Uticaj bezalkoholnih i alkoholnih pića na humanu gleđ i uloga dentalne pelikule u zaštiti gleđi od erozije: in vitro studija

This research aimed to estimate the erosive potential of 14 beverages – 11 nonalcoholic drinks (five carbonated beverages, two of which were energy drinks), six soft drinks (two types of fruit juice, two sports drinks and two types of tea) and three alcoholic beverages (beer, red wine and white wine) – and to determine the extent to which certain components of the dental pellicle contributed to the protection of the enamel against the erosive damage. The erosive potential was determined by measuring the pH and titratable acidity (TA). Guarana and Schweppes demonstrated the lowest initial pH values, whereas the orange juice and the aronia juice had the highest ones. Coca-Cola had the lowest value of the TA while the orange juice had the highest TA value. The roughness of the eroded enamel surfaces was examined by the analysis of the roughness parameters on the enamel samples dipped in the beverages three times a day for 15, 30 and 60 minutes throughout the period of 10 days. The most intensive enamel erosion was observed in the following samples: those immersed in Red Bull for 15 minutes, the ones immersed in the orange juice for 30 minutes and the samples immersed in Coca-Cola for 60 minutes. Green and black tea did not cause any erosive changes. The enamel surface morphology was analysed by means of the scanning electron microscope (SEM) according to the score-scale from 0 to 3. The samples dipped in Red Bull had the highest average grade, while those immersed in green tea had the lowest one. The SEM changes on the enamel surface were generally accompanied by the roughness parameters, but the profilometric parameters and morphological changes were not always consistent with the pH and TA, which implied more complex mechanisms involved in the development of erosion. Four types of saliva were prepared to examine the protection of enamel from erosion: the human stimulated saliva (collected from healthy donors), artificial saliva and two types of dialysed saliva, one of which contained salivary proteins and ions while the other one had only salivary proteins without ions. The enamel samples were first immersed in a particular saliva four times and then in the citric acid for three minutes. After analyzing the roughness parameters obtained by the atomic force microscope (AFM), it was concluded that the pellicle formed from salivary proteins without saliva ions provides the best protection against erosion

Ultrastrukturna analiza neinstrumentisanih površina u kanalu korena posle različitih irigacionih protokola

Introduction During endodontic treatment smaller or larger areas of root canal wall remain non-instrumented. This can affect prognosis of endodontic treatment as some bacteria may be left behind. The purpose of this study was to evaluate the morphology of non-instrumented areas of the root canal wall using scanning-electron-microscopy (SEM) after completed instrumentation and various irrigation regiments. Materials and Methods Eighteen single-rooted extracted teeth were divided into the six groups. One tooth in each group represented a control sample. In all samples only one half of the canal was instrumented using ISO 40 hand files. Control samples were subjected to an irrigation protocols without instrumentation. Irrigants used were physiological saline, 3% sodium hypochlorite and 15% of ethylene-diamine-tetra-acetate. Irrigation protocol included using each of these irrigants alone, or a combination of NaOCl and EDTA, as well as their combination with final irrigation using NaOCl or chlorhexidine. Then after, roots were sectioned longitudinally and prepared for SEM. Results Saline irrigation left pulpal debris on uninstrumented areas of the canal wall. Irrigation with 3% NaOCl left behind canal wall with different forms of calcospherites. However, after EDTA irrigation dentin appeared as an undulating surface with open tubules without a smear layer. The combination of NaOCl and EDTA showed remnants of calcospherites and open slightly widened dentinal tubules. Final irrigation with NaOCl on the uninstrumented areas showed enlarged dentinal tubules along with dentinal erosion, while after final irrigation with CHX clean dentin and open dentinal tubules without smear layer were noted. Conclusion From the morphological point of view, the most favorable effect of irrigation on both uninstrumented and uninstrumented canal walls was achieved after irrigation with NaOCl and EDTA or NaOCl, EDTA and chlorhexidine as the final irrigant.Uvod Tokom endodontske terapije manje ili veće površine kanala korena zuba ostaju neinstrumentisane i mogu sadržavati bakterije, što može dovesti do neuspešnog ishoda. Cilj rada je bio da se skening-elekron-mikroskopskom (SEM) analizom proceni morfologija neistrumentisanih delova zidova kanala posle instrumentacije i primene različitih irigacionih protokola. Materijal i metode rada Osamnaest jednokorenih ekstrahovanih zuba je podeljeno u šest grupa. Jedan zub iz svake grupe je predstavljao kontrolni uzorak. Eksperimentalni uzorci su preparisani do instrumenta veličine ISO40. Kod svakog zuba je instrumentisana samo jedna polovina kanala. Kontrolni uzorci su podvrgnuti samo irigacionim protokolima bez preparacije. Osim fiziološkog rastvora, 3% natrijum-hipohlorita i 15% etilen-diamin-tetra-acetata, koji su primenjeni samostalno, eksperimentalni uzorci su irigirani i sa kombinacijom NaOCl i EDTA, kao i sa kombinacijom istih iriganasa, pri čemu je kao završni irigans korišćen ili NaOCl ili hlorheksidin. Korenovi su uzdužno presečeni i pripremljeni za SEM. Rezultati Posle irigacije sa fiziološkim rastvorom u neinstrumentisanim delovima kanala uočen je dentin pokriven debrisom, posle irigacije sa NaOCl dentin sa različitim oblicima kalcisferita. Posle irigacije sa EDTA uočena je talasasta površina dentinskog zida sa otvorenim tubulima bez razmaznog sloja. Irigacija kombinacijom NaOCl i EDTA je pokazala ostatke kalcisferita i otvorene, blago proširene dentinske tubule. Završno ispiranje sa NaOCl na neinstrumentisanim delovima dentina pokazuje proširene dentinske tubule i eroziju dentina, a završno ispiranje sa CHX čist dentin i otvorene dentinske tubule bez razmaznog sloja. Zaključak Sa morfološkog aspekta, najpovoljniji efekat irigacije (i kod instrumentisanih i kod neinstrumentisanih delova kanala) ustanovljen je posle irigacionih protokola sa: NaOCl i EDTA i NaOCl, EDTA i hlorheksidinom kao završnim irigansom

The effect of zinc oxide based sealer on bone defects healing

Introduction Obturation as the final phase of endodontic treatment aims to provide complete hermetic filling along the entire length of the canal system from the coronal opening to the apical end. The aim of this study was to evaluate histological response of bone tissue on the implantation of zinc oxide based material in artificially prepared defect in the mandible of rats. Material and method For the experiment, sixteen male Wistar rats were used. Using sterile steel burs a defect was made in mandible, between the midline and mental foramen. Zinc oxide based sealer was implanted in the defects of experimental group while the defects of control group healed spontaneously. One half of animals in both groups were sacrificed after thirty days, and the second half after ninety days. Microscopic preparations consisted of the defect with surrounding bone and after processing were analyzed using light microscopy. Results The thirtieth day after implantation of the material, fibrovascular connective tissue was noted, with scant chronic inflammatory cell infiltrate. Away from the experimentally made defect, in the depth of the bone, lamellar bone with well-formed larger osteons was noted as well as enlarged Volkmann and Haversian canals. Ninety days after implantation of the material, there was no restitutio ad integrum, but intense focal remodelling of bone tissue was noted. Conclusion Endomethasone N slowed down bone tissue healing process by showing the signs of prolonged inflammation in bone tissue in which it has been implanted. Extension of the healing process is reflected in the slow replacement of fibrovascular connective tissue with newly formed bone tissue

The concentration of tumor necrosis factor alpha in periapical lesions

Introduction. The balance between proinflammatory and anti-inflammatory cytokines plays an important role in the pathogenesis of chronic periapical lesions. The aim of this study was to determine the concentration of TNF-α in tissue homogenates of periapical lesions and analyze its levels in relation to the symptomatology and the size of lesions. Materials and Methods. 93 samples of chronic periapical lesions were obtained after extraction of teeth. Samples were classified according to the clinical presentation as symptomatic and asymptomatic, and according to the size as large and small. The concentration of TNF-α was analyzed using ELISA. Results. The results showed increased production of TNF-α in symptomatic lesions compared to asymptomatic. Higher concentration of TNF-α was demonstrated in large lesions compared to small. Large symptomatic lesions showed greater concentration of TNF-α compared to small symptomatic lesions, while bigger asymptomatic lesions demonstrated higher amount of the cytokines compared to small asymptomatic lesions. Conclusion. Higher concentration of TNF-α in large symptomatic lesions indicates that TNF-α is an important factor responsible for the progression of lesions

Ultrastrukturna analiza površine endodontskih instrumenata nakon potapanja u rastvore za irigaciju

Introduction Separation (fracture) of endodontic instruments in the root canal during chemomechanical instrumentation is a complication that can compromise the final outcome of endodontic treatment. One of the most common factors that cause fatigue of endodontic instruments and consequent fracture is surface corrosion. The aim of this study was to investigate the ultrastructure of surface corrosion of endodontic instruments made of stainless steel and nickel-titanium after immersion in the most commonly used root canal irrigants. Material and Methods The study included 48 nickel-titanium and stainless steel endodontic hand files. All instruments were immersed in 5.25% sodium hypochlorite, 0.2% CHX and 17% EDTA. Surface corrosion was analyzed using a scanning electron microscope (SEM). Results Nickel-titanium instruments showed significantly higher susceptibility to corrosion after immersion in 5.25% sodium hypochlorite compared to stainless steel instruments (p lt 0,001). After immersion in 0.2% CHX corrosion damage was observed on both nickel-titanium and stainless steel instruments but the difference was not statistically significant (p=0.096). No corrosion was observed in both types of instruments after immersion in 17% EDTA. Conclusion The use of 5.25% NaOCl and 0.2% CHX as root canal irrigating solutions can cause serious corrosion changes on the surface of nickel-titanium and stainless steel endodontic instruments.Uvod Fraktura endodontskih instrumenata u kanalu korena tokom hemomehaničke preparacije je značajna komplikacija koja može ugroziti konačan ishod endodontskog lečenja. Jedan od važnih faktora koji izazivaju zamor materijala endodontskog instrumenta je površinska korozija. Cilj ovog rada je bio da se ispita ultrastruktura površine endodontskih instrumenata od nerđajućeg čelika i nikl-titanijuma nakon potapanja u najčešće upotrebljavane rastvore za irigaciju kanala korena zuba. Materijal i metode rada U istraživanju je korišćeno 48 instrumenata od nikl-titanijuma i nerđajućeg čelika. Testiranje osetljivosti na koroziju je izvršeno potapanjem u rastvore NaOCl od 5,25%, CHX od 0,2% i EDTA od 17%. Analiza korozivnih oštećenja je urađena pomoću skening elektronskog mikroskopa (SEM) na različitim uveličanjima. Rezultati Instrumenti od nikl-titanijuma su pokazali statistički značajno veću osetljivost na koroziju nakon potapanja u 5,25% NaOCl u poređenju sa instrumentima od nerđajućeg čelika (p lt 0,001). Nakon potapanja u 0,2% CHX uočeno je korozivno oštećenje instrumenata od nikl-titanijuma i nerđajućeg čelika, ali razlika nije bila statistički značajna. Korozija nakon potapanja u 17% EDTA nije uočena ni kod jedne vrste endodontskih instrumenata. Zaključak Primena 5,25% NaOCl i 0,2% CHX kao rastvora za irigaciju kanala korena može izazvati ozbiljne korozivne promene na površini instrumenata od nikl-titanijuma i nerđajućeg čelika

Ultrastrukturna ispitivanja površine endodontskih instrumenata od nerđajućeg čelika

Introduction Although many studies have reported various advantages of nickel-titanium endodontic instruments, the use of stainless steel endodontic files still presents a standard in everyday practice. The aim of this study was to evaluate ultrastructure of the surface of stainless steel endodontic instruments before and after their use. Material and Methods Fourteen sets of non-used stainless steel endodontic reamers and files were included in the study. Each set of instruments was used one, three or six times in simulated clinical conditions on extracted maxillary premolars. After their use the instruments were subjected to cleaning and sterilization procedures. Ultrastructure of the surface of instruments was observed under scanning electron microscope (SEM). Surface analysis was performed based on the number of uses and size of instruments. The following characteristics were analyzed: defects of instrument flutes, defects of cutting edges and instrument deformations. Results SEM analysis showed defects on the surface of non-used instruments as a result of the manufacturing process. Surface defects, defects of cutting edges as well as flutes deformations were observed after a single use and were more often noticed in small sized instruments. After three uses, flutes deformations were observed in all small sized instruments and some of the medium size. After six uses all groups of instruments showed defects of cutting edges. Conclusion Non-used stainless steel endodontic instruments showed surface defects created by the manufacturing process. Defects of cutting edges and flutes can be observed after a single use. To minimize complications and mistakes during clinical preparation it is recommended to limit the number of instrument uses.Uvod Iako brojne studije ističu prednost korišćenja instrumenata od nikl-titanijuma zbog njihovih prednosti, primena endodontskih instrumenata od nerđajućeg čelika i dalje je standard u svakodnevnoj praksi. Cilj ovog rada je bio da se provere ultrastrukturne odlike površine radnog dela endodontskih instrumenata od nerđajućeg čelika pre i posle njihove upotrebe. Materijal i metode rada U istraživanju je korišćeno 14 setova novih ručnih proširivača i turpija od nerđajućeg čelika. Instrumenti svakog seta su korišćeni jednom, tri i šest puta za preparaciju kanala u simuliranim kliničkim uslovima na ekstrahovanim gornjim premolarima. Nakon svake upotrebe instrumenti su očišćeni i sterilizovani. Površina instrumenata je posmatrana i analizirana na skening-elektronskom mikroskopu (SEM). Analiza ultrastrukture instrumenata vršena je u pogledu broja upotreba i veličine. Kada su u pitanju ultrastrukturne promene na instrumentima, analizirani su oštećenja površine i sečiva i deformacije instrumenata. Rezultati SEM analiza je pokazala da i kod novih instrumenata postoje oštećenja koja su verovatno posledica proizvodnog procesa. Nakon prve upotrebe javljala su se oštećenja površine, sečivnih ivica, kao i deformacije navoja, i to češće kod manjih veličina. Nakon tri upotrebe deformiteti navoja su se javili kod svih instrumenata malih veličina i kod pojedinih instrumenata srednje velicine. Nakon šeste upotrebe dominirala su oštećenja u vidu tupljenja i zalamanja sečivnih ivica, koja su bila jednako zastupljena u svim grupama instrumenata. Zaključak Novi endodontski instrumenti od nerđajućegčelika imaju na svojoj površini oštećenja koja potiču od procesa proizvodnje, a deformacije instrumenata i oštećenja seciva se javljaju već posle prve kliničke upotrebe. Da bi se sprečile komplikacije i greške u kliničkom radu, preporuka je da broj upotreba endodontskih instrumenata bude ograničen

Ultrastructural analysis of uninstrumented root canal areas following various irrigation regimens

Introduction During endodontic treatment smaller or larger areas of root canal wall remain non-instrumented. This can affect prognosis of endodontic treatment as some bacteria may be left behind. The purpose of this study was to evaluate the morphology of non-instrumented areas of the root canal wall using scanning-electron-microscopy (SEM) after completed instrumentation and various irrigation regiments. Materials and Methods Eighteen single-rooted extracted teeth were divided into the six groups. One tooth in each group represented a control sample. In all samples only one half of the canal was instrumented using ISO 40 hand files. Control samples were subjected to an irrigation protocols without instrumentation. Irrigants used were physiological saline, 3% sodium hypochlorite and 15% of ethylene-diamine-tetra-acetate. Irrigation protocol included using each of these irrigants alone, or a combination of NaOCl and EDTA, as well as their combination with final irrigation using NaOCl or chlorhexidine. Then after, roots were sectioned longitudinally and prepared for SEM. Results Saline irrigation left pulpal debris on uninstrumented areas of the canal wall. Irrigation with 3% NaOCl left behind canal wall with different forms of calcospherites. However, after EDTA irrigation dentin appeared as an undulating surface with open tubules without a smear layer. The combination of NaOCl and EDTA showed remnants of calcospherites and open slightly widened dentinal tubules. Final irrigation with NaOCl on the uninstrumented areas showed enlarged dentinal tubules along with dentinal erosion, while after final irrigation with CHX clean dentin and open dentinal tubules without smear layer were noted. Conclusion From the morphological point of view, the most favorable effect of irrigation on both uninstrumented and uninstrumented canal walls was achieved after irrigation with NaOCl and EDTA or NaOCl, EDTA and chlorhexidine as the final irrigant

Ultrastructural analysis of the surface of endodontic instruments after immersion in irrigating solutions

Introduction Separation (fracture) of endodontic instruments in the root canal during chemomechanical instrumentation is a complication that can compromise the final outcome of endodontic treatment. One of the most common factors that cause fatigue of endodontic instruments and consequent fracture is surface corrosion. The aim of this study was to investigate the ultrastructure of surface corrosion of endodontic instruments made of stainless steel and nickel-titanium after immersion in the most commonly used root canal irrigants. Material and Methods The study included 48 nickel-titanium and stainless steel endodontic hand files. All instruments were immersed in 5.25% sodium hypochlorite, 0.2% CHX and 17% EDTA. Surface corrosion was analyzed using a scanning electron microscope (SEM). Results Nickel-titanium instruments showed significantly higher susceptibility to corrosion after immersion in 5.25% sodium hypochlorite compared to stainless steel instruments (p<0,001). After immersion in 0.2% CHX corrosion damage was observed on both nickel-titanium and stainless steel instruments but the difference was not statistically significant (p=0.096). No corrosion was observed in both types of instruments after immersion in 17% EDTA. Conclusion The use of 5.25% NaOCl and 0.2% CHX as root canal irrigating solutions can cause serious corrosion changes on the surface of nickel-titanium and stainless steel endodontic instruments

An influence of finishing procedures and protective coating on the ultrastructure of conventional and hybrid glass ionomer cement restorations

Introduction In addition to the advantages of glass ionomer cements that have led to their wide application, hybrid glass ionomer cements have been developed to overcome the shortcomings in mechanical resistance. The aim of the study was to perform an ultrastructural analysis of restorations made from conventional and hybrid glass ionomer cements after recommended finishing procedures and application of a protective coating. Materials and Methods This study analyzed 30 samples of conventional glass ionomer cement Fuji IX™ and 30 samples of hybrid glass ionomer cement EQUIA Forte HT Fil™. The samples were prepared in cylindrical molds and divided into the three groups. The first group of samples, after adaptation, was left untreated and served as a control group. The second group consisted of samples that were finished with a cylindrical diamond bur with water cooling. The samples in the third group were finished and protected with appropriate coatings (G-COAT PLUS™ and EQUIA Forte Coat™). The samples were analyzed using scanning electron microscopy. Results The finishing procedures of Fuji IX™ samples significantly reduced crack width (t = 3.42, p < 0.005; Z = 3.25, p = 0.001). Similarly, the crack width in EQUIA Forte HT Fil™ samples was also significantly smaller in treated samples (t = 4.78, p < 0.001; Z = 4.28, p < 0.001). Ultrastructural analysis of both materials showed the complete absence of cracks in finished samples protected by coatings. Conclusion Finishing of conventional and hybrid glass ionomer cements results in a reduction in the number of cracks as well as a decrease in their widths, and the protective coatings completely cover remaining cracks

Ispitivanje koncentracije faktora nekroze tumora alfa u tkivnim homogenatima periapeksnih lezija

Introduction The balance between proinflammatory and anti-inflammatory cytokines plays an important role in the pathogenesis of chronic periapical lesions. The aim of this study was to determine the concentration of TNF-α in tissue homogenates of periapical lesions and analyze its levels in relation to the symptomatology and the size of lesions. Materials and Methods 93 samples of chronic periapical lesions were obtained after extraction of teeth. Samples were classified according to the clinical presentation as symptomatic and asymptomatic, and according to the size as large and small. The concentration of TNF-α was analyzed using ELISA. Results The results showed increased production of TNF-α in symptomatic lesions compared to asymptomatic. Higher concentration of TNF-α was demonstrated in large lesions compared to small. Large symptomatic lesions showed greater concentration of TNF-α compared to small symptomatic lesions, while bigger asymptomatic lesions demonstrated higher amount of the cytokines compared to small asymptomatic lesions. Conclusion Higher concentration of TNF-α in large symptomatic lesions indicates that TNF-α is an important factor responsible for the progression of lesions.Uvod Balans između proinflamatornih i antiinflamatornih citokina igra važnu ulogu u patogenezi hroničnih periapeksnih lezija. Cilj ove studije je bio da se odredi koncentracija faktora nekroze tumora alfa (TNF-α) u homogenatima tkiva periapeksnih lezija i rezultati analiziraju u pogledu simptomatologije tih lezija kod pacijenata, odnosno veličine lezije. Materijal i metode rada Ispitana su 93 uzorka hroničnih periapeksnih lezija dobijenih nakon ekstrakcije zuba. Uzorci lezija su, prema simptomatologiji pacijenata, podeljeni na simptomatske i asimptomatske, a prema veličini na velike i male. Koncentracija TNF-α u uzorku ispitivana je pomoću testa ELISA. Rezultati Kod klinički simptomatskih lezija uočeno je povećano stvaranje TNF-α u odnosu na asimptomatske. Veća koncentracija TNF-α je dokazana i u velikim lezijama u odnosu na male. Velike simptomatske lezije su pokazale veću koncentraciju TNF-α u odnosu na male simptomatske lezije, dok su velike asimptomatske lezije imale veću količinu ovog citokina u odnosu na male asimptomatske lezije. Zaključak Veća koncentracija TNF-α u velikim i u lezijama s pojačanim kliničkim simptomima pokazuje da je TNF-α važan faktor odgovoran za napredovanje lezije