Number of the Dentinal Tubules as a Function of Cavity Dept

Svrha ovog istraživanja je utvrditi postoji li razlika između broja i promjera otvora eksponiranih dentinskih tubula te udjela površine otvora eksponiranih dentinskih tubula od ukupne površine poprečnog presjeka humanoga koronarnog dentina s obzirom na udaljenost prema caklinsko-dentinskom spojištu i pulpi. Scanning elektronsko-mikroskopska usporedbena raščlamba provedena je na 60 uzoraka humanoga koronarnog dentina razdijeljenih u tri skupine prema udaljenosti između pulpe i caklinsko-dentinskog spojišta. promatran je dentin na tri razine u području središnje fisure: 1. poprečni rez koronarnoga dentina, 1 mm ispod caklinsko-dentinskoga spojišta 2. poprečni rez koronarnoga dentina na polovini razmaka između caklinsko-dentinskoga spojišta i pulpne komore 3. poprečni rez koronarnoga dentina 1 mm iznad krova pulpne komore Izbrojeni su vidljivi dentinski tubulusi unutar kvadrata površine 50 µm x 50 µm. Dobiveni broj podijeljen je s 2500 da bi se dobio N/µm2 i pomnožen s 1.000.000 da bi se dobio N/mm2). Prosječan broj otvora eksponiranih dentinskih tubula na prvoj razini je 96000/mm2, na drugoj razini 27100/mm2, te na trećoj 58.300/mm2. Jednosmjernom raščlambom varijance dobiven je omjer MStretman/MS pogrješka 305,22, koji je veći od F 0,99 (2,57) 4,98. Rezultati upućuju da postoji statistički znatna razlika broja i promjera otvora eksponiranih dentinskih tubula i veličine površine koju zauzimaju sve tri promatrane skupine uzoraka.The aim of this study was to determine if there is any defference between the number of exposed dentinal tubules on the cross section of the coronal dentine. By scanning electron microscopy comparative observation was carried out on 60 specimens of human coronal dentine, divided into 3 groups, in relation to the distance from the enamel-dentine junction and the pulp. Coronal dentine in the region of the central fissure was observed on three levels: 1. Cross section of the coronal dentine, 1 mm from the enamel-dentine junction. 2. Cross section of the coronal dentine, half-distance between the enamel-dentine junction and the pulp. 3. Cross section of the coronal dentine, 1 mm from the roof of the pulp chamber. Openings of the exposed dentinal tubules were counted in a square size 50 x 50 µm of the dentinal surface. The number was divided by 2500 to obtain the number of the openings of the dentinal tubules in the square micrometer (N/µm2). This number was multiplied by 106 to obtain the number of the openings of the dentinal tubules in the square millimeter (N/mm2). The mean number of the openings of the dentinal tubules on the first level was 9600/mm2, on the second level 27100/mm2 and on the third level 58300/mm2. Using the one-way analysis of variance was found ratio MStreatment/MSerror 305.22, that was greater than F 0.99 (2.57) 4.98. The results showed that there is significant statistical difference in the number of exposed dentinal tubules between all three groups of specimens

S.E.M. Analysis of the Interaction Between Green Or and the Dentine

Svrha ovoga rada bila je ispitati međuodnos desenzibilizatora dentina Green Ora i restorativnih materijala uporabljenih kod adhezijskih preparacija te možebitni učinak na sposobnost adhezije tih materijala na caklinu i dentin. Green Or se rabi za smanjenje bolne preosjetljivosti zuba, tako da uzrokuje mehaničko zatvaranje dentinskih tubulusa ili inhibira repolarizaciju neurona. Mehaničko zatvaranje dentinskih tubulusa postiže se stvaranjem kompaktnoga kristaličnog precipitata, koji pokriva površinu izloženoga dentina, a depolarizacija neurona postiže se otpuštanjem kalijeva iona. Ispitivanje je provedeno na 6 humanih trećih molara izvađenih zbog ortodontskih ili parodontoloških indikacija. Zubi su podijeljeni na tri skupine od dva zuba s obzirom na materijal uporabljen za ispun: tekući i mikro-hibridni kompozit ili srebrni amalgam. U svakoj smo skupini na zidove dentinskoga kaviteta aplicirali desenzibilizator Green Or te S.E.M. raščlambom, pri velikom stupnju povećanja, promatrali kakav je njegov utjecaj na spoj između dentina i restorativnoga materijala. Svi su se uzorci proučavali na Skening Elektronskom Mikroskopu (S.E.M.) Zavoda za kontrolu kvalitete Pliva u Zagrebu. Rezultati S.E.M. raščlambe pri velikom stupnju povećanja, u sve tri proučavane skupine zuba, pokazuju usku povezanost primijenjenih materijala s caklinom i dentinom. Mikroskopiranje spojišta dentina i materijala korištenih za ispun u Grupi A i B pokazalo je da upotreba green ora ne ometa adhezijsku sposobnost adhezivno-kompozitnih materijala za dentinsku plohu niti utječe na brtvljenje cakline i dentina. Sloj desenzibilizatora nerazlučivo je povezan sa slojem adheziva i kompozita što omogućuje čvrsto prianjanje na dentinske zidove kaviteta. Rezultati dobiveni u skupini C, u kojoj je upotrijebljen srebrni amalgam kao materijal za punjenje, pokazuju da Green Or također nije utjecao na adheziju slitine za stjenke cakline i dentina. Prema mnogim autorima upotreba Green Ora kao podloge kod kompozitnih ili amalgamskih ispuna nije smanjivala adhezijsku sposobnost spomenutih restorativnih materijala. Rezultati dobiveni u istraživanju pokazuju da Green Or stvara sloj koji jednolično prekriva i zatvara dentinske tubuluse i omogućuje dobru izolaciju dubokih dijelova dentina od restorativnih materijala. Time se postiže zadovoljavajuće brtvljenje dentinskih tubulusa i smanjuje dentinska preosjetljivost na intraoralne nociceptivne stimulanse, gotovo u njezinoj akutnoj fazi. Promatranje različitih dijelova dentina na skening elektronskom mikroskopu (S.E.M.) pokazuje da desenzibilizator dentina uspostavlja zadovoljavajuću i snažnu povezanost s različitim adhezivnim materijalima ili sa srebrnim amalgamom uporabljenima u istraživanju.The aim of this study was to evaluate the interaction between Green Or, a dentinal desensitizer, and restorative materials used in adhesive preparation, and its possible influence on the adhesiveness of those materials to the enamel and dentine. Green Or is used to reduce pain sensation in hypersensitive teeth by mehanical occlusion of the dentine tubules or the inhibition of neuronal repolarization. Mehanical occlusion is made by blocking the dentine tubules with a compact crystaline precipitate that covers the exposed dentine surface, while the neural depolarization is produce by released potassium ions. The investigation included 6 human third molars extracted for orthodontic or periodontal reasons. The teeth were divided into three groups of 2 teeth each according to the type of material used for filling: fluid and mycrohybrid composites, and silver amalgam. In every group we applied the desensitizer green or onto the walls of the dental cavities and with S.E.M. observation at high degree of magnification investigated how it affevts the conjunction of dentine and restorative materials. All speciments were observed with the Scansion Electron Microscope (S.E.M.) at the “Department of Quality Control” pliva in Zagreb. The results of S.E.M. observation at very high magnification in all three investigated groups show the close connection of the applied materials to the enamel an dentine. Microscoping the conjunction beetween the dentine and materials we used for filling in Groups A and B, showed that the use of Green Or does not alter the adhesiveness of the restorative adhesive-composite materials to the dental wall, nor does it modifies their sealing action on enamel and dentine. The desensitizer layer is indistinguishable with the adhesive-composite layers which enables strong adherence to the dentinal walls of cavities. The results obtained in group C specimens, in which silver amalgam was used as a filling material, show that Green Or did not interfere with the adhesion process of the alloy and the enamel and dentine. As found by many authors, the desensitizer Green Or, when used as a liner in the tooth filled with resins or alloys, did not decrease the adhesion of the restorative materials. The results obtained in the study show that Green Or is able to form a uniform layer that covers and occludes dentine tubules and enables good isolation of deep dentine from the restorative materials. This should constitute an efficacious sealing of dentinal tubules and provoke a decrease in dentinal sensitivity to intraoral nociceptive stimuli, almost in the acute phase. Observation of different dental sections with a Scanning Electron Microscope (S.E.M.) shows that desensitizer established an efficient and powerful interconnection with the different adhesive materials or silver amalgam utilized in the study

Number of the Dentinal Tubules as a Function of Cavity Dept

Svrha ovog istraživanja je utvrditi postoji li razlika između broja i promjera otvora eksponiranih dentinskih tubula te udjela površine otvora eksponiranih dentinskih tubula od ukupne površine poprečnog presjeka humanoga koronarnog dentina s obzirom na udaljenost prema caklinsko-dentinskom spojištu i pulpi. Scanning elektronsko-mikroskopska usporedbena raščlamba provedena je na 60 uzoraka humanoga koronarnog dentina razdijeljenih u tri skupine prema udaljenosti između pulpe i caklinsko-dentinskog spojišta. promatran je dentin na tri razine u području središnje fisure: 1. poprečni rez koronarnoga dentina, 1 mm ispod caklinsko-dentinskoga spojišta 2. poprečni rez koronarnoga dentina na polovini razmaka između caklinsko-dentinskoga spojišta i pulpne komore 3. poprečni rez koronarnoga dentina 1 mm iznad krova pulpne komore Izbrojeni su vidljivi dentinski tubulusi unutar kvadrata površine 50 µm x 50 µm. Dobiveni broj podijeljen je s 2500 da bi se dobio N/µm2 i pomnožen s 1.000.000 da bi se dobio N/mm2). Prosječan broj otvora eksponiranih dentinskih tubula na prvoj razini je 96000/mm2, na drugoj razini 27100/mm2, te na trećoj 58.300/mm2. Jednosmjernom raščlambom varijance dobiven je omjer MStretman/MS pogrješka 305,22, koji je veći od F 0,99 (2,57) 4,98. Rezultati upućuju da postoji statistički znatna razlika broja i promjera otvora eksponiranih dentinskih tubula i veličine površine koju zauzimaju sve tri promatrane skupine uzoraka.The aim of this study was to determine if there is any defference between the number of exposed dentinal tubules on the cross section of the coronal dentine. By scanning electron microscopy comparative observation was carried out on 60 specimens of human coronal dentine, divided into 3 groups, in relation to the distance from the enamel-dentine junction and the pulp. Coronal dentine in the region of the central fissure was observed on three levels: 1. Cross section of the coronal dentine, 1 mm from the enamel-dentine junction. 2. Cross section of the coronal dentine, half-distance between the enamel-dentine junction and the pulp. 3. Cross section of the coronal dentine, 1 mm from the roof of the pulp chamber. Openings of the exposed dentinal tubules were counted in a square size 50 x 50 µm of the dentinal surface. The number was divided by 2500 to obtain the number of the openings of the dentinal tubules in the square micrometer (N/µm2). This number was multiplied by 106 to obtain the number of the openings of the dentinal tubules in the square millimeter (N/mm2). The mean number of the openings of the dentinal tubules on the first level was 9600/mm2, on the second level 27100/mm2 and on the third level 58300/mm2. Using the one-way analysis of variance was found ratio MStreatment/MSerror 305.22, that was greater than F 0.99 (2.57) 4.98. The results showed that there is significant statistical difference in the number of exposed dentinal tubules between all three groups of specimens