جستجوی مقالات مرتبط با کلیدواژه « gutta percha » در نشریات گروه « پزشکی »

This study aimed to compare the effectiveness of the Tagger technique and the lateral condensation technique with different obturation cements in achieving optimal apical sealing in endodontic treatments. An in vitro study was conducted on 68 extracted human upper or lower first premolars. Teeth were randomly divided into four experimental groups (n=17) based on two obturation techniques and endodontic sealers employed, as follows: Group 1, Tagger technique with the zinc oxide-eugenol sealer; Group 2, Tagger technique with the resin-based sealer; Group 3, lateral condensation technique with zinc oxide-eugenol sealer, and Group 4, lateral condensation technique with resin-based sealer. Homogeneity of the gutta-percha mass and apical obliteration were evaluated under a digital stereomicroscope. Data were analyzed using the chi-square test, and a P-value<0.05 was considered statistically significant. Most group specimens exhibited non-homogeneous gutta-percha, whereas apical obliteration was achieved in a significant proportion of samples across all groups. No significant difference was found between the study groups either in the homogeneity of the gutta-percha mass (P=0.978) or in the optimal apical obliteration (P=0.782). The study found no significant difference in the effectiveness of the Tagger hybrid and lateral condensation techniques using different sealers in achieving optimal apical sealing and gutta-percha homogeneity. This highlights the critical role of the clinician's expertise in ensuring successful endodontic outcomes.

The present study aimed to evaluate the bond strength of Sure-Seal Root as a new bioceramic-based sealer, and compare it with other sealers, including an epoxy resin-based sealer (AH-Plus), zinc oxide eugenol (ZOE) and a mineral trioxide aggregate-based sealer (MTA Fillapex).

In this in vitro study, 40 extracted mandibular premolars were randomly assigned into 4 groups (n=10) according to the type of sealer applied as follows: Group 1: AH-Plus, Group 2: MTA-Fillapex, Group 3:  Sure-Seal Root, and Group 4: ZOE. The canals were prepared and obturated with gutta-percha and the corresponding sealer. The samples were sectioned into horizontal segments, and the push-out bond strength was determined using a universal testing machine at the coronal, middle, and apical root thirds. The data were analyzed by repeated measures ANOVA, and the significance level was set at P<0.05.

There were no significant differences in the push-out bond strength between groups in the coronal third (P>0.05). In the middle third, AH-Plus exhibited significantly greater bond strength compared to Sure-Seal Root and ZOE sealers (P<0.05), whereas MTA-Fillapex was not significantly different from the other groups (P>0.05). In the apical third, both AH-Plus and MTA-Fillapex showed significantly greater push-out bond strength than Sure-Seal Root and ZOE sealers (P<0.05).

AH-Plus sealer exhibited the highest and ZOE showed the lowest bond strength. Sure-Seal Root indicated promising bond strength results when compared to ZOE and MTA-Fillapex. The push-out bond strength of all sealers to dentin increased from the coronal to the apical third.

This study aimed to evaluate if the apical patency can influence the adaptation of the master cone of gutta-percha, quantifying the volume of voids and areas at the last 2 mm of the working length (WL).

Sixty distobuccal canals of extracted upper molars were divided into 3 groups (n=20) based on the patency length (A: passed 1 mm beyond the apical foramen (AF), B: at the AF and C: 1 mm short of the AF) with the Easy ProDesign Logic 25/0.01 file. Each group was subdivided into 2 subgroups (n=10) based on the WL established to prepare the root canal (1: 1 mm short of the AF or 2: at the AF) with the Easy ProDesign Logic 25/0.05 file. After the scan, void volumes were calculated from the last 2 mm of the WL and void areas at 0 mm, 1 mm and 2 mm of the last of WL, as well as the relation between the tip and taper of the master cone with the amount of void volume and areas. To investigate statistically significant differences, we used the Kruskal-Wallis statistical test.

There were more voids in volume when patency was achieved 1 mm beyond the AF and the root canal preparation was conducted at 1mm short of the AF (A1 group). Furthermore, the same group showed more voids areas, mainly on the last millimeter of WL.

Achieving apical patency at 1 mm beyond the AF followed by instrumentation 1 mm short of the AF created more voids between the master gutta -percha cone and the root canal wall, especially on the last millimeter of

Statement of the Problem:

 The success of root canal therapy depends on root canal irrigation, disinfection, and sealing of root canal. Wettability and roughness of root dentine surface are important factors in root canal disinfection and sealing.

This study aimed to assess the effect of chloroform application on roughness and wettability of the root canal walls in endodontic retreatment.

This in vitro experimental study evaluated 70 sound extracted human anterior teeth. The specimens were then randomly assigned to 7 groups as follows: Chloroform (group 1), 1g gutta percha+chloroform (group 2), 2g gutta percha+ chloroform (group 3), 1g gutta percha+ 1g sealer+ chloroform (group 4), 2g gutta perch+ 2g sealer+chloroform (group 5), 1g sealer + chloroform (group 6) and 2g sealer + chloroform (group 7). One drop of distilled water was placed on each tooth to measure the contact angle and wettability. Photographs were obtained of an area measuring 50×50 µm2 in three directions under an atomic force microscope to measure the roughness. The tooth blocks were exposed to the abovementioned mixtures for 10 min, and then rinsed with saline. The roughness and wettability of each sample were measured before and after treatment. Data was analyzed using one-way ANOVA and Tukey’s test.

The roughness of all groups significantly decreased following treatment, except for groups 1 and 4. The contact angle increased in all groups after treatment (except for the chloroform group), which indicated decreased wettability. The roughness and the contact angle have shown no correlation.

Application of chloroform for removal of gutta-percha and sealer in endodontic retreatment decreases the roughness and wettability of dentine.

Complete removal of gutta-percha from the root canal system and its remnants is a challenge in endodontic retreatment. This ex-vivo study aimed to assess the efficacy of XP-Endo Finisher R (XEFR) in removing root filling remnants from straight canals of mandibular premolars in root canal retreatment.  

In this ex-vivo study, 30 single-rooted mandibular premolars with straight roots were selected. The root canals were instrumented and filled. Retreatment was then performed using D RaCe system. Teeth were then randomized into two groups of A and B (n=15). In group A, root canal retreatment was completed with XEFR. In group B, XEFR was not used. To evaluate the filling material remnants, the roots were split into halves and assessed under a stereomicroscope and photographed. The amount of remaining gutta-percha in the coronal, middle and apical thirds of the roots was measured by AUTOCAD software and analyzed with two-way ANOVA.

The amount of residual filling material was significantly lower in the coronal, middle and apical thirds and the entire root length in XEFR group (P<0.001).

 Use of XEFR significantly decreased the residual root filling material in the root canals.

Decontamination of gutta-percha (GP) cones is recommended before placement in the root canal system. However, the incidence of contamination is still a matter of debate. The present study aimed to evaluate the contamination of GP cones before and during clinical use by general dentists.

In this in vitro study, 120 GP cones (#20) were examined for incidence of contamination. First, 30 GP packages were opened under aseptic laboratory conditions, and two cones were randomly selected for the laboratory tests. Next, the initially sampled packages were distributed among 30 general dentists and then they were asked to use them clinically for 7 days and then the packages were collected for the microbial tests. The collected cones were placed in tubes containing thioglycolate medium and incubated at 37℃ for 21 days. Bacterial growth was detected by presence of turbidity and comparison with the control groups. A sample was collected from the tubes showing turbidity and plated in blood agar and also underwent Gram-staining, followed by colony counting. Data were analyzed using the Chi-square and paired sample t-test (alpha=0.05).

None of the 60 samples from initial sampling of packages showed contamination. However, in secondary sampling after clinical use, 8.3% of GP samples were positive for contamination. There was a statistically significant difference in contamination of packages before and after clinical use (P= 0.02).

Within the limitations of this study, it can be concluded that GP cones can become infected after opening the package and in the process of clinical use.

This study aimed to evaluate the efficacy of ProTaper, Mtwo, and WaveOne retreatment files and Hedstrom files for removal of gutta-percha from the straight root canals using cone-beam computed tomography (CBCT).

Forty freshly extracted single-rooted and single-canal teeth were selected for this study. The teeth were decoronated, and biomechanical preparation was performed up to #30 K-file. The root canals were obturated using lateral compaction technique with gutta-percha and Resilon sealer. The teeth were then randomly divided into 4 groups, and CBCT images were obtained. All the canals were then retreated with either ProTaper retreatment files, Mtwo retreatment files, WaveOne files, or Hedstrom files. The surface area of the remaining filling material after the retreatment procedure was quantified by CBCT. Statistical analysis was performed via one-way ANOVA and the Tukey-Kramer multiple comparisons test.

None of the file systems could completely remove the filling material from the canals. Data analysis revealed significant differences between the groups in the apical and middle thirds (P<0.05).

All the file systems left some filling material in the canals. Mtwo retreatment files had maximum efficacy for removal of filling materials in comparison with other files. WaveOne files can also be used for root canal retreatment.

Different materials cause artifacts in cone-beam computed tomography (CBCT) images, which, in turn, reduce the quality of images. The aim of this study was to investigate the abundance of artifacts induced by different root canal therapy sealers with two different CBCT resolutions.

Roots of four maxillary central phantom teeth were prepared using rotary files in three steps. In the first step, the first tooth was scanned first without gutta-percha and then with gutta-percha No. 25. Gutta-percha No. 25 with resin, the zinc oxide-eugenol (ZOE)-based sealer and the ceramic-based sealer were placed in the teeth No. 2, 3 and 4, respectively. The second step was performed similar to the first step, except that gutta-percha No. 35 was used in the tooth No. 1 with resin- and ZOE-based sealers in the teeth No. 2 and 3. due to the lack of access to the ceramic-based sealer that was not used to continue the study . In the third step, canal obturation was performed in the teeth No. 2 and 3 with resin and ZOE-based sealers. At each step, three CBCT scans were obtained in high and standard resolution conditions. Contrast-to-noise ratio was obtained in three root plans, and the data were analyzed.

Gutta-percha alone produced more artifacts than gutta-percha with sealers. Moreover, ZOE-based sealers induced more artifacts than other sealers. There was no significant difference between the three steps. Similarly, at different resolutions, there was no significant difference between gutta-percha and sealer artifacts. The ZOE-based sealers had more artifacts at 1/3 apical whereas resin sealers had more artifacts at 1/3 coronal.

The higher artifact of gutta-percha in comparison with gutta-percha and sealer and the artifact decrease in the combination of gutta-percha and resin-based sealer than ZOE-based sealer has led us to recommend the use of resin-based sealer while root canal therapy in order to better evaluation of the CBCT Images of root canal.

 The predictability of successful non-surgical endodontic retreatment is directly related to it’s ability to completely cleanse and remove obturation material from the canal system. The purpose of this study was to evaluate the removal of gutta-percha from curved canals using three final irrigation

passive ultrasonic irrigation (PUI) with a 20/01 E1 insert (Irrisonic); XP-endo Finisher (XPF); and Easy Clean (EC). Methods and Materials: Forty mesial roots of mandibular molars with an angle of curvature between 10° and 20°, two canals, and independent foramina were cut into 16-mm sections. The canals were instrumented using the Reciproc system (R25) and filled with a #25 gutta-percha cone and AH-Plus sealer by the continuous-wave condensation technique. The roots were double-sealed with Coltosol and photopolymerizable resin and stored at 37°C and 100% humidity for 30 days. They were then randomized into 4 groups (n=10): control (C), PUI, XPF, and EC. All specimens were scanned using cone-beam computed tomography (CBCT), and fill volume data (in square pixels) were calculated before retreatment, after retreatment, and after final irrigation. The images were analyzed using Tps Dig software 2.32 by two blinded, calibrated examiners (intra-class correlation coefficient=0.9967). The results were analyzed in BioEstat 4.0. The nonparametric Kruskal-Wallis test with Dunn's post-hoc and Friedman comparison were applied. Significance was accepted at 5% (P<0.05). 

None of the final irrigation protocols completely removed remnants of obturation material from the root canal systems (P>0.05). On comparative analysis with specimens divided into thirds, all methods were found to remove material equally, with no significant differences (P>0.05). 

Based on this in vitro study, the additional cleaning methods tested were equivalent to each other and did not lead to an improvement in the removal of residual obturation material.

The aim of this study was to investigate the accuracy of Cone-beam computed tomography(CBCT) in detecting the horizontal root fractures (HRFs) in teeth with and without gutta-percha.

This in vitro study was performed on 100 mandibular and maxillary single-rooted teeth. In 55 samples, the canals were prepared. Then, the horizontal fracture was induced randomly in 56 (29 with gutta-percha, 27 without gutta-percha) samples. The samples were mounted on a wax rim, and the CBCT scan was provided. The scans were examined by two endodontists twice with two-week interval. Data were analyzed using IBM SPSS 20.0 software (IBM Corp., Armonk, IL, USA). Sensitivity, specificity, accuracy, positive predictive value (PPV), negative predictive value (NPV), likelihood ratio (LR +, LR -) with 95% confidence interval were calculated.

The sensitivity and specificity were 72% and 100% for the group with gutta-percha as well as 89% and 100% for the group without gutta-percha, respectively. The coefficient of agreement for each observer within two observations was 0.940±0.034 and 0.960±0.028 (P<0.001). The inter observer agreement was 0.092±0.039 (P<0.001).

The CBCT scans have high accuracy in diagnosis of horizontal root fracture and gutta-percha although they reduce the diagnostic accuracy with no significant effect.

Different methods have been proposed for rapid disinfection of gutta-percha (GP) cones. This study aimed to assess the efficacy of low-pressure radiofrequency cold plasma (LRFCP) in disinfection of GP cones compared to three chemical disinfectants.

Seventy GP cones were allocated to seven groups of 10 each. All samples were initially sterilized with ethylene oxide (EO) and subsequently inoculated with Staphylococcus aureus (S. aureus), except for the negative control group (n=10). In the experimental groups (n=50), samples were subjected to one-minute chemical disinfection [5.25% sodium hypochlorite (NaOCl), 2% chlorhexidine (CHX), and 10% Deconex® 53 PLUS) or LRFCP (30-second or one-minute). The effectiveness of disinfection was evaluated by counting the colony-forming units (CFUs). Data were analyzed using Kruskal-Wallis test (P=0.05).

S. aureus was completely eradicated in all groups. LRFCP and 5.25% NaOCl were the most effective agents in disinfection of GP cones. In addition, 2% CHX was significantly weaker than the other agents (P<0.05). Deconex® 53 PLUS (10%) was more potent than 2% CHX; however, the difference between 10% Deconex® 53 PLUS and other experimental groups was not significant (P>0.05).  

LRFCP can be assumed as a noninvasive and efficient method for disinfection of GP cones.

The most prevalent approach for the obturation of roots, which are treated endodontically, is lateral condensation. Finger spreaders insignificantly affect packing the gutta-percha cones. This survey aimed to compare the compaction index of root canal obturation obtained with Stainless Steel (SS) and Nickel-Titanium (Ni-Ti) spreaders and different gutta-percha tapers.

Forty extracted maxillary central incisors were randomly divided into 4 groups of 10 teeth. In group 1, the canals were filled with 0.02 tapered gutta-percha and SS spreader; group 2 with 0.02 tapered gutta-percha and Ni-Ti spreader; group 3, with 0.04 tapered gutta-percha and SS spreader, and group 4 with 0.04 tapered gutta-percha and Ni-Ti spreader. The compaction index was compared among the different groups using the Independent Samples t-test.

The mean compaction index for the groups that were filled with 0.02 tapered gutta-percha cones was 1.44 with the use of SS spreaders and 1.18 with the use of Ni-Ti spreader; however, the difference was not statistically significant. Furthermore, the mean compaction index for the groups that were obturated with 0.04 tapered gutta-percha cones was 1.561 with the use of SS spreaders and 1.269 with the use of Ni-Ti spreaders. Similarly, this difference was not statistically significant.

The obturation compaction index was higher when using SS spreaders and 0.04 tapered gutta-percha cones; however, the differences were not statistically significant.

The aim of this study was to determine the effect of MTAD on the expression of virulence factors of Enterococcus faecalis (E.faecalis) considering the role of Gutta-percha/AH26 or Resilon/RealSeal SE as root canal obturating materials. One-hundred and forty-four single-rooted human teeth were instrumented to a standardized apical size. Root canals were infected by E.faecalis (ATCC 29212). Ninety teeth were irrigated with MTAD and randomly divided into three groups. In two groups, root canals were obturated by either Gutta-percha/AH26 or Resilon/RealSeal SE. Root canals were kept unobturated in the third group. The remaining 54 teeth received no final irrigation. All groups were then subdivided into three timepoint subgroups in which dentin powder was obtained from each sample to determine the expression of specific virulence factors of E.faecalis (efa, esp, gel, fsr) using real-time reverse transcription polymerase chain reaction (RT-PCR). Statistical analysis was performed by one-way analysis of variance (ANOVA) and Tukey’s post-hoc test. The statistical power was set at P-value ≤0.05. MTAD was effective against the expression of most of the tested virulence factors, and Gutta-percha/AH26 increased the antibacterial efficacy of MTAD. MTAD could inhibit the expression of some known virulence factors of E.faecalis at the majority of tested timepoints. This may partly explain some of the mechanisms of antimicrobial efficacy of MTAD against this resistant microorganism which is known as one of the main causes of failure of root canal treatment

Sodium hypochlorite (5.25% NaOCl) and silver nanoparticles (70 ug/ml AgNPs) have a broad spectrum of antimicrobial efficacy for disinfecting gutta percha (GP) point, so this study was conducted to analyze the assay surface topography of GP when disinfected with AgNPs and 5.25% of NaOCl using atomic force microscopy (AFM).
In this in vitro study a total of thirty cones were taken. The samples were divided into three treatment groups: Group I and II with 70 μg/ml AgNPs and 5.25% NaOCl. The time duration was 1 min. Untreated GP points served as control group. After treatment of 1 min for each solution, the samples were positioned in the AFM. For comparison, the root mean square (RMS) was used to investigate the structure of the GP points. Unpaired t‑test and ANOVA test were used. The differences among the groups were tested by Tukey’s honestly significant difference test and were considered significant when P 5.25% NaOCl created RMS value of 202.48 nm at 1 min as compared to 70 μg/ml of AgNPs and control which produced RMS value of 44.48 nm and 24.1 nm, respectively ( 0.0001).
The study showed irregularity in the surface of GP with NaOCl and lesser deterioration with AgNPs which could affect the postoperative prognosis. In this study, it was found that NaOCl causes 10 times more surface topography deterioration of GP when compared to AgNPs at 700 times lesser concentration.

The aim of the present research was to evaluate the effectiveness of 5% malic acid, 17% EDTA and 10% citric acid solutions used to disinfect gutta-percha cones contaminated by Enterococcus faecalis (ATCC 29212).
Methods and Materials: Two hundred and ten previously sterilized gutta-percha cones were contaminated with E. faecalis at concentration of 1.5×108 CFU/mL. The cones were immersed in 5% malic acid, 17% EDTA, 10% citric acid, 1% NaOCl and 2.5% NaOCl for 1, 5 and 10 min. Then each cone was kept in Eppendorf tubes containing BHI sterile solution at 37°C for 48 h. The presence of turbidity in BHI solution was analyzed. The results were statistically analyzed by Kruskal-Wallis test and 5% Dunn comparisons. P-value was considered statistically significant when P Regardless of exposure time, 1% NaOCl and 2.5% NaOCl were the most effective agents for rapid disinfection of gutta-percha cones (P0.05).
Demineralized solutions tested were not effective for elimination of Enterococcus faecalis on the surface of gutta-percha cones.