Pevnost adheze ortodontickyâ ch vazebnyâ ch materiaâluê a ortodontickyâchzaâ mkuê Bond strength of orthodontic adhesives and brackets

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Pevnost adheze ortodontickyÂch vazebnyÂch materiaÂluÊ

a ortodontickyÂch zaÂmkuÊ

Bond strength of orthodontic adhesives and brackets

*MUDr. Beata KonkolskaÂ, *Doc. MUDr. MilosÏ SÏpidlen, Ph.D., *Prof. MUDr. Milan KamõÂnek, DrSc., *Mgr. KaterÏina LangovaÂ, Ph.D.

*Ortodonticke oddeÏlenõ Kliniky zubnõÂho leÂkarÏstvõ LF UP Olomouc, CÏeska republika

*Department of Orthodontics, Clinic of Dental Medicine, Medical Faculty of Palacky University, Olomouc **UÂstav leÂkarÏske biofyziky, LF UP Olomouc

**Institute of Medical Biophysics, Medical Faculty of Palacky University, Olomouc

Souhrn

CõÂl:CõÂlem teÂto studie bylo srovnaÂnõÂ pevnosti vazby cÏtyrÏ adhezivnõÂch materiaÂluÊ urcÏenyÂch k lepenõÂ kovovyÂch a

ke-ramickyÂch ortodontickyÂch zaÂmkuÊ na povrch skloviny. Ve vsÏech prÏõÂpadech se jednalo o sveÏtlem tuhnoucõÂ kompo-zitnõÂ pryskyrÏice. Byly to TransbondTM Plus Color Change Adhesive (3M Unitek Monrovia, California), Light

BondTM(Reliance Orthodontic Products Inc., Itasca), ConTec LC (Dentaurum, Germany), KurasperTMF (Kuraray

Medical Inc., Okayama, Japan). DaÂle byl hodnocen Adhesive Remnant Index (ARI) pro urcÏenõÂ mõÂsta narusÏenõÂ ad-heze prÏi odstraneÏnõÂ ortodontickyÂch zaÂmkuÊ.

Metodika:Bylo pouzÏito 240 premolaÂruÊ, ktere byly zality do vaÂlecÏkuÊ s Premacrylem a naÂhodneÏ rozdeÏleny do 8

skupin po 30 vzorcõÂch. Ortodonticke zaÂmky kovove (EliteÒMedium-TwinTM) a keramicke (Signature IIITM) byly

le-peny na povrch extrahovanyÂch premolaÂruÊ. Byla meÏrÏena pevnost vazby tahem ve smyku a stanoven Adhesive Remnant Index pro jednotlive adhezivnõ materiaÂly.

ZaÂveÏr:VyÂsledna meÏrÏenõ pevnostõ vazby se pohybovala od 4,5 MPa do 8,8 MPa. NejvysÏsÏõ nameÏrÏena pevnost

vazby byla u lepidla Light BondTM, nejnizÏsÏõÂ pevnost vazby meÏlo adhezivum ConTec LC. RovneÏzÏ byl zjisÏteÏn

signi-fikantnõ rozdõÂl prÏi stanovenõ Adhesive Remnant Indexu pro jednotlive adhezivnõ materiaÂly a ortodonticke zaÂmky

(Ortodoncie 2011, 20, cÏ. 1, s. 29-38).

Abstract

Aim:The study aimed at comparison of bond strengths of four adhesive materials for attachment of metal and ceramic orthodontic brackets on the enamel surface. All the four were light cured composite resins: TransbondTM

Plus Color Change Adhesive (3M Unitek Monrovia, California), Light BondTM(Reliance Orthodontic Products

Inc., Itasca), ConTec LC (Dentaurum, Germany), KurasperTMF (Kuraray Medical Inc., Okayama, Japan). Further,

Adhesive Remnant Index (ARI) was evaluated to determine the broken place ofadhesion.

Methods:240 premolars were imbedded in rollers with Premacryl and randomly divided into 8 groups with 30

specimens each. Metal orthodontic brackets (EliteÒ Medium-TwinTM) and ceramic orthodontic brackets

(Signa-ture IIITM) were attached onto the surface of extracted premolars. Shear bond strength was measured and

Ad-hesive Remnant Index determined for individual adAd-hesive materials.

Conclusion:The measurements ofshear bond strength oscillated between 4.5 MPa and 8.8 MPa. The best

strength was found for Light BondTM, the lowest value was measured for ConTec LC. Significant differences were

found in Adhesive Remnant Index for individual adhesives and orthodontic brackets(Ortodoncie 2011, 20, No. 1, p. 29-38).

KlõÂcÏova slova:pevnost vazby, adhezivnõ materiaÂl, Adhesive Remnant Index

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Introduction

The technique of bonding introduced by Buonocore in 1955 [1] led to significant changes in esthetic dentis-try and orthodontics. Attachment of brackets to the enamelsurface became the integralpart of orthodon-tic treatment. Though the rate of brackets failure and function during orthodontic treatment varies, one of the factors affecting bond strength is adhesive mate-rial. Brackets may be attached with chemically cured and light cured materials, usually composite resins, glass ionomers, or compomer cements. The advan-tage of light cured material is sufficiently long period of time allowing for precise adjustment and placement of the bracket. The risk of adhesive contamination du-ring polymerization is at the minimum. Another advan-tage is seen in sufficient bond strength acquired diately after polymerization and the possible imme-diate loading of fixed appliance components with orthodontic forces [2, 3].

Optimum adhesive should secure sufficient resi-stance against orthodontic forces and mastication. Af-ter the bracket removal there should remain only mini-mum residue of adhesive on the enamelthat needs to be cleaned. Brackets removal should not result in da-maged enamelsurface [4]. The dada-maged enamelin-clude fissures, hollow (after the prisms are broken), crown fracture is the extreme case (defects of hard dental tissues due to caries or filling). Enamel surface was most frequently damaged when ceramic brackets were applied - the brackets bond strength is enhanced with a silan layer on retention surface. The bond so strong may result in the enamel defect [5]. At the begin-ning of the application of the techniques of orthodontic brackets attachment onto enamelsurface, the main aim was to secure sufficient connection between the etched enameland surface of the bracket retention base. A number of studies dealt with the problem, ma-nufacturers of adhesives and orthodontic brackets strove to enhance the bond strength as much as possi-ble. The bond strength is still the fundamental problem and the topic of a number of investigations. The stu-dies focus not only on bond strength but they deal also with other details such as how fast the material solidify, antibacterialfeatures and anti-caries effects of an ad-hesive, method of brackets removal, amount of adhe-sive residue on the enamelsurface or on bracket after the removal, quick and simple cleaning of adhesive re-sidue from enamel. Artun and Bergland established Adhesive Remnant Index to evaluate adhesive residue on the enamelafter brackets removal[6]. ARI is the ad-ditionalparameter in the evaluation of adhesive mate-rials bond strength. The Index identifies the place of bond failure after the brackets removal.

UÂvod

S naÂstupem techniky leptaÂnõÂ, kterou v roce 1955 za-vedlBounocore [1], dosÏl o k vyÂznamnyÂm zmeÏnaÂm v este-ticke stomatologii, naÂsledneÏ take v ortodoncii. Lepenõ zaÂmkuÊ na povrch skloviny se stalo nedõÂlnou soucÏaÂstõ ortodonticke l eÂcÏby. AcÏkoli mõÂra selhaÂvaÂnõ zaÂmkuÊ a jejich funkce v pruÊbeÏhu ortodonticke l eÂcÏby byÂva ruÊznaÂ, jednõÂm z faktoruÊ ovlivnÏujõÂcõÂch pevnost vazby je zvoleny fixacÏnõ materiaÂl. Lepit zaÂmky muÊzÏeme jak materiaÂly chemicky tuhnoucõÂmi tak sveÏtlem tuhnoucõÂmi. Jedna se veÏtsÏinou o kompozitnõ pryskyrÏice, skloionomernõÂ, eventuaÂl neÏ kompomernõ cementy. PrÏednostõ sveÏtlem tuhnoucõÂho materiaÂlu je dostatecÏneÏ dlouhy manipulacÏnõ cÏas pro prÏesne dosazenõ a umõÂsteÏnõ zaÂmku, minimalizuje se ri-ziko kontaminace lepidla v pruÊbeÏhu vyzraÂvaÂnõÂ. DalsÏõ vyÂ-hodou je dostatecÏna pevnost vazby ihned po polyme-raci a mozÏnost okamzÏiteÂho zatõÂzÏenõ soucÏaÂstõ fixnõÂho aparaÂtu ortodontickyÂmi silami [2, 3].

OptimaÂlnõ adhezivnõ materiaÂlby meÏlzajistit dostatecÏ-nou odolnost vuÊcÏi ortodontickyÂm silaÂm, zÏvyÂkacõÂm tlakuÊm. ZaÂrovenÏ po sejmutõ zaÂmku by meÏlo ulpõÂvat pouze mini-maÂlnõ mnozÏstvõ zbyleÂho adheziva na sklovineÏ k naÂsled-neÂmu nutnaÂsled-neÂmu ocÏisÏteÏnõÂ. SnõÂmaÂnõ zaÂmkuÊ by nemeÏl o veÂst k posÏkozenõ povrchu skloviny [4]. PosÏkozenõ skloviny se muÊzÏe projevit jako prasklina, prohlubenÏ po vylomenõ pri-zmat, extreÂmnõÂm prÏõÂpadem je fraktura korunky zubu (ka-zem, cÏi vyÂplnõ podmõÂneÏne defekty tvrdyÂch zubnõÂch tkaÂnõÂ). K posÏkozenõ povrchu skloviny nejcÏasteÏji vedlo pouzÏitõ ke-ramickyÂch zaÂmkuÊ, ktere majõÂposõÂlenou vazebnou pevnost retencÏnõ plochy silanovou vrstvou. Takto silna vazba ke sklovineÏ mohla zpuÊsobit jejõ posÏkozenõ [5]. ZpocÏaÂtku prÏi technice lepenõ ortodontickyÂch zaÂmkuÊ na sklovinu zubu bylo hlavnõÂm cõÂlem zajisÏteÏnõ dostatecÏneÏ pevneÂho spojenõ mezi naleptanou sklovinou a povrchem retencÏnõ baÂze zaÂmku. RÏada vyÂzkumuÊ se veÏnovala teÂto otaÂzce, vyÂrobci adhezivnõÂch materiaÂluÊ a ortodontickyÂch zaÂmkuÊ se snazÏili sõÂlu vazby maximaÂlneÏ zesõÂlit. Tento zaÂkladnõ probleÂm pev-nosti vazby je staÂle aktuaÂlnõÂm teÂmatem a je rÏadou studiõ zkoumaÂn. Dnes nenõ zkoumana problematika zameÏrÏena pouze na pevnost, ale rovneÏzÏ na rÏadu detailnõÂch jevuÊ, jako naprÏõÂklad rychlost vytvrzovaÂnõ materiaÂlu, antibakteriaÂlnõ charakter a antikarieÂznõ efekt lepidla, technika snõÂmaÂnõ ortodontickyÂch zaÂmkuÊ, mnozÏstvõ zbytkoveÂho lepidla na povrchu skloviny cÏi zaÂmku po sejmutõÂ, rychlost a jednodu-chost ocÏisÏteÏnõ reziduaÂlnõÂho adheziva ze skloviny. Artun a Bergland vytvorÏili Adhesive Remnant Index pro hodno-cenõ zbytkoveÂho adheziva na sklovineÏ po sejmutõ zaÂmkuÊ [6]. Tento index je doplnÏujõÂcõÂm parametrem prÏi hodnocenõ pevnosti vazby adhezivnõÂch materiaÂl uÊ, urcÏuje mõÂsto sel-haÂnõ vazby lepidla po sejmutõ zaÂmkuÊ.

CõÂlem teÂto studie bylo srovnaÂvaÂnõ pevnosti vazby ortodontickyÂch sveÏtlem tuhnoucõÂch kompozitnõÂch ma-teriaÂl uÊ ke sklovineÏ zubu. Byltake hodnocen Adhesive Remnant Index (ARI) pro urcÏenõ mõÂsta narusÏenõ adheze prÏi odstraneÏnõ ortodontickyÂch zaÂmkuÊ.

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This study focused on comparison of bond strength of orthodontic light cured composite materials atta-ched to the enamelsurface. Adhesive Remnant Index (ARI) was evaluated to determine the place of adhesion fracture at the removalof orthodontic brackets

Material and method

Metaland ceramic brackets (EliteÒMedium-TwinTM and Signature IIITM) are attached to the pretreated ena-mel. The brackets were attached to premolars extrac-ted mostly due to orthodontic reasons. Only teeth with macroscopically intact enamel on the buccal surface of the anatomic crown were used.

The study included 240 premolars. Extracted premo-lars were preserved in physiological solution at the tem-perature between 15 and 20°C, the teeth were gradually imbedded in premacryl rollers. The rollers were differen-tiated with the help of 4 colors (yellow, pink, green, tran-sparent); each colour for one adhesive tested. Each spe-cimen was numbered (Fig. 1), than photographed with a stereomicroscope Olympus SZ61 with USB camera uEYE, software QuickPhoto Industrial2.3. A magnifying glass was used, and backlight with a round fluorescent tube, vergency of 8 dioptre.

240 rollers were randomly divided into 4 groups, each of a different colour, and each group consisted of 30 premolars chosen randomly for metal brackets attachment, and 30 premolars for ceramic brackets. In all groups there was the same number of teeth with brackets attached for a longer period of time, and teeth with brackets attached only before shear strength tests. The teeth that loosened from the rollers during the test were excluded from the study. For polymeriza-tion a LED polymerizapolymeriza-tion lamp SDI Radii Plus was used (luminous efficiency 1.500mW/cm2). After the brackets were attached to the enamel, the samples were preserved in distilled water at the temperature 15-20°C untilthe testing started.

Metodika

Na prÏedem prÏipravenou sklovinu jsou lepeny zaÂmky kovove a keramicke (EliteÒMedium-TwinTM a Signa-ture IIITM). PraÂce byla provaÂdeÏna na premolaÂrech extrahovanyÂch prÏevaÂzÏneÏ z ortodontickyÂch duÊvoduÊ. Pro vyÂzkum byly vybraÂny pouze zuby s makroskopicky intaktnõÂm povrchem skloviny na bukaÂlnõ plosÏce anato-micke korunky zubu.

Do studie bylo zarÏazeno celkem 240 premolaÂruÊ. Extrahovane premolaÂry byly uchovaÂvaÂny ve fyziologic-keÂm roztoku prÏi teploteÏ pohybujõÂcõ se v rozmezõ od 15 do 25°C a postupneÏ byly zaleÂvaÂny do premacrylovyÂch vaÂl ecÏkuÊ. VaÂl ecÏky byly prÏi vyÂrobeÏ rozlisÏeny 4 barevnyÂmi odstõÂny (zÏlutyÂ, ruÊzÏovyÂ, zelenyÂ, pruÊhlednyÂ), kazÏda barva prÏirÏazena jednomu zkoumaneÂmu materiaÂlu. KazÏdy vzorek bylcÏõÂselneÏ oznacÏen (Obr. 1), pote vyfotografo-vaÂn prÏõÂstrojem stereomikroskop Olympus SZ61 s USB kamerou uEYE, software QuickPhoto Industrial2.3. Byla pouzÏita lupa s podsvõÂcenõÂm kruhovou zaÂrÏivkou a optickou mohutnostõ 8 dioptriõÂ.

240 vaÂlecÏkuÊ bylo naÂhodneÏ rozdeÏleno tedy do 4 ba-revneÏ rozlisÏenyÂch skupin, kazÏda skupina obsahovala 30 naÂhodneÏ vybranyÂch premolaÂruÊ pro lepenõ kovovyÂch zaÂmkuÊ a 30 pro lepenõ keramickyÂch zaÂmkuÊ. Ve vsÏech skupinaÂch byly rovnomeÏrneÏ zastoupeny zuby s jizÏ delsÏõ dobou nalepenyÂmi zaÂmky, stejneÏ jako zuby, u nichzÏ byl y zaÂmky nalepeny teprve prÏed zkousÏkami pevnosti. Vzorky zubuÊ, ktere se v pruÊbeÏhu trhacõ zkousÏky uvolnily z vaÂl ecÏkuÊ, byly naÂsledneÏ ze studie vyrÏazeny.Pro polyme-raci byla pouzÏita LED polymeracÏnõ lampa SDI Radii Plus (sveÏtelna intenzita 1,500mW/cm2). Po nalepenõ zaÂmkuÊ na sklovinu byly vzorky azÏ do provedenõ testuÊ uchovaÂny v destilovane vodeÏ prÏi teploteÏ od 15 do 25°C.

ZkousÏky pevnosti vazby mohou byÂt provedeny ruÊ-znyÂmi zpuÊsoby, jako zkousÏky pevnosti ve smyku, nebo zkousÏky pevnosti v tahu. Tato studie pouzÏila typ zkousÏky pevnosti ve smyku meÏrÏene tahem. ZkousÏky pevnosti byly provaÂdeÏny na FSI VUT Brno a bylpouzÏit prÏõÂstroj TIRA Test 2300 (Obr. 2), pohybliva cÏaÂst stroje je opatrÏena hlavicõ po-rÏizujõÂcõ zaÂznam, meÏrÏõÂcõ jednotka zaznamena cÏasovy pruÊ-beÏh zkousÏky ve formeÏ grafu. PouzÏita silomeÏrna hlava 1 kN s prÏesnostõ odecÏtu na 0.03 N, rychlost posunu testo-vacõ hlavy byla nastavena na 2,3 mm/min. Po provedenõ tahove zkousÏky a zaznamenaÂnõ hodnot byly labiaÂlnõÂ

Obr. 1:Barevne rozlisÏenõ vzorkuÊ zalityÂch v pryskyrÏicÏnyÂch blocÏcõÂch

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Bond strength may be tested with various methods, e.g. shear bond strength test, or tensile test. In our work we used shear strength test measured with tensile force. Strength testing took place at FSI VUT Brno (Faculty of CivilEngineering) and the device TIRA Test 2300 was used (Fig. 2); the mobile part of the machine has a head with scanner, the measuring unit records the test time flow as a diagram (load gauge 1 kN, the accuracy of rea-ding 0.03 N, advancing speed of the testing head 2.3 mm/min). After tensile testing and recording of values, the labial surfaces of teeth were photographed again. The photographs give evidence about the enamelcon-dition and adhesive residue on a tooth surface. To esta-blish the place of bond failure, the retention surface of the base of the removed bracket was documented. The photographs (a tooth, bracket base) were analyzed to assess Adhesive Remnant Index (ARI). 416 photo-graphs were evaluated. Each photograph was overlaid with a grid separating a bracket base and the place with adhesive remnants after removalof the bracket into 16 boxes (Fig. 3, 4) - 4 lines, 4 columns. In charts the values are filled in according to the presence -1/absence - 0 of the adhesive remnants in the respective box. Compari-son of charts (bracket and surface after bracket removal) shows where the adhesive was damaged. When the chart shows 1 for tooth surface, the adhesive broke off the bracket base; when the charts shows 1 for bracket base, then bond strength failed at the surface tested. When there is 1 for both the tooth and bracket surface, the bond failed in the layer of an adhesive itself, adhesive remnants are both on bracket and tooth. When there is 0 for both tooth and bracket surface, no adhesive was present (i.e. there was an error) - such samples were excluded from the study.

The results of bond strength tests and ARI were sta-tistically evaluated. Analysis of variance (ANOVA) and multiple comparison LSD (Least Significant Difference) tests were used.

Results

Bond strength

The highest values of bond strength were recorded for metalbrackets and for materials TransbondTMPlus Color Change Adhesive, KurasperTMF, Light BondTM. Bond strength was better in case of metalbrackets at-tachment (Table 1, Fig. 5); ceramic brackets showed a bit worse bond strength. The least strength measu-red was found for ConTec LC with attached ceramic brackets. Comparisons of levels of significance pro-plosÏky zubuÊ opeÏt vyfotografovaÂny. SnõÂmky dokumentujõÂ

stav skloviny a zbytku lepidla na povrchu zubu. Pro mozÏ-nost stanovenõ mõÂsta selhaÂnõ vazby byla take fotograficky dokumentovaÂna retencÏnõ plocha baÂze odtrzÏeneÂho zaÂ-mku. Fotografie zubu a baÂze zaÂmku byla analyzovaÂna pro stanovenõ Adhesive Remnant Indexu (ARI). Celkem bylo hodnoceno 416 fotografiõÂ. KazÏda fotografie byla prÏe-kryta mrÏõÂzÏkou deÏlõÂcõÂbaÂzi zaÂmku a mõÂsto zbyleÂho lepidla po odtrzÏenõ zaÂmku na 16 polõÂcÏek (Obr. 3, 4) - 4 rÏady a 4 sloupce. Do tabulek pak byly zaznamenaÂvaÂny hodnoty podle prÏõÂtomnosti lepidla - 1, neprÏõÂtomnost lepidla - 0 v daneÂm polõÂcÏku. PrÏi srovnaÂnõ tabulek (zaÂmek a plocha po odtrzÏenõ zaÂmku) zjistõÂme, kde dochaÂzõ k porusÏenõ ad-heziva. Pokud je jednicÏka v tabulce pro povrch zubu, do-sÏlo k uvolneÏnõ lepidla od baÂze zaÂmku, pokud je jednicÏka v tabulce pro baÂzi zaÂmku, selhala pevnost vazby na testo-vaneÂm povrchu. V mõÂstech kde se vyskytuje jednicÏka v ta-bulce pro povrch zubu i pro povrch zaÂmku, dosÏlo k selhaÂnõ vazby ve vrstveÏ samotneÂho lepidla, vyskytuje se zbytek lepidla i na zaÂmku i na zubu. Pokud by se na povrchu zubu a zaÂmku vyskytla na obou mõÂstech nula, znamena to, zÏe lepidlo nebylo prÏõÂtomno (vyskytla se chyba v postupu) a vzorek je nutno ze studie vyrÏadit.

VyÂsledky pevnosti vazby a ARI indexu byly podro-beny statistickeÂmu hodnocenõÂ, byly pouzÏity testy ana-lyÂza rozptylu ANOVA, a testy mnohocÏetneÂho porov-naÂnõÂ LSD (Least Significant Difference).

VyÂsledky

Pevnost vazby

NejvysÏsÏõ hodnoty pevnosti vazby byly nameÏrÏeny u kovovyÂch zaÂmkuÊ a materiaÂl uÊ TransbondTMPlus Co-lor Change Adhesive, KurasperTM F, Light BondTM. Pevnost vazby byla vysÏsÏõ v prÏõÂpadeÏ lepenõ kovovyÂch zaÂmkuÊ, (Tab. 1, Obr. 5), keramicke zaÂmky prokaÂzaly lehce nizÏsÏõ pevnost vazby. Adhezivnõ materiaÂlConTec LC dosaÂhlnejmensÏõ nameÏrÏene sõÂly v kombinaci s lepe-nyÂmi keramickyÂmi zaÂmky. SrovnaÂnõÂm hladin vyÂznam-nosti bylo zjisÏteÏno, zÏe nenõ statisticky signifikantnõ roz-dõÂlv pevnosti vazby mezi materiaÂly TransbondTMPlus Color Change Adhesive, KurasperTMF, Light BondTM ve spojenõ s kovovyÂm zaÂmkem (Tab. 2).

DaÂle se statisticky nelisÏõ materiaÂly TransbondTM Plus Color Change Adhesive, KurasperTM F, Light BondTMve vazbeÏ na zaÂmek keramicky a kovove zaÂmky lepene adhezivem ConTec LC. MateriaÂlConTec LC spolu s keramickyÂmi zaÂmky vykaÂzalnejnizÏsÏõ nameÏrÏene hodnoty pevnosti vazby a statisticky signifikantneÏ se lisÏõ od vsÏech ostatnõÂch druhuÊ lepidel (Tab. 2).

Obr. 3:MrÏõÂzÏka prolozÏena na sklovineÏ po sejmutõÂ zaÂmkuÊ

Fig. 3:Grid on the enamelsurface after de-bonding

Obr. 4:MrÏõÂzÏka prolozÏena na baÂzi zaÂmku po sejmutõÂ

Fig. 4:Grid on the bracket base after debon-ding

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ved there was no statistically significant difference bet-ween bond strength for materials TransbondTM Plus Color Change Adhesive, KurasperTMF, Light BondTM when they were used with metalbrackets (Table 2).

There was no statistically significant difference bet-ween adhesives TransbondTMPlus Color Change Ad-hesive, KurasperTM F, Light BondTM with ceramic brackets and ConTec LC adhesive with metalbrac-kets. ConTec LC with ceramic brackets showed the lo-west values of bond strength measured, and thus the adhesive is significantly different from the rest adhesi-ves tested (Table 2).

ARI

In metalbrackets with allkinds of adhesives tested the remnants were found in most boxes on tooth sur-VyÂsledky ARI

U kovovyÂch zaÂmkuÊ u vsÏech druhuÊ lepidel zuÊstaly zbytky adheziva ve veÏtsÏineÏ meÏrÏenyÂch polõÂcÏek na povrchu zubuÊ, zvlaÂsÏteÏ vyÂrazneÏjsÏõ je hodnota vyÂskytu zuÊstatku na sklovineÏ u lepidel KurasperTMF, Light BondTM. MateriaÂl y, kteryÂmi byly fixovaÂny keramicke zaÂmky na premolaÂry, vy-kazujõ rovneÏzÏ veÏtsÏõ vyÂskyt zbyleÂho adheziva po sejmutõ na povrchu skloviny, nejvysÏsÏõ procento bylo nameÏrÏeno u ad-heziva TransbondTMPlus Color Change Adhesive. Trans-bondTM Plus Color Change Adhesive a ConTec LC ve

0 2 4 6 8 10 12 14 16 18 20 Transbond stainless s. bracket Transbond ceramic bracket Light Bond stainless s. bracket Light Bond ceramic bracket KurasperF stainless s. bracket KurasperF ceramic bracket ConTec stainless s. bracket ConTec ceramic bracket

shear bond strength (MP

a

)

Mean Max. Min.

Obr. 5:VyÂsledky pevnosti adheze. OznacÏeny minimaÂlnõÂ, maximaÂlnõ a pruÊmeÏrne hodnoty v MPa

Fig. 5:Shear bond strength results. Minimal, maximal and mean va-lues in MPa

Tab. 1:VyÂsledne hodnoty pevnosti vazby

Tab. 1:Shear bond strength results

Tab. 2:Statisticke srovnaÂnõ pevnosti vazby

Tab. 2:Statistic comparison of shear bond strength

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vazbeÏ na kovovy zaÂmek majõ vysÏsÏõ procento vyÂskytu ad-heziva na povrchu skloviny i baÂzi zaÂmku, stejneÏ tak se pro-jevuje i adhezivum Light BondTMa KurasperTMve vazbeÏ na keramicky zaÂmek. V tabulce je uvedeno procentuaÂlnõ zastoupenõ mõÂst, na kteryÂch zuÊstaÂva zuÊstatek lepidla. Tyto procentuaÂlnõ hodnoty jsou pocÏõÂtaÂny pro maximaÂlnõ prÏes-nost ne ze zaokrouhlenyÂch hodnot pro jednotlive povrchy (pokud by naprÏõÂklad byl urcÏen zbytek lepidla tam, kde bude ve veÏtsÏineÏ z 16 polõÂcÏek jednicÏka), ale prÏõÂmo z hodnot soucÏtuÊ zuÊstatku lepidla v jednotlivyÂch polõÂch testovacõ mrÏõÂzÏky. Tabulka zobrazuje, v kolika procentech prÏõÂpaduÊ zuÊstaÂva lepidlo na baÂzi zaÂmku, v kolika na povrchu zubu, nebo kolika procenty je zastoupeno reziduum na povrchu zaÂmku i zubu. V prÏõÂpadeÏ, zÏe je tato procentuaÂlnõ hodnota vysÏsÏõ nezÏ 60%, je cÏõÂslo oznacÏeno cÏerveneÏ (Tab. 3).

StatistickyÂm vyhodnocenõÂm jsme nalezli rozdõÂly ve vyÂskytu zbytkuÊ jednotlivyÂch adheziv na sklovineÏ a ba-zõÂch zaÂmkuÊ (Tab. 4, 5).

Diskuse

Pro porovnaÂnõ vyÂsledkuÊ jsme pouzÏili praÂci Tvardka. Tvardek ve sve praÂci hodnotilpevnost vazby ruÊznyÂch adhezivnõÂch materiaÂl uÊ. Jednalo se o kompozitnõ prysky-rÏice sveÏtlem a chemicky tuhnoucõÂ, skloionomernõ ce-menty sveÏtlem a chemicky tuhnoucõÂ, daÂle byl v jeho stu-dii zarÏazen take materiaÂl Spofacryl. Lepeny byly vzÏdy stejne kovove zaÂmky Omniarch (GAC) se sõÂt'ovanyÂm po-vrchem retencÏnõ plochy baÂze zaÂmku. V jeho studii byly hodnoceny pevnosti vazby materiaÂluÊ nejen ve vazbeÏ na povrch extrahovanyÂch premolaÂruÊ, ale hodnotil rov-neÏzÏ vazebnou sõÂlu adhezivnõÂch materiaÂl uÊ na plastovyÂch, kompozitnõÂch, keramickyÂch povrsÏõÂch [8].

V teÂto praÂci byla sveÏtlem tuhnoucõ kompozitnõ adhe-ziva hodnocena pouze ve vztahu ke sklovineÏ zubuÊ (extra-hovane premolaÂry). Studie Tvardka zjisÏt'uje, zÏe v pevnosti vazby dosaÂhly srovnatelneÏ podobnyÂch vyÂsledkuÊ kompo-zitnõÂchemicky tuhnoucõÂmateriaÂlBrackFix NT a akrylaÂtovaÂ

face; the values are particularly high in case of Kura-sperTMF, Light BondTM. Ceramic brackets also show greater amount of adhesive remnants on the enamel surface (the highest values were found out for Trans-bondTM Plus Color Change Adhesive). TransbondTM Plus Color Change Adhesive and ConTec LC with metal brackets show greater amount of residue both on the enamelsurface and bracket base; the same applies to Light BondTMand KurasperTMused with ceramic brac-kets. The table gives the places with adhesive remnants in per cents. The values were calculated not from roun-ded values for individual surfaces (e.g. in case an adhe-sive remnant would be determined in case where there would be 1 in most boxes), but directly from the values of adhesive remnants sums in individualboxes of the te-sting grid. The table shows per cents of adhesive rem-nants on bracket base, on tooth surface, and on both tooth and bracket surface. In case the value in per cents exceeds 60%, the figure is given in red (Table 3).

The statistical evaluation revealed the differences in remnants of individualadhesives on the enameland bracket bases (Table 4, 5).

Discussion

To compare the results we choose a work by Tvar-dek. In his work, Tvardek evaluated bond strength of different adhesives: composite resins (light cured as well as chemically cured), glass-ionomer cements (both light and chemically cured), and Spofacryl. The same metalbrackets Omniarch (GAC) with mesh brac-ket base were used. Tvardek evaluated bond strength of adhesives attached not only to surface of extracted premolars, but also at plastic, composite, and ceramic surfaces [8].

In our work light cured composite adhesives were evaluated only in terms of their attachment to the ena-melsurface (extracted premolars). Tvardek reports Tab. 3:ProcentuaÂlnõÂ zbytky lepidel (ARI) na povrsÏõÂch

Tab. 3:Per centage of remmants (ARI) on surgaces

VeÏtsÏina zbytkuÊ lepidla oznacÏena modrÏe. Zbytky lepidla prÏesahujõÂcõÂ 60 % jsou znacÏeny cÏerveneÏ. Majority of remmants is blue. Adhesive remmants with the value over 60 % are in red color.

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pryskyrÏice Spofacryl. SveÏtlem tuhnoucõ materiaÂly dosaÂ-hly o neÏco nizÏsÏõÂch hodnot pevnosti vazby, nejnizÏsÏõ hod-noty pevnosti vazby Tvardek nameÏrÏilu skloionomernõÂch cementuÊ. PodobneÏ veÏtsÏina studiõ v dostupne literaturÏe hodnotõ kompozitnõ pryskyrÏice jako pevneÏjsÏõ ve srovnaÂnõ se skloionomernõÂmi cementy, pevnost skloionomernõÂch

that composite chemically cured adhesives BrackFix NT and acrylate resin Spofacryl showed similar results of bond strength. Light cured adhesives had a bit lower values of the bond strength; the lowest values were found for glass ionomer cements. Most works publis-hed report more favourable values of bond strength for Tab. 4:Statisticke srovnaÂnõ ARI na povrchu zubu

Tab. 4:Statistic comparison of ARI on tooth surface

Tab. 5:Statisticke srovnaÂnõ ARI na baÂzi zaÂmku

Tab. 5.:Statistic comparison of adhesives on the bracket base

Statisticky potvrzene rozdõÂly, statistically significant differences: * p<0.05, ** p<0.01, *** p<0.001, **** p<0.0001

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materiaÂluÊ byÂva azÏ o 30 % nizÏsÏõÂ. Haydar doporucÏuje lepenõ keramickyÂch zaÂmkuÊ pomocõ skloionomernõÂch cementuÊ, pro zajisÏteÏnõ bezpecÏneÂho snõÂmaÂnõ aparaÂtu [9]. Owens a Miller nezjistili statisticky signifikantnõ rozdõÂl v pevnosti vazby dvou adhezivnõÂch kompozitnõÂch pryskyrÏic, ale dosÏl i k zaÂveÏru, zÏe se lisÏõ signifikantneÏ od sveÏtlem tuhnoucõÂho skloionomernõÂho cementu. Skloionomer se projevil svou pevnostõ slabsÏõÂo 30 % nezÏli kompozitnõÂpryskyrÏice Trans-bond a Enlight [10]. Adhezivum TransTrans-bond XT dosaÂhlo hodnot pevnosti 7.9±2.1 MPa, cozÏ je obdobna hodnota jako ve studii Tvardka.

V nasÏõ studii jsme nameÏrÏili podobne hodnoty vazebne pevnosti u veÏtsÏiny adhezivnõÂch materiaÂl uÊ. JmenoviteÏ ne-bylnalezen statisticky rozdõÂlv pevnosti vazby sveÏtl em tuhnoucõÂch materiaÂl uÊ TransbondTMPlus Color Change Adhesive, KurasperTMF, Light BondTMve spojenõ s ko-vovyÂm zaÂmkem. Tyto materiaÂly vykazujõ nejvysÏsÏõ zmeÏrÏe-nou pevnost vazby. TransbondTMPlus Color Change Adhesives meÏlpruÊmeÏrnou hodnotu pevnosti 8,4 MPa, KurasperTM F 8,2 MPa, nejveÏtsÏõ pruÊmeÏrnou hodnotu jsme nameÏrÏili u adheziva Light BondTMa lepenyÂch kovo-vyÂch zaÂmkuÊ, pruÊmeÏrna hodnota 8,8 MPa, cozÏ jsou po-dobne vyÂsledky jako hodnoty nameÏrÏene u adheziv sveÏ-tlem tuhnoucõÂch v praÂci Tvardka.

PraÂce Moravcove srovnaÂvala vazebnou pevnost 6 druhuÊ keramickyÂch zaÂmkuÊ [11]. PouzÏityÂm adhezivem bylchemicky tuhnoucõ materiaÂlBrackFix NT, kteryÂm byly lepene zaÂmky: Allure (polykrystalicke keramickeÂ), Elation (plastoveÂ) a Envision (plastove polyuretanove s draÂzÏkou vyztuzÏenou kovem) - vykazovaly optimaÂlnõ pevnost vazby (8,687 MPa; 9,987 MPa; 8,214 MPa), monokrystalicke zaÂmky Crystal Clear s vazebnou silou 3,595 MPa a keramicke polykrystalicke zaÂmky s draÂzÏ-kou vyztuzÏenou slitinami zlata Aspire Gold s vazebnou silou 5,736 MPa. Pouze u zaÂmkuÊ Inspire Ice bylo dosa-zÏeno srovnatelne pevnosti vazby (11,054 MPa) jakou uvaÂdõ pro kovove zaÂmky Tvardek (11,324 MPa) [8]. ZaÂ-mek Inspire Ice je polykrystalicky keramicky zaÂZaÂ-mek, tencÏnõ plocha baÂze zaÂmku ma mechanicky zpuÊsob re-tence zajisÏteÏny pokrytõÂm povrchu retencÏnõÂmi perlami.

V nasÏõ praÂci jsme zmeÏrÏili u vsÏech srovnaÂvanyÂch ad-heziv nizÏsÏõ vazebnou sõÂlu vzÏdy ve vztahu ke keramic-keÂmu zaÂmku, cozÏ mohlzaprÏõÂcÏinit rozdõÂlny tvar retencÏ-nõÂch ploch zaÂmkuÊ. Ve studii byly pouzÏity zaÂmky poly-krystalicke s mechanickou uÂpravou retencÏnõ plochy ve formeÏ zaÂrÏezuÊ - preparace tvaru rybiny. PodobneÏ tento zpuÊsob uÂpravy retencÏnõ plochy polykrystalic-keÂho zaÂmku ve studii Moravcove vykaÂzalnizÏsÏõ vazeb-nou pevnost ve srovnaÂnõÂs ostatnõÂmi keramickyÂmi zaÂm-ky (zaÂmek Aspire Gold s vazebnou silou 5,736 MPa).

RÏada studiõÂudaÂva ruÊzne hodnoty pevnosti vazby jako optimaÂlnõ a adekvaÂtnõ pro klinicke pouzÏitõÂ. Tyto hodnoty by meÏl y spl nÏovat dobrou funkci prÏi zatõÂzÏenõ ortodontic-kyÂmi silami, ale zaÂrovenÏ by nemeÏl y veÂst k posÏkozenõÂ

composite resins than for glass-ionomer cements (strength in glass-ionomer adhesives is lower by as much as 30%). Haydar recommends using glass-io-nomer cements for ceramic brackets - the removalof brackets seems to be safer [9]. Owens and Miller did not find statistically significant difference of bond strength for the two adhesive composite resins. How-ever, they conclude that composite resins are signifi-cantly different in comparison with light cured glass-ionomer cement. Glass-glass-ionomer was by 30% less strong than composite resins Transbond and Enlight [10]. Bond strength values for Transbond XT were 7.9 ±2.1 MPa, which agrees with the results given by Tvar-dek.

In our study the values of bond strength measured for most adhesives were similar. There was no statisti-cally significant difference in bond strength of light cu-red materials TransbondTMPlus Color Change Adhe-sive, KurasperTMF, Light BondTMcombined with metal brackets. The adhesives mentioned showed the hig-hest values of bond strength. The mean value of bond strength for TransbondTMPlus Color Change Adhesive was 8.4 MPa, for KurasperTMF it was 8.2 MPa. The hig-hest mean value was measured for Light BondTMand metal brackets = 8.8 MPa. Our results are similar to those given by Tvardek for light cured adhesives.

Moravcova made the comparison of bond strength in 6 different ceramic brackets [11]. The adhesive used was chemically cured BrackFix NT, ceramic brackets Allure (polycrystalline ceramic), Elation (plastic), Envi-sion (plastic polyurethane with a groove reinforced with metal) - they revealed optimum bond strength (8.687 MPa; 9.987 MPa; 8.214 MPa); monocrystalline brackets CrystalClear with the bond strength of 3.595 MPa; ceramic polycrystalline brackets with a groove reinforced with gold alloys Aspire Gold - the bond strength of 5.736 MPa. Only with Inspire Ice brac-kets the bond strength was comparable (11.054 MPa) to that reported by Tvardek for metalbrackets (11.324 MPa) [8]. Inspire Ice is a polycrystalline ceramic brac-ket; retention surface of the bracket base uses mecha-nical retention secured by the layer of retention pearls. In our work, in all adhesives was found lower value of bond strength with ceramic brackets, which might be due to the different shape of retention surfaces of the brackets. Polycrystalline brackets with mechani-cally modified retention surface were used - grooves in the shape of dovetail. Similarly, the polycrystalline bracket with the same modification of retention sur-face used by Moravcova also showed lower values of bond strength compared to other ceramic brackets (Aspire Gold, the bond strength of 5.736 MPa).

A number of studies give different values of bond strength as optimum and adequate for clinical use.

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struktur skloviny prÏi snõÂmaÂnõÂzaÂmkuÊ [12, 13, 14]. Dle Rey-noldse je optimaÂlnõ a bezpecÏna pevnost vazby v rozmezõ 5-8 MPa. V literaturÏe nachaÂzõÂme mnoho ruÊznyÂch vyÂsled-nyÂch hodnot pevnostõ vazby pro nejruÊzneÏjsÏõ materiaÂl y, stejneÏ tak je mnoho ruÊznyÂch zpuÊsobuÊ testovaÂnõÂpevnosti vazby. PodobneÏ jsou v literaturÏe uvaÂdeÏny hodnoty va-zebne pevnosti, ktere jsou pro snõÂmaÂnõ zaÂmkuÊ oznacÏo-vaÂny za bezpecÏneÂ, ktere by nezpuÊsobovaly posÏkozenõ skloviny prÏi snõÂmaÂnõ zaÂmkuÊ.

Studie Weinbergera a kol. se zameÏrÏila na srovnaÂnõ pevnosti vazby polykrystalickyÂch a monokrystalickyÂch keramickyÂch zaÂmkuÊ lepenyÂch adhezivnõ pryskyrÏicõ che-micky tuhnoucõÂ, sveÏtlem tuhnoucõÂ, a tuhnoucõÂch pomocõ argon laserove polymerace. NejvysÏsÏõ pruÊmeÏrnou vazeb-nou pevnost vykazovaly monokrystalicke zaÂmky prÏi pou-zÏitõ laser argonove polymerace, hodnota pruÊmeÏrne va-zebne pevnosti byla 29,58 MPa, praÂce se zabyÂvala take vznikem prasklin ve sklovineÏ po sejmutõ zaÂmkuÊ, u obou typuÊ zaÂmkuÊ nebylprokaÂzaÂn vznik novyÂch prasklin jen u materiaÂlu chemicky tuhnoucõÂho. Ostatnõ adheziva pro-kaÂzala vznik prasklin u 10 % prÏõÂpaduÊ nalepenyÂch zaÂmkuÊ [15]. Naproti tomu studie Retiefa prokaÂzala vyÂskyt sklo-vinnyÂch fraktur a prasklin uzÏ prÏi hodnotaÂch pevnosti vazby pod 10 MPa a to prÏi hodnoteÏ 9,7 MPa [16]. RuÊzne hodnoty meÏrÏenyÂch pevnostõ vazby ortodontickyÂch fixacÏ-nõÂch materiaÂl uÊ vyskytujõÂcõ se v literaturÏe se lisÏõÂ, je to daÂno ruÊznyÂmi podmõÂnkami pruÊbeÏhu studiõÂ, rozdõÂlnyÂmi zpuÊsoby testovaÂnõ vazebnyÂch sil. V nasÏõ studii materiaÂly Trans-bondTM Plus Color Change Adhesive, KurasperTM F, Light BondTModpovõÂdajõ kriteriõÂm stanovenyÂch Reynold-sem pro optimaÂlnõ bezpecÏnou pevnost vazby, lepidlo ConTec LC se nachaÂzõ mõÂrneÏ pod hranicõ tohoto limitu.

ZaÂveÏr

Ve studii byla hodnocena pevnost vazby cÏtyrÏ sveÏtlem tuhnoucõÂch kompozitnõÂch materiaÂluÊ TransbondTM Plus Color Change Adhesive, KurasperTM F, Light BondTM, ConTec LC. ByltestovaÂn vzaÂjemny rozdõÂlv pevnosti mezi jednotlivyÂmi adhezivy. DaÂle byla porovnaÂvaÂna pevnost vazby adhezivnõÂch materiaÂluÊ prÏi pouzÏitõ kovovyÂch orto-dontickyÂch zaÂmkuÊ EliteÒMedium-TwinTMa keramickyÂch ortodontickyÂch zaÂmkuÊ Signature IIITM.

VyÂsledna meÏrÏenõ pevnostõ vazby se pohybovala od 4,5 MPa do 8,8 MPa. NejvysÏsÏõ nameÏrÏena pevnost vazby byla u adheziva Light BondTM, nejnizÏsÏõ pevnost vazby meÏl o adhezivum ConTec LC. V teÂto studii testovana adheziva ve vazbeÏ na kovove ortodonticke zaÂmky projevila vysÏsÏõ vazebnou pevnost nezÏ ve vazbeÏ na keramicke ortodon-ticke zaÂmky. StanovenõÂm Adhesive Remnant Indexu bylo urcÏeno mõÂsto selhaÂnõ vazby pro jednotliva adheziva. Byly nalezeny statisticky signifikantnõ rozdõÂly v mõÂsteÏ selhaÂnõ vazby jednotlivyÂch materiaÂluÊ.

AutorÏi nemajõ komercÏnõÂ, vlastnicke nebo financÏnõ zaÂjmy na pro-duktech nebo spolecÏnostech popsanyÂch v tomto cÏlaÂnku.

The bonds should provide a good function when loa-ded with orthodontic forces, at the same time they should not result in damage of the enamel structures during the brackets removal[12, 13, 14]. Reynolds sta-ted the optimum and safe bond strength between 5-8 MPa. In literature we can find a number of bond strength values for a variety of adhesives, as well as different kinds of testing for the bond strength. We can also find different values of bond strength that are considered safe during the brackets removal, and do not cause any damage to the enamel.

The study by Weinberger et al. compared bond strengths of polycrystalline and monocrystalline cera-mic brackets attached with adhesive resin checera-mically cured, light cured, and cured by means of argon-laser polymerization. The highest average bond strength was reached with monocrystalline brackets cured by ar-gon-laser polymerization (the mean value of 29.58 MPa). Weinberger dealt also with the occurrence of cracks in the enamelafter the brackets removal- no cracks ap-peared only when chemically cured adhesive was used (with both types of brackets). Other adhesives proved cracks in 10% of the attached brackets [15]. On the ot-her hand, Retief proved the occurrence of fractures and cracks of the enameleven at values of bond strength be-low 10 MPa (at 9.7 MPa) [16]. The values given by indivi-dualstudies vary. This is due to different conditions, dif-ferent ways to test bond strength. In our study the adhe-sives TransbondTM Plus Color Change Adhesive, KurasperTMF, Light BondTMmeet the criteria given by Reynolds for the optimum safe bond strength. ConTec LC adhesive is moderately below this limit.

Conclusion

The study evaluated bond strength for four light cu-red composite adhesives: TransbondTM Plus Color Change Adhesive, KurasperTMF, Light BondTM, Con-Tec LC. The difference in strength between the indivi-dualadhesives was tested. Further the bond strength of the adhesive materials with metal orthodontic brac-kets EliteÒMedium-TwinTM, and ceramic orthodontic brackets Signature IIITMwas compared.

The values measured were between 4.5 MPa and 8.8 MPa. The highest value of bond strength was found for Light BondTMadhesive, the lowest for ConTec LC. The adhesives tested proved better bond strength when used with metalorthodontic brackets than with ceramic ones. Adhesive Remnant Index was establis-hed to determine the place of bond failure for individual adhesives. Statistically significant differences were found for the place of bond failure for individual adhe-sives.

Authors have no commercial, proprietary or financial interest in products or companies mentioned in the article.

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Liretarura/References

1. Buonocore, M. G.: A simple method of increasing the ad-hesion of acrylic filling materials to enamel surfaces. J. Dent Res. 1955, 34, cÏ. 6, s. 849-853.

2. Bishara, S. E., VonWald, L., Olsen, M. E., Laffoon, J. F.: Effect of time on the shear bond strength of glass ionomer and composite orthodontic adhesives. Amer. J. Ortho-dont. dentofacialOrthop. 1999, 116, cÏ. 6, s. 616 - 620. 3. Movahhed, M.Z., Ogaard, B., Syverud, M.: An in vitro

comparison of the shear bond strength of a resin-reinfor-ced glass ionomer cement and a composite adhesive for bonding orthodontic brackets. Eur. J. Orthodont. 2005, 27, cÏ. 5, s. 477 - 483.

4. Trimpeneers, L. M, Verbeeck, R. M., Dermaut, L. R., Moors, M. G.: Comparative shear bond strength of some orthodontic bonding resins to enamel. Eur. J. Orthodont. 1996, 18, cÏ. 1, s. 89-95.

5. Stratmann, U., Schaarschmidt, K., Wegener, H., Ehmer, U.: The extent of enamelsurface fractures. A quantitative comparison of thermally debonded ceramic and mecha-nically debonded metal brackets by energy dispersive micro - and image-analysis. Eur. J. Orthodont. 1996, 18, cÏ. 6, s. 655- 662.

6. Artun J, Bergland S.: Clinical trials with crystal growth conditioning as an alternative to acid-etch enamel pre-treatment. Amer. J. Orthodont. 1984, 85, cÏ. 4, s. 333-340. 7. Newman, GV.: Epoxy adhesives for orthodontics atta-chments: progress report. Amer. J. Orthodont.1965, 51, s. 901-912.

8. Tvardek, J.: Pevnost vazby ortodontickyÂch adhezivnõÂch materiaÂl uÊ a jejich vliv na sklovinu. Doktorska disertacÏnõ praÂce, LF MU, Brno, 2007.

9. Haydar, B., Sarikaya, S., Ceherli, Z.C.: Comparison of shear bond strength of three bonding agents with metal and ceramic brackets. Angle Orthodont., 1999, 69, cÏ. 5, s. 457-462.

10. Owens, S. E., Miller, B. H.: A comparison of shear bond strengths of three visible light cured orthodontic adhesi-ves. Angle Orthodont., 2000, 70, cÏ. 5, s. 352- 356. 11. MoravcovaÂ, S. Pevnost vazby ortodontickyÂch

estetic-kyÂch zaÂmkuÊ k zubnõÂmu povrchu. AtestacÏnõÂ praÂce, LFMU, Brno, 2010.

12. Asgari, S., Sala, A., English, J., Powers, J.: Clinical eva-luation of bond failure with a self-etching primer: a rando-mized controlled trial. J. Orthodont. 2007, 34, cÏ. 4, s. 234-251.

13. Buonocore, M. G.: The use of adhesives in dentistry. Illinois: Charles C Thomas, 1975.

14. Reynolds, I. R.: A review of direct orthodontic bonding, Brit. J. Orthodont. 1975, 2, cÏ. 2, s. 171-178.

15. Mitiko, F., Kitahara-CeõÂa, F., Mucha, J.N.: Assessment of enameldamage after removalof ceramic brackets. Amer. J. Orthodont. dentofacialOrthop. 2008, 134, cÏ. 4, s. 548-555.

16. Retief, D. H.: Failure at the dental adhesive etched ena-melinterface: J. OralRehab. 1974, 1, s. 265-284.

MUDr.Beata KonkolskaÂ

Klinika zubnõÂho leÂkarÏstvõÂ LF UP PalackeÂho 12, 772 00 Olomouc

ROD OSTRAVA

PrÏehled chystanyÂch zahranicÏnõÂch akcõÂ:

18±23. 6. 2011 Congress of the European Orthodontic Society

Istanbul, Turecko

PrÏehled chystanyÂch domaÂcõÂch akcõÂ:

16. 4. 2011 (zmeÏna termõÂnu!) MariaÂn Svorad

Olomouc ¹SpolupraÂce leÂkarÏe a technika Aneb co je dobre veÏdeÏt o praÂci toho druheÂhoª

Odborny kurz pro leÂkarÏe i zubnõ techniky v ortodoncii

30. 4. 2011 Doc. MUDr. Olga JedlicÏkovaÂ, CSc.

Brno ¹LeÂcÏba ve smõÂsÏeneÂm chrupuª

ZaÂsady leÂcÏby dle indikacõÂ snõÂmacõÂmi i fixnõÂmi aparaÂty v I., II a III. Angl. trÏõÂdeÏ

7. 5. 2011 MUDr. Marie SÏtefkovaÂ, CSc.

Olomouc ¹PodõÂl sester a zubnõÂch technikuÊ v ortodonticke leÂcÏbeϪ

Odborny seminaÂrÏ pro personaÂli zubnõ techniky v ortodoncii

* * *

Informace: ROD Ostrava ± BeÏlova Olga, MojmõÂrovcuÊ 799/45, 709 00 Ostrava-Mar. Hory Tel.: 777 727 152, 800 100 793, e-mail: obchod@rod-ostrava.cz

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