149 research outputs found
Characterisation and microleakage of a new hydrophilic fissure sealant â UltraSeal XTÂź hydroâą
Objectives: The new hydrophilic fissure sealant, UltraSeal XTÂź hydroâą (Ultradent Products, USA), was characterised and its in vitro resistance to microleakage after placement on conventionally acid etched and sequentially lased and acid etched molars was investigated.
Materials and Methods: The sealant was characterised by Fourier transform infra-red spectroscopy, (FTIR), scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX) and Vickers indentation test. Occlusal surfaces of extracted human molars were either conventionally acid etched (n = 10), or sequentially acid etched and laser irradiated (n = 10). UltraSeal XTŸ hydro⹠was applied to both groups of teeth which were then subjected to 2500 thermocycles between 5 and 55 °C prior to microleakage assessment by fuchsin dye penetration.
Results: UltraSeal XTÂź hydroâą is an acrylate-based sealant which achieved a degree of conversion of 50.6 ± 2.2% and a Vickers microhardness of 24.2 ± 1.5 under standard light curing (1000 mWcm-2 for 20 s). Fluoride ion release was negligible within a 14-day period. SEM and EDX analyses indicated that the sealant comprises irregular sub-micron and nano-sized silicon-, barium- and aluminium-bearing filler phases embedded within a ductile matrix. Laser preconditioning was found to significantly reduce microleakage (Mann-Whitney U test, p < 0.001). The lased teeth presented enhanced surface roughness on a 50 to 100 ÎŒm scale which caused the segregation and concentration of the filler particles at the enamel-sealant interface.
Conclusion: Laser preconditioning significantly decreased microleakage and increased enamel surface roughness which caused zoning of the filler particles at the enamel-sealant interface
Effect of Er:YAG laser enamel conditioning and moisture on the microleakage of a hydrophilic sealant
For a given sealant, successful pit and fissure sealing is principally governed by the enamel conditioning technique and the presence of moisture contamination. A new generation of hydrophilic resin sealants is reported to tolerate moisture. This study investigates the impact of Er:YAG laser pre-conditioning and moisture contamination on the microleakage of a recent hydrophilic sealant. Occlusal surfaces of extracted human molars were either acid etched (n = 30), or successively lased and acid etched (n = 30). Ten teeth from each group were either air-dried, water-contaminated, or saliva-contaminated prior to sealing with UltraSeal XTÂź hydroâą. Samples were inspected for penetration of fuchsin dye following 3000 thermocycles between 5 and 50 °C, and the enamelâsealant interfaces were observed by scanning electron microscopy (SEM). Significant differences in microleakage were evaluated using the MannâWhitney U test with Bonferroni adjustment (p = 0.05). Laser pre-conditioning significantly reduced dye penetration irrespective of whether the enamel surface was moist or dry. Microleakageof water-contaminated acid etched teeth was significantly greater than that of their air-dried or saliva-contaminated counterparts. SEM analysis demonstrated good adaptation in all groups with the exception of water-contaminated acid etched teeth which exhibited relatively wide gaps. In conclusion, this hydrophilic sealant tolerates the presence of saliva, although water was found to impair its sealing ability. Laser pre-conditioning significantly decreases microleakage in all cases
The impact of Er:YAG laser enamel conditioning on the microleakage of a new hydrophilic sealant â UltraSeal XTÂź hydroâą
UltraSeal XTÂź hydroâą is a new hydrophilic, light-cured, methacrylate-based pit and fissure sealant which has been developed by Ultradent Products, USA. The sealant is highly filled with a 53 wt.% mixture of inorganic particles which confer both thixotropy and radiopacity. The principal purpose of this study was to investigate the microleakage of UltraSeal XTÂź hydroâą as a function of different enamel etching techniques. The occlusal surfaces of sound, extracted human molars were either acid etched, Er:YAG laser irradiated or successively laser irradiated and acid etched. UltraSeal XTÂź hydroâą was applied to each group of teeth (n=10) which were subjected to a thermocycling process consisting of 2500 cycles between 5 and 50°C with a dwell time of 30s. Microleakage assessments were then carried out using 0.5 % fuchsin dye and optical microscopy. The microleakage score data were analysed using the Kruskal-Wallis, MannâWhitney U test with Bonferroni adjustment. No significant differences in microleakage were noted between the individually acid etched and laser-irradiated groups (p>0.05); however, teeth treated with a combination of laser irradiation and acid etching demonstrated significantly lower microleakage scores (p<0.001). Electron microscopy with energy-dispersive X-ray analysis revealed that the mineral filler component of UltraSeal XTÂź hydroâą essentially comprises micrometre-sized particles of inorganic silicon-, aluminium- and barium-bearing phases. Laser etching increases the roughness of the enamel surface which causes a concentrated zoning of the filler particles at the enamel-sealant interface
InfluĂȘncia de diferentes agentes auxiliares do preparo biomecĂąnico na obturação de canais laterais artificiais
The purpose of the present study was to evaluate the influence of some auxiliary agents of biomechanical preparation of the root canal on the filling of artificial lateral canals in extracted human teeth. A total of eighty single-rooted teeth were employed, which were submitted to preparation of three artificial lateral canals in one of the proximal aspects at the cervical, middle and apical thirds, besides one in the buccal aspect. The main canals were prepared by Profile 0.4 rotary instruments through the crown-down technique and irrigated with the irrigants investigated, as follows: Group A - 1% sodium hypochlorite and final irrigation with trisodium EDTA for 5 minutes; Group B - Endogel (2% chlorhexidine gel); Group C - Endo PTC and Dakin's solution and final irrigation with Tergentol- Furacin; and Group D - File Eze. The root canals were obturated by the Tagger's hybrid technique and then radiographed for assessment of the penetration rate of the filling materials in the lateral canals. Analysis of the results demonstrated no statistically significant difference (pObjetivou-se avaliar a influĂȘncia de alguns agentes auxiliares do preparo biomecĂąnico do canal radicular, na obturação de canais laterais artificiais em dentes humanos extraĂdos. Foram utilizados oitenta dentes unirradiculados nos quais, previamente, foram confeccionados trĂȘs canais laterais artificiais em uma das paredes proximais, nos terços cervical, mĂ©dio e apical e um canal na parede vestibular. Os canais principais foram preparados com instrumentação rotatĂłria, instrumentos Profile 0.4, pela tĂ©cnica rotatĂłria coroa- ĂĄpice e irrigados com a substĂąncia irrigadora estudada, sendo no grupo A - hipoclorito de sĂłdio a 1% e irrigação final com EDTA trissĂłdico por 5 minutos; grupo B - Endogel (gel de clorexidina a 2%); grupo C - Endo PTC e solução de Dakin e irrigação final com tergentol-furacin segundo a tĂ©cnica de Paiva e Antoniazzi e no grupo D - File Eze. Os canais foram obturados pela tĂ©cnica hĂbrida de Tagger e, entĂŁo, radiografados para a anĂĄlise das extensĂ”es de penetração dos materiais obturadores nos canais laterais. ApĂłs a anĂĄlise dos resultados, conclui-se que nĂŁo houve diferença estatĂstica significante (
Testing an expanded set of sustainable forest management indicators in Mediterranean coppice area
Although coppice forests represent a significant part of the European forest area, especially across southern Countries, they received little attention within the Sustainable Forest Management (SFM) processes and scenarios, whose guidelines have been mainly designed to high forests and national scale. In order to obtain âtailoredâ information on the degree of sustainability of coppices on the scale of the stand, we evaluated (i) whether the main coppice management options result in different responses of the SFM indicators, and (ii) the degree to which the considered SFM indicators were appropriate in their application at stand level. The study considered three different management options (Traditional Coppice TC, coppice under Natural Evolution NE, and coppice under Conversion to high forest by means of periodical thinning CO). In each of the 43 plots considered in the study, which covered three different European Forest Types, we applied a set of eighteen âconsolidatedâ SFM indicators, covering all the six SFM Criteria (FOREST EUROPE, 2020) and, additionally, tested other sixteen novel indicators shaped for agamic forests and/or applicable at stand level. Results confirmed that several consolidated indicators related to resources status (Growing stock and Carbon stock), health (Defoliation and Forest damage), and socio-economic functions (Net revenue, Energy and Accessibility) were highly appropriate for evaluating the sustainability of coppice at stand level. In addition, some novel indicators related to resources status (Total above ground tree biomass), health (Stand growth) and protective functions (Overstorey cover and Understorey cover) proved to be highly appropriate and able to support the information obtained by the consolidated ones. As a consequence, a subset of consolidated SFM indicators, complemented with the most appropriate novel ones, may represent a valid option to support the evaluation of coppice sustainability at stand level. An integrated analysis of the SFM indicators showed that NE and CO display significant higher environmental performances as compared with TC. In addition, CO has positive effects also on socio-economic issues, while TC -which is an important cultural heritage and a silvicultural option that may help to keep local communities engaged in forestry â combines high wood harvesting rates with dense understory cover. Overall, each of the three management options showed specific sustainability values; as a consequence, their coexistence at a local scale and in accordance with the specific environmental conditions and the social-economic context, is greatly recommended since it may fulfill a wider array of sustainability issue
Testing an expanded set of sustainable forest management indicators in Mediterranean coppice area
Although coppice forests represent a significant part of the European forest area, especially across southern Countries, they received little attention within the Sustainable Forest Management (SFM) processes and scenarios, whose guidelines have been mainly designed to high forests and national scale. In order to obtain âtailoredâ information on the degree of sustainability of coppices on the scale of the stand, we evaluated (i) whether the main coppice management options result in different responses of the SFM indicators, and (ii) the degree to which the considered SFM indicators were appropriate in their application at stand level. The study considered three different management options (Traditional Coppice TC, coppice under Natural Evolution NE, and coppice under Conversion to high forest by means of periodical thinning CO). In each of the 43 plots considered in the study, which covered three different European Forest Types, we applied a set of eighteen âconsolidatedâ SFM indicators, covering all the six SFM Criteria (FOREST EUROPE, 2020) and, additionally, tested other sixteen novel indicators shaped for agamic forests and/or applicable at stand level. Results confirmed that several consolidated indicators related to resources status (Growing stock and Carbon stock), health (Defoliation and Forest damage), and socio-economic functions (Net revenue, Energy and Accessibility) were highly appropriate for evaluating the sustainability of coppice at stand level. In addition, some novel indicators related to resources status (Total above ground tree biomass), health (Stand growth) and protective functions (Overstorey cover and Understorey cover) proved to be highly appropriate and able to support the information obtained by the consolidated ones. As a consequence, a subset of consolidated SFM indicators, complemented with the most appropriate novel ones, may represent a valid option to support the evaluation of coppice sustainability at stand level. An integrated analysis of the SFM indicators showed that NE and CO display significant higher environmental performances as compared with TC. In addition, CO has positive effects also on socio-economic issues, while TC -which is an important cultural heritage and a silvicultural option that may help to keep local communities engaged in forestry â combines high wood harvesting rates with dense understory cover. Overall, each of the three management options showed specific sustainability values; as a consequence, their coexistence at a local scale and in accordance with the specific environmental conditions and the social-economic context, is greatly recommended since it may fulfill a wider array of sustainability issues
In vitro dentin permeability after application of GlumaÂź desensitizer as aqueous solution or aqueous fumed silica dispersion
Effect of commercially available and experimental potassium oxalate-based dentin desensitizing agents in dentin permeability: influence of time and filtration system
Sealing and dentin bond strength of adhesive systems in selected areas of perfused teeth
Radiographic evaluation of root canal cleaning, main and laterals, using different methods of final irrigation
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