r e v p o r t e s t o m a t o l m e d d e n t c i r m a x i l o f a c . 2 0 1 3;5 4(1):812

Revista Portuguesa de Estomatologia,Medicina Dentria e Cirurgia Maxilofacial

w ww.elsev ier .p t /spemd

Researc

The eon alg

Joana CBenedita

Faculty of D

a r t i c

Article histor

Received 27

Accepted 19

Available on

Keywords:

Disinfection

Alginate

Sodium hyp

Water

Palavras-cha

Desinfeco

CorresponE-mail a

1646-2890/$

http://dx.doh

ffect of water and sodium hypochlorite disinfectioninate impressions

orreia-Sousa, Ana Margarida Tabaio, Andrea Silva, Tnia Pereira, Sampaio-Maia , Mrio Vasconcelos

ental Medicine, University of Porto, Oporto, Portugal

l e i n f o

y:

July 2012

December 2012

line 27 February 2013

ochlorite

a b s t r a c t

Introduction: The control of cross-infection is an imperative issue when dealing with dental

impression materials in Dentistry and the lack of procedures for its control is currently a real

problem. The aims of the present study consisted in evaluating the effectiveness of water

washing and sodium hypochlorite disinfection in reducing the microbial load of alginate

after mouth contact.

Materials and methods: Thirteen students voluntarily participated in the present study. The

inclusion criteria were age between 21 and 24 years, inexistence of smoking habits and sys-

temic and salivary gland pathologies, DMFT index (decay/missing/lled teeth) 5 and toothbrushing with right hand. For each participant, one impression was taken in alginate from

the mandibular arch. These samples were submitted to water wash and sodium hypochlo-

rite disinfection and to subsequent microbiological analysis. Statistical analysis included

the analysis of variance for multiple comparisons (one-way ANOVA) followed by Students

t-test.

Results: After mouth contact, alginate microbial count increased from 1.59 2.79 to2.68 103 6.19 102 CFU/mm2. It was veried that after water wash the microbial countdecreased to 48.5% while after sodium hypochlorite disinfection microbial count decreased

to 99.99%.

Conclusion: Dental impression materials can act as vectors transmitting a signicant amount

of microorganisms. Sodium hypochlorite disinfection is an efcient disinfection method for

alginate impressions. Tap water rinsing reduces microbial load but does not eliminate the

cross-infection potential of alginate.

2012 Sociedade Portuguesa de Estomatologia e Medicina Dentria. Published by

Elsevier Espaa, S.L. All rights reserved.

A eccia da gua e do hipoclorito de sdio na desinfeco de impressesem alginato

ve:

r e s u m o

Introduco: O controlo da infeco cruzada dos materiais de impresso em Medicina Den-

tria de extrema importncia e a falta de procedimentos para o seu controlo constitui

ding author.

ddresses: bmaia@fmd.up.pt, mbsm@med.up.pt (B. Sampaio-Maia).see front matter 2012 Sociedade Portuguesa de Estomatologia e Medicina Dentria. Published by Elsevier Espaa, S.L. All rights reserved.

i.org/10.1016/j.rpemd.2012.12.003

r e v p o r t e s t o m a t o l m e d d e n t c i r m a x i l o f a c . 2 0 1 3;5 4(1):812 9

Alginato

Hipoclorito de sdio

gua

atualmente um problema real. Os objetivos do presente trabalho consistiram na avaliaco

da eccia da lavagem com gua e da desinfeco com hipoclorito de sdio na reduco da

s o

ntes

21-2

res,

ma im

as fo

robio

zado

ntac

FU/m

uant

ress

um

gu

e infe

uesa

Introduct

The controdealing witimpressionblood, all oganisms. Tassistants, gets of con

Increasidiseases inoutbreak oThis promdures for treason, thfor DiseaseAustralian infection oprofessionaschools anlished reco

In dentihave as msional staba long shematerials uare the mare subdivis an examcommonly manipulatelow-priced.80% of wabition (abswater).11,13

The selematerial ch

er threviosinfe

hy hy

te.1 I Env

to t ag

unpre aals: llowssion

thaes.10,

sidercarga microbiana do alginato ap

Material e mtodos: Treze estuda

de incluso foram a idade entre

sistmicas e das glndulas saliva

escovagem com a mo direita. U

de cada participante. As amostr

e, posteriormente, anlise mic

e o teste t de student foram utili

Resultados: O alginato aps o co

biana de 2,68 103 6,19 102 Ccarga microbiana em 48,5%, enq

a carga microbiana em 99,99%.

Concluso: Os materiais de imp

ismos. O hipoclorito de sdio

alginato. Apesar da lavagem com

biana, no elimina o potencial d

2012 Sociedade Portug

ion

l of cross-infection is an imperative issue whenh dental impression materials in Dentistry. Dentals are inevitably in contact with saliva, plaque, andf which containing potential pathogenic microor-herefore, dental care providers as well as dentalstaff and laboratory technicians are possible tar-tamination.13

ng concern over the transmission of infectious dental ofce occurred in the eighties with thef Acquired Immunodeciency Syndrome (AIDS).4

pted the adoption of preventive routine proce-he disinfection of dental impressions. For thate American Dental Association (ADA), Centers

Control and Prevention (CDC) as well as the

not altlines pthe disodiumSodiumalginaby thesideredefcienhas an

Thematerision aimprestortionsurfacis conDental Association published guidelines for dis-f dental impressions.57 However, the majority ofls who work in hospitals, private clinics, dentald prosthetic laboratories do not follow the pub-mmendations.2,3,810

stry there are several impression materials thatain features: accuracy, elastic recovery, dimen-ility, ow, exibility, workability, hydrophilicity,lf-life, patient comfort and economics.11 Of allsed for impressions, hydrocolloids and elastomersost important in this eld. The hydrocolloidsided in reversible and irreversible. Alginateple of irreversible hydrocolloid and is the mostused material in Dentistry since it is easy to, does not imply specialized equipment and is11,12 As irreversible hydrocolloids are composed ofter they are subject to the phenomena of imbi-orption of water) and syneresis (evaporation of

ction of a disinfectant depends on the impressionosen, given that it should be efcient and should

be immersfew secondimpression

Before dning waterand saliva.5

Given thwas to evahypochloritpurpose wenate withomicroorganimpressionwater pre-wsodium hyp

Materials

Thirteen stof Bachelorcontacto com a cavidade oral.

participaram voluntariamente no estudo. Os critrios

4 anos, ausncia de hbitos tabgicos e de patologias

ndice CPO (dentes cariados, perdidos e obturados) 5 epresso em alginato da arcada mandibular foi obtida

ram submetidas aos mtodos de lavagem/desinfeco

lgica. Os testes ANOVA para comparaces mltiplas

s como ferramentas para a anlise estatstica.

to com a cavidade oral apresentou uma carga micro-

m2. A simples passagem por gua corrente diminui a

o que a desinfeco com hipoclorito de sdio diminui

o podem ser veculos de transmisso de microrgan-

mtodo de desinfeco ecaz para as impresses em

a corrente reduzir signicativamente a carga micro-

co cruzada das impresses em alginato.

de Estomatologia e Medicina Dentria. Publicado por

Elsevier Espaa, S.L. Todos os direitos reservados.

e materials properties.14,15 According to the Guide-usly mentioned, the products recommended forction of impression materials are chlorhexidine,pochlorite, glutaraldehyde and iodine agents.57

pochlorite is the elected disinfecting solution forn addition, sodium hypochlorite is recommendedironmental Protection Agency (EPA) and is con-be a good surface disinfectant, non-irritating andainst wide-spectrum microorganisms; however, itleasant odor and a relevant chemical instability.16

re two disinfection techniques for impressionimmersion and spraying. Disinfection by immer-

the solution to contact with all surfaces of the.10,17,18 Spraying has a lower probability of dis-n the other technique, but it may not reach all19 Yet, the antimicrobial activity of both techniquesed similar.1921 Alginate impressions should not

ed in the disinfectant solution for more than as because it could compromise the quality of the

given its propensity for absorbing water.2,10,21,22

isinfection, a pre-wash of the material with run- is also recommended to remove all debris, blood,7

e above stated facts, the goal of the present studyluate the efciency of water wash and sodiume disinfection of alginate impression. With that

aimed to: (1) evaluate the microbial load of algi-ut mouth contact; (2) evaluate the number ofisms transferred to the alginate after the dental; (3) evaluate the reduction of microbial load afterash and (4) evaluate the disinfecting efciency ofochlorite.

and methods

udents, 6 men and 7 women from the 4th year plus Master degree of Faculty of Dental Medicine

10 r e v p o r t e s t o m a t o l m e d d e n t c i r m a x i l o f a c . 2 0 1 3;5 4(1):812

of Porto University were invited to voluntarily participate inthe present study. Inclusion criteria included age between 21and 24 yeasmoking hagies as wellled teethical and desubject wethe popula(Orthodontmack clinicthe mandibFaculty of Dobtained fr

The expatmosphernate was seenvironmemixed to awater. An im(Frasaco) inprevious toile, non-peralginate imAfter 2 minThe selecteaseptic conmolars. Thing buccalpull of one to minimizteeth (n = 1ing treatmdisinfectionning tap wimmersionSoluco de4.144.51.23the samplemore 10 mi

Followinlogical analwas placedsolution antexed for 5AfterwardsNaCl solutidiately platusing the Mbated aeroband expres(CFU/mm2)of the rst Woelfel.25

The staExcel. The ative frequdescribed 0.05 was cperformed

No wash

Tap water wash

5000

4000

000

000

000

1.00.5

0.0

Alg con

hyo warisowashriso

ay Ans.

ts

ean ats me hawhen adexpnt 2.79 Cer motly tpaireerwad witly biumial c

lly sit aned by

ssion

sults obtained in this study demonstrate that alginate a vehicle for microorganisms transmission and thatction with sodium hypochlorite reduces the microbialresent in this dental material to residual levels. Water

reduces alginate microbial load but does not disin-ciently the dental impression material, so, additionalds should be used.valuate the potential role of alginate in cross-infectiontal setting, some precautions were taken. Alginate wased with newly opened powder and blended with ster-er to avoid contamination of alginate with water-bornrganisms. In addition, in order to understand the con-on of environmental contaminants and alginate-bornrs, tooth brushing with left hand, inexistence ofbit, absence of systemic or salivary gland patholo-l as participants with DMFT (decayed, missing and) index 5 (after a clinical examination). The med-ntal histories as well as oral hygiene habits of eachre obtained by interview in order to characterizetion. For each participant, one alginate impressionic Alginate impression Material Orthoprint, Zher-al, 84702, 2012-02, Rovigo, Italy) was performed atular arch. Informed consent forms, approved byental Medicine ethical committee, were signed andom each participant.erimental protocol was performed in a dental clinice using sterilized materials. After opening, the algi-aled in a sterile bottle and stored in a dry and cleannt. After hand disinfection, the alginate was hand-

homogenous consistency for 30 s using sterilepression was made using articial sterilized teeth

order to evaluate the microbial load of alginate mouth contact. Simultaneously, a universal, ster-forated impression tray was loaded with the samepression material and transferred to the mouth.

the impression was separated from the mouth.d impression area to study was dissected underditions and consisted in the rst and second rightese selected teeth were divided in 3 parts follow-lingual direction. Each sample was constituted by athird of each tooth (rst and second molar) in ordere the difference of microbial colonization between3). Each pull was submitted to one of the follow-ents: (1) sample was left untreated, without any

methodology; (2) sample was washed with run-ater during 15 s and (3) sample was disinfected by

in 0.5% of sodium hypochlorite (Hipoclorito 0.5% Dakin, AGA lcool e Genricos alimentares S.A.,.15, Lisboa, Portugal) during 15 s followed by placing

in a gaze embedded with the same disinfectant forn.5,23

g the exposure to treatment regimes, the microbio-ysis was performed. For that purpose, each sample

in sterile tubes containing 3 mL of 0.9% NaCl steriled sterile glass beads. The tubes were then vor-

+ 5 + 5 s to release the adhered microorganisms., the suspensions were serially diluted with 0.9%on until 102. The resulting samples were imme-ed in triplicate in Brain Heart Infusion (BHI) agariles and Misra method.24 The plates were incu-ically at 37 C for 48 h. The colonies were countedsed as colony-forming units per square millimeter. The tooth area was determined by mean valuesand second right molars, described by Scheid and

tistical analysis was performed using Microsoftcategorical variables were described through rel-encies (%) whereas continuous variables were

using mean standard deviation (SD). A level ofonsidered signicant (p). Statistical analysis wasby Students t-test for unpaired comparisons and

3

2

1CFU/

mm

2

Fig. 1 mouthsodiumfrom ncompawater compa

one-wpariso

Resul

The mticipanhygienbrush both. I

As infecta1.59

Aftnicanfor un

Aftwashenican

Sodmicrobtisticacontacfollow

Discu

The reacts asdisinfeload prinsingfect efmetho

To ein denpreparile watmicrootributiSodium hypochlorite disinfection

#*

*

inate microorganisms quantication aftertact, with no wash, after tap water wash or afterpochlorite disinfection. * Signicantly differentshed alginate (Students t-test for paired

ns, p < 0.01) and # signicantly different from taped alginate (Students t-test for paired

ns, p < 0.01).

NOVA followed by Students t-test for paired com-

ge of the participants was 21.9 0.3 years. The par-ean DMFT index was 2.46 0.63. In respect to oralbits, 84.6% of the participants used manual tooth-reas 7.7% used electric toothbrush and 7.7% useddition, 46.1% used mouthwash.ected, alginate without mouth, water or dis-contact, presented very low microbial load,FU/mm2.uth contact, alginate microbial load increased sig-

o 2.68 103 2.23 103 CFU/mm2 (Students t-testd comparisons, p = 0.0019).rds, the alginate used in dental impression wasth tap water and its microbial load decreased sig-y 48.5% (Fig. 1).

hypochlorite disinfection of alginate decreasedount by 99.99% (Fig. 1). This reduction was sta-gnicant when compared to alginate with mouthd when compared to alginate with mouth contact

tap water wash (ANOVA, p = 0.00003).

r e v p o r t e s t o m a t o l m e d d e n t c i r m a x i l o f a c . 2 0 1 3;5 4(1):812 11

microorganisms on total microbial load, samples of alginatewithout mouth contact were evaluated. Our results showedthat extra-mmicrobial lthe impresand secondhanded anright side omolar was being expoanatomic feples were ea larger samtooth.

Two diffalginate aftand sodiumods emplothe most eby 99.99%. samples wimpressionrite treatmwith somethe impressimple rinsamount of This resultcolleagues1

between 40tal medicinwater.27 Threduces sigin the imprremain. So,cross-infec

The oralisms, inclunumber of evaluated icosts assocwas the cubic mesophwell as protnot considedanger in iequipmentprevalencesible preseusing the ccol. Howevof growth tion for thyoung popthat the stthe microbcontact, isganism loacross-infecing charact

would be the qualitative evaluation of the isolated microor-ganisms to identify and characterize the microorganisms

d in thog

usio

imrgannfecdisinial loater

l di

tion thaulatid witation

entiaed th

patireceied c

to ped thentision

icts

thor

owle

udy sity

e n

dwin othetal m

Wilksiommpreteratubasioross-tudegmanterialction

dentouth contaminants represent only 0.06% of totaload of alginate after mouth contact. In addition,sion area chosen for analysis consisted in the rst

right molars given that all participants were rightd thus presented greater difculty to brush thef the oral cavity.26 In addition, the rst inferior

chosen because it is one of the rst teeth to erupt,sed earlier to the oral environment, and presentsatures that facilitate biolm adhesion.25 The sam-

xtended to the second molar due to the need to gainple and because this is an adjacent and similar

erent methods of reducing the microbial load ofer mouth contact were evaluated: tap water wash

hypochlorite disinfection. From the two meth-yed, disinfection with sodium hypochlorite wasfcient, reducing alginate adhered microorganismHowever, a partial disintegration of the alginateas observed suggesting that the quality of the

could be compromised after sodium hypochlo-ent. A number of materials are not compatible

disinfectants, which may affect the accuracy ofsion, its texture or dimensional stability.17,20 Theing of the impressions with tap water reduced themicroorganisms in the alginates surface by 48.5%.

is in accordance with the report of Al-Jabrah and9 that showed a reduction of microbial load ranging

and 90%. In many dental settings, including den-e schools, the impressions are only washed withe present work shows that, although this procedurenicantly the amount of microorganisms presentession, many thousands of other microorganisms

an accurate disinfection of dental material to avoidtion is imperative.

microbiota consists of a wide range of microorgan-ding bacteria, yeasts, protozoa and virus. A greatoral bacteria are anaerobes, but only aerobes weren the present study due to the complexity andiated to anaerobic cultures. Brain heart infusionlture medium used for the growing of total aero-ilic bacteria, although some fastidious bacteria asozoa and virus were not able to grow. Viruses werered for this experiment because of the potentialts manipulation and the inexistence of required. Protozoa were also not evaluated due to its low

in our society.28 In a pilot experiment the pos-nce of yeasts, particularly Candida was evaluatedulture medium Sabouraud agar with chloranpheni-er, this approach was abandoned due to absencein the rsts experiments. A plausible explana-is result is the low prevalence of yeasts in theulation or its low adherence to alginate.29 Givenudy was limited to aerobic mesophilic bacteria,ial load observed in alginate samples after mouth

signicantly lower than the real total microor-d emphasizing even more the importance of

tion in dental impressions. In addition, an interest-erization, not performed due to funds limitations,

implietial pa

Concl

Dentalmicroocross-icient microbsion m

Ethica

Protecdeclarethe regtee anAssoci

Condfollowtion ofstudy inform

Right obtainjects mposses

Con

The au

Ackn

This stUniver

r e f e r

1. Glaanddenand

2. Kotof ia li

3. Yuzof catti

4. Berma

5. Infethecross-infections and further understand its poten-enicity.

ns

pression materials can act as a vehicle forisms transmission, playing an important role intion. Sodium hypochlorite disinfection is an ef-fection method. Tap water rinsing can reducead but does not disinfect efciently dental impres-

ials, so, additional methods should be used.

sclosures

of human and animal subjects. The authorst the procedures followed were in accordance withons of the relevant clinical research ethics commit-h those of the Code of Ethics of the World Medical

(Declaration of Helsinki).

lity of data. The authors declare that they havee protocols of their work center on the publica-ent data and that all the patients included in theved sufcient information and gave their writtenonsent to participate in the study.

rivacy and informed consent. The authors havee written informed consent of the patients or sub-oned in the article. The corresponding author is in

of this document.

of interest

s have no conicts of interest to declare.

dgment

was supported by the Faculty of Dental Medicine,of Porto, Portugal.

c e s

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The effect of water and sodium hypochlorite disinfection on alginate impressionsIntroductionMaterials and methodsResultsDiscussionConclusionsEthical disclosuresProtection of human and animal subjectsConfidentiality of dataRight to privacy and informed consent

Conflicts of interestAcknowledgmentReferences