The effect of giving NaOCL 2.5% and H2O2% solution on the initial setting Mineral Trioxide Aggregate (MTA)

Today, Mineral Trioxide Aggregate (MTA) is one of the most commonly-used materials to overcome problems in dental pulp as well as periodontal tissue. This substance received its permission from the American Food and Drug Administration (FDA) in 1998 and has been patented as a Portland type I.ASTM C150 cement-base material. However, MTA still has its flaws, such as: its granule form, requirement for moist condition, mass losing during hydration (high solubility), and particularly its time-consuming setting duration (45’-165’). Some researches attempt the usage of regular accelerator together with Portland cement, yet there’s still no certainty of the best concentration that can be used to gain optimal result. This research conducted a time test of the initial setting of MTA that was mixed with the strongoxidation antimicrobial solutions, they are NaOCl 2.5% dan H2O2 3%. The instrument used was the Gillmore needle. Data analysis used one-way ANOVA and Mann Whitney significance test (p<0,05). The result of the research showed that the mixing of NaOCl 2.5% with MTA the initial setting was ± 11 minutes and the mixing of NaOCl 2.5% with MTA the initial setting was ± 5 minute, it compared with the initial setting of original MTA which was the initial setting ± 50 minutes.


INTRODUCTION
The development in dentistry, Endodontic area, is now focused on some techniques and materials that are able to optimize teeth tissues repair and their surroundings.Various materials have been tested in order to get the best result in overcoming diseases/disorders in teeth pulp or in periodontium tissue.
][3] Deus et al. 4 and Min et al. 5 that studied human cells' response on MTA concluded that this material was non toxic.The same thing happened to tissue reaction which was seen in a 12 week in vitro and in vivo observations on animal.][8] There are some problems in MTA use in clinics, the granule consistencies.This matter gives difficulty in its mixing and situating in cavity.The ossification time is rather long, about 45-165 minutes 1,9 , and there was also mass loss during ossification period.There was 1% loss mass, in the research held by Bodanezzi 10 , which took time 24-672 hours. 10In its ossification, this material needs damp atmosphere, so it is known as a material with difficult handling. 11This situation is an obstacle found in clinics when they want to hold action and restoration in one time visit.
There are a lot of researchers that try to find out some solutions on MTA: the ossification period, the compressive strength, and the amenity during mixing.By adding an addition material (accelerator), Kogan et al. 1 held a research on some addition materials, such as chlorhexidin gel, NaOCl 3% (ChlorCid V, Ultradent) gel, K-Y gel, saline and lidokain HCI which are regarded as antimicrobacterial.The research proved that only NaOCl 3% and K-Y gel which showed fast time setting, it was 20 minutes. 1 Natrium Hypochlorite (NaOCl) is a bactericid and virusid material.In endodontic area, this material is commonly used in concentration between 1-5%.This material possesses alkali pH (11-14), and it is also known as an effective irrigation material since it is able to dissolve protein and microorganism, and also has low surface tension so that this solution can penetrate to narrow root channel. 14,15In 1-5% concentration, NaOCl can be said as biocompatible. 14,15Two and half percent NaOCl is widely used in dental clinics because of its odor which is not as sharp as other materials with higher concentration, but it gives the same bactericid effect as the 5% concentration. 16In this research, the use of 2.5% NaOCl solution is based on the MTA hydration nature that needs sufficient amount of water to start materials mixing.NaOCl solution is a strong oxidator 15,16 , so that it is hoped to be an initiator in a chemical reaction with accelerating MTA initial setting effect.
There is another material in dentistry that also has antimicrobacterial nature, that is hydrogen peroxide.Hydrogen peroxide (3%) is quite environment safe due to its easily decomposed into water (H 2 O) and oxygen (O 2) ). 17,18H 2 O 2 solution with 3% concentration (3% H 2 O 2 , 97% H 2 O 2 is commonly used in medical area as irrigant/ wound cleaner, and is a strong oxidator as well, in which in alkali atmospehere it can quickly react and can be decomposed into water and oxygen, and this all is needed for setting. MTA and its mixing process need water (H 2 O) for hydration, and oxygen to help the connection of cemen particles.Both materials (NaOCl and H 2 O 2 ) contain dissolved concentration in water.They are strong oxidators, which are hoped to accelerate setting time.
The determination of solution concentration is mainly focused on its use in clinics, so that it can be easily got when it is needed.Comparing the addition of two solutions H 2 O 2 3% and NaOCl 2.5% to MTA, to the initial setting speed.Consequently, according to the ability to initiate, it is estimated that the hydrogen peroxide 3% solution shows faster time than natrium hypochlorite 2.5%.

MATERIALS AND METHODS
MTA sample was made in 3 groups, In group 1 (control), MTA was mixed with steril water (bottled) that is manufactured by a factory.Group 2 the sample was made by mixing 1 gram of MTA powder with 0.30 ml NaOCl 2.5% solution, in group 3 it was made by mixing MTA with 0.30 ml H 2 O 2 3% solution.Each mixture was divided into 15 rings, size Ø4 mm, height 3 mm.Five rings were given for each group and time-based indentation measuring was held.Untested samples had to be covered by wet kassa or placed in an incubator with 95% in dampness and 37% in temperature.
Sample testing setting time measurement was conducted by using Gillmore equipment with the indenter needle with its Ø2,12 mm flat tip and a pendulum, mass 113 gram.The procedure was by placing the indenter needle on the sample for five seconds.The first sample testing was conducted during the beginning of the setting with interval 1-5 minutes.The initial setting was defined as the time length until the sample ossificated in the ring in which the indenter needle could not mark the samples' surfaces and it was done in three spots.The writer took note of the time of each sample.

RESULTS
The setting time was treated by mixing MTA with packed liquid (H 2 O steril), NaOCl 2.5% solution and H 2 O 2 3% solution.The mixture existed in each of those three groups which consisted of 9 samples.The time calculation using Gillmore needle was by noticing indentation existence.
Based on the research result, statistical analysis was conducted and noticed the difference of meaning with the result, as seen in Table 1.
Time average result showed that control needed initial setting average 50.22±0.44minutes which was the longest time to reach the initial setting compared to MTA + NaOCl 2.5% that needed setting time 11.11±0.33minutes, and the fastest time for initial setting was the mixture between MTA + H 2 O 2 3% that needed 5.11±0.60minutes, as seen in Figure 1.
The result was the meaning difference between control initial setting with MTA + NaOCl.The result of different meaning also occured in control initial setting with MTA+H 2 O 2 and in initial setting between MTA+NaOCl with MTA+H MTA+NaOCl with MTA+H 2 O 2 as well.
Based on the result, the null hypothesis which meant the NaOCl 2.5% solution could NaOCl 2.5% solution could indeed the MTA initial setting time.Also, the H 2 O 2 3% solution could also accelerate the MTA initial setting time and H 2 O 2 3% solution and it showed faster initial setting than NaOCl 2.5% solution.

DISCUSSION
The Mineral Trioxide Aggregate (MTA) powder was used in this research which was a packed material that has been used and has an official confession from FDA (Food and Drug Association).Choosing NaOCl 2.5% and H 2 O 2. 3% solution was because both of this solution is antimicrobacterial liquid that is commonly used in medical area, and also it is quite easy to get them with friendly price.Chemically, the solution is strong oxidator and it is hoped to be hydration reaction initiator so that it can accelerate MTA setting time.Consequently, initial setting result can be a consideration in clinics when they are going to use this material to shorten visiting time.
The start time of Gillmore needle indentation measuring in MTA setting test with the addition of NaOCl 2.5% was determined by the result of the previous study which got 12 minutes in score.Since the first sample showed faster MTA setting time, the observation time was shortened to 1 minute interval, started from the 9 th minute to the 12 th minute.Deciding the intervals between 1 minute or 5 minutes was based on the research conducted by Wiltbank et.al.During the concoction, mixture consistency was better and the mixture of powder and liquid seemed faster compared to the mixture of MTA and manufactured steril liquid so that the placement in mold was easy.
As in the test of MTA with NaOCl 2.5% solution, the addition of H 2 O 2 3% solution to MTA powder also created the setting time reduction into 5 minutes, so that the Gillmore needle indentation observation was conducted every minute, started in minute 3 to minute 7. The mixture of the solution with MTA powder produced  .Next, these free radical electrons will attach to the condensed monomer and formed oxygen chain to create polymerization.When homopolymers or with other heteropolymers are formed because of the reactive radical ions, the process of polymerization will happen quickly.
As explained before, O n was a very reactive free radical electron and it initiated condensation (tie release of H-OH from Sillica or Alum hydrate).
That was what happened in NaOCl 2.5% addition to MTA powder.NaOCl will release its radical ion (O n ) to initiate hydration process, while Na or CI ion (composed) can also attach to polymer as balance ions.Consequently, defining the initial setting time of adding NaOCl 2.5% to MTA is faster than in control.
There is an explanation on why H 2 O 2 3% solution gives setting time with faster MTA than NaOCl 2.5% solution in MTA.The answer is, the H 2 O 2 mobility is better than NaOCl.H 2 O 2 solution which in contact with MTA powder will soon decompose into H 2 O (water) and radical ion (O n ).With the existence of water, the capability of O n to initiate to all over the monomer areas is better, so that condensation process will run faster.
Cement setting time (MTA) is also influenced by environment temperature.Higher environment temperature will make setting time runs faster, in other words, it influences condensation process or H 2 O 2 release and polymer formation. 21In this research, measurement was conducted in room g g g g