Analysis of the Prognostic Factors That Influence the Outcome of Periapical Surgery, including Biomimetic Membranes for Tissue Regeneration: A Review.

The objective of this study was to analyze the prognostic factors that influence the outcome of periapical surgery. A systematic search of the literature was carried out using PubMed and Scopus databases between January 2000 and December 2023 with no language limitations. The PICO question of the present systematic review was: What prognostic factors may influence the outcome of periapical surgery? The most relevant randomized controlled clinical trials (RCTs), prospective clinical trials, retrospective studies, and meta-analyses (n = 44) were selected from 134 articles. The reviewed literature evidenced that bone-lesion healing could significantly be improved by the absence of deep periodontal pockets (>4 mm), localization in anterior teeth, the absence of pain and/or preoperative symptoms, a size of bone lesion < 5 mm, the use of ultrasound, the correct placement of retrograde filling material, and the use of different biomimetic membranes for guided tissue regeneration (GTR). Some preoperative and intraoperative factors could significantly improve the prognosis of periapical surgery. However, these results were not conclusive, and further high-quality research is required.

Oral pregabalin for postoperative pain relief after third molar extraction: a randomized controlled clinical trial.

OBJECTIVES: The aim of this randomized controlled clinical trial was to evaluate the efficacy and safety of pregabalin administered pre- and postoperatively in patients with pain and swelling due to the surgical removal of impacted lower third molars. MATERIALS AND METHODS: The final study sample comprised 60 volunteers (23 males and 37 females). Group 1 (n = 30) received 75 mg oral pregabalin 1 h before surgery and 1 h after surgery. Group 2 (n = 30) served as a control group and received no pregabalin. Both groups were administered with 650 mg paracetamol every 8 h for 2 days. Postoperative pain intensity and swelling were measured using a visual analog scale (VAS); pain relief experienced was reported using a four-point verbal rating scale (VRS); the rescue medication requirement, adverse effects, and global impression of the medication were also recorded. RESULTS: No significant difference in pain intensity (VAS) was observed between the groups. However, fewer rescue medication tablets were needed by pregabalin-treated patients than by controls (p = 0.021). The frequency and intensity of adverse effects were significantly higher in pregabalin-treated patients (p < 0.001), although no serious adverse events occurred. No significant difference in the degree of swelling was observed in any measurement except that from mandibular angle to lip junction, which showed lesser inflammation in the pregabalin group at 24 h post-surgery (p = 0.011). The global opinion on the medication received was more positive in the pregabalin group (p = 0.042). CONCLUSIONS: The administration of pregabalin reduces the requirement for rescue medication after third molar surgery and results in a more constant pain level, with fewer peaks of pain intensity. CLINICAL RELEVANCE: These findings suggest that pregabalin may be useful to control acute postoperative pain. Adverse effects are known to be reduced at the low pregabalin dose used in our study.

Antimicrobial activity of essential oils and chloroform alone and combinated with cetrimide against Enterococcus faecalis biofilm.

The Enterococcus faecalis bacteria have been identified as the most commonly recovered species from teeth with persistent endodontic infections. The antimicrobial activity of essential oils and chloroform (CHL), alone and in association with various concentrations of cetrimide (CTR), against biofilm of Enterococcus faecalis was investigated. Solutions of CHL, eucalyptus oil (EO) and orange oil (OO) associated with CTR at 0.3%, 0.2%, 0.1%, and 0.05% were used to determine antimicrobial activity by exposing treated bovine dentine blocks to E. faecalis. Biofilms grown in the dentine blocks for 7 days were exposed to solutions for 2 and 5 min. Biofilm reduction between OO and EO at 2 min did not show any significant differences; however, OO had a higher kill percentage of biofilms than did the eucalyptus oil at 5 min (p < 0.01). Combinations with CTR at all concentrations achieved a 100% kill rate at 2 and 5 min. The association of CTR with solvent agents achieved the maximum antimicrobial activity against E. faecalis biofilms in dentine.

Ex vivo microbial leakage after using different final irrigation regimens with chlorhexidine.

OBJECTIVE: To assess the influence of final irrigation protocols with chlorhexidine in the coronal leakage of Enterococcus faecalis in filled root canals. MATERIAL AND METHODS: Seventy single-root canals from extracted teeth were prepared using ProTaper instruments. The irrigation protocol accomplished an alternating irrigation with 5 mL of 2.5% sodium hypochlorite (NaOCI) and 17% EDTA between each file. The teeth were randomly divided into four experimental groups (n=15) according to the final irrigation regimen: group 1, without final irrigation; group 2, irrigation with 10 mL 2.0% chlorhexidine (CHX); group 3, with a final application of EC40™; and group 4, irrigation with the combination (1:1) of 0.2% CHX + 0.1% cetrimide (CTR). All the teeth were mounted in a two-chamber apparatus and the coronal access was exposed to E. faecalis. The presence of turbidity in the BHI broth over a period of 180 days was observed. The Friedman test was used for statistical analysis. RESULTS: EC40™ varnish showed the least leakage at 180 days, and was statistically similar to 2% CHX. No significant differences were observed between the group without final irrigation and the 2% CHX group or 0.2% CHX + 0.1% CTR. CONCLUSIONS: In this ex vivo study, EC40™ showed the longest delayed coronal leakage of E. faecalis, although without significant differences from 2% CHX.

Decalcifying effects of antimicrobial irrigating solutions on root canal dentin.

OBJECTIVE: The aim of this study was to determine the decalcifying efficacy of 7% maleic acid (MA), 2% chlorhexidine (CHX), and combinations of 7% MA + 0.2% cetrimide (CTR) and 2% CHX + 0.2% CTR, in four time periods. STUDY DESIGN: Four specimens per tooth were obtained from a 2-mm thick slice of the cervical third of the root of ten human incisors. At 1, 2, 3 and 5 minutes of immersion, the concentrations of Ca2+ were measured by atomic absorption spectrophotometry. The results were analyzed using the Mann-Whitney U-test. RESULTS: Statistically significant differences were seen for the extracted calcium in all time periods. The amount of calcium extracted by 7% MA was the highest at all four immersion times, followed by 7% MA + 0.2% CTR. Two percent CHX and its combination with 0.2% CTR extracted virtually no calcium. CONCLUSIONS: The decalcifying capacity of 7% MA and 2% CHX diminished when combined with 0.2% CTR.

Eradication of enterococci biofilms by lactic acid alone and combined with chlorhexidine and cetrimide.

OBJECTIVE: The antimicrobial activity of lactic acid (LA) alone or in combination with chlorhexidine (CHX) and cetrimide (CTR) against three Enterococcus faecalis strains, E. faecalis ATCC 29212, E. faecalis EF-D1 and E. faecalis U-1765, one Enterococcus durans strain and one dual-species biofilm was investigated. STUDY DESIGN: The irrigating solutions tested were 20%, 15%, 10%, 5% and 2.5% LA, alone and in combination with 2% CHX and with 0.2% CTR. The biofilms were grown in the MBECTM high-throughput device for 24 hours and exposed to the solutions for 30 seconds and 1 minute. "Eradication" was defined as 100% bacterial kill. RESULTS: Twenty percent LA eradicated all enterococci biofilms after 30 seconds contact time. The association of LA+0.2% CTR achieved better results than LA alone, in contrast with the results obtained using LA+2% CHX. E. durans was eradicated by all the tested solutions at 1 minute. The dual-species biofilm, E. faecalis ATCC 29212+E. durans, gave intermediate values of the pure cultures. CONCLUSIONS: LA is capable of eradicating enterococci biofilm at a concentration of 20%. The combination of lower concentrations with 0.2% CTR achieved eradication after 1 minute.

Antimicrobial activity and enterococcus faecalis biofilm formation on chlorhexidine varnishes.

OBJECTIVE: To evaluate, in vitro, the antimicrobial activity and biofilm formation of three chlorhexidine varnishes in four E. faecalis strains: E. faecalis ATCC 29212, E. faecalis EF-D1 (from failed endodontic treatment), E. faecalis 072 (cheese) and E. faecalis U-1765 (nosocomial infection), and one E. durans strain (failed endodontic treatment). STUDY DESIGN: The direct contact test was used to study the antimicrobial activity. Bacterial suspensions were exposed for one hour to EC40, Cervitec (CE) and Cervitec Plus (CEP) varnishes. "Eradication " was defined as 100% bacterial kill. The formation of enterococci biofilms was tested on the surface of the varnishes after 24 hours of incubation and expressed as percentage of biofilm reduction. RESULTS: EC40 eradicated all strains except E. faecalis ATCC 29212, where 98.78% kill was achieved. CE and CEP showed antimicrobial activity against all the strains, but most clearly against E. durans and E. faecalis 072. EC40 completely inhibited the formation of biofilm of E. faecalis ATCC 29212, E. faecalis 072 and E. durans. CE and CEP led to over 92% of biofilm reduction, except in the case of E. faecalis U-1765 on CEP (76.42%). CONCLUSION: The three varnishes studied were seen to be effective in killing the tested strains of enterococci and in inhibiting the formation of biofilm, the best results being observed with EC40.

In vitro Enterococcus faecalis biofilm formation on five adhesive systems.

OBJECTIVE: To determine the E. faecalis biofilm formation on the surface of five adhesive systems (AS) and its relationship with roughness. STUDY DESIGN: The formation of E. faecalis biofilms was tested on the surface of four dual-cure AS: AdheSE DC, Clearfil DC Bond, Futurabond DC and Excite DSC and one light-cure antimicrobial AS, Clearfil Protect Bond, after 24 hours of incubation, using the MBEC high-throughput device. RESULTS: E. faecalis biofilms grew on all the adhesives. The least growth of biofilm was on Excite DSC, Clearfil Protect Bond, and the control. Futurabond DC resulted in the greatest roughness and biofilm amount. There was a close relationship between the quantity of biofilm and roughness, except for Clearfil Protect Bond, which showed little biofilm but high roughness. CONCLUSION: None of the tested AS prevented E. faecalis biofilm formation, although the least quantity was found on the surface of Clearfil Protect Bond.

Residual effectiveness of final irrigation regimens on Enteroccus faecalis-infected root canals.

INTRODUCTION: The application of a final irrigating solution that remains active over a fairly long period of time stands as one strategy for preventing bacterial recolonization or eliminating the bacteria that persist after root canal treatment. The aim of this study was to evaluate the residual antimicrobial activity of four final irrigation regimens in root canals contaminated with Enterococcus faecalis. METHODS: Biofilms of E. faecalis were grown in uniradicular roots for 4 weeks. After preparing the roots chemomechanically, four final irrigation regimens were applied: (1) group EDTA-NaOCl, 17% EDTA followed by 5.25% sodium hypochlorite (NaOCl); (2) group MA-NaOCl, 7% maleic acid (MA) followed by 5.25% NaOCl; (3) group EDTA-CHX + CTR, 17% EDTA followed by 2% chlorhexidine (CHX) + 0.2% cetrimide (CTR); and (4) group MA-CHX + CTR, 7% MA followed by 2% CHX + 0.2% CTR. Samples were collected for 60 days to denote the presence of bacterial growth. The Fisher exact test was used to compare the percentages of specimens without E. faecalis regrowth. RESULTS: All root canals in which the final irrigant was 5.25% NaOCl yielded positive cultures on the fifth day. Groups EDTA-CHX + CTR and MA-CHX + CTR with a final irrigation of 2% CHX + 0.2% CTR showed respective percentages of samples without regrowth of 72.1% and 66.8% at 60 days. There were no statistically significant differences between these groups. CONCLUSIONS: The combination of 2% CHX + 0.2% CTR would be an effective alternative final irrigation regimen given its antimicrobial action over time.

Residual and antimicrobial activity of final irrigation protocols on Enterococcus faecalis biofilm in dentin.

INTRODUCTION: The use of root canal irrigating solutions exerting antimicrobial activity and prolonged residual activity is desirable in order to control dentin infection and delay reinfection of the root canal. The aim of this study was to evaluate the residual antimicrobial activity and the capacity to eradicate Enterococcus faecalis biofilm of different irrigating solutions, alone and in combination, in a dentin-volumetric test. METHODS: Solutions of 2.5% sodium hypochlorite (NaOCl), 2% chlorhexidine (CHX), 0.2% cetrimide (CTR), 17% ethylendiaminetetraacetic (EDTA), 7% maleic acid (MA), and regimens of 2.5% NaOCl followed by 17% EDTA or 7% MA and 0.2% CTR or 2% CHX were used to determine their residual activity by exposing treated dentin blocks to E. faecalis for 24 hours. Antimicrobial activity was assayed on 3-week biofilm formed on dentin blocks. Results of residual activity and antimicrobial activity were respectively expressed as the inhibition percentage of biofilm formation and the kill percentage of biofilm. RESULTS: A 2% CHX and 0.2% CTR solution showed 100% biofilm inhibition; 2.5% NaOCl showed the lowest residual activity (18.10%). The kill percentage of 2.5% NaOCl and 0.2% CTR was 100% followed by 7% MA and 2% CHX, whereas 17% EDTA was the least effective (44%). Solutions of 7% MA or 17% EDTA followed by 0.2% CTR or 2% CHX showed 100% residual and antimicrobial activity. CONCLUSIONS: A 0.2% CTR solution alone and the combinations in which 2% CHX or 0.2% CTR was the final irrigating solution achieved the maximum residual and antimicrobial activity.

An in vitro evaluation of two dentine adhesive systems to seal the pulp chamber using a glucose penetration model.

OBJECTIVES: To evaluate the sealing capability of Cavit™ G with or without Clearfil™ S3 Bond and Prime & Bond NT placed in the pulp chamber. STUDY DESIGN: Forty single rooted premolars, extracted for orthodontic and periodontal reasons, with intact coronal surface and mature apices, were standardized to a length of 15 mm. The teeth were instrumented, filled with a gutta-percha master cone and divided into three groups to obturate the pulp chambers: Cavit™ G; Clearfil™ S3 Bond plus Cavit™ G and Prime & Bond® NT plus Cavit™ G. A glucose leakage model was used for evaluating the coronal microleakage. The Mann-Whitney test was used to evaluate the differences in the means of the glucose leakage. RESULTS: An increase in glucose penetration was observed during the first week in groups Cavit™ G and Cavit™ G+PBNT. The glucose penetration values of all groups were similar at 30 and 45 days, and there were no significant differences among them in both time periods (p=0.736 and p=0.581, respectively). CONCLUSIONS: The adhesive systems did not improve the capability of Cavit™ G to seal the pulp chamber over time.

Intraorifice sealing ability of different materials in endodontically treated teeth.

OBJECTIVES: To evaluate Cavit TM G, ProRoot TM MTA and Tetric® EvoFlow as intraorifice barriers to prevent coronal microleakage in root canal treatment. STUDY DESIGN: Forty-two human single rooted teeth were divided randomly in three experimental groups of 10 specimens each and two control groups. The experimental groups were prepared with hand instrumentation and cold lateral condensed technique of the gutta-percha. Four millimetres of coronal gutta-percha were removed and replaced by one of the following filling materials: Cavit TM G, Tetric® EvoFlow or ProRoot TM MTA. In the experimental groups, leakage was measured by the concentration of leaked glucose in the apical reservoir at 1, 7, 30, and 45 days, using the enzymatic glucose oxidase method. Data were analyzed by means of Mann-Whitney U and Kruskal-Wallis tests at α=0.05. RESULTS: The glucose penetration results of three experimental groups increased gradually over time. No significant differences were found among groups at 24 hours and 1 week. At thirty and forty-five days, Cavit TM and Tetric® EvoFlow values were significantly different (p=0.007 and p=0.023, respectively). CONCLUSIONS: The sealing ability of the Cavit TM G, ProRoot TM MTA and Tetric® EvoFlow used as intraorifice materials tends to be similar over time.

Antimicrobial activity of maleic acid and combinations of cetrimide with chelating agents against Enterococcus faecalis biofilm.

INTRODUCTION: Chelating agents, such as EDTA or citric acid, can be incorporated into irrigants in order to provide different properties in a single compound. Maleic acid has recently been proposed as an alternative irrigant to EDTA given its better smear layer removal and biocompatibility; however, its antimicrobial activity is not known. The purpose of the present study was therefore to evaluate the in vitro capacity of maleic acid in eradicating Enterococcus faecalis biofilms and to evaluate the combinations of cetrimide with maleic acid, citric acid, and EDTA. METHODS: E. faecalis biofilms were grown in the MBEC high-throughput device (Innovotech; Edmonton, Alberta, Canada) for 24 hours and exposed to the irrigating solutions for 30 seconds and 1 and 2 minutes. "Eradication" was defined as 100% bacterial kill. The Student t test was used to compare the efficacy of the irrigant combinations. RESULTS: Maleic acid eradicated E. faecalis biofilms at a concentration of 0.88% after 30 seconds and at 0.11% after 2 minutes of contact time. When combined with 0.2% cetrimide, it eradicated the biofilms at all three times of exposure. The combination of 0.2% cetrimide with either 15% EDTA or 15% citric acid gave 100% bacterial kill after one minute of contact with the biofilms. CONCLUSIONS: Maleic acid showed antimicrobial activity against E. faecalis biofilm both alone or in association with cetrimide from 30 seconds onward and the combination of EDTA and citric acid with cetrimide eradicated biofilm after 1 minute of contact.

Long-term sealing ability of GuttaFlow versus Ah Plus using different obturation techniques.

OBJECTIVE: To compare the long-term sealing ability of GuttaFlow® using different obturation techniques. STUDY DESIGN: Three hundred teeth, prepared with a crown-down technique, were divided into thirty experimental groups (n=10) to evaluate the apical and coronal leakage, at 3, 30 and 120 days, of lateral compaction gutta-percha+AH Plus TM, lateral compaction gutta-percha+GuttaFlow®, single cone+AH Plus TM, single cone+GuttaFlow®, and GuttaFlow® only. RESULTS: Both coronal and apical leakage, at the three times of measurement, no significant differences were found among GuttaFlow®+lateral compaction gutta-percha and GuttaFlow®+single cone groups, whereas the only GuttaFlow® reached the highest leakage values at 30 and 120 days. AH Plus TM, using both techniques, showed high levels of leakage after 120 days to the coronal leakage and after 30 days to the apical leakage when compared silicon based sealer. CONCLUSION: GuttaFlow®, using with lateral compaction and single cone techniques, shows a greater apical and coronal sealing ability than AH Plus TM over time. GuttaFlow® when used as only creates a poorer sealing when used with lateral compaction gutta-percha or single cone techniques.

Effectiveness of the EndoActivator System in removing the smear layer after root canal instrumentation.

INTRODUCTION: Elimination of the smear layer after root canal instrumentation requires the use of irrigating solutions. This cleaning can be completed with passive ultrasonic or sonic irrigation. The aim of this study was to evaluate the effectiveness of the EndoActivator System in removing the smear layer after rotary root canal instrumentation, with and without a final flush of 17% ethylenediaminetetraacetic acid (EDTA) solution, in coronal, middle, and apical thirds. METHODS: Forty single-canal teeth were decoronated and randomly divided into 4 groups (n = 10). The groups were instrumented by using Mtwo System. EndoActivator was used with a final rinse of 1 mL of 17% EDTA or 4% NaOCl for 1 minute. The roots were longitudinally split and were grooved in the coronal, middle, and apical thirds. Scanning electron microscopy digital photomicrographs at 400x were taken to evaluate the amount of smear layer in each third. RESULTS: The NaOCl/EndoActivator group did not remove any smear layer of the root canal wall (100% in the coronal, middle, and apical thirds). In the groups that used 17% EDTA (with or without EndoActivator), the smear layer was eliminated completely (100%) in the coronal third, but the amount of removal was less in the other two thirds. The comparisons between NaOCl versus NaOCl/EndoActivator groups and EDTA/NaOCl versus EDTA/EndoActivator/NaOCl groups showed no significant differences in root canal thirds. CONCLUSIONS: The EndoActivator System did not enhance the removal of smear layer as compared with conventional Max-I-Probe irrigation with NaOCl and EDTA.

Eradication of Enterococcus faecalis biofilms by cetrimide and chlorhexidine.

INTRODUCTION: Enterococcus faecalis is the most commonly isolated bacteria from root canals of teeth with persistent periapical periodontitis. Its ability to grow as a biofilm impedes the elimination of E. faecalis by using irrigating solutions. The purpose of this study was to assess the efficacy of cetrimide and chlorhexidine (CHX), alone and in association, in combined and alternating form, in eradicating biofilms of E. faecalis. METHODS: Biofilms grown in the MBEC-high-throughput device for 24 hours were exposed to irrigating solutions for 30 seconds and 1 and 2 minutes. Eradication was defined as 100% kill of biofilm bacteria. The Student t test was used to compare the efficacy of the associations of the 2 irrigants. RESULTS: Cetrimide eradicated E. faecalis biofilms at concentrations of 0.5%, 0.0312%, and 0.0078% at 30 seconds and 1 and 2 minutes of contact time, respectively. CHX did not eradicate the biofilms at any of the concentrations (4% initial concentration) or times assayed. The association of 0.1% and 0.05% cetrimide with any concentration of CHX, whether in combined or alternating application, effectively eradicated E. faecalis biofilms at all the contact times tested. Eradication was also achieved with 0.02% and 0.01% cetrimide at 2 minutes. Statistical analysis revealed significantly better results with alternating rather than combined use of cetrimide and CHX (P < .05). CONCLUSIONS: The associated use of cetrimide and CHX provided better results than their applications as single agents against E. faecalis biofilms, and the alternating application was significantly more effective than the combined mode of application.

Cytotoxic effects of two acid solutions and 2.5% sodium hypochlorite used in endodontic therapy.

AIM: To evaluate the cytotoxicity of 15% citric acid, 5% phosphoric acid and 2.5% NaOCl on cultured fibroblasts using MTT colorimetric assay. METHODOLOGY: Irrigating solutions of 5% phosphoric acid, 15% citric acid, and 2.5% NaOCl, diluted at 0.1% and 0.5%, were applied to cell cultures of 3T3L1 fibroblasts. The cell viability was determined by means of MTT colorimetric assay after a period of 1, 6 and 24 hours. Percentages of cell viability were analyzed using the Kruskal-Wallis test for global comparisons and the Mann-Whitney U-test for pairwise comparisons. RESULTS: The percentage of cell viability diminished progressively over a 24 hour period in all solutions at both dilutions. At 0.1% dilution, 2.5% NaOCl (63.39%) and 15% citric acid (53.91%) showed the highest percentage of cell viability (p=0.083). At 0.5% dilution, 2.5% NaOCl again showed the highest cell viability value (48.51%). CONCLUSIONS: The irrigating solution with the highest percentage of cell viability was 2.5% NaOCl at both 0.1% and 0.5% dilutions. A very low percentage of cell viability was obtained with 15% citric acid and 5% phosphoric acid at 0.5% dilution.

Measurement of dental implant stability by resonance frequency analysis: a review of the literature.

Dental implant treatment is an excellent option for prosthetic restoration that is associated with high success rates. Implant stability is essential for a good outcome. The clinical assessment of osseointegration is based on mechanical stability rather than histological criteria, considering primary stability (absence of mobility in bone bed after implant insertion) and secondary stability (bone formation and remodelling at implant-bone interface). The aim of this study was to review the literature on Resonance Frequency Analysis (RFA) as a method for measuring dental implant stability. An online search of various databases was conducted on experimental and clinical research published between 1996 and 2008. The studies reviewed demonstrate the usefulness of RFA as a non-invasive method to assess implant stability. Further research is required to determine whether this system is also capable of measuring the degree of dental implant osseointegration.

Effectiveness of a manual glide path on the preparation of curved root canals by using Mtwo rotary instruments.

INTRODUCTION: Nickel-titanium rotary instruments reduce procedural errors and the time required to finish root canal preparation. The goal of this study was to evaluate the effectiveness of a manual glide path on the preparation of curved root canals with Mtwo rotary system. METHODS: Forty buccal root canals with angles of curvature between 25 to 76 degrees were randomly divided into 4 groups (n = 10); 2 groups were instrumented with Mtwo instruments to the full length, and in the other 2 groups a glide path with #08-15 K files was performed before instrumentation with Mtwo system. Digital double radiographic technique was used to determine apical transportation and the change in angle of curvature. Also working time was calculated. RESULTS: No statistically significant differences in the angle of canal curvature, apical transportation, and the working time were found between groups with glide path and no glide path. No significant differences were found when comparing the results of 3 variables between degrees of curvature. CONCLUSION: The use of a manual glide path before Mtwo rotary system did not influence the apical transportation in curved root canals.

Effect of post space preparation on apical seal: influence of time interval and sealer.

OBJECTIVE: To assess the efficacy of two sealants to preserve the apical seal after root canal preparation and cementation of posts at 24 h or 72 h after endodontic treatment. STUDY DESIGN: Sixty human single-root teeth were instrumented and obturated using lateral compaction technique with EndoFill [30] or AH-Plus) [30] and were prepared in one of three ways, leaving a 3 mm gutta percha remnant in all cases: without cast post preparation, with preparation after 24 h or after 72 h. After cementing the posts, the specimens were thermal cycled at 5 and 55 degrees C in water baths, submerged in 2% methylene blue dye for 72 h, embedded in acrylic resin and cut transversally into three 1-mm apical sections. Dye leakage was quantitatively assessed as the percentage leaked area. RESULTS AND CONCLUSION: Comparison of the apical sections showed significant differences in leakage with both sealers among the three preparation groups (p<0.001). No significant differences between sealers were found in any preparation group or in the same sections.