In Vitro Sustained Release of Calcium Ions And

8/6/2019 In Vitro Sustained Release of Calcium Ions And

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Nidambur Vasudev Balla

Gopal Venktesh Shavi,Ranjith Kumar,

Mala Kundabala.


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y Calcium hydroxide used -1920s.

y Introduced by Hermann.

clinical applications

y an antimicrobial agent,

y controlling exudates from root canals,

y arresting inammatory root resorption,

y inducing calcic response,

y root canal sealer.


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y MOA

By dissociating into calcium and hydroxyl ions

increasing pH locally (Tronstad et al) .


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Benecial effect is due to

y Break up of fatty acids in gram-negative bacteria,

y inactivation of endotoxins,

y damage to the bacterial DNA


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y Efcacy [Ca(OH)2]

availability of hydroxyl ions in solution

dependent on vehicle that is used.


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y Medicament vehicle very imp. role in overalldisinfection

y determines velocity of ionic dissociation,

y enable paste to be solubilized / resorbed at

varying rates.


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y Lower the viscosityhigher ionic dissociation .

y High mol. wt. of common vehicles

minimizes dispersion into the tissue

maintains paste in desired area for longer

duration .


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Three main types of vehicles used:

(1)water soluble substances

water, saline, local anesthesia, ringers solution

(2) viscousvehicles

glycerin, polyethylene glycol, and propyleneglycol (PG)

(3) oil-based vehicles olive oil, silicone oil, camphor, eugenol,

metacresylacetate


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y In 1982,

yAnthony et al studied effect of vehicles on pH ofcalcium hydroxide.

y Concluded that calcium ions diffuse throughapical foramen and change the PH.


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y Chitosan natural polysaccharide widely usedpharmaceutic excipient.

y synthesis -partial deacetylation of chitin,

y derivative of exoskeleton of arthropods.


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y copolymers of glucosamine and N-acetyl glucosamine .

biological actions:

y hypocholesterolemic

y antimicrobial

y wound healing

y mucoadhesivey sustained release


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y products available as powder, paste.

y combined with collagen sponge as a barriermembrane in periodontal therapy

y an oral mucosal delivery agent for chlorhexidineagainst Candida albicans .

y Ballal et al

y chitosan enhanced sustained release of chlorhexidinegluconate against Enterococcus faecalis.


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y Guar gum gum from ground endosperms -cyamopsis tetragonlolbus.

y highmol.wt. hydrocolloidal polysaccharide ofgalactose and mannan units.

y used in cosmetics, food products and pharmaceuticformulations as a binder and thickening agent

y Has a sustained release property (George and Abraham)


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y Chitosan (85% deacetylated) Sigma-AldrichChemicals, Taufkirchen, Germany.

y PG, polyethylene glycol 6000 (PE 6000), and guar gum( Universal Lab. Mumbai, India).


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y Hydrophilic polymers

y PG, PEG 6000, chitosan, and guar gum were used .

y Different concentrations of hydrophilic polymers for desired release of calcium ions


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y Ethical clearance Ethical Committee (IEC 008/2009)of Manipal University, Manipal, Karnataka, India.

y 40 human maxillary anterior teeth ---extracted for

periodontal reasons .


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y Soft-tissue remnants on tooth surface -removed usinga soft brush.

y Teeth examined for fractures, cracks, or any otherdefects using magnifying loupes.

y Teeth stored in solution of 0.05% sodium azide innormal saline at 4 degree C


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y Solution changed daily until sufcient number ofsamples were collected.

y The crowns of all the teeth were removed at the CEJ

using a diamond disc 15 mm.


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y The root canal was enlarged initially up to size 20using K-les , and the pulp tissue was removedusing barbed broach.

y working length of the root canal was determined .

y each tooth was instrumented upto size 45 apically.


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y Coronally the canal was enlarged using G. G .drillsno. 2 to 5.

y After each instrument, the canal was passively

irrigated with 2 mL of 2.5% NaOCl .y The nal irrigation was performed with 2 mL of

17% EDTA solution


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y Finally, the root canal was ushed with 5 mL ofdistilled water .

y The teeth were then divided into four group :

group 1PGgroup 2 PEG 6000

group 3 chitosan

group 4guar gum


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y A vial method was adopted .

y Accurately measured quantities of differentformulations were performed to the root canal using

K-les up to 1 mm short of the working length.y The formulations were further condensed with an

endodontic nger plugger.


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y While lling the root canals, each root was held in amoist gauze to prevent the smearing of theformulations onto the root surface .

y

The orice of the root canal of all the teeth was sealedwith GIC


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y The teeth were then suspended in the glass vials -10mL of distilled water.

y the pH and the calcium ion concentrations weremeasured.

y

Solutions of 3.0 mLwere then withdrawn periodicallyat predetermined time intervals up to 24 hours and at7, 15, and 30 days.


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y The vials were tightly closed with the help ofmolding wax.

y The solutions were analyzed using an ultraviolet

spectrophotometer at 220 nm .


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y The change in pH of all the different formulationswas determined by pH meter

y Each sample was tested three times, and the mean

value for each experimental group was calculated


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y PG showed cumulative drug release of 96.64%

0.56% at the end of 15 daysy PEG 6000, chitosan, and guar gum showed cumulative

drug release of 98.22% 0.25%, 86.88% 0.68%, and96.03% 0.42%, respectively, at the end of 30 days.

y Among all the formulations tested, chitosan showed acumulative drug release of 86.88% 0.68% for aperiod of 30 days


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y The pH of different groups on rst day was found to be7.0.

y After 30 days, pH was found to be 10.3, 10.7, 10.2, and11.2.


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y The imp. of the alkalinizing effects of calciumhydroxide and its capacity to produce OH ions in theperiapical environment has been reported

y Nerwich et al pH changes in root dentin over a 4-week period and considered as a reasonable timeinterval to expect effective therapeutic benets .


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y Placing a formulation of calcium hydroxide with anappropriate vehicle, which can sustain high alkalinepH in the periapical area.

y In the present study, all the formulations showed ahigh alkaline pH (>10) at the end of 1 month.


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y The dissociation of calcium hydroxide in differentvehicles has been shown to be the most efcient way torelease hydroxyl ions .

y

Vehicles can also prolong the duration of the drugeffect signicantly and improve the bioavailability ofthe drug


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y an ultraviolet spectrophotometer was adoptedbecause of its rapid analysis and the cost of the

analysis is less expensive


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y All the vehicles used in this study to prepare thecalcium hydroxide gel were biodegradable.

They offer many advantages

y targeting the drug to the specic sites,y controlled release of the drug,

y protection of either the host or the encapsulated drug.

y the drug release rate can be controlled by the selection

of the mol. wt .of the polymer and its compositions


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y chitosan is the second most abundant organic materialnext to cellulose .

exhibits favorable biological properties such as

y nontoxicity,y biocompatibility,

y biodegradability has attracted much interest inpharmaceutic research as a polymeric drug carrier

y as a novel drug absorption enhancer across nasal andintestinal epithelia


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y The release pattern with chitosan was biphasic inmanner.

y The burst release of calcium ions with chitosan in the

initial stages could bey to the drug present at the surface of the polymer.

y because of the presence of free amino groups


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y Chitosan when used as a vehicle exhibited a controlledrelease of calcium ions .

y All four vehicles maintained a high alkaline pH at the

end of 1 month.y the effect of degradable products on the penetration

of intracanal medicaments, sealers, or adhesive resinsinto the dentinal tubules has to be evaluated.


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In Vitro Sustained Release of Calcium Ions And

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