In Vitro Progression of Artificial White Spot Lesions Sealed With an Infiltrant Resin

2014 ◽  
Vol 39 (5) ◽  
pp. 481-488 ◽  
Author(s):  
R Gelani ◽  
AF Zandona ◽  
F Lippert ◽  
MM Kamocka ◽  
G Eckert

SUMMARY This study assessed the ability of an infiltrant resin (Icon, DMG Chemisch-Pharmazeutische Fabrik GmbH, Hamburg, Germany) to prevent artificial lesion progression in vitro when used to impregnate white spot lesions and also assessed the effect of saliva contamination on resin infiltration. Enamel specimens (n=252) were prepared and covered with nail varnish, leaving a window of sound enamel. After demineralization (pH 5.0; four weeks), specimens were divided into six groups (n=42 per group): group 1, 2% fluoride gel (positive control); group 2, resin infiltrant; group 3, resin infiltrant + fluoride gel; group 4, no treatment (negative control); group 5, resin infiltrant application after saliva contamination; and group 6, resin infiltrant + fluoride gel after saliva contamination. Specimens from each group were cut perpendicular to the surface, and one-half of each specimen was exposed to a demineralizing solution for another four weeks. The other half was set aside as a record of initial lesion depth and was used later in the determination of lesion progression. Lesion progression and infiltrant penetration were measured using confocal laser scanning microscopy (CLSM) and transverse microradiography (TMR). For lesion depth, based on CLSM, groups 2 and 3 showed the least changes when submitted to demineralization challenge, followed by group 1, then groups 5 and 6, and finally group 4. There were no significant differences between groups 2 and 3 or groups 5 and 6 in their ability to inhibit further lesion progression (p<0.05). Based on TMR, groups 2 and 3 also showed the fewest changes when submitted to demineralization challenge, followed by group 5, then groups 1 and 6, and finally group 4. In terms of mineral loss as measured by TMR, all groups that contained fluoride (groups 1, 3, and 6) show less percentage change in mineral loss than the groups that did not contain fluoride (groups 2, 4, and 5). It can be concluded that infiltrant penetration into early enamel lesions inhibited further demineralization in vitro, especially in the presence of fluoride. Saliva contamination decreased the ability of the infiltrant to prevent further demineralization, but the presence of fluoride seemed to counteract this effect.

2003 ◽  
Vol 17 (4) ◽  
pp. 337-341 ◽  
Author(s):  
Flávia Bittencourt Pazinatto ◽  
Bruno Barbosa Campos ◽  
Leonardo César Costa ◽  
Maria Teresa Atta

Thermocycling simulates, in vitro, thermal changes that occur in the oral cavity. The aim of this study was to evaluate the influence of the number of cycles on microleakage. Class V cavities (1.5 mm deep, 3 mm in height and 3 mm in width) were prepared in bovine teeth, restored with a Single Bond/Z250 restorative system (3M/ESPE) and then divided into five groups of ten teeth each: group 1 was not thermocycled (control group), and groups 2, 3, 4 and 5 were thermocycled 500, 1,000, 2,500 and 5,000 times, respectively (5º-55º ± 2ºC, 15 s dwell time). The teeth were immersed in 0.5% basic fuchsin aqueous solution for 24 h, sectioned and the sections with the highest degree of microleakage were selected, scanned and the extent of dye penetration was measured by the ImageTool program. The results submitted to one-way ANOVA showed no significant differences between the groups (p > 0.05). The averages of microleakage values in millimeters were: group 1 (3.92); group 2 (3.13); group 3 (4.48); group 4 (4.33) and group 5 (3.42). Thus, it was concluded that there is no relation between the increase of the number of cycles and the increase in microleakage.


2020 ◽  
Vol 11 (1) ◽  
pp. 280-284 ◽  
Author(s):  
Julietpoornamathy J ◽  
Parameswari C.S.

In medical sciences, toxicity is an area wherein extensive studies have been carried to improve the diseases as well as to prevent. So, there is a high requirement for novel and improved alternative therapeutic strategies to manage diseases. The liver is the largest gland in the body, which executes several important mechanisms; it stores minerals and vitamins and releases them in periods of need. The main aim of this study was to give a closer insight into potent non- toxic compounds that is capable of modifying the responses. Animals were divided into five equal groups viz control (Group 1), administered with food and water ad libitum, (Group 2) administered with olive oil, (Group 3) administered with zingerone, (Group 4) administered with concanavalin A, (Group 5) administered with cyclosporine A followed by zingerone. Our results revealed significant changes in liver marker enzymes and liver histology of zingerone treated rats when compared to control rats.  A corollary, zingerone has no toxic effect on hepatocytes and was found to be safe at a dose of 10mg/kg b wt and also ameliorates hepatotoxicity.


2021 ◽  
Vol 11 (5) ◽  
pp. 970-975
Author(s):  
Khold Al Ahdal ◽  
Laila Al Deeb ◽  
Mohammed S. Bin-Shuwaish ◽  
Rana S. Al-Hamdan ◽  
Modhi Al Deeb ◽  
...  

The aim of the present study was to evaluate the efficacy of interfacial bonding between resin cement and titanium alloy conditioned with different Photobiomodulataion Therapy (PBT) in comparison with conventional regimes. Seventy-five samples of titanium bar were segmented polished; and based on conditioning regime divided into five groups (15 each specimens). Group 1: No treatment (control), Group 2: Sand blasting with 120 µm Al2O3, Group 3: Er,Cr:YSGG (ECL), Group 4: Er:YAG laser (EYL), Group 5: Nd:YAG laser (NYL). After different conditioning regimes, resin cement was mixed and applied. All specimens were thermocycled for 500 cycles and positioned on universal testing machine for shear bond strength testing. Modes of failure was assessed by a single examiner using stereomicroscope at 40× magnification. Three pairs of specimens in each group were sputter coated and scanning electron microscope (SEM) images were taken at 1000× magnification using 20 Kv. The highest SBS values were observed in group 2 (14.25±2.29 MPa) and the lowest bond values were displayed in group 1 (6.98 ±0.59 MPa). Titanium alloy abutments conditioned with different laser prototypes ECL (11.22±1.40 MPa), EYL (9.29±1.22 MPa) and NYL (9.12 ±1.84 MPa) exhibited comparable SBS (p > 0.05). Adhesive failures were primarily dominant among all experimental groups. Photo-biomodulation in the form of ECL lasers has the potential to be used as a supplement to sandblasting procedure in conditioning of cement retained titanium alloy implant abutments.


2012 ◽  
Vol 2012 ◽  
pp. 1-5
Author(s):  
Vitor Cesar Nakamura ◽  
Simony Hidee Hamoy Kataoka ◽  
Giulio Gavini ◽  
Patrícia Helena Ferrari ◽  
Silvana Cai

Objective. To evaluate through FE-SEM the cleanliness and dentinal alterations promoted by different methods of dental sample preparation.Methods. Twenty-five human single-rooted teeth were used. The teeth were cleaned and autoclaved in wet medium and randomly divided into 5 groups (), according to the preparation methods employed—control group: no solutions applied; group 1: cement removal and irrigation with 5.25% % EDTA for 4 minutes each; group 2: 17%  % NaOCl (4 minutes ultrasonic bath); group 3: cement removal and 17%     buffer solution + distilled water (10 minutes ultrasonic); group 4: 17%   NaOCl (3 minutes ultrasonic bath). Specimens were analyzed by field emission scanning electron microscope (FE-SEM), at 1500x magnification. Data were submitted to qualitative analysis according to a scoring system and submitted to Kruskal-Wallis test.Results. In ascending order, as to bind parameters, (i) cleanliness: control, group 2, group 3, group 5, and group 4, (ii) dentinal alterations: group 1, group 5, group 2, group 3, and group 4.Conclusion. The proposed protocol was suitable for subsequent microbiological contamination, because it showed less dentinal morphological alterations with increased removal of organic waste.


2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
D. Dionysopoulos ◽  
C. Papadopoulos ◽  
E. Koliniotou-Koumpia

Aim.The aim of this study was to evaluate the effect of different restoration techniques on the formation of internal microgaps between materials and dentin in class V restorations.Materials and Methods.Twenty-five extracted human premolars were prepared with standardized class V cavity outlines (3 mm × 2 mm × 2 mm). The cavities were randomly divided into 5 groups of 10 cavities each and restored according to manufacturer’s instructions: Group 1: preheating (55°C) conventional composite (Filtek Z250), Group 2: flowable composite (Filtek Flow), Group 3: Filtek Flow + Filtek Z250 light-cured separately, Group 4: Filtek Flow + Filtek Z250 light-cured simultaneously, and Group 5 (control): Filtek Z250 at room temperature (23°C). The specimens were then thermocycled and cross-sectioned through the center of the restoration. Subsequently, impressions were taken, and epoxy resin replicas were made. The internal adaptation of the materials to the axial wall was analyzed under SEM.Results.The preheated Filtek Z250 (Group 1) showed better internal adaptation than the room temperature groups(P<0.05). The combination of Filtek Flow with Filtek Z250 which was light-cured separately (Group 3) exhibited better internal adaptation than control group(P<0.05).Conclusion.Different restoration techniques exhibit different behavior regarding internal adaptation to dentin after photopolymerization.


2021 ◽  
Vol 14 (4) ◽  
pp. 1508-1513
Author(s):  
Ibraheem F Alshiddi

In order to assess the influence of finishing and polishing on the surface brightness and color stability of the ceramic veneer, fifty specimens were fabricated with 10 mm diameter and 2 mm thickness using IPS E-Max Ceramic. After glazing, 10 specimens were untouched as control group, and the other 40 specimens were abraded using 125µm diamond bur to create surface roughness. Forty specimens were divided into four groups (n=10), in group 1: specimens were finished using diamond point, in group 2 specimens’ surface was polished with a polishing kit, Group 3: Each specimen surface was polished with the polishing kit as in protocol 2 and was polished a polishing past and group 4 Each specimen was glazed by heating at 621℃ for 3 minutes followed by a temperature increase of 83℃/min up to 918℃ for 30 seconds. Color measurement was performed using spectrophotometer. Color stability data were analyzed using two-way ANOVA and Tukey’s HSD test (α=0.05). For Ra values, paired-samples t-tests were used to analyze the data and compare groups. The change in L and E showed a significant difference among the study groups; (group 1, group 2, group 3 and group 4) with respect to three variables L, a and b. A significant difference was noted when compared each group with the control; however, only group 2 showed a significant difference from group 4; the remaining groups demonstrated similar findings for all three variables. The study displayed a significant impact of the finishing and polishing technique on the surface brightness and color stability of ceramic restoration. However, it was evident that combination of two or three polishing techniques which includes polish kit and glaze enhances the surface finish and adds color stability by alternating the yellow – blue axis (increase in b) and red- green axis (decrease in a).


2020 ◽  
Vol 8 (D) ◽  
pp. 53-57
Author(s):  
Shashidhar Chandrashekhar ◽  
Dinesh Rao ◽  
Jyothi Shashidhar ◽  
Smitha Naik

AIM: The aim of the present study was to evaluate the effect of various intermediate irrigating solutions in the removal of orange-brown precipitate formed due to alternative use of sodium hypochlorite (NaOCl) and chlorhexidine (CHX) root canal irrigants. METHODS: The root canals of 50 mandibular premolars were prepared using ProTaper Universal Rotary instruments (Dentsply Maillefer, Ballaigues, Switzerland) up to size F3. The roots were randomly divided into five experimental groups specified by the intermediate irrigant used; Group 1: No intermediate irrigant used (control), Group 2: Saline, Group 3: 7% maleic acid (MA), Group 4: 4% sodium thiosulfate, and Group 5: 70% isopropyl alcohol (n = 10). After final irrigation with CHX, the specimens were evaluated for the presence/absence of orange-brown precipitate under stereomicroscope. RESULTS: Mean precipitate for all experimental groups was calculated using ANOVA F test which showed orange-brown precipitate (parachloroanaline) in all groups except Group 4 and Group 5 which were highly significant (p < 0.001) at all the levels of root canal. Intergroup pairwise comparison was done using Tukey’s post hoc test. CONCLUSION: About 7% MA is effective in minimizing the formation of orange-brown precipitate when used as intermediate irrigant between NaOCl and CHX. However, the precipitate was not observed with 4% sodium thiosulfate and 70% isopropyl alcohol.


2018 ◽  
Vol 2 ◽  
pp. 39
Author(s):  
Shahinur Nahar Moury ◽  
Md. Touhiduzzaman Sarker ◽  
Adhita Sri Prabakusuma ◽  
Md. Imrul Hasan Russel ◽  
Md. Shahidul Islam

The main purpose of this study was to explore the effects of Spirulina (Spirulina platensis) as a feed supplement by replacing Vitamin-Mineral Premix on the performance of broiler. The study explored that final body weight was 1039, 1070, 1044, 1065, 1117 and 893 g/bird in group 1, 2, 3, 4, 5 and 6 where significantly (p<0.5) higher weight observed in Spirulina group (5) but lower in negative control group (6). Feed intake observed more or less similar in all groups (1483±24g; p>0.5). Feed conversion ratio (kg FI/kg LWG) observed significantly different like 1.72, 1.65, 1.69, 1.62, 1.61 and 1.99 in group 1, 2, 3, 4, 5 and 6 respectively (p<0.5) where higher in negative group (6) and control group (1), but is lowest and similar in 75% Spirulina group (4) and highest (100%) Spirulina group (5). %Ash of different dietary groups were 46.35, 46.54, 48.93, 49.93, 55.07 and 46.92 of group 1, 2, 3, 4, 5 and 6 respectively. The %ash of bone was gradually increased among dietary groups and the best result was obtained in 100% Spirulina group 5 (55.07). It also revealed that diets containing no vitamin-mineral premix with 100% Spirulina improve the performance of broiler. The findings suggest that poultry farmer can use spirulina as a feed item for broiler for more yield.


2008 ◽  
Vol 52 (No. 9) ◽  
pp. 413-418 ◽  
Author(s):  
S. Cech ◽  
R. Dolezel

Different procedures of treatment of large follicular ovarian cysts in 177 sows using GnRH, hCG and PGF2α are evaluated in this study. Ovarian cysts were diagnosed by transcutaneous ultrasonography, which was a part of routine pregnancy diagnosis. No treatment was performed in the control group (Group 1, <i>n</i> = 29); the method of treatment used in the other groups immediately after the diagnosis was intramuscular administration of lecirelin in doses 50 µg (Group 2, <i>n</i> = 28), 100 µg (Group 3, <i>n</i> = 27) and 200 µg divided into 2 equal doses administered at a 12-hour interval (Group 4, <i>n<i> = 25) and of hCG in doses 1 500 IU (Group 5, <i>n</i> = 23), 3 000 IU (Group 6, <i>n</i> = 21), and 250 µg of cloprostenol (Group 7, <i>n</i> = 24). Insemination rate (IR), conception rate (CR) in inseminated sows, pregnancy rate (PR = recovery rate), treatment-insemination interval (TII) and treatment-pregnancy interval (TPI) within 42 days after the initial examination were evaluated. In addition PR in groups of sows divided according to parity (1–3, 4–6 and ≥ 7) were also evaluated. IR and PR were higher in Group 4 (84.0% and 44.0%) and lower in Group 1 (17.2% and 6.9%) in comparison with the other groups (<i>P</i> < 0.001 and <i>P</i> < 0.05). CR, TII and TPI did not differ between the experimental groups. PR were similar in sows with different parity. The study proved a positive response in sows with large follicular ovarian cysts to the treatment consisting of 2 administrations of 100 µg GnRH at a 12-hour interval.


2017 ◽  
Vol 28 (2) ◽  
pp. 206-209 ◽  
Author(s):  
José Eliú Pereira Jurubeba ◽  
Ana Rosa Costa ◽  
Lourenço Correr-Sobrinho ◽  
Carlos Alberto Malanconi Tubel ◽  
Américo Bortolazzo Correr ◽  
...  

Abstract The aim of this study was to evaluate the effect of different number of thermal cycles on the shear bond strength (SBS) of metallic orthodontic brackets bonded to feldspathic ceramic by a composite resin. Twenty-five ceramic cylinders were etched with 10% hydrofluoric acid for 60 s and received two layers of silane. Brackets were bonded to the cylinders using Transbond XT and assigned to 5 groups (n=5): Group 1 - Control group (without thermal cycling); Group 2 - 500 thermal cycles; Group 3 - 5,000 thermal cycles; Group 4 - 7,000 thermal cycles and Group 5 - 10,000 thermal cycles. Light-activation was carried out by Radii Plus LED. SBS testing was carried out after 24 h of storage in deionized water and thermal cycling (5/55 oC and 30 s dwell time). Five brackets were bonded to each cylinder, totalizing 25 brackets for each group. Data were submitted to one-way ANOVA and Tukey’s test (α=0.05). The Adhesive Remnant Index (ARI) was evaluated at 8× magnification. The SBS (MPa) of control group (9.3±0.8), 500 (9.0±0.7) and 5,000 (8.4±0.9) thermal cycles were significantly higher than those after 7,000 (6.8±0.6) and 10,000 (4.9±1.0) thermal cycles (p<0.05). The ARI showed a predominance of Scores 0 (adhesive failure) prevailed in all groups, as shown by the ARI, with increased scores 1 and 2 (mixed failures) for control group and 500 thermal cycles. In conclusion, thermal fatigue may compromise the bonding integration between metallic brackets and ceramic restorations. For in vitro testing, use of at least 7,000 cycles is advised to result in significant fatigue on the bonding interface.


Sign in / Sign up

Export Citation Format

Share Document