SciELO - Scientific Electronic Library Online

vol.26 número2Antimicrobial activity of fractions and subfractions of elaeagia utilis against microorganisms of importance in dental cariesOxidative stress assessed in saliva from patients whit acute myocardial infarction: A preliminary study índice de autoresíndice de assuntospesquisa de artigos
Home Pagelista alfabética de periódicos  

Serviços Personalizados




  • Não possue artigos citadosCitado por SciELO

Links relacionados

  • Não possue artigos similaresSimilares em SciELO


Acta Odontológica Latinoamericana

versão On-line ISSN 1852-4834

Acta odontol. latinoam. vol.26 no.2 Buenos Aires out. 2013



Influence of irrigation and obturation techniques on artificial lateral root canal filling capacity


Emmanuel J. Silva1, Daniel R. Herrera2, Eduardo J. Souza-Júnior2, João M. Teixeira3

1 Health Sciences Center, Grande Rio University (UNIGRANRIO), Brazil.
2 School of Dentistry of Piracicaba, State University of Campinas (FOP-UNICAMP),Brazil.
3 Rio de Janeiro State University, Brazil.

CORRESPONDENCE Dr.Emmanuel JNL Silva Rua Herotides de Oliveira 61/902, Icarai, Niteroi, RJ - Brazil e-mail:


The aim of this study was to evaluate the influence of two different irrigation protocols on artificial lateral root canal filling capacity using different obturation techniques. Sixty single-root human teeth were used. Two artificial lateral canals were created in the apical third. Root canals were instrumented up to a 45 K-file to the working length. Before each file, root canals were irrigated either with 2 mL of 2.5% NaOCl or 2% chlorhexidine gel with further irrigation with saline solution and 3 mL of 17% EDTA. Specimens were randomly divided into three groups according to the obturation technique: (1) lateral compaction technique; (2) Tagger hybrid technique; and (3) thermoplasticized technique using BeeFill 2 in 1. All groups used AH Plus as the root canal sealer. The specimens were decalcified and cleared in methyl salicylate. The total length of lateral canals was observed under X30 magnification with a stereomicroscope and measured on the buccal and lingual root surfaces using Leica IM50 software. The data were submitted to ANOVA and Tukey test (p<0.05). Among the obturation techniques, BeeFill 2 in 1 showed deeper penetration into all lateral canals than the lateral compaction or Tagger hybrid techniques (p<0.05). The lateral compaction group showed the worst results (p<0.05). Irrigants did not affect the outcome; there was no difference between NaOCl and chlorhexidine when the same obturation technique was used (p>0.05). Regardless of the irrigant used during endodontic procedures, the thermoplasticized techniques showed higher penetration behavior for filling artificial lateral canals than the lateral compaction technique.

Key words: Endodontics; Therapeutic irrigations; Root canal obturation; Sodium hypochlorite; Chlorhexidine.

Influéncia dos irrigantes e das técnicas obturadoras na capacidade de preenchimento de canais laterais artificiais


O objetivo do presente estudo foi avaliar a influencia de dois diferentes protocolos de irrigacao na capacidade de penetracao de canais artificiais, utilizando diferente tecnicas de obturacao. Sessenta dentes humanos unirradiculares foram utilizados. Dois canais laterais artificiais foram confeccionados no terco apical do dente. Os canais foram instrumentados ate uma lima K 45 no comprimento de trabalho. Antes do uso de cada lima, os canais radiculares foram irrigados com 2 mL de NaOCl 2.5% ou com Clorexidina gel 2% seguido de solucao salina. Ambos os grupos receberam no final da instrumentacao 3 mL de EDTA 17%. Os especimes foram randomicamente separados em 3 subgrupos de acordo com a tecnica de obturacao utilizada: (1) tecnica de compactacao lateral; (2) tecnica hibrida de Tagger; e (3) tecnica termoplastica utilizando o BeeFill 2 em 1. Em todos os grupos o cimento utilizado foi o AH Plus. Depois, os elementos foram diafanizados utilizando metil salicilato. As extensoes de pe - netracao dos cimentos nos canais laterais foram realizadas utilizando estereomicroscopio (X30). Os dados de cada grupo foram analizados utilizando ANOVA e o teste de Tukey (p<0.05). Dentre as tecnicas de obturacao, a tecnica termoplastica utilizando o BeeFill 2 em 1 mostrou a maior penetracao em canais laterais (p<0.05). A tecnica de compactacao lateral apresentou os piores resultados dentes os grupos testados (p<0.05). Os irrigantes nao afetaram a penetracao dos canais laterais; nao foram observados diferencas entre NaOCl e clorexidina, quando a mesma tecnica de obturacao foi utilizada (p>0.05). Pode-se concluir que independente da substancia quimica auxiliar utilizada, as tecnicas termoplasticas de obturacao demonstraram maior penetracao de canais laterais do que a tecnica de compactacao lateral.

Palavras-Chave: Endodontia; Irrigacao; Obturacao do canais; Hipoclorito de sodio; Clorexidina.



It has been demonstrated that the quality of root canal obturation is important to the successful outcome of endodontic therapy1,2. The anatomy of the root canal system is composed of various irregularities, creating challenges for a proper seal during obturation3. Root canal ramifications, such as lateral, secondary and accessory canals can establish connection between the main root canal and periodontal ligament, as well as the apical foramen4. Several authors5-7 have reported that localized periodontal problems might be associated with necrotic and infected root canal ramifications, highlighting the importance of the capacity of the root canal sealers to flow into these irregularities.
Many techniques and materials have been used to fill anatomically complex root canal spaces, such as isthmuses and lateral canals. Gutta-percha is the most widely used and accepted root canal filling material. It seems to be the least toxic, least tissueirritating, and least allergenic filling material available8. A variety of thermoplasticized gutta-percha techniques have been introduced recently and a number of investigations have evaluated the apical seal obtained by using them9-11.
To achieve the best adaptation of filling material, it is necessary to clean the dentin wall of smear layer and debris. Root canal irrigants are used during chemomechanical procedures not only as antimicrobial agents but also to lubricate the dentinal walls, flush out debris and dissolve organic and inorganic components of the smear layer to clean dentine surface12,13. However, little information is available regarding the effect of different irrigants associated to different obturation techniques on lateral canal fillings. Therefore, the goal of this study was to evaluate the influence of two different irrigation protocols on artificial lateral root canal filling capacity using different obturation techniques. The null hypothesis was that there is no influence of 2.5% sodium hypochlorite or 2% chlorhexidine gel on artificial root canal filling capacity.


Sixty recently extracted human maxillary anterior teeth were used for this study. The crowns of the teeth were removed using a low-speed diamond disc under running water and a standard length of 15 mm was achieved for every root. The coronal and middle thirds of the root canals were shaped with size 3 and 2 Gates- Glidden burs (Dentsply Maillefer, Ballaigues, Switzerland). The working length was established by subtracting 1 mm from the measurement determined by placing a size 10 K-file (Dentsply Maillefer) into the root canal until the tip could be seen at the foramen. The apical third was prepared up to a size 45 K-file.
Two artificial lateral canals were prepared in the apical third, perpendicular to the longitudinal axis of the teeth, using 0.15 mm cylindrical drills, which created the perforations. Before each file, root canals were filled with 2 mL of either 2.5% NaOCl or 2% chlorhexidine gel; after each file, root canals were irrigated with saline solution. Then 3 mL of 17% EDTA were used for 3 min to remove the smear layer. Finally the root canals received irrigation with 3 mL of saline solution. The root canals were dried with paper points. The 60 teeth were randomly divided into six equal groups of 10. AH Plus (Dentsply) was used as the root canal sealer in all groups. The sealer was mixed according to the manufacturer´s instructions and applied with a size 40 spiral Lentulo (Dentsply Maillefer), and the root canals were obturated according to the following techniques.
Group 1 (Lateral Compaction Technique): A medium gutta-percha cone (Sure-Endo, Sure Products, Seoul, Korea) was standardized with a #45 point and fitted as a master cone. Lateral compaction was performed using a #30 finger spreader (Dentsply Maillefer) and fine accessory gutta-percha cones. The excess guttapercha was removed with a heated ball burnisher.
Group 2 (Tagger Hybrid Technique): This procedure was similar to that of Group 1. The difference was that after lateral compaction, the mass of gutta-percha was thermomechanically compacted in the coronal and middle thirds of the root canal using a #45 gutta-condensor (Dentsply Maillefer) rotated at 10.000 rpm in a slow-speed handpiece. Finally, the gutta-percha was compacted vertically using heat-carrier pluggers.
Group 3 (Thermoplasticized technique using BeeFill 2 in 1): A medium gutta-percha cone (Dentsply) was standardized with a #45 point and was fitted as a master cone. The BeeFill heat source (VDW, Munich, Germany) was activated and a small preheated plugger was inserted into the root canal to perform the downpack. Vertical compaction was performed using heatcarrier pluggers. The middle and coronal thirds of the root canal were backfilled using BeeFill 2 in 1 device. After filling, all groups of teeth were maintained for 48 h at high humidity and 37oC to allow the sealers to set. The teeth were decalcified in 5% hydrochloric acid for 72 h and cleared in methyl salycilate14. The total length of lateral canals was observed under X30 magnification with a stereomicroscope (Leica MZ 75, Leica, Wetzlar, Germany) and measured on the buccal and lingual root surfaces using Leica IM50 software. These measurements were converted to percentages. The results were recorded, and a multiple- comparison analysis of variance test followed by a Tukey post hoc test were used to compare filling material flow into lateral canals (p<0.05).


Mean values (mm) of gutta-percha penetration into lateral canals are presented in Table 1. Among the obturation techniques, the thermoplasticized technique using BeeFill 2 in 1 showed deeper penetration into all lateral canals than the lateral compaction or Tagger hybrid techniques (p<0.05). The lateral compaction technique showed the worst means among the tested groups (p<0.05). Fig. 1 shows representative samples of all groups. The root canal irrigants did not affect the outcome; there was no statistical difference between NaOCl and chlorhexidine when the same obturation technique was used (p>0.05).

Table 1: Group distribution and mean penetration into lateral canals.

Fig. 1
: Representative sample of lateral canal penetration. (a) Lateral Compaction + NaOCl; (b) Lateral Compaction + Chlorhexidine; (c) Tagger Hybrid Technique + NaOCl; (d) Tagger Hybrid Technique + Chlorhexidine; (e) BeeFill 2 in 1 + NaOCl; and (f) BeeFill 2 in 1 + Chlorhexidine.


Post-treatment apical periodontites is caused by either persistent or secondary intraradicular infection15. Persistent infections are caused by microorganisms that persisted after intracanal procedures of disinfections, especially where instruments did not reach secondary canals and dentinal tubules, and managed to survive in the filled root canal. Secondary infections, in turn, are usually caused by microorganisms introduced in the canal via bleach in asepsis during treatment or via coronal leakage in filled root canals exposed to the oral cavity16.
Ramifications in the main canal, such as lateral canals, have great clinical importance in endodontic therapy, mainly when associated with lateral lesions16. Persistent intraradicular infection caused by bacteria located within dentinal tubules can be responsible for the reappearance of apical periodontitis17. This highlights the importance of achieving proper disinfection of the root canal system for a predictable long-term treatment outcome. Bacteria causing persistent infections are usually located in areas unaffected by instruments and antimicrobial substances, including lateral canals, apical ramifications, and isthmuses18. In this study, to reproduce the conditions observed in clinical practice, simulated lateral canals were created having a diameter of approximately 0.15 mm, which matches the size of lateral canals reported in previous studies4,17,18.
One of the desirable properties of irrigants is smear layer removal. Many authors have demonstrated that canal surfaces without a smear layer permit penetration of filling materials into patent dentinal tubules, increasing the contact surface and improving mechanical retention19. In this study, the teeth irrigated with 5.25% NaOCl or 2% chlorhexidine gel combined with 17% EDTA showed similar results after obturation. Previous studies demonstrated that both irrigants are highly efficient in smear layer removal20,21, and this may have influenced the results.
The thermoplasticized techniques used in this study filled more lateral canals than the lateral compaction technique. This confirms the observations of Buchanan22, who states that the continuous wave of condensation can fill lateral and accessory canals with thermoplasticized gutta-percha and sealers. The literature has also reported that the warm gutta-percha technique promotes better filling quality and results in virtually no gaps, very low amounts of sealer on the root surface, and great er adaptation to dentinal walls, unlike the lateral condensation technique23-25. An interesting finding with high-temperature thermoplasticized gutta-percha obturation was its apical control. It was noted that during use of thermoplastic techniques it is necessary to take into account the accuracy and experience of the operator, since they are capable of promoting great leakage in apical region if not properly used. The null hypothesis of this study - that there is no influence of 2.5% NaOCl or 2% chlorhexidine gel on lateral canal filling capacity - was accepted. In conclusion, regardless of the irrigant used during endodontic procedures, the thermoplasticized techniques showed better results for filling artificial lateral canals than the lateral compaction technique. Although NaOCl is widely used as an irrigant in endodontics, 2% chlorhexidine gel also has been used successfully during endodontic procedures. Based on the results obtained in this study, we can state that artificial root canal filling capacity is not affected by the irrigant selected.


1. Balto K. Root-filled teeth with adequate restorations and root canal treatment have better treatment outcomes. Evid Based Dent 2011;12:72-73.         [ Links ]

2. Williams JV, Williams LR. Is coronal restoration more important than root filling for ultimate endodontic success? Dent Update 2010;37:187-193.         [ Links ]

3. Davis SR, Brayton SM, Goldman M. The morphology of the prepared root canal: a study utilizing injectable silicone. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 1972;34:642-648.         [ Links ]

4. De Deus QD. Frequency, location, and direction of the lateral, secondary, and accessory canals. J Endod 1975;1:361-366.         [ Links ]

5. Ricucci D, Siqueira JF Jr. Fate of the tissue in lateral canals and apical ramifications in response to pathologic conditions and treatment procedures. J Endod 2010;36:1-15.         [ Links ]

6. Barkhordar RN, Stewart GG. The potential of periodontal pocket formation associated with untreated accessory canals. Oral Surg Oral Med Oral Pathol 1999;70:769-772.         [ Links ]

7. Song M, Kim HC, Lee W, Kim E. Analysis of the cause of failure in nonsurgical endodontic treatment by microscopic inspection during endodontic microsurgery. J Endod 2011; 37:1516-1519.         [ Links ]

8. Scotti R, Tiozzo R, Parisi C, Croce MA, Baldissara P. Biocompatibility of various root canal filling materials ex vivo. Int Endod J 2008;41:651-657.         [ Links ]

9. Punia SK, Nadig P, Punia V. An in vitro assessment of apical microleakage in root canals obturated with gutta-flow, resilon, thermafil and lateral condensation: A stereomicroscopic study. J Conserv Dent 2011;14:173-177.         [ Links ]

10. Onay EO, Orucoglu H, Kiremitci A, Korkmaz Y, Berk G. Effect of Er, Cr:YSGG laser irradiation on the apical sealing ability of AH Plus/gutta-percha and Hybrid Root Seal/ Resilon Combinations. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2010;110:657-664.         [ Links ]

11. Ari H, Belli S, Gunes B. Sealing ability of Hybrid Root SEAL (MetaSEAL) in conjunction with different obturation techniques. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2010;109:e113-116.         [ Links ]

12. Jainaen A, Palamara JE, Messer HH. Effect of dentinal tubules and resin-based endodontic sealers on fracture properties of root dentine. Dent Mater 2009;25: e73-81.         [ Links ]

13. Akisue E, Tomita VS, Gavini G, Poli de Figueiredo JA. Effect of the combination of sodium hypochlorite and chlorhexidine on dentinal permeability and scanning electron microscopy precipitate observation. J Endod 2010; 36:847-850.         [ Links ]

14. Zaia AA, Nakagawa R, De Quadros I, Gomes BP, Ferraz CC, Teixeira FB, Souza-Filho FJ. An in vitro evaluation of four materials as barriers to coronal microleakage in rootfilled teeth. Int Endod J 2002;35:729-734.         [ Links ]

15. Ricucci D, Bergenholtz G. Bacterial status in root-filled teeth exposed to the oral environment by loss of restoration and fracture or caries - a histobacteriological study of treated cases. Int Endod J 2003;36:787-802.         [ Links ]

16. Vertucci FJ, Anthony RL. A scanning electron microscopic investigation of accessory foramens in the furcation and pulp chamber floor of molar teeth. Oral Surg Oral Med Oral Pathol 1986;62:319-326.         [ Links ]

17. Vieira AR., Siqueira JF Jr., Ricucci D., Lopes WS. Dentinal tubule infection as the cause of recurrent disease and late endodontic treatment failure: a case report. J Endod 2012; 38:250-254.         [ Links ]

18. Ricucci D, Siqueira JF Jr. Recurrent apical periodontitis and late endodontic treatment failure related to coronal leakage: a case report. J Endod 2011;37:1171-1175.         [ Links ]

19. White RR, Goldman M, Lin PS. The influence of the smeared layer upon dentinal tubule penetration by plastic fillinhg materials. J Endod 1984;10:558-562.         [ Links ]

20. Carvalho AS, Camargo CH, Valera MC, Camargo SE, Mancini MN. Smear layer removal by auxiliary chemical substances in biomechanical preparation: a scanning electron microscope study. J Endod 2008;34:1396-1400.         [ Links ]

21. Ferraz CC, Gomes BP, Zaia AA, Teixeira FB, Souza-Filho FJ. In vitro assessment of the antimicrobial action and the mechanical ability of chlorhexidine gel as an endodontic irrigant. J Endod 2001;27:452-455.         [ Links ]

22. Buchanan LS. The art of endodontics laboratory course manual. Santa Barbara, CA: Dental Education Laboratories, 1994.         [ Links ]

23. DuLac KA, Nielsen CJ, Tomazic TJ, Ferrillo PJ Jr, Hatton JF. Comparison of the obturation of lateral canals by six techniques. J Endod 1999;25:376-380.         [ Links ]

24. Michelotto AL, Moura-Netto C, Araki AT, Akisue E, Moura AA, Sydney GB. In vitro analysis of thermocompaction time and gutta-percha type on quality of main canal and lateral canals filling. Braz Oral Res 2010;24:290-295.         [ Links ]

25. Carvalho-Sousa B, Almeida-Gomes F, Carvalho PR, Maniglia- Ferreira C, Gurgel-Filho ED, Albuquerque DS. Filling lateral canals: evaluation of different filling techniques. Eur J Dent 2010;4:251-256.         [ Links ]

Creative Commons License Todo o conteúdo deste periódico, exceto onde está identificado, está licenciado sob uma Licença Creative Commons