Role of MgF2 addition on high energy ball milled kalsilite:Implementation as dental porcelain with low temperature frit

Porcelain fused to metal(PFM)has received great attention over the last few years due to its importance in the dentistry.Kalsilite(K_(2)O·Al_(2)O_(3)·SiO_(2))is a high thermal expansion porcelain,suitable for bonding to metals.However,kalsilite is a metastable phase which gets converted into crystalline leucite upon heating.In the current work feasibility of developing stable kalsilite phase,dispersion of MgF2 in it as an additive and using mechanochemical synthesis are studied.Micro fine dental material has been formulated by mixing prepared kalsilite with low temperature frit(LTF)in different ratio.The crystalline phases evolved in fired powders are characterized by powder X-ray diffraction(XRD)technique.Kalsilite with different ratio of LTF has been cold pressed and heat treated to examine its coefficient of thermal expansion(CTE),flexural strength,apparent porosity(AP),bulk density(BD)and microstructure.Results indicate that MgF_(2) addition and high milling duration help in kalsilite stabilization.Temperature also plays an important role in this stabilization,and at 1100℃single phase kalsilite formation is observed.Present outcomes demonstrate that it is easily possible to synthesize a stable single phase kalsilite with desirable properties.

Enzyme inhibition by molluscicidal agents of Bauhinia variegata and Mimusops elengi in the nervous tissue of Lymnaea acuminata

Objective:To evaluate the effect of enzymatic activity in the nervous tissue of snail Lymnaea acuminata(L.acuminata)by Bauhinia variegata(B.variegata)and Mimusops elengi(M.elengi)and their active molluscicidal components quercetin and saponin.Methods:Treatment of sublethal concentration(40%and 80%of 96-h LC_(50))in vivo of column-purified fraction of B.variegata leaf and M.elengi bark and their molluscicidal agents quercetin and saponin inhibit the acetylcholinesterase(AChE),acid and alkaline phosphatase(ACP and ALP)activities in the nervous tissue of L.acuminata.Results:AChE activity was more inhibited than ACP and ALP in snail exposed to column-purified fraction of M.elengi bark and saponin.Among all the treatments the highest inhibition in AChE activity(27.77%)was noted in snail L.acuminata exposed to 80%of 96-h LC_(50)of saponin at 96-h exposure period.Conclusions:It can be concluded from the present study that inhibition of AChE,ACP and ALP by B.variegata leaf(quercetin)and M.elengi bark(saponin)in snail L.acuminata could be the cause of snail mortality.