research article antibacterial effect and physical...

Research ArticleAntibacterial Effect and Physical-Mechanical Properties ofTemporary Restorative Material Containing Antibacterial Agents

Amanda Mahammad Mushashe1 Carla Castiglia Gonzaga1

Paulo Henrique Tomazinho2 Leonardo Fernandes da Cunha1 Denise Piotto Leonardi1

Janes Francio Pissaia1 and Gisele Maria Correr1

1Graduate Program in Dentistry School of Dentistry Positivo University Rua Professor Pedro Viriato Parigot de Souza5300 Curitiba PR Brazil2Positivo University Rua Professor Pedro Viriato Parigot de Souza 5300 Curitiba PR Brazil

Correspondence should be addressed to Gisele Maria Correr gmcnolascogmailcom

Received 9 October 2015 Revised 13 December 2015 Accepted 14 December 2015

Academic Editor Jiiang H Jeng

Copyright copy 2015 Amanda Mahammad Mushashe et al This is an open access article distributed under the Creative CommonsAttribution License which permits unrestricted use distribution and reproduction in any medium provided the original work isproperly cited

Introduction For the maintenance of the aseptic chain created during the treatment the coronal sealing becomes paramountAim Evaluating the antibacterial effect and the physical-mechanical properties of a temporary restorative material containingdifferent antibacterial agents Material and Methods Two antibacterial agents (triclosan and chloramine T) were manually addedto a temporary restorative material used as base (Coltosol) The antibacterial action of the material was analyzed using theagar diffusion method in pure cultures of Escherichia coli (ATCC BAA-2336) and Staphylococcus aureus (ATCC 11632) andmixed culture of saliva collection The microleakage rate was analyzed using bovine teeth previously restored with the materialsand submitted to thermocycling in a solution of 05 methylene blue for a period of 24 hours The physical and mechanicalproperties of the materials analyzed were setting time water sorption solubility and compression strength Results No marginalleakage was observed for all groups There was no statistical significant difference in antimicrobial activity setting time watersorption solubility and compression strength among thematerialsConclusionThe addition of antibacterial agents on a temporaryrestorative material did not optimize the antibacterial ability of the material and also did not change its physical-mechanicalproperties

1 Introduction

The success of the endodontic therapy is closely related tothe elimination of the microorganisms in the root canalsystem through a correct biomechanical preparation [1ndash3]For the maintenance of the aseptic chain created during thetreatment the coronal sealing becomes paramount avoidingmarginal percolation of oral fluids and microorganisms intothe system [4 5]

Several studies indicate a direct relationship betweenthe quality of coronal sealing and the success of endodon-tic treatment [4 6ndash9] The coronal leakage by restorativematerial (temporary or permanent) may be responsible forcontamination of the canal and the appearance of periapicalcomplications during the transoperative period [4 5 10 11]

A good cervical plug allows no leakage of intracanalmedication to the oral environment ensuring the integrityof its action as intracanal dressing [12] Furthermore one ofthe main functions of temporary cements is the protectionof dentin tubules exposed during removal of the smearlayer which are susceptible to the infiltration of bacteriaand chemicals [13] Thus the temporary restorative materialmust have properties that prevent leakage allow adhesion tosubstrates and show good dimensional stability mechanicalstrength and antimicrobial activity [12]

The addition of antimicrobial agents to the composi-tion of temporary cements allows conducting sanitizationmaintenance even if there is small bacterial infiltration viacoronary access Furthermore an antibacterial coronal sealercould act in congruence with the canal dressings preventing

Hindawi Publishing CorporationInternational Scholarly Research NoticesVolume 2015 Article ID 697197 5 pageshttpdxdoiorg1011552015697197

2 International Scholarly Research Notices

the development of remaining microorganisms present ininaccessible locations [1 9]

Because of its proven effectiveness widely discussed inthe literature chlorhexidine is considered the ldquogold stan-dardrdquo and is often chosen as a positive control to verifythe competence of other antimicrobial solutions [14] Analternative agent in an attempt to avoid the side effects ofchlorhexidine such as reversible loss of taste and staining ofteeth andmucosal areas among others is triclosan It consistsof a phenolic derivate nonionic broad-spectrum antisepticagent which can act as both bactericidal and bacteriostaticIn the first case it interferes with the bacterial metabolismavoiding uptake of essential amino acids In the second caseit acts in cell membrane permeability allowing leaking ofcytoplasm contents Many products have been coupled intriclosan formulation in order to improve its effects such asGantrez and zinc citrate [14 15]

An antiseptic substance little used in dentistry is chlo-ramine T It is an anionic low surface tension agent whichallows interaction with other pharmaceutical formulas Itsmechanism of action is through an oxidation reaction andprotein hydrolysis by changing the bacterial integrity Itsdisadvantage compared to other agents refers to its lowsubstantivity since in the presence of organic matter andmicroorganisms this substance loses half of its effectivenessin the course of 24 hours [6 9 11 16]

Although the antimicrobial capacity is of paramountimportance it is proven in the literature that the temporaryrestorative materials currently available in the market do nothave such a property [9 16 17] Thus the objective of thisstudy was to evaluate the antimicrobial effect of a temporaryrestorative material containing different agents (triclosan orchloramine T) in its composition and the possible inter-ference of these agents on the physical and mechanicalproperties of the material The hypothesis of this study isthat the addition of these agents to the temporary restorativematerial will allow an antibacterial effect without interferingwith the materialrsquos physical and mechanical properties

2 Material and Methods

21 Antibacterial Activity Evaluation The incorporation ofantimicrobial agents was performed following the minimuminhibitory concentration (MIC) of each substance whichwas determined by the microdilution method The selectedmicroorganisms were the same as used in the antibacterialactivity analysis

The antimicrobial agents (01 triclosan or 06 chlo-ramine T) were manually added to a temporary restorativematerial (Coltosol ColteneWhaledent Altstatten Canton ofSt Gallen Switzerland) in a powder form 002 g of triclosanor 012 g of chloramines T was added to each 20 g of ColtosolThus the groups were described as follows GI Coltosolwithout inclusion of agents (negative control) GII Coltosol+ 01 triclosan GIII Coltosol + 06 of chloramine T

The antibacterial activity of the temporary restorativematerial was evaluated in pure cultures of Escherichia coli(ATCC (American Type Culture Collection) BAA-2336) and

Staphylococcus aureus (ATCC 11632) on a McFarland tube1 scale of turbidity corresponding to approximately 3 times108 CFUmL Evaluation was also made against a mixedculture obtained by plating a dilution of 1100 of collectedsaliva The study was performed under aseptic conditionsavoiding any precipitation of contaminants

Specimens (119899 = 6) with 6mm diameter and 3mm thick-ness were obtained The culture medium of choice wasMueller-Hinton prepared according to the manufacturerrsquosinstructions Thus four Petri dishes of 10 cm in diameterwere obtained a plate made for each microorganism pureculture and two Petri dishes for the mixed culture Thusdata were collected in duplicate increasing the fidelity of thecalculation The pit in the culture medium which housed thecements was done with punch Prior to drilling howeverthe bacteria were plated with sterile swabs After insertionand proper identification of the bodies plates were stored inan oven for a period of 48 hours at a temperature of 35∘CAfter this period the inhibition around the test samples wasmeasuredwith a caliper to an accuracy of 005mmDataweretabulated and submitted to analysis of variance (ANOVA)criterion at a significance level of 5

22 Sealing Ability Evaluation The sealing ability of the tem-porary restorative material in different groups was analyzedby a microleakage test Thirty bovine teeth were selectedcleaned and distributed into 3 groups (119899 = 10) A cavity of25mm depth and 5mm in diameter was made in the middlethird of the buccal surface of each tooth using a cylindricaldiamond bur (3131) (KG Sorensen Cotia Sao Paulo Brazil)The cavities were restored with a single increment of thetemporary restorative material of each group and immersedin distilled water for two hours The specimens were thenstored in 100 relative humidity for 48 hours

Then the specimens were thermocycled (500 cyclesbetween 5 and 55∘C) dried and sealed with two layers ofnail varnish leaving a space of about 2mm around therestoration Next the specimens were bathed in paraffinat 60∘C until complete waterproofing The specimens wereimmersed in a solution of methylene blue 05 for 24 hoursand then washed to remove the excess of dye

For microleakage analysis the specimens were cut in twohalves in a sagittal direction (119899 = 20) The dye infiltrationwas visually evaluated and a score was attributed to eachspecimen as follows 0 absence of infiltration 1 infiltrationon less than half of dentin thickness 2 infiltration on halfof dentin thickness 3 infiltration greater than half of dentinthickness The data were submitted to analysis of variance(ANOVA) at a significance level of 5

23 Physical and Mechanical Properties Evaluation The set-ting time solubility and compressive strength were evaluatedfor all groups according to standard 30 ADA (AmericanDental Association) All specimens were handled at a tem-perature of 23 plusmn 1∘C and relative humidity of 50 plusmn 2

24 Determination of Setting Time Two specimens fromeachgroupwere prepared using a rectangular Teflonmold of 2mm

International Scholarly Research Notices 3

thickness times 35mm length times 20mm width with a centralhole of 10mm diameter placed on a glass plate and filledwith temporary restorative material Then a polyester stripand a glass plate were placed on the specimen surface andthe assembly was pressed (hand pressure) to remove theexcess of the material One hundred and twenty seconds afterpreparation of the sample the specimens were placed in anoven at 37∘Cand 100 relative humidityNinety seconds laterthe sampleswere submerged in a container of deionizedwaterand an indenter needle (Gilmore needlewith 400 g andflat tipof 1mm)was vertically placed on the surface of the specimenremaining for 5 seconds The same procedure was repeatedmaking indentations in the surface at intervals of 15 secondsuntil the time of setting has been reached The setting timewas recorded as the period of time which elapses from thestart of mixing to the time when the needle fails to penetratecompletely the 2mm depth of cement

25 Water Sorption and Solubility Disk-shaped specimens(119899 = 5) 6mm in diameter (119889) and 1mm in height (ℎ) wereprepared for each group All specimens were stored in a des-iccator at 37∘Cwith silica gel and were weighed daily to verifymass stabilization (dry mass 119898

1) which was represented by

mass variations lower than 01mg in any 24 h interval Afterthat the specimens were stored in distilled water at 37∘C for 7days to obtain the mass after saturation in water (119898

2)

The specimens were then placed in a desiccator againat 37∘C and reweighed to obtain a constant dry mass (119898

3)

Weighing was performed using an analytical balance with01mg accuracy (Mettler-Toledo Barueri Sao Paulo Brazil)The volume (119881) of each specimen was calculated based onthe following equation119881 = 1205871198772ℎ (119877 is the specimen radius)The water sorption measurements (SA) and solubility (SL)in mgmmminus3 were calculated as follows SA = 119898

2minus 1198983119881

SL = 1198981minus1198983119881 Data were submitted to analysis of variance

(119901 lt 005)

26 Compressive Strength Test Five cylindrical specimens(4mm times 6mm) were prepared for each group by using adimethylpolysiloxane (Speedex Coltene Altstatten Cantonof St Gallen Switzerland) mold The molds were placed on aglass plate and filled with the temporary restorative materialwith a slight excess A polyester strip and a glass coverslipwere placed on the surface of the material and pressed (handpressure) for removing excess material The assembly wastransferred to the oven and maintained at 37∘C and 100humidity for 1 hour After this period the specimens wereflattened using 600 silicon carbide paper removed from themold and stored at 37∘C in deionized water for 24 hoursThen the specimens were placed in deionized water at 23∘Cfor at least 15 minutes before testing

Before the mechanical test the diameter and thickness ofeach specimen were measured with a digital micrometerThespecimens were placed on a universal testing machine (EmicDL 2000 Sao Jose dos Pinhais Parana Brazil) by placing theflat portion of the specimen into contact with the base of thetesting machine so that the compressive force was applied tothe long axis of the specimen The specimens were loaded at

Table 1 Mean (standard deviation) of inhibition zone (mm) forspecimens (119899 = 2) of the different groups

Group E coli S aureus Mixed cultureGI control 24 (0) 265 (plusmn353) 315 (plusmn212)GII triclosan 245 (plusmn070) 275 (plusmn070) 32 (plusmn565)GIII chloramine T 25 (plusmn141) 28 (plusmn141) 33 (0)119901 valuelowast p = 06036 p = 08050 p = 09112lowast119901 values gt 005 indicate no statistical significant difference (ANOVA)

Table 2 Mean of the setting time for different groups (119899 = 2)

Group Setting time (mean)GI control 1810158403710158401015840

GII triclosan 1610158400510158401015840

GIII chloramine T 1710158402110158401015840

a compression speed of 1mmmin The maximum forceapplied when the specimen fracture was recorded and com-pressive strength was calculated in Nmm2 (MPa) accordingto the equation 119862 = 4119865120587(pi)1198892 where 119865 is the fracture loadand 119889 is the diameter Data were subjected to statisticalanalysis (analysis of variance ANOVA at a significance levelof 5)

3 Results

31 Antibacterial Activity Evaluation Means and standarddeviations of inhibition zones of different groups are shownin Table 1 According to analysis of variance there were nostatistical significant differences in measures of inhibitionzones among groups regardless of the type of culture used

32 Sealing Ability Evaluation No leakage was observed inall groups There is only pigmentation on the temporaryrestorative material

33 Determination of Setting Time Table 2 shows the averagesetting time obtained for the different groups It was observedthat GII and GIII groups showed lower setting times whiletheGI group showed the highest with a value of 18minutes 37seconds Although there is distinction of values this was notstatistically significant indicating that all groupswere similar

34 Water Sorption (SA) and Solubility (SL) Since there wasno difference in the masses 119898

1 1198982 and 119898

3for GI (control)

and GIII (chloramine T) it was only possible to calculatethe SA and SL for GII triclosan (SA = 106103 120583gmm3) andsolubility (SL = 106103 gmm3)

35 Compressive Strength Test Table 3 shows the mean andstandard deviation values of compressive strength for thegroups According to analysis of variance there was nostatistically significant difference among groups (119901 = 05220)


Table 3Mean and standard deviation (SD) of compressive strengthvalues for the different groups (119899 = 7)

Groups Mean (MPa) SD ANOVAlowast

GI control 2541 383 AGII triclosan 2868 703 AGIII chloramine T 2437 970 AlowastMeans followed by the same letter in the column indicate no statisticallysignificant difference (ANOVA 119901 lt 005)

4 Discussion

In dental procedures specifically in endodontic treatmentsmaintenance of aseptic chain becomes paramount Suchmaintenance is achieved by means of an effective isolationadequate biomechanical preparation use of irrigation solu-tions and intracanal medications Despite this an efficientcoronary sealing is also essential to avoid any contaminationof the canals Besides some bacteria may be residual afterthe endodontic treatment collaborating for the reacutizationof periapical diseases Therefore it would be relevant to usetemporary restorative materials with properties that preventmarginal leakage and present a satisfactory antibacterialcapacity

In this study there was no significant difference amonggroups regarding their antibacterial activity against purecultures of E coli S aureus and saliva mixed culturealthough all of them showed inhibition halos with relevantmeasures This fact disagrees with the results obtained byKooper et al [17] wherein using the same methodologythey observed that all temporary restorative materials wereineffective regarding their antibacterial capacity

The results of this study could be related to the inher-ent limitations of the performed test that could hide theexpected results of the experiment groups (G2 and G3) It isunderstood that the inclusion of solidmaterial (specimens) inthe culture medium can hinder the diffusion of antibacterialagent included in the materialrsquos composition causing nodistinction in inhibition of the microorganisms compared tothe negative control group (GI) Therefore further studiesare necessary with different methodologies to verify thecorrelation of the resultswith respect to antibacterial capacity

The GI group (negative control) showed a mean of2733mm inhibition halo In a previous study [16] usingthe same methodology the same material showed a 13mminhibition halo Considering that the test conditions of thisstudy were similar to those in [13] it is assumed that thischange onmeasurements should result from the compositionof the material itself

Regarding the sealing ability of the groups none showedmarginal leakage (dye penetration) which denotes an effi-cient sealing ability of this material However it was observedthat GII and GIII groups showed a deep pigmentation ofthe material whereas in GI just a small surface layer of thematerial was stained Thus it appears that the inclusion ofantibacterial agents favors a higher porosity in the materialwithout interfering with the ability of marginal sealingFurther studies are necessary to evaluate the materials

behavior in long term in an attempt to determine whetherthe materialrsquos staining will not become a source of dentininfiltration

For the maintenance of materialrsquos integrity an adequatemechanical resistance should be present This way the mate-rial can withstand the loads generated during masticatorymovements In this study the highest compressive strengthwas found for GII group However there was no statisticalsignificant difference among groups

The other physical-mechanical properties tested (settingtime andwater sorption and solubility) showed no significantchanges among groups concluding that the addition ofantibacterial agents to the materialrsquos composition did notcause significant interference

Based on the results of this study it can be concluded thatthe addition of antibacterial agents on a temporary restorativematerial did not optimize the antibacterial ability of thematerial and also did not change its physical-mechanicalproperties

Conflict of Interests

The authors declare that there is no conflict of interestsregarding the publication of this paper

References

[1] C Estrela R G Ribeiro C R A Estrela J D Pecora and MD Sousa-Neto ldquoAntimicrobial effect of 2 sodiumhypochloriteand 2 chlorhexidine tested by different methodsrdquo BrazilianDental Journal vol 14 no 1 pp 58ndash62 2003

[2] R F L Galzo M L B Britto M E de L Machado and C KNabeshima ldquoEvaluation of the antibacterial activity of differenttemporary restorative materialsrdquo Revista da Associacao Paulistade Cirurgioes Dentistas vol 68 pp 250ndash253 2014

[3] Y Weng L Howard X Guo V J Chong R L Gregory and DXie ldquoA novel antibacterial resin composite for improved dentalrestorativesrdquo Journal ofMaterials ScienceMaterials inMedicinevol 23 no 6 pp 1553ndash1561 2012

[4] I Heling C Gorfil H Slutzky K Kopolovic M Zalkind andI Slutzky-Goldberg ldquoEndodontic failure caused by inadequaterestorative procedures review and treatment recommenda-tionsrdquo Journal of Prosthetic Dentistry vol 87 no 6 pp 674ndash6782002

[5] G M G Hommez C R M Coppens and R J G De MoorldquoPeriapical health related to the quality of coronal restorationsand root fillingsrdquo International Endodontic Journal vol 35 no8 pp 680ndash689 2002

[6] A Cardoso N C Silva J M Silva D R Herrera A ANeves and E J Leal Silva ldquoAssessment of coronal leakage ofa new temporary light-curing filling material in endodonticallytreated teethrdquo Indian Journal of Dental Research vol 25 no 3pp 321ndash324 2014

[7] M B Kayahan O Malkondu C Canpolat F Kaptan GBayirli and E Kazazoglu ldquoPeriapical health related to the typeof coronal restorations and quality of root canal fillings ina Turkish subpopulationrdquo Oral Surgery Oral Medicine OralPathology Oral Radiology and Endodontology vol 105 no 1 ppe58ndashe62 2008


[8] L-L Kirkevang D Oslashrstavik P Horsted-Bindslev and A Wen-zel ldquoPeriapical status and quality of root fillings and coronalrestorations in a Danish populationrdquo International EndodonticJournal vol 33 no 6 pp 509ndash515 2000

[9] L Tronstad K Asbjoslashrnsen L Doslashving I Pedersen and H MEriksen ldquoInfluence of coronal restorations on the periapicalhealth of endodontically treated teethrdquo Dental Traumatologyvol 16 no 5 pp 218ndash221 2000

[10] E Gjorgievska S Apostolska A Dimkov J W Nicholson andA Kaftandzieva ldquoIncorporation of antimicrobial agents can beused to enhance the antibacterial effect of endodontic sealersrdquoDental Materials vol 29 no 3 pp e29ndashe34 2013

[11] J S Kim and D H Shin ldquoInhibitory effect on Streptococcusmutans and mechanical properties of the chitosan containingcomposite resinrdquo Restorative Dentistry amp Endodontics vol 38pp 36ndash42 2013

[12] I Abramovitz N Beyth Y Paz E I Weiss and S MatalonldquoAntibacterial temporary restorative materials incorporatingpolyethyleneimine nanoparticlesrdquo Quintessence Internationalvol 44 no 3 pp 209ndash216 2013

[13] J R Pires C R Junior and A C Pizzolitto ldquoIn vitro antimicro-bial efficiency of a mouthwash containing triclosangantrez andsodium bicarbonaterdquo Brazilian Oral Research vol 21 no 4 pp154ndash159 2007

[14] R P Teles and F R Fonseca Teles ldquoAntimicrobial agents usedin the control of periodontal biofilms effective adjuncts tomechanical plaque controlrdquoBrazilianOral Research vol 23 no1 pp 72ndash77 2009

[15] A Rathke R Staude R Muche and B Haller ldquoAntibacterialactivity of a triclosan-containing resin compositematrix againstthree common oral bacteriardquo Journal of Materials ScienceMaterials in Medicine vol 21 no 11 pp 2971ndash2977 2010

[16] A M Mushashe J C Bohn R Razzoto S Oliveira and P HTomazinho ldquoEvaluation of antimicrobial capacity andmarginalleakage of provisional restorativematerialsrdquo Perspectives in OralSciences vol 1 no 2 pp 31ndash35 2009

[17] P M P Kooper M L M Andrade M V R So E P MOliveira M G P Carvalho and L L Bammann ldquoIn vitroevaluation of the antimicrobial activity of tem free-eugenoltemporary sealants in front of a mixed culturerdquo Jornal Brasileirode EndoPerio vol 3 pp 28ndash32 2002

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Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

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OrthopedicsAdvances in


the development of remaining microorganisms present ininaccessible locations [1 9]

Because of its proven effectiveness widely discussed inthe literature chlorhexidine is considered the ldquogold stan-dardrdquo and is often chosen as a positive control to verifythe competence of other antimicrobial solutions [14] Analternative agent in an attempt to avoid the side effects ofchlorhexidine such as reversible loss of taste and staining ofteeth andmucosal areas among others is triclosan It consistsof a phenolic derivate nonionic broad-spectrum antisepticagent which can act as both bactericidal and bacteriostaticIn the first case it interferes with the bacterial metabolismavoiding uptake of essential amino acids In the second caseit acts in cell membrane permeability allowing leaking ofcytoplasm contents Many products have been coupled intriclosan formulation in order to improve its effects such asGantrez and zinc citrate [14 15]

An antiseptic substance little used in dentistry is chlo-ramine T It is an anionic low surface tension agent whichallows interaction with other pharmaceutical formulas Itsmechanism of action is through an oxidation reaction andprotein hydrolysis by changing the bacterial integrity Itsdisadvantage compared to other agents refers to its lowsubstantivity since in the presence of organic matter andmicroorganisms this substance loses half of its effectivenessin the course of 24 hours [6 9 11 16]

Although the antimicrobial capacity is of paramountimportance it is proven in the literature that the temporaryrestorative materials currently available in the market do nothave such a property [9 16 17] Thus the objective of thisstudy was to evaluate the antimicrobial effect of a temporaryrestorative material containing different agents (triclosan orchloramine T) in its composition and the possible inter-ference of these agents on the physical and mechanicalproperties of the material The hypothesis of this study isthat the addition of these agents to the temporary restorativematerial will allow an antibacterial effect without interferingwith the materialrsquos physical and mechanical properties

2 Material and Methods

21 Antibacterial Activity Evaluation The incorporation ofantimicrobial agents was performed following the minimuminhibitory concentration (MIC) of each substance whichwas determined by the microdilution method The selectedmicroorganisms were the same as used in the antibacterialactivity analysis

The antimicrobial agents (01 triclosan or 06 chlo-ramine T) were manually added to a temporary restorativematerial (Coltosol ColteneWhaledent Altstatten Canton ofSt Gallen Switzerland) in a powder form 002 g of triclosanor 012 g of chloramines T was added to each 20 g of ColtosolThus the groups were described as follows GI Coltosolwithout inclusion of agents (negative control) GII Coltosol+ 01 triclosan GIII Coltosol + 06 of chloramine T

The antibacterial activity of the temporary restorativematerial was evaluated in pure cultures of Escherichia coli(ATCC (American Type Culture Collection) BAA-2336) and

Staphylococcus aureus (ATCC 11632) on a McFarland tube1 scale of turbidity corresponding to approximately 3 times108 CFUmL Evaluation was also made against a mixedculture obtained by plating a dilution of 1100 of collectedsaliva The study was performed under aseptic conditionsavoiding any precipitation of contaminants

Specimens (119899 = 6) with 6mm diameter and 3mm thick-ness were obtained The culture medium of choice wasMueller-Hinton prepared according to the manufacturerrsquosinstructions Thus four Petri dishes of 10 cm in diameterwere obtained a plate made for each microorganism pureculture and two Petri dishes for the mixed culture Thusdata were collected in duplicate increasing the fidelity of thecalculation The pit in the culture medium which housed thecements was done with punch Prior to drilling howeverthe bacteria were plated with sterile swabs After insertionand proper identification of the bodies plates were stored inan oven for a period of 48 hours at a temperature of 35∘CAfter this period the inhibition around the test samples wasmeasuredwith a caliper to an accuracy of 005mmDataweretabulated and submitted to analysis of variance (ANOVA)criterion at a significance level of 5

22 Sealing Ability Evaluation The sealing ability of the tem-porary restorative material in different groups was analyzedby a microleakage test Thirty bovine teeth were selectedcleaned and distributed into 3 groups (119899 = 10) A cavity of25mm depth and 5mm in diameter was made in the middlethird of the buccal surface of each tooth using a cylindricaldiamond bur (3131) (KG Sorensen Cotia Sao Paulo Brazil)The cavities were restored with a single increment of thetemporary restorative material of each group and immersedin distilled water for two hours The specimens were thenstored in 100 relative humidity for 48 hours

Then the specimens were thermocycled (500 cyclesbetween 5 and 55∘C) dried and sealed with two layers ofnail varnish leaving a space of about 2mm around therestoration Next the specimens were bathed in paraffinat 60∘C until complete waterproofing The specimens wereimmersed in a solution of methylene blue 05 for 24 hoursand then washed to remove the excess of dye

For microleakage analysis the specimens were cut in twohalves in a sagittal direction (119899 = 20) The dye infiltrationwas visually evaluated and a score was attributed to eachspecimen as follows 0 absence of infiltration 1 infiltrationon less than half of dentin thickness 2 infiltration on halfof dentin thickness 3 infiltration greater than half of dentinthickness The data were submitted to analysis of variance(ANOVA) at a significance level of 5

23 Physical and Mechanical Properties Evaluation The set-ting time solubility and compressive strength were evaluatedfor all groups according to standard 30 ADA (AmericanDental Association) All specimens were handled at a tem-perature of 23 plusmn 1∘C and relative humidity of 50 plusmn 2

24 Determination of Setting Time Two specimens fromeachgroupwere prepared using a rectangular Teflonmold of 2mm






2)


3)


2minus 1198983119881


(119901 lt 005)







GII triclosan 1610158400510158401015840



3 Results





1 1198982 and 119898

3for GI (control)







4 Discussion












References


























Biomaterials












Journal of
























2)


3)


2minus 1198983119881


(119901 lt 005)







GII triclosan 1610158400510158401015840



3 Results





1 1198982 and 119898

3for GI (control)







4 Discussion












References


























Biomaterials












Journal of























4 Discussion












References


























Biomaterials












Journal of





































Biomaterials












Journal of



















research article antibacterial effect and physical...

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