children free from caries and another with 77 children at high risk of caries. Control examinations of permanent teeth in both groups were carried out after one and three years from the initial examination. The clinical examination included a check-up of secondary dentition, counting of erupted teeth, sealed teeth, evaluation of oral hygiene status, gingivae, abnormalities in mineralization and measurement of the rate of microdemineralization. The biochemical analysis of saliva was done to measure the content of fluorides, calcium, phosphorus and magnesium, as well as pH. Microsamples of enamel were collected using acid biopsy and the content of calcium and fluorine in the superficial and underlying layer was assayed. The thickness of both layers obtained by biopsy was also measured. Commercial test kits--Dentocult SM and Dentocult LB, served to determine the amount of caries-causing bacteria in saliva. Additionally, the children and their mothers responded to a questionnaire on the diet, previous diseases, therapies with antibiotics and health habits. The results were analysed using Statgraphics software. Differences between means were checked using Student t-test in its classical form or as modified by B. L. Welch. Linear correlation indices were calculated and Spearman rank correlation test was performed. On the basis of the results obtained the following conclusions were drawn: 1. 12-year old children at high risk of caries need intense dental care due to: a) extensive involvement of masticatory surfaces of molar teeth and contact surfaces of premolar teeth, b) treatment inappropriate to actual needs in this group of children. 2. Effective programs to improve the knowledge and health of children at high risk to caries should be introduced due to the following facts: a) oral hygiene was unsatisfactory in the examined children, b) children consumed large quantities of sweets. 3. Disturbances in the mineralization of enamel and the use of antibiotics in childhood were without influence on the susceptibility of teeth to caries. 4. The content of fluorides, calcium and phosphorus in the saliva of children susceptible to caries could have been below the level necessary to maintain an equilibrium between de- and remineralization of enamel. 5. Susceptibility of teeth to caries could be due to differences in the chemical composition and structure of enamel, as it appears from the content of fluorides and calcium, depth of enamel biopsy and uptake of fluorides from chewing gum. 6. Chewing of fluoride-containing gums is a supportive measure in caries prevention, particularly recommended in children at high risk of caries. 7. Caries prevention should be individualized and matched to caries risk.