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1.
Front Psychiatry ; 14: 1214603, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38025468

RESUMEN

Though literacy levels are slowly improving in India due to the steps taken by the Government of India, it has been a challenge for female students with gender disparities in literacy levels. Stress levels are high in students, more so during their exam times. While prior literature has demonstrated the prevalence of stress during student life, there is limited evidence of any interventions to decrease stress and improve satisfaction with life, specifically for female students. Heartfulness meditation is a heart-based meditation practice that may reduce stress and improve satisfaction with life among female students. We conducted a prospective cohort analysis comparing perceived stress and satisfaction with life outcomes among female students who self-selected to participate in the Heartfulness meditation program. The first group, G20, underwent intervention from week 0 until week 12 and continued their practice independently until week 20. The second group, G14, joined the intervention from week 7 until week 12 with only a 6-week exposure to guided meditation sessions through Heartfulness Trainers. They continued their practice independently until week 20. Data on Perceived Stress (PSS) and Satisfaction with Life (SWLS) were collected at week 0 and week 20 for both groups. G20 had 127 participants, and G14 had 113 participants. Ninety-four participants from the G20 group and 93 from G14 completed the study. The G20 group showed a statistically significant reduction of PSS scores from 20.79 to 18.96, and an increase in the SWLS scores from 22.03 to 23.51 from baseline to the end of the study period. The study of the Pearson correlation coefficient indicated that there is a weak positive correlation between pre- and post-scores for both the groups for both PSS and SWLS. Our findings suggest that Heartfulness meditation practice offers significant benefits with perceived stress and satisfaction with life among female students independent of their age. Still, a prolonged guided intervention of over 6 weeks is needed. A larger, randomized study with an additional control group with no meditation intervention is recommended. Clinical trial registration: ISRCTN11302156, https://doi.org/10.1186/ISRCTN11302156.

2.
J Indian Prosthodont Soc ; 20(2): 162-170, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32655220

RESUMEN

AIM: The aim of this study was to examine systematically the data published on the cost and cost-effectiveness of mandibular two-implant-retained overdentures compared to other removable prosthodontic treatment options for edentulous mandible. SETTINGS AND DESIGN: It is a systematic review which analyses the available data from the prospective and retrospective studies and randomized clinical trials to find out costs and cost effectiveness of different removable treatment modalities for completely edentulous mandible. The study protocol was decided according to PRISMA guidelines. MATERIALS AND METHODS: The search was limited to English literature only and included an electronic search through PubMed Central, Cochrane Central Register of Controlled Trials, and complemented by hand-searching. All clinical trials published up to August 2019 were included (without any starting limit). Two independent investigators extracted the data and assessed the studies. STATISTICAL ANALYSIS USED: No meta-analysis was conducted because of the high heterogeneity of data. RESULTS: Out of the initial 509 records, only nine studies were included. The risks of bias of individual studies were assessed. Six studies presented data on cost and cost analysis only. The rest three articles provided data on cost-effectiveness. The overall costs of implant overdentures were higher than the conventional complete dentures. However, implant overdentures were more cost-effective when compared to conventional complete dentures. Single-implant overdentures are also less expensive than two-implant overdentures. Overdentures supported by two or four mini-implants were also reported as more cost-effective than conventional two-implant-supported overdentures. CONCLUSIONS: Two-implant-retained overdentures are more expensive but cost-effective than the conventional complete dentures. Two- or four-mini-implant-retained overdentures are less expensive than two-implant-retained overdentures, but there is a lack of long-term data on aftercare cost and survival rate of mini-implants. Single-implant overdentures are also less expensive than the two-implant-retained overdentures. The differences of the aftercare costs of different attachment systems for implant overdentures were not significant. There is a need of further studies on comparative cost-effectiveness of different types of implant overdentures.

3.
Sci Rep ; 10(1): 4960, 2020 03 18.
Artículo en Inglés | MEDLINE | ID: mdl-32188919

RESUMEN

Pigeonpea is the second most important pulse legume crop for food and nutritional security of South Asia that requires accelerated breeding using high throughput genomic tools. Single nucleotide polymorphisms (SNPs) are highly suitable markers for this purpose because of their bi-allelic nature, reproducibility and high abundance in the genome. Here we report on development and use of a pigeonpea 62 K SNP chip array 'CcSNPnks' for Affymetrix GeneTitan® platform. The array was designed after filtering 645,662 genic-SNPs identified by re-sequencing of 45 diverse genotypes and has 62,053 SNPs from 9629 genes belonging to five different categories, including 4314 single-copy genes unique to pigeonpea, 4328 single-copy genes conserved between soybean and pigeonpea, 156 homologs of agronomically important cloned genes, 746 disease resistance and defense response genes and 85 multi-copy genes of pigeonpea. This fully genic chip has 28.94% exonic, 33.04% intronic, 27.56% 5'UTR and 10.46% 3'UTR SNPs and incorporates multiple SNPs per gene allowing gene haplotype network analysis. It was used successfully for the analysis of genetic diversity and population structure of 95 pigeonpea varieties and high resolution mapping of 11 yield related QTLs for number of branches, pod bearing length and number of seeds per pod in a biparental RIL population. As an accurate high-density genotyping tool, 'CcSNPnks' chip array will be useful for high resolution fingerprinting, QTL mapping and genome wide as well as gene-based association studies in pigeonpea.


Asunto(s)
Cajanus/genética , Cromosomas de las Plantas/genética , Genes de Plantas , Análisis de Secuencia por Matrices de Oligonucleótidos/métodos , Fitomejoramiento/métodos , Polimorfismo de Nucleótido Simple , Sitios de Carácter Cuantitativo , Cajanus/crecimiento & desarrollo , Mapeo Cromosómico , Genotipo , Repeticiones de Microsatélite , Fenotipo
4.
BMC Genomics ; 20(1): 333, 2019 May 02.
Artículo en Inglés | MEDLINE | ID: mdl-31046663

RESUMEN

BACKGROUND: Helminth infections affect ~ 60% of the human population that lives in tropical and subtropical regions worldwide. These infections result in diseases like schistosomiasis, lymphatic filariasis, river blindness and echinococcosis. Here we provide a comprehensive computational analysis of the aminoacyl tRNA synthetase (aaRS) enzyme family from 27 human-infecting helminths. Our analyses support the idea that several helminth aaRSs can be targeted for drug repurposing or for development of new drugs. For experimental validation, we focused on Onchocerciasis (also known as "river blindness"), a filarial vector-borne disease that is prevalent in Africa and Latin America. We show that halofuginone (HF) can act as a potent inhibitor of Onchocerca volvulus prolyl tRNA synthetase (OvPRS). RESULTS: The conserved enzyme family of aaRSs has been validated as druggable targets in numerous eukaryotic parasites. We thus embarked on assessing aaRSs from the genomes of 27 helminths that cause infections in humans. In order to delineate the distribution of aaRSs per genome we utilized Hidden Markov Models of aaRS catalytic domains to identify all orthologues. We note that Fasciola hepatica genome encodes the highest number of aaRS-like proteins (69) whereas Taenia asiatica has the lowest count (32). The number of genes for any particular aaRS-like protein varies from 1 to 8 in these 27 studied helminths. Sequence alignments of helminth-encoded lysyl, prolyl, leucyl and threonyl tRNA synthetases suggest that various known aaRS inhibitors like Cladosporin, Halofuginone, Benzoborale and Borrelidin may be of utility against helminths. The recombinantly expressed Onchocerca volvulus PRS was used as proof of concept for targeting aaRS with drug-like molecules like HF. CONCLUSIONS: Systematic analysis of unique subdomains within helminth aaRSs reveals the presence of a number of non-canonical domains like PAC3, Utp-14, Pex2_Pex12 fused to catalytic domains in the predicted helminth aaRSs. We have established a platform for biochemical validation of a large number of helminth aaRSs that can be targeted using available inhibitors to jump-start drug repurposing against human helminths.


Asunto(s)
Aminoacil-ARNt Sintetasas/genética , Genoma de los Helmintos , Genómica/métodos , Proteínas del Helminto/genética , Helmintiasis/genética , Helmintos/genética , Helmintos/aislamiento & purificación , Animales , Helmintiasis/parasitología , Helmintos/clasificación , Humanos , Filogenia
5.
J Indian Prosthodont Soc ; 18(4): 343-355, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30449963

RESUMEN

CONTEXT: Altered orofacial morphology and poor dental status affects the dietary intake of cleft patient, making susceptible to nutritional imbalance. Oral health care planning for this population is impossible without the evaluation of stomatognathic functional status as well as prosthetic and nutritional status and need. AIMS: The aim of this study was to evaluate prosthetic status and prosthetic treatment need, bite force and nutritional status, in adult cleft patients and to compare them with the adult noncleft population of similar definition. SETTINGS AND DESIGN: Cleft (n = 250) and noncleft (n = 250) individuals of either sex, aged 18 years or above, excluding severe medically compromised and differently abled, were examined and individual biteforce was measured after obtaining written consent and ethical clearance from the two institutions in Kolkata. SUBJECTS AND METHODS: A "raw data sheet" was prepared according to the parameters of the "Oral Health Surveys: Basic methods," World Health Organization (1997) for evaluation of prosthetic status and need, dentition status and Mini-Nutritional Assessment, Nestlé (1994) for the evaluation nutritional status. A Gnathodynamometer was used to record bite force. STATISTICAL ANALYSIS USED: Statistical analysis was performed using SPSS 20.0.1, Graph Pad Prism version 5, Student's t-test, and Chi-square test. RESULTS: The mean bite force of frontal area in cleft group (3.4356 ± 0.9457 kgf) was found to be significantly lower (P < 0.0001) than in noncleft (22.8749 ± 5.3644 kgf) group. The difference of mean bite force in the right side (2.4576 ± 0.6131 kgf) and left side (1.2708 ± 0.1036 kgf) in cleft group was found to be statistically significant (P < 0.0001). Prosthetic need in maxillary arch was found to be significantly (χ2: 490.0000; P < 0.0001) higher in cleft than in noncleft group. Nutritional status was observed to be significantly (χ2: 179.4049; P < 0.0001) higher "at risk" in cleft than in noncleft group. CONCLUSIONS: Lack of adequate Government concern leading to significantly higher prosthetic need and lower prosthetic status, hence lower bite force resulting lower nutritional status in adult cleft patients in Kolkata.

6.
J Indian Prosthodont Soc ; 18(3): 263-270, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30111916

RESUMEN

CONTEXT: Determination of horizontal condylar guidance (HCG) by various clinical and radiographic methods was performed by several investigators. If a correlation between HCG values using lateral radiographic tracing and protrusive interocclusal records can be established, the necessity of performing elaborate recording procedures can be eliminated. AIMS: The aim of this study is to evaluate and to compare the correlation between HCG values in edentulous people using the protrusive interocclusal records mounted on a semi-adjustable articulator with the manual tracing of panoramic radiograph and lateral cephalogram. MATERIALS AND METHODS: A total of 20 completely edentulous individuals of either sex from 45 to 75 years (mean age 63.15 years) fulfilling the inclusion criteria were included in this in vivo study. In all the participants, HCG angles were determined clinically using protrusive interocclusal records and semi-adjustable articulator after intraoral gothic arch tracing. Radiographically, it was obtained by cephalometric tracing of panoramic radiograph and lateral cephalogram. RESULTS: The present study shows mean HCG ± standard deviation (SD) of 28.17° ± 5.99° for interocclusal protrusive record while cephalometric tracing method yielded HCG ± SD of 38.95° ± 4.77° and 35.2° ± 4.94° for lateral cephalogram and orthopantomogram, respectively. A statistically significant positive correlation (P < 0.0001) was found among these three methods. CONCLUSION: HCG can be successfully determined in edentulous participants by using three aforementioned methods. HCG values from cephalometric tracing of diagnostic radiographs can be used as an adjunct to the clinical method but cannot be used independently for programming a semi-adjustable articulator.

7.
J Indian Prosthodont Soc ; 18(1): 53-60, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29430143

RESUMEN

AIMS: This study aims to find the effect of change in different salivary factors before and after complete denture insertion and to measure the maxillary denture retention in different arch forms. MATERIALS AND METHODS: Thirty completely edentulous individuals (10 each of square, tapered, and ovoid arch form of maxilla) belonging to the age group of 40-70 years were selected. Salivary factors (flow, density, pH, viscosity, and total protein) were evaluated before and after denture insertion. Retention of maxillary denture was measured in all the different arch forms. STATISTICAL ANALYSIS: Student's independent sample's t-test was applied. The correlation was analyzed by Pearson's correlation analysis. RESULTS: While mean flow rate and pH of saliva increased, mean viscosity, total protein, and density of saliva decreased after maxillary complete denture insertion. A positive correlation was found between retention and total maxillary basal surface area. Retention value was found to be greatest in square type and least in tapered type. CONCLUSIONS: Complete denture acts as a mechanical stimulant thus increasing flow rate and pH immediately after complete denture insertion. Density, total protein, and viscosity of saliva decreased after complete denture insertion which may be due to increase in water content of saliva. The retention of maxillary complete denture does not seem to depend on the rate of change of the salivary factors, before and after complete denture insertion. Total basal surface area and maxillary denture retention values were highest in square arch form and least in tapered arch form.

8.
Structure ; 25(10): 1495-1505.e6, 2017 10 03.
Artículo en Inglés | MEDLINE | ID: mdl-28867614

RESUMEN

Developing anti-parasitic lead compounds that act on key vulnerabilities are necessary for new anti-infectives. Malaria, leishmaniasis, toxoplasmosis, cryptosporidiosis and coccidiosis together kill >500,000 humans annually. Their causative parasites Plasmodium, Leishmania, Toxoplasma, Cryptosporidium and Eimeria display high conservation in many housekeeping genes, suggesting that these parasites can be attacked by targeting invariant essential proteins. Here, we describe selective and potent inhibition of prolyl-tRNA synthetases (PRSs) from the above parasites using a series of quinazolinone-scaffold compounds. Our PRS-drug co-crystal structures reveal remarkable active site plasticity that accommodates diversely substituted compounds, an enzymatic feature that can be leveraged for refining drug-like properties of quinazolinones on a per parasite basis. A compound we termed In-5 exhibited a unique double conformation, enhanced drug-like properties, and cleared malaria in mice. It thus represents a new lead for optimization. Collectively, our data offer insights into the structure-guided optimization of quinazolinone-based compounds for drug development against multiple human eukaryotic pathogens.


Asunto(s)
Aminoacil-ARNt Sintetasas/química , Inhibidores Enzimáticos/administración & dosificación , Infecciones por Protozoos/tratamiento farmacológico , Quinazolinonas/administración & dosificación , Aminoacil-ARNt Sintetasas/antagonistas & inhibidores , Animales , Dominio Catalítico/efectos de los fármacos , Coccidiosis/tratamiento farmacológico , Criptosporidiosis/tratamiento farmacológico , Descubrimiento de Drogas , Inhibidores Enzimáticos/química , Inhibidores Enzimáticos/farmacología , Humanos , Leishmaniasis/tratamiento farmacológico , Malaria/tratamiento farmacológico , Ratones , Modelos Moleculares , Proteínas Protozoarias/antagonistas & inhibidores , Proteínas Protozoarias/química , Quinazolinonas/química , Quinazolinonas/farmacología , Relación Estructura-Actividad , Toxoplasmosis/tratamiento farmacológico
9.
J Indian Prosthodont Soc ; 17(2): 175-182, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28584419

RESUMEN

CONTEXT: Many authors have conducted studies that determine horizontal condylar guidance (HCG) using various methods, articulator systems, and recording materials. However, there is a dearth of literature on variability existing in HCG in individuals with different skeletal relationships. This study is an attempt to verify whether such a difference exists or not. AIMS: The aim of this study is to determine and correlate the HCG in individuals with Angle's Class I, Class II, and Class III malocclusion using radiographic and clinical methods. SETTINGS AND DESIGN: HCG was recorded for thirty individuals, ten of each class. For each individual, HCG was recorded clinically as well as radiographically. SUBJECTS AND METHODS: Clinically, HCG was recorded using protrusive check bites and a semi-adjustable articulator. Radiographically, two methods were employed. First, a "tangent method" wherein the angle made by a tangent to the posterior slope of articular eminence with the Frankfurt horizontal (FH) plane was considered as the HCG, and second, a "protrusive method" where the position of the condyle at maximum intercuspation and 6 mm protrusion were traced, and the angle this path made with the FH plane was recorded as the HCG. STATISTICAL ANALYSIS: Descriptive statistical analysis along with Tukey's test and analysis of variance was used to calculate and compare the mean values. Pearson correlation coefficient was used to establish correlation between various means. RESULTS: A significant difference in the HCG of three skeletal relationships was seen, with Class II having a steeper angle than the other two. Among the various methods used, a correlation was found between the clinical and the protrusive method; however, the tangent method yielded greater values of HCG. CONCLUSIONS: The average value of HCG should not be used as it differs according to the skeletal relationship. Radiographic method can be used to yield consistent HCG; however, the protrusive method should be employed.

10.
Contemp Clin Dent ; 7(3): 336-42, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27630498

RESUMEN

CONTEXT: This study evaluated the efficacy of denture adhesive, cleanser, chlorhexidine, and brushing against Candida albicans biofilm developed on an acrylic surface and predicted the most effective, simple, and inexpensive way to maintain denture health, thereby preventing denture stomatitis. AIMS: To find the best possible method for maintaining denture hygiene. SETTINGS AND DESIGN: This retrospective analysis was conducted in the Guru Nanak Institute of Dental Sciences and Research, Kolkata, and this in vitro study was designed to minimize denture stomatitis among denture wearing population. SUBJECTS AND METHODS: Sixty acrylic discs of equal dimensions after exposure to C. albicans were treated for a duration of 24 h with denture adhesive, cleanser, 0.2% chlorhexidine individually, or in combinations simulating clinical conditions dividing in six groups, ten samples each (n = 10). STATISTICAL ANALYSIS USED: After treatment, colony count was evaluated and statistically analyzed by post hoc Tukey's test and Dunnett's test to determine the most effective way of prevention. RESULTS: The statistical post hoc analysis (Tukey's test and Dunnett's test) showed high significance (P < 0.0001). The group treated with adhesive showed high fungal growth compared to the control group, whereas chlorhexidine showed high potency to prevent C. albicans, whereas adhesive increased the adhesion of C. albicans to acrylic surface. CONCLUSIONS: Denture adhesive increases the adherence of C. albicans to denture surface. Other cleaning chemicals such as cleanser and chlorhexidine decrease the adherence. Moreover, among the all denture cleaning protocol, chlorhexidine drastically inhibit the adherence, as well as growth of C. albicans over denture surface.

11.
J Struct Funct Genomics ; 17(2-3): 51-6, 2016 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-27400688

RESUMEN

Mutations in Plasmodium falciparum gene kelch13 (pfkelch13) are strongly and causally associated with resistance to anti-malarial drug artemisinin, but their effects on PfKelch13 structure and function remain unclear. Utilizing the publicly available three-dimensional structure of PfKech13 (PDB ID: 4yy8), we find that most of the mutations in its propeller domain occur in two spatial clusters. Of these, one cluster is enriched in surface exposed residues which may drive PfKelch13-centered protein interactions, and the second cluster mostly contains residues which are buried and whose mutations may destabilize PfKelch13 structure. The most prevalent resistant mutations C580Y and Y493H are distal from the above two clusters. The C580Y mutation creates sterically unfavourable contacts while Y493H possibly alters the hydrophobic core of the propeller domain. These analyses will facilitate further experimental studies aimed at understanding how mutations in pfkelch13 lead to artemisinin resistance.


Asunto(s)
Artemisininas , Bases de Datos de Proteínas , Resistencia a Medicamentos , Lactonas , Malaria Falciparum , Mutación , Plasmodium falciparum , Proteínas Protozoarias , Humanos , Plasmodium falciparum/química , Plasmodium falciparum/genética , Proteínas Protozoarias/química , Proteínas Protozoarias/genética
12.
J Prosthet Dent ; 116(2): 200-205.e1, 2016 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-27038528

RESUMEN

STATEMENT OF PROBLEM: No cost-effective method of ascertaining bone density from 2-dimensional radiographic images is currently available for dental implants before surgery. PURPOSE: The purpose of this in vivo study was to use digital panoramic radiology and dental computed tomography (CT) to evaluate the bone density of specific points in the jaw near the tooth-bearing areas. The objective was to determine whether digital panoramic radiology can be used in assessing bone density as an alternative to a more expensive and complex dental CT. MATERIAL AND METHODS: This study involved determining bone densities at predetermined anatomic landmarks near tooth-bearing areas of the jaws of 20 participants, using digital panoramic radiology in gray-level scale with a lead step wedge. Subsequently, the bone densities of the same points were determined in Hounsfield units (Hu) with dental CT. The data collected after interpretation of the panoramic radiograph and CT were tabulated and analyzed statistically. RESULTS: Bone density measured using CT correlated with the first 3 steps of (A, B, and C) the digital scale of gray. Further analysis conducted using the Mann-Whitney U test showed a significant association between step A to detect D4 bone, step B to detect D3 bone, and step C to detect D2 type bone. CONCLUSIONS: The digital scale of gray obtained from a lead step wedge can be effectively used with digital orthopanoramic radiology to assess bone density before the placement of implants, but with certain restrictions.


Asunto(s)
Densidad Ósea/fisiología , Mandíbula/diagnóstico por imagen , Maxilar/diagnóstico por imagen , Radiografía Dental Digital , Radiografía Panorámica , Implantación Dental Endoósea , Implantes Dentales , Humanos , Mandíbula/fisiología , Maxilar/fisiología , Tomografía Computarizada Multidetector , Cuidados Preoperatorios
13.
J Indian Prosthodont Soc ; 15(4): 318-25, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26929534

RESUMEN

AIM: This study includes a comparative evaluation of the various surface treatments of the intaglio surface of crowns in combination with various luting agents for maximal retention. MATERIALS AND METHODS: Totally, 150 dies of a standard complete crown preparation were fabricated. Wax pattern with a loop on the occlusal surface was prepared on each die using standard procedures, and then crowns were cast with nickel-chromium alloy. These crowns were randomly divided into five groups as per the surface of the intaglio surface of the metal copings. The crowns in each group were again subdivided randomly into three groups as per the luting agents used resin-modified glass ionomer cement, glass ionomer cement, and zinc phosphate cement. Retention was measured (MPa) by separating the metal crowns from the metallic die under tension on a Universal testing machine. STATISTICAL ANALYSIS USED: The data were recorded and statistically analyzed using one-way analysis of variance followed by Tukey's test. RESULTS: The retention differed both with surface treatment and type of luting agents. Untreated group showed the least bond strengths < sandblasting with 50 µm alumina < sandblasting with 50 µm alumina with ultrasonic cleaning < sandblasting with 110 µm alumina < sandblasting with 110 µm alumina along with ultrasonic cleaning. For luting agents, glass ionomer cement showed least bond strength because there was no chemical bonding present between metal crown and metallic die, followed by zinc phosphate cement and maximum bond strength were found for resin-modified glass ionomer cement. CONCLUSION: Among all types of surface treatments used in this study, maximum bond strength was yielded by sandblasting with 110 µm alumina + ultrasonic cleaning and the best luting agent was resin-modified glass ionomer cement.

14.
J Indian Prosthodont Soc ; 14(3): 262-72, 2014 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-25183910

RESUMEN

The availability of adhesive primers capable of bonding chemically to base metal alloys without well defined passive oxide surface film has been improved significantly over the last decade. Therefore, the purpose of the study was to compare and evaluate the effect of metal primer on adhesion of heat cure acrylic resin to cast titanium. Shear bond strength test was conducted on 80 commercially pure titanium cast metal heat-cure acrylic resin discs treated with different surface treatments. The first group received no surface treatment (group I); the second group was subjected to sandblasting (group II); the third group was treated with bonding agent (alloy primer) (group III) and the fourth was treated with sandblasting and alloy primer (group IV). After the samples were surface treated, acrylic resin was mixed, packed and processed over the test area of cast titanium. Ten specimens of each group were immersed in distilled water for 24 h followed by thermocycling for 20,000 cycles. Shear bond-strength between the heat cure acrylic resin and titanium was evaluated using Instron universal testing machine. Debonded specimens of all the groups were subjected to SEM analysis. The bond failure (MPa) was analyzed by ANOVA and Duncan's multiple comparison tests. Surface treatment with sandblasting, followed by the application of alloy primer showed maximum shear bond strength before and after thermocycling (24.50 ± 0.59 and 17.39 ± 1.56 MPa respectively).The bond strength values are found to be in decreasing magnitudes as group IV > group III > group II > group I. The following pretreatment to improve the shear bond strength of heat cure acrylic resin to titanium is recommended in order to attain the maximum bond strength in cast titanium frameworks for various prostheses: sandblasting, cleaning in an ultrasonic bath for 10 min and air drying followed by application of a bonding agent uniformly on the sandblasted cast titanium surface before packing with heat cure acrylic resin.

15.
J Indian Prosthodont Soc ; 13(4): 578-86, 2013 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-24431795

RESUMEN

Dental impressions, contaminated with saliva, blood, plaque, are potential source of infection. All impressions should be disinfected after their removal from mouth to prevent cross contamination. Different methods have been tried to disinfect the commonly used irreversible hydrocolloid impression material, but they have been shown to influence the dimensional stability and surface detail of the impression which ultimately affects the precision of the final prosthesis. The aim of this study was to evaluate the efficacy of pre-procedural oral prophylaxis and mouthrinses in reducing the overall microbial load intraorally as well as on alginate impression surface. A total of 60 positive cases selected from 100 subjects who were partially edentulous and above 18 years of age and without medical or pharmacotherapy histories were studied over a period of 18 months, from outpatient clinic of Department of Prosthodontics, GNIDSR. Alginate impressions, before and after prophylaxis were examined microbiologically for the persistence of test microorganisms on the untreated (control group) and the impressions made after treatment. The data were statistically analyzed by the Student t test to assess the effectiveness of the procedure and also the comparative effectiveness of oral prophylaxis and commonly used mouthrinses. The results showed that the impressions were safer when made after oral prophylaxis and/or mouthrinses.

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