Micro-organisms are the primary causative agents of endodontic infections. Phenotype based procedures for bacterial identification has certain drawbacks especially, when investigating the microbiota of root-filled teeth. Thus, more sensitive methods like Polymerase chain reaction (PCR) can provide results that are more accurate and reliable for the microbial prevalence in the root filled teeth.
In this study, we have investigated twenty symptomatic root-filled teeth with chronic apical periodontitis for the prevalence of Enterococcus faecalis and Candida albicans in the root filled teeth associated with symptomatic cases with or without periradicular lesions.
Materials and Methods:
Microbiological samples were taken from the canals immediately after removal of previous gutta percha cones using aseptic techniques. After removal of root canal filling, samples were obtained with paper points placed in the canal. Paper points were transferred to a cryotube containing “Tris EDTA” buffer and immediately frozen at −20°C.
By PCR amplification of the samples using taxon specific primers, E. faecalis was found to be prevalent species, detected in 65% of the cases and C. albicans was detected in 35% of cases.
The results of the study shows that geographical influence and dietary factors might have some role to play in the prevalence of the species like C. albicans and presence of E. faecalis confirming the assertion of previous culture-dependent and independent approaches for the microbiological survey of root filled teeth.
Candida albicans; Enterococcus faecalis; polymerase chain reaction; root filled teeth
To determine the antibacterial effect of photodynamic Therapy on Enterococcus faecalis (E. faecalis) biofilms in experimentally infected human root canals in primary infections and endodontic retreatments.
One hundred and sixty single-rooted extracted teeth with one root canal were prepared using ProTaper instruments. Seventy specimens were left without root canal filling and autoclaved. The root canals of another 70 specimens were filled with Thermafil and AH Plus and the root canal fillings were removed after 24 hours using ProTaper D files and plasma sterilized. The specimens were infected with a clinical isolate of E. faecalis for 72 hours. Samples were taken using sterile paper points to determine the presence of E. faecalis in the root canals. The specimens were randomly divided into groups according to their treatment with 20 teeth each and a control. In the PDT group the teeth were treated using PDT, consisting of the photosensitizer toluidine blue and the PDT light source at 635 nm. In the NaOCl (sodium hypochlorite) group the root canals were rinsed with 10 mL of 3% NaOCl. In the NaOCl-PDT group the root canals were rinsed with 10 mL of 3% of sodium hypochlorite and then treated with PDT. Samples were taken after treatments using sterile paper points. Additionally, remaining root canal filling material was recovered from the root canal walls. Survival fractions of the samples were calculated by counting colony-forming units. A one-way analysis of variance (ANOVA) was applied to the data to assess the effect of different treatment techniques.
Antimicrobial treatment of root canals caused a significant reduction of bacterial load in all groups. NaOCl irrigation eliminated E. faecalis most effectively. PDT alone was less effective compared to NaOCl irrigation and the combination of NaOCl irrigation and PDT. CFU levels recovered from the filling material after NaOCl irrigation of the root canals were 10fold higher compared to PDT and the combination of NaOCl irrigation and PDT.
Photodynamic therapy killed E. faecalis in experimental primary endodontic infections and retreated human root canals. PDT is an effective supplement in root canal disinfection, especially in endodontic retreatments.
Photodynamic therapy; PDT; Photoactivated chemotherapy; Phototherapy; Laser; Root canal disinfection; Endodontic infection; Enterococcus faecalis
Aim: The aim of this study was to determine the frequency of two important pathogenic microorganisms associated with endodontic infections, Enterococcus faecalis and Candida albicans, in root canal samples from patients with necrotic pulps or failed canal therapy by polymerase chain reaction method.
Method: Microbial samples were obtained from 117 teeth with necrotic pulp tissues and 114 teeth with failed endodontic treatment.
Results: E.faecalis were identified in 16% of the necrotic and 10% of the retreated root canal infections by PCR. C.albicans genome were identified in 20% and 11% of the necrotic and retreated root canal infections, respectively, by PCR. The frequencies of microbiota were not statistically different between necrotic and retreatment groups (p > 0.05, chi squared test).
Conclusions: PCR analysis of teeth with periapical lesions revealed that E.faecalis was found in fewer patients than in previous studies. The C.albicans prevelance was consistent with previous reports. No statistical difference was found between primary and secondary root canal infections for C.albicans or E.faecalis.
Key words:Primary root canal infection, secondary root canal infection, E.faecalis, C.albicans.
This study aimed to assess the quality of root fillings, coronal restorations, complications of all root-filled teeth and their association with apical periodontitis (AP) detected by cone-beam computed tomography (CBCT) images from an adult Turkish subpopulation.
Material and Methods
The sample for this study consisted of 242 patients (aging from 15 to 72 years) with 522 endodontically treated teeth that were assessed for technical quality of the root canal filling and periapical status of the teeth. Additionally, the apical status of each root-filled tooth was assessed according to the gender, dental arch, tooth type and age classification, undetected canals, instrument fracture, root fracture, apical resorption, apical lesion, furcation lesion and type and quality of the coronal structure. Statistical analysis was performed using percentages and chi-square test.
The success rate of the root canal treatment was of 54.4%. The success rates of adequate and inadequate root canal treatment were not significantly different (p>0.05). Apical periodontitis was found in 228 (45.6%) teeth treated for root canals. Higher prevalence of AP was found in patients aging from 20 to 29 years [64 (27%) teeth] and in anterior (canines and incisors) teeth [97 (41%) teeth].
The technical quality of root canal filling performed by dental practitioners in a Turkish subpopulation was consistent with a high prevalence of AP. The probable reasons for this failure are multifactorial, and there may be a need for improved undergraduate education and postgraduate courses to improve the clinical skills of dental practitioners in endodontics.
Cone-beam computed tomography; Root canal; Apical periodontitis
Statement of Problem: The knowledge of the pulp anatomy plays an important role in the success of endodontic treatments.
Purpose: The aim of this study was to determine the root and canal morphology of the mandibular second molar teeth in an Iranian population.
Material and Methods: One hundred intact human mandibular second molars were collected. The teeth were examined visually and the number of their roots were recorded. The teeth were covered using of lacquer. Access cavities were prepared and the pulp tissue was dissolved by sodium hypochlorite. The apices were covered with the glue and the root canals were injected with the methylene blue and were decalcified with 10% nitric acid, dehydrated with ascending concentrations of alcohol and rendered clear by immersion in methyl salicylate. The following remarks were evaluated: (i) number of root canals per tooth; (ii) number of canals per root; (iii) canal configuration in each root.
Results: Of 100 examined teeth; 6% had one root, 89% had two roots, 2% had three roots and 3% had C-shaped roots. The teeth were classified based on the number of canals: 3 % had single canal, 6 % two canals, 54% three canals, 34% four canals, whilst 3 % had C-shaped roots. Based on the Vertucci classification, the most prevalent canal configuration in the mesial root was type II and in the distal root was type I.
: Iranian mandibular second molar teeth exhibit features which are similar to the average Jordanian, Caucasian and Burmese root and canal morphology.
Canal Morphology; Mandibular Second Molar; Clearing; Iranian Population
Despite numerous studies on the prevalence of apical periodontitis (AP) and endodontic treatment in diverse geographical populations, there are currently no data on the prevalence of these conditions in populations of adults native to Kosovo. Therefore, little is known about how widespread these conditions are, and whether there is any correlation between root canal treatment and AP. The purpose of our research was to address this anomaly by investigating AP and endodontic treatment in an adult Kosovar population based on radiographic examination.
The sample used for this study consisted of randomly selected individuals referred to the University Dentistry Clinical Center of Kosovo in the years 2006-2007. Orthopantomographs of 193 patients were evaluated. The periapical status of all teeth (with the exception of third molars) was examined according to Ørstavik's Periapical Index. The quality of the root canal filling was rated as 'adequate' or 'inadequate' based on whether all canals were filled, the depth of fill relative to the radiographic apex and the quality of compaction (absence/presence of voids). Data were analyzed statistically using the Chi-square test and calculation of odds ratios.
Out of 4131 examined teeth, the prevalence of apical periodontitis (AP) and endodontic treatment was 12.3% and 2.3%, respectively. Of 95 endodontically-treated teeth, 46.3% were associated with AP. The prevalence of AP increased with age. The prevalence in subjects aged over 60 years old (20.2%) was higher than in other age groups. A statistically significant difference was found for the frequency of endodontically-treated teeth associated with AP in the 40-49 year age group (P < 0.001). Of some concern was the discovery that only 30.5% of the endodontically-treated teeth examined met the criteria of an acceptable root canal filling. Inadequately root-filled teeth were associated with an increased AP risk.
The prevalence of AP and the frequency of endodontically-treated teeth with AP in this Kosovar population are higher than those found in other countries. Inadequate root canal fillings were associated with an increased prevalence of AP.
During post preparation, the root canal is exposed to the oral cavity, and endodontic
treatment may fail because of coronal leakage, bacterial infection and sealing
inability of the luting cement.
this study quantified the interfacial continuity produced with conventional
dual-cure and self-adhesive resin cements in the cervical (C), medium (M) and
apical (A) thirds of the root.
Material and methods
Forty single-rooted human teeth were restored using Reforpost # 01 conical
glass-fiber posts and different materials (N=10 per group): group
AC=Adper™ ScotchBond™ Multi-purpose Plus + AllCem; group ARC=Adper™
ScotchBond™ Multi-purpose Plus + RelyX ARC; group U100=RelyX U100; and group
MXC=Maxcem Elite. After being kept in 100% humidity at 37ºC for 72 hours, the
samples were sectioned parallel to their longitudinal axis and positive epoxy
resin replicas were made. The scanning electron micrographs of each third section
of the teeth were combined using Image Analyst software and measured with
AutoCAD-2002. We obtained percentage values of the interfacial continuity.
Interfacial continuity was similar in the apical, medium and cervical thirds of
the roots within the groups (Friedman test, p>0.05). Comparison of the
different cements in a same root third showed that interfacial continuity was
lower in MXC (C=45.5%; M=48.5%; A=47.3%) than in AC (C=85.9%, M=81.8% and
A=76.0%), ARC (C=83.8%, M=82.4% and A=75.0%) and U100 (C=84.1%, M=82.4% and
A=77.3%) (Kruskal-Wallis test, p<0.05).
Allcem, Rely X ARC and U100 provide the best cementation; cementation was similar
among root portions; in practical terms, U100 is the best resin because it
combines good cementation and easy application and none of the cements provides
complete interfacial continuity.
Post and core technique; Resin cements; Dental marginal adaptation; Dentin-bonding agents
To evaluate the anti-microbial effects of photodynamic therapy (PDT) on infected human teeth ex vivo.
Materials and Methods
Fifty-two freshly extracted teeth with pulpal necrosis and associated periradicular radiolucencies were obtained from 34 subjects. Twenty-six teeth with 49 canals received chemomechanical debridement (CMD) with 6% NaOCl and twenty-six teeth with 52 canals received CMD plus PDT. For PDT, root canal systems were incubated with methylene blue (MB) at concentration of 50 µg/ml for 5 minutes followed by exposure to red light at 665 nm with an energy fluence of 30 J/cm2. The contents of root canals were sampled by flushing the canals at baseline and following CMD alone or CMD+PDT and were serially diluted and cultured on blood agar. Survival fractions were calculated by counting colony-forming units (CFU). Partial characterization of root canal species at baseline and following CMD alone or CMD+PDT was performed using DNA probes to a panel of 39 endodontic species in the checkerboard assay.
The Mantel-Haenszel chi-square test for treatment effects demonstrated the better performance of CMD+PDT over CMD (P=0.026). CMD+PDT significantly reduced the frequency of positive canals relative to CMD alone (P=0.0003). Following CMD+PDT, 45 of 52 canals (86.5%) had no CFU as compared to 24 of 49 canals (49%) treated with CMD (canal flush samples). The CFU reductions were similar when teeth or canals were treated as independent entities. Post-treatment detection levels for all species were markedly lower for canals treated by CMD+PDT than were for those treated by CMD alone. Bacterial species within dentinal tubules were detected in 17/22 (77.3%) and 15/29 (51.7%) of canals in the CMD and CMD+PDT group, respectively (P= 0.034).
Data indicate that PDT significantly reduces residual bacteria within the root canal system, and that PDT, if further enhanced by technical improvements, holds substantial promise as an adjunct to CMD.
Photodynamic therapy; methylene blue; endodontic disinfection; ex vivo
To investigate the prevalence of Enterococcus faecalis in saliva and filled root canals of patients requiring endodontic retreatment for apical periodontitis. Patients with apical periodontitis who were referred for endodontic retreatment were examined. The type and quality of the restoration, symptoms, quality of obturation were recorded. During retreatment, an oral rinse sample and root canal sample were cultured using brain-heart infusion agar and bile esculinazide agar to select for E. faecalis. The 16S rRNA technique was used to identify E. faecalis. A total of 32 women and 22 men (mean age: 38 years; s.d.: 11 years) and 58 teeth were studied. The prevalence of E. faecalis was 19% in the saliva and 38% in the root canals. The odds that root canals harbored E. faecalis were increased if the saliva habored this bacterium (odds ratio=9.7; 95% confidence interval=1.8–51.6; P<0.05). Teeth with unsatisfactory root obturation had more cultivable bacterial species in root canals than teeth with satisfactory root obturation (P<0.05). E. faecalis is more common in root canals of teeth with apical periodontitis than in saliva. The prevalence of E. faecalis in root canals is associated with the presence of E. faecalis in saliva.
apical periodontitis; endodontic treatment; Enterococcus faecalis; saliva; 16S rRNA
Background and aims
The aim of this study was to determine the microorganisms prevalent in the necrotic dental pulp and root canals of unsuccessfully treated teeth.
Materials and methods
The present study was conducted on 150 single-rooted teeth of patients referring to a dental clinic. Sampling was performed by placing a sterile paper point in the canal for 60 s. Bacterial samples were evaluated by a microbiological technique specific for anaerobic species, used for isolation and identification of sampled strains.
From the 150 samples taken, 101 were from necrotic pulps (primary infection) and 49 were from the teeth with an unsuccessful endodontic treatment (secondary infection).
Enterococcus faecalis was a prevalent species in the failed root canals evaluated.
Endodontic therapy; Enterococcus faecalis; failure
To investigate the expression of matrix metalloproteinases (MMPs) in apical periodontitis and during the periapical healing phase following root canal treatment.
Apical periodontitis was induced in dog teeth and root canal treatment was performed in a single visit or using an additional calcium hydroxide root canal dressing. One hundred and eighty days following treatment the presence of inflammation was examined and tissues were stained to detect bacteria. Bacterial status was correlated to the degree of tissue organization, and to further investigate molecules involved in this process, tissues were stained for MMP-1, MMP-2, MMP-8, and MMP-9. Data were analyzed using one-way ANOVA followed by Tukey test or Kruskal-Wallis followed by Dunn.
Teeth with apical periodontitis that had root canal therapy performed in a single visit presented an intense inflammatory cell infiltrate. Periapical tissue was extremely disorganized, and this was correlated with the presence of bacteria. Higher MMP expression was evident, similar to teeth with untreated apical periodontitis. In contrast, teeth with apical periodontitis submitted to root canal treatment using calcium hydroxide presented a lower inflammatory cell infiltrate. This group had a moderately organized connective tissue, a lower prevalence of bacteria, and a lower number of MMP-positive cells, similar to healthy teeth submitted to treatment.
Teeth treated with calcium hydroxide root canal dressing exhibited a lower percentage of bacterial contamination, a lower MMP expression, and a more organized ECM, unlike those treated in a single visit. This suggests that calcium hydroxide may be beneficial in tissue repair processes.
apical periodontitis; root canal treatment; single visit; calcium hydroxide; matrix metalloproteinases
For successful endodontic treatment, it's imperative to locate and obturate all root canals. As concluded by Ingle, the major cause for failure of root canal therapy is in ability to recognize all theexisting canals and subsequent failure in their obturation.
To analyze the canal configuration of the mesio-buccal root of maxillary first permanent molar teeth.
Materials and Methods:
A total of 30 recently extracted human permanent maxillary first molars were collected and stored in a container with 5% Sodium Chloride solution for four days. Teeth with open apices, external resorption, improperly formed roots and teeth with previous restorations were excluded. Using the dental modeling wax, teeth were arranged in a ‘U’ shaped arch with roots embedded inside the wax and occlusal surface remaining free. 10 teeth were arranged in each arch and three such sample plates were prepared. Flat surface of the base encasing enabled the plate to be mounted on flat plastic bite plate. With bite plate roughly centered in the focal trough area Axial, Coronal and Sagittal section Cone-Beam Computed Tomography (CBCT) images were taken with Kodak 9000 Extra-oral Imaging System. Images displayed on a monitor were inspected by two endodontists using Kodak Dental Imaging Software 3D Module V2.2.
When the data was observed, it was found that 24 teeth out of total 30 teeth examined showed some variation (i.e. possible additional canal) along the length of the mesio-buccal root canal. Out of these 24 teeth, 13 showed presence of additional canal at coronal third, 7 showed presence of additional canal at middle third and four showed presence of additional canal in apical third level. Percentage analysis was done as there was no group comparison to be done.
Cone-Beam Volumetric Tomography (CBVT) evaluation positively identified the variations in mesio-buccal canal in 80% of samples. Out of these, 54.16% were in coronal 3rd, 29.16% in middle 3rd and 16.66% were in apical 3rd.
Within the limitations of this study, it can be concluded that- (1) more than half of maxillary first molars have four canals and (2) most of the additional canals were located in the MBR and CBVT is a good diagnostic tool to help diagnose these additional canals. Further investigations using larger sample sizes would be helpful.
Cone-beam computed tomography; cone beam projection geometry; MB2 canal; root canal system
Background and objective
Bacterial invasion into pulps of primary teeth can lead to infection and premature tooth loss in children. This pilot study aimed to explore whether the microbiota of carious exposures of dental pulps resembles that of carious dentin or that of infected root canals.
Children with severe early childhood caries were studied. Children were consented and extent of caries, plaque, and gingivitis measured. Bacteria were sampled from carious lesion biofilms and vital carious exposures of pulps, and processed by anaerobic culture. Isolates were characterized from partial sequences of the 16S rRNA gene and identified by comparison with taxa in the Human Oral Microbiome Database (http://www.HOMD.org). The microbiotas of carious lesions and dental pulps were compared using univariate and multivariate approaches.
The microbiota of cariously exposed pulps was similar in composition to that of carious lesion biofilms except that fewer species/taxa were identified from pulps. The major taxa identified belonged to the phyla Firmicutes (mainly streptococci) and Actinobacteria (mainly Actinomyces species). Actinomyces and Selenomonas species were associated with carious lesions whereas Veillonella species, particularly Veillonella dispar was associated with pulps. Other bacteria detected in pulps included Streptococcus mutans, Parascardovia denticolens, Bifidobacterium longum, and several Lactobacillus and Actinomyces species. By principal, component analysis pulp microbiotas grouped together, whereas those in caries biofilms were widely dispersed.
We conclude that the microbiota of cariously exposed vital primary pulps is composed of a subset of species associated with carious lesions. Vital primary pulps had a dominant Firmicutes and Actinobacteria microbiota which contrasts with reports of endodontic infections which can harbor a gram-negative microbiota. The microbiota of exposed primary pulps may provide insight into bacterial species at the forefront of caries invasion in dentinal lesions that can invade into the pulp and the nature of species that need suppressing for successful pulp therapy.
16S rRNA; culture; Streptococcus mutans; Parascardovia
To clinically evaluate the dimension of the more apical extent of the root canal after appropriate preflaring in the case of primary treatment and retreatment with and without the presence of periapical radiolucency, 392 single-rooted teeth with only one canal were evaluated during endodontic therapy. The canals were divided in two groups depending on the presence or absence of periapical radiolucency. After preflaring of the root canal the size of the root canal terminus (apical canal dimension) was gauged with hand-held Light Speed LS1 files inserted at the estimated working length and established with the use of an electronic apex locator. The dimension recorded in the computer database was represented by the largest instrument able to reach the electronically established working length. The differences between the treatment groups were assessed using the Mann-Whitney U test and the significance level was set at P < 0.05. Teeth with lesions had a significantly greater diameter in the apical region than teeth without lesions (P < 0.001). The dimension of the apical portion of the root canal is larger in the case of periapical radiolucency. This involves verifying this parameter in order to use the correct sized instruments and to obtain an efficient cutting action at the apical level.
To determine the prevalence of apical periodontitis and assess the quality of endodontic fillings in the population of the city of Zagreb, Croatia.
A total of 1462 orthopantomograms from new patients at 6 different dental practices was analyzed during 2006 and 2007. The presence of periapical lesions was determined by using the periapical index score (PAI). The quality of endodontic fillings was assessed according to the filling length and homogeinicity. Data were analyzed using t test and ANOVA with Scheffe post-hoc test.
There were 75.9% of participants with endodontically treated teeth and 8.5% of all teeth were endodontically treated. Only 34.2% of endodontically treated roots had adequate root canal filling length, while 36.2% of root canal fillings had homogenous appearance. From the total number of teeth with intracanal post, 17.5% had no visible root canal filling. Using PAI 3 as a threshold value for apical periodontitis, periapical lesions were detected in 8.5% of teeth. Adequate quality of root canal fillings was associated with a lower prevalence of periapical lesions.
We found a large proportion of endodontically treated teeth with apical periodontitis and a correlation between the quality of endodontic filling and the prevalence of periapical lesions. This all suggests that it is necessary to improve the quality of endodontic treatment in order to reduce the incidence and prevalence of apical periodontitis.
The purpose of this study was to evaluate the distribution of microorganisms in the root canal system (RCS) and periapical lesions of dogs' teeth after rotary instrumentation and placement of different calcium hydroxide [Ca(OHy-based intracanal dressings.
MATERIALS AND METHODS:
Chronic periapical lesions were experimentally induced in 80 premolar roots of four dogs. Instrumentation was undertaken using the ProFile rotary system and irrigation with 5.25% sodium hypochlorite. The following Ca(OH)2-based pastes were applied for 21 days: group 1 - Calen (n=18); group 2 - Calen+CPMC (n=20); group 3 - Ca(OH2 p.a. + anaesthetic solution (n=16) and group 4 - Ca(OH2 p.a.+ 2% chlorhexidine digluconate (n=18). Eight root canals without endodontic treatment constituted the control group. Histological sections were obtained and stained with Brown & Brenn staining technique to evaluate the presence of microorganisms in the main root canal, ramifications of the apical delta and secondary canals, apical cementoplasts, dentinal tubules, areas of cemental resorption and periapical lesions. The results were analyzed statistically by the Mann-Whitney U test (p<0.05).
The control group showed the highest prevalence of microorganisms in all sites evaluated. Gram-positive cocci, bacilli and filaments were the most frequent morphotypes. Similar microbial distribution patterns in the RCS and areas of cementum resorption were observed in all groups (p>0.05). The percentage of RCS sites containing microorganisms in groups 1, 2, 3, 4 and control were: 67.6%, 62.5%, 78.2%, 62.0% and 87.6%, respectively.
In conclusion, the histomicrobiological analysis showed that the rotary instrumentation and the different calcium hydroxide pastes employed did not effectively eliminate the infection from the RCS and periapical lesions. However, several bacteria seen in the histological sections were probably dead or were inactivated by the biomechanical preparation and calcium hydroxide-based intracanal dressing.
Calcium hydroxide pastes; Endodontic infection; Periapical lesions; Root canal therapy
Aim: A cross-sectional radiographic orthopantomogram (OPG) survey was done to determine the prevalence of apical periodontitis (AP) in root canal–treated teeth in a selected population, and to evaluate the influence of the coronal restorations (CR) and root canal fillings on the periapical status.
Materials and methods: A total of 250 OPGs were evaluated out of which root canal treatment (RCT) had been performed in 438 teeth which was taken as the sample size.
Statistical analysis used: Chi-square test, odds ratio and p-values were recorded.
Results: The results showed that 53.1% of the endodontically treated teeth presented with AP radiographically. Incidence of AP among teeth with acceptable RCT (32.3%) was significantly lower than those suffering from unacceptable RCT (92.7%). Moreover, adequate CR demonstrated a significantly better periapical status (83.2%) compared to teeth with inadequate CR (37.2%). Also, the combination of adequate CR and adequate root filling resulted in significantly reduced incidence of AP (21.6%) compared to the presence of AP (97%) when both parameters scored as inadequate.
Conclusion: Results hence demonstrated that a well-performed RCT and well-sealing CR are both essential for the overall success of endodontic treatment. Therefore, a considerable improvement in the quality of RCT and CR in general dental practice is required to promote oral/periapical health.
How to cite this article: Khullar P, Raisingani D, Gupta S, Khatri RK. A Survey Report on Effect of Root Canal Fillings and Coronal Restorations on the Periapical Status of Endodontically Treated Teeth in a Selected Group of Population. Int J Clin Pediatr Dent 2013;6(2):89-94.
Apical periodontitis; Endodontic treatment; Coronal restoration; Root fillings
This study performed barcoded multiplex pyrosequencing with a 454 FLX instrument to compare the microbiota of dental root canal infections associated with acute (symptomatic) or chronic (asymptomatic) apical periodontitis. Analysis of samples from 9 acute abscesses and 8 chronic infections yielded partial 16S rRNA gene sequences that were taxonomically classified into 916 bacterial species-level operational taxonomic units (OTUs) (at 3% divergence) belonging to 67 genera and 13 phyla. The most abundant phyla in acute infections were Firmicutes (52%), Fusobacteria (17%) and Bacteroidetes (13%), while in chronic infections the dominant were Firmicutes (59%), Bacteroidetes (14%) and Actinobacteria (10%). Members of Fusobacteria were much more prevalent in acute (89%) than in chronic cases (50%). The most abundant/prevalent genera in acute infections were Fusobacterium and Parvimonas. Twenty genera were exclusively detected in acute infections and 18 in chronic infections. Only 18% (n = 165) of the OTUs at 3% divergence were shared by acute and chronic infections. Diversity and richness estimators revealed that acute infections were significantly more diverse than chronic infections. Although a high interindividual variation in bacterial communities was observed, many samples tended to group together according to the type of infection (acute or chronic). This study is one of the most comprehensive in-deep comparisons of the microbiota associated with acute and chronic dental root canal infections and highlights the role of diverse polymicrobial communities as the unit of pathogenicity in acute infections. The overall diversity of endodontic infections as revealed by the pyrosequencing technique was much higher than previously reported for endodontic infections.
Bacterial infection of tooth pulp can progress into periapical diseases. Root canal treatment has been established as the best treatment. In cases of failure, nonsurgical retreatment of teeth is preferred to surgical procedure and extraction.
MATERIALS AND METHODS
In this historical cohort study, 104 permanent teeth with apical lesion were treated during 2002-2008. All teeth showed radiographic evidence of periapical lesion varying in size from 1 to >10mm. A total of 55 teeth were treated with initial root canal treatment and 49 teeth required retreatment. Patients were recalled up to ≈7 years. All radiographs were taken by RSV MAC digital imaging set and long cone technique. The presence/absence of signs and symptoms and periapical index scores (PAI) were used for measuring outcome. Teeth were classified as healed (clinical/radiographic absence of signs and symptoms) or diseased (clinical/radiographic presence of signs and symptoms). The data were statistically analyzed using student t-test and Pearson chi-square or fisher’s exact test.
The rate of complete healing for teeth with initial treatment was 89.7%, and for retreatment group was 85.7%; there was no significant difference. Size of lesions did not significantly affect the treatment outcomes. Success of tooth treatment did not reveal significant correlation with gender and number of roots.
Orthograde endodontic treatment/retreatment demonstrates favorable outcomes. Thus, nonsurgical endodontic treatment/retreatment should be considered as the first choice in teeth with large periapical lesion.
Endodontics; Periapical Disease; Retreatment; Root Canal Therapy; Treatment Outcome
The aim of this study was to investigate in vivo microorganisms detected in root-filled teeth with post-treatment apical periodontitis and quantify colony-forming units (CFU) during endodontic retreatment.
Materials and Methods:
Fifteen root-filled teeth had their previous gutta-percha removed and were randomly instrumented before being divided into three groups and medicated with either [Ca(OH)2 + 2% CHX gel], [Ca(OH)2 + 0.9% NaCl] or 2% CHX gel. Samples were taken after removal of gutta-percha (S1), after chemomechanical preparation using 2% CHX gel (S2), and after inter-appointment dressing (S3) for 7 or 14 days later. Cultivable bacteria recovered from infected root canals at the three stages were counted and identified by means of culture and PCR assay (16S rDNA). Quantitative data were statistically analyzed by using Mann-Whitney test in which pairs of groups were compared (P < 0.05).
CFU counts decreased significantly from S1 to S2 (P < 0.05). No significant difference was found between S2 and S3 (P = 0.3093) for all three experimental groups. Chemomechanical preparation and intra-canal dressing promoted significant median reductions of 99.61% and 99.57%, respectively, in the number of bacteria compared to S1 samples. A total of 110 cultivable isolates were recovered by culture technique from 32 different species and 7 different genera. Out of the 13 target species-specific primer of bacteria analyzed, 11 were detected during endodontic retreatment.
The great majority of taxa found in post-treatment samples were Gram-positive bacteria, although Gram-negative bacteria were found by molecular methods. Moreover, our results showed that gutta-percha removal and chemomechanical preparation are effective for root canal disinfection, whereas additional intra-canal dressing did not improve disinfection.
Endodontic failure; endodontic outcome; intra-canal dressing; nonsurgical retreatment; root canal infection
The aim of this study was to determine the prevalence of apical periodontitis and the technical quality of root canal fillings in a Palestinian sub-population.
The panoramic radiographs of 258 patients (142 females, 116 males) attending dental clinics in 2010 were examined to identify the presence of apical lesions associated with any remaining teeth, excluding third molars. The technical quality of root canal fillings was also evaluated by assessing apical extension from the radiographic apex. The panoramic radiographs were taken by a well-trained radiology assistant and evaluated by a radiologist and an endodontist. Statistical analysis was performed with the chi-square test with a significant level set at P < 0.05%.
Of 6482 teeth examined radiographically, 978 (15.1%) had radiographic signs of apical periodontitis (AP). The prevalence of AP was 8.3% in teeth without filled roots and 59.5% (509/855) in root canal-treated teeth. The prevalence of AP and endodontic treatment increased with age and differed significantly (p < 0.05) between males and females. The majority (74.5%) of root canal fillings was performed inadequately, and most (77.2%) inadequate fillings were >2 mm short of the radiographic apex. The presence of AP was correlated significantly with poorly executed root canal fillings (p < 0.05).
The present study found a high prevalence and incidence of AP in association with root-filled teeth. The technical quality of many root canal treatments was unacceptable.
Apical periodontitis; Epidemiology; Radiographic evaluation; Root canal treatment
This study sought to investigate the prevalence of eight oral Treponemas (Treponema denticola, T. amylovorum, T. maltophilum, T. medium, T. pectinovorum, T. socranskii, T. vicentii and T. lecithinolyticum) in teeth with endodontic treatment failure and periapical lesion.
Samples were taken from 40 root canals presenting endodontic failure and periapical lesion. DNA extraction was performed and Nested-PCR technique was used for the detection of Treponema species using specific primers.
Treponemas was detected in 56.5% of the samples analyzed (22/39). Individual root canals yielded a maximum of 6 target Treponema species. T. denticola (30.8%) and T. maltophilum (30.8%) were the most frequently detected species followed by T. medium (20.5%), T. socranskii (20.5%), T. pectinovorum (17.9%) and T. vicentii (17.9%). Positive association was verified between T. denticola and T. maltophilum such as T. medium (P<.05). T. lecithinolyticum was positively associated with intraradicular post (P<.05).
The present study revealed that a wide variety of Treponema species plays a role in persistent/secondary infection turning the root canal microbiota even more complex than previously described by endodontic literature.
Endodontic failure; microbiology; nested-PCR; bacteria; root canal
Statement of Problem: Most failures of root canal treatments are caused by bacteria. Studies showed that the most common cause of endodontic failures were the incomplete obturation of the root canal and the lack of adequate apical seal. Some in-vitro methods are used to estimate sealing quality, generally by measuring microleakage that allows the tracer agent to penetrate the filled canal.
Purpose: Conventional methods of evaluating the seal of endodontically treated teeth are complicated and have some drawbacks. We used copper ion diffusion method to assess the leakage and the results were compared to dye penetration method.
Materials and Method: The crowns of 21 extracted teeth were cut off at the CEJ level. After preparing the canals, the teeth were placed in tubes containing saline. They were divided randomly into 15 experimental cases; 3 positive and 3 negative controls. Positive controls were filled by single cone without sealer while the experimental and the negative control groups were filled by lateral technique. The coronal portion of gutta was removed and 9mm was left. The external surface of each tooth was coated with nail polish. Two millimeters of apical portion was immersed into 9ml of distilled water and 0.3ml of CuSO4 solution was injected into the coronal portion. After 2 days, copper sulfate was measured by an atomic absorption spectrophotometer. The teeth were then immersed in 2% methylene blue for 24 hours, sectioned and the extent of dye penetration was measured by a stereomicroscope.
Results: The maximum and minimum recorded copper ion concentrations for the experimental group were 18.37 and 2.87ppm respectively. The maximum and minimum recorded dye penetrations for the experimental group were 8.5 and 3.5mm respectively. The statistical analysis, adopting paired samples test, showed poor correlation between average recorded results of two methods.
Conclusion: Based on our results, there was no significant correlation between the dye penetration and the copper ion diffusion methods.
Apical Leakage; Copper Diffusion; Dye Penetration; Methylene Blue
This cross-sectional survey determined the dental prevalence of apical periodontitis (AP) in selected Iranian population, and evaluated the influence of the quality of root canal treatment (RCT) and their coronal restorations (CR) on the periapical status.
MATERIALS AND METHODS
A total of 1064 panoramic radiographies were evaluated by two observers during 2009. The quality of RCT i.e. length/density of root fillings and CR in addition to periapical status of endodontically treated teeth were recorded. Their interrelationship was analyzed by Chi-squared, logistic regression and Spearman's rho statistics. Hosmer and Lemeshow tests were used for assessing fitness of logistic regression model and one sample k-s test was used for evaluating of normality of the data.
Our results showed that 527 teeth (52%) of the endodontically treated teeth presented with AP radiographically. The percentages of teeth which fulfilled the criteria of an acceptable RCT or CR radiographically were 42.3 and 62.5 respectively. Incidence of AP among teeth with acceptable RCT (29.1%) was significantly lower than those suffering from unacceptable RCT (68.8%) (P<0.001). Moreover, adequate CR demonstrated a significantly better periapical status (58.6%) compared to teeth with inadequate CR (30.3%) (P<0.001). The incidence of AP ranged from 25.6% (good qualities) to 79.5% (bad qualities) (P<0.001). Cases with both unacceptable RCT/CR were 11 times more likely to have AP than cases with acceptable RCT/CR. The quality of RCT and CR were found to impact the periapical health of endodontically treated teeth.
There are a significant high number of technically unacceptable endodontic and restorative treatments in Iran; therefore considerable efforts are needed to improve the standards of endodontic and restorative treatments.
Apical Periodontitis; Coronal Restoration; Endodontic Outcomes; Epidemiology; Root Fillings
Endodontic infections have been traditionally studied by culture methods, but recent reports showing that over 50% of the oral microbiota is still uncultivable (B. J. Paster et al., J. Bacteriol. 183:3770-3783, 2001) raise the possibility that many endodontic pathogens remain unknown. This study intended to investigate the prevalence of several uncultivated oral phylotypes, as well as newly named species in primary or persistent endodontic infections associated with chronic periradicular diseases. Samples were taken from the root canals of 21 untreated teeth and 22 root-filled teeth, all of them with radiographic evidence of periradicular bone destruction. Genomic DNA was isolated directly from each sample, and 16S rRNA gene-based nested or heminested PCR assays were used to determine the presence of 13 species or phylotypes of bacteria. Species-specific primers had already been validated in the literature or were developed by aligning closely related 16S rRNA gene sequences. Species specificity for each primer pair was confirmed by running PCRs against a panel of several oral bacteria and by sequencing DNA from representative positive samples. All species or phylotypes were detected in at least one case of primary infections. The most prevalent species or phylotypes found in primary infections were Dialister invisus (81%), Synergistes oral clone BA121 (33%), and Olsenella uli (33%). Of the target bacteria, only these three species were detected in persistent infections. Detection of uncultivated phylotypes and newly named species in infected root canals suggests that there are previously unrecognized bacteria that may play a role in the pathogenesis of periradicular diseases.