Effect of variations in clinical application of adhesives and composites on the quality of polymerization and bonding to tooth tissues

Uvod: Veliki izbor komercijalnih materijala u restaurativnoj stomatologiji sa različitim preporukama za njihovo korišćenje, objektivne kliničke okolnosti, podaci iz literature i društvene mreže utiču na sve veće varijacije u kliničkoj primeni materijala. Osnovni cilj ove doktorske disertacije je bio ispitivanje uticaja različitih kliničkih tehnika na fizička svojstva adheziva i kompozita i kvalitet veze sa dentinom. Materijal i metode: U ovoj doktorskoj disertaciji su korišćeni: Single Bond Universal (3M), konvencionalni mikrohibridni kompoziti: Herculite XRV (Kerr), Filtek Z250 (3M), tečni kompozit Filtek Ultimate Flowable Restorative (3M), bulk-fill kompoziti: Filtek Bulk Fill Posterior Restorative (3M) i Filtek One Bulk Fill Restorative (3M), politalasna lampa Bluephase G2 (Ivoclar Vivadent) i monotalasna lampa Elipar DeepCure-L (3M). U prvom delu istraživanja ispitivan je, primenom mikro-ramanske spektroskopije, stepen konverzije univerzalnog adheziva u zavisnosti od položaja svetlosnog izvora i jačina veze univerzalnog adheziva sa dentinom mikroistezanjem, nakon 24 h i 6 meseci, u zavisnosti od protokola aplikacije adheziva (protokol totalnog nagrizanja-TE ili samonagrizanja-SE) i položaja svetlosnog izvora. U drugom delu istraživanja termoparovima je merena promena temperature u funkciji vremena zagrejanog ili nezagrejanog bulk-fill kompozita, koji je aplikovan u kavitet II klase na humanom molaru i adaptiran zagrejanim ili nezagrejanim instrumentom. U trećem delu istraživanja analiziran je stepen konverzije tečnog kompozita polimerizovanog kroz pastozne kompozite različite vrste i temperature. U četvrtom delu istraživanja ispitivani su jačina veze i tipovi fraktura univerzalnog adheziva sa dentinom mikroistezanjem nakon aplikacije tečnog i zagrejanog ili nezagrejanog bulk-kompozita, pri čemu je svetlosna polimerizacija tečnog i bulk- fill kompozita vršena odvojeno ili zajedno. Rezultati su analizirani parametarskim testovima sa nivoom značajnosti od =0,05. Rezultati: Pri promeni ugla svetlosnog izvora u odnosu na dentinsku površinu od 90 na 60, uočena je statistički manja vrednost stepena konverzije univerzalnog adheziva (p<0,05). Kada je adheziv aplikovan TE protokolom, inicijalna jačina veze, bez obzira na položaj svetlosnog izvora je bila viša u odnosu na grupe sa SE protokolom, ipak samonagrizanje je rezultovalo stabilnijom vezom nakon starenja (p>0,05). Razlika u temperaturi zagrejanog i nezagrejanog kompozita u kavitetu bila je manja od 4C već 30 sekundi nakon aplikacije. Duža ekspozicija od 20 s, politalasnom lampom nije dovela do značajno viših vrednosti stepena konverzije (p>0,05) tečnog materijala, polimerizovanog kroz bulk-kompozit. Nije uočena značajna razlika (p>0,05) prilikom prosvetljavanja tečnog kompozita kroz sloj bulk-fill materijala bez obzira na vrstu LED lampe. Nijansa pastoznog mikrohibridnog kompozita nije značajno uticala (p>0,05) na stepen konverzije tečnog kompozita dok je zagrejani kompozit pokazao značajno više vrednosti stepena konverzije (p<0,05) u odnosu na većinu grupa. Zasebna polimerizacija slojeva dovodi do značajno viših vrednosti stepena konverzije tečnog kompozita u odnosu na "snow-plow" tehniku. Starenje, temperatura bulk-fill materijala kao i način aplikacije kompozita nisu uticale na jačinu veze mikroistezanjem univerzalnog adheziva i dentina (p>0,05). Zaključak: Tokom svetlosne polimerizacije univerzalnih adheziva svetlosnim izvorima visokog intenziteta upravni ugao vrha vodiča svetla imao je veći uticaj na kvalitet polimerizacije u odnosu na manja odstupanja distance. Na dentinu, protokol samonagrizanja rezultovao je dugoročno stabilnijom adhezivnom vezom nego protokol totalnog nagrizanja...Introduction: A growing range of commercially avaliable materials in restorative dentistry with diiferent recommendations for use, objective clinical circumstances, literature data and social networks lead to variations in materials’ clinical use. The aim of this disertation was to evaluate effects of different clinical techniques on physical properties of adhesive and composite and bond strength to dentine. Material and Methods: The folowing materials were used: Single Bond Universal (3M) (SBU), coventional microhybrid composites: Herculite XRV (Kerr), Filtek Z250 (3M), flowable composite Filtek Ultimate Flowable Restorative (3M) (FC), bulk-fill composites: Bulk Fill Posterior Restorative (3M) and Filtek One Bulk Fill Restorative (3M), polywave light curing unit Bluephase G2 (Ivoclar Vivadent) (LCU_G2) and monowave LCU Elipar DeepCure-L (3M) (LCU_ELI). In the first part, the degree of conversion (DC) of SBU was determined using microRaman spectroscopy in relation to different positions of the LCU_G2. Depending on the etching protocol "total-etch" (TE) or "self-etch" (SE) and LCU_G2 position, shear bond strength of SBU to dentine was evaluated after 24h and 6 months. In the second part, preheated (PH) or ambient temperature (AT) bulk-fill composite was placed and condensed using PH or AT instrument in a II class cavity on a human third molar. Temperature change was monitored over time using thermocouples. In the third part, the DC of a flowable composite was evaluated after polymerization through different types and temperatures of high viscosity composites. In the fourth part, micro-tensile bond strength (μTBS) and failure types of SBU to dentine were evaluated in relation to different temperature and application of a flowable and bulk-fill composite, polymerized separately or simultaneously. Data were analyzed using parametric tests at a level of significance =0.05. Results: Statistically lower DC of SBU adhesive was detected as LCU_G2 tip angulation changed from 90° to 60° (p<0.05). Initial bond strength of SBU_TE was higher than SE groups, regardless of the LCU_G2 position, although SE groups showed more stable bond strengths in the long term (p>0.05). Temperature difference between PH and AT composite was less than 4 C, 30 s after their application into the cavity. There was no statistically significant difference in DC (p>0.05) when the FC was cured through bulk-fill, using LCU_G2 longer than 20 s. FC cured through bulk-fill showed comparable DC values (p>0.05), regardless of the LCU type. The shade of the conventional composite did not significantly affect the DC of FC (p>0.05), while PH composite resulted in higher DC than most of the groups (p<0.05). When layers were polymerized separately, the DC of FC was significantly higher compared to the "snow-plow" technique. Artificial ageing, temperature of the bulk-fill material and composite application technique did not affect μTBS of SBU to dentine (p>0.05). Conclusion: During light curing of SBU with a high-intesity LCU, 90° angle of the light tip had a greater effect on the quality of polymerization than minor distance departures. SE protocol on dentine resulted in more stable long-term bond strength than TE. Separate polymerization of both layers (flowable and bulk-fill composite) produced higher DC, although with no impact on bond strength, in comparison to simultaneous polymerization of layers. Preheated composite was prone to rapid cooling during the first minute of use. Preheating of dental composites resulted in higher DC, however without notable differences in bond strength..

Temperature changes in the pulp chamber induced by polymerization of resin-based dental restoratives following simulated direct pulp capping

The objective of this study was to measure temperature changes in the pulp chamber induced by polymerization of resin-based dental restoratives following a simulated procedure of direct pulp capping. Class I cavities with a microperforation at the pulp horn were prepared in extracted human molar teeth. The complete procedure of direct pulp capping and cavity restoration was performed with the root part of extracted teeth fixed in a water bath at 37 degrees C. Mineral trioxide aggregate, bioactive dentin substitute or calcium-hydroxide paste were used as pulp capping materials. Cavities were restored with a light-cured or chemically-cured resin-modified glass ionomer, universal adhesive and a bulk-fill composite, cured with a high-intensity LED unit. Pulp capping materials caused a slight temperature decrease. Lower temperature increase was recorded during light-curing of the glass ionomer liner after direct capping with mineral trioxide aggregate and calcium-hydroxide than that recorded for the bioactive dentin substitute. Adhesive light-curing increased temperature in all groups with higher mean temperatures in groups with chemically-cured as compared to those for the light-cured glass ionomer liner. Direct pulp capping with mineral trioxide aggregate or calcium-hydroxide followed by the light-cured resin-modified glass ionomer liner and a bonded bulk-fill composite restoration induced temperature changes below the potentially adverse threshold of 42.5 degrees C

Effect of variations in clinical application of adhesives and composites on the quality of polymerization and bonding to tooth tissues

Uvod: Veliki izbor komercijalnih materijala u restaurativnoj stomatologiji sa različitim preporukama za njihovo korišćenje, objektivne kliničke okolnosti, podaci iz literature i društvene mreže utiču na sve veće varijacije u kliničkoj primeni materijala. Osnovni cilj ove doktorske disertacije je bio ispitivanje uticaja različitih kliničkih tehnika na fizička svojstva adheziva i kompozita i kvalitet veze sa dentinom. Materijal i metode: U ovoj doktorskoj disertaciji su korišćeni: Single Bond Universal (3M), konvencionalni mikrohibridni kompoziti: Herculite XRV (Kerr), Filtek Z250 (3M), tečni kompozit Filtek Ultimate Flowable Restorative (3M), bulk-fill kompoziti: Filtek Bulk Fill Posterior Restorative (3M) i Filtek One Bulk Fill Restorative (3M), politalasna lampa Bluephase G2 (Ivoclar Vivadent) i monotalasna lampa Elipar DeepCure-L (3M). U prvom delu istraživanja ispitivan je, primenom mikro-ramanske spektroskopije, stepen konverzije univerzalnog adheziva u zavisnosti od položaja svetlosnog izvora i jačina veze univerzalnog adheziva sa dentinom mikroistezanjem, nakon 24 h i 6 meseci, u zavisnosti od protokola aplikacije adheziva (protokol totalnog nagrizanja-TE ili samonagrizanja-SE) i položaja svetlosnog izvora. U drugom delu istraživanja termoparovima je merena promena temperature u funkciji vremena zagrejanog ili nezagrejanog bulk-fill kompozita, koji je aplikovan u kavitet II klase na humanom molaru i adaptiran zagrejanim ili nezagrejanim instrumentom. U trećem delu istraživanja analiziran je stepen konverzije tečnog kompozita polimerizovanog kroz pastozne kompozite različite vrste i temperature. U četvrtom delu istraživanja ispitivani su jačina veze i tipovi fraktura univerzalnog adheziva sa dentinom mikroistezanjem nakon aplikacije tečnog i zagrejanog ili nezagrejanog bulk-kompozita, pri čemu je svetlosna polimerizacija tečnog i bulk- fill kompozita vršena odvojeno ili zajedno. Rezultati su analizirani parametarskim testovima sa nivoom značajnosti od =0,05. Rezultati: Pri promeni ugla svetlosnog izvora u odnosu na dentinsku površinu od 90 na 60, uočena je statistički manja vrednost stepena konverzije univerzalnog adheziva (p<0,05). Kada je adheziv aplikovan TE protokolom, inicijalna jačina veze, bez obzira na položaj svetlosnog izvora je bila viša u odnosu na grupe sa SE protokolom, ipak samonagrizanje je rezultovalo stabilnijom vezom nakon starenja (p>0,05). Razlika u temperaturi zagrejanog i nezagrejanog kompozita u kavitetu bila je manja od 4C već 30 sekundi nakon aplikacije. Duža ekspozicija od 20 s, politalasnom lampom nije dovela do značajno viših vrednosti stepena konverzije (p>0,05) tečnog materijala, polimerizovanog kroz bulk-kompozit. Nije uočena značajna razlika (p>0,05) prilikom prosvetljavanja tečnog kompozita kroz sloj bulk-fill materijala bez obzira na vrstu LED lampe. Nijansa pastoznog mikrohibridnog kompozita nije značajno uticala (p>0,05) na stepen konverzije tečnog kompozita dok je zagrejani kompozit pokazao značajno više vrednosti stepena konverzije (p<0,05) u odnosu na većinu grupa. Zasebna polimerizacija slojeva dovodi do značajno viših vrednosti stepena konverzije tečnog kompozita u odnosu na "snow-plow" tehniku. Starenje, temperatura bulk-fill materijala kao i način aplikacije kompozita nisu uticale na jačinu veze mikroistezanjem univerzalnog adheziva i dentina (p>0,05). Zaključak: Tokom svetlosne polimerizacije univerzalnih adheziva svetlosnim izvorima visokog intenziteta upravni ugao vrha vodiča svetla imao je veći uticaj na kvalitet polimerizacije u odnosu na manja odstupanja distance. Na dentinu, protokol samonagrizanja rezultovao je dugoročno stabilnijom adhezivnom vezom nego protokol totalnog nagrizanja...Introduction: A growing range of commercially avaliable materials in restorative dentistry with diiferent recommendations for use, objective clinical circumstances, literature data and social networks lead to variations in materials’ clinical use. The aim of this disertation was to evaluate effects of different clinical techniques on physical properties of adhesive and composite and bond strength to dentine. Material and Methods: The folowing materials were used: Single Bond Universal (3M) (SBU), coventional microhybrid composites: Herculite XRV (Kerr), Filtek Z250 (3M), flowable composite Filtek Ultimate Flowable Restorative (3M) (FC), bulk-fill composites: Bulk Fill Posterior Restorative (3M) and Filtek One Bulk Fill Restorative (3M), polywave light curing unit Bluephase G2 (Ivoclar Vivadent) (LCU_G2) and monowave LCU Elipar DeepCure-L (3M) (LCU_ELI). In the first part, the degree of conversion (DC) of SBU was determined using microRaman spectroscopy in relation to different positions of the LCU_G2. Depending on the etching protocol "total-etch" (TE) or "self-etch" (SE) and LCU_G2 position, shear bond strength of SBU to dentine was evaluated after 24h and 6 months. In the second part, preheated (PH) or ambient temperature (AT) bulk-fill composite was placed and condensed using PH or AT instrument in a II class cavity on a human third molar. Temperature change was monitored over time using thermocouples. In the third part, the DC of a flowable composite was evaluated after polymerization through different types and temperatures of high viscosity composites. In the fourth part, micro-tensile bond strength (μTBS) and failure types of SBU to dentine were evaluated in relation to different temperature and application of a flowable and bulk-fill composite, polymerized separately or simultaneously. Data were analyzed using parametric tests at a level of significance =0.05. Results: Statistically lower DC of SBU adhesive was detected as LCU_G2 tip angulation changed from 90° to 60° (p<0.05). Initial bond strength of SBU_TE was higher than SE groups, regardless of the LCU_G2 position, although SE groups showed more stable bond strengths in the long term (p>0.05). Temperature difference between PH and AT composite was less than 4 C, 30 s after their application into the cavity. There was no statistically significant difference in DC (p>0.05) when the FC was cured through bulk-fill, using LCU_G2 longer than 20 s. FC cured through bulk-fill showed comparable DC values (p>0.05), regardless of the LCU type. The shade of the conventional composite did not significantly affect the DC of FC (p>0.05), while PH composite resulted in higher DC than most of the groups (p<0.05). When layers were polymerized separately, the DC of FC was significantly higher compared to the "snow-plow" technique. Artificial ageing, temperature of the bulk-fill material and composite application technique did not affect μTBS of SBU to dentine (p>0.05). Conclusion: During light curing of SBU with a high-intesity LCU, 90° angle of the light tip had a greater effect on the quality of polymerization than minor distance departures. SE protocol on dentine resulted in more stable long-term bond strength than TE. Separate polymerization of both layers (flowable and bulk-fill composite) produced higher DC, although with no impact on bond strength, in comparison to simultaneous polymerization of layers. Preheated composite was prone to rapid cooling during the first minute of use. Preheating of dental composites resulted in higher DC, however without notable differences in bond strength..

Brašno - Kruh '13

The "Flour-Bread '13“ Congress topics were the following: breeding and quality of cereal grains, grain storage and milling technology, analytical and rheological methods, baking technology, improvers and additives, starch and modified starch, extrusion and pasta production, biscuit and pastry products, nutritional quality of cereals, cereal food safety and cereal based functional foods