Showing 31 results for Canal
M. Bidar , P. Ghaziani, M. Saatchi , Ma. Soluti ,
Volume 14, Issue 3 (9-2001)
Abstract
Endodontic postoperative pain is still one of the major problems for dentists. According to the researches periapical inflammation after RCT is one of the most important factors causing endodontic postoperative pain. Histamine is one of the effective chemical mediators, which produces such inflammation. So, for controlling pains after RCT, the factors reducing inflammation should be found. The aim of this study was to investigate pain control after RCT by drug prophylaxis with antihistamine (asetemizole). 60 patients were divided in 2 groups (30 patients in each group). Group 1 had a capsule of asetemizole (20mg) and the second group had a placebo capsule one hour before RCT. The patients completed the questionnaire after RCT and gave it back on the next session. The evaluated times were 1, 3, 6, 9, 12, 18, 24 and 72 h after RCT. This study indicated that asetemizole was able to reduce the moderate pericemental pain just at the 9 and 12 hours after RCT, and it was not able to reduce the spontaneous pain after RCT significantly on the evaluated times
M. Tabrizi-Zadeh , K. Farazi ,
Volume 16, Issue 1 (4-2003)
Abstract
Statement of Problem: The main objective of endodontic therapy is chemomechanical cleansing of entire pulp cavity and its complete obturation with an inert material. During this procedure, the failure of detection and inadequate cleaning of a canal will result in failed endodontic therapy. Therefore, the dentist must have enough knowledge of root canal morphology to treat a tooth successfully.
Aim: The aim of this study was to determine the number and type of root canals of mandibular incisor teeth.
Materials and Methods: In order to do this in-vitro, descriptive study, 68 non-carious mandibular incisor teethj collected from different clinics in Yazd, were immersed in indian ink, decalcified and cleared.
Results: It was found that 55.9% of the teeth had two separate canals that in 5.5% of them, the canals merged before' apical foramen. In 4.4% of these samples, two separate canals existed along the whole root.
Conclusion: Considering high percentage of two canals in lower mandibular incisors, during access preparation, more attempts in detection of the second canal, is emphasized.
B. Eftekhar ,
Volume 16, Issue 4 (1-2004)
Abstract
The use of root canal models in endodontics education is of high importance. So, in this article a new method is presented that the students can produce these models with simple and low cost instruments.These plastic models are made of polyester which is low cost, available and has the approximate cutting properties of dentin. The best molds were disposable syringes due to their low cost, availability and producing smooth surfaces on polyester models. A spreader with desired curve and tapering is used for producing canals. Rockwell A hardness coefficient of polyester is "33", which is near dentin "31" and foreign made models "35.5". Since these polyester models can tolerate up to 280°C and have acceptable resistance to chloroform, all root canal therapy techniques such as vertical condensation and retreatments are practicable. Their transparency encourage the students to work on them. As a result, the use of these models is recommended for endodontics training.
R. Sadeghi , K. Nazari Moghaddam , J Jooyandeh ,
Volume 17, Issue 3 (8-2004)
Abstract
Statement of Problem: There is a controversy about the relationship between pulpal and periodontal diseases. The interrelationship between pulp and periodontium could have an important effect on the treatment plan of the tooth.
Purpose: The aim of the present research is to evaluate root canal therapy effects on periodontal healing of teeth with chronic advanced periodontitis.
Materials and Methods: In this randomized controlled clinical trial 32 single rooted teeth which had necrotic pulp or irreversible pulpitis in 7 patients with chronic advanced periodontitis were selected based on specific criteria. Using a split mouth design, teeth were randomly put in two groups of test and control. In the test group root canal therapy ,scaling & root planing were done.In the control group, only scaling & root planing were performed. Clinical parameters including Pocket Depth (PD), Clinical Attachment Level (CAL), mobility, pattern of bone destruction and plaque index (PI) were evaluated in two groups at base line, 1 and 3 months after treatment. Appropriate tests such as paired Wilcoxon and Mann-Whitney were performed.
Results: Statistically significant reductions were found in the test group when comparing baseline and one-month post treatment values for Clinical Attachment level (CAL) but not after 3-months. In the control group the CAL reductions were not statistically significant between baseline and one month post-treatment, but a increase were observed between one month and three months after treatment. There was a statstically significant difference between the test and the control groups. Other parameters didn’t show any significant differences in each group and between two groups.
Conclusion: Since clinical attachment level was the most important parameter we found it can high lighted the role of pathogene with pulpal origin in progression of periodeontal disease and it is concluded that beside periodontal treatment in some advanced periodontal cases pulp therapy maybe an effective procedure for eleminating destructive pathogens of pulp and causing periodontal healing.
A. Vahid , Sh. Noroozi , B. Golestan ,
Volume 18, Issue 3 (5-2005)
Abstract
Background and Aim: Preserving canal curvature during different phases of canal preparation is an important point. In Endodontic therapy all efforts are made to prepare canal in a way that final canal follows the primary canal curvature. The purpose of this study was to evaluate the efficacy of root canal preparation performed by students at Endodontic Department of Dental School, Tehran University of Medical Sciences.
Materials and Methods: In this retrospective study, classic method of step- back technique was investigated for preserving canal curvature in mesial roots of first mandibular molars and mesiobuccal roots of first maxillary molars between years 2000 and 2004. A randomly selected sample of 400 dental patient records was investigated by 4 observers (Endodontic department professors), searching for procedural errors. A clear explanation sheet of curvature preservation and procedural errors such as ledge formation, apical foramen transportation, zipping and stripping and a questionnaire were prepared for observers. The observers went through reliability test and kappa value for agreement between every two observers. The results were above 0.8. Data were analyzed by EPI6 statistical computer program, using Chi-Square and Fisher exact test with P<0.05 as the limit of significance.
Results: This study consisted of 152 first maxillary molars and 248 first mandibular molars. The prevalence of curvature preservation in mesial root of first mandibular molars and mesiobuccal root of first maxillary molars were 38.5% and 47.6% respectively. Procedural errors detected consisted of 33% ledge formation, 26.1% apical foramen transportation, 1.8% zipping and 4.1% stripping for mesial root of the first mandibular molars. The results for the first maxillary molars were 27%, 19%, 3.2% and 3.2% respectively.
Conclusion: The study results revealed the efficacy of endodontic education and the proficiency of junior and senior students in preparing curved posterior root canals. The results obtained in this retrospective study are comparable to prospective studies.
S. Khedmat , M. Vahdatifar ,
Volume 19, Issue 2 (5-2006)
Abstract
Background and Aim: Recent advances in technology have permitted manufacturers to produce endodontic files from NiTi alloy and rotary systems. According to manufacturers, these files maintain original canal shape better than hand files and reduce treatment time. The aim of this study was to compare a new rotary system (Race) with an older one (Profile) in maintaining the original shape of curved canal and the working length as well as the procedural accidents rate.
Materials and Methods: In this experimental study, 40 polyester blocks with curved canals (45 ), were fabricated and divided into 2 groups. After primary working length determination and staining with methylene blue, photographs were taken. Canal preparation was done with Profile and Race rotary systems according to manufacturers and working length was measured again. Canal staining by eosin was performed and photographs were taken for the second time. The two images were superimposed and changes in canals anatomy in 5 sections were recorded. Data were analyzed by t test with p<0.05 as the limit of significance.
Results: There was no significant difference in inner and outer canal walls transportation between 2 groups (P> 0.05). Changes in working lengths and procedural accidents were similar in the studied groups (P> 0.05).
Conclusion: Based on the results of this study, changes in canal anatomy and working length of simulated severely curved canals as well as procedural accidents rate are similar in two rotary systems and both are suitable for canal preparation.
Hr. Abdolsamadi , Sh. Nazari , F. Mirmotalebi , M. Shirinzad ,
Volume 19, Issue 3 (6-2006)
Abstract
Taurodontism is a rare dental anomaly in which the involved tooth has enlarged and elongated body and pulp chamber with apical displacement of the pulpal floor. Endodontic treatment of these teeth is challenging because it requires identifying the number of root canals. A case of bilateral involvement of maxillary first molar teeth is presented. Endodontic treatment of the right maxillary first molar with taurodontism was indicated due to irreversible pulpitis. In this article, we described the procedure of root canal therapy for this case.
Ms. Sheykhrezaee , F. Hosseini ,
Volume 19, Issue 4 (1-2007)
Abstract
Background and Aim: Many methods and techniques of canal preparation work well in large and relatively straight canals. However, in severely curved canals, the complexity increases markedly, and techniques rendering good results in usual cases may be unsuccessful. The aim of this study was to compare the effect of five root canal preparation techniques on original canal anatomy in simulated severely curved canals.
Materials and Methods: In this experimental in vitro study, 100 simulated canal blocks with similar hardness were made from polyester. The degree of curvature was 45º with a radius of 2.55 mm and a straight part of 8mm. The blocks were prepared with five different techniques (20 canals in each group) as follows: 1-Stepback 2- Passive step back 3- Balanced force using flex-R files 4- Balanced force using Ni-Ti hand instruments 5- Hybrid using a rotary Ni-Ti system (XtremRace). Digital photographs were taken from pre- and post instrumentation colored canals. Then images were superimposed and analyzed by an image editing software. The amount of removed material from the inner and outer canal walls was measured at five levels: 1-The canal orifice (O) 2-The halfway between the orifice and the beginning of the curve (HO) 3-The beginning of the curve (BC) 4-The apex of the curve (AC) and 5-The endpoint of preparation (EP). Additionally, the time of instrumentation, instrument failure and changes in working length were recorded. Data were analyzed by ANOVA and Kruskall-Wallis tests with p<0.05 as the limit of significance.
Results: Mean transportation was towards the outer aspect of the curve at the EP in all canals but there were no significant differences between the studied groups. At the BC point, all of the canals were transported towards the inner aspect of the curve and there were significant differences for both transportation values & direction among different groups. The highest amount of transportation was in step back and the lowest, in hybrid group. The highest transportation value was in step back and the lowest in balanced force group. Fractured and deformed instruments were observed in Flex-R files. The shortest canal preparation time was seen in XtremRace and the slowest, in Passive step back groups (P<0.001).
Conclusion: Based on the results of this study, changes in canal curvature were less with techniques using nickel titanium instruments and the fastest technique with least transportation was XtremRace.
Mh. Zarrabi, M. Bidar , H. Jafarzadeh ,
Volume 20, Issue 1 (5-2007)
Abstract
Background and Aim: Mechanical preparation of canal is one of the most important stages in root canal therapy. Various kinds of hand or rotary techniques are used for mechanical preparation of canal and each of them has advantages and disadvantages. During canal preparation, extrusion of debris from the apical foramen can result in periapical inflammation and increased pain and edema. The aim of this study was to compare hand instrumentation technique with three rotary systems (Profile, Race, Flex Master) regarding the amount of extruded debris from apical foramen during canal preparation.
Materials and Methods: In this experimental in vitro study, one hundred human extracted single rooted mandibular premolars with curvature between 0-10 degrees were selected and divided into four groups of 25 teeth each. All teeth were shortened to 15 mm length by cutting the crown. Group H was prepared by hand step back technique, group P by Profile system, group R by Race system and group F by Flex Master system. For debris collection, vials containing distilled water were used which were weighed before preparation. After the end of canal preparation, vials were completely dried and weighed again. The difference between weights of vials in two stages was the weight of debris extruded from apical foramen. The groups were compared by One-way ANOVA with p<0.05 as the level of significance.
Results: Group H had the highest mean weight of debris which showed significant difference with all three rotary groups (P<0.001). The lowest mean weight of debris was observed in group R (Race) which was significantly different from group F (Flex Master) but not significantly different from group P (Profile).
Conclusion: Based on the results of this study, race rotary system caused less debris extrusion from apical foramen compared to hand step back technique and Flex Master rotary system.
M. Zarrabian , Sn. Ostad , M. Abbasi , M. Mohseni ,
Volume 20, Issue 3 (6-2007)
Abstract
Background and Aim: Root filling materials are usually in close contact with living tissues. So their biological properties like mutagenicity and cytotoxicity are important. These properties help us determine the potential damage to periapical tissues, or potential DNA mutations, and malignant transformation of the cells. The aim of this study was to evaluate the mutagenicity and cytotoxicity of four root canal sealers: AH Plus (Dentsply, DeTrey), Ketac-Endo Aplicap (3M ESPE), Sankin Apatite III (Sankin K.K), and Tubli-Seal EWT (Kerr).
Materials and Methods: In this experimental in vitro study fresh and set specimens from AH Plus, Ketac-Endo Aplicap, Sankin Apatite III, and Tubli-Seal EWT were immersed in culture medium for 1, 2 and 7 days. Cytotoxicity was assessed using tetrazolium bromide reduction assay (MTT) after 1, 2 and 7 days exposure of diluted extracts to L929 cells. Extracts of sealers in phosphate buffer saline (PBS) were used to examine the mutagenic effects by sos-umu test according to standard procedures. Data were analyzed using one way ANOVA, Kruskall Wallis, Mann Whitney and Post hoc tests with P<0.05 as the level of significance.
Results: Extracts of all freshly mixed sealers were cytotoxic. Ketac-Endo Aplicap and Sankin Apatite III showed the lowest toxicity respectively and Tubli-Seal EWT the highest. In contrast to other sealers, the cytotoxicity of Tubli-Seal showed no decrease with time. -galactosidase did not increase significantly thus none of the sealers showed mutagenic effects.
Conclusion: Based on the results of this study, Tubli-Seal EWT showed the highest cytotoxicity with time. Other sealers showed decreasing cytotoxicity with time. No mutagenicity effects was observed in none of tested materials.
M. Tabrizizadeh , Z. Mohammadi , Mj. Barzegar Bafruyi ,
Volume 20, Issue 4 (1-2008)
Abstract
Background and Aim: Sealing the root canal system is of great importance in endodontic treatment especially in infected teeth. Several materials have been introduced for this purpose. The aim of the present study was to evaluate the sealing ability of MTA as an orthograde root filling material and compare it with laterally condensed gutta-percha with sealer.
Materials and Methods: Thirty-six extracted human maxillary central and canine teeth were used in this experimental study. After preparation and surface disinfection with 1% NaOCl solution, the crowns of the teeth were cut at cemento-enamel junction.Roots were randomly divided into four groups: two experimental groups of 15 roots each (gutta-percha with AH26 sealer and MTA) and two control groups of 3 roots each (positive and negative). After root canal preparation and filling, the sealing ability of each technique was assessed by immersion in 1% methylene blue dye for 72 hours. Then the teeth were cleared and the extent of dye penetration was measured with a stereomicroscope. Data were analyzed by T-test with P<0.05 as the level of significance.
Results: The results showed that the mean microleakage was 1.1mm (SD=2.1) in the gutta percha group and 3.4mm (SD= 2.1) in the MTA group.This difference was statistically significant (P=0.013).
Conclusion: Based on the results of this study, canal obturation with gutta-percha and AH26 sealer may provide a better apical seal compared with MTA. However, further studies on microbial leakage are needed for more precise evaluation of the sealing ability of MTA.
H. Bashizadeh Fakhar, F. Abolhasani, T. Mohtavipour,
Volume 21, Issue 1 (10-2008)
Abstract
Background and Aim: Accurate bone measurements are essential to determine the optimal size and length of dental implants. The magnification factor of radiographic images may vary with the imaging technique used. The purpose of this study was to compare the accuracy of linear tomography and panoramic radiography in vertical measurements, as well as the accuracy of linear tomography in mandibular width estimation.
Materials and Methods: In this test evaluation study, the vertical distances between the crest and the superior border of the inferior alveolar canal, marked with a metal ball, was measured by linear tomography and panoramic radiography in 23 sites of four dry mandible bones. Also the mandibular width was measured at the same sites. Then, the bones were sectioned through the marked spots and the radiographic measurements were compared with actual values.
Results: The vertical magnification factor in tomograms and panoramic radiographs was 1.79 (SD=0.17) and 1.69 (SD=0.23), respectively. The horizontal magnification of tomograms was 1.47 (SD=0.17). A significant correlation was found between the linear tomographic and actual values, regarding vertical dimensions (p<0.001, r=0.968) and width (p<0.001, r=0.813). The correlation was significant but lower in panoramic radiographs (p<0.001, r=0.795). Applying the magnification values suggested by the manufacturer, the mean difference of vertical measurements between the tomographic sections was 2.5 mm (SD=3.4) but 3.8 mm (SD=1.65) in panoramic radiographs. The mean of absolute difference in mandibular width between the tomographic sections and reality was 0.3mm (SD=1.13). In the linear tomograms, 4.3% of vertical and 56.5% of the width measurements were in the ±1mm error limit. Only 4.3% of the vertical measurements were within this range in the panthomographs. The linear regression equation between the actual values and those obtained by radiography in vertical dimensions showed that 87.5% of tomograms and 51.8% of panoramics were located in the ±1 mm error limit.
Conclusion: Based on the results of this study, the linear tomography is more accurate than panoramic radiography in mandibular height estimation. The accuracy of linear tomography in width estimation is within acceptable limits.
Sh. Javadinejad, M. Zarejahromi, A. Mirenayat,
Volume 21, Issue 3 (12-2008)
Abstract
Background and Aim: The role of applying rotary instruments in reducing preparation time and proper root canal preparation have been approved in permanent teeth. The aim of this study was to compare the rotary instruments (Hero642) and K-files in root canal preparation of primary molars. Time and canal transportation were compared.
Materials and Methods: In this experimental, invitro study, 30 human extracted primary molars with 8 mm length were selected and divided into two equal groups. After preparing access cavity, group 1was prepared by K-files and group 2 by Hero642 systems. Before canal preparation, with # 15 K-file and after canal preparation, with master apical file, canal curvature was evaluated by Weine technique using Radiovisiography. Apical transportation was calculated. Time taken for preparation was recorded by chronometer. The results were analyzed with T-test and Mann-Whitney. P<0.05 was considered as the level of significance.
Results: The average canal transportation angle was 3.42 for Hero642 group and 7.33 for K-file group (p<0.04). The mean instrumentation time was 4.28 for Hero642 group and 8.76 minutes for K-file group (p<0.001). There was a significant difference between two groups.
Conclusion: Based on the findings of this study, it is suggested to apply Hero642 rotary instrument for primary molar canal preparation due to less preparation time and less canal transposition.
F. A. Nakhjavani, Ms. Sheikhrezaie, S. Negahbani,
Volume 21, Issue 3 (12-2008)
Abstract
Background and Aim: Elimination of microorganisms and their byproducts from root canal system is one of important aims of root canal therapy. This object is gained by using of many chemomechanical techniques but with noncertain success. A new method is used of nonpathogenic bacteria for growth inhibition of pathogenic bacteria, Antibiosis, in root canal therapy.The aim of this study was in vitro evaluation of antimicrobial effect of probiotics, such as Lactic Acid Bacteria (LAB) on the infected root canal bacteria.
Materials and Methods: Isolated bacteria from infected root canal were grown and then scattered onto the muller Hinton agar plates which contain wells, LAB, extracted from dairy products, were added into these wells, Inhibition effected of LAB was determined. Furthermore the sample taken from the inhibition zone and possible resistant monoclonal bacteria also were identified, then 6 sensitive and 14 resistant samples were selected and E. faecalis species were added to them Then antimicrobial effects of LAB on these samples was reevaluated.
Results: The results showed that 66.7% of the samples were sensitive at least to one type of LAB, and 33% were resistant to all kind of LAB. Meanwhile the outgrowing anaerobic bacteria inside the inhibition zone were from the low frequency oral bacterial flora. Furthermore, adding E. faecalis to the samples caused more sensitivity of them to LAB. Mc-Neamar test recognized the difference significant.
Conclusion: This study showed that the LAB inhibit growth of the pathogenic root canal bacteriae. Furthermore, presence of E. faecalis reinforces the antimicrobial effect of LAB. It seemed that LAB maybe have potential to use in endodontic practice for elimination of root canal infections.
M. Sharifian, B. Bolhari, A. Nosrat, M. Aligholi,
Volume 22, Issue 1 (8-2009)
Abstract
Background and Aim: Researches have shown that bacteria play the main role in development of pulpal and periapical diseases. Chemo-mechanical cleaning of infected root-canal system can not remove all of the microorganisms. Thus interappointment medicaments are necessary to aid this goal. Calcium hydroxide is one of the most useful medicaments in root canal therapy, but this medicament can not eliminated all of the bacteria in root canal system. Carvacrol is an edible plant extract that has antimicrobial and anti-inflammatory effects. If this extract is effective against endodontic bacteria, it can be used as an root canal medicament.
Materials and Methods: In this experimental study, Initially, MIC and MBC of carvacrol detected with Macro broth dilution method and determined as 0.3% and 0.6%, respectively. After that, 30 single root and single canal extracted human teeth were used in this study. The number of specimens determined in a pilot study on 4 extracted teeth. After preparation to apical size # 30 with hand and rotary instruments, teeth were randomly divided into two experimental and two control groups. After culturing Enterococcus faecalis in prepared canals, we used emulsion of 0.6% carvacrol and calcium hydroxide in two A and B experimental groups for 7 days as the intracanal medicament. Microbial samples obtained before and after experiment. Then, canals with negative culture selected to obtain dentinal shaving to culture. Data obtained from microbiological samples analyzed with kruskal-wallis and Bonferroni tests.
Results: Results of this study showed that emulsion of 0.6% carvacrol has no significant difference with calcium hydroxide in elimination enterococcus faecalis after 7 days dressing (p>0.05).
Conclusion: Carvacrol can be used as an intrappointment intracanal medicament.
A. Ghorbanzadeh, B. Boulhary, P. Motahhary, A. Sharifi, H. Kashani,
Volume 22, Issue 2 (11-2009)
Abstract
Background and Aim: A considerable percentage of failure in Endodontic treatments in maxillary molars is attributed to undiscovered second mesiobuccal canal (MB2).There are different methods for discovering and accessing to this canal. The purpose of this ex vivo study was to compare the detection ability of three methods (direct look, fiberoptic loup and surgical microscope) to find MB2 after troughing with ultrasonic.
Materials and Methods: In this experimental study, we selected 90 extracted maxillary molars (45 first and 45 second molars) in which after access cavity preparation MB2 canal was not discovered by direct vision and endodontic explorer. They were divided into 3 groups (n=30). The dentinal shelf between mesiobuccal and palatal canals was eliminated by an endodontic ultrasonic tip (troughing). After that, first group was searched by direct vision, second group by a loup and fiberoptic light and third group by dental operating microscope. Data were analyzed, specificity and sensitivity were calculated.
Results: The results showed that 21%, 61%, and 92% of MB2 canals after troughing was found by direct vision, fiberoptic loup, and surgical microscope, respectively.
Conclusion: Based on the results of this study, surgical microscope and loup with fiberoptic are preferred methods for discovering MB2 canal. Troughing with ultrasonic can help find MB2 canal in all methods.
M. Salapoor, N. Farhad Mollashahi,
Volume 23, Issue 3 (12-2010)
Abstract
The goal of each root canal therapy is cleaning and obturating the entire root canal system. A thorough knowledge of root and root canal morphology and a good anticipation of their possible morphologic variations are essential and will help to reduce endodontic failure caused by incomplete root canal preparation and obturation. In this study, one case of maxillary molar with two palatal roots has been reported in a a 40-year-old woman is reported..
A. Farhad, B. Barekatain, A. Movahedian Attar, O. Niknam, P. Alavinejad,
Volume 23, Issue 4 (1-2011)
Abstract
Background and Aims: It is important to use intracanal medicaments in teeth with necrotic pulp. Calcium hydroxide is the intracanal medicament of choice in such cases. Also, Mineral Trioxide Aggregate (MTA) is a suitable root canal filling material because of its favorable characteristics. MTA can be used in some cases where calcium hydroxide is used. The purpose of this study was to evaluate the Ca++ and OH ˉ diffusion through root dentin using calcium hydroxide paste and two different brands of MTA as root canal filling materials.
Materials and Methods: In this in vitro study, the root canals of 52 single-rooted teeth were instrumented and shaped. External defects were created on the middle one-third of the root surface. 17% EDTA and 5% NaOCl were used to remove the smear layer. All surfaces except the external defects were sealed and the teeth were placed in normal saline. Ten teeth were selected as the control group. Forty-two remaining teeth were divided into three groups of 14 teeth each (A,B, and C groups). ProRoot MTA was placed in group A. Angelus MTA was placed in group B and Calcium hydroxide paste was placed in group C. After sealing the coronal access, all specimens were placed in normal saline solution. Ca++ concentration and pH were determined after 24 hours, 48 hours and one week in all groups. The data were analyzed with Repeated Measure ANOVA and Pair T- tests.
Results: Ca++ release and pH in group C was significantly higher than those in groups A and B in all time periods (P<0.001). The difference between groups A and B was not significant (P>0.05).
Conclusion: The results of this study indicate that in necrotic cases with lesion which MTA is indicated (open apex and perforation), calcium hydroxide might be better used as an intracanal dressing before using MTA as a permanent filling material.
F. Mokhtari, N. Joshan, Ar. Heshmat Mohajer, Y. Khalil Sefat,
Volume 24, Issue 3 (6-2011)
Abstract
Background and Aims: Nowadays, calcium hydroxide is used as a dressing for canal sterilization and repair progression of apical lesions. The aim of this study was to investigate the effect of calcium hydroxide as an intracanal medicament on the apical microleakage of root filling.
Materials and Methods: In this experimental study, 46 extracted single-rooted human teeth were instrumented with step-back technique to master apical file (MAF) size 35. Specimens were randomly divided into 2 groups (n = 20). In group 1, the specimens were treated with calcium hydroxide intracanal medication and in group 2, the samples did not receive any medication. The teeth were incubated in 100% humidity at 37°C for one week. After that, calcium hydroxide was removed using irrigation with normal saline and reaming with MAF. The root canals were obturated with gutta- percha and AH26 sealer using lateral compaction technique. Specimens were incubated in 100% humility at 37°C for 72 hours and then immersed in India ink for 1 week. Finally, the teeth were cleared and the maximum linear dye penetration was measured under a stereomicroscope at 4X magnification. The data were analyzed by T-test and Chi-square.
Results: There was no significant difference between the two experimental groups (P=0.068).
Conclusion: The findings of this study indicated that using calcium hydroxide as an intracanal medicament did not influence the apical microleakage after final obturation of the root canal system.
Mohamad Hosein Lotfi Kamrani, Mahdi Tabrizizadeh, Yosef Khlil Sefat, Vahid Yegane,
Volume 24, Issue 4 (1-2012)
Abstract
Background and Aims: The seal provided by a root canal filling may be compromised by post space preparation. The aim of this study was to compare coronal microleakage around cast posts and prefabricated pins.
Materials and Methods: Thirty-eight extracted single-rooted, maxillary human teeth were prepared with step back method and filled with gutta-percha and sealer. After removing 8 mm of coronal gutta-percha with peeso-reamer drills #2 in twenty canals, the teeth were divided into three groups: cast post & core, prefabricated pin, and gutta-percha (without any post or pin). After thermocycling, the samples were immersed in India ink for seven days. Finally, the specimens were cleared and the coronal microleakage of dye was then measured by the stereomicroscope. The data were analyzed by One-way ANOVA and Tukey HSD tests.
Results: According to the results, the mean dye penetration in cast posts, pins, and group without post or pin was 3.3 (0.39), 5.2 (0.47), and 7.2 (0.15) mm, respectively. There was no statistically significant difference between the groups (P>0.05).
Conclusion: Considering the importance of adequate filling of crown for prevention of microleakage, the method for coronal filling must be selected with caution. According to the results of this study, no significant difference between microleakage of cast posts and prefabricated pins was observed.
