Analiza ivičnog pripoja kompozitnih smola za gleđ skening-elektronskom mikroskopijom nakon primene standardne i postepene tehnike fotopolimerizacije

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 lt 0.001), as well as differences between the composite systems (ASB/FU: 0.0470; AEO/ FU: 0.8651) (p lt 0.001) by two-way ANOVA test. Conclusion Better marginal adaptation of composite to enamel was obtained with SOF photopolymerization in both composite systems.Uvod Kvalitet veze kompozita za tvrda zubna tkiva se najčešće procenjuje jačinom vezivanja ili izostankom marginalne pukotine po obodu restauracija. Marginalni indeks (MI) je važan pokazatelj efikasnosti pripoja materijala za zubna tkiva jer istovremeno pokazuje vrednosti i širine i dužine marginalne pukotine. Cilj rada Cilj rada je bio da se kvantitativno i kvalitativno proceni veza kompozitnih materijala za gleđ i utvrde vrednosti MI u gleđi nakon primene dve tehnike svetlosne polimerizacije i dva kompozitna sistema. Metode rada Na ekstrahovanim zubima je restaurisano 40 kaviteta pete klase za analizu pripoja kompozita za gleđ skening- elektronskom mikroskopijom (SEM). Adhezija za gleđ je obezbeđivana primenom Adper Single Bond 2 - ASB (3M ESPE), odnosno primenom Adper Easy One - AEO (3M ESPE). Svetlosna polimerizacija kompozitnog materijala (Filtek Ultimate - FU; 3M ESPE) vršena je standardnim halogenim svetlom (HIP) ili tzv. soft start programom (SOF). Rezultati Kvantitativna i kvalitativna analiza je pokazala bolje mikromorfološko vezivanje kompozita za gleđ kod SOF osvetljavanja i ASB/FU kompozitnog sistema. Na osnovu dvosmernog ANOVA testa, razlike u vrednosti MI između različitih svetlosnopolimerizujućih tehnika (HIP: 0,6707 i SOF: 0,2395) bile su statistički značajne (p lt 0,001), kao i razlike između kompozitnih sistema (ASB/FU: 0,0470 i AEO/FU: 0,8651; p lt 0,001). Zaključak Bolji marginalni pripoj kompozita za gleđ obezbeđen je primenom SOF osvetljavanja kod oba kompozitna sistema

Stromal reaction and prognosis in acinic cell carcinoma of the salivary gland

Introduction. Primary acinic cell carcinoma (ACC) is an uncommon malignant neoplasm of the salivary gland (SG), which usually presents as slow growing tumor. Case report. We reported a 69-year-old woman with tumor in the right parotid gland with a 5-year progress. Biopsy sections revealed a hybrid form of ACC with a low- and high-grade component and prominent lymphoid tissue in tumor stroma. Immunohistochemistry was performed to define the molecular profile of this unusual ACC, with special interest for stromal influence on to the proliferative activity of ACC with dedifferentiation. We detected that the level and the type of stromal lymphoid reaction (particularly CD8+/CD4+ ratio) had a significant influence on to Ki-67 index in the high-grade component of ACC, as well as the involvement of the CXCR4 signaling axis in the stromal reaction influence. Conclusion. We suggest that tumor stroma may be a source of potential new tumor biomarkers which can determine the aggressivity of this tumor.[Projekat Ministarstva nauke Republike Srbije, br. 175092

The impact of forced social comparison on adolescents' self-esteem and appearance satisfaction

The impact of forced social comparison on adolescents' self-esteem and appearance satisfaction research, conducted on a sample of 133 high school seniors, consisted of two phases. In phase one, participants were given the Rosenberg Self-Esteem Inventory, Appearance Satisfaction Scale and Appearance Relevance Scale, and in phase two, one month later, they were exposed to photographs of attractive and unattractive individuals. Two groups of boys and girls each assessed attractive or unattractive individuals of their own gender, while two control groups (of both genders) were not exposed to any photographs. Immediately after assessing the photographs, the participants were again given the Rosenberg Self-Esteem Inventory and Appearance Satisfaction Scale. We found that forced social comparison had an impact on self-esteem and a marginally significant effect on appearance satisfaction in the group of participants (of both genders) assessing the photographs of unattractive individuals, while no effects were found in the either the control group or the group assessing the photographs of attractive individuals. We also examined the impact of self-esteem, appearance satisfaction and appearance relevance as moderating variables on the effect size of social comparison and showed that higher pretest self-esteem and appearance relevance and lower appearance satisfaction predict higher posttest self-esteem scores, regardless of the participants' group membership. The group of participants exposed to photographs of unattractive people, however, showed the opposite pattern - those participants who had initially lower self-esteem have increased it more as a result of the experimental exposure

Efekti lasero-terapije na intrakanalni dentin i cementno tkivo apeksa korena zuba

Laser irradiation during root canal treatment is efficient but in order to prevent irreversible thermal damage to dentine, cementum and other periapical structures continuous water cooling is required. The aim of this study was to ultrastructurally analyze the surface of intracanal dentine and cementum at the root apex after Er:YAG laser irradiation with and without sterile saline solution irrigation. The study involved 70 intact maxillary and mandibular single-rooted and tworooted human teeth, divided into two experimental groups and one control group. In all teeth access cavity was created. For root canal irradiation, Er:YAG laser with the wavelength of 2940 nm, energy output of 140 mJ per pulse, pulse duration of 125-160 ms, pulse repetition rate of 10 Hz and power of 15 W was used. Total irradiation time for each root canal was 10 seconds. The ultrastructural analysis of intracanal dentine and the cementum of the root apex was done by using scanning electron microscope (JEOL JSM-5300 Tokyo Japan). Intracanal Er:YAG laser irradiation without water cooling showed melted circumpulpal dentine with large cracks in it, whereas cementum at the root apex was thermally modified in the form of plates and cracks. Intracanal Er:YAG laser irradiation with continuous water cooling resulted in clean intracanal dentine surface without morphological changes of the cementum. The canal system irradiation is acceptable and possible only when using constant water cooling; otherwise, irreversible thermal damage to intracanal dentine and cementum at the root apex occur.Obrada kanala korena zuba laserom je efikasna, ali zahteva obavezno hlađenje vodom kako bi se sprečila ireverzibilna termička oštećenja dentina, cementa i ostalih periapeksnih struktura. Cilj ovog rada bio je da se ultrastrukturno analizira površina intrakanalnog dentina i cementnog tkiva na apeksu korena zuba posle obrade kanala Er:YAG laserom bez irigacije i sa irigacijom sterilnim fiziološkim rastvorom. Korišćeno je 70 intaktnih maksilarnih i mandibularnih jednokorenih i dvokorenih humanih zuba, podeljenih u dve eksperimentalne i jednu kontrolnu grupu. Kod svih zuba je formiran pristupni kavitet. Za obradu kanala korišćen je Er:YAG laser talasne dužine 2940 nm, izlazne energije za impuls 140 mJ; u pulsnom režimu 125-160ms, stopom pulsne repeticije od 10 Hz i energijom od 15 W. Vreme obrade svakog kanala laserom iznosilo je 10 sekundi. Ultrastrukturna analiza intrakanalnog dentina i cementnog tkiva na apeksnom delu korena zuba urađena je na skening elektronskom mikroskopu (JEOL JSM -5300 Tokyo Japan). Intrakanalna obrada Er:YAG laserom bez vodenog hlađenja pokazuje stopljen cirkumpulparni dentin sa velikim pukotinama u dentinu, a cementno tkivo na apeksu je termički modifikovano u vidu ploča i pukotina. Intrakanalna obrada Er:YAG laserom uz kontinuirano vodeno hlađenje daje čistu intrakanalnu dentinsku površinu bez morfoloških promena cementnog tkiva. Obrada kanalnog sistema zuba je opravdana i moguća samo u uslovima stalnog hlađenja vodom, u protivnom nastaju ireverzibilna termička oštećenja intrakanalnog dentina i cementa na apeksu korena zuba

SEM analiza kvaliteta ivičnog pripoja kompozitnih ispuna za gleđ posle primene totalno nagrizajućeg i samonagrizajućeg adhezivnog sistema

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 analyze 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°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 lt 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.Uvod Kvalitet i trajnost veze gleđi i kompozitnih materijala zavisi, između ostalog, i od korišćenog adhezivnog restaurativnog sistema. Cilj rada Cilj istraživanja je bio da se analizom pomoću skening elektronske mikroskopije (SEM) proceni kvalitet ivičnog pripoja kompozitnih adhezivnih sistema i gleđi, odnosno prouče morfološke osobine gleđne površine duž ivica kompozitnih restauracija nakon delovanja kariogenog rastvora. Metode rada Kao materijal u istraživanju korišćeno je 56 ekstrahovanih humanih trećih molara. Na svim zubima su preparirani kaviteti pete klase s ivicama u gleđi. Kaviteti su restaurirani kompozitnim adhezivnim sistemima: Single Bond/Z250 i Single Bond/Filtek Flow, korišćenjem tehnike totalnog nagrizanja, i Prompt-L-Pop/Z250 i Prompt- L-Pop/Filtek Flow, primenom tehnike sa samonagrizajućim adhezivnim sistemima. Posle postupka restauracije zubi su izlagani demineralizaciji tokom sedam i 28 dana potapanjem u kariogeni rastvor (mlečna kiselina pH 4,5; 0,1 M) na 37°C ili držani u dejonizovanoj vodi (kontrolna grupa). Ivice restauracija i perimarginalna gleđ ispitivane su pomoću SEM. Ivična pukotina oko restauracija merena je u predelu vrata zuba, okluzivno i na aproksimalnim stranama. Rezultati Primena tehnike totalnog nagrizanja je pokazala značajno manju širinu ivične pukotine oko kompozitnih restauracija u odnosu na samonagrizajući sistem (p lt 0,01). SEM ispitivanja su takođe otkrila izrazitu demineralizaciju i eroziju ivične zone gleđi (oštećenja prizmi, poroziteti) nakon delovanja kariogenog rastvora kod oba adhezivna sistema. Na gleđnim površinama van perimarginalne zone uočena su neznatna oštećenja. Zaključak Tretman kaviteta sa 35-procentnom fosfornom kiselinom kod totalno nagrizajućeg postupka značajno poboljšava vezu kompozitnih smola za gleđ. Rastvaranje ivične gleđi u kariogenom rastvoru uočeno je oko svih restauracija i kod oba adhezivna sistema

The resistence of conditioned enamel to the effect of cariogenic solution

INTRODUCTION Enamel surface around restoration is very sensitive to the effect of cariogenic solution. It is the consequence of the manner the cavity is prepared before restoration, the existence of marginal cracks around restoration, that is, irregular polishing of filling. OBJECTIVE The aim of this study is to analyze the morphology of the marginal enamel surface around composite fifth class restoration after the application of cariogenic solution. METHOD In this study 28 extracted molars were used. After the V class preparation of the buccal crown surface, teeth samples were divided into two groups. The first group was restored with the composite system Single Bond +Z250, applying the total etching technique. The second group was restorated with Prompt L-pop +Z250 and by applying self-etching primers. After the cavity restoration, teeth samples were kept in demineralising solution (lactic acid, pH 4.5, 0.1 M) at the temperature of 37°C during 7 and 28 days. Control group samples were kept in distilled water during the experiment. The marginal enamel surface analysis was done by a scanning electron microscope. RESULTS The achieved results showed that there was a denivelation and severe demineralization of the perimarginal enamel zone after 7 and 28 days, while on the remaining enamel there were some minor changes. Along the marginal composite/ enamel joint there was the central type of demineralization of enamel prisms and preserved inter prismatic enamel. The existence of pores of different sizes and scattered enamel fractures was established. The marginal joint was mostly without any gaps in the first group samples, while in the second group samples there were narrow or wider edge gaps. CONCLUSION After the application of cariogenic solution, perimarrginal enamel showed conspicuous morphological damage in comparison to the remaining enamel surface