[Synergistic antimicrobial efficacy of 2% chlorhexidine and 3% hydrogen peroxide for infected root canals of extracted human teeth: an ex-vivo study]

An endodontic irrigation solution with low toxicity and high antimicrobial activity is required in the process of endodontic treatment. Using a combination of intracanal irrigants is one solution to achieve this goal. The aim of this study was to evaluate the synergistic antimicrobial efficacy of chlorhexidine and hydrogen peroxide against bacteria in the infected extracted human root canals. Forty-two teeth with periapical lesions were chosen for this study. The teeth were extracted and preserved in normal saline at 37°C for less than 24 hours. Canals were prepared with nickel titanium rotary files [S1 to F3] and irrigated with 10cc of the respective irrigants [group 1:14 teeth irrigated with 3% hydrogen peroxide; group 2: 14 teeth irrigated with 2% chlorhexidine and group 3: 14 teeth irrigated with a combination of 3% hydrogen peroxide and 2% chlorhexidine]. Samples were obtained with paper cones before and after root canal preparation [S1, S2] and transferred to a microbiology lab for colony counting. Data were analyzed using the Kruskal-Wallis and Mann-Whitney tests. The results showed that all the understudy irrigants significantly decreased the bacterial colony count. A combination of chlorhexidine and hydrogen peroxide was significantly more effective than hydrogen peroxide. Chlorhexidine is an effective irrigant with high antimicrobial activity but its antimicrobial efficacy does not significantly increase in combination with hydrogen peroxide

Comparison of the antibacterial effect of sodium hypochlorite and aloe Vera solutions as root canal irrigants in human extracted teeth contaminated with enterococcus faecalis

Statement of Problem: The main purpose of a root canal treatment is to eliminate the bacteria and their products from the pulp space. Sodium hypochlorite has excellent antibacterial properties but also some negative features

Purpose: The aim of the present study is to compare the antimicrobial effect of Aloe Vera solution with sodium hypochlorite on E.faecalis in the root canals of human extracted teeth

Materials and Method: Sixty human extracted single rooted teeth were selected for this in vitro study. Only teeth without conditions such as cracks, internal resorption, external resorption and calcification were included in the study. Enterococcus faecalis was injected in the root canals of all teeth. The teeth were then divided into three groups randomly. Each group consisted of 20 teeth that were all rinsed with one of the following solutions: sodium hypochlorite 2.5%, Aloe vera and normal saline. Subsequent to rinsing, root canals of all teeth were sampled. The samples were cultured and growth of the bacteria was assessed after 48 hours. The number colonies of the bacteria were then counted

Results: The difference between the inhibitory effect of Aloe vera and normal saline on E.faecalis was not significant according to independent T-test [p= 0.966]. The inhibitory effect of sodium hypochlorite on E.faecalis was much greater than that of Aloe vera and normal saline [p< 0.001]

Conclusion: Aloe vera solution is not recommended as a root canal irrigator but it is suggested for the future studies to investigate the antibacterial effect of Aloe vera for longer durations and as an intracanal medicament

Comparison of apical sealing ability of lateral condensation technique in room and body- simulated temperatures [an in vitro study]

Statement of Problem: Studies reported that nearly 60% of endodontic failures have been attributed to inadequate obturation of the root canal system. Thus, complete obturation of the root canal system and proper apical seal are essential elements in the longterm success of root canal treatment

Purpose: This study aimed to compare the apical seal of lateral condensation technique in the room and in body- simulated temperature

Materials and Method: In this experimental study, 70 extracted, single- rooted, human premolar teeth were instrumented and divided up into four groups. All tooth's canals were obturated by lateral condensation technique except the teeth in the positive control group. Group 1 and 2, each with 30 teeth, were obturated in the room and intracanal temperature respectively. The other two groups were positive and negative control group each with 5 teeth. All groups except negative control were covered by two layers of nail polish. Then linear dye penetration was evaluated with a stereomicroscope. Data was analyzed with student-t test and also Kolmogorov- Smirnov Goodness- of- Fit test to make sure of data

Results: Results showed that dye penetration in group one [obturation in room temperature] was 0.6mm more than group 2 [obturation in simulated-body temperature] although this was not statistically significant [p> 0.05]

Conclusion: Under the condition of this invitro study, apical sealing ability was better in the body-simulated temperature than the room temperature, although it was not statistically significant

Comparison of MTA and CEM cement microleakage in repairing furcal perforation, an in vitro study

Statement of Problem: Sealing the perforation defect is an important factor to reduce inflammation in the area and to perform healing. Selecting the appropriate material to repair the defect is an important concern. Among the various available materials, MTA and CEM are used recently for achieving this purpose. In the current study we compare the sealing ability of these materials by evaluating their microleakage by fluid filtration method

Purpose: The purpose of this study was to compare the microleakage of MTA and CEM cement in furcal perforation in different periods of time

Materials and Method: Forty one mandibular molars were selected for this experimental study. The perforation defects were created perpendicular to the long axis of the teeth, on the furcation of the teeth and the samples were divided into 2 experimental and two control groups. The defects were sealed by CEM and MTA in each experimental group. The samples were undergone the fluid filtration test with 20 cm H2O pressure. The amount of fluid filtration was measured for each sample at 24, 72 and 168 hrs and the data were analyzed by using ANOVA and T test

Results: The experimental groups which were sealed with CEM exhibited significantly less microleakage in all determined periods of time [24, 72 and 168 hrs] than MTA groups [p< 0.001]

Conclusion: Based on the results of this study, CEM cement has a better sealing ability compared with MTA using fluid filtration method

[Evaluation of three different spreading forces using lateral condensation technique on apical leakage and tooth fracture: an in vitro study]

Lateral condensation technique is one of the most frequently used techniques for root canal obturation. There were few studies in order to determine the needed force for spreader penetration and its effect on apical seal. The purpose of this study was the in vitro evaluation of the effect of three spreader forces using the lateral condensation technique and the effect of these forces on root fractures. Eighty-five human mandibular premolar single rooted teeth without severe curvature and visible fractures were chosen and randomly divided into three groups. Each group of teeth were obturated on an acrylic model using three forces [1.6, 3 and 4.5 kg] with the lateral condensation technique. The teeth were observed under the stereomicroscope x6 again for any fracture line following clearing of the teeth and the maximum dye leakage penetration was measured for each tooth. The data were analyzed by using chi-square and Kruskal-Wallis statistical tests. All samples in the positive control group showed dye leakage but in the negative control group no sample showed any leakage. The mean dye penetration for the first [1.6 kg], second [3kg] and third [4.5 kg] groups was 0.344 mm, 0.153 mm and 0.746 mm, respectively. The 3kg force for lateral condensation technique produced a significantly better apical seal and less leakage in comparison with the other groups [P<0.05] and more fractures were observed with 4.5kg force [P<0.05]. The best force for lateral condensation in premolar teeth was 3kg and more pressure could produce more fracture

Comparison of flare up incidence in patients treated by different practitioners

Statement of Problem: Flare up is an acute exacerbation of an asymptomatic pulpal and/or periapical pathosis after commencement or termination of root canal therapy. Its incidence may be different in patients treated by different practitioners regarding their graduation status

Purpose: The aim of this study was to compare flare up incidence in patients treated by dental students of Shiraz Dental School and those whom were treated by endodontists

Materials and Method: Patients' information including age, gender, and previous history of pain and pulp vitality were taken before treatment of 383 patients. 230 of them were treated by senior dental students of Shiraz Dental School and 153 of them were treated by endodontists. Students employed conventional step back technique whereas specialists had a chance to select variety of techniques. Data, regarding the quantity of pain experienced by patients were collected 48 hours after treatment. Case was considered a flare up if the patient had experienced severe pain which hadn't been reduced either by analgesic medication or by consequent swelling. Chisquare statistic tests were used to analyze the receiving data

Results: 41 individuals [10.7%] out of 383 patients depicted flare up. 13.5% of these patients were treated by students and 6.5% were treated by endodontists. The difference was statistically significant

Conclusion: Different rate of flare up in two groups is probably due to the dissimilarity in skills, techniques and materials used by different operators

[Clinical comparison of root length measurements with electronic apex locator and conventional radiography in mandibular deciduous teeth]

Statement of Problem: Success in pulpectomy of deciduous teeth greatly depends on the accuracy of root length measurements which have mostly been done radiographically. However, X-ray risks and patient cooperation have usually been a challenge for the clinicians

Purpose: The clinical comparison of root length measurements with electronic apex locator and conventional radiography in 4-6 year old children's mandibular deciduous teeth was the aim of the present study

Materials and Method: In the current clinical trial, 15 mandibular molars with 60 canals in 4-6 year old patients who had the treatment plan of pulpectomy were chosen. The measured root lengths with apex locator and parallel technique radiography were evaluated with the same reference point. Data were analyzed using simple linear regression, coefficient of correlation, coefficient of variability and also graphic Bland Altman Plot

Results: The accuracy of electronic apex locator measurements in +/-0/5 from apical foramen was 85%. In all cases without considering pulp situation, the difference between the two techniques was not significant

Conclusion: The electronic apex locators are recommended for root length measurements of the deciduous mandibular molars without apical resorption, disregarding the pulp status, especially when initial radiographic films are available

[Comparison of the effects of bupivacaine and lidocaine as local anesthetics on the incidence of pain after root canal therapy]

Statement of Problem: Post-treatment endodontic pain is a concern of both patients and dentists. Several methods and drugs have been suggested to prevent the pain. In several studies, the use of long acting local anesthetics has been considered in the prevention of pain after some dental procedures

Purpose: The purpose of this study was to compare the effect of Bupivacaine and Lidocaine as local anesthetics on the incidence of pain after root canal therapy

Materials and Method: A total of 60 patients referring to 3 endodontists were invited to participate in this double blind clinical trial study. The patients had no history of cardiovascular disease, hypersensitivity to amide types of local anaesthetics, renal failure and hyperthyroidism. They were randomly assigned to one of the two groups: 0.5 percent Bupivacaine with 1.200000 Epinephrine or 2 percent Lidocaine with 1.100000 Epinephrine. After root canal therapy, the extent of postoperative pain was measured during 48 hours and categorized into 4 scores, 0 to 3. The results were analyzed using Mann-Whitney test for comparing the pain scores among the patients and Fischer's Exact test for evaluating the correlation between, sex, jaw position, type of pulpal disease and preoperative pain with postoperative pain

Results: Statistical analysis showed that Bupivacaine significantly reduced the incidence of flare-up after root canal therapy [p =0.002] and the need for analgesics was significantly decreased using Bupivacaine [p =0.01]

Conclusion: Long acting local anesthetics can be used in endodontic treatment especially for patients with high prediction of postoperative pain

[ in-vitro comparative study of sealing ability of pro root MTA and Portland cement in furcation perforations]

Statement of problem: Root perforation is a procedural error that can have a profound effect on treatment prognosis. Treatment prognosis is dependent on the prevention or the treatment of bacterial infection at the perforation site. Therefore, using a biocompatible material to completely seal the perforation is of paramount importance

Purpose: The purpose of this study was to evaluate and compare the ability of Pro Root MTA and Portland cement to seal furcal perforations in the extracted human molar using dye penetration

Materials and Method: In this experimental in vitro study, 70 human permanent mandibular molars with well developed, non-fused, minimum caries and without anomalies were used. Access openings and furcation perforations were prepared in the pulp chamber floor. Ten teeth were assigned as controls and divided into two groups of five teeth each as positive and negative control. The positive group was accessed and perforated similar to the experimental group while the negative controls were not prepared. The remained 60 teeth were divided into two groups of 30 teeth each. Group A1 was repaired with Pro Root MTA and group A2 was repaired with Portland cement. The teeth were submerged in Indian ink for 4 days. Finally, the samples were sectioned and evaluated for linear dye penetration at 6x magnification and then the data were statistically analyzed by Mann-Whitney test

Results: The result showed that the sealability of Pro Root MTA and Portland cement in furcation perforations was not statistically different [ p >0.05]

Conclusion: In accordance with high expenses of Pro Root MTA and the same ability of Portland cement and Pro Root MTA in sealing of furcation perforation, the Portland cement could be a good alternative for Pro Root MTA for this purpose

[Comparison of three intra-canal irrigants effect on flare-up following treatment of necrotic teeth]

Acute pain and swelling following root canal therapy is considered as flare up. Pushing the infectious debris to the periapical region. Inadequate chemical and mechanical cleaning are the reasons for inflammation of this area. Microorganisms are the major causative agents of acute peri-radicular inflammation. Adequate and appropriate irrigation of the canal removes the intra-canal microorganisms, debris and infected agents from the canal space and may decrease pain and swelling. On the other hand, caustic effect of intra-canal irrigants may cause acute inflammation in the peri-radicular tissue. The aim of this study was to compare the effect of three intra-canal irrigants on the incidence of flare-up following root canal therapy of the teeth with necrotic pulp. In this clinical trial study, 225 patients with molar nectrotic pulp and peri-radiocular lesion were selected and randomly divided into three groups, 75 in each, Protaper Rotary files were used for preparing the canals and 2.5% sodium hypochlorite, 0.2% Chlorhexidine gluconate or saline were used for irrigation of the canals in each group respectively. Then, they were filled by lateral condensation technique. Questionnaires were given to the patients, asking for the level of their pain and swelling. The patients were followed for 48 hours. The data were statistically analyzed, using 'Chi-square, Mann-Whitney and Kruskal-Wallis tests. The results of this study showed no significant difference between irrigant solutions in the incidence of flare-up after endodontic treatment. Our clinical research indicated that the type of irrigating solution used makes little difference in the incidence of postoperative flare-up. It is difficult to attribute flare-up incidence specifically to the use for any particular irrigant

in vitro evaluation of human salvia penetration in obturated root canals with different pairs of root canal filling materials

Gutta-percha presents no adhesion to the tooth structure and sealers. Ideally, it should be replaced by a material that offers better sealing in the entire length of the root canal. The aim of this study was to compare the coronal microleakage of the root canal filled with different pairs of Gutta-percha [GP], Resilon, Epiphany and AH26. For this study, 130 mandibular premolars were chosen. After decoronation and preparation of the root canals of the teeth, they were divided into four experimental groups with 30 teeth each and 2 control groups. Group one was obturated with GP and AH26 sealer, group two with GP and Epiphany sealer, group three with Resilon tips and Epiphany sealer, and group four with Resilon tips and AH26 sealer. All the groups were obturated, using cold lateral condensation. Micro-leakage was tested using a two-chamber bacterial method. The data were subjected to statistical analysis, using a Kaplan-Meier test. The bacterial microleakage test showed no significant difference between groups [p=0.1718]. It is concluded that, in vitro, the epiphany obturation system is as good as gutta-percha sealed with AH26 when compared over 90 days of salvia storage

[Antimicrobial effect of NaoCl, hydrated Ca[OH2], thyme oil and normal saline as irrigating solutions on black pigmented and strep viridance]

Introduction: Bacteria and their by-products are the main cause of pulpal and periapical diseases. Complete debridment and disinfection of the root canal is essential in order to sustain the long term successful results following root canal therapy. This study aims at comparing the antibacterial effect of NaoCl, Thyme oil, Hydrated Calcium Oxide and Normal Saline on selected bacteria isolated from infected root canals

Materials and Methods: Bacteria were collected from 25 infected root canals of patients who had not received antibiotics. The bacteria were collected in the tubes and transfered for bacteriologic examination. Streptococcous viridance and black Pigmented Bacteroid groups were detected by specific bacteriological examination. The experimental solutions were serially diluted 8-folds in saline. A certain volume of bacteria was added to each diluted solution. After 1, 5 and 15 minutes, the solution of each tube was poled onto 3% sheep blood agar plates and incubated at 37°c for 48 hours. The grown colonies were counted and the results were recorded

Results: The results of this study showed a significant antibacterial effect of thyme oil, hydrated calcium hydroxide and sodium hypocholorite on selected bacteria even in low concentration. Normal saline did not show any antibacterial effect

Conclusion: These findings recommended further studies on other aspects such as tissue toxicity, tissue solving and biocompatibility properties of these solutions to be applied for clinical use