Immersion Regime Research Articles

Erosive Effect of Canned Juices and Soft Drinks on Surface Roughness of Restorative Materials Used in Pediatric Dentistry: An Ex Vivo Study.

To evaluate and compare the effect of fruit juice (orange) and cola drink (noncarbonated) on the surface texture of composite (3M ESPE Filtek Bulk Fill) and glass ionomer cement (GIC) (ChemFil Superior). A total of eighty pellets each were prepared with composite (3M ESPE Filtek Bulk Fill) and GIC (ChemFil Superior) material using a brass mold with an inner diameter of 3 mm and a thickness of 3 mm according to the manufacturer's instructions. Around 10 pellets of each material were placed in airtight plastic containers. The baseline surface texture value was obtained by profilometer. An 8-day immersion regime was carried out according to Maupome et al. After the 8-day test period, pellets were reevaluated for surface texture final value. The values were statistically analyzed. A statistically significant lower surface roughness of composite restorative material was observed when treated with high-concentration orange juice and medium-concentration. Conversely, a statistically significant lower surface roughness of GIC restorative material was observed when it was treated with the low-concentration group, high-concentration orange juice, and medium-concentration orange juice. The surface roughness patterns of restorative materials increased as the number of immersion regimes increased. Vishwanathaiah S, Maganur PC, Khabrany HM, et al. Erosive Effect of Canned Juices and Soft Drinks on Surface Roughness of Restorative Materials Used in Pediatric Dentistry: An Ex Vivo Study. Int J Clin Pediatr Dent 2024;17(7):807-811.

Comparative Evaluation of Microleakage of Fiber-reinforced Glass Ionomer Cement and Conventional Glass Ionomer Cement Restorations Immersed in Three Different Beverages: In Vitro Study.

The aim of the study was to compare and evaluate the microleakage of fiber-reinforced glass ionomer cement (GIC) and conventional glass ionomer cement restorations immersed in three different beverages. A total of 96 human exfoliating deciduous molars were selected which were cleaned and disinfected. Standardized Class V cavity preparations were done and buccal surface were restored with experimental fiber-reinforced glass ionomer cement (Exp-FRGIC), lingual surface were restored with Type II conventional GIC. They were divided into four groups according to the test beverage. The samples were subjected to various immersion regimes and evaluated for microleakage under stereomicroscope. Intragroup comparison for (Exp-FRGIC) showed significant microleakage when immersed in fresh fruit juice at high immersion whereas intragroup comparison in conventional GIC, showed highest microleakage with soft drink. Intergroup comparison of (Exp-FRGIC) in high immersion regime, showed more microleakage with specimen immersed in soft drink followed by fresh fruit juice. It can thus be concluded that the three beverages used in the study affected the microleakage of both restorative materials significantly. Increasing usage of fruit juices in the pediatric diet has a definite impact on the progression of caries and it directly or indirectly affects the quality of restorations placed in the oral cavity. How to cite this article: George MA, Chandak SA, Khekade SH, et al. Comparative Evaluation of Microleakage of Fiber-reinforced Glass Ionomer Cement and Conventional Glass Ionomer Cement Restorations Immersed in Three Different Beverages: In Vitro Study. J Contemp Dent Pract 2024;25(4):346-353.

Leaching and cytotoxicity of bismuth oxide in ProRoot MTA - A laboratory investigation.

The present study examined the leaching and cytotoxicity of bismuth from ProRoot MTA and aimed to identify whether bismuth leaching was affected by the cement base and the immersion regime used. The leaching profile of bismuth was examined from ProRoot MTA and compared with hydroxyapatite containing 20% bismuth oxide as well as hydroxyapatite and tricalcium silicate to investigate whether bismuth release changed depending on the cement base. Bismuth leaching was determined after 30 and 180 days of ageing immersed in Dulbecco's modified Eagle's medium (DMEM) using mass spectroscopy (ICP-MS). The media were either unchanged or regularly replenished. The pH, surface microstructure and phase changes of aged materials were assessed. Wistar rat femoral bone marrow stromal cells (BMSCs) and cutaneous fibroblasts were isolated, cultured and seeded for cell counting (trypan blue live/dead) after exposure to non-aged, 30- and 180-days-aged samples in regularly replenished DMEM. Aged DMEM in contact with materials was also used to culture BMSCs to investigate the effect of material leachates on the cells. Gene expression analysis was also carried out after direct exposure of cells to non-aged materials. Differences between groups were statistically tested at a significance level of 5%. All materials exhibited alterations after immersion in DMEM and this increased with longer exposure times. The bismuth leached from ProRoot MTA as detected by ICP-MS. Aged ProRoot MTA samples exhibited a black discolouration and surface calcium carbonate deposition. ProRoot MTA influenced cell counts after direct exposure and its 180-days leachates reduced BMSC viability. After direct BMSC contact with non-aged ProRoot MTA an upregulation of metallothionein (MT1 and MT2A) expression and down-regulation of collagen-1a (Col-1a) and bone sialoprotein (BSP) expression was identified. Bismuth leaching was observed throughout 180-days observation period from all materials containing bismuth oxide. This negatively influenced cell viability and gene expression associated with bismuth exposure. This is the first study to report that metallothionein gene expression was influenced by exposure to ProRoot MTA.

Feature and mechanism analysis of dispersive soil disintegration impacted by soil water content, density, and salinity

AbstractDispersive soil has caused innumerable water‐induced erosion failures of earthen structures in arid regions up to now, among which disintegration, as the first response process, is commonly deemed as the primary inducement but with inadequate understanding. In this study, the disintegration characteristics of a compacted dispersive lean clay with sand were investigated by carrying out laboratory disintegration tests under a water immersion regime. Soil mass water content (ω), dry density (ρd) and total soluble salt content (η) were considered. Results suggest that for dispersive soil, (1) the disintegration process exhibited two distinct modes, which was divided by the ω near the optimum water content; (2) higher ρd delayed disintegration monotonously; (3) increasing η first weakened and then enhanced the disintegration, in which pattern the η at the inflection point increased with increasing ρd, showing a density dependence. Evolutions of representative soil morphology were illustrated. More importantly, the underlying influential mechanism of ω and η to disintegration were elaborated emphatically: (1) the initial clay dispersion level, soil consistency change, and conceptual “constraint force” exerted by soil matric suction jointly determine the disintegration modes; (2) increasing η makes the soil pore solution concentration higher and microstructure simpler, competition between the two leads to nonmonotonic change patterns of disintegration completion time (Td) and defined velocity (Vd); the interactive effect of ρd and η manifests that η produces an additional influence on the base of microstructure created by ρd. Finally, the grey relation entropy analysis was introduced to evaluate the contributions of the three test variables to Td and Vd. The obtained results and proposed perspectives are expected to be conducive to a deeper comprehension of the same or relevant behaviours of dispersive soils in the presence of water, so as to provide new insights for the targeted prevention and control of dispersive soil catastrophes.Highlights Disintegration of dispersive soil shows two distinct water content‐dependent modes. Soil salinity has a two phase impact on disintegration of dispersive soil. Dry density and soil salinity interact affecting disintegration. Relationship between soil dispersion and disintegration is elaborated.

Penetration of Solid Bodies into Concrete

The results of an experimental study of quasistatic and dynamic penetration of solids into sand concrete are presented.Cylindrical bodies with conical tips and a ball were used. The resistance forces are compared for the taper angles of 180◦, 90◦, 60◦, 30◦, 9.5◦ and a ball. The flow character in the quasistatic immersion regime and in dynamic immersion due to inertia is determined.

Comparative evaluation of micro-leakage of two newer glass ionomer cements in primary molars immersed in three beverages: in vitro study

The dietary habits of children expose the oral cavity to challenging environments. A durable interface between the restorative material and tooth surface is essential to ensure marginal integrity thereby contributing to the longevity of restoration. The objective of this study was to compare the micro-leakage of two newer glass ionomer cements (SDI Riva Self Cure GIC and GC Fuji IX GP EXTRA) in primary molars immersed in sugarcane juice, chocolate milk and mango drink. The study included 60 extracted non carious upper and lower primary molars. The buccal and lingual surfaces were restored with SDI Riva Self Cure GIC and GC Fuji IX GP EXTRA respectively. The sample was divided into three groups (chocolate milk, mango drink, sugarcane juice). Each group (n=18) was further subdivided into three subgroups based on the immersion regime. Six teeth were kept as control. The teeth were immersed in Rhodamine B dye. Following this, micro-leakage was determined under 40 x stereomicroscope. Both the materials showed micro leakage when immersed in the three beverages. When specimen under each group were compared, the microleakage score increased with an increase in immersion frequency. This was not statistically significant. The microleakage values for both the materials immersed in the three beverages were not significant. Both the materials used in this study can be conveniently used in restoration of primary molars.

Effect of Soft Drinks and Fresh Fruit Juice on Surface Roughness of Commonly used Restorative Materials.

ABSTRACTIn this in vitro study, the effects of a Cola drink, and fresh fruit juice (citrus) on the surface roughness on flowable composite and resin-modified glass ionomer cement (RMGIC) each was evaluated and compared. Using a brass mold 70 pellets each of flowable composite (Filtek™ Flow) and RMGIC tricure restorative material were prepared according to the manufacturer’s instructions. Two groups (groups I and II) were formed containing 30 pellets of each material. Remaining 10 pellets of each restorative material did form the control group [water (group III)]. Experimental group pellets were again divided into three subgroups (mild, moderate and severe) containing 10 pellets each and were kept in plastic containers with 30 ml Cola drink (group I) and fresh fruit juice (group II) respectively. Immersion regime was followed according to M aupome G et al. Baseline and final surface roughness (Ra) value for each pellet was evaluated using a profilometer. Statistical analysis was done with Wilcoxon’s signed rank test and analysis of variance (ANOVA) followed by Mann-Whitney test. Results showed that the erosive effect of both Cola drink and fresh fruit juice caused significant surface roughness on both flowable composite and RMGIC restorative materials in the mild, moderate and severe immersion regimes.How to cite this article: Maganur P, Satish V, Prabhakar AR, Namineni S. Effect of Soft Drinks and Fresh Fruit Juice on Surface Roughness of Commonly used Restorative Materials. Int J Clin Pediatr Dent 2015;8(1):1-5.

Erosive potential of cola and orange fruit juice on tooth colored restorative materials.

Background:Erosion is a common condition which manifests due to consumption of high caloric and low pH acidic food stuffs such as carbonated drinks and fruit juices which cause irreversible damage to dental hard tissues and early deterioration of the dental restorations.Aim:The main aim of this study is to evaluate and to compare the erosive potential of carbonated drink (cola) and fruit juice (orange fruit juice) by measuring the surface roughness (Ra) values on two commonly used dental restorative materials.Materials and Methods:A total of 36 specimens each were prepared using both testing materials, compomer (Group I) and giomer (Group II). Six specimens in each group were discarded due to wide variation in pre exposed Ra values and the remaining 30 specimens in each group were further sub divided into 10 samples each according to the testing media used. Immersion regime was followed according to Von Fraunhofer and Rogers. The pre and post immersion surface roughness values were recorded using a profilometer.Results:Both tested materials showed statistically-significant surface erosion (P < 0.01) when exposed to cola and orange fruit juice than the control group (water).Discussion:Compomer showed more surface roughness when compared to giomer when exposed to the three tested media which can be attributed to the variation in filler content, decomposition of resin matrix and fallout of the fillers in composites when exposed to acidic drinks. Other factors responsible for this significant erosion were also discussed.Conclusions:Significant surface changes of the dental restorative materials can take place when exposed to low pH drinks for a prolonged period.

Damage of Cement Paste in Sulfate Environment with Different Temperature and Drying-Immersion Cycles

Damage of cement paste under attack of sodium sulfate solution with different temperature and regime were carried out in this paper. Experimental study was executed on cement paste admixed by fly ash and GGBS. Sulfate concentration is 33.8g/l SO42- solution (5% by mass of Na2SO4). Two exposure regimes are employed in this study including immersion and drying-immersion cycles. In immersion regime, the temperature of sulfate solution is room temperature, 50°C and 80°C. Physical properties and sulfate ion distribution of paste were systematically tested during 150 days of sulfate exposure. And effects of raised temperature and drying-immersion cycles on deterioration of paste were also determined. The experimental results show that the strength, mass and expansion rate of paste improves initially and then progressively degrade until failure in sulfate environment. Beside chemical attack, which is major damage factor to paste in immersion regime, crystallized thenardite results in surface scaling of paste in drying-immersion cycles. Raised temperature and drying-immersion cycles accelerate the physical properties evolution process and increase the effective sulfate diffusion coefficient.

Erosive Effect of Soft Drink and Fresh Fruit Juice on Restorative Materials

ABSTRACT Aims To evaluate and compare the effect of a soft drink and a fresh fruit juice on microleakage as well as surface texture of flowable composite (Filtek” Flow 3M Dental products) and resin-modified glass ionomer cement (GIC) (Vitremer” 3M Dental products). Materials and methods Seventy noncarious human premolars extracted for orthodontic treatment purpose were collected and stored in saline for microleakage study. The experimental groups comprised of 60 teeth, while the remaining 10 formed the control group. Class V cavities were prepared and restored with RMGIC on the buccal surface and Filtek Flow on the lingual surface for evaluating microleakage. The experimental samples were then divided into two groups (group I: Cola drink and group II: Fresh orange fruit juice) of 30 teeth. Each of this group was further divided into three subgroups (low, medium and high immersion) containing 10 teeth. The control group (group III: Water) contained 10 teeth. Using a brass mold, 56 pellets were prepared with Filtek” Flow and Vitremer” tri-cure restorative material each for studying surface texture. Again these were divided into experimental group of 48 pellets each and control group of eight pellets each. The experimental samples were then divided into two groups (group I: Cola drink and group II: Fresh orange fruit juice) of 24 pellets of each. Each of this group was further divided into three subgroups (low, medium and high immersion) containing eight pellets each. The control group (group III: Water) contained 16 pellet (eight pellets of each material). Both the teeth and pellets were subjected to a common immersion regime according to Maupome et al. Microleakage was evaluated by using Rhodamine B dye and surface texture was evaluated prior to immersion and final surface roughness (Ra) after subjecting the pellets to immersion regime. Statistical analyses used were Chi-square test/Fisher exact test, Wilcoxon's signed rank test and Mann-Whitney test and ANOVA test. Results and conclusion The teeth and the pellets showed statistically significant microleakage and surface roughness respectively as the immersion regime increased. Thus, the study conclusively proves that the 'sipping habit’ associated with commonly available low pH beverages, are detrimental to the longevity of restorations. How to cite this article Maganur PC, Prabhakar AR, Satish V, Namineni S, Kurthukoti A. Erosive Effect of Soft Drink and Fresh Fruit Juice on Restorative Materials. World J Dent 2013;4(1): 32-40.

Alleviation of hyperhydricity of sugarcane plantlets produced in RITA® vessels and genotypic and phenotypic characterization of acclimated plants

The effect of employing a RITA® system in one or both of somatic embryo induction and germination stages was investigated, and it was deemed far superior to a semi-solid (agar) substrate in terms of in vitro plant yields for sugarcane genotype N41. Approximately 18,000 plants/leaf roll were obtained in vitro in 12 weeks, when both culture stages were undertaken using temporary immersion, compared with approximately 2000 plants/leaf roll produced on semi-solid medium. However, due to hyperhydricity, only ~ 34% of the plants produced in RITA® survived acclimatization. To overcome this, and realize the potential yields of the RITA® system, various culture conditions were investigated, viz. nutrient and sucrose supplies, a rockwool substrate and the immersion regime. Of these, increasing the resting time between immersions from 1 min/12 h to 1 min/72 h, and lowering MS nutrient to 1/2 strength, proved the most beneficial, resulting in 60% acclimation success. Genetic fidelity of these plants was investigated by AFLP analyses where only 0–0.9%, of polymorphic bands were scored compared with the conventionally- propagated N41 control. Phenotypic characterization of plants grown in the field for 6 months showed that, although all in vitro derived plants had a reduced stalk diameter relative to the control, there were no significant differences regarding stalk mass, height and population.

Nanopatterning in Langmuir-Blodgett Monolayers of a Thermoresponsive Double Hydrophilic Block Copolymer Studied by Atomic Force Microscopy

The microphase-separation of Langmuir-Blodgett (LB) monolayers of a rhodamine B (RhB) end-labeled double hydrophilic block copolymer (DHBC), RhB-Poly(N,N-dimethylacrylamide)-b-poly(N,N-diethylacryl-amide) (RhB-PDMA(207)b-PDEA177) and the 1:1 segmental mixture of PDEA and RhB-PDMA homopolymers was followed by AFM. The DHBC LB films revealed a loose distribution of nano-aggregates with variable geometries below the lower critical solution temperature (LCST) of PDEA (32 degrees C) and low surface pressure (3 mN m(-1)). By increasing either the temperature above the LCST of PDEA or the surface pressure beyond the immersion regime of PDMA in the subphase (7 mN m(-1)) a dense nanopatterning was obtained. The absence of a corresponding regular nanopatterning in LB films of mixed homopolymers with the same composition highlights the role of the covalent bonding between PDEA and PDMA on the self-segregation of the two blocks at the air-water interface.

Evaluation of Microleakage of RMGIC and Flowable Composite Immersed in Soft Drink and Fresh Fruit Juice: An in vitro Study.

ABSTRACTAim : The objective of the study was to evaluate and compare the effect of a soft drink and a fresh fruit juice on the microleakage of flowable composite and resin modified glass lonomer cement (RMGIC).Methods and materials : 70 non-carious human premolars were collected and stored in saline until further use. Class-V cavities were prepared and restored with RMGIC on the buccal surface and flowable composite on the lingual surface for evaluating microleakage. The experimental groups (Group I and II ) comprised of 60 teeth, while the remaining 10 formed the control group (Group III―Water). The experimental groups were further divided into 2 groups (Group I―Cola drink and Group II―Fresh orange fruit juice) of 30 teeth each. Each group was then further divided into 3 subgroups (Short, Medium and Long-immersion) containing 10 teeth as shown in flow chart.Immersion regime was followed according to Maupome G et al and microleakage was evaluated by using Rhodamine B dye and examined under stereomicroscope.Results : Microleakage data obtained was statistically analyzed by Chi-square test. The teeth showed statistically significant microleakage as the immersion regime increased.Interpretation and Conclusion : Low pH soft drink caused highly significant microleakage at the tooth and restorative material interface in medium and high immersion regimes signifying that the leakage pattern was directly proportional to the number of immersions. Thus, the study conclusively proves that the ‘sipping habit’ associated with commonly available low pH beverages is detrimental to the longevity of restorations.

Assessment of Fracture Properties of Emulsified Asphalt Mixtures

ABSTRACT This paper presents an investigation into factors affecting the fracture properties of a cold-laid material used as base or binder course on medium to lightly trafficked roads. The Semi-Circular Bending beam test has been used to study the effect of temperature and rate of loading on the fracture properties, expressed as fracture toughness and fracture energy, of the cold-laid material in mode I. A Hot Mix Equivalent mixture was used in the study comprising the same aggregates and base binder. An immersion regime adopting vacuum moisture saturation was undertaken to assess the effect of ingested moisture on the measured fracture properties. At −10 and −20°C, the fracture toughness of the cold material was almost independent of temperature. At—20°C, the fracture energy of the cold and hot materials were almost equal irrespective of loading rate. The cold mixture attained reasonably high retained fracture toughness upon vacuum moisture saturation.

Assessment of Fracture Properties of Emulsified Asphalt Mixtures

ABSTRACT This paper presents an investigation into factors affecting the fracture properties of a cold-laid material used as base or binder course on medium to lightly trafficked roads. The Semi-Circular Bending beam test has been used to study the effect of temperature and rate of loading on the fracture properties, expressed as fracture toughness and fracture energy, of the cold-laid material in mode I. A Hot Mix Equivalent mixture was used in the study comprising the same aggregates and base binder. An immersion regime adopting vacuum moisture saturation was undertaken to assess the effect of ingested moisture on the measured fracture properties. At −10 and −20°C, the fracture toughness of the cold material was almost independent of temperature. At—20°C, the fracture energy of the cold and hot materials were almost equal irrespective of loading rate. The cold mixture attained reasonably high retained fracture toughness upon vacuum moisture saturation.

Effect of postharvest heat treatments on fruit quality, surface structure, and fungal disease in Valencia oranges

The effect of prestorage heat treatments on the quality of Valencia oranges and on postharvest disease was investigated during a 6-week storage trial. Fruit receiving a hot water immersion regime (45�C core temperature for 42 min) designed to disinfest against Queensland fruit fly lost significantly less moisture and remained firmer during storage than unheated control fruit. Disinfestation treatment also significantly reduced fruit acidity and number of viable spores of Colletotrichum gloeosporioides, Penicillium digitatum, and P. italicum. The gradual heating process involved with disinfestation was more successful in maintaining fruit quality than surface sterilisation by hot water immersion (12 min at 53�C), or conditioning in air (24 h at 30�C and 90% relative humidity). Heat-treated fruit showed enhanced colour development. Light and electron microscopy studies showed that heating had little effect on the structure of surface waxes; however, collapsed oil glands were observed after cool storage. Prestorage heat treatments could be a favourable alternative to chemicals for control of pests.