Radiotherapy Reduces Microhardness and Mineral and Organic Composition, and Changes the Morphology of Primary Teeth: An in vitro Study

2018 ◽  
Vol 53 (3) ◽  
pp. 296-304 ◽  
Author(s):  
Lenita Marangoni-Lopes ◽  
Gabriela Rovai-Pavan ◽  
Carolina Steiner-Oliveira ◽  
Marinês Nobre-dos-Santos

Objective: We aimed to evaluate whether radiotherapy causes changes in the mineral composition, hardness, and morphology of enamel and dentin of primary teeth. Materials and Methods: Thirty specimens of primary teeth were subjected to radiotherapy. At baseline and after 1,080, 2,160, and 3,060 cGy, the specimens were subjected to microhardness, FT-Raman spectroscopy, and scanning electron microscopy (SEM) analysis. The pH of artificial saliva was determined, as were the calcium and phosphate concentrations. The data were subjected to the Shapiro-Wilk normality test, showed a nonnormal distribution, and were compared by the Kruskal-Wallis test. Results: The results showed that the microhardness of the enamel surface decreased after 2,160 cGy (281.5 ± 58 kgf/mm2) when compared to baseline (323.6 ± 59.5 kgf/mm2) (p = 0.045). For dentin, the surface hardness decreased after 1,080 cGy (34.9 ± 11.4 kgf/mm2) and 2,160 cGy (26 ± 3.5 kgf/mm2) when compared to baseline (56.5 ± 7.7 kgf/mm2) (p < 0.0001). The mineral and organic contents of phosphate (p < 0.0001), carbonate (p < 0.0001), amide (p = 0.0002), and hydrocarbons (p = 0.0031) of enamel decreased after 3,060 cGy (5,178 ± 1,082, 3,868 ± 524, 999 ± 180, and 959 ± 168 kgf/mm2, respectively). For dentin, we noticed a growing increase in phosphate v2, amide, and hydrocarbon content after 1,080 cGy (8,210 ± 2,599, 5,730 ± 1,818, and 6,118 ± 1,807 kgf/mm2, respectively) and 2,160 cGy (1,0071 ± 2,547, 7,746 ± 1,916, and 8,280 ± 2,079 kgf/mm2, respectively) and a reduction after 3,060 cGy (6,782 ± 2,175, 3,558 ± 1,884, and 3,565 ± 1,867 kgf/mm2, respectively) (p < 0.0001). SEM images showed cracks on enamel and degradation of peritubular dentin. Conclusion: We concluded that radiotherapy caused a reduction in surface hardness, changed mineral and organic composition, and promoted morphological changes on the enamel and dentin of primary teeth.

2011 ◽  
Vol 35 (3) ◽  
pp. 277-282 ◽  
Author(s):  
TR Chaitra ◽  
VV Subba Reddy ◽  
GM Devarasa ◽  
TL Ravishankar

Objective: Preventive procedures using pit and fissure sealants are one of the important aspects of pediatric dental practice. The objectives of this in vitro study were to comparatively evaluate microleakage and resin tag penetration of a flowable resin used as a sealant on molars after preparation with Conventional, Enameloplasty and Fissurotomy techniques. Method: A total of 48 teeth were divided into 3 groups (n-16). Group A(CST),Group B (EST),and Group C (FT). Following the fissure preparation sealant was applied as per manufacturer's instructions. 8 samples in each group were used for Microleakage and Resin tag analysis. Microleakage analysis was done under Stereomicroscope after Methylene blue dye immersion by using scoring system. The resin tag analysis was done by measuring the length of resin tags on scanning electron microscope (SEM) images consisting of 10μm scale taken under optical zoom of 2000 X. Results: Significantly lesser microleakage score (P&lt;0.01) and longer resin tag penetration (P&lt;0.001) observed in EST(mean score 0.5±0.53) & (12.19±1.93μm) when compared to CST(mean score 1.75±0.89) & (5.96±1.84μm)and FT (mean score 1.5±0.53) & (6.76±1.82μm) which showed more microleakage and short resin tags. No statistical significance between CST and FT was found. Conclusion: EST has proven to be an excellent method for preparation of pits and fissures when Flowable composite is used as a sealant because of its lesser microleakage and longer resin tag penetration.


2017 ◽  
Vol 68 (1) ◽  
pp. 125-127
Author(s):  
Alexandrina Muntean ◽  
Anca Stefania Mesaros ◽  
Anca Porumb ◽  
Stanca Cuc ◽  
Marioara Moldovan ◽  
...  

The aim of this in vitro study was to assess the enamel surface appearance and Adhesive Remnant Index (ARI) after braces removal. On teeth vestibular surfaces 90 braces were bonded as follows: metallic, ceramics respectively sapphire using as bonding material Opal Seal� (Ultradent, SUA). Teeth were divided in 3 groups (N=30) and stored for 3 months in artificial saliva, tea and Coca-Cola�. For teeth stored in tea and Coca Cola�, ARI express lower values, indicating a risk for enamel injury as fracture occurs at adhesive-enamel interface. From practical point of view, this in vitro study enhance that braces detachment, finishing and polishing are risk manoeuvres for enamel surface. Materials used for collage must present specific properties in order to reduce enamel fracture.


2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Mohideen S. Farook ◽  
Okba Mahmoud ◽  
Maysara Adnan Ibrahim ◽  
Marwah Berkathullah

Objectives. To evaluate the in vitro effectiveness of desensitizing agents in reducing dentine permeability. Methods. The efficacy of desensitizing agents in reducing dentine permeability by occluding dentine tubules was evaluated using a fluid filtration device that conducts at 100 cmH2O (1.4 psi) pressure, and SEM/EDX analyses were evaluated and compared. Forty-two dentine discs ( n = 42 ) of 1 ± 0.2   mm width were obtained from caries-free permanent human molars. Thirty dentine discs ( n = 30 ) were randomly divided into 3 groups ( n = 10 ): Group 1: 2.7% wt. monopotassium-monohydrogen oxalate (Mp-Mh oxalate), Group 2: RMGI XT VAR, and Group 3: LIQ SiO2. Dentine permeability was measured following treatment application after 10 minutes, storage in artificial saliva after 10 minutes and 7 days, and citric acid challenge for 3 minutes. Data were analysed with a repeated measures ANOVA test. Dentine discs ( n = 12 ) were used for SEM/EDX analyses to acquire data on morphological changes on dentine surface and its mineral content after different stages of treatment. Results. Desensitizing agents’ application on the demineralized dentine discs exhibited significant reduction of permeability compared to its maximum acid permeability values. Mp-Mh oxalate showed a significant reduction in dentine permeability ( p < 0.05 ) when compared to RMGI XT VAR and LIQ SiO2. On SEM/EDX analysis, all the agents formed mineral precipitates that occluded the dentine tubules. Conclusions. 2.7% wt. monopotassium-monohydrogen oxalate was significantly effective in reducing dentine permeability compared to RMGI XT VAR and LIQ SiO2.


2021 ◽  
Vol 11 (6) ◽  
pp. 14389-14402

The present in vitro study aims to evaluate pre- and probiotic liquids' effect on surface roughness values of restorative materials after one month of immersion. 360 disc-shaped samples (5mm x 2mm) were prepared from two types of glass-ionomer cements (GIC), a resin-modified GIC, a compomer, three bulk-fill composites, and one microhybrid composite. After the surfaces were polished, samples were divided into three groups (n = 15) and immersed for 10 minutes daily for one month in either a probiotic sachet, kefir (prebiotic), or artificial saliva. After that, the surface roughness values were measured by a profilometer. Scanning electron microscopy (SEM) evaluations of one sample from tested materials were also added. Statistical data were analyzed using one-way ANOVA and Bonferroni–Dunn tests. One of the GIC materials had significantly rougher surfaces in the probiotic sachet, followed by the compomer (p < 0.05). The compomer showed the roughest surfaces after immersion in kefir, followed by the microhybrid composite (Z250). Probiotic sachets formed rougher surfaces than kefir among samples. SEM images revealed the inorganic filler structures and microcracks on the surfaces. A high-viscosity glass-ionomer cement, Equia Fil Forte, and other composite-based materials tested in the present study can be used in pediatric patients who use pre- and probiotic supplements.


2017 ◽  
Vol 11 (1) ◽  
pp. 15-33 ◽  
Author(s):  
Nasibe Aycan Yilmaz ◽  
Ertan Ertas ◽  
Hasan Orucoğlu

Background/Objective: The purpose of this study was to evaluate the efficacy and durability of five different dentin desensitizers (Gluma Desensitizer Powergel, Bifluorid 12, Gluma Self Etch Bond, D/Sense Crystal, Nupro Sensodyne Prophylaxis Paste with Novamin) on tubule occlusion and dentin permeability reduction in vitro. Method: The quantitative changes in permeability of 100 dentin discs were measured after desensitizer treatments and following post-treatments of 6% citric acid challenge for 1 min or immersion in artificial saliva for 24 hours under hydrostatic pressure generated by a computerised fluid filtration meter. Qualitative SEM analyses were also carried out. Results: Dentin permeability decreased after desensitizer application in all groups. Nevertheless, only the difference between ‘Gluma Self Etch Bond’ and ‘Nupro Sensodyne Prophylaxis Paste with Novamin’ groups was significantly different (p<0.05). Dentin permeability increased significantly after post-treatments (p<0.05). There was no statistically difference among the citric acid-subgroups (p>0.05). Of all the artificial saliva-subgroups, only the difference between ‘D/Sense Crystal’ and ‘Bifluorid 12’ was significantly different (p<0.05). In SEM analysis, morphological changes were detected on the dentin surface and within the tubules following desensitizer treatments and post-treatments. Conclusion: All the desensitizers significantly reduced dentin permeability by changing the morphology of the dentin surface and/or dentinal tubules. Following post-treatments, there was some reduction in the efficacy of the desensitizers which was represented by the reduction in permeability values. SEM analysis revealed some physical changes in the dentin structure which can partly give an explanation to the reduced efficacy of tested desensitizers.


2015 ◽  
Vol 12 (1) ◽  
pp. 16-20 ◽  
Author(s):  
N Sathe ◽  
RVS Raju Chakradhar ◽  
V Chandrasekhar

Background Caries process is not a static one, but is dynamic with interspersed periods of demineralization and remineralization of enamel, intimately related and occurs episodically based upon the presence of cariogenic bacteria in dental plaque and the availability of refined carbohydrates for fermentation to organic acids.Objectives Early enamel caries could be reversed with avoidance of frank cavitation. The main objective of this study is to check whether enamel demineralization can be prevented by using the remineralizing agents.Method Forty freshly extracted human central incisors were selected and stored in saline at normal temperature. A window of 3 X 3mm enamel was created and all the specimens were then randomly divided into 4 groups of 10 each. Group I- teeth received no treatment, Group II- teeth treated with Acidulated Phosphate Flouride gel, Group III- teeth treated with Tooth Mousse Plus, Group IV- teeth treated with Remin+. Samples in all the groups were kept in artificial saliva for 24 hours and subjected to modified Ten Cate’s solution at an acidic pH of 3.5 for 10 days. The samples were sectioned and subjected to SEM evaluation.Result Scanning Electron Microscope(SEM) images showed decrease in pore volume of the enamel in all the treatment groups compared to the control group indicating increase in resistance to demineralization in acidic pH.Conclusion The three groups of remineralizing agents, Acidulated Phosphate Fluoride gel, Tooth Mousse Plus and Remin + showed significant increase in fluoride content and negligible increase in calcium content indicating there is remineraliztion.Kathmandu University Medical Journal Vol.12(1) 2014: 16-20


Author(s):  
Ahmad Almehmadi

Abstract The re-use of healing abutments (HAs) has become common practice in implant dentistry for economic concerns and the aim of this in-vitro study was to assess the effect of sodium hypochlorite (NaOCl) in decontamination of HAs. 122 HAs (Used and sterilized n=107; New n=15) were procured from 3 centers, of which 3 samples were discarded due to perforation in sterilization pouch.  For sterility assessment, the used HAs (n=80) were cultured in Brain Heart Infusion Broth (BHI) and Potato Dextrose Agar (PDA), bacterial isolates were identified in 7 samples. Also, 24 used HAs were stained with Phloxine B, photographed and compared to new HAs (n=5). Scanning electron microscope (SEM) assessed the differences between the two sets of HAs, following which the 7 contaminated HAs along with 24 used HAs from staining experiment (Total=31) were subsequently treated with sodium hypochlorite (NaOCl) and SEM images were observed. About 8.75% of HAs tested positive in bacterial culture; Streptococcus sanguis, Dermabacter hominis, Staphylococcus haemolyticus, and Aspergillus species were isolated. Phloxine B staining was positive for used and sterilized HAs when compared to controls. The SEM images revealed deposits in the used HAs and although treatment with NaOCl eliminated the contamination of cultured HAs, the SEM showed visible debris in the HA thread region. This in-vitro study concluded that SEM images showed debris in used HAs at screw-hole and thread regions even though they tested negative in bacterial culture. The treatment with NaOCl of used HAs showed no bacterial contamination but the debris was observed in SEM images. Future studies on the chemical composition, biological implications, and clinical influence is warranted before considering the reuse of HAs.


Author(s):  
Mayson H. Alkhatib ◽  
Dalal Al-Saedi ◽  
Wadiah S. Backer

The combination of anticancer drugs in nanoparticles has great potential as a promising strategy to maximize efficacies by eradicating resistant, reduce the dosage of the drug and minimize toxicities on the normal cells. Gemcitabine (GEM), a nucleoside analogue, and atorvastatin (ATV), a cholesterol lowering agent, have shown anticancer effect with some limitations. The objective of this in vitro study was to evaluate the antitumor activity of the combination therapy of GEM and ATVencapsulated in a microemulsion (ME) formulation in the HCT116 colon cancer cells. The cytotoxicity and efficacy of the formulation were assessed by the 3- (4,5dimethylthiazole-2-yl)-2,5-diphyneltetrazolium bromide (MTT) assay. The mechanism of cell death was examined by observing the morphological changes of treated cells under light microscope, identifying apoptosis by using the ApopNexin apoptosis detection kit, and viewing the morphological changes in the chromatin structure stained with 4′,6-diamidino-2-phenylindole (DAPI) under the inverted fluorescence microscope. It has been found that reducing the concentration of GEM loaded on ME (GEM-ME) from 5μM to 1.67μM by combining it with 3.33μM of ATV in a ME formulation (GEM/2ATV-ME) has preserved the strong cytotoxicity of GEM-ME against HCT116 cells. The current study proved that formulating GEM with ATV in ME has improved the therapeutic potential of GEM and ATV as anticancer drugs.


2016 ◽  
Vol 41 (2) ◽  
pp. 188-193 ◽  
Author(s):  
Eldesouky Heba I. ◽  
Hanno Azza G. ◽  
Bakry Niveen S. ◽  
Ahmed Dawlat M.

2015 ◽  
Vol 40 (5) ◽  
pp. 492-502 ◽  
Author(s):  
GC Oliveira ◽  
AP Boteon ◽  
FQ Ionta ◽  
MJ Moretto ◽  
HM Honório ◽  
...  

SUMMARY Resin-based materials that show promising effects for preventing the progression of erosion have been studied. This in vitro study evaluated the effects of applying resin-based materials, including resin infiltration, on previously eroded enamel subjected to erosive challenges. The influence of enamel surface etching prior to application of the material was also studied. Bovine enamel blocks were immersed in hydrochloric acid (HCl), 0.01 M (pH 2.3), for 30 seconds in order to form a softened erosion lesion. The blocks were then randomly divided into nine groups (n=12) and treated as follows: C = control without treatment; Hel = pit & fissure resin sealant (Helioseal Clear); Adh = two-step self-etching adhesive system (AdheSe); Tet = two-step conventional adhesive system (Tetric N-bond); and Inf = infiltrant (Icon). The Helno, Adhno, Tetno, and Infno groups received the same materials without (or with no) surface conditioning. The depth of the material's penetration into softened erosion lesions was qualitatively analyzed using reflection and fluorescence confocal microscopy. After application of the materials, the blocks were immersed in HCl for two minutes; this step was followed by immersion in artificial saliva for 120 minutes four times a day for five days (erosive cycling). Both the enamel alteration and material thickness were analyzed using profilometry, and the results were submitted to Kruskal-Wallis and Dunn tests (p&gt;0.05). Images from the confocal microscopy showed minimal penetration of Adh/Adhno and deep penetration of Inf/Infno into the erosive lesions. The groups Hel, Adh, Inf, Tetno, and Infno resulted in the formation of a layer of material over the enamel, which was effective in inhibiting the progression of erosion. In conclusion, the infiltrant, with or without etching, was able to penetrate and protect the enamel against dental erosion. The other resin-based materials, except for the two-step conventional adhesive, were able to penetrate and inhibit the progression of erosive lesions only when they were applied after enamel etching.


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