Clinical Study Clinical Efficiency of Two Sequences of …downloads.hindawi.com/journals/tswj/2015/690280.pdf · 2019-07-31 · Clinical Study Clinical Efficiency of Two Sequences

Clinical StudyClinical Efficiency of Two Sequences of Orthodontic Wires toCorrect Crowding of the Lower Anterior Teeth

Claacuteudia Maria de Castro Serafim1 Juacutelio de Arauacutejo Gurgel1 Carollyne Mota Tiago2

Rudys Rodolfo de Jesus Tavarez1 and Etevaldo Matos Maia Filho1

1Ceuma University Rua Josue Montello No 1 Renascenca II 65075-120 Sao Luıs MA Brazil2FACIT Dental School Rua D 25 Qd 11 Lt 10 Avenida Jose de Brito George Yunes 77818-650 Araguaına TO Brazil

Correspondence should be addressed to Etevaldo Matos Maia Filho emmaiafilhoyahoocombr

Received 31 March 2015 Revised 7 May 2015 Accepted 11 May 2015

Academic Editor Grant McIntyre

Copyright copy 2015 Claudia Maria de Castro Serafim 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

This study compared time to correction of mandibular anterior crowding using two arch wire sequences one with conventionalnickel-titanium (NiTi) arch wires and the other with conventional and NiTi heat-activated arch wires Twenty-two boys and girls(mean age 1668 plusmn 266) with moderate crowding (3ndash6mm) were assigned randomly to one of two groups and followed up for fivemonths (six assessments) when arch wires were changed Time to crowding correction was analyzed statistically using the Kaplan-Meier method Data were collected during the five-month follow-up and time to correction was compared between groups usingthe log rank test At the end of follow-up mandibular crowding was corrected in 100 of the cases in the group treated with thesequence that includedNiTi heat-activated archwires whereas about 30 of those treated withNiTi arch wires were not completelycorrectedThere was a significant difference in time to complete treatment between groups (log rank = 5996 p lt 005) In the grouptreated with the sequence that included heat-activated wires alignment and leveling of mandibular anterior teeth were completedearlier than in the group treated only with conventional NiTi arch wires Clinical trial registration is found at RBR-7g5zng

1 Introduction

Mandibular anterior crowding has been assigned to discrep-ancies in both tooth andmandibular size and the proportionsof tooth size between maxillaries [1] Tooth morphogenesisthe development of dentition and the growth of the craniofa-cial complex are some of the factors that may be implicated inthe origin of crowding which has been studied in the attemptto define objectives and methods for efficient treatments

Nickel-titanium (NiTi) alloys are widely used for align-ment and leveling because of their low stiffness whichgenerates low intensity forces NiTi heat-activated wires havetwo specific characteristics shape memory and superelas-ticity which result from the capacity of molecular changeswhen being under the effect of temperature and deflection[2 3] Superelasticity combined with shape memory whichis inherent to these alloys simplifies and shortens clinicaltreatments as it decreases working time because it generates

low intensity forces even when wire deflections are large[4]

In vitro and in vivo studies have been showing that NiTiwires optimize the tooth movement [5] since this materialwas included in the wire sequence for orthodontic treatment

In vitro studies have clearly demonstrated that thereare differences in the mechanical properties of conventionaland NiTi heat-activated arch wires Superelasticity in thehysteresis curve of NiTi heat-activated arch wires has adeactivation plateau that is typical of martensitic phase trans-formation This plateau promotes constant forces reportedto be favorable to tooth movement as long as they are lowintensity forces [6ndash8] However few clinical studies haveanalyzed the efficacy and the mechanical properties of NiTiheat-activated wires and the advantages of their clinical useremain controversial and inconclusive [9ndash11]

This study evaluated the time to correct mandibularcrowding using two sequences one of conventional NiTi arch

Hindawi Publishing Corporatione Scientific World JournalVolume 2015 Article ID 690280 5 pageshttpdxdoiorg1011552015690280

2 The Scientific World Journal

Table 1 Arch wires (inches) used in each clinical sequence

Schedule Conventional NiTi arch wires NiTi heat-activated arch wiresFirst month 01210158401015840 NiTiSecond month 01610158401015840 NiTi 01810158401015840 NiTi heat-activatedThird month 01810158401015840 NiTi 01610158401015840 times 02210158401015840 NiTi heat-activatedFourth month 01910158401015840 times 02510158401015840 NiTiFifth month 01910158401015840 times 02510158401015840 steel

wires and the other of conventional and NiTi heat-activatedarch wires testing the null hypothesis that there was nosignificantly statistical difference between the two techniques

2 Material and Methods

21 Sample Calculation The sample calculation was carriedout broaching the following characteristics A two-sided logrank test with an overall sample size of 20 subjects (10 inthe control group and 10 in the treatment group) achieves050 power at a 005 significance level to detect a hazardratio of 040 when the proportion surviving in the controlgroup is 050 The study lasts for 6 time periods of whichsubject accrual (entry) occurs in the first time period (PASS11 Kaysville Utah USA) Given the possibility of ldquodropoutsrdquoin the region of 10 a total of 22 patients were selected

This prospective randomized study was conducted fromMarch 2011 to March 2012 Twenty-two boys and girls (meanage 1668 plusmn 266) were included in the study

22 Patient Selection Patients who accepted to participatein this study signed an informed consent term The studywas approved by the Ethics in Research Committee of Cen-tro Universitario do Maranhao (UniCeuma) under number0014310 and registered at httpwwwensaiosclinicosgovbr(RBR-7g5zng)

Clinical examinations and patient history were used toselect patients and gingivitis caries and other diseases weretreated before appliance placement

23 Inclusion Criteria Inclusion criteria were moderatemandibular anterior crowding (3ndash6mm) at baseline accord-ing to the irregularity index described by Little [12] all teethbeing present in the mandibular arch up to second molarsno prescription for extractions in the mandibular arch noneed for treatment with intermaxillary elastics interproximalstripping open NiTi compression springs or active labialbow no diseases that might affect tooth movement and nosignificant tooth size and shape abnormalities

Patients with a history of trauma and resorption thatfor any reason did not visit the clinic for more than amonth whose mandibular appliance broke or who hadundergone previous orthodontic treatment were excludedfrom the sample

24 Randomization Patients that met inclusion criteria andsigned the informed consent term were randomized to two

groups Paper cards describing the technique to be appliedwere used for randomization sequence 1 conventional NiTiarch wires sequence 2 conventional and NiTi heat-activatedarch wires as recommended by Gurgel (2006) [13]The cardswere sealed in envelopes that were opened later at the time ofrandomization After randomization the treatment followeda previously defined schedule shown in Table 1

The sequences proposed are based on previous studies[5 9 10] whose cross section was defined according to typeof arch wire used (NiTi or NiTi heat-activated) Monthlyexchanges of the arch wires were performed because themoderate crowding [12] is appropriate and allowed to thisclinical procedure

25 Study Models Before placement and after each arch wirechange impressions using Jeltrate Plus (Dentsply PetropolisBrazil) were taken and a plaster study model using SpecialMicrograin Type IV Dental Stone (Vigodent BonsucessoBrazil) was obtained Alignment and levelingweremonitoredfor five months The casts were numbered and data wererecorded in a table with date sequence used arch wireused crowding index and patient name and age Crowdingcorrection was evaluated only for mandibular anterior teethregardless of possible posterior crowding At the end ofthe experimental period patients and sequences used wereidentified for those cases in which crowding had not beencorrected Twenty-two patients were evaluated 11 in eachgroup and 132 casts were obtained and measured

26 Fixed Appliance All patients were treated using a Rothfixed appliance 02210158401015840 slot (3M Sao Jose do Rio Petro Brazil)using conventional andNiTi heat-activated and stainless steelarchwires (OrthometricMarılia Brazil) fixedwith grey colorligature elastic (Morelli Sorocaba Brazil)

27 Crowding Index Thecrowding indexwas defined accord-ing to measurements of the plaster model according to theirregularity index defined by Little [12] A digital calipermeasuring to the nearest 001mm (Mitutoyo DigimaticKyoto Japan) was held parallel to the occlusal plane formeasurements The linear movement of anatomic contactswas measured between the following points mesial aspectof left canine and distal aspect of left lateral incisor mesialaspect of left lateral incisor and distal aspect of left centralincisor mesial aspect of left central incisor and mesial aspectof right central incisor distal aspect of right central incisorandmesial aspect of right lateral incisor distal aspect of rightlateral incisor and mesial aspect of right canine The sum of

The Scientific World Journal 3

Table 2 Mean and standard deviation values of Littlersquos index of irregularity during treatment phases

Group Baseline 1st assessment 2nd assessment 3rd assessment 4th assessment 5th assessmentNiTi sequence 437 (plusmn080) 285 (plusmn086) 182 (plusmn083) 098 (plusmn065) 038 (plusmn064) 023 (plusmn054)NiTiheat-activatedsequence

459 (plusmn075) 263 (plusmn066) 135 (plusmn070) 048 (plusmn055) 016 (plusmn036) 0 (plusmn000)

these fivemeasurements was the irregularity index as definedby Little

28 Operator Calibration A single examiner not directlyinvolved in patient treatment and blind to the type oftreatment to which the patient was subjected was trainedand calibrated to make crowding measurements in the castmodels Calibration consisted of crowding measurementsusing five mandibular arch models at three time points at aninterval of one week between them when five measurementswere made for each model at a total of 75 measurementsIntraclass Correction (ICC) was used to calculate intraexam-iner agreement which was significant that is the measuresfollowed the same pattern (ICC = 0971 119901 lt 0001 95 CI0945ndash0986)

29 Statistical Analysis Crowding indices for each monthwere recorded using a Microsoft Excel 2007 for Windowsspreadsheet (Microsoft Corporation Redmond USA) Afterdata were recorded sex age and mean and standard devi-ation values of crowding indices were described for eachperiod under analysis

A Kaplan-Meier survival curve was built to illustratetreatments completed for a long time and mean time totreatment completion was estimated for each group Treat-ments not completed during the study time were censoredCompleted cases that is those that reached a crowding indexequal to zero in five months were included in the analysisTime to treatment completion between groupswas comparedusing the log rank test

SPSS 210 (IBM Armonk NY USA) was used for allstatistical analyses The level of significance was set at 5

3 Results

After a thorough examination 22 patients were included atthe beginning of the study The mean age was 1643 (plusmn242)for the group with the NiTi sequence and 1690 (plusmn214) forthe groupwith theNiTi heat-activated sequenceMean valuesand standard deviations were similar for both genders

Mean and standard deviation values of crowding indexduring treatment are shown in Table 2 Crowding indicesdecreased uniformly Standard deviation values were similarfor the conventional and NiTi heat-activated sequences ateach time point

Table 3 shows that the treatment of mandibular anteriorcrowding was complete in all cases in the group that used theNiTi heat-activated sequence at the end of the study time (5

Table 3 Number () of cases completed

Group Assessment2 3 4 5

NiTi sequence mdash 1 (91) 6 (545) 8 (727)NiTiheat-activatedsequence

1 (91) 5 (455) 9 (818) 11 (100)

months) whereas 30 of those that used the NiTi sequencewere not complete

There was a significant difference in time to achieveresolution between groups (log rank = 5996 119901 lt 005) Thesequence that used heat-activated arch wires led to crowdingresolution at a shorter time than the sequence of NiTi archwires (Figure 1)

4 Discussion

In the present study treatment for anteroinferior crowdingwas conducted using two clinical sequences incorporatingNiTi and NiTi heat-activated wire Patients with differentdegrees of crowding could complicate the baseline standard-ization however only patients with a degree of crowdingbetween 3 and 6 millimeters were recruited and in additionthe patientsrsquo ages were similar the respective means being1643 for Group I and 169 for Group II

Moreover as far as the methodology used in the presentstudy is concerned the patients were randomly dividedinto two groups and treated in accordance with a standardprotocol Care was taken to standardize the highest possiblenumber of independent variables just varying the wiresequence One highly experienced operator was responsiblefor all clinical procedures The examiner responsible formeasuring the degree of crowding in each phase of treatmentwas blind as to the sequence used in the dental crowdingtreatment

The variable of interest in this study was length of timefrom beginning of treatment to full correction of mandibularanterior crowdingTherefore the level of crowding of patientsin both groups had to be standardized and only individualswith moderate crowding (3 to 6mm) were included in thestudy The group treated with conventional NiTi sequenceshad a mean crowding index of 437mm (plusmn080) whereasin the group that included NiTi heat-activated arch wiresthis index was 459mm (plusmn075) There was no significantdifference between the groups (119901 = 051)


10

08

06

04

02

00

0 1 2 3 4 5

Prop

ortio

n of

not

alig

ned

Treatment duration (months)

TreatmentNiTiNiTi + heat + activated

NiTi + censoredNiTi + heat + activated (censored)

Figure 1 Kaplan-Meier survival estimates Proportion of treatmentsnot completed according to arch wire sequence

The null hypothesis was rejected which demonstratedthat the treatment with NiTi heat-activated arch wiresachieved correction significantly more rapidly than thesequence using only conventional NiTi arch wires

Mandibular crowding may be estimated using the irreg-ularity index recommended by Little [12] Previous studiesfound that this index is a reliable measure when comparedwith visual inspection or computer-assisted analysis [14] andthat it may be used to standardize studies that investigatethe initial final and postretention phases of the treatment ofcrowding One of the limitations of this index is the fact thatit is a measure of irregularity and therefore is not sensitiveto tooth rotation and axial inclination [1 15] Moreover itis not a measure of arch length but a guide to quantifymandibular anterior crowding It was chosen for this studybecause it is simple clinically safe and reliable to evaluatedental crowding and because it has already been used in otherstudies [10 11 16]

In themethod to asses efficacy used in this study (survivalanalysis) participants are classified as dropouts when theyleave the study for any reason In this study no participantwas classified as a dropout In addition survival analysis usesinformation about all participants up to the moment whenthey achieve the planned event or are censored which is anideal technique to analyze binary variables such as crowdingcorrection in our study It is appropriate for longitudinalstudies characterized by different lengths of follow-up foreach participant and loss to follow-up For these reasonssurvival analysis was chosen to describe our results and thelog rank test was used to assess significance of the comparisonbetween the two groups

Our results demonstrated that the sequence that includedNiTi heat-activated arch wires significantly improved thecorrection of mandibular anterior crowding when compared

with the one that used only conventional NiTi arch wiresThis result may be explained by the mechanical propertiesof superelasticity at oral temperatures and shape memoryof the NiTi heat-activated wires When heat-activated archwires are used movement forces of alignment and levelingare present during all the time between activations of thefixed appliance Tooth movement is therefore more efficientbecause of the superelasticity plateau of themartensitic phasetransformations [6]

Although laboratory studies have demonstrated the effi-cacy of materials characterized by superelasticity and shapememory [2] there is little clinical evidence in the literaturesupporting the advantages associated with these mechanicalproperties Also in clinical studies it was possible to observethat NiTi wire is more efficient for alignment procedure[5] This in vivo study of crowding correction demonstratedthis efficacy The inclusion of heat-activated arch wires in asequence of conventional orthodontic arch wires improvedmandibular anterior crowding correction in our five-monthstudy

Continuous scientific development has brought innova-tion to NiTi wires which can now be activated at temper-atures close to those found in the oral cavity NiTi wiresthat feature this specificity called heat-activation are highlyflexible and superelastic [6] With the advent of new alloysstiffness of an orthodontic appliance can now be changedwhile the size and the cross-sectional dimensions of the wiresremain the same Therefore a wide combination of differentforce magnitudes may be produced using wires of the samecross section but having a different modulus of elasticity

Further studies should evaluate the effect that the vari-ables under study here have on the clinical efficiency ofplanned sequences as well as on other parameters such aspatient discomfort and incidence of resorption They shouldalso evaluate differentNiTiwire brands because according tosome authors [7 8] the mechanical properties of NiTi wiresvary significantly between manufacturers

5 Conclusions

The sequence that included NiTi heat-activated wiresachieved correction of mandibular anterior crowding morerapidly than the sequence that used only conventional NiTiwires Five months after baseline assessment mandibularanterior crowding was corrected in 100 of the cases whosetreatment included NiTi heat-activated arch wires

Conflict of Interests

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

References

[1] P P Martins M R Freitas K M Freitas et al ldquoApinhamentoantero-superior revisao e analise crıtica da literaturardquo RevistaDental Press de Ortodontia e Ortopedia Facial vol 12 no 2 pp105ndash114 2007


[2] C J Burstone B Qin and J Y Morton ldquoChinese NiTi wiremdashanew orthodontic alloyrdquo American Journal of Orthodontics vol87 no 6 pp 445ndash452 1985

[3] S Kapila and R Sachdeva ldquoMechanical properties and clinicalapplications of orthodontic wiresrdquo The American Journal ofOrthodontics and Dentofacial Orthopedics vol 96 no 2 pp100ndash109 1989

[4] D Segner and D Ibe ldquoProperties of superelastic wires andtheir relevance to orthodontic treatmentrdquo European Journal ofOrthodontics vol 17 no 5 pp 395ndash402 1995

[5] M A Gravina I H V P Brunharo M R Fraga et alldquoClinical evaluation of dental alignment and leveling with threedifferent types of orthodontic wiresrdquo Dental Press Journal ofOrthodontics vol 18 no 6 pp 31ndash37 2013

[6] J A Gurgel A L Ramos and S D Kerr ldquoFios ortodonticosrdquoRevista Dental Press de Ortodontia e Ortopedia Facial vol 6 pp103ndash114 2001

[7] T N Bartzela C Senn and A Wichelhaus ldquoLoad-deflectioncharacteristics of superelastic nickel-titanium wiresrdquoThe AngleOrthodontist vol 77 no 6 pp 991ndash998 2007

[8] H Nakano K Satoh R Norris et al ldquoMechanical propertiesof several nickel-titanium alloy wires in three-point bendingtestsrdquo The American Journal of Orthodontics and DentofacialOrthopedics vol 115 no 4 pp 390ndash395 1999

[9] N A Mandall C Lowe H V Worthington et al ldquoWhichorthodontic archwire sequence A randomized clinical trialrdquoEuropean Journal of Orthodontics vol 28 no 6 pp 561ndash5662006

[10] E Ong C Ho and P Miles ldquoAlignment efficiency and dis-comfort of three orthodontic archwire sequences a randomizedclinical trialrdquo Journal of Orthodontics vol 38 no 1 pp 32ndash392011

[11] N Pandis A Polychronopoulou and T Eliades ldquoAlleviation ofmandibular anterior crowding with copper-nickel-titanium vsnickel-titaniumwires a double-blind randomized control trialrdquoAmerican Journal of Orthodontics and Dentofacial Orthopedicsvol 136 no 2 pp 152ndash153 2009

[12] R M Little ldquoThe Irregularity Index a quantitative score ofmandibular anterior alignmentrdquoAmerican Journal ofOrthodon-tics vol 68 no 5 pp 554ndash563 1975

[13] J A Gurgel ldquoQual a sequencia de fios ortodonticos maisfavoraveis ao tratamento ortodontico pergunte ao um expertrdquoRevista Clınica de Ortodontia Dental Press vol 5 pp 13ndash202006

[14] A M Tran J D Rugh J A Chacon and J P Hatch ldquoReliabilityand validity of a computer-based Little irregularity indexrdquoAmerican Journal of Orthodontics and Dentofacial Orthopedicsvol 123 no 3 pp 349ndash351 2003

[15] J Jenny and N C Cons ldquoComparing and contrasting twoorthodontic indices the index of orthodontic treatment needand the dental aesthetic indexrdquo American Journal of Orthodon-tics and Dentofacial Orthopedics vol 110 no 4 pp 410ndash4161996

[16] NW Cobb K S Kula C Phillips andW R Proffit ldquoEfficiencyof multi-strand steel superelastic Ni-Ti and ion-implanted Ni-Ti archwires for initial alignmentrdquo Clinical Orthodontics andResearch vol 1 no 1 pp 12ndash19 1998

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Table 1 Arch wires (inches) used in each clinical sequence

Schedule Conventional NiTi arch wires NiTi heat-activated arch wiresFirst month 01210158401015840 NiTiSecond month 01610158401015840 NiTi 01810158401015840 NiTi heat-activatedThird month 01810158401015840 NiTi 01610158401015840 times 02210158401015840 NiTi heat-activatedFourth month 01910158401015840 times 02510158401015840 NiTiFifth month 01910158401015840 times 02510158401015840 steel

wires and the other of conventional and NiTi heat-activatedarch wires testing the null hypothesis that there was nosignificantly statistical difference between the two techniques

2 Material and Methods

21 Sample Calculation The sample calculation was carriedout broaching the following characteristics A two-sided logrank test with an overall sample size of 20 subjects (10 inthe control group and 10 in the treatment group) achieves050 power at a 005 significance level to detect a hazardratio of 040 when the proportion surviving in the controlgroup is 050 The study lasts for 6 time periods of whichsubject accrual (entry) occurs in the first time period (PASS11 Kaysville Utah USA) Given the possibility of ldquodropoutsrdquoin the region of 10 a total of 22 patients were selected

This prospective randomized study was conducted fromMarch 2011 to March 2012 Twenty-two boys and girls (meanage 1668 plusmn 266) were included in the study

22 Patient Selection Patients who accepted to participatein this study signed an informed consent term The studywas approved by the Ethics in Research Committee of Cen-tro Universitario do Maranhao (UniCeuma) under number0014310 and registered at httpwwwensaiosclinicosgovbr(RBR-7g5zng)

Clinical examinations and patient history were used toselect patients and gingivitis caries and other diseases weretreated before appliance placement

23 Inclusion Criteria Inclusion criteria were moderatemandibular anterior crowding (3ndash6mm) at baseline accord-ing to the irregularity index described by Little [12] all teethbeing present in the mandibular arch up to second molarsno prescription for extractions in the mandibular arch noneed for treatment with intermaxillary elastics interproximalstripping open NiTi compression springs or active labialbow no diseases that might affect tooth movement and nosignificant tooth size and shape abnormalities

Patients with a history of trauma and resorption thatfor any reason did not visit the clinic for more than amonth whose mandibular appliance broke or who hadundergone previous orthodontic treatment were excludedfrom the sample

24 Randomization Patients that met inclusion criteria andsigned the informed consent term were randomized to two

groups Paper cards describing the technique to be appliedwere used for randomization sequence 1 conventional NiTiarch wires sequence 2 conventional and NiTi heat-activatedarch wires as recommended by Gurgel (2006) [13]The cardswere sealed in envelopes that were opened later at the time ofrandomization After randomization the treatment followeda previously defined schedule shown in Table 1

The sequences proposed are based on previous studies[5 9 10] whose cross section was defined according to typeof arch wire used (NiTi or NiTi heat-activated) Monthlyexchanges of the arch wires were performed because themoderate crowding [12] is appropriate and allowed to thisclinical procedure

25 Study Models Before placement and after each arch wirechange impressions using Jeltrate Plus (Dentsply PetropolisBrazil) were taken and a plaster study model using SpecialMicrograin Type IV Dental Stone (Vigodent BonsucessoBrazil) was obtained Alignment and levelingweremonitoredfor five months The casts were numbered and data wererecorded in a table with date sequence used arch wireused crowding index and patient name and age Crowdingcorrection was evaluated only for mandibular anterior teethregardless of possible posterior crowding At the end ofthe experimental period patients and sequences used wereidentified for those cases in which crowding had not beencorrected Twenty-two patients were evaluated 11 in eachgroup and 132 casts were obtained and measured

26 Fixed Appliance All patients were treated using a Rothfixed appliance 02210158401015840 slot (3M Sao Jose do Rio Petro Brazil)using conventional andNiTi heat-activated and stainless steelarchwires (OrthometricMarılia Brazil) fixedwith grey colorligature elastic (Morelli Sorocaba Brazil)

27 Crowding Index Thecrowding indexwas defined accord-ing to measurements of the plaster model according to theirregularity index defined by Little [12] A digital calipermeasuring to the nearest 001mm (Mitutoyo DigimaticKyoto Japan) was held parallel to the occlusal plane formeasurements The linear movement of anatomic contactswas measured between the following points mesial aspectof left canine and distal aspect of left lateral incisor mesialaspect of left lateral incisor and distal aspect of left centralincisor mesial aspect of left central incisor and mesial aspectof right central incisor distal aspect of right central incisorandmesial aspect of right lateral incisor distal aspect of rightlateral incisor and mesial aspect of right canine The sum of










3 Results







1 (91) 5 (455) 9 (818) 11 (100)



4 Discussion





10

08

06

04

02

00

0 1 2 3 4 5

Prop

ortio

n of

not

alig

ned













5 Conclusions




References

























Biomaterials












Journal of




























3 Results







1 (91) 5 (455) 9 (818) 11 (100)



4 Discussion





10

08

06

04

02

00

0 1 2 3 4 5

Prop

ortio

n of

not

alig

ned













5 Conclusions




References

























Biomaterials












Journal of




















10

08

06

04

02

00

0 1 2 3 4 5

Prop

ortio

n of

not

alig

ned













5 Conclusions




References

























Biomaterials












Journal of










































Biomaterials












Journal of


























Biomaterials












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Documents

Clinical Study Clinical Efficiency of Two Sequences of …downloads.hindawi.com/journals/tswj/2015/690280.pdf · 2019-07-31 · Clinical Study Clinical Efficiency of Two Sequences