AMAZON PROJECT

Creation and Development: Manoel Eduardo de Lima Machado, DDS, MDSc, PhD

Collaborators: Caio Eduardo Caseiro de Lima Machado, DDS

Felipe Britto de Lima Machado, DDS

Associate professor at School of Dentistry, University of São Paulo (Brazil)

Post-Doctoral at Harvard School of Dental Medicine

(USA)

Professor of the Master and Doctoral Degree’s Program at School of Dentistry, University of São Paulo (Brazil)

President of the Brazilian Endodontic Society (SBENDO)

President of the Latin American Society of Endodontics (SELA)

Proposal: To evaluate the Performance of an Endodontic Protocol used in

Adverse Situations.

PROBLEM

One of the most critical issues observed in third world countries or other

classifications is financial or social issue.

It can be observed in daily life of big cities, in the absurd convention

systems and in the suburbs and countryside of course. Therefore, it is

fundamental mission of researchers to develop a protocol of endodontic

treatment easy, quick, simple, low cost and high quality, with proposals to

transmit health and dignity to the people. After all, that is why we were trained.

Thus, the "AMAZON PROJECT" was created.

THE IDEAS OF POSSIBLE SOLUTIONS

Reduce the number of sessions, technical ease and simplicity in

resources and equipment would be great aids in improving the cost-benefit

ratio.

PILOT TESTS

At first, the new rotary systems seemed to engage in this proposal, and

thus different rotary systems were tested by professors and graduate students.

After A series of tests observing: cutting, strength, care and company support,

and durability, the ProTaper system was selected.

Once selected the system, a series of research observing disinfection,

modeling and other requirements related to the preparation of the canal were

performed. Once good results had been demonstrated the system is now used.

In Vitro moment (1998):

-Graduate students began use in artificial mouth with extracted human

teeth and subsequently testing was applied to undergraduates. The technique

used was that suggested by the manufacturer. In developing this work can be

seen a considerable rate of fractures especially in the transition from S2-F1 or

F1-F2, such a fact has been solved with the use of Gates-Glidden prior to

rotating on the cervical and middle thirds and hand files up to 25 on apical

region. Then, the number of uses of systems has to be expanded to 10 or more

molars and fractures were rarely observed.

These observations include treatments in number higher than 2000

upper and lower molars. Another feature observed was that these treatments

fillings allowed 99% of the time with just a cone 06, which completely filled the

canal. This obturator technique can have its efficiency proved after a series of

tests.

(Caution: the system hybridization was performed to allow use with a greater

number of times of the system for better cost effectiveness ratio and increased

safety)

THE TECHNIQUE

By analysis of the observations in 2003 was published the following technique:

Hybrid technique using the ProTaper (Machado 20030

The concepts related to the use of this technique are explained and

justified in textbook Machado MEL. Endodontia da biologia a técnica, 2007.

All this technical procedure is linked to the principle of passive pressure,

and the preparation is divided into two stages: The first associated with handling

of the cervical third, middle and beginning of the curvature and the second in

the apical region.

Step 1

a) Preparation of canals’ entries with Gates Glidden and ProTaper SX;

b) Apical cervical preparation with Gates Glidden drills numbers 1, 2, 3;

c) The canal must be searched with a 15 or 20 file to 2 mm of the root

radiographic end; such a measure is obtained in the analysis of diagnostic

radiography;

d) Use of rotary instruments SX and S2 is accomplished with the following

characteristics: to introduce the instrument into the canal with the instrument

coupled to the handpiece and motor off to the depth that it presents a feeling of

being locked inside the canal, then retreating from 1 to 2 mm until it is fully free.

Drive the engine that should be calibrated at a speed of 350rpm and a torque 4.

With the free tool and the driven engine, the kinematics should be brushing on

all the walls of the canal; subsequently, repeat the maneuver in order to

penetrate a bit more within the canal must, however, being noted that these

instruments will work totally free inside the canal.

Step 2

Preparation of the apical region - this time we will access and work the

apical region of the canal and therefore, the following procedures are observed:

a) Working length determination;

b) Access and enlargement of the apical region with hand files 15, 20 and 25 in

the working length;

c) Preparation with rotary instruments S1, S2, F2 F1e at a speed of 500 rpm

and torque 4 N.cm up to working length.

At this stage we should note the following items

All instruments should access the working length with continuous in-and-

out motion, i.e. we should never use a rotating device stopped at the same

point. This action is of paramount importance, since an instrument working with

cutting action stopped in the same region has great potential to fracture or

formation of gaps or steps. Thus, the kinematics applied is in-and-out motion up

to working length, not needing to apply forces on the side walls and this

kinematics should only be performed three times.

The shaping completion with F2 instrument in buccal roots of upper molars

and mesial of lower molars allows the professional uses a cone 06 with tip #30

or #35, which is considered sufficient shaping for these canals. In palatal or

distal roots of lower molars the shaping should be made with F3 or F4 using

cones #45 or #50 taper 06.

Observation:

Apply the Principle of Passive Pressure. In working with this technical

protocol we observed that the transition of S2 to F1, F1 to F2, and F2 to F3, we

can find it difficult, because often the instrument is positioned away from the

working length. The insistence on its use coupled to the motor will lead to

fracture, thus the professional conduct must be:

a) Re-use over the 3 Gates Glidden or penetrate with the same instrument

manually applying ¼ spins and occlusal traction until it reaches the working

length. Once positioned, maneuver is continued until the instrument can give a

full 360 degree turn.

b) That said, we can use it driven in the engine with the aforementioned

kinematics. The example used here should not be limited to the diameters

mentioned but every time an instrument does not reach the working length, it

should be manually used before its driven motor use. However, when launching

the Protaper Universal®, this maneuver came to be performed sporadically.

Single-cone technique: Given the characteristics of shaping it is common the

root canal obturation using a single-cone technique with a taper 06 gutta-

percha cone. It is also observed that given the large cutting action of these

systems, the cone size is one or two times higher than the last files used for

instrumentation, and if we conclude the preparation with the F2 (tip 25), the

canal will be filled with a taper 06 #30 or #35 gutta-percha cone. If necessary,

the professional may use accessory cones.

DESIGN: Given the excellent technical results regarding the quality, clinical

success (shown in observation of pre-observed cases within 2 years), reduced

working-time, ease of learning and application, we test the procedure in

extreme and adverse conditions.

NAPRA Project:

This project aims at meeting the riverine populations of the Amazon

River. Thus, medical, dental, psychological care, concepts of public health and

other health areas are held during the month of July with a group of

professionals and student volunteers. The project is private, with limited

sponsorship and all resources are personal or donated.

Participants leave São Paulo for a 4-day trip by bus, after boats and

leave to meet in places where the government is absent or has little contact.

Professionals and students are divided into groups for the different works.

We created the action of Endodontics in this project, whereas previously

only extractions were performed.

Thus with flashlights, apex locators, rotary systems, RX, auxiliary

chemical substances and single-cone fillings, treatments were performed.

About 3 years, 4 students coursing specialization and 4 undergraduate

students could accomplish in 3 trips, 185 molar root canal fillings with different

pulp and periapical pathological conditions (vital pulp, apical necrosis with and

without injury). Worth pointing out that given the circumstances the treatment

were conducted in single session avoiding the extraction of these teeth.

Result:

The return and public participation was significant, in such a way that the

evaluation or observation after return of 120 cases could be performed in last

July. Only 8 of these cases were extracted by staying with apical lesions while

all other had bone repair.

THE FUTURE PROSPECTS

Once demonstrated the procedure efficiency, apply it further in private

clinics to enhance the cost-benefit ratio, and initiate projects in the public and

military health.

The project is now being implemented throughout Latin America in

collaboration of the associated countries in SELA, and it will showed during the

SBENDO International Congress / SELA Meeting on November, 2014 at São

Paulo, Brazil.

PHASE 2 (2014) - Brazil

Use of Technology in Endodontics under Conditions of Extreme

Difficulties

The Amazon Project 2014 remains true to the same proposal since its

inception: to test the practicality of new and useful technologies under

conditions of extreme difficulties. Currently, 15 years after, the scientific support

is highly significant as can be seen in the bibliography.

This year the project enters its second phase, significantly modifying its

technical protocol.

The region chosen was Nazareth, located on the banks of the Rio

Madeira and Cumia Lake, a lake formed by a tributary of the Rio Madeira in

Rondônia.

History:

-From São Paulo to Porto Velho -Rondônia

-Rondônia - Riverside Community of Nazareth - 7 hours by boat upwards the

Rio Madeira.

At the moment we arrived, Nazareth was partially destroyed by a great

flood of 18 meters from Rio Madeira that made homeless several residents.

Staff accommodation

Preparation to clinical care

TREATMENT

Patients presenting with acute pulpitis and / or deep caries or even pulp

necrosis without bone rarefactions worthy of note or edema were selected for

endodontic treatment.

Due to the distance and impossibility of continued treatment, these cases

were performed in one session following the protocol bellow:

1 – Initial X-ray with emitter and portable digital device (figs 1 and 2).

FigurE 1 – Digital sensor to periapical radiograph

Figure 2 – Portable digital X-ray device

2-Apical access using Proglider rotary file (Dentsply Maillefer, Ballaigues,

Switzerland) in the working length of 2 mm below the apparent length of the

tooth (the technique will be described in further details below).

3- Preparation with Wave One reciprocating file (Dentsply Maillefer) compatible

to the root canal diameter, auxiliary chemical substance - urea peroxide (Endo

PTC leve, Formula & ação, São Paulo, Brazil), neutralized with 2.5% sodium

hypochlorite (Formula & Ação) and irrigation with 5 ml of 2.5% sodium

hypochlorite enhanced by ultrasonic activation using Endoactivator (Dentsply),

followed by irrigation with 5 ml EDTA-T (Formula & ação) also sonically

activated.

4 - Drying by aspiration and subsequently absorbent papers points (Dentsply

Maillefer).

5- Filling using modified single cone technique (cone .06 caliber used

Subsequent to the Wave One).

6 - After cutting filling with heated pluggers, the acid etch process was carried

out on the dentin walls of the coronary access, followed by restoration with light-

cured resin (Dentsply).

Figure 3 – Tooth restoration

All actions related to biosecurity, absolute isolation and other procedures

were employed maintaining the quality and ethics.

TREATMENT PROTOCOL

1- Radiographic Planning

Figure 4 - Illustrated here, we removed as much information regarding the

possible pulp location, canal, as well as their diameters, distances and possible

features of "normality"

Figure 5 - Planning access surgery taking into account the tooth anatomical

features

2 - Access to the root canal

Figure 6 - Beginning of access surgery with a round bur shortly after the point of

election

Figure 7 - trepanation in the pulp chamber with a round bur

Figure 8 - Removal of ceiling with the Endo-Z drill

Figure 9 - Conducting the form of convenience with the Endo-Z drill

3 - Preparation of the Canal Entry and Continuous Compensatory Wear

When concluded the root canal access to teeth without pulp calcification

or atresia of the camera, after the use of spherical and Endo Z drills (Figures 9,

8:09) and abundant irrigation with 2.5% sodium hypochlorite, with the removal

of the coronary pulp with short (if living pulps) and new irrigation, one can view

the entries. Thus, a rotary tool with a wide variation of taper is used, as the

suggestion the ProTaper SX (Figure 10). This motor driven instrument has an

extremely fine tip that penetrates into the root canal using gentle apical

pressure and withdrawal, as it has a high taper, quickly extends the duct inlet,

without, however, promoting variations in the anatomical profile, i.e maintains

the natural course of the duct with a smooth extension.

Figure 10 - Preparation of the canal entry with the SX Protaper

Now, with well-marked conduct, the Triple Gattes is intriduced, a tool with

variations between the gauges Gattes Glidden 1 to 3, or even their own Gates

and after its use, we resumed SX (Figure 11). This procedure will soften

diameters prepared by integrating them to the anatomical root canal.

Figure 11 - Using the Triple Gattes and ProTaper SX

At this time, one can observe whether we returned or not to increase

coronary compensatory wear with Endo Z for better access to the root canal or

not. The consequence of this action will allow rectification of the cervical

curvature, reducing pressure to instruments that will be used during root canal

preparation.

Figure 12 - Final result of the preparation of the canal entry / continuous wear

compensation. Note the direct and facilitated file access to the canal entry

Figure 13 - Direct view of the canal entry

4 – Suggestion of a new endodontic Protocol using instruments with high tapers

With the emergence of the instruments of varying taper and unique in the

preparation of canals such as the Wave One, a new reality can be observed.

Unlike instruments taper 02, the preparations are performed gradually, i.e. with

light apical pressure toward the real working length. This movement is not

constant, therefore, the operator should "force it" (light pressure) 1-3 times in

the desired direction, and then irrigate the canal, back with a file 15 and with

turning of ¼ apical pressure back and occlusal pressure pull to remove the

instrument, such a movement aims at breaking down, overtaking and removing

the dentin excised. Thus, it is continued the use of oscillating with the same

periods of stop, where the procedures are repeated until reaching the desired

working length.

Such kinematics clarifies that the preparation is carried out from time to

time, not penetrating at once, but gradually to the working length.

Comparing the preparation with hand instruments or those rotary of taper

of 02, we can see a difference. When the preparation is performed with these

instruments, it is first necessary to decide, establish the working length

precision, and at this point starts the preparation with instruments adapted to

this area and dilates the canal with other instruments of larger caliber to the

desired diameter. However, the preparation is always carried out from this point,

since if this approach is not used very accurately, the operator will perform a

step, by more accentuated wear against the wall curvature of the canal, given

the number pressures applied to the tip the instrument in this ecosystem forces.

It does not apply to instruments with taper 06 or 08 or it is extremely reduced,

and thus the conduit can be prepared in cervical-apical direction from time to

time without major problems given the deep and constant compensatory wear.

Thus, following these principles, one can suggest the following protocol

when using reciprocating tools of variable taper:

1 RX Diagnostic - at this time is possible to obtain the apparent length of the

tooth with the aid of rulers and magnifiers. Thus, we will discount 2mm from this

length and establish our limit of temporary work (LTP);

2 when completed access to the pulp chamber and the preparation of the canal

entry, we go beyond LTP access, and for such, we use the following

instruments: Proglide (rotational)

3-Choose the appropriate instrument and use all the principles of preparation,

irrigation and auxiliary chemical substances indicated to achieve the LTP.

4 Completed the preparation to the LTP, introduces a cone gauge on the

reciprocating instrument used or a cone 30 .06 (single cone technique modified

according to Machado, more detail in the Filling Chapter), applies cone proof

(arrival, observe if it is stuck) and x-ray;

5 Analyzing this new radiography we can observe:

a) the cone is in the ideal location or

b) We should adapt it down or not.

With these tools one can delve more if needed in the canal without performing

step or lose anatomical canal

ATTENTION

ANY RECIPROCATING OR ROTARY INSTRUMENT MUST NEVER BE

USED IN A SINGLE POINT (STOPPED WORKING), ALWAYS MOVING IN

WITHDRAWAL OR PENETRATION.

RESULTS

In total between surgeries, restorations and root canal treatments, more

than 200 procedures were performed, the number of treatments and the

average time can be observed in Table 1.

Table 1 - Quantification of the Amazon Project 2014

Description Quantification

days worked 6 days

Number of treatments per day 8 treatments/day

Total treated molars 54 molars

Average time per patient 1 hour

Analyzing the cases treated, tolerable postoperative period was

shortened by 20%, total absence of pain symptoms in 80%. Some cases of

Endodontics performed in this project can be seen in the following images.

Considering the project and conditions stipulated, the technique and

protocol are perfectly appointed to a protocol of endodontic technique of high

practicality, quality and efficiency.

Cumia Lake

REFERÊNCIAS

1. Blank-Gonçalves LM, Nabeshima CK, Martins GHR, Machado MEL.

Qualitative Analysis of the Removal of the Smear Layer in the Apical Third of

Curved Roots: Conventional Irrigation versus Activation Systems. J Endod.

2011; 9(37):1268-71.

2. Duque-Junior DO, Nabeshima CK, Franco EC, Pavanello KC, Machado MEL.

Sistema Wave One: comparação entre diâmetro do preparo radicular e

respectivo cone de guta-percha. Rev Assoc Paul Cir Dent. 2013; 67(2):150-3.

3. Machado MEL. Endodontia - da biologia à técnica. 1a Edição ed. São Paulo:

Editora Santos; 2007.

4. Machado MEL, Sapia LAB, Cai S, Martins GHR, Nabeshima CK. Comparison

of two Rotary systems in root canal preparation regarding disinfection. J Endod.

2010; 36(7):1238-40.

5. Machado MEL, Shin RCF, Zólio AA, Pallotta RC, Nabeshima CK. Confronto

tra la quantità di sigillante nell’otturazione canalare com l’uso di strumentazione

e tecniche d’otturazione diverse. Il Dent Mod. 2010; 28:50-6.

6. Machado MEL, Nabeshima CK, Leonardo MFP, Cardenas JEV. Análise do

tempo de trabalho da instrumentação recíproca com lima única: WaveOne e

Reciproc. Rev Assoc Paul Cir Dent. 2012; 66(2): 120-4.

7. Machado MEL, Nabeshima CK, Leonardo MFP, Reis FAS, Britto MLB, Cai S.

Influence of reciprocating single-file and rotary instrumentation on bacterial

reduction on infected root canals. Int Endod J. 2013; 46:1083-7.

8. Machado MEL, Nabeshima CK, Leonardo MFP, Machado FPL, MLB Britto,

Cai S. Valutazione dell’effetto meccanico di strumenti singoli con movimento

reciprocante (sistema WaveOne) in canali radicolari contaminati. Il Dent Mod.

2013; 31(9): 110-8.

9. Machado MEL, Nabeshima CK, Martins GHR, Britto MLB. Analysis of apical

fitting of .06 and .02 tapered gutta-percha master cones in root canals shaped

with ProTaper rotary system. RSBO. 2013;10(3):224-7.

10. Nabeshima CK, Martins GHR, Leonardo MFP, Shin RCF, Cai S, Machado

MEL. Comparison of three techniques with regard to bacterial leakage. Braz J

Oral Sci. 2013;12(3):212-5.

11. Nabeshima CK, Caballero-Flores H, Cai S, Aranguren J, Britto MLB, Machado

MEL. Bacterial removal promoted by two single-file systems: Wave One versus

One Shape. J Endod. 2014 [in press].

professormachado@hotmail.com