ABSTRACT
The evolution of complex chemical inventory from Darwin's nutrient-rich warm pond necessitated rudimentary yet efficient catalytic folds. Short peptides and their self-organized microstructures, ranging from spherical colloids to amyloidogenic aggregates might have played a crucial role in the emergence of contemporary catalytic entities. However, the question of how short peptide fragments had functions akin to contemporary complex enzymes to catalyze cleavage and formation of highly stable peptide bonds that constitute the backbone of all proteins remains an unresolved yet fundamentally important question in terms of the origins of enzymes. We report short-peptide-based spherical assemblies that demonstrated residue-specific cleavage and formation of peptide bonds of diverse peptide-based substrates under aqueous environment. Despite the short sequence length, the assemblies utilized the synergistic collaboration of four residues which included the catalytic triad of extant serine proteases with a nonproteinogenic amino acid (quinone moiety), to facilitate proteolysis, ligation, and a three-step (hydrolysis-ligation-hydrolysis) cascade. Such short-peptide-based catalytic assemblies argue for their candidacy as the earliest protein folds and open up avenues for biotechnological applications.
Subject(s)
Peptides , Water , Hydrolysis , Peptides/chemistry , Peptides/metabolism , Water/chemistry , Proteolysis , CatalysisABSTRACT
Emergence of complex catalytic machinery via simple building blocks under non-equilibrium conditions can contribute toward the system level understanding of the extant biocatalytic reaction network that fuels metabolism. Herein, we report temporal (dis)assembly of peptide nanostructures in presence of a cofactor dictated by native multistep cascade transformations. The short peptide can form a dynamic covalent bond with the thermodynamically activated substrate and recruit cofactor hemin to access non-equilibrium catalytic nanostructures (positive feedback). The neighboring imidazole and hemin moieties in the assembled state rapidly converted the substrate to product(s) via a two-step cascade reaction (hydrolase-peroxidase like) that subsequently triggered the disassembly of the catalytic nanostructures (negative feedback). The feedback coupled reaction cycle involving intrinsic catalytic prowess of short peptides to realize the advanced trait of two-stage cascade degradation of a thermodynamically activated substrate foreshadows the complex non-equilibrium protometabolic networks that might have preceded the chemical emergence of life.
Subject(s)
Hemin , Nanostructures , Hemin/chemistry , Nanostructures/chemistry , Peptides/chemistry , Catalysis , BiocatalysisABSTRACT
In the early Earth, rudimentary enzymes must have utilized the available light energy source to modulate protometabolic processes. Herein, we report the light-responsive C-C bond manipulation via short peptide-based assemblies bound to the photosensitive molecular cofactor (azo-based photoswitch) where the energy of the light source regulated the binding sites which subsequently modulated the retro-aldolase activity. In the presence of a continual source of high-energy photons, temporal realization of a catalytically more proficient state could be achieved under nonequilibrium conditions. Further, the hydrophobic surface of peptide assemblies facilitated the binding of an orthogonal molecular catalyst that showed augmented activity (promiscuous hydrolytic activity) upon binding. This latent activity was utilized for the in situ generation of light-sensitive cofactor that subsequently modulated the retro-aldolase activity, thus creating a reaction network.
Subject(s)
Earth, Planet , Peptides , Binding Sites , Hydrolysis , Aldehyde-LyasesABSTRACT
Peptide-based biomimetic catalysts are promising materials for efficient catalytic activity in various biochemical transformations. However, their lack of operational stability and fragile nature in non-aqueous media limit their practical applications. In this study, we have developed a cladding technique to stabilize biomimetic catalysts within porous covalent organic framework (COF) scaffolds. This methodology allows for the homogeneous distribution of peptide nanotubes inside the COF (TpAzo and TpDPP) backbone, creating strong noncovalent interactions that prevent leaching. We synthesized two different peptide-amphiphiles, C10FFVK and C10FFVR, with lysine (K) and arginine (R) at the C-termini, respectively, which formed nanotubular morphologies. The C10FFVK peptide-amphiphile nanotubes exhibit enzyme-like behavior and efficiently catalyze C-C bond cleavage in a buffer medium (pH 7.5). We produced nanotubular structures of TpAzo-C10FFVK and TpDPP-C10FFVK through COF cladding by using interfacial crystallization (IC). The peptide nanotubes encased in the COF catalyze C-C bond cleavage in a buffer medium as well as in different organic solvents (such as acetonitrile, acetone, and dichloromethane). The TpAzo-C10FFVK catalyst, being heterogeneous, is easily recoverable, enabling the reaction to be performed for multiple cycles. Additionally, the synthesis of TpAzo-C10FFVK thin films facilitates catalysis in flow. As control, we synthesized another peptide-amphiphile, C10FFVR, which also forms tubular assemblies. By depositing TpAzo COF crystallites on C10FFVR nanotubes through IC, we produced TpAzo-C10FFVR nanotubular structures that expectedly did not show catalysis, suggesting the critical role of the lysines in the TpAzo-C10FFVK.
ABSTRACT
During the billions of years of the evolutionary journey, primitive polymers, involved in proto metabolic pathways with low catalytic activity, played critical roles in the emergence of modern enzymes with remarkable substrate specificity. The precise positioning of amino acid residues and the complex orchestrated interplay in the binding pockets of evolved enzymes promote covalent and non-covalent interactions to foster a diverse set of complex catalytic transformations. Recent efforts to emulate the structural and functional information of extant enzymes by minimal peptide based assemblies have attempted to provide a holistic approach that could help in discerning the prebiotic origins of catalytically active binding pockets of advanced proteins. In addition to the impressive sets of advanced biochemical transformations, catalytic promiscuity and cascade catalysis by such small molecule based dynamic systems can foreshadow the ancestral catalytic processes required for the onset of protometabolism. Looking beyond minimal systems that work close to equilibrium, catalytic systems and compartments under non-equilibrium conditions utilizing simple prebiotically relevant precursors have attempted to shed light on how bioenergetics played an essential role in chemical emergence of complex behaviour. Herein, we map out these recent works and progress where diverse sets of complex enzymatic transformations were demonstrated by utilizing minimal peptide based self-assembled systems. Further, we have attempted to cover the examples of peptide assemblies that could feature promiscuous activity and promote complex multistep cascade reaction networks. The review also covers a few recent examples of minimal transient catalytic assemblies under non-equilibrium conditions. This review attempts to provide a broad perspective for potentially programming functionality via rational selection of amino acid sequences leading towards minimal catalytic systems that resemble the traits of contemporary enzymes.
Subject(s)
Peptides , Proteins , Catalysis , Peptides/chemistry , Substrate SpecificityABSTRACT
Arsenic (As) is considered to be a grave inorganic pollutant, contaminating major aquifers worldwide. In this study, a two-step approach has been designed to combat this toxic metalloid by combining a highly efficient As (III) oxidizing bacteria; Delftia sp. BAs29 and fired red mud pellets to remove the total As from groundwater including both As (III) and As (V) ions. The maximum capacity of As (III) oxidation by Delftia sp. BAs29 was seen to be 95.65% for 500 ml of As contaminated groundwater using an optimized As (III) concentration of 300 ppb and 6.5 g of bacterial cell mass for 7 days. The second step indicated the maximum As (V) adsorption capacity by the stacked red mud pellets to be 97.91% for 500 ml of As contaminated groundwater using the optimized pore size of 106-125 µm for 7 days. The efficiency of As removal increased to 98.76% at a flow rate of 50 ml/h on combining of both the steps. In addition, the morphological properties, chemical composition, and the crystal structure of the As (V) adsorbed red mud pellets were characterized. The techno-economic feasibility of this entire unit was studied using SuperPro 10 software to estimate its optimal demand and potential. Hence, it is believed that scaling up of this two-step bio-filter column can serve as a potent filtration unit to eliminate As, both at the household and industrial level in the near future.
Subject(s)
Arsenic , Delftia , Groundwater , Water Pollutants, Chemical , Water Purification , Arsenic/analysis , Water Pollutants, Chemical/analysis , Groundwater/chemistry , Bacteria , AdsorptionABSTRACT
During fermentation, yeast cells undergo various stresses that inhibit cell growth and ethanol production. Therefore, the ability to tolerate multiple stresses during fermentation is one of the important characteristics for yeast cells that can be used for commercial ethanol production. In the present study, we evaluated the multi-stress tolerance of parent and ethanol adapted Kluyveromyces marxianus MTCC1389 and their relative gene expression analysis. Multi-stress tolerance was confirmed by determining its cell viability, growth, and spot assay under oxidative, osmotic, thermal, and ethanol stress. During oxidative (0.8% H2O2) and osmotic stress (2 M NaCl), there was significant cell viability of 90% and 50%, respectively, by adapted strain. On the other hand, under 45 °C of thermal stress, the adapted strain was 80% viable while the parent strain was 60%. In gene expression analysis, the ethanol stress responsive gene ETP1 was significantly upregulated by 3.5 folds, the osmotic stress gene SLN1 was expressed by 3 folds, and the thermal stress responsive gene MSN2 was expressed by 7 folds. This study shows adaptive evolution for ethanol stress can develop other stress tolerances by changing relative gene expression of osmotic, oxidative, and thermal stress responsive genes.
ABSTRACT
Extant proteins exploit thermodynamically activated negatively charged coenzymes and hydrotropes to temporally access mechanistically important conformations that regulate vital biological functions, from metabolic reactions to expression modulation. Herein, we show that a short amyloid peptide can bind to a small molecular coenzyme by exploiting reversible covalent linkage to polymerize and access catalytically proficient nonequilibrium amyloid microphases. Subsequent hydrolysis of the activated coenzyme leads to depolymerization, realizing a variance of the surface charge of the assembly as a function of time. Such temporal change of surface charge dynamically modulates catalytic activities of the transient assemblies as observed in highly evolved modern-day biocatalysts.
Subject(s)
Amyloid , Polymers , Polymers/chemistry , Catalysis , Amyloid/chemistry , Amyloidogenic Proteins , Coenzymes , PeptidesABSTRACT
Herein, we report the substrate induced generation of a transient catalytic microenvironment from a single amino acid functionalized fatty acid in presence of a cofactor hemin. The catalytic state accessed under non-equilibrium conditions showed acceleration of peroxidase activity resulting in degradation of the substrate and subsequently led to disassembly. Equilibrated systems could not access the three-dimensional microphases and showed substantially lower catalytic activity. Further, the assembled state showed latent catalytic function (promiscuity) to hydrolyze a precursor to yield the same substrate. Consequently, the assembly demonstrated protometabolism by exploiting the peroxidase-hydrolase cascade to augment the lifetime and the mechanical properties of the catalytic state.
Subject(s)
PeroxidaseABSTRACT
The non-scientific disposal of antibiotics has resulted in massive contamination of the bioactive molecules in the aquatic ecosystem. The presence of antibiotics in the effluents limits the biodegradation of micropollutants by affecting the micro-ecological balance. Hence this study aims to remove doxycycline antibiotics from wastewater using biochar. Elemental analysis of the biochar revealed C, Si and N as most abundant content while BET analysis confirmed the mesoporous nature of the adsorbent. The XRD and Raman spectra confirmed amorphic sp2 carbon dominant structure in the biochar. The adsorption mechanism was predicted, correlating the charge distribution and FTIR analysis. The effects of different process parameters were studied using CCD, ANOVA, and RSM. Moreover, the different kinetic models revealed that the pseudo-second-order kinetics model was the best fit and film layer diffusion was the dominant contributor. The isotherm study indicated the high adsorption capacity of the biochar and its non-ionic nature. Thermodynamics study established the spontaneity and exothermic nature. The results suggested no significant change in antibiotic removal efficiency across different system (pond water (97.13%), river water (98.11%), seawater (96.84%), tap water (99.13%), and distilled water (99.74%)). For the desorption of the antibiotic from the biochar surface, 90% ethanol was the most efficient (98.9%), and upon recrystallization by solvent evaporation, 98.7% of the antibiotic of the initial load was recovered. Hence, the implementation of this described process would enable resource recovery along with water treatment, which is not possible with existing approaches. The cost analysis of the whole process revealed that biochar preparation was the bulk expense and the process would be self-sustainable even if the price of the recovered antibiotic would be set at less than half ($41/kg) of the current market price ($94/kg) of the API. Thus, the process endorses a successful circular economy approach toward societal and economic sustainability.
Subject(s)
Anti-Bacterial Agents , Doxycycline , Waste Disposal, Fluid , Water Pollutants, Chemical , Adsorption , Anti-Bacterial Agents/analysis , Anti-Bacterial Agents/chemistry , Charcoal/chemistry , Doxycycline/analysis , Doxycycline/chemistry , Ecosystem , Kinetics , Oryza/chemistry , Water Pollutants, Chemical/analysis , Water Pollutants, Chemical/chemistry , Waste Disposal, Fluid/methodsABSTRACT
In recent years, nucleic acid has emerged as a versatile molecule that has been strategically used in material synthesis and biomedical applications. Keeping in mind the presence of the phosphate group, a glass former in the nucleic acids, we synthesized a transparent glass-like material by the thermal treatment of nucleic acids (DNA and RNA) at 900 °C at atmospheric pressure. Characterization of this material by transmission electron microscopy, X-ray photoelectron spectroscopy, and confocal fluorescence microscopy suggested the presence of in situ-formed nanodiamonds within the phosphate glass matrix. The molecular structure of glass investigated by X-ray photoelectron and infrared spectroscopy indicated a nearly equal proportion of metaphosphates and smaller phosphate units (pyro- and ortho-phosphate) that form the phosphate glass matrix. Thereafter, in vitro biological experiments showed that the nucleic acid-derived glass was non-toxic and cytocompatible, enhanced extracellular matrix secretion, and increased intracellular alkaline phosphatase activity, with potential application in hard tissue engineering. Our work offers insights into nanodiamond synthesis at atmospheric pressure and proves that nucleic acids could be used as a precursor to making an innovative glass-ceramic biomaterial.
ABSTRACT
How modern enzymes evolved as complex catalytic machineries to facilitate diverse chemical transformations is an open question for the emerging field of systems chemistry. Inspired by Nature's ingenuity in creating complex catalytic structures for exotic functions, short peptide-based cross ß amyloid sequences have been shown to access intricate binding surfaces demonstrating the traits of extant enzymes and proteins. Based on their catalytic proficiencies reported recently, these amyloid assemblies have been argued as the earliest protein folds. Herein, we map out the recent progress made by our laboratory and other research groups that demonstrate the catalytic diversity of cross ß amyloid assemblies. The important role of morphology and specific mutations in peptide sequences has been underpinned in this review. We have divided the feature article into different sections where examples from biology have been covered demonstrating the mechanism of extant biocatalysts and compared with recent works on cross ß amyloid folds showing covalent catalysis, aldolase, hydrolase, peroxidase-like activities and complex cascade catalysis. Beyond equilibrium, we have extended our discussion towards transient catalytic amyloid phases mimicking the energy driven cytoskeleton polymerization. Finally, a future outlook has been provided on the way ahead for short peptide-based systems chemistry approaches that can lead to the development of robust catalytic networks with improved enzyme-like proficiencies and higher complexities. The discussed examples along with the rationale behind selecting specific amino acids sequence will benefit readers to design systems for achieving catalytic reactivity similar to natural complex enzymes.
Subject(s)
Amyloid beta-Peptides/chemistry , Amyloid beta-Peptides/metabolism , Biocatalysis , Cytoskeleton/metabolism , Protein Multimerization , Protein Structure, QuaternaryABSTRACT
Wireless controllers have found its application in the supervision of the patients in the hospitals. It is not only a valid issue for the developing countries but also for the developed countries. For this reason, scientists are working on the advancement of medical devices that are capable of decreasing the workload of health caregivers. In this study, the development of an iontophoretic drug delivery device that could be controlled using a mobile is described. For the purpose, hardware and a software module were developed. The hardware module consisted of a two-channel voltage-controlled constant current sources that were used for driving the iontophoretic device. A mobile app was developed to control the two-channel iontophoretic device and to monitor the loose lead of the active and the passive patches. In the case of detection of the loose lead, the specific iontophoretic channel was stopped. Further, the audio-visual indicator was developed for the detection of the detachment of the patches (loose lead). The device was tested in vitro by performing the drug release study using drug-loaded emulsion gels that were formulated.
ABSTRACT
Evaluation of the biological properties of silanized graphene oxide is important in the context of biomedical applications of the material. In this study, we have evaluated the toxicity, immunogenicity and other biological properties like osteogenicity of silanized graphene oxide (SiGO). Graphene oxide (GO) was silanized using a common silanizing agent namely (3-aminopropyl) triethoxysilane (APTES). Silanization was confirmed through infrared spectroscopy and elemental mapping. Post-silanization, we did not observe any significant changes in the morphology of GO. Silanization leads to an increase in the interlayer distance and disorder in the lattice. Study of in vitro toxicity of SiGO on three different cell lines namely primary human dermal fibroblast, murine embryonic fibroblast and human osteosarcoma cell lines revealed that toxicity of SiGO was significantly less than GO. We further showed that in vitro immune activation of macrophage was less in the case of SiGO in comparison to GO. Profiling of osteogenic differentiation of human mesenchymal stem cell revealed that SiGO is less osteogenic than GO. Study of acute toxicity in the murine model indicated that GO was hepatotoxic at experimental concentration whereas SiGO did not show any significant toxicity. This study implied that SiGO is a better biocompatible material than GO.
Subject(s)
Biocompatible Materials/pharmacology , Graphite/pharmacology , Silanes/pharmacology , Adult , Alkaline Phosphatase/metabolism , Animals , Blood Cell Count , Body Weight/drug effects , Cell Cycle/drug effects , Cell Survival/drug effects , Cytoskeleton/drug effects , Cytoskeleton/metabolism , Dermis/cytology , Fibroblasts/drug effects , Graphite/toxicity , Hemoglobins/metabolism , Humans , Mice , NIH 3T3 Cells , Organ Size/drug effects , Osteocalcin/metabolism , Osteogenesis/drug effects , Silanes/toxicity , Spectrometry, X-Ray Emission , Spectroscopy, Fourier Transform Infrared , Spectrum Analysis, Raman , Toxicity Tests , X-Ray DiffractionABSTRACT
INTRODUCTION: It has been well documented that the absence of family support influences the general and oral health of the children. Factors that lead to the development of disease at a given point in time are likely to have their roots in a complex chain of environmental events that may have begun years before. A number of studies have examined the relationship between dental caries and material deprivation and found a positive association between them. Though orphans contribute to 2% of world's population, literature regarding their oral health status is very scarce. This study was carried out with the aim to assess the dental caries status of institutionalized orphan children from Jammu and Kashmir. MATERIALS AND METHODS: A total of 1,664 children that included 1,201 boys and 463 girls from registered orphanages in the state of Jammu and Kashmir were included in the study. Written informed consent was obtained prior to the start of the study; decayed, extracted, filled teeth (deft)/ decayed, extracted, filled surface (defs) and decayed, missing, and filled teeth (DMFT)/decayed, missing, and filled surface (DMFS) indices were used to assess the caries status of primary and permanent dentition. Multiple choice, close-ended questionnaires were administered to assess the oral hygiene habits, knowledge, and dietary behavior of orphan children prior to examination. The study subjects were divided into three groups according to the age of ≤ 6, 7 to 11, and ≥12 years. RESULTS: Results showed that caries prevalence in primary dentition was higher in subjects' ≤6 years of age where the prevalence was 50.9%; in subjects 7 to 11 years of age, the prevalence was 25.2%. Caries prevalence in permanent dentition within the age group 7 to 11 was 69.1%, while in subjects' ≥12 years, the prevalence was 66.2%. Use of toothbrush was the most prevalent method of cleaning the teeth in both the genders, while toothpaste was reported to be the most prevalent material to be used for tooth cleaning followed by tooth-powder. Highest caries prevalence was seen in the subjects using datun sticks as a method to clean their teeth (80.5%). HOW TO CITE THIS ARTICLE: Shah AF, Tangade P, Ravishankar TL, Tirth A, Pal S, Batra M. Dental Caries Status of Institutionalized Orphan Children from Jammu and Kashmir, India. Int J Clin Pediatr Dent 2016;9(4):364-371.
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BACKGROUND: Traumatic dental injuries to anterior teeth are a significant public health problem, not only because their prevalence is relatively high, but also because they have considerable impact on children's daily lives. Traumatic dental injuries (TDIs) cause physical and psychological discomfort, pain and other negative impacts, such as tendency to avoid laughing or smiling, which can affect social relationships. OBJECTIVES: This study aimed to assess the prevalence of traumatic dental injuries to anterior teeth among 12-year-old school children in Kashmir, India. PATIENTS AND METHODS: A cross-sectional study was conducted in private and government schools of India among 1600 schoolchildren aged 12 years. In addition to recording of the type of trauma (using Ellis and Davey classification of fractures, 1970), over jet, Angle's molar relation and lip competence were also recorded. The socioeconomic status and academic performance of the study subjects were registered. The data obtained were compiled systematically and then statistically analyzed. The statistical significance for the association between the traumatic injury and the variables was analyzed using the chi-square test. Logistic regression was used to identify potential risk predictors of TDIs. RESULTS: The overall prevalence of TDI to anterior teeth was found to be 9.3%. The TDI to anterior teeth in male was more than female, but the difference was statistically nonsignificant (P < 0.01). Falls and sports were the most common causes of trauma in the present study. The highest potential risk factor for the occurrence of trauma was over jet. Academic performance was found to be significantly associated to TDI to anterior teeth, when analyzed in a multiple regression model. CONCLUSIONS: It was concluded that the prevalence of traumatic dental injuries was 9.3%. Traumatic dental injuries among children exhibit complex interaction between the victims' oral conditions and their behavior. Therefore, prevention should consider a number of characteristics such as oral predisposing factors, environmental determinants and human behavior. It is recommended that specific and proper public places for leisure and sports activities, with impact-absorbing surfaces around the items on which children are most likely to fall, should be provided.
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OBJECTIVES: The aim of the study was to compare the effect of fifth and seventh generation bonding agent on sealant success. MATERIALS AND METHODS: Sixty-four school children aged six to nine years received sealants in four permanent molars in a split mouth design, such that each patient received sealant in the first permanent molar with fifth generation bonding agent in one arch and seventh generation bonding agent in the other arch; contra-lateral molars were sealed with sealant alone. The evaluation was carried out at baseline, three months, six months and 12 months, according to the criteria by Feigal et al, in 2000. Chi- square test was used to analyze data at P<0.05 level of significance. RESULTS: Statistically significant differences were found for sealant retention between fifth generation and sealant group, and fifth generation and seventh generation groups; whereas, no significant difference was found for sealant retention between seventh generation and sealant group at three, six and 12 months. CONCLUSION: As separate etch and rinse steps are not required for seventh generation bonding agents, and almost similar results were obtained for both sealant and seventh generation groups, it can be concluded that application of sealant along with a seventh generation bonding agent may enhance sealant success and can be used for caries prevention in preventive programs.
ABSTRACT
BACKGROUND: Maintaining good oral hygiene is important to combat periodontal diseases. The use of tooth brush alone does not serve the purpose of removing plaque which demands the use of some adjuncts such as proximal cleaning aids. AIM: The study was conducted to compare the efficacy of Dental Floss and 0.12% Chlorhexidine Gluconate Mouthrinse as an adjunct to toothbrushing on plaque accumulation and gingival inflammation. SETTINGS AND DESIGN: Department of Public Health Dentistry, Kothiwal Dental College and Research Centre, Moradabad, India. This was a randomized, double blind, three-way cross over clinical trial. MATERIALS AND METHODS: Forty five dental students in the age group of 19-25yr. were enrolled into the study. Subjects were randomly assigned into three groups (n=15) i.e. Group A- Toothbrushing with Dental floss (TB+DF), Group B- Toothbrushing with 0.12% Chlorhexidine Gluconate Mouthrinse (TB+CHX-MR) and Group C- Toothbrushing alone (TB Alone) in a three-way crossover manner. After 21 d of trial period, plaque index (PI) and gingival index (GI) were assessed for each group, oral prophylaxis followed by a washout period for 14d. STATISTICAL ANALYSIS USED: Mean, standard deviations and p-values were obtained. ANOVA test was used to compare the intergroup difference and Post hoc test to compare between the two groups. RESULTS: The inter-group comparison for GI and PI at all interventions showed statistically significant difference (p<0.001). While comparing between group A and group C at second and third follow up, no significant difference were observed though group A showed reduction in mean values for both the clinical parameters whereas while comparing between group A and group B, statistically significant difference was observed, which is in line when compared with group B and group C. The Group B showed more reduction in plaque and gingival scores which was found to be statistically significant (p<0.001). CONCLUSION: CHX-MR when used as an adjunct to toothbrushing is more effective in the reduction of plaque and gingival scores than a toothbrush alone or in combination with DF.
ABSTRACT
BACKGROUND: Toothbrushes are over-the-counter products; therefore, no special instruction is given to users when they purchase. There are scarce published studies that have investigated about how often toothbrushes should be replaced. Thus, this study aimed to verify the impact of the Progressive Toothbrush Bristle Flaring on plaque control efficacy of toothbrush. MATERIALS AND METHODS: Thirty six subjects were randomly selected and underwent complete oral prophylaxis 10 days prior to the Baseline plaque recording. All subjects were provided with new similar toothbrushes and were divided into two groups. New Brush Group changed toothbrush every month and Old month Group used single toothbrush for the whole period of the study. Both groups were assessed for plaque accumulation every month using Turesky et al, (1970) modification of the Quigley and Hein (1962) plaque index. Toothbrush head was photographed and assessed by measuring the brushing surface area on standardized photographs using National Institutes of Health Image Analysis Program (USA). RESULTS: Both groups showed similar plaque scores at the 40(th) day; progressive increase in the plaque scores in group without changing the toothbrush were recorded at the 70(th) and 100(th) days. As toothbrush flaring increased, the plaque scores also increased in the Old Brush Group. Highest plaque accumulation was recorded in Mandibular Lingual aspects in Old Brush Group. CONCLUSION: Progressive increase was seen in the plaque scores with increase in toothbrush bristle flaring.
Subject(s)
Dental Plaque Index , Oral Hygiene/methods , Toothbrushing/instrumentation , Adult , Equipment Design , Female , Humans , Male , Oral Hygiene/instrumentation , Prospective Studies , United States , Young AdultABSTRACT
BACKGROUND: Supernumerary teeth are developmental anomaly. There are various theories explaining their occurrence. Maxilla is more commonly affected and males have higher predilection than females for having supernumerary teeth. CASE DETAILS: The present case is presented with three permanent central incisors, all of them with normal morphology. On clinical and radiographic examination, it was identified as a case of non-syndromic unilateral left supplemental maxillary central incisor. Treatment plan involved extraction of the supplemental tooth followed by orthodontic treatment to correct the malalignment of the teeth. CONCLUSION: The presence of supplemental teeth of normal morphology is quite a rare condition and are commonly associated with various syndromes but, in rare cases, they also exists as non-syndromic forms. Supernumerary teeth can cause aesthetic or functional problems, especially when situated in the maxillary anterior region. Complications related to the phenomenon can be minimized by early detection and by carrying out a comprehensive treatment protocol.