Surface dissolution and degradation of dental resin-based materials with special emphasis by the effects of solvent ethanol, dimethacrylate monomer resin and catalyst solution of ethylene glycol

In today’s modern dentistry, various synthetic materials are used for the replacement or restoration of the missing teeth or parts of teeth structures. These are primarily either polymers or composite materials. The evolution of the synthetic polymers dates back to the use of natural rubbers to poly(methylmethacrylate), (PMMA) to the present-day use of cross-linked copolymers and interpenetrating polymer network (IPN). One commonly used polymer is the group of denture base polymers where polymer beads of poly(methylmethacrylate) and the monomer of methylmethacrylate (MMA) form multiphase polymer system. During the phase of polymerization, some residual MMA monomers are left unconverted and heat-cured however, auto polymerized denture base polymers differ in this respect. In crosslinked dental resins, monomers are typically bis-phenol A-glycidyl methacrylate (bis-GMA) and triethylene glycol dimethacrylate (TEGDMA) or epoxies and they on combination with PMMA form IPN polymer. This study aimed to investigate surface crazing and surface dissolving of dental polymer with solvent and disinfectant ethanol by chemical reaction of transesterification. Scanning electron microscopy, infrared spectroscopy, and Nanoindentation were used as the research methods. The outcomes of the study on various dental polymers suggested that ethanol had a significant influence on affecting the surface roughness, and nanomechanical properties with surface topographical changes of denture base polymers. The effect of ethanol was dependent on time and concentration. Transesterification of the crosslinked bis-GMA based substrate was seen on contrary to the epoxy resin, which did not show signs of transesterification. This was explained by the lack of the ester group in the mainly studied epoxy polymer

Photoactivated disinfection (PAD) of dental root canal system – An ex-vivo study

AbstractAimTo investigate the efficacy of photo activated disinfection (PAD) in reducing colony-forming unit (CFU) counts of Enterococcus faecalis (E. faecalis) in infected dental root canals. The study compared the efficacy of PAD with conventional endodontic treatment (CET) and also a combination of CET along with PAD.Material and Methods53 maxillary incisors were taken for the study. Teeth were divided into 3 groups, CET (Group I) (n=11), PAD (Group II) (n=21), and a combination of CET and PAD (Group III) which consisted of (n=21) samples, Group II and Group III were further divided into 2 subgroups, Group IIa, IIb and Group IIIa, IIIb. Strains of E. faecalis were inoculated in all the root canals. CET group samples were treated by chemo-mechanical preparation (CMP) alone, PAD samples were treated with laser alone at 2 different exposure time (4min and 2min). In the combination treatment, samples were treated initially by CET and then by PAD for a time period of 4min and 2min. Contents of the root canal were aspirated, diluted and plated in Tryptone Soya Broth (TSB) and plates were incubated for 24h to observe the bacterial regrowth.ResultsShowed PAD used along with CMP reduced the bacterial load of E. faecalis by 99.5% at 4min and 98.89% at 2min.ConclusionPAD may be an adjunctive procedure to kill residual bacteria in the dental root canal systems after standard endodontic root canal preparation

The effect of ethanol on surface of semi-interpenetrating polymer network (IPN) polymer matrix of glass-fibre reinforced composite

Aim of the study:The aim of this laboratory study was to evaluate the effect of ethanol treatment on the surfaceroughness (Sa), nano-mechanical properties (NMP) and surface characterization of dentalfiber reinforcedcomposite (FRC) with semi-interpenetrating polymer network (IPN).Materials and methods:A total of 240 FRC specimens with bisphenol A-glycidyl methacrylate - triethyleneglycoldimethacrylate–Poly (methylmetahcrylate) (bis-GMA-TEGDMA-PMMA) IPN matrix system were light cured for40 s and divided into 2 groups (L and LH). The group LH was further post-cured by heat at 95 °C for 25 min. Thespecimens were exposed to 99.9%, 70% and 40% for 15, 30, 60 and 120 s respectively. The treated specimenswere evaluated for Sausing non-contact profilometer. NMP were determined using nanoindentation techniqueand chemical characterization was assessed by Fourier Transform-Infrared (FTIR) spectroscopic analyses.Scanning electron microscopic (SEM) images were made to evaluate the surface topographical changes.Results:Both the L and LH group showed changes in the Saand NMP after being treated by different con-centrations of ethanol and at different time interval. The highest Sawas observed with L-group (0.733μm)treated with 99.9% ethanol for 120 s. Specimens in LH-group treated with 99.9% ethanol for 120 s (1.91 GPa)demonstrated increased nano-hardness, and group treated with 40% ethanol for 120 s demonstrated increasedYoung's modulus of elasticity (22.90 GPa). FTIR analyses revealed changes in the intensity and bandwidth inboth the L and LH groups.Conclusion:The present study demonstrated that both light-cured and heat post-cured FRC were prone forethanol induced alteration in the surface roughness (Sa), nano-mechanical properties (NMP) and chemicalcharacterization. The interphase between the glassfibers and the organic matrix was affected by ethanol. Thechanges were considerably less in magnitude in the heat post-cured FRC specimens.</p

Record Of Natural Enemies Of Few Butterfly Species Amidst Agriculture Ecosystems Of Chamarajanagar District, Karnataka, India

Field studies were carried out by following various standard methods to record the natural enemies of 19 butterfly species during Rabi and Kharif crops amidst agriculture ecosystems of Chamarajanagar District (110401 to 120481 NL and 740521 to 760071 EL) in south Deccan plateau at southern tip of Karnataka State, India. The oviposition and pupation of butterfly species were critically observed for the parasites and predators attack. The death of egg, pupa, larva and adult butterfly species due to parasitoids and spiders was recorded. The parasitoid, Brachymeria jambolana (Hymenoptera: Chalcididae) was more troublesome to the pupa of G. doson and E. core. Around 25 to 27 B. jambolana adult individuals were collected respectively from the pupa of G. doson and E. core. Moreover spider species viz., Selenopes, Zygeilla, Argiope, Hippasa, and Rhene become common predators to 16 butterfly species in this part of the State. Thus, parasitoids and spiders infestation could cause loss to several insect species including protected species like E. core. As natural enemy’s interferences is natural in the wild/open cultivated conditions, it could become one of the major reasons to reduce local butterfly diversity. Hence, there is a dire need to understand about the interaction of parasitoid species with butterfly species which are under threat and whose presence is very essential for the restoration of local biodiversity

Butterfly Diversity at Agri-Horticultural Ecosystems under Tropical conditions of Karnataka, India

Field survey was conducted to record thebutterfly diversity at different agri-horticultural ecosystems of Chamarajanagar district in Karnataka, India by following Visual Count Method (VCM) and Line Transect Method (LTM) during 2012-2013. Ninety five species belong to Nymphalidae, Lycaenidae, Pieridae, Hesperiidae and Papilionidae family members were distributed at various agri-horticultural ecosystems. The density, relative abundance, of butterfly species depended much on safe environmental conditions associated with floral abundance. Further, butterflies were grouped into very common (34), common (28), rare(24) and very rare (09) species found respectively 35.78, 29.47, 25.26 and 9.47%.Altogether, twelve different butterfly species Wildlife Protection Act, 1972. The Nymphalidae family members such as Dark Blue Tiger (Tirumala septentrionis), Blue Tiger (T. limniacea), Double Banded Crow (Euploea Sylvester) and Common Indian Crow (E. core) were migrants, well known for their long distance migration from east to west and vice versa. Since, Chamarajanagar district possess48% reserve forest area including B.R. Hills,M.M. Hills, Gopalswamy Betta and Cauvery Reserve Forest, where human interference is restricted. Perhaps, this might have influencedthe good growth of foraging and nest hostplants amidst Chamarajanagar district for the sebutterfly species

Migratory behaviour of two butterfly species (Lepidoptera: Nymphalidae) amidst agriculture ecosystems of South-Western Karnataka, India

Migratory behavior of Tirumala septentrionis and Euploea species was conducted by employing Visual Count Method amidst agriculture ecosystems at the foot hills of Western Ghats of south-western Karnataka, India during 2013 and 2014. Observations were made on periodicity and pattern of migration, swarm size during different hours of the day. T. septentrionis and Euploea species showed bi-directional viz., north-east and south-west migration respectively during March-April and September to November months. The flight pattern has indicated significant variation between different hours of the days. T. septentrionis swarm was more than that of Euploea species and there existed a significant difference between them. Monsoon become a key factor, influenced the migration of these species. Moreover, local climate and vegetation also played a major role by providing congenial stopover sites during bi-directional migration. Hence, agriculture ecosystems should be taken care to protect the migrating butterfly species

Impact of pesticide application on butterfly fauna at agriculture ecosystems of chamarajanagar district Karantaka India

Field study was conducted to assess quantitatively the impact of pesticides application on native butterfly fauna in agriculture ecosystems at Chamarajanagar District, Karnataka during 2014-2015. Five hundred meter length, 15 permanent line transects (LTs) were randomly selected at paddy growing area (PGA), commercial crops growing area (CCGA) and vegetables growing area (VGA). Around 45 species which belong to the family Hesperiidae (Five species), Lycaenidae (10 species), Nymphalidae (16 species), Papilionidae (Five species) and Pieridae (Nine species) showed considerable variation in their relative density and abundance at areas with pesticides spray compared to control. In general, there was a decline of butterfly fauna at pesticides sprayed areas. The Shannon diversity index varied considerably. Further, the Simpson and Equitability index was more 97 to 98 before application and it was decreased from 95 to 96 after the spray of pesticides. Present study help understand the status of butterfly species survivorship due to pesticides impact amidst intensive agriculture ecosystems

Road mortality of migrant butterflies [nymphalidae: danaianeat] national highway-209 in Chamarajanagar district of Karnataka, India

Systematic survey was conducted to record the road kills of butterflies on the National Highway-209 located amidst agri-horticultural ecosystems by employing Visual Count Method during 2013 at Chamarajanagar District of Karnataka. Total 2,843 butterflies traveled in west-east direction during 21 research hours. The swarm included mainly Tirumala septentrionis (79.2), Euploea sylvester and E. core (20.8). The light vehicles (e.g. Scooters and cars) claimed more butterfly life compared to heavy vehicles (e.g. Bus and lorry) due to catapulation and the death of butterflies indicated significant variation (F=6.48; P>0.01) during different hours of the day. In general, death of young adults and adult T. septentrionis, E. sylvester and E. core was in the ratio 1:0.58 that was followed by male, female and young adults 1:0.65:0.60 ratio. Chamarajanagar District has good road network, national highways located amidst agri-horticultural ecosystems have connectivity with Tamilanadu and Kerala states that could create a barrier during the normal movement of butterflies due to high vehicular traffi

Report on the checklist of butterfly species found at Nagarahole National Park, Karnataka, India

Field investigations were made to record the butterfly species during different seasons at Nagarahole National Park by following standard methods during 2014-2015. Altogether, 138 butterfly species were recorded from 94 genera which belong to five families viz., Hesperiidae, Lycaenidae, Nymphalidae, Papilionidae, Pieridae, whose density, abundance and seasonal distribution varied considerably at NNP. In general, Nymphalidae family members were high (47 species) compared to others. Interestingly, 113 butterfly species were present at all the places by constituting 81.9% and remaining 25 butterfly species (18.1%) were found only at certain places of NNP. A Junonia genus has highest species followed by Papilio and Eurema with five species each. Further, highest butterfly species were observed during the winter and rainy seasons compared to spring and summer. This has instigated to take up further studies amidst NNP for the restoration of butterfly species at their preferred natural habitats

Butterfly species composition and diversity in a protected area of Karnataka, India

Field investigations were made to record the diversity of butterflies at six forest ranges in Nagarahole National Park (NNP), Karnataka during 2014 to 2015. 138 butterfly species were recorded from 94 genera, which belong to five families such as Hesperiidae, Lycaenidae, Nymphalidae, Papilionidae, and Pieridae. Species composition varied significantly (F = 93.85; P < 0.05) among forest ranges in NNP; 113 butterfly species were common at different forest ranges in NNP, but 25 species were confined to specific forest ranges. Nymphalidae had the highest (47) species composition compared to other families. The genus Junonia was represented by six species, followed by Papilio and Eurema with five species each. The Shannon diversity index ranged between 4.49 and 4.59 and the Fisher alpha value ranged between 20.88 and 22.92. The Simpson and Shannon ‘J’ (Equitability) indices were 0.98 and 0.94, suggesting evenness between the six forests ranges. Thus, the present investigation provided insight into the butterflies of NNP and has instigated further research for restoration of forest habitats in NNP