Aleksandar Mitic

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, Tukeys 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.

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.

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

Summary 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.

Concentration of Transforming Growth Factor-beta 1 in Chronic Periapical Lesions / Ispitivanje koncentracije transformišućeg faktora rasta beta 1 u hroničnim periapeksnim lezijama

Summary Host response to antigen stimulation in chronic inflammatory periapical lesions is mainly controlled by the balance between proinflammatory and anti-inflammatory cytokines. The aim of this study was to determine the concentration of TGF-β1 in the tissue homogenates of periapical lesions and to analyse its level in relation to the symptomatology of the patients and size of the lesions. Ninety three samples of chronic periapical lesions were obtained after extraction of teeth. Samples were divided according to the clinical symptoms as symptomatic and asymptomatic, and according to the size as large and small. The concentration of TGF-β1 was analyzed using ELISA. The results showed increased production of TGF-β1 in symptomatic lesions compared to asymptomatic, but the difference was not statistically significant. Statistically significant difference in TGF-β1 concentrations was observed in large lesions compared to small (p<0,001). It seems that TGF-β1 have a modulating effect on bone tissue resorption activity under the influence of proinflammatory cytokines and can be molecular prognostic marker of periapical lesion healing. Sažetak Balans između proinflamatornih i antiinflamatornih citokina u velikoj meri kontroliše odgovore domaćina na antigenu stimulaciju kod hroničnih inflamatornih periapeksnih lezija. Cilj istraživanja bio je da se odredi koncentracija TGF-β1 u homogenatima tkiva periapeksnih lezija i da se rezultati uporede u odnosu na simptomatologiju pacijenata i veličinu lezije. Ispitivano je 93 uzorka hroničnih periapeksnih lezija dobijenih nakon ekstrakcije zuba. Uzorci lezija su podeljeni prema simptomatologiji pacijenata na simptomatske i asimptomatske, a prema veličini na velike i male. Koncentracija TGF-β1 je ispitivana pomoću ELISA testa, a dobijene vrednosti su analizirane u odnosu na grupe. Rezultati su pokazali povećanu produkciju TGF-β1 u simptomatskim lezijama u odnosu na asimptomatske, međutim, razlika nije bila statistički značajna. Statistički značajna razlika u koncentraciji TGF-β1 uočena je u grupi velikih lezija u poređenju sa malim (p<0,001). Čini se da TGF-β1 ima modulirajući efekat na aktivnost resorpcije koštanog tkiva pod uticajem proinflamatornih citokina i može se smatrati molekularnim prognostičkim markerom zarastanja periapeksnih lezija.

Ultrastructure of adhesive bond of composite to dentin

SUMMARY Ultrastructure of adhesive bond is a significant indicator of the efficiency of the bond between material and dental tissue. Bonding between composite and hard dental tissue is also most commonly assessed by measuring bonding strength or by absence of marginal gap along restoration interface. The aim of this investigation was to estimate ultrastructural features of the bond between composite materials and dentin after using two adhesive techniques. Twenty Class V cavities on extracted teeth were prepared and restored for scanning electron microscope (SEM) analysis of composite bonding to dentin. Adhesion was achieved by Adper Single Bond 2-ASB/3M ESPE or by Adper Easy One-AEO/3M ESPE. Photopolymerization of adhesives and composite material Filtek Ultimate FU/3M ESPE was performed using halogen light (Elipar Highlight 3M ESPE). After vertical sections through crown of teeth and composite restorations, surfaces of sections were treated with 37% phosphoric acid-60s and 2% NaOH-60s to remove the smear layer and obtain a better view of adhesive bond. SEM analysis of adhesive bond showed better micromorphological bonding of composite to dentin after etch and rinse adhesive technique (ASB/FU matherials) than after self-etch technique (AEO/FU materials). In etch and rinse technique, the ultrastructure of adhesive bond to dentin was composed of adhesive and hybrid layers, with resin processes in dentinal canals. In self-etch technique, apart from adhesive and hybrid layers, resin processes were rare or were not observed at all. Better ultastructural bonding of composite restoration to dentin was obtained with etch and rinse adhesive technique. Sažetak Ultrastruktura adhezivne veze je značajan pokazatelj efikasnosti pripoja materijala za zubna tkiva. Kvalitet veze kompozita za tvrda zubna tkiva takođe se procenjuje jačinom vezivanja ili odsustvom marginalne pukotine po obodu restauracija. Cilj ovog rada bio je da se proceni ultrastruktura veze kompozitnih materijala za dentin nakon primene dve adhezivne tehnike. Na ekstrahovanim zubima restaurisano je 20 kaviteta V klase za skenirajuću elektronsku mikroskopsku (SEM) analizu pripoja kompozita za dentin. Adhezija je obezbeđivana primenom Adper Single Bond2- ASB/3M ESPE, odnosno primenom Adper Easy One-AEO/3M ESPE. Svetlosna polimerizacija adheziva i kompozitnog materijala Filtek Ultimate-FU-/3M ESPE vršena je halogenim svetlom (Elipar Highlight 3M ESPE). Nakon vertikalnog presecanja krunica zuba kroz kompozitne restauracije i pripreme površine preseka (30% fosforna kiselina-30s i 2% NaOH-30s), vršena je SEM analiza adhezivne veze. Bolje mikromorfološko vezivanje kompozita za dentin SEM analiza adhezivne veze pokazala je kod adhezivne tehnike sa nagrizanjem i ispiranjem zubnih tkiva (ASB/FU materijali), u odnosu na tehniku samonagrizanja tkiva (AEO/FU materijali). Kod tehnike nagrizanja i ispiranja, ultrastruktura adhezivne veze za dentin sastojala se od hibridnog i adhezivnog sloja, kao i produžetaka smole u dentinskim kanalićima. Kod samonagrizajuće tehnike, pored adhezivnog i hibridnog sloja, retko su viđani ili uopšte nisu postojali produžeci smole u kanalićima. Bolju ultrastrukturu veze kompozita za dentin obezbedila je primena adhezivne tehnike sa nagrizanjem i ispiranjem tkiva.

Interleukin 1-beta analysis in chronically inflamed and healthy human dental pulp

Introduction: Proinflammatory cytokines can act like endogenous pyrogen interleukin 1, interleukin 6 and tumour necrosis factor alpha (IL-1, IL-6, TNF α) which regulate the synthesis of secondary mediators and other pro-inflammatory cytokines through macrophages and mesenchymal cells. They stimulate the acute-phase proteins and attract inflammatory cells. The aim: The aim of this study was to determine the interleukin 1-β (IL-1 β) concentrations in chronically inflamed and healthy dental pulp. Methods: Forty-one pulps, divided into two groups were obtained from the teeth with chronic pulp inflammation. The control group consisted of twelve teeth with healthy pulp. After extirpation, pulp samples were immediately placed in sterile Eppendorf tubes and frozen. After that, homogenisation was performed by Teflon® pestle in ice-cold phosphate buffer solution at pH 7.4 whose volume was adjusted according to the weight of tissue. The supernatant was then frozen at -70°C until the performance of appropriate biochemical analyses. Cytokine IL-1 β value was determined by a commercial enzyme-linked immunosorbent assay (ELISA test). We applied the high sensitivity system technique, which may register low levels of cytokines, ranging from 0.125 to 8.0 pg/ml for IL-1 β. Results: By comparing the mean value of IL-1β (pg/ml), we can see there is a statistically significant difference (p<0.01). The highest value of IL-1 β was in subjects with Pulpitis chronica clausa and was 6.21 with a standard deviation of 2.70. Conclusion: Proinflammatory cytokine IL-1 β is present in detectable quantities in the pulp tissue of all vital pulps.

Effects of coenzyme Q 10 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 its 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.

GINGIVAL INFLAMMATION AS A SIGN OF DIABETIC SYSTEMIC CHRONIC COMPLICATIONS

Introduction: Diabetes mellitus (DM) is a chronic metabolic disorder and the high level of blood glucose has profound effects on various systems of the human body. DM increases the risk of periodontal disease and the severe periodontal disease often coexists in diabetic patients with poor glycemic control. The aim of the study was to analyse periodontal health in patients with diabetes mellitus type 2 related to diabetic complications and glycohemoglobin A1c values. Methodology: One hundred patients with periodontitis and type 2 DM participated in the study. According to the glycohemoglobin A1c value they were divided in 4 groups: group 1 (4%-6% normal), group 2 (6.1%-7% good), group 3 (7.1%-8% moderately poor), group 4 (> 8% poor metabolic control). The presence of chronic systemic microvascular diabetic complications (retinopathy, nephropathy and neuropathy) was recorded and periodontal assessments (Plaque, Gingival, Calculus and Periodontal Disease Index) performed. The results were statistically analysed using MS Office Excel, program SPSS, 15.0 version. Results: Gingival index values depended on the level of HbA1c values and higher values of the Gingival and Periodontal Disease Index were noticed as the value of glycohemoglobin A1c was rising (p<0,001). Gingival index values were higher in diabetics with diabetic chronic microvascular complications (p<0.001). Conclusion: It is observed that pronounced gingival inflammation in diabetics is associated with systemic diabetic complications and poor glycemic control.

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.

The Effect of Polymerization Technique on Marginal Index of Composite Fillings in Dentin

Summary Polymerization contraction of composite resins has been one of the most extensively studied phenomena in dentistry in recent years. Initial polymerization by low intensity light followed by polymerization high intensity light improves marginal adaptation of composite in tooth cavities. A number of studies have verified that less marginal leakage and lower marginal index (MI) exist in relation to standard polymerization (continuous high intensity light). The aim of the study was to quantittively evaluate the bond of composite materials to dentin and determine the MI values in dentin after the application of two techniques of light polymerization in two composite systems. Twenty V class cavities were restored on extracted teeth for scanning electron microscopic (SEM) analysis of composite to dentin junction. Adhesion to dentin was achieved using Adper Single Bond 2-ASB/3MESPE, that is, Adper Easy One-AEO/3MESPE. Light polymerization of composite materials Filtek Ultimate-FU/3MESPE was performed using standard halogen light (HIP) or soft start program (SOF). Marginal index of dentin was determined by measuring the length and width of marginal gap at the junction of composite filling to dentin, using scanning mirographies and Autodesk AutoCAD program. Two-way ANOVA test was used for statistical processing of the obtained results. Differences in MI index between different light polymerization techniques (HIP- 8,18 and SOF-7,12) were not statistically significant (p>0,05), while the differences between composite systems (ASB/FU- 3,67 i AEO/FU- 7,69) were statistically significant (p <0.05). The polymerization technique showed no significant effect on the composite to dentin junction. Lower MI dentin was established in composite system with the application of adhesive etch and rinse procedure in both polymerization techniques.