RESISTANCE AND RETENTION OF THREE DIFFERENT
FIBER REINFORCED POSTS IN ENDODONTICALLY
TREATED TEETH WITH OVAL -SHAPED CANALS – AN
INVITRO STUDY
A Di ssertat ion su bm itted
in part ial ful film ent of the r equir em ents
for the degr ee of
MASTE R O F DENT AL SURGE RY
BRANCH – IV
CONSE RVATI VE DENTISTRY AND E NDO DONTICS
DE PART MENT O F CONSE RVATI VE DENTISTRY
AND E NDO DO NTI CS
CERTIFI CATE
This is t o certi f y t hat DR.KAUSH AL YA.P, Post Graduat e student (2014 -2017) in the Departm ent of C ons ervative Denti str y and Endodont ics , Adhi paras akt hi Dental C oll ege and Hospit al, Melm aruvathur – 603319, has done t his diss ertat ion titl ed “A
comparative evaluation of fracture resistance and reten tion of
three different fib er reinforced posts in endod onti cal ly treated
teeth with oval -shaped canals” – An invitro study. Under our
direct guidance and supervision i n parti al ful film ent of t he regul ations l aid down b y t he Tami lnadu DR.M.G.R Medi cal Universit y, Chennai – 600032 for M DS., (Branch -IV)
CONSE RVATI VE DENTIST RY AND ENDO DO NTICS degree examinati on.
Dr.S.Thill ainayagam MDS .,
Principal
Guide
Dr.S.Thill ainayagam MDS .,
Professor & Head Co-Guide
Dr.D.S.Din esh MDS .,
I am ext rem el y gr at eful to Dr.S.Thi l lainayagam MDS., Guide, P rofessor and Head, Depart ment of Cons ervative Dentist r y and Endodont ics, Adhi paras akt hi Dental C oll ege and Hospit al, Melm aruvathur. Words cannot express m y grati tude for hi s qui et confidence i n m y abi lit y to do the st ud y, his willingness to help m e to clear t he stum bli ng bl ocks al ong the wa y and his t rem endous pati ence til l the end of t he st ud y.
It i s m y dut y t o express m y thanks to m y C o -Gui de
Dr.D.S.Din esh MDS., Professor, for his expert gui dance and moral
support during the com pl etion of thi s stud y. I cons ider m ys elf privileged, t o have studi ed, worked and complet ed m y dis sertation under them i n t he departm ent.
M y si ncere thanks to Dr.S.Thill ain ayagam MDS. , our
bel oved P rincipal, Adhi paras akt hi Dental College and Hospit al, Melm aruvathur for provi ding me wit h the opportunit y t o util ize the facili ties of t he coll ege.
I am extremel y grateful to Mr. Mohan Ku mar, Head, Mat eri al Tes ting Lab, C IP ET, Guind y, for grant ing m e permissi on to conduct the stud y i n hi s departm ent and hel ping me t o bring out m y s tud y.
I thank Dr.Priyan ka Ravi MDS., Department of Publi c Healt h Denti str y Adhiparas akt hi Dent al College and Hospit al, for hel ping me with t he stati sti cs i n the study.
I wi ll forever rem ai n grat eful t o m y bat ch m at es who al wa ys inspi red m e, m ade m e feel at home and m ade t he three years of post graduati on a mem orable and unforgett abl e j ourne y.
I t ake this opport unit y t o thank all m y pos tgraduate
coll eagues, juni ors and friends for thei r help and good wis hes . I
thank the supporti ng staff and nu rs es of the Departm ent of Cons ervative Dentis tr y and Endodonti cs, Adhi paras akt hi Dental College and Hospit al for hel ping m e duri ng the cours e of m y diss ert ati on.
encouragem ent throughout m y ca reer.
I am grat eful to the “ALMIGHTY” who has bl es sed m e with such wonderful people and has gi ven me the opport unit y to seek knowledge.
I dedi cat e this dis sertation to m y fam il y members who alwa ys wanted t o s ee m e where I am toda y.
Dr.Kaush alya.P
TITLE OF THE DISSERTATION
“A comparative evaluation of
fracture resistance and retention of
three different fiber reinforced posts
in endodontically treated teeth with
oval-shaped canals" – An invitro
study.
PLACE OF THE STUDY Adhiparasakthi Dental College and Hospital, Melmaruvathur – 603319 DURATION OF THE COURSE 3 years
NAME OF THE GUIDE Dr.S.Thillainayagam MDS., NAME OF CO-GUIDE Dr.D.S.Dinesh MDS.,
I hereb y decl are that no part of the diss ert ati on will be utilized for gai ning financi al assist ance or an y promoti on without obt aining pri or permission of the P rincipal , Adhi paras akt hi Dent al College and Hospit al, Melm aruvat hur – 603319. In addit ion, I decl are that no part of thi s work will be publi shed either i n print or in elect ronic m edi a wit hout the gui des who has been activel y invol ved in diss ertation. The author has the ri ght t o res erve for publi sh work s olel y wit h the perm ission of the P ri nci pal , Adhi paras akt hi Dental C oll ege and Hospit al, M elm aruvat hur – 603319.
Co- G ui de Gui d e & H ead of depart m ent Si gnat ure of candi dat e
BACKGRO UND
Restoration of endodonti call y t reated t eeth remains a m ajor chall enge in dentis tr y, especial l y i n cases of s evere coronal dest ructi on. S uch cases requi re post ret ained rest orations. The m ain reas ons hampering the long t erm success of post ret ained restorations are los s of ret enti on and root fract ure. R etention can be improved b y usi ng resin bas ed lut ing cement s. Root fractures can be minimized b y usi ng fiber posts. Kerst en et al., 1986 reported that shape of the root canal pl a ys an im port ant role in s uccess ful treatm ent, apart from the effi cienc y of different root canal filling techni ques es peci all y in oval shaped canals. Onl y few studies have dem onst rated the fract ure resi stance and retention of different prefabri cated post s yst ems i n oval shaped roo t canals and det ermined the respective failure modes.
AI M
To compare and eval uat e the fract ure resi stance and ret enti on of t hree different fi ber rei nforced posts in endodonti call y t reat ed teeth with oval -s haped canals.
MATE RI ALS AND METHO DS
divided in to 3 groups (n=20) according to the fi ber pos ts used. Group1 (Eversti ck Post), Group 2 (Rel yX Post ), Group 3 (M acrol ock Oval Post). Post space preparati on was done and posts were lut ed wi th t he respective dual cure resi n cem ent . Each group was then divi ded into 2 subgroups (a&b) n=10 for fracture resist ance and retention t ests res pecti vel y. For fracture resi stance test core bui ld up was done wit h di rect com posit e and li ght cured. The ret ention t est did not require any core buil d up. Fract ure resist ance and retent ion tests were performed on each group using universal t esti ng machi ne at a cross head speed of 1mm /min. Failure modes were als o evaluat ed.
RESULTS
The result s showed that t he fractur e res istan ce of group 3a (M acrol ock Oval P ost) was si gni fi cantl y hi gher t han the other two groups . Group 1a had l east fracture resistance. More num ber of unfavourabl e fractures were seen in Group 1a. The ret enti on of group 3b (M acrolock Oval Post ) was si gn ificant l y hi gher t han t he other two groups. Group 1b had l east ret ention.
CONCLUS ION
S.NO TITLE PAGE No.
1. INTRODUC TION 1
2. AIM AND OBJ EC TIVES 5
3. REV IEW OF LITER ATURE 6
4. MATER IA LS AND METHODS 31
5. RESULTS 54
6. GRAP HS 61
7. DISC USS ION 66
8. SUMM ARY & C ONC LUS ION 75
9. REFERENCES 78
Figu re No. TITLE
Page
No.
1.
Armamentarium for preparation of samples and
cleaning and shaping 34
2. Armamentarium for obturation 34
3.
Armamentarium for post endodontic restoration 35
3.1- Everstick Post 35
3.2- Everstick Post and Drill 35
3.3- G-CEM Resin Cement 35
3.4- RelyX Post 36
3.5- RelyX Post and Drill 36
3.6- RelyX U-200 Resin Cement 36
3.7- Macro-Lock Oval Post 37
3.8- Macro-Lock Oval Post and Drill 37
3.9- Sealbond Dual Resin Cement 37
4. Armamentarium for Core Buildup 38
5. Armamentarium for Model Preparation 38
7.
Labiolingual and mesiodistal view of the samples for
evaluation of the oval canals 43
8. Tooth samples before and after decoronation 43
9. Obturated specimens 44
10. Specimens after post space preparation 44
11. Matrices for core buildup 45
12. Samples for fracture resistance test 48
13. Samples for retention test 49
14. Universal testing machine 50
15. Fracture resistance test 51
16. Retention test 51
17. Cross sectional view of oval post adaptation 72
Table No. TITLE Page No.
1. Fiber posts with their respective shape and luting cements
42
2. Fracture resistance of three groups in Newton 55
3. Statistics of fracture resistance values 55
4. Failure modes of each group 56
5. Fracture resistance of Group 1a Vs Group 2a 56
6. Fracture resistance of Group 1a Vs Group 3a 56
7. Fracture resistance of Group 2a Vs Group 3a 57
8. Retention of three groups in Newton 58
9. Statistics of Retention values 59
10. Retention of Group 1b Vs Group 2b 59
11. Retention of Group 1b Vs Group 3b 59
Graph No. TITLE Page No.
1. Mean fracture load 61
2. Failure modes of each group 61
3. Fracture resistance of Group 1a Vs Group 2a 62
4. Fracture resistance of Group 2a Vs Group 3a 62
5. Fracture resistance of Group 1a Vs Group 3a 63
6. Mean Retention 64
7. Retention of Group 1b Vs Group 2b 64
8. Retention of Group 2b Vs Group 3b 65
ANOVA : Anal ys is of Vari ance
CFRC : Carbon Fi ber R ei nforced Composite C-factor : Confi gurati on fact or
DC : Dual Cure Fi g : Fi gure
FRC : Fiber Rei nforced C omposite GFR posts : Gl ass Fiber R einforced posts MOD : Mesio -Occlus o-Dis tal
Ni-C r : Ni ckel -Chromi um
RDIZ : Res in Dentin Int er -diffusi on Zone SC : Sel f C ure
TC : Thermoc ycling
UDM A : Uret hane Dimethacr yl at e
INTRODUCTION
The restorat ion of endodonti call y treat ed t eet h i s a criti cal step in successful root canal t reatm ent.1 Reconst ruction of endodonti call y treat ed t eeth is often necess ar y before the fi nal restoration is placed, especi all y when the rem ai ning coronal t ooth st ructure is not adequat e enough to provide ret ention and resist ance for the final restorati on.2 When t he re is a loss of l arge am ount of clini cal crown due t o damage, it is oft en impossi ble to achieve suffi ci ent anchorage of a restorat ion in the rem ai ning dentin. In s uch situations , a root -canal -ret ained restoration is requi red.3 Hence, post s are indi cat ed fo r endodonti call y treat ed teeth that are hi ghl y suscepti bl e to fract ure becaus e of t hei r insuffi ci ent coronal t ooth structure.4
Restorations of the root fil led toot h b y a post to ret ain a crown dat es back more than 200 years, when Fauchard used posts cons t ruct ed from gol d or s ilver.5 Over the next cent ury, the post crowns becam e the most popular m et hod of rest orati on of traumatiz ed toot h.
There has been a si gnifi cant developm ent in post s ys tem s in recent years with respect t o post and core m aterial s, shape, d esi gn, bondi ng s yst em and techniques for rem oval. Foll owing t raum a if l es s than one hal f of the coronal structure is rem aining on a pulpl ess t ooth, i t is advisabl e to pl ace a post and core, thereb y providing adequat e connecti on of the root st ructure to the coronal core.7 The restorati on of the endodont icall y t reated tooth is an import ant aspect of dent al practi ce invol ving a range of treatm ent options of var ying com pl exit y.8
Modern dentist r y ai ms at pres ervi ng pul pal vit alit y and avoi ding the us e of posts considering post appli cation as the l ast t reatm ent option. If, however, endodonti c therap y is cannot be avoided then the conservati on of the rem aining t ooth structures i s most i mportant. Generall y, endodonticall y t reat ed t eet h have al read y undergone rem arkabl e coronal dest ructi on, loss of radi cul ar dentin, reduced l evel of propri oception and an overall reduction in the capabilit y of the tooth to res ist a large amount of i ntra -oral forces. In the pres ent era o f Aestheti c, Cons ervative and Adhesi ve dentis tr y, aest heti c and functi onal restoration of a pulpl es s tooth is a dem andi ng chall enge.
techni que involvi ng resin based luti ng agent s. Root fract ure can be minimized b y usi ng fiber post whi ch have modulus of el asti ci t y simil ar to denti n that allow for a more uni form distri buti on of l oads along root dentin com pared to met al posts .
However, t he res toration of endodont icall y t reated teet h with fiber –rei nforced pos t s yst em has been drawing the att ention of a constantl y growing number of clini ci ans.
The addi tion of fibers t o a pol ym er mat rix can res ult i n a si gni fi cant improvement i n the m echani cal properti es such as strength, fracture toughnes s, stiffness and fati gue res ist ance.5 Adhesi ve com posit es are us ed to buil d up t he core and form a mechanical unit with the tooth. Also, the m echanical behavi our and rel ated m echanism of fail ure of fiber posts have been compared to thos e of m et al lic posts. While met alli c pos ts tend t o produce an irrevers ibl e root fracture on fai lure, the root fract ure in case of a fi ber posts i s us uall y l ocated m ore coronall y and is m ore easi l y re -t reat abl e. In additi on, the fib er posts are more easi l y retri evabl e t han m et alli c or cerami c post s.
Apart from the above m enti oned factors it has been report ed that shape of t he root canal pl a ys an import a nt rol e in s uccess ful t reatm ent. It is a proven concept that close canal adaptati on with m ini mal tooth struct ure rem oval provides a cons ervative and long l asti ng t reatm ent for the rest oration of endodonti call y treat ed teeth.1 0
Cros s-s ectional root canal confi gurati ons are cl as sifi ed as round, oval, long oval, fl attened or irregular. Oval is defi ned as having a maximum di am et er of upt o two times greater than t he minimum diam et er. P ost pl acement in oval shaped canal s l eads to removal of sound t ooth st ructure t o adapt the post to the canal . This in turn can affect the strength of the tooth structure.1 1
INSTITUTIONAL ETHICS COMMITTEE AND REVIEW BOARD
ADHIPARASAKTHI DENTAL COLLEGE AND HOSPITAL
Melmaruvathur, Tamilnadu-603319
MEMBERS
Prof.Dr.A.Momon Singh,MD
Prof.Dr.H.Murali, MDS
Dr.Muthuraj, MSc, MPhil, PhD
Prof.Dr.T.Ramakrishnan, MDS Prof.Dr.T.Vetriselvan, MPharm, PhD Prof.Dr.A.Vasanthakumari, MDS Prof.Dr.N.Venkatesan, MDS Prof.Dr.K.Vijayalakshmi, MDS
Shri.Balaji, BA, BL
Shri.E.P.Elumalai
CHAIR PERSON
Prof.Dr.K.Rajkumar, BSc,MDS, PhD
MEMBER SECRETARY
Dr.S.Meenakshi, PhD
This ethical committee has undergone the research protocol submitted by DR.KAUSHALYA.P, Post Graduate Student, Department of Conservative Dentistry and Endodontics under the title “A COMPARATIVE EVALUATION OF FRACTURE
RESISTANCE AND RETENTION OF THREE DIFFERENT
FIBER REINFORCED POSTS IN ENDODONTICALLY
TREATED TEETH WITH OVAL-SHAPED CANALS” – AN
INVITRO STUDY" Reference No: 2014-MD-BrIV-SAT-09 under
the guidance of DR.S.THILLAINAYAGAM, MDS., for consideration of approval to proceed with the study.
This committee has discussed about the material being involved with the study, the qualification of the investigator, the present norms and recommendation from the Clinical Research scientific body and comes to a conclusion that this research protocol fulfils the specific requirements and the committee authorizes the proposal.
AIM AND OBJECTIVES
AI M
To compare and eval uat e the fracture resi stance and retention of three di fferent fiber reinforced post s in endodonti call y t reated t eeth with oval -shaped canals.
OBJECTI VES
To evaluat e the fracture resist ance of three different fi ber rei nforced pos t in endodonti cal l y t reated teeth with oval canal s.
To evaluat e the retention of three different fiber rei nforced pos t in endodonti call y t reat ed t eeth wit h oval canals.
To correlat e the rel ation of post geom et ry and fracture resist ance of endodonti call y treat ed t eeth wit h oval canals.
REVIEW OF LITERATURE
Standl ee JP et al (1972)1 2 compared the stres s dist ribution of smoot h
sided parall el post s; smoot h sided tapered posts and threaded parall el posts b y photoel ast i c anal ysi s. The y concluded tapered post s exhibit a wedging effect and produce the hi ghest stres ses at the shoul der. Smooth -si ded paral lel pos ts generate the hi ghest apical st ress es.
Lovdahl PE et al (1977)1 3 com pared the fracture resi s tance of
endodonti cal l y treat ed teet h restored with cast gold pos t and pin am al gam rest oration. The y concl uded that endodonticall y t reated t eet h with natural crowns demonstrat ed great er st rengt h t han eit her of the two res torat ive t ypes. Pin -ret ained am al gam cores were si gnifi c antl y stronger than cast -gold dowel -cores.
Gu zy GE et al (1979)1 4 compared t he fracture l oads of endodonti call y
treat ed t eeth, with and without endodontic posts t o determ ine i f the post reinforces the root against fracture. The y concl uded that there was no st ati sti cal si gni ficant reinforcement wi th cem entat ion of posts.
Davy DT et al (1981)1 5 utiliz ed the finit e el em ent t echnique t o anal yze
tapered-post diam et er was comparabl e to the c ylindrical post diam et er in the hi gh-stres s regi on. The t apered-post desi gn experi enced sli ghtl y hi gher t ensil e and s li ghtl y lower shear stress es than t he c ylindrical post. Usi ng t he peak st res ses in the denti n and at the dentin -pos t interface as a crit eri on, t he c yl indri cal post wi th the l argest diam et er was the best des i gn.
Standl ee JP et al (1982)1 6 det ermined the st ress dis tri buti on properti es
of t he Dent at us s crew and compared it to t apered s mooth -sided, parallel -s ided serrat ed, parall el -sided t apped threaded usi ng photoel ast ic st ress anal ys is. The y concl uded t hat the tapered, sel f -threading; Dent atus endodonti c s crew causes s evere wedging forces .
Eshel man E G et al (1983)1 7 compared three dowel mat erials and
fracture resist ance of t eeth. The y concluded a progressive load t o a dowel -cont aining tooth wi ll c aus e fracture of t he root .
Reinh ard t RA et al (1983)1 8 Report ed that a parall el -si ded pos t
disperses the st ress es uni forml y along it s length except at t he apex, where t here i s concentration of t he st resses.
Sorens en JA et al (1984)1 9 eval uat ed 1273 endodonticall y t reated teet h
dowel len gt h on t he clinical success rat e. The y concluded the cast parallel -s ided serrat ed dowel and core and t he parall el -si ded s errat ed dowel with an am al gam or com posit e resin core recorded t he hi ghest success rat e. The tapered cast dowel and core di spl a yed a hi gher failure rat e than teeth t reat ed wit hout intracoronal reinforcem ent .
Yazdani e N et al (1985)2 0 concluded from thei r stud y that carbon fiber
acr yl ic resin com pos ites were st ronger and sti ffer than unfi ll ed acr yl ic resin. The strands were more effi ci ent strengt heners than are woven mats . Therefore, it ma y be possibl e to reduce the amount of fiber incl uded.
Coon ey JP et al (1986)2 1 investi gated the ret enti on and st ress
distribut ion of t wo t apered -end posts wit h di fferent em bedment dept hs and post di am et e rs. Under sim ulated functional loads , the t apered -end posts produced wedgi ng st resses near t he apex. More uni form stres s distribut ions were –observed wit h t he parall el -sided pos ts.
Kersten et al (1986)1 0 report ed that shape of t he root canal pla ys an
Leary JM et al (1987)2 2 concluded int ernal toot h st ructure is removed from the tooth m akes it weaker and teeth wi th pos ts do s ho w more rei nforcem ent than non -post ed teet h with the s am e m anipul ati on charact eri sti cs. Som e load t rans fer appears t o exist wi th cemented posts .
Greenf eld RS et al (1989)2 3 compared a parall el -t aperi ng, threaded,
split -shank post with a parall el serrat ed p ost under appli ed com press ive-s hear l oads . The y conclude t hat parall el threaded post was superi or to parall el s errat ed post s in resi sting l oads.
Hunter AJ et al (1989)2 4 examined the effect of root canal
preparati on, post preparation, and posts on the rel ati ve s tres ses i n the cervical and api cal regions of tooth models repres ent ing an i ntact maxillar y cent ral i ncisor b y two -dimensional photoel ectri ci t y. The y concl uded that i f considerabl e enl argement of t he root canal has occurred, a post wi th a moderate diam et er and l ength s ubstantiall y rei nforces the t ooth. Rem oval of int ernal toot h struct ure during root canal therap y is accompani ed b y a proporti onal i ncrease in stress es at the cervi cal area, particul arl y on the t ensi on si de.
Reeh et al (1989)2 5 com pared the effect of endodont ic and restorati ve
from occlus al cavit y preparation and 63% from M OD cavi t y preparati on.
Burns DA et al (1990)2 6 com pared t he st ress di stributi on during
inserti on and functi on of three prefabricated endodontic posts with different desi gns usi ng the crit eri a of post length and di am et er. The y report ed larger di amet er posts at increased dept hs dist ri buted st ress more effi ci entl y t han the sm all er, s hort er posts when obliquel y loaded.
Kin g PA et al (1990)2 7 compared four different t ypes of post core
s yst em. The y concl uded post -ret ai ned crowns using a prefabri cat ed CFRC post exhibit ed properties comparabl e with, and in s o me cas es bett er than, thos e of existing prefabri cat ed m et al post s. The mode of fai lure of s pecim ens restored wit h a C FR C post was m ore favourabl e t o the remai ning tooth tissue than was that of s pecim ens rest ored with a met alli c post
McDon ald AV et al (199 0 )2 8 det ermined the effect on impact fracture
Sorens en JA et al (1990)2 9 det ermined the effect of different post desi gns and var yi ng amounts of post -to -canal adaptat ion on the fracture resist ance of endodonti cal l y t reat ed teeth. Thei r results suggest ed tapered post s resul ted in fract ures that were di rected more apicall y and linguall y. P arall el -si ded pos ts had a l ower frequenc y of fracture upon fai lure, invol ving l es s tooth struct ure.
Wein e FS et al (1991)3 0 conduct ed a ret rospect ive stud y on 51 pati ent s
with 138 endodonti call y treat ed teet h restored with t apered smooth posts . The y concluded when t apered sm ooth posts are us ed properl y, ret entive probl ems do not occur.
Hatzikyriak os AH et al (1992)3 1 compared the ret ent ion of tapered
threaded posts, t apered cast pos ts and parall el s errated cem ent ed posts . The posts t hat had least ret ent ion in t hei r stud y were parallel cemented posts .
Sedgl ey et al (1992)3 2 compared t he biom echani cal properti es
(hardness , toughness , punch s hear st rength and load to fracture) of 23 endodonti call y treat ed teet h with thei r contral at eral vit al pairs. The y found no si gnificant difference bet ween them . However, the changes in pulpl ess t eet h m a y be caus ed b y the restorat ive procedure it self.
Men tink AG et al (1993)3 3 did a ret rospecti ve stud y on 516 t eeth
1990. The y anal ys ed failure charact eristi cs . The y report ed that recem ent ation after l oss of ret enti on occurred mos t frequentl y
Vigui e G et al (1994)3 4 reported that for fabri cation of pos ts and cores,
short carbon fi bers randoml y dis tri but ed withi n t he composit e resi n are recommended. This is comm onl y i mplem en ted b y use of a preimpregnat ed form inj ect ed under pressure and vacuum .
Torb jorner A et al (1995)3 5 compared custom cas t and paral lel -sided
serrat ed post s with respect to t ype of failure and failure rate and evaluat ed pos sibl e background factors. Their resulted a si gnifi cantl y hi gher succes s rat e was recorded for parallel -s ided s errat ed posts , com pared with custom -cas t posts, regarding the t ot al fail ure rate and the severit y of the failure.
Pu rton D G et al (1996)3 6 compared rigidit y and ret enti on in two
different 1 -mm di amet er root canal posts —sm ooth carbon fiber post s and serrated st ainl es s steel post s. The y report ed t hat the st ai nles s st eel posts were more ri gi d than carbon fiber posts.
Mend oza DB et al (1997)3 7 evaluat ed the abi lit y of resin -bonded post s
Nergi z I et al (1997)3 8 det ermined the ret enti ve st rengt h of tapered titanium posts with different s urface t extures and exami ned the effect of roughening denti nal walls of the prepared post space. The smooth post showed the l owest retentive strengt h. Sandbl as ting the s moot h post more than doubled its ret ent ive strength. The retentive s trengt h of both sm oot h and s andbl ast ed posts coul d be further i ncreas ed b y the addition of ci rcumferenti al grooves, roughening the dentinal walls of the prepared post space increased t he ret enti ve st rength of s andbl ast ed posts wit h and without grooves even more.
Dean JP et al (1998)3 9 evaluated the infl uence of endod onti c and
restorative procedures on fracture resi st ance of teet h, and com pared the inci dence of root fracture i n teeth with clini cal crowns removed that were rest ored wit h t hree di fferent t ypes of post and a com posite core build -up. The res ults of t he stud y revealed the group restored with the carbon post had no root fract ures , whereas there were five fractures in each of t he parall el and t apered post groups.
As mu ss en E et al (1999)4 0 det ermi ned t he sti ffnes s, el asti c limit, and
Bae JM et al (2001)4 1 measured the flexural strength and t he el asti c modul us of compos ite res in wi th and without rei nforcing fibers (a pol yeth yl ene fi ber (Ribbond), a pol yara mid fi ber (Fibrefl ex), and three gl as s fi bers (FibreKor, Gl asS pan, Vectris) and to eval uat e the rei nforci ng effect. The y concluded fi bers us ed i n the s tud y increased both yi el d and ul timat e flexural st rengths of com posi te res ins . Unidi rectional gl ass fibers and pol yaramid fiber were effective in rei nforci ng bot h flexural st rength and el asti c m odul us of com posit e resin.
Cormi er C J et al (2001)4 2 evaluated 6 post s yst ems over 4 simul at ed
Ferrari M et al (2001)4 3 evaluat ed the i nfl uence of four adhesive procedures in resin t ag, adhesive l ateral branch and resin dentin int er -diffusi on zone (RD IZ) formation when used t o bond fiber posts. The y suggest ed a microbrush mi ght clini call y be us ed for bondi ng fi ber post s into the root canal. When a microbrush was us ed, the bondi ng mechanism created between root canal dentin and bondi ng s ystem was uniform along canal wal ls and more predi ct abl e.
Raygot C G et al (2001)4 4 evaluat ed the fracture resist ance and mode
of fracture of endodonti cal l y t reat ed incisors res tored wi th ca st post -and -core, prefabricat ed st ainl ess steel post, or carbon fi ber – reinforced com posit e post s ys t ems. Their result s suggest ed t he use of carbon fiber –rei nforced com posit e posts did not change t he fracture resist ance or the failure mode of endodonti call y t reat ed cent ral incisors com pared to the us e of m et alli c post s.
Quintas AF et al (2001)4 5 evaluat ed t he role of s urface t reatm ents
Akkayan B et al (2002)4 6 com pared the effect of one tit ani um and 3 estheti c post s ys t ems on the fracture resis tance and fracture patterns of crowned, endodont i call y treat ed teet h. The y concluded si gnificant l y hi gher failure loads were recorded for root canal treated teet h restore d with quartz fiber pos ts. Fractures that would all ow repeat ed repai r wer e observed in t eet h res tored wit h quartz fiber and gl ass fi ber posts.
Nergi z I et al (2002)4 7 invest i gat ed t he effect of l ength and di am eter
on the retentive st rength of sandbl as ted tapered prefabri cat ed tit anium posts . The res ults of the stud y were retenti on was affect ed strongl y with the increas e in the lengt h (approxi mat el y 100%) than with the increase in t he di am eter (approximat el y 60%).
Pontiu s O et al (2002)4 8 eval uated t he s u rvival rate and fract ure
resist ance of maxill ar y cent ral i ncisors restored with di fferent pos t and core s ys t ems. Sampl es rest ored wi th a cast post and core dem onst rated more verti cal root fractures.
New man MP et al (2003)4 9 compared the effect of 3 fi ber -reinforced
Al-h arbi F et al (2003)5 0 evaluat ed the ret entive st rengt h of com posit e and cerami c endodontic dowel s ystem s to the tooth and to the core foundation. The y concl uded resi n dowel s yst ems were m ore ret entive in the root than the cerami c dowels but were simil ar t o the titani um control.
Malf errari S et al (2003)5 1 did a prospect ive clini cal follow -u p
evaluat ed t he accept abili t y o f quartz fi ber –rei nforced epox y posts used in endodonti call y treat ed t eeth over a 30 -month period. The y concl uded that over a 30 -month period, the rehabili tati on of endodonti call y treat ed t eeth us ing quartz -fiber post s showed good cli ni cal results. No crow n or prost hesis decement ation was observed, and no post , core, o r root fractures were recorded.
Maccari PCA et al (2003)5 2 evaluated the rol e of composition of
prefabri cated est heti c post s in fract ure resi stance of endodonti call y treat ed t eeth in vit ro. T he y com pared t he carbon fiber, gl as s fiber and cerami c post . The y standardiz ed the core b y fabri cating pol yest er mat rices . The y delivered the force at 45 duri ng fracture resi s tance test at t he middle thi rd of t he crown. The cerami c post s had l east fractur e resist ance and associ at ed wi th root fractures. Bot h the carbon fiber and gl as s fiber posts did not have an y root fractures.
Kish en A et al (2004)5 3 investi gat ed the biom echani cal perspective of
experim ent al, and fractographi c anal ys is . Thes e experim ents aided in correl ating the stres s –st rai n response in struct ural dentine wi th crac ks and cat ast rophi c fractures in post -core restored t eeth. It was obs erved from thes e experiments that the inner dentine dis pla yed di sti nctl y hi gh strains (deformati ons), whil e the out er denti ne dem onst rated hi gh stress es during t ens i le loadi ng. This im pli es that the energy fed int o the materi al as it i s ext ended wi ll be spread throughout the i nner dentine, and t here is les s possi bilit y of l ocal i ncrease in st ress at the out er dentine, whi ch can l ead to the fai lure of dentine st ruct ure. During post -endodontic rest oration wit h increas e in los s of inner dentine, the fracture resist ance factor contribut ed b y t he inner dentine is com promis ed, and t his i n turn predisposes the t ooth to cat ast rophi c fracture.
Lassila LV et al (2004)5 4 investi gat ed the fl exural pro pert ies of
different t ypes of FRC posts and com pare thos e values wi t h a novel FRC m ateri al for dent al appli cations. Their results s uggested both carbon and graphit e and gl ass fiber reinforced posts have s imil ar flexural st rengt h.
Sahafi A et al (2004)5 5 eval uated the effect of cem ent , post mat erial,
Galhano GA et al (2005)5 6 evaluat ed the fl exural st rengt h of ei ght t ypes of fiber posts (one carbon fiber, one carbon/ quartz fiber, one opaque quartz fiber, two transl ucent quartz fiber, and three gl as s fiber posts )., b y m eans of the t hree -point bending t est . The y found that the posts behaved simil arl y because of the same concent ration and t ype of the epox y resin us ed to joi n the fibers together. The result s achi eved allow for the suggestion that these mat eri al s would pres ent a bett er respons e to the mas ticator forces if the superiorit y displ a yed on t he direct load appli cati on on the post was considered.
Nagasi ri et al (2005)5 7 dem onst rated that t he survival rat es of
endodonti call y treat ed molars without crowns at 1, 2, and 5 ye ars were 96%, 88%, and 36%, res pecti vel y. The y also found that molar t eet h with greater amount of rem ai ning t oot h struct ure aft er endodonti c treatm ent had a survival rate of 78% at 5 years, and di rect com posit e restorations had a bett er survival rat e than conventi onal amalgam and rei nforced zinc oxide and eugenol with pol ym ethacr yl at e rest orations.
Nau mann M et al (2005)5 8 eval uated the s urvival of glass fibre posts
Balbosh A et al (2006)5 9 evaluat ed the effect of surface treatm ent on the retention of glass fiber endodontic posts l uted wit h res in cem ent and subject ed to artifi ci al aging. Their concl usion was treating th e surface of the posts with ED -Prim er mat eri al before cem ent ation wi th Panavi a F cem ent produced no si gni fi cant improvem ent in t he retention of the post s. Airborne -parti cl e abrasion of the surface of the post si gni fi cantl y improved the ret ention
Diets chi D et al (2006)6 0 evaluat ed t he i nfluence of t he post mat eri al ’s
ph ysi cal propert ies on t he adapt ation of adhesive pos t and core restorations aft er c ycli c m echanical loadin g. The y compared 3 anis ot ropi c posts (m ade of carbon, quart z, or quartz -and-carbon fi bers ) and 3 is otropi c posts (zi rconi um, st ai nles s st eel, tit anium). Their concl usion was R egardl ess of thei r ri gi dit y, m etal and cerami c isotropi c pos ts proved less effect i ve than fiber posts at stabilizing the post and core st ruct ure i n the abs ence of the ferrule effect , due to the devel opm ent of more int erfacial defects wit h either com posit e or dentin.
Fokkinga WA et al (2006)6 1 investi gat ed in vit ro fracture behavi or of
(adhesivel y cem ented) crowns, wit h a li mited ferrule, is independent from t he (adhesivel y cem ent ed) post -and -core s ys tems appli ed.
Mon ticell i F et al (2006)6 2 investi gat ed the infl uence of diffe rent
et ching procedures of t he pos t -surface on mi crot ensil e bond st rength val ues between fiber post s and com posit e core m at eri als. The y concl uded s urface chemi cal treatm ents of the resin phas e of fi ber posts enhance t he sil anizat ion effi ci enc y of t he quart z fiber phas e, s o that the adhesi on in t he pos t/ core uni t m a y be considered a net sum of chemi cal and mi crom echanical ret ention.
Perez BE M et al (2006)6 3 eval uat ed t he infl uence of thi cknes s of
luting cem ent on the bond st rengt h of FRC post s to root denti n. The y report ed from thei r stud y that increase in cem ent thicknes s did not have si gnifi cant effect on bond st rengt h.
Pf eiffer P et al (2006)6 4 evaluated the yi el d st rengt hs of gl ass fibre
-rei nforced com pos ite (FRC) posts and zi rconia dioxide cerami c (ZDC ) posts . The y found t hat t he yi eld st rengt h was si gni ficantl y hi gher fo r the zirconia and t itanium post s when compared with GFR posts.
Stri ck er EJ et al (2006)6 5 eval uat ed marginal adapt ation, fract ure
Teixei ra E CN et al (2006)6 6 conduct ed a stud y to compare the in vit ro ret ention, fracture and li ght transmi ssion behavi or of four different fiber -reinforced resi n -bas ed composit e root canal posts. The y us ed a vee block to simulat e 45 angulat ed force on t he pos ts. The y concl uded that p aral lel fi ber -rei nforced com posit e posts s howed better ret ention than did t apered posts when dual -cured resin -bas ed cem ent was us ed.
Vano M et al (2006)6 7 eval uat ed t he influence of various surface
treatm ents t o fibre pos ts on the mi crot ens ile bond st rength wit h different composite resins . The y concl uded h ydrogen peroxide and h ydrofluori c aci d both modi fi ed t he surface m orphol ogy of fiber posts and with silane, si gnifi cantl y enhanced t he int erfacial strength bet ween them and core m at eri als.
Maccari PC et al (2007)6 8 evaluat ed t he fracture st rengt h of t eeth with
Plotino G et al (2007)6 9 eval uated the flexural modulus and fl exural strength of di ffe rent t ypes of endodontic pos t in com pari son wit h hum an root dentin. Their conclusion was FRC post s have an elasti c modul us that more clos el y approaches that of dentin whil e that for met al posts was m uch hi gher. The fl exural st rength of fiber and metal posts was respectivel y four and seven tim es hi gher t han root denti n.
Seef eld F et al (2007)7 0 investi gat ed t he ultrast ructure and resist ance
to fracture of ei ght different t ypes of fiber post, and t o veri f y the existence of a correl ati on between st ructural charact eri s tics and flexural st rengt h. In thei r stud y a st rong correl ation was found between fiber/matrix rat io and fl exural st rengt h of FRC -post s ys t ems.
Souza RAO et al (2007)7 1 evaluat ed the infl uence of the brus h t ype as
a carri er of priming adhesi ve soluti ons and the use of paper point s as a rem over of the exces s of these solutions on the p ush -out bond strength of resin cem ent to bovine root dentin. The y concluded t he appli cat ion of paper point s to remove excess adhesi ve improved the bond strength for all groups .
Bitter K et al (2008)7 2 evaluat ed the effect s of pretreatm ent
si gni fi cantl y decreas ed bond st rength bet ween all materi al com binations.
D’Arcangelo C et al (2008)7 3
evaluat ed the i nfl uence of endodonti c therap y, veneer preparati on, and their ass oci ation on fracture resist ance and deflecti on of pul ples s ant erior t eeth and ass es s whether restorati on with quartz fiber -rei nforced po st can i nfluence thes e propert ies. Thei r results were suggesti ve of fiber post restorations s eemed to si gni fi cantl y i ncrease m ean maximum load val ues for specim ens prepared for veneers. A fiber -reinforced post restoration can be suggest ed when endodonti c t reatm ent is associ at ed wit h veneer preparati on.
El-Ela OAA et al (2008)7 4 det ermined the fracture resi stance of
endodonti call y treat ed ant eri or t eeth restored with a novel nonm etal lic post i n com bination with s el f -et ching adhesives. The y concluded t hat use of a novel gl ass fiber post was associ ated wit h the hi ghest m ean fracture force for m axillar y ant erior t eeth, regardl ess of the bondi ng agent used, whereas the st ainl ess steel post was ass ociat ed with the lowest mean fracture force.
Ki van ç BH et al (20 08)7 5 investi gat ed t he fracture st rength of three
fai lure loads than teeth rest ored wit h zirconia and ti tanium posts. Sel f -et ching adhesives are b-ett er alt ernatives to -et ch -and ri ns e adhesive s yst ems for l uting post s ys tems.
Meh ta SB et al (2008)7 6 evaluat ed t he out comes of a fiber post
cemented wit h two different luting agents. The y concluded that the most comm on caus e of fai lure was m echanical fracture at the post -core interface. The mechanical fai lures due to fractures occurri ng along the length of the post -core compl ex were a major caus e of concern, t he majorit y of m echani cal fail ures associ at ed with the us e of fibre posts were non-cat ast rophic, am enabl e t o repai r and prot ective of t he rem ai ning tooth structure.
Soares CJ et al (2008)7 7 evaluat ed t he effect of cavit y desi gn and gl ass
fiber posts on st ress dist ributions and fracture resist ance of endodonti call y treat ed premol ars. Stres s distri buti ons were evaluat ed for each group in a two dim ensi onal finit e element anal ysis. The y concl uded t hat the l oss of dental struct ure and t he pres ence of fiber post restoration reduced fract ure resist ance and created hi gher st ress concent rations in the tooth -restoration compl ex. However, when there was a large l oss of dental structure, the post reduced t he incidence of catastrophi c fract ure t ypes.
Sahafi A et al (20 08)7 8 charact eriz ed and anal yz ed report ed failures of
t ype of fail ure. The y concl uded t hat t apered post s were associ at ed with a hi gher risk of tooth fract ure t han were parall el -si ded posts .
Wang Y et al (2008)7 9 eval uat ed influence of C -fact or on the
microt ensi le bond st rength bet ween fiber posts and resi n luti ng agents. The summ arized that the i nfl uence of a clini call y rel evant cavi t y confi gurati on on the adhes ion establis hed b y t wo resin cem ents on gl as s fiber posts was not st atisti call y si gnifi cant.
Zhan g L et al (2008)8 0 evaluat ed the effect of different curi ng m odes
(―Self-cure and Self-cure (SC&SC)‖, ―Self-cure and Dual-cure (SC&DC)‖, and ―Dual-cure and Dual-cure (DC&DC)‖) of dual -curing luting s ys t ems and root regi ons on the pushout strength of fi ber post s to intraradicul ar dentin. The resul ts concluded t hat t he photoi rradi ati on of dual curing resin cement aft er post cement ati on improved the push -out st rengt h of t ranslucent fi ber post s t o int raradi cul ar dent in, whi ch was dependent up on the t ype of resi n cem ent .
Buttel L et al (2009)8 1 invest i gated (i) the impact of FRC post fit
post s pace preparati on aimed at produci ng an optim al circumferenti a l post fit is not required to im prove fracture resist ance of roots.
Dorri z H et al (2009)8 2 compared the fract ure res istance of
endodonti call y treat ed t eet h rest ored with di fferent post and core s yst ems in combinat ion with complet e met al crowns in teet h wi th no coronal st ructure. In their st ud y the prefabri cat ed gl as s fiber post with com posit e core group showed the most favorabl e fracture pat tern in all test groups.
Sch mage P et al (2009)8 3 com pared the bond s trengths of fi ber
rei nforced composit e post s lut ed into over sized dowel s paces wit h FRC posts lut ed into precis el y fitti ng dowel s paces usi ng five di fferent resin cem ents or build -up composit es. Bas ed on their results t he y concl uded retentive bond st rengths of FRC post s s howed si gnificant reduction if t he y were i ns ert ed into over sized dowel s paces com pared with precis e fitti ng dowel s paces.
Signore et al (2009)8 4 stat ed that the choi ce of appropri at e definiti ve
The preparation of a pos t space si gni fi cantl y weakened endodonti call y treat ed t eet h. A post di d not si gnifi cantl y s trengt hen endodonti call y t reated t eet h.
Fernando Mass a et al (2010)8 5 ass essed the influence of post -and -core
s yst ems on the resist ance to fracture of mandibul ar premol ars restored with m et al crowns and a 2.0 -mm cervi cal ferrul e. The y concl uded that the restoration of mandibul ar p rem ol ars wit h composit e resin core (wit hout pos t) s howed an increased resist ance to fract ure when com pared wit h other post -and -core s ys t em s whenever a minim um of 2.0 mm of remaining t ooth struct ure was covered with a full m etal crown (ferrule effect ). P res ervation of t ooth struct ure was t he most important fact or in t oot h resist ance.
Poskus LT et al (2010)8 6 assessed the infl uence of post pattern and
resin cement curing mode on t he ret ent ion of gl as s fi bre posts. The y concl uded that the ret ention of gl as s fibre posts was not affected b y post desi gn or s urface roughness nor b y resin cement -curi ng mode. The choice of s errat ed posts and sel f -cured cements i s not relat ed to an improvement i n retention.
Prab eesh Pad manabhan (2010)8 7 compared the fracture resi st ance and
pre-fabri cat ed stainl ess st eel pos t exhibited a si gni fi cantl y hi gher fracture resist ance at fail ure when com pared with the carbon fiber post and the ceramic post . The mode of failure of the carbon fiber post was more favorabl e t o t he rem aini ng t oot h struct ure when com pared with the pre -fabri cat ed st ainl es s st eel post and the cerami c post .
Bitter K et al (2012)8 8 evaluat ed the e ffect of cl eaning method, l uting
agent and preparati on procedure on the ret ention of fibre posts. The y concl uded that di fferent cl eani ng methods did not lead to s igni ficant differences in root canal cleanliness and did not enhance fibre pos t ret ention inside t he root canal. However, post space preparation usi ng a Round Bur mi ght be benefi ci al for im proving retention, especi all y when sel f -adhesive cem ents are used.
Vassiliki Nova et al (2013)8 9 evaluat ed t he pull -out bond st rength of a
fibre-reinforced com posit e post s ys tem l uted wit h sel f -adhes ive resi n cements. The y concluded that different resin cements infl uenced the pull -out bond st rengths, whereas the cement thi ckness its el f was not responsibl e for an y differences. The y al so report ed that Sel f -adhesive resin cem ents can provide an acceptable ret ention of FRC pos ts even in case of use wi th wider post space conditi ons.
Andreas Th omas et al (2014)9 0 evaluat ed th e i nfl uence of post surface
adhesi vel y lut ed quartz fiber reinf orced compos ite posts t o bovine root canal dent in.
Xiao -jing Li et al (2014)9 1 eval uat ed the Effect of luting cement and
thermom echani cal l oading on ret ent ion of gl as s fi bre pos ts in root canals. The y concl uded t hat Resin -modifi ed gl as s ionomer cements have the pot enti al benefit of achieving l ong -term ret ent ion when us ed for luting gl ass fi bre pos t to root canal denti ne. So it ma y be recommended for the cem ent ation of gl ass fibre post in cli nics.
Sebnem B egu m T urker et al (2016)9 2 det ermined the fract ure
MATERIALS AND METHODS
Materi als u sed :
Tooth preparation :
Diamond di sc
Strai ght hand pi ece (NSK EX - 6) S.No: F6X44766; J apan
Micro -mot or NS K EBB75900
Ruler
Cleaning and sh api ng:
K-fil es (M ani Inc, J apan)
Size 10 – Lot No: R16H067100
Size 15 – Lot No: R161023500
Size 20 – Lot No: R15I008300
Prot aper rot ar y fil es – Lot No:1289192
EndoMate DT NS K model MP F I6R C871001
Mini Endo Block (Dents pl y M aill efer, Ballai gues)
Sodium H ypoChlorit e 5.25% (C omdent corporati on, Mum bai )
PulpDent 17% EDTA (Pul pdent Corporati on USA)
Saline (Baxter, Tam i lnadu, Indi a)
Obturati on:
ProTaper Gutt a – Percha points (Dentspl y Mail lefer, Bal lai gues) F3 size - Lot No:1771371
Pluggers (Dent spl y Maill efer, Ballai gues ) Lot No: 1160346
GP holding t weez ers (Sun, germ an y)
Pos t endodon ti c res toration :
Fiber Pos ts Tested
EverSti ck Gl as s Fiber Post(GC ) Lot No : 1411181
Macrolock oval Fi ber Posts (RTD) Lot No: 323541609
Rel yX Fi ber post (3M ESPE, France) Lot No: 70201138800
Luting Cemen ts
G-C EM (GC ) lot No: 1504221
Rel y X U 200 (3M ESPE, Germ an y) Lot No: 625134
Sealbond Dual C em ent (R TD, France) Lot No. 328481610
Materi als for core b uildup
Scot chbond Multi - P urpos e Etchant Lot No: N714933
Spectrum Bond Nano technology Dent al Adhesi ve Lot No: 1503000
Compos ite resi n : Lot No: N642334
Li ght cure unit
Compos ite ins trument (Dispodent )
Vacuum adapt us s yst em and m at rix
DP I – RR Cold Cure (DP I, Mum bai ) B.No: L -61515
Aquasil LV (d ent spl y) Lot No. 150409
Gloves & m as ks
Fractu re resi stance test:
Met al m oul ds t o fabricate resi n blocks
Met al block to hold t he specimens
Fig -1 Armamentari u m for p rep arati on of samp les and
Cleaning and sh api ng
[image:49.595.126.473.126.431.2] [image:49.595.134.462.485.760.2]Fig -3 Armamen tari u m for Post endodontic res torati on
Fig 3.1- Everstick Post
[image:50.595.176.422.99.274.2]Fig 3.2- Everstick Post and drill
[image:50.595.177.425.494.679.2]Fig 3.4- RelyX Post
Fig 3.5- RelyX Post and drill
Fig 3.8- Macro-Lock Oval Post and drill Fig 3.7- Macro-Lock Oval Post
[image:52.595.164.434.535.703.2]Fig 3.8- Macro-Lock Oval Post and drill
Fig -4 Armamen tari u m for core buildup
Fig -5 Armamentarium for Model Preparation
[image:53.595.55.565.321.487.2] [image:53.595.63.567.548.729.2]Preparation of Sp eci men s:
60 extract ed single rooted human m andibul ar premol ars with oval canal s si milar root dim ensions were incl uded i n t his st ud y. The teeth with extrem el y curved roots , fracture lines , s everel y cal ci fied root s and root cari es were excluded from the stud y. The t eeth sam pl es were stored in sali ne until all the requi red speci mens were coll ect ed. The eval uation of the oval canals was done b y t aki ng radiograph in the laboilingual as pect and m esi odis tal aspect of each t ooth. The ratio bet ween the l ong and the s hort canal di am eter at 5mm from the apex was cal culat ed. A rat io >2 i ndi cated t he presence of oval canal .1 0 4
The s amples were sectioned just below the cem ent o– enamel junction with di amond dis c under coolant, such that the rem aining root length will be 13 1 mm.8 1
Endodonti c T reatment:
The canal pat enc y was checked and working l ength was det ermined with 10 K - fil e. The worki ng length was det ermined with a 10 K –file. The fil e was int roduced into the canal until it was seen at the apex. From that length 1mm was reduced and t aken as working length.9 3
irri gated fr equent l y with 5.25% sodium h ypo chlorite and 17% EDTA and fi nall y ri ns ed wi th s aline.
The canal was dri ed and t he obturation was done with Prot aper Gutt a-P ercha (Dent s pl y) and EndoR ez (Ultradent ) s eal er.
The t eeth w ere s tored i n s aline at room t emperat ure for the seal ers t o set. The obturati ng m at eri al was rem oved to 8 mm with th e heat ed pluggers in order to prepare post spaces.
The t eeth s am ples were divi ded i nto 3 groups (n=20) .
Group 1 : Evers ti ck Fib er Post (GC)
Everst ick post (Fi g -3.1) is a soft and flexible, t hus adapt able, pol ym er and resi n i mpregnat ed unpol ymerized glass fi ber post. The post adapts t o the morphol ogy of the canal. The root canal area are com plet el y fill ed wi th eversti ck posts. For this re as on the adhesi ve surface and the st rength in t he most cri tical part of t he tooth i s maximized.1 0 7
Group 2: Rely X Fib er Post (3M ES PE )
properti es the gl as s fibers have parall el ori ent ati on and are distri but ed equall y over the s urface area.1 0 8
Group 3: Macrolock Oval Fib er Post (RTD)
Macrolock Oval Pos t (Fi g -3.7) is a “h ybri d” post desi gn for t he restoration of wi de, fl ared canal s. The unique OVA L shape provides anti -rot ation benefit, whil e repl acing weaker cem ent with hi gh strength fiber compos ite. Pas sive grooves l ock into the cem ent in t he R OUND api cal portion of t he post. Oval fiber posts are preferabl e t o ci rcular fiber pos ts in oval -s haped canals , gi ven the stress dist ributi on at the post - dentin int erface.1 0 9
Pos t Endod onti c Restoration :
The api cal diamet ers of the posts were kept co nst ant as 0.9m m. The post s paces were prepared using respective drills suppli ed b y the manufacturer.
Table 1: Fib er posts with thei r resp ecti ve shap e and lutin g cements
S.NO POST
SHAPE O F
THE POST
LUTING CE ME NT
1 Everst ick fiber post (GC ) Fl exible G-C EM (GC )
2 Rel yX fiber post (3M EPSE) Round Rel yX U 200 (3M ES PE)
3
Macrolock Oval fi ber post (RTD)
Oval
Fig 8- Tooth samples before and after decoronation
Fig 7- labiolingual and mesiodistal view of the samples for evaluation of oval canals
Fig 9 – Obturated samples
[image:59.595.191.452.447.730.2]The posts were lut ed wit h the respective dual cure resin cement (Eversti ck post -GC EM, Rel yX post – Rel yX U -200, M acrol ock oval
post - Seal Bond). The post s were seat ed with finger pressure for 10 seconds and then excess was wiped off and li ght cured for 40 seconds using li ght cure unit.
Each group was then divided into 2 subg roups (a&b) n=10 for fracture res ist ance and ret ention t ests respectivel y.
For fracture resist ance t est core build up was done wit h direct com posit e and li ght cured. The m at rix was adapt ed over the core usi ng vacuum adaptus s ys t em. Using thes e mat rices core bui ld up was done for the rest of t he s amples. The ret enti on test did not require an y core build up. 4 6 , 5 2
[image:60.595.117.476.485.671.2]Artifi cial Peri odon tal Ligamen t:
To simul at e periodontal li gam ent fi rst t he roots were covered with uni form la yer of wax 2mm bel ow cervi cal m argin and im mersed i n the s elf cure acr yl ic resin in the custom fabri cat ed m et al moul d of size 2.52.52.5cm .
The res in blocks were de -waxed b y imm ersing them in hot water. The li ght bod y impressi on m at erial (aqua sil LV, Dentspl y) was mixed and coat ed over the root s and t he teeth were repositi oned i n the resin blocks such t hat 2mm of the root protruding out of the block, the excess m at eri al was rem oved. 6 8
Total number of specimens
(n=60)
Group 1 Everstick post
(n=20)
Group 1a (n=10) Fracture resistance test
Group 1b (n=10) Retention test
Group 2 RelyX post
(n=20)
Group 2a (n=10) Fracture resistance test
Group 2b (n=10) Retention test
Group 3 Macrolock Oval post
(n=20)
Group 3a (n=10) Fracture resistance test
Fractu re Resis tan ce Tes t:
To hold the resin at 45˚ an gulations a metal block was fabricated (fi g-6). The resin blocks wit h the t eeth were mount ed on t he m etal blocks and s ubj ect ed to stati c com pressive load at 45 angul at ions at a cross head speed of 1mm/minut e usi ng universal t esti ng machine (LR100K, Llo yd) (Fi g 15), until there was a sudden drop of t he s tress -strain curve. The load to fract ure was m easured.8 2
The location of fail ure in all samples was recorded. When the teeth exhi bit ed verti cal or oblique fractures extending i nto or below the surroundi ng acr yl i c resin block, the fract ure was consi dered to be unfavourabl e and no restorabl e. Fractures of the tooth above the acr yli c resin block were considered rest o rabl e and more favourabl e.6 8
Retenti on T es t
The resin models were held in the t est ing m achine and t he posts were extract ed us ing vice cl amps m ounted in the univers al t esting machine operated in tensil e mode at 1m m/min (Fi g -16). The direct ion of tensil e loading was parall el to the long axis of the toot h. The dat a were recorded in Newtons. Modes of fail ure were also noted.8 9 , 9 0
Statis tical Anal ysis :
Fig 12 - sampl es for fractu re res istan ce test
Group 1a Everstick Post
Group 2a Relyx Post
[image:63.595.151.473.125.318.2]Fig13- Samp les for Retenti on T es t
Group 1b Everstick Post
Fig- 15 Fracture resistance test
FL OW CHART FO R FRACT URE RES ISTANCE TEST
fracture resistance of each group was evaluated using universal testing machine Specimens mounted on resin blocks with simulated periodontal ligament
Core build up done with direct composite Posts luted with dual cure resin cement
Post space preparation done with drills provided by the manufacturer. Obturation done using ProTaper GP F3 size and EndoRez resin sealer
FL OW CHART FO R RE TENTI ON T E ST
Retention of each group was evaluated using universal testing machine Specimens mounted on resin blocks
Posts luted with dual cure resin cement
Post space preparation done with drills provided by the manufacturer. Obturation done using ProTaper GP F3 size and EndoRez resin sealer
RESULTS
RESULTS O F FRACTURE RESISTANCE TEST
Indi vidual fract ure resist ance val ues are displ a yed i n t abl e 2 and stati sti cs of the fracture strength values of the experim ent groups are displ a yed i n t abl e 3. The resul ts showed that t he fract ure resi stance of group 3a (M acrolock Oval Post) was si gnifi cantl y hi gher than the other two groups . Group 1a (Eversti ck Post) had the leas t fract ure resist ance. Group 2a (R el yX Post) was also st ati sti call y si gni fi cant than group 1a and 3a.
Failu re M odes
Table 2: Fracture Re sistan ce of th ree G roups in Newton(N)
Group 1a
(Eversti ck )
Group 2a
(Rely X)
Group 3a
(Macrolock)
488.59 540.68 592.13
501.60 548.28 590.52
482.61 538.05 589.49
483.77 537.12 596.93
490.78 550.89 598.62
479.34 539.72 609.38
475.47 530.15 588.77
505.51 534.20 594.98
489.18 532.17 586.07
[image:70.595.92.506.467.614.2]481.98 542.06 592.19
Table 3: Statistics for Fractu re Resis tance values
(on e-way ANO VA T es t)
Groups n Mean SD F-valu e p-valu e
Group 1a 10 487.88 9.522
473.071 0.000
Group 2a 10 539.33 6.595 Group 3a 10 593.90 6.640
Table - 4 Failu re Modes of each Group
Group 1a Group 2a Group 3a
Favou rab le 5 6 8
Unfavou rabl e 5 4 2
Intergroup Comparison (Tamhane’s Post Hoc Test)
Table – 5 Fracture Resis tan ce of Grou p 1a Vs Group 2a
Mean SD Mean
difference
Standard error
P value
Group 1a 487.88 9.522 106.025 3.67 0.000
Group 2a 539.33 6.595 54.576 2.95 0.000
p < 0.05 Group 1 a i s stati sti cal l y s i gni fi cant than Group 2 a
Table – 6 Fracture Resis tan ce of Grou p 1a Vs Group 3a
Mean SD Mean
difference
Standard
error P value
Group 1a
487.88 9.522 51.449 3.66 0.000
Group 3a 593.90 6.640 54.576 2.95 0.000
[image:71.595.95.504.107.208.2] [image:71.595.87.508.291.409.2] [image:71.595.85.511.491.626.2]Table – 7 Group 2a Vs Group 3a
Mean SD Mean
difference
Standard error
P value
Group 2a 539.33 6.595 51.449 3.66 0.000
Group 3a 593.90 6.640 106.025 3.67 0.000
[image:72.595.80.517.74.220.2]RESULTS O F RET ENTIO N TEST
[image:73.595.134.462.338.632.2]Indi vidual retention val ues are di spl a yed in tabl e 8 and st atis tics of the fracture st rengt h val ues of the experim ent groups are displ a yed in tabl e 9. The resul ts showed that the ret enti on of group 3b (Macrol ock Oval P ost) was si gni fi cant l y hi gher than the other t wo groups . Group 1b (Everst ick Post ) had the l east ret ention. Group 2b (Rel yX Post ) was als o st atisti call y si gni fi cant t han group 1b and 3b.
Table 8: Reten ti on of th ree Groups in Newton (N)
Group 1b
(Eversti ck )
Group 2b
(Rely X)
Group 3b
(Macrolock)
84.12 142.15 164.38
83.22 138.20 160.48
79.17 139.22 168.17
84.78 140.43 165.12
88.18 144.52 163.30
86.88 143.78 162.89
80.43 145.49 167.71
84.19 142.09 159.14
87.09 138.94 170.22
