ASSESSMENT OF THE EFFECT OF ENDODONTIC IRRIGATION SOLUTIONS ON THE ROOT DENTIN STATUS

Size: px

Start display at page:

Download "ASSESSMENT OF THE EFFECT OF ENDODONTIC IRRIGATION SOLUTIONS ON THE ROOT DENTIN STATUS"

Mercy Neal
5 years ago
Views:

1 Odontology ASSESSMENT OF THE EFFECT OF ENDODONTIC IRRIGATION SOLUTIONS ON THE ROOT DENTIN STATUS Raluca Mihaela Ro[ca 1, Simona Stoleriu 2, M\lina Niculi]\ 1, Maria Vataman 3, S. Andrian 3 1. PhD student, Dept. Odontology, Faculty of Dent Med, Gr.T.Popa U.M.Ph. Iasi 2. Assist. Prof. PhD. Dept. Odontology, Faculty of Dent. Med, Gr.T.Popa U.M. Ph. Iasi 3. Prof. PhD. Dept. Odontology, Faculty of Dent. Med, Gr.T.Popa U.M. Ph. Iasi Corresponding author: dr. Sorin Andrian: sorinandrian@yahoo.com Abstract The aim of the present study is to determine the cleaning level o f the root canal system from organic and mineral remnants, as well as the extent of smear layer removal, and its quantification, by SEMevaluation of the root canal surfaces obtained after endodontic irrigation with different solutions. Materials and method. 40 human monoradicular teeth, extracted for orthodontic or periodontal reasons, were selected for the study. The teeth were randomly divided into 4 groups. After creating the access to the endodontic space, endodontic instrumentation followed, by the step back technique, up to the level of the apical structure. Endodontic irrigation made use of 10 ml solution, as follows: saline solution for the teeth of group A, 5.25%NaOCI for group B, BioPure MTAD (Dentsply) preparation for group C, and SmearClear (Sybron Endo, Orange, CA) preparation for group D. The roots were longitudinally sectioned, to obtain the inner aspect of the canal, then subjected to SEM analyses. For the reference zones, the amount of smear layer was quantified, scores from 1 to 4 being given. Results. When employing a saline solution, 80% of the samples received score 5, for expressing the smear layer removal. The same score was given to other 25% of the samples, for which 5.25% sodium hypochlorite was applied as an irrigant. Numerous samples (90%) for which Smear Clear was employed were included in score 1 category, only10% receiving score 2. Relatively close percent ratios for the samples in which BioPure MTAD had been employed were included in score 2 and 3 categories (45%, respectively 55%) Conclusions. The increasing order of efficiency, regarding the total smear layer removal and dentinary surface with perfectly open tubules for the irrigants under analysis, was saline solution, sodium hypochlorite, BioPure MTAD and SmearClear. Keywords: sodium hypochlorite, BioPure MTAD, SmearClear, smear layer, SEM INTRODUCTION Cleaning and shaping of the root canal system represents an intermediary stage in the en dodontic treatment, the accomplishment of which decisively influences its success. Elimination of the organic debris is especially important, once known that they may decompose, while the microorganisms may find in the canal the substrate favourizing their proliferation. Several studies demonstrated that instrumentation alone cannot satisfactorily disinfect the radicular canal system (SCR), with either steel (1) or nickeltitanium instruments (2). During instrumentation, the endodontic files release and dislocate the materials present inside the canals, remove the dentin from its walls, the whole content being eliminated by means of an irrigant. The irrigant or the ideal combination of substances should remove the big organic debris, wet the canal walls, destroy the bacteria, dissolve the necrotic tissue, lubricate the canal walls and open the dentinary tubules through removal of the remanent dentinary detritus, thus preparing the surface for an as good as possible adhesion of the sealers to the dentinary surfaces, for disinfecting and clearing the zones inaccesible to endodontic treatments, without irritating the periapical tissues (3). Considering the anatomical complexity and in spite of the minuteness of the instrumental manoevres, of canalary wall host irregularities and of the existence of certain areas that cannot be reached by instruments, chemical agents should be applied for tissular removal. SEM studies demonstrated that 70% of the tissular debris remain, if their preparation involves no irrigation (4). Along the years, various formulae, in various combinations of substances with various concentrations, were employed as irrigation solutions: saline solution, hydrogen peroxide, various anaesthetic solutions, 5.25% sodium 24 volume 15 issue 1 January / March 11 pp 2430

2 ASSESSMENT OF THE EFFECT OF ENDODONTIC IRRIGATION SOLUTIONS ON THE ROOT DENTIN STATUS hypoclorite, quaternary ammonium compounds, 0.2% chlorhexidine, 50% citric acid, EDTA, MTAD, calcium hydroxide, oxidative potential water, RCPrep, Glyde, etc. The aim of the present study is to appreciate the SCR cleaning level of organic and mineral debris, as well as the extent of smear layer removal, and its quantification by SEMevaluation of the root canal surfaces obtained after endodontic irrigation with different solutions. MATERIALS AND METHOD 40 human monoradicular teeth, freshly extracted from either periodontal or orthodontic reasons, were selected, with straight roots and canals and no radiovisible anatomical aberrations and definite apical constrictions, (class I Vertucci canals). The teeth were randomly divided into 4 groups. For each of them, coronary access was performed, through preparation of a typical access cavity, followed by endodontic instrumentation by the step back technique, up to the level of the apical structure, previously identified by measuring the working length (LI). Endodontic irrigation made use of 10 ml solution, as follows: saline solution for the teeth of group A, 5.25% NaOCI for group B, BioPure MTAD (Dentsply) preparation for group C, and SmearClear (Sybron Endo, Orange, CA) preparation for group D. The irrigant was released in the canal by means of a hypodermic syringe and 25 no. needles, with longitudinally sectioned point. The needle point was placed 1 mm up of LI, on condition of its free movement in the canal, thus permitting the irrigant to reflow towards the coronary area and its reaching the previously prepared sturcture, concomitantly with preventing its extrusion in the periapical tissues. When instrumentation is over, final irrigation is made in each group, with a corresponding irrigant (5 ml for 10 sec). In a subsequent stage, the canals were dried with paper cones (VDW, GmbH, Germany). By means of diamond fissure burrs (no. 15 L, Pfingst & Company, Inc, SUA) and a water/air cooling system, the teeth were sectioned at the level of enamelcement junction, the canals being subsequently sealed here with a temporary material (Citodur, DoriDent). The roots were longitudinally sectioned in the vicinity of the canal through 2, mezial and distal, ditches, by means of a diamond disc (Gebr. Brasseler GmbH&Co, Germany), under continuous cooling, after which they were longitudinally cut, by only one strong blow, so that the inner aspect of the canal was obtained. The samples were prefixed in glutaraldehyde for 48 h, then rinsed in a buffer solution and dessicated with cu % acetone for 12 h. The samples were fixed with selfpolymerizable acrylate, on metallic and metalized supports, through catodic pulverization with silver, in a 100 militorres vacuum and 6 volts tension, for 3 min and 30 sec. Together with the metallic supports, the samples were introduced in the column of the microscope (Tesla 3, Czech Rep.), under a 15 kw tension. The status of the parietal dentine surface obtained with each irrigant type could be observed, after which the amount of smear layer was quantified on reference zones, the following scores being given: 1. open dentinary tubules, smear layer absent. 2. low amount of smear layer, a few open dentinary tubules. 3. homogeneous smear layer covering the canal walls and only a few open tubules. 4. canal walls covered by a wholly homogeneous smear layer, no open dentinary tubules. 5. high amount of nonhomogeneous smear layer, covering completely the walls of the canal. For each section, the highest value granted to the presence of the smear layer resulting from the examination of 3 reference zones from the coronary, mean and apical radicular third, was selected as a final score. RESULTS With reference to the level of SCR cleaning of different organic and mineral debris and to the International Journal of Medical Dentistry 25

$Raluca Mihaela Ro[ca, Simona Stoleriu, M\lina Niculi]\, Maria Vataman, S.$ abundant amounts of organic and mineral rests occurred.

The mineral agglomerations are either spherical or stellated, occurring either free or adhering to the canal walls.

Some covered, yet identifiable dentinary tubules may be observed in the background (score 5). In the samples from group B, no big mineral or organic residues could be observed.

The dentinary surface was covered by an apparently compact layer. On certain sections,a homogeneous smear layer, with no open dentinary tubules was observed (score 4) (Fig. 2).

3 Raluca Mihaela Ro[ca, Simona Stoleriu, M\lina Niculi]\, Maria Vataman, S. Andrian extent of smear layer removal, it was observed that, in the samples in which saline solution was employed as an irrigant, the pulp tissue was absent inside the canals, while abundant amounts of organic and mineral rests occurred. On a transversal canal section close to the apical zone, organic rests in fibrous form, with spider web or network aspect, may be observed (Fig. 1). The mineral agglomerations are either spherical or stellated, occurring either free or adhering to the canal walls. One may notice the existence of a rich smear layer entering the dentinary tubules, blocking them at the surface or sometimes, even inside them. Some covered, yet identifiable dentinary tubules may be observed in the background (score 5). In the samples from group B, no big mineral or organic residues could be observed. The surfaces thus obtained showed numerous irregularites, occurring as folds, frequently profound, with a caterpillar trace aspect. The dentinary surface was covered by an apparently compact layer. On certain sections,a homogeneous smear layer, with no open dentinary tubules was observed (score 4) (Fig. 2). In other zones, the smear layer occurred only in low amounts, as islands (Fig. 3) containing some open dentinary tubules (score 3) (Fig. 4). Figure 3. Aspect of root canal dentin after irrigation with NaOCl (score 4) (SEM X 500) Figure 1. Aspect of root canal dentin after irrigation with a saline solution (SEM X 50) Figure 4. Aspect of root canal dentin after irrigation with NaOCl (SEM X 1000) Figure 2. Aspect of root canal dentin after irrigation with NaOCl (score 4) (SEM X 1000) Figure 5. Aspect of root canal dentin after irrigation with MTAD (score 2) (SEM X 500) 26 volume 15 issue 1 January / March 11 pp 2430

ASSESSMENT OF THE EFFECT OF ENDODONTIC IRRIGATION SOLUTIONS ON THE ROOT DENTIN STATUS In the samples from group C, dentin generally showed a clean aspect, with some wavy surfaces created by

A detailed aspect (Fig 6) also evidences a very reduced amount of smearlayer, blocking some other dentinary tubules (score 2 given to the presence of the smear layer).

Most of the dentinary tubules were completely open, highly visible and free of any material, the smear layer being totally absent (value 1) (Fig. 8).

4 ASSESSMENT OF THE EFFECT OF ENDODONTIC IRRIGATION SOLUTIONS ON THE ROOT DENTIN STATUS In the samples from group C, dentin generally showed a clean aspect, with some wavy surfaces created by instrumentation, especially in the coronary third (Fig 5). A detailed aspect (Fig 6) also evidences a very reduced amount of smearlayer, blocking some other dentinary tubules (score 2 given to the presence of the smear layer). In group D, the general aspect of root canal dentine was regular and clear, without any smear layer, at almost all preparation levels (Fig. 7). Most of the dentinary tubules were completely open, highly visible and free of any material, the smear layer being totally absent (value 1) (Fig. 8). The values of the extent of residues and smearlayer removal in the 4 groups under investigation are listed in table I. Table I. Scores for the smear layer aspect when employing various endodontic irrigants Number of samples SCORE Group Group Group C Group D A B (BioPure (SmearClear) (Saline (NaOCl MTAD) solution) 5.25%) Figure 6. Aspect of root canal dentin after irrigation with MTAD (SEM X 1000) Total number of samples Figure 7. Aspect of root canal dentin after irrigation with SmearClear (score 1) (SEM X 500) When using a saline solution, 80% of the samples received score 5, from the point of view of smear layer removal, which is also the case of 25% of the samples in which 5.25% sodium hypochlorite was used as an irrigant. Most of the samples for which Smear Clear (90%) had been used were included in the category with score 1, only10% of them receiving score 2. Relatively close percent values from the samples treated with BioPure MTAD were recorded in score 2 and 3 categories (45%, respectively 55%) (graph 1). Figure 8. Aspect of root canal dentin after irrigation with SmearClear (SEM X 1000) International Journal of Medical Dentistry 27

$Raluca Mihaela Ro[ca, Simona Stoleriu, M\lina Niculi]\, Maria Vataman, S. Andrian DISCUSSION Graph 1.$

5 Raluca Mihaela Ro[ca, Simona Stoleriu, M\lina Niculi]\, Maria Vataman, S. Andrian DISCUSSION Graph 1. Distribution of scores in the 4 experimental groups Generally speaking, endodontic irrigation acts in essentially two ways, namely: physical action, related to the amount and volume of solution released in the radicular canal, and chemical action, related to the quality of solution. Irrigation should facilitate cleaning and removal of all SCR debris, through its mechanical washing action. Irrigation avoids sedimentation of the dentinary mud (smearlayer) and causes suspending of both organic rests and of the dentin layers detached by the instruments. Removal of smear layer is beneficial, as this layer, covering the dentinary surface, might contain necrotic tissue and bacterial rests, while its presence might prevent drugs penetration into the dentinary tubules. More than that, an adequate surface, permitting an intimate contact and adhesion inside the root canal system should be created. Sodium hypochlorite in various concentrations has been used as a canal antiseptic for several decades, due to its efficiency against difficulttoeradicate microorganisms, such as: Enterococcus, Actynomices and Candida. It dissolves the endocanalary organic material, having a minimal action upon both dentine and remanent dentinary detritus; this explains the recommendation for its uasge in association with some demineralizing agents, for increasing its capacity of cleaning the difficulttoinstrumentate zones, such as dentinary tubules and lateral canals (5). Some studies demonstrated that hypochlorite may remove more than 70% of the organic components present in dentine and more than 50% of the pulpar ones (6). The investigations of Baumgartner and Mader (7) assessed that NaOCI, in concentrations between 1.5 : % and 5.25%, is extremely efficient in removing the vital pulpar tissue from the root canal dentin walls, even the noninstrumented ones. The efficiency of NaOCI in this dissolving action is generally accepted nowadays, being influenced by the structural integrity of the compounds of the conjunctive tissue from the pulpar rests. In the present study, the action of sodium hypochlorite gave better results in the removal of the smear layer, comparatively with the saline solution, as actually acknowledged in other studies, too (8). Out of some new bioinstrumentation strategies here applied, mention should be made of the use of canal irrigants and of some antibiotic solutions, such as: erythromycin, chloramphenicol, tetracyclin and vancomicin. The BioPure MTAD (Dentsply/Tulsa, Tulsa, OK) preparation contains doxycyclin, citric acid and a surface tensioactive surfactant. In vitro experiments showed that MTAD has some potential for smear layer removal (9,10), being demonstrated that MTAD is an efficient solution for smear layer removal, without significantly modifying the structure of dentinary tubules, when the canals are irrigated with sodium hypochlorite, followed by MTAD (11). Some studies showed that the MTAD action was considerably more efficient upon the smear layer, comparatively with sodium hypochlorite (12), which is actually the conclusion of the present investigation, as well. Association of BioPure with EDTA led to the obtaining of an area of demineralized colagenic matrix in the eroded dentine, as well as around the dentinary tubules, BioPure being seen, from this perspective, as more aggressive than EDTA. The citric acid contained in the product acts upon the smear layer with both its quantity and homogeneity, having the capacity of forming zones with partially closed tubules, and other with open canalicules. However, the present study confirmed the maintenance of smear layer zones, which partially or totally block the dentinary canalicules. 28 volume 15 issue 1 January / March 11 pp 2430

6 ASSESSMENT OF THE EFFECT OF ENDODONTIC IRRIGATION SOLUTIONS ON THE ROOT DENTIN STATUS The SmearClear (Sybron Endo, Orange, CA) product is a combination of several surfactants and a 17% EDTA solution. The surfactants reduce surface tension and increase the capacity of endocanalary cleaning of some solutions (EDTA). The main action involves removal of the remanent dentinary detritus and opening of the dentinary tubes, as confirmed here by the level of surface cleaning. EDTA appears as a very efficient chelating agent which solubilizes calcium and dentin (13). The optimum ph for EDTA demineralization on dentin should range between 5 and 6 (14). It was demonstrated that EDTA increases permeability in the dentinary canalicules, in the accesory canals and in the apical foramen. EDTA eliminates the smear layer deposits remaining after instrumentation of the canal walls (15). Paterson(16) made the observation that this substance has quite a long action time, its influence upon dentin being manifested long after radicular obturation, if no correct washings had been made. Selection of an adequate irrigation solution has a decisive influence upon the efficiency and success of the endodontic treatment. The smear layer, with a mean thickness of 12 µm, is attached to the dentinary canalicules along 40 nm; once known that these accessory canals have a longer diameter, the material compacted in these canals may occur in high amounts during conventional canal preparation. As an organolytic substance, sodium hypochlorite has no favourable action upon the mineral fraction of root canal dentin, so that irrigation should begin with chelating solutions. CONCLUSIONS 1. The saline solution employed as an irrigation solution was seen as inefficient in removing both organic and mineral debris and smear layer from the canal walls. 2. NaOCI (5.25%) was efficient in the total disolution of organic residues from the inner part of SCR walls, but had no action on the amount and structure of the smear layer formed after endodontic instrumentation. 3. Application of BioPure MTAD (Dentsply/ Tulsa, Tulsa, OK) was actively working upon the smear layer, which it partially removed, remaining only in some obliterated dentinary tubules. 4. The only viable method for total smear layer removal and for obtaining a dentinary surface with perfectly open tubules is based on the use of the SmearClear (Sybron Endo, Orange, CA) preparation. 5. Smear layer removal during endodontic irrigation plays a key role in this stage, influencing the realization of an optimum apical sealing during root canal filling. References 1. Bystrom A, Sundquist G. Bacteriologic evaluation of the efficacy of mecanical root canal instrumentation in endodontic therapy. Scan J Dent Res 1981; 89: Dalton BC, Orstavik D, Phillips C, Pettiette M, Trope M. Bacterial reduction with nickel titanium rotary instrumentation. J Endod 1998; 24: Hulsman M, Heckendorf M, Lennon A. Chelating agents in root canal treatment: mode of action and indications for their use. Int Endod J 03; 36: Carvalho A S, Camargo C H R, Valera MC, Camargo SE. Smear layer removal by auxiliary chemical substances in biomechanical preparation: a scanning electron microscope study. J Endod 08;11: Bystrom A, Sundqvist G. The antibacterial action of sodium hypochlorit and EDTA în 60 cases of endodontic therapy. Int Endod J 1985; 18: Benz RI, Torabinejad M, Pouresmail M. Quantitative analysis of the solubilizing action of MTAD, sodium hypochlorite, and EDTA on bovine pulp and dentin. J Endod 03; 29 : Baumgartner JC, Mader C. A S.E.M. evaluation of four root canal irigation regimens. J. Endod. 08; 13: O Hara PC. Antibacterial effect of various endodontic irrigants and medicaments on anaerobes. J.of Endod 09; 18: Shabahang S, Pouresmail M, Torabinejad M. In vitro antimicrobial efficacy of MTAD and sodium hipochlorite. J Endod 03; 29: Torabinejad M, Cho Y, Khademi AA, Backland LK. The effect of various concentrations of sodium hipochlorite on the ability of MTAD to remove the smearlayer. J Endod 03; 23: International Journal of Medical Dentistry 29

7 Raluca Mihaela Ro[ca, Simona Stoleriu, M\lina Niculi]\, Maria Vataman, S. Andrian 12. Mancini M, Armelin E, Casaqlia A, Cerroni L, Ciaconi L. A Comparative Study of Smear Layer Removal and Erosion in Apical Intraradicular Dentine With Three Irrigating Solutions: A Scanning Electron Microscopy Evaluation. J of Endod 09; 35 : Tay FR, Pashley DH, Loushine RJ, Doyle MD, Gillespie WT, Weller RN, King NM Ultrastructure of Smear LayerCovered Intraradicular Dentin After Irrigation with BioPure MTAD. J of Endod 06; 32: Valdrighi L. The demineralising efficiency of E.D.T.A. solutions on dentin. Oral.Surg. 08; 52: Ando F. A study of chemical preparation in endodontic therapy. The effect of E.D.T.A on powdered dentin and dentinal walls. J.Dent.Sci. 1997; 23: Patterson J. In vivo and in vitro studies of the effect of E.D.T.A. on human dentine and its endodntic implications. Oral.Surg. 08; 18: volume 15 issue 1 January / March 11 pp 2430

Smear layer removal evaluation of different protocol of Bio Race file and XPendo Finisher file in corporation with EDTA 17% and NaOCl

Smear layer removal evaluation of different protocol of Bio Race file and XPendo Finisher file in corporation with EDTA 17% and NaOCl Journal section: Operative Dentistry and Endodontics Publication Types: Research doi:10.4317/jced.54179 http://dx.doi.org/10.4317/jced.54179 of different protocol of Bio Race file and XPendo Finisher file