From: Valeri Stefanov
To: ROOTS
Sent: Saturday, June 12, 2010 7:54 PM
Subject: [roots] Re: [roots] after Marga´s lecture I want more and more and more...

Javier, Marga already wrote about conventional/classic treatment for a case like yours.

Let me give you an alternative approach which is easier to perform and not so technically sensistive while having
the same predictability and chances for success.

One would fill the canal and area of resorption inside it at one and  the same time by using bioceramic sealer - iRootSP.
It is much more easier to do compared to filling with MTA Marga's way. You can fill totally the canal also with MTA using
Dr.Kossev's method. The difference is that with pure bioceramic it can be done much more easily and for shorter time.
With this method there is no need for wet cotton pellet to be left over the material.

Afterwards wait for at least 24 or preferably 48 hours. On next visit drill out bioceramics with long neck round diamond
bur up to the end of resorption deffect. Take care not to remove a sound dentin from the walls.Then etch with the liquid
of phosphate cement the walls of the "hole" you have created for at least one minute. Rinse with water and then prime and
bond the routine way. Then pack the canal "hole" with very strong fiber re-inforced composite Nulite F (see attached files )
placing it in small portions and light curing each portion before adding a new one. Packing the canal and making a core/build
up is done at the same time - i.e. you make something similar to cast metal core, but this is done "ex tempore" with
very strong composite in one visit. ( see the photo of lateral incisor I have done although I have not got that deep into
the canal )

Finally take impression and make a crown or send the patient to a GP/prosthodontist to make it.

I am using Nulite F since 2004 with great success in similar cases where canal diameter is very big and also for posterior
MOD fillings. If you want additional re-inforcement you can use fiber glass or polyalken tape instead of big size FG root post.
This will give you more even distribution of stress under load compared to using stiffer fiber post instead.

My 2 cents. - Valeri Stefanov



3096 Fatigue failure of teeth restored with composite resin post/cores
C. DOTCHIN, Otago University, Dunedin, New Zealand, and J. HOOD, Otago University, Dunedin, New Zealand
Impact fracture has frequently been used to study the failure of various post/core restoration supporting cast
metal crowns. An alternative clinical failure mode is by fatigue. Objectives: The advent of high modulus,
high fracture toughness fibre composites (Nulite F, SDI Australia) raises the question whether these materials
alone could be used for post/cores supporting crowns. This study seeks to answer this.

Methods: Sixteen central  incisors were decoronated and root canals opened to 1.5mm. Cast metal post/cores and
cast crowns were prepared  for eight teeth. Post/cores and crowns were cemented with zinc phosphate cement
(Shofu Hy Bond). Root canals of  the remainder were treated with 3M Single-Bond and packed with Nulite-F composite
to form post and core.  Metal crowns were then fabricated and cemented. Strain gauges were cemented across the
tooth-crown junction on  the palatal and connected to an electronic strain gauge digital read-out. Teeth were
supported in resin 30 degrees to the horizontal and loaded at 37cycles/minute under 100 N force until failure
or a maximum of 300,000 cycles.

Results: The mean cycles to failure for crowns with cast metal post/cores was 57047 ± 19381. No crowns with
composite cores failed by the "cut off" point of 300,000 cycles. A t-test gave a probability of p=0.0000.

Conclusion: This technique provides a simple, but time consuming method for the study of the failure of crowns
with varying modes of support, under fatigue loading.
Seq #334 - Restoration of Endodontically Treated Teeth
10:15 AM-11:30 AM, Saturday, 13 March 2004 Hawaii Convention Center Exhibit Hall 1-2
Back to the Prosthodontics Research Program
Back to the IADR/AADR/CADR 82nd General Session (March 10-13, 2004)

Comparison study of two posterior composites  in endodonticaly treated maxillary premolar with
mesio-ocluso- distal cavity before and after mounting in an artificial mouth

* k Amiri, F Zakavi, T Omidi pour, Z Jalali
SMJ 2009; 8(1):23-23
ICID: 889423 Article type: Original article IC Value: 4.81

Objective: There are many restorative designs for root canal treated maxillary premolars that each of which have
their own advantages and disadvantages. One of this treatments is composite inlay restoration with fiber-reinforced
composite which has sufficient retention, strength and acceptable apearence,as well as more compatibibility and
less leakage than cast-metal restoration.

Material sand Methods: In this -experimental study, after calculating a sample groups, 72 sound maxillary premolar
teeth with the same size were chosen and fixed in acrylic resin so that the CEJ was 2 mm upper than the level of resin .
the sample were randomly divided in to six groups of 12 .

Group 1(positive control) : intact teeth. Group 2 (negative control): root canal treated with MOD cavity preparation
that had been extended 1 mm below CEJ . Group 3 and 4:root canal treated teeth with MOD cavity preparation for
fiber- reinforced (Nulite F) composite inlay using Nulite F2 liner . Group 5 and 6: these groups were prepared
in the same way as groups 3 and 4, differing in that , this specimens were restored by 3MP60 composite instead of
Nulite F . Following restoration , all specimens was termocycled 500 times. Specimens of groups 1,2,3,5 were loaded
by the universal testing machine (Zwick z020,Germany) at speed of 0.5 mm/min. specimens in groups 4& 6 onset were
loaded by artificial mouth 1000,000 times then loaded by universal testing machine . Finally the results was analyzed
using ANOVA test and comparison multiple tests.

Results: average fracture resistance for first group was 2.091 killo nioton,(kn) second group was 0.862kn, third group
was 1.577 kn, fourth group was 1.431 kn , fifth group was 1.296 kn and sixth group was 1.170 kn. According to data
analysis the deference between first and secovd groups to other groups was significant. Fracture resistance of 3th group
with 5 &6 groups and 4 th group with 6 group have significant deference.

Conclusion: because of increasing of the fracture resistance in endodontically treated teeth that restorated with
fiber-reinforced composite (Nulite F) and their significant diference in comparison with conventional posterior
composite (3MP60) as well as their other properties , can say that we can use fiber reinforced composite as an
acceptable method for reconstruction of endodontically treated maxillary pre molar.