In vitro effect of beer, red and white wine on the morphology and surface roughness of human enamel.

BACKGROUND: Beer, red and white wine are acidic drinks whose frequent consumption can increase the risk of dental erosion. OBJECTIVES: To establish the effect of beer, red and white wine on the morphology and surface roughness (SR) of human enamel using different exposure times in a cyclic deand remineralization model in vitro. MATERIAL AND METHODS: The experiment included 33 surgically extracted impacted human third molars from patients aged 18-25 years. Enamel samples obtained by cutting crowns (n = 132) were submitted to alternate cycles of demineralization in (1) beer, (2) red wine, (3) white wine, (PC) positive control (orange juice), and remineralization in artificial saliva, which also represented a medium for negative control (NC). The experiment included cycles with different exposure times in alcoholic beverages and orange juice of 15, 30 and 60 min. Thus, 12 groups were formed (for each drink and each exposure time) containing 10 samples each, while the NC group consisted of 12 samples. Experiments were repeated 3x/day for 10 days. Enamel surface alterations were determined by stylus profilometry (average surface roughness (Ra)) and scanning electron microscopy (SEM). The Shapiro-Wilk test, independent samples Kruskal-Wallis test and multiple comparisons (all pairwise) were performed. RESULTS: With increasing exposure time, there was a positive correlation with Ra for white wineand orange juice-immersed samples (60 min compared to 15 min), which was also observed using SEM. There was no significant difference in the Ra between the other experimental samples for the same exposure time. CONCLUSIONS: This study confirms a certain erosive potential of beer, red and white wine, and a significant relationship with pH, titratable acidity (TA) and SR, but not with the exposure time for all tested alcoholic beverages. Moreover, differences among the ultrastructural patterns caused by alcoholic beverages over the enamel surface were observed.

Effects of Autoclave Sterilization on Cyclic Fatigue Resistance in 5 Types of Rotary Endodontic Instruments: An In Vitro Study.

BACKGROUND Rotary endodontic instruments are increasingly used in root canal treatment and have replaced stainless steel manual files. Cyclic fatigue is the cyclic loading of stress to produce deformation or fracture. This study aimed to evaluate and compare the effects of autoclave sterilization on cyclic fatigue in 5 types of rotary endodontic instruments. MATERIAL AND METHODS ProTaper Universal, BioRace, ProTaper Next, Twisted File, and HyFlex CM instruments were included in this study. Each type included 96 instruments, divided into 4 groups according to the number of sterilization cycles (0, 1, 3, 5). After sterilization, each group of instruments was divided into 2 subgroups and tested for cyclic fatigue in 2 simulated canals (45 degrees both and 2 radii, 2 mm and 5 mm). The number of cycles to failure (NCF) was calculated, and statistical analyses were carried out using the t test, Mann-Whitney U test, and ANOVA, followed by the Tukey post hoc test (p<0.05). Fracture surfaces were analyzed using scanning electron microscopy (SEM). RESULTS Within the group of non-sterilized instruments, ProTaper Universal showed significantly lower resistance to cyclic fatigue compared to the other types of instruments (p<0.001). After repeated sterilization, a significantly higher mean of NCF was observed for BioRace (p<0.001), ProTaper Next (p<0.001), Twisted File (p<0.001), and HyFlex CM (p<0.001) compared to ProTaper Universal. The resistance of HyFlex CM was significantly higher compared to the other types of instruments (p<0.001). CONCLUSIONS The findings from this study showed that autoclave sterilization of newer rotary endodontic instruments could increase resistance to cyclic fatigue.

Determining the Impact of the COVID-19 Pandemic on Dental Care in the Serbian Adult Population: An Online Questionnaire-Based Study.

BACKGROUND Emergence of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2 virus) could lead to an increase in dental anxiety, avoidance of dental visits, and general neglect of oral health. This online questionnaire-based study conducted in April and May of 2021 in Serbia aimed to determine the impact of the coronavirus disease 2019 (COVID-19) pandemic on dental care. MATERIAL AND METHODS The study included 2060 adult citizens of the Republic of Serbia who participated in an anonymous online questionnaire based on a 5-point Likert scale. Data were collected on dental care routine prior to and during the pandemic, and the fear of negative consequences for oral health. The results were statistically analyzed using descriptive statistics, Pearson's correlation coefficient, ANOVA, and the paired t test. RESULTS Approximately one-fifth of the respondents postponed dental visits during the pandemic. Concern about postponing dental treatment was expressed by more than one-half of the respondents (57.1%), while 21.4% thought that they were already experiencing the consequences. Avoidance of preventive examinations and improvement of oral hygiene are more common among the elderly compared to younger respondents (P=.000). CONCLUSIONS The COVID-19 pandemic did not significantly affect the habit of avoiding dental interventions due to fear, but it did lead to part of the population completely avoiding even urgent dental interventions during the peak of the pandemic, and opting for tooth extraction rather than treatment. The strongest impact on dental care in the pandemic was among people over 64 years old.

COVID-19: Another Cause of Dental Anxiety?

BACKGROUND Fear has always been closely linked to dentistry but it could be intensified by the objective risks imposed by the pandemic. The objective of this study was to determine the profile of the frightened dental patient during the COVID-19 pandemic and determine measures taken by dentists to reduce fear and increase security among their patients. MATERIAL AND METHODS An anonymous online survey was conducted between March 15 and April 15, 2021. The respondents were 2060 adult citizens of the Republic of Serbia. In addition to demographic data, data related to the COVID-19 pandemic, dental fear, and attitudes and fear of dental interventions during the ongoing pandemic were compiled. The data were analyzed using descriptive statistics: the chi-square test and Pearson's coefficient. RESULTS Seventy percent of the respondents felt some level of fear of the ongoing pandemic, 50% felt fear of going to a dentist during the pandemic, 20% considered a dental office a hotspot for the transmission of SARS-CoV-2, and 43% would visit their dentist only in the case of emergency. CONCLUSIONS The COVID-19 pandemic has affected the attitudes and behavior of people pertaining to visits to dental offices. Identifying frightened patients and their opinions and fears at this challenging time would make it easier for dentists to include protocols in their everyday practice to increase a sense of security among their patients, such as implementing preventive measures in front of the patients, ensuring an empty waiting room, and providing telephone consultations.

Curcumin nanoliposomes mitigate wound tissue inflammatory response caused by tooth extraction

Abstract Curcumin is a plant-derived compound with polypharmacological properties that are hampered by its poor solubility, fast degradation, etc. Wound closure complications that follow tooth extraction are numerous, and relatively frequently additional treatment is needed to prevent unwanted process chronification. The present study aims to compare the effects of free and the nanoliposome-encapsulated curcumin on tooth extraction wound closure. The experiments were performed on Wistar rats where both forms of curcumin were applied topically on a tooth extraction wound for seven days. Changes in tissue oxidative stress (malondialdehyde and oxidized proteins concentrations, and catalase activity) and inflammation (nitric oxide levels and myeloperoxidase activity) related parameters were studied three and seven days following the tooth extraction. Also, the extent of pathohistological changes and osteopontin immunohistochemical expression were studied. The obtained results indicate that both forms of curcumin prevent an increase in oxidative stress and inflammation-related parameters in the studied samples at 3-and 7-day time points. Additionally, we found that curcumin diminished tissue inflammatory response and osteopontin expression, while at the same time it caused faster granulation tissue maturation. The encapsulation of curcumin in nanoliposomes proved to be better in improving the extraction wound healing process than the free curcumin, giving this formulation a potential in the pharmaceutical industry.

Oral Health-Related Risk Factors Among Students in Southeast Serbia.

BACKGROUND An association between insufficient or irregular oral hygiene with the occurrence of dental caries, gingival/periodontal diseases, and consequently general diseases has been established. The null hypothesis that there is no difference in the oral health status among students in a preclinical medical program and those who went through a clinical medical program was tested. The main objective of the study was to analyze oral health risk factors (oral hygiene practices, attitudes, and behavior) as well as their impact on oral health by using convenience sampling. MATERIAL AND METHODS We investigated risk factors for oral health conditions by examining oral hygiene practices, attitudes, and behaviors among the students in the medical program of the University of Nis, collecting data using questionnaires. The study included 396 students of medicine, dentistry, pharmacy, and vocational studies. Participants filled out the anonymous questionnaire. RESULTS In both groups, parents were mostly employed, with the representation of employed fathers significantly higher in student group 1 (P<0.05), which is also the only statistically significant difference between the groups. In terms of oral hygiene practices, students were most often trained by parents (68.69%). A very high percentage of students brushed their teeth every day (97.22%), and 54.55% did this twice a day. Of the total number of students, 78.28% thought that it was necessary to use interdental brushes/floss/toothpick. The duration of teeth cleaning was 3 minutes in 39.39%, whereas 55.30% thought that it should be longer than 3 minutes. The most common brushing movements were combined movements and were used by 60.35% of all students. Of all students, 253 (63.89%) never smoked, 182 (49.96%) regularly went to the dentist, and 141 (35.61%) visited the dentist 6 months ago. The majority of students, 265 (66.92%), obtained the greatest amount of information about oral and tooth care from their dentist, which was the case in both age groups. CONCLUSIONS This study highlights oral health risk factors among students at the University of Nis. It is essential to determine their oral health knowledge, as it is of great significance both to patients and to students. Also, these students will be the major providers of health services and will be responsible for public oral health promotion. It could help in reformation of the oral health education program. The results of this research indicate that it is necessary to educate preclinical students to solve oral health issues.

Influence of etching mode and composite resin type on bond strength to dentin using universal adhesive system.

Adhesive bond strength at the composite/dentin interface is influenced by various factors, including the etching mode and composite resin type. The purpose of this study was to evaluate the influence of the total-etch and self-etch mode on the microtensile bond strength (µTBS) of conventional and bulk-fill composite to dentin, using the universal adhesive system. Sixty non-carious human teeth were sectioned parallel to their longitudinal axis, using a low-speed diamond saw to obtain a flat dentin surface. According to the etching technique and composite resin type used, teeth were randomly divided into four different groups (n = 15): TC (total-etch/conventional composite), TB (total-etch/bulk-fill composite), SC (self-etch/conventional composite), and SB (self-etch/bulk-fill composite). Cylindric composite build-ups were made with 3M Filtek Z250 and 3M Filtek Bulkfill Posterior, using a plastic mold, 4 mm in diameter and 4 mm in height. The specimens were subjected to the µTBS test in a universal testing machine and failure force was recorded. Failure modes were determined using stereoscopic and scanning electron microscopy. Data were analyzed using the two-way ANOVA and Student's t test. The µTBS was significantly affected by the etching technique. A significant statistical difference was determined between total-etch and self-etch groups, irrespective of the composite resin type used. Higher bond strength was obtained in total-etch groups. The µTBS was not affected by the composite resin type. No significant statistical difference was determined between the conventional and bulk-fill groups, irrespective of the etching-mode.

Ultrastructural changes in the cemento-enamel junction caused by acidic beverages: An in vitro study.

The present in vitro study was aimed at evaluating the morphological changes in the cemento-enamel junction (CEJ) after exposure to acidic beverages using the scanning electron microscopy (SEM). The initial pH and titratable acidity (TA) was analyzed from follow groups: (I) Coca cola, (II) orange juice, (III) Cedevita, (IV) Red Bull, (V) Somersby cider, and (VI) white wine. The CEJ samples (n = 64), obtained from unerupted third molars, were allocated to one control (artificial saliva, n = 16) and six experimental groups (n = 8). The experimental samples were immersed in beverages (50 ml) for 15 min, three times daily, 10 days, and in artificial saliva between immersions. SEM analysis was performed in a blind manner, according to scoring scale. One-way ANOVA and Tukey's post hoc tests, as well as Kruskal-Wallis and Mann-Whitney U test used for statistical analysis. The pH values of the acidic beverages ranged from 2.65 (Coca cola) to 3.73 (orange juice), and TA ranged from 1.90 ml (Coca cola) to 5.70 ml (orange juice) of NaOH to reach pH 7.0. The SEM analysis indicated statistically significant differences between the control samples and those immersed in acidic beverages. The Groups IV, I, and II, showed the highest CEJ damage grade while those of the Group VI were the lowest. All the tested acidic beverages caused morphological changes in the CEJ with a smaller or larger exposure of dentine surface, and were not always related to the pH or TA of acidic beverages.

Effects of coenzyme Q10 encapsulated in nanoliposomes on wound healing processes after tooth extraction.

BACKGROUND/PURPOSE: Tooth extraction is often followed by a number of different complications that demand additional treatment. In order to accelerate healing processes and decrease the complication occurrence various agents, growth factors, natural and synthetic antioxidants (e.g coenzyme Q10-CoQ10), are applied. Due to the partially known health-promoting effects of CoQ10 we decided to assess potential of it's encapsulated in nanoliposomes form on wound healing process following tooth extraction. MATERIALS AND METHODS: Effects of free and encapsulated form of CoQ10 on wound healing processes after tooth extraction in rats, 3 and 7 days following surgical procedure, was studied by means of tissue biochemical (myeloperoxidase activity and nitric oxide (NO) concentrations) and pathohistological analysis. RESULTS: The obtained results indicate that the encapsulated form of CoQ10 compared to control and CoQ10 treated animals statistically significantly decreases inflammatory process estimated through myeloperoxidase activity and NO concentrations, as well as based on histopathological analysis 3 and 7 days following surgery. CONCLUSION: The results of this study unequivocally prove that the encapsulation of CoQ10 in nanoliposomes enhances CoQ10 activity by accelerating wound healing process after tooth extraction.

Marginal adaptation of composite resins under two adhesive techniques.

In the present research, different adhesive techniques were used to set up fillings with composite resins. After the application of etch and rinse or self etch adhesive technique, marginal adaptation of composite fillings was estimated by the length of margins without gaps, and by the microretention of resin in enamel and dentin. The study material consisted of 40 extracted teeth. Twenty Class V cavities were treated with 35% phosphorous acid and restored after rinsing by Adper Single Bond 2 and Filtek Ultimate-ASB/FU 3M ESPE composite system. The remaining 20 cavities were restored by Adper Easy One-AEO/FU 3M ESPE composite system. Marginal adaptation of composite fillings was examined using a scanning electron microscope (SEM). The etch and rinse adhesive technique showed a significantly higher percentage of margin length without gaps (in enamel: 92.5%, in dentin: 57.3%), compared with the self-etch technique with lower percentage of margin length without gaps, in enamel 70.4% (p < .001), and in dentin-22.6% (p < .05). In the first technique, microretention was composed of adhesive and hybrid layers as well as resin tugs in interprismatic spaces of enamel, while the dentin microretention was composed of adhesive and hybrid layers with resin tugs in dentin canals. In the second technique, resin tugs were rarely seen and a microgap was dominant along the border of restoration margins. The SEM analysis showed a better marginal adaptation of composite resin to enamel and dentin with better microretention when the etch and rinse adhesive procedure was applied.

Prevalence of Human Cytomegalovirus and Epstein-Barr Virus in Chronic Periapical Lesions.

OBJECTIVE: The aim of this study was to investigate the presence of human cytomegalovirus (HCMV) and Epstein-Barr virus (EBV) in the tissue of chronic periapical lesions, and to compare the results in relation to the symptoms of patients and the size of the lesion. METHODS: Periapical lesions analyzed in the study were collected from the roots of the teeth indicated for extraction. Samples were divided according to the symptoms into groups of symptomatic and asymptomatic, and according the size into groups of small and large lesions. Polymerase chain reaction was used to detect HCMV and EBV. The amplification was performed in a DNA Thermal Cycler (Hybaid). RESULTS: Symptomatic lesions were 7.68 times more likely to be infected with HCMV than asymptomatic lesions (p < 0.001). Large symptomatic lesions were 73.50 times more likely to harbor HCMV than small symptomatic lesions (p < 0.001). Large symptomatic lesions were 7.64 times more likely to be infected with EBV than small symptomatic lesions (p = 0.05). Large symptomatic lesions were 5.38 times more likely to harbor dual HCMV/EBV infection than small symptomatic lesions (p = 0.115). CONCLUSION: Detection of HCMV and EBV in the samples of periapical lesions suggests an important role of herpesviruses in periapical tissue destruction.

Erosive Effect of Different Soft Drinks on Enamel Surface in vitro: Application of Stylus Profilometry.

OBJECTIVE: To assess the erosive potential of various soft drinks by measuring initial pH and titratable acidity (TA) and to evaluate enamel surface roughness using different exposure times. MATERIALS AND METHODS: The initial pH of the soft drinks (group 1: Coca-Cola; group 2: orange juice; group 3: Cedevita; group 4: Guarana, and group 5: strawberry yoghurt) was measured using a pH meter, and TA was measured by titration with NaOH. Enamel samples (n = 96), cut from unerupted human third molars, were randomly assigned to 6 groups: experimental (groups 1-5) and control (filtered saliva). The samples were exposed to 50 ml of soft drinks for 15, 30 and 60 min, 3 times daily, during 10 days. Between immersions, the samples were kept in filtered saliva. Enamel surface roughness was measured by diamond stylus profilometer using the following roughness parameters: Ra, Rq, Rz, and Ry. Data were analyzed by one-way ANOVA, Tukey's post hoc and Student-Newman-Keuls post hoc tests. RESULTS: The pH values of the soft drinks ranged from 2.52 (Guarana) to 4.21 (strawberry yoghurt). Orange juice had the highest TA, requiring 5.70 ml of NaOH to reach pH 7.0, whereas Coca-Cola required only 1.87 ml. Roughness parameters indicated that Coca-Cola had the strongest erosion potential during the 15 min of exposure, while Coca-Cola and orange juice were similar during 30- and 60-min exposures. There were no significant differences related to all exposure times between Guarana and Cedevita. Strawberry yoghurt did not erode the enamel surface regardless of the exposure time. CONCLUSION: All of the tested soft drinks except yoghurt were erosive. Erosion of the enamel surfaces exposed to Coca-Cola, orange juice, Cedevita, and Guarana was directly proportional to the exposure time.

[Scanning electron microscopy analysis of marginal adaptation of composite resines to enamel after using of standard and gradual photopolimerization].

INTRODUCTION: Bonding between composite and hard dental tissue is most commonly assessed by measuring bonding strength or absence of marginal gap along the restoration interface. Marginal index (MI) is a significant indicator of the efficiency of the bond between material and dental tissue because it also shows the values of width and length of marginal gap. OBJECTIVE: The aim of this investigation was to estimate quantitative and qualitative features of the bond between composite resin and enamel and to determine the values of MI in enamel after application of two techniques of photopolymerization with two composite systems. METHODS: Forty Class V cavities on extracted teeth were prepared and restored for scanning electron microscope (SEM) analysis of composite bonding to enamel. Adhesion to enamel was achieved by Adper Single Bond 2 - ASB (3M ESPE), or by Adper Easy One--AEO (3M ESPE). Photopolymerization of Filtek Ultimate--FU (3M ESPE) was performed using constant halogen light (HIP) or soft start program (SOF). RESULTS: Quantitative and qualitative analysis, showed better mikromorphological bonding with SOF photopolymerization and ASB/FU composite system. Differences in MI between different photopolymerization techniques (HIP: 0.6707; SOF: 0.2395) were statistically significant (p < 0.001), as well as differences between the composite systems (ASB/FU: 0.0470; AEO/ FU: 0.8651) (p < 0.001) by two-way ANOVA test. CONCLUSION: Better marginal adaptation of composite to enamel was obtained with SOF photopolymerization in both composite systems.

[Analysis of antimicrobial effect of MTAD solution in infected root canal system using PCR technique].

INTRODUCTION: Clinically acceptable antiseptic should possess organolithic-mineralolithic properties and antimicrobial efficacy, and should be non-toxic. OBJECTIVE: The aim of the paper was to assess the presence of genomes of the most common microorganisms (Porphyromonas gingivalis, Agregatibacter actinomycetemcomitans, Tanerella forsythensis, Prevotella intermedia, Treponema denticola and Enterococcus faecalis) in infected tooth root canals before and after rinsing with solution of doxycycline, citric acid and detergent Tween-80 (MTAD) in patients with clinically diagnosed primary apex periodontitis. METHODS: The content of primarily infected canals before and after using the MTAD solution was used as a biological material in which the presence of microorganisms DNA was proved. For the detection of bacterial genome the multiplex PCR technique was applied. RESULTS: The percentage of positive samples before canal treatment was 100%. In infected root canals E. faecalis was most dominant (37%). In a relatively high percentage we detected P. intermedia (25%), A. actinomycetemcomitans (20%), T. denticola (17%), T. forsythensis (15%) and P. gingivalis (10%). After rinsing the canal system using MTAD solution, there was a statistically significant decrease in E. faecalis (12%), P. intermedia (0%), T forsythensis (0%) and P. gingivalis (0%). The presence of other bacteria was also diminished but not statistically significantly. CONCLUSION: With the application of multiplex PCR technique which provided a simultaneous amplification of various genomic sequences, using several pairs of primers, the most dominant in infected root canals were E. faecalis. P. intermedia, A. actinomycetemcomitans, T. denticola, T. forsythensis and P. gingivalis. After mechanic treatment and irrigation of root canals with MTAD solution, P. intermedia, P. gingivalis and T forsythensis were not found. The presence of E. faecalis, A. actinomycetemcomitans and T. denticola was diminished, however, not statistically significantly.

Ultrastructural changes in the cemento-enamel junction after vital tooth bleaching with fluoride and fluoride-free agents - a pilot study.

BACKGROUND: The impact of bleaching on the cemento-enamel junction (CEJ) is not well known. Due to frequent sensitivity of the cervical region of teeth after the vital bleaching, the aim of the present study was to evaluate the morphological features of the CEJ of human teeth after application of fluoridated and fluoride-free bleaching agents, as well as post-bleaching fluoridation treatment, by scanning electron microscopy (SEM) analysis. MATERIAL/METHODS: Thirty-five extracted permanent human teeth were longitudinally cut, yielding 70 specimens. Thirty specimens were randomly divided into the 3 experimental groups, and 20 specimens, were used as (2) control groups, each: negative (untreated) control group; positive control group treated with 35% hydrogen peroxide; experimental group 1, bleaching with 10% carbamide peroxide (CP); experimental group 2, treatment with a mixture of 10% CP and fluoride; and experimental group 3, treatment with 10% CP and 2% sodium fluoride gel applied 30 minutes after bleaching. Experimental groups were treated 8 h per day for 14 days. The samples were examined by SEM. RESULTS: The bleaching materials tested caused morphological changes to the surface of the CEJ. There was a statistically significant difference between experimental groups (Kruskal Wallis Test chi-square=11,668; p<0.005). Mean value of experimental group 2 scores showed statistically significant difference from groups 1 and 3. CONCLUSIONS: Bleaching gel with fluorides does not significantly change morphological appearance of the CEJ and represents a better choice than the hard tissue fluoridation process after bleaching.

[Incidence of lip and palate clefts in children in Nis from 1990 to 2007].

INTRODUCTION: Cleft lip and palate is a complex congenital anomaly of the orofacial system in children. OBJECTIVE: The aim of this study was to determine the incidence of live-born children with cleft lip and/or palate compared to the total number of children born in the period from January 1, 1990 to December 31, 2007. METHODS: Epidemiological investigation was based on the records of live-born children at the Hospital of Gynaecology and Obstetrics of the Clinical Centre Nis. The study included 61,116 live-born children, i.e. 56,905 full-term babies. RESULTS: The total number of registered clefts during the investigation period was 43 (22 boys and 21 girls). The most frequent were the secondary palate clefts (44.2%); combined cleft were present in 34.9%, while primary palate clefts were reported in 20.9%. In respect to the season and order of birth, there was no statistically significant difference in the frequency of the primary, secondary and complete palate clefts. The age of mothers was not identified as a risk factor for the occurrence of cleft lip and palate. CONCLUSION: In the studied period, 43 children were born with the cleft lip and/or palate, equally in boys as in girls. The secondary palate clefts were most frequent. The season and order of birth had no statistical influence on the occurrence of this anomaly.

[Tooth macromorphological and ultrastructural analysis of osteological material from the medieval locality of St. Panteleimon Church in Nis].

INTRODUCTION: Analysis of macromorphological and ultrastructural tooth characteristics of osteological material from the medieval site of St. Pantaleimon Church in Nis provides us with insight on the life, nutrition and habits of medieval population, as well as the structure and composition of their teeth. OBJECTIVE: The aim of this research, based on the tooth inspection of skeletal remains from the medieval site of St. Pantaleimon Church in Nis, was to analyze macromorphological characteristics, ultrastructure of the dental tissue of maxillary and mandibular molars, canines and incisors, as well as their chemical composition. METHODS: Macromorphological and ultrastructural analysis of the dental tissue of osteological material dating from the 12th century included 1312 teeth with advanced abrasion. Macromorphological changes were detected by using a dental mirror, probe and radiography. After irrigation, the teeth were prepared using the standard procedure and analyzed by scanning electronic microscopy (JEOL-JSM-5300). Chemical analysis was done by expanded downscaling (EDS) method for Mg, P, Ca. RESULTS: The analysis detected second degree abrasions of all teeth in individuals aged 20-25 years. Third and fourth degree abrasions of teeth were detected in individuals aged over 40 years. Ultrastructural analysis showed a complete obliteration of dentin tubules and pulp of the lower incisors, the apposition of intratubular dentin inside the tubules, as well as extensive deformity and loss of dentin structure on molars with preserved pulp volume and nerve fiber calcification. The calcification of nerve fibers showed that the formation of intratubular dentin was proportional with the biological potential of pulp and the degree of abrasion, and inversely proportional with the size of dentin surface. Chemical analysis showed that in the analyzed teeth Ca composition was slightly lower than that in the control group, P composition was almost identical, while Mg composition was multiply increased in comparison to the control group consisting of today's persons of matching age and examined teeth as the medieval individuals. CONCLUSION: Different ultrastructural tooth characteristics as a part of the complex masticatory system of the medieval man are the result of individual and the whole community adaptation to actual living conditions. Nerve fibers calcification of the pulp can explain the absence of pain despite the high level of dental abrasion.

[SEM investigation of composite restoration adaptation to enamel after use of total etch and self etch adhesive system].

INTRODUCTION: Quality and durability of enamel/composite interface essentially depend on an adhesive restorative system. OBJECTIVE: The aim of this study was to evaluate the quality of marginal adaptation of composite adhesive systems to enamel by scanning electron microscopy (SEM), and to analyse the morphology of the enamel surface along margins of composite restorations, following exposure to cariogenic solution. METHODS: The study material included 56 extracted human third molars. Class V cavities were prepared with margins at enamel. Cavities were restored with Single Bond/Z250 and Single Bond/Filtek flow, using the total etch adhesive system, and Prompt-L-Pop/Z250 and Prompt-L-Pop/Filtek flow, using the self etch adhesive system. After the restorative procedure, the restorations were submitted to demineralization during 7 and 28 days. Samples were stored in a cariogenic solution (lactic acid, pH 4.5; 0.1 M) at 37 degrees C or in deionized water (the control group). The margins of restorations and perimarginal enamel were examined by scanning electron microscope (SEM). The gap formations around restoration were measured on cervical, occlusal and approximate margins. RESULTS: The usage of the total etch adhesive system showed statistically significant lower marginal gap width around composite restoration, compared with the self etch system (p < 0.01). The SEM examination also showed perimarginal enamel zones presenting several signs of demineralization and erosion (alteration of rods, porosities) after acting of a cariogenic solution, in both adhesive methods. Less alteration was found on the enamel surfaces not included in the perimarginal zone. CONCLUSION: Treating the cavity with 35% phosphoric acid in the total etch system significantly improved the adaptation of the composite resins to enamel, compared with the self etch treatment. Stronger demineralization of the perimarginal enamel in a cariogenic solution was observed around all restorations in both adhesive systems.

[Efficiency of final irrigation of root canal in removal of smear layer].

INTRODUCTION: A smear layer forms on the root canal walls as the consequence of root instrumentation. The smear layer formed in such a way considerably influences the quality of root obturation and endodontic treatment outcome. OBJECTIVE: The aim of this study was to ultrastructurally analyse the surface of intracanal dentine after removal of the smear layer by the solution of doxycycline, citric acid and detergent Tween-80 (MTAD). METHODS: The study involved 60 single-rooted, extracted, human teeth divided into four groups. All samples were instrumented by a step-back technique and manual K-files, and rinsed during instrumentation by 2% CHX and H2O2. The first group of samples was exclusively rinsed by CHX and H2O2; in the second group, besides using CHX and H2O2, MTAD solution was used for the final irrigation. The samples which were rinsed by distilled water (+ control) and the samples rinsed by 5.25% NaOCI and 17% Na EDTA (-control) served as control groups. All samples were observed under the scanning electronic microscope JEOL-JSM-5300. The coronary, middle and apex thirds of the radix region were analysed. RESULTS: The obtained results of the SEM analysis showed that the application of 2% chlorhexidine and hydrogen peroxide did not give clear dentine walls, and the smear layer could not be removed completely. The application of the same combination (CHX and H2O2), added by the final MTAD irrigation solution, led to the efficient removal of the smear layer, while the morphological structure of dentine surface remained unchanged. Statistical analysis showed that canal walls in the experimental group with MTAD as the final irrigation were significantly clearer compared to the control group (p < 0.001). CONCLUSION: Based on the obtained results, it can be concluded that MTAD is an efficient solution for the final irrigation of the canal system.

[Tooth pathology analysis of osteological material from the Medieval locality of Saint Pantelejmon church in Nis].

INTRODUCTION: Medieval necropolis at the porch of St. Panteleimon church in Nis, from 12th century represents a typical Serbian necropolis, which has its analogies in several areas in Serbia. Preservation of the skeletal remains belongs to category of good and medium preservation. OBJECTIVE: The aim of the work was to study the skeletal remains for the prevalence of tooth caries, localization of caries lesions, presence of abrasion, supragingival tartar and resorption of alveolar bone as the indicator of periodontal disease. METHOD: The analyses included 42 skeletal remains. The anthropological analyses involved paleopathological findings on 954 teeth of 22 men and 20 women. The pathological changes of teeth were determined by inspection, dental probe, dental mirror and x-ray examination. Epidemiological research was done using average caries index. RESULTS: The antropological tooth pathology research of osteological material from the medieval localization of St. Pantaleimon Church in Nis showed the presence of caries in 7.86% cases, 9.93% women and 6.07% men. In 76% caries were localized on the approximal surfaces of teeth. Abrasion of the second and third degree was registered on the side and front teeth with transformation of contact points into contact surfaces and the creation of approximal, interstitial, scolded surfaces. A large quantity of supragingival tartar was found in all individuals aged over 25 years. Expressed alveolar bone resorption is the indicator of generalized periodontal disease. CONCLUSION: The prevalence of caries in the studied medieval population from the 12th century was sporadic, with localization on secondary predilection places. The abrasion of the second and third degree was present, and the resorption of the alveolar bone was registered in all the examined skeletal remains, which was the indicator of spread periodontal disease in this period.