Bacterial status in root-filled teeth exposed to the oral environment by loss of restoration and fracture or caries - a histobacteriological study of treated cases

Orifice barrier preferences for coronal restoration of root filled teeth by endodontists and other dental practitioners in Australia: A questionnaire survey

OBJECTIVES

To compare the use of orifice barriers (OB) in root-filled teeth (RFT) between specialist endodontic practitioners (SEP) and general and other specialist practitioners (GDP+), and identify common materials, reasons for selection, and techniques.

METHODS

An online survey was distributed to SEP and GDP+ practising in Australia. Demographic and multiple-choice questions relating to material selection and technique choices were asked to evaluate and relate usage patterns to practising and training backgrounds. Fisher's exact tests were undertaken to compare categorical variables across practitioner groups. Significance level was set at p<.05.

RESULTS

There were 457 eligible responses: 393(86%) GDP+ and 64(14%) SEP. Of 429 reporting endodontically treating or restoring teeth, 317(73.9%) placed OB; preferred depth of root filling removal by most (91.8%) was ≤ 2 mm, with more SEP preferring 2 mm than GDP+(p=.02). Preferred materials for OB were conventional and resin-modified GIC (GIC), resin composite materials (RC), Cavit™ and zinc polycarboxylate cement (ZPC). 'Ease of use' was a common reason among all practitioners for GIC and RC. Significantly more SEP(p<.001) chose ZPC in all teeth and more commonly because of 'Ease of use' for both posterior (p<.001) and anterior (p=.002) teeth. All ZPC-using SEP preferred using a paste-filler/lentulo spiral, significantly more than GDP+ for posterior (p<.001) and anterior (p=.002) teeth. Cavit™ was often chosen for 'Sealing ability'.

CONCLUSIONS

OB were widely placed by dental practitioners in Australia, with a small group of materials selected, most commonly for ease of use or sealing ability. The findings of this study suggest that further research should be undertaken to investigate the relative performance of these materials as OB and to inform the clinician's choices when restoring RFT.

In vitro bacterial penetration and dissemination through dentinal tubules in roots filled with calcium silicate-based cements

The aim of this study was to assess whether calcium silicate root fillings prevent bacterial penetration and to determine how bacteria penetrate roots. Extracted single-rooted, single-canal human teeth were decoronated, prepared and filled with ProRootMTA or Biodentine (n = 12 each). Positive and negative (n = 2 each) controls were not filled. A two-chamber model was used with Streptococcus gordonii. The lower compartment was evaluated for turbidity over 150 days. Roots were split and examined for bacteria via SEM. The chi-squared test was used for comparisons (α = 0.05). Experimental groups had bacteria in their coronal thirds. Tubules contained bacteria in 90.9% and 91.7% of areas examined in the Biodentine and ProRootMTA groups, respectively, with no significant difference (p = 0.914). Experimental and negative roots had no turbidity with no significant difference between Biodentine and ProRootMTA (p = 1.000). Positive controls had turbidity. Bacteria penetrate roots via dentine tubules of root-filled teeth. Biodentine was comparable to ProRoot MTA.

Time assessment for final restoration of endodontically treated teeth in a university clinic setting: An observational study

Background

The aim was to quantify the time elapsed between tooth reconstruction and the end of endodontic treatment, and to assess differences according to sex, age, and tooth group.

Material and Methods

A retrospective study was conducted with patient clinical records. Data relating to patient characteristics, treated teeth, endodontic treatment, and subsequent restorative treatment were recorded.

Results

For this study, 355 endodontically treated teeth by undergraduate students during 2019 were included. 24 teeth (6.76 %) were not restored, more direct (86.4 %) than indirect (13.6 %) restorations were performed, and the most frequent type of restoration was complex filling. The mean elapsed time from endodontic completion to direct restoration was 7 days, with a minimum of 0 and a maximum of 90 days. For indirect restorations the mean elapsed time was 21 days.

Conclusions

The median elapsed time for endodontic tooth reconstruction was 7 days (IQR = 7), however, treatment should not be considered completed until the tooth has been properly restored. In cases where an indirect restoration was also necessary, the median elapsed time was higher (21 days; IQR = 31.5).

Biological considerations of dental materials as orifice barriers for restoring root-filled teeth

There is ample published literature regarding the technical aspects of restoring root-filled teeth, but little concerning the biological impacts, consequences, and criteria for the selection of direct restorative materials following endodontic treatment. The provision of an effective coronal seal in addition to a sound root filling is known to be important in the prevention of root canal infection. This review seeks to explore the evidence concerning the selection of dental materials in the restoration of root-filled teeth, specifically with a close examination of the properties of commonly used materials as orifice barriers. © 2023 Australian Dental Association.

Periapical status transitions in teeth with posts versus without posts: a retrospective longitudinal radiographic study

OBJECTIVES

The aim of this study was to compare periapical status transitions in teeth after post placement compared with other post-endodontic treatments in root-filled teeth.

MATERIAL AND METHODS

This retrospective longitudinal radiographic study included radiographs of 284 patients with root filled and restored teeth with composite fillings (Endo-fill group, n = 100), crown or fixed prosthesis (Endo-crown group, n = 82) or post and core restorations (Endo-post group, n = 102). All post and core restorations were made of gold alloy. The radiographs taken at the end of endodontic treatment, at the end of post-endodontic treatment and at least 8 months after post-endodontic treatment were evaluated. Post-operative periapical status was assessed according to the periapical index (PAI) and all teeth included in the study had no apical periodontitis preoperatively. Multi-state Markov analysis was used to assess periapical status transitions among the treatment groups.

RESULTS

Of 284 root-filled teeth without apical periodontitis at baseline, 7.7% developed clear apical pathology within a minimum of 8 months observational period. In the Endo-post group 11 (10.78%) teeth transited from Healthy (PAI 1) to Disease (PAI 2-4) state compared with eight (9.75%) in the Endo-crown group and four (4%) in the Endo-fill group. The transition probabilities from Healthy (PAI 1) to Mild diseased (PAI 2) were 17.5% in the Endo-post group, 13.1% in the Endo-crown group and 5.3% in the Endo-fill group. Multivariate analysis showed that teeth in the Endo-fill group had 60% lower hazard to transit from Healthy (PAI 1) to Mild diseased (PAI 2) state [HR 0.40; 95% CI 0.12, 0.94]. A period exceeding 8 months between the end of the endodontic treatment and prosthetic treatment significantly increased the hazard of disease progression by three times compared with a period of ≤8 months [HR 3.16; 95% CI 1.06, 9.42].

CONCLUSIONS

Teeth without radiographic lesions at baseline and restored with posts had higher hazard to transit from healthy to diseased periapical status compared with teeth restored with composite restorations. Controlled clinical trials with longer follow-up periods are needed to validate these findings.

Irrigating Solutions and Activation Methods Used in Clinical Endodontics: A Systematic Review

Background

Ex vivo and in vitro studies have demonstrated the effectiveness of some irrigation protocols in reducing the bacterial load in the root canal system. However, standardized protocols have not yet been defined for the real clinical context due to many irrigation procedures available.

Objective

To evaluate the clinical endodontic protocols and limitations of irrigating solutions in the disinfection of the root canal system in patients with apical periodontitis.

Methods

PubMed, Scopus, Embase, Web of Science, and Cochrane databases were searched for randomized controlled trials (RCT) published until January 2021. Hand searching was also performed. Studies focused on evaluating the effectiveness of irrigating solutions and/or irrigation activation methods in reducing the bacterial load in the root canal system were considered. The Cochrane risk-of-bias tool for randomized trials (RoB2) was used to assess the quality of the studies.

Results

Four hundred and twenty eight published articles were identified. After removing the duplicate studies and analyzing full texts, seven RCTs were selected. Two studies compared pure NaOCl with some combination of NaOCl with HEDP and MTAD. Two studies analyzed the antibacterial efficacy of NaOCl and chlorhexidine (CHX). Three studies compared conventional needle irrigation with different irrigation activation methods (PUI, XP-endo finisher, F-file activator, EndoVac activator). The review attained a satisfactory methodology. The main results of each included study were described.

Discussion

Activation methods provide significantly higher biofilm reduction than conventional needle irrigation methods. Combinations of NaOCl with different chelating agents were ineffective in terms of antimicrobial, but it could potentially increase the risk of irrigant extrusion. However, the irrigating protocols were not carefully detailed, especially those regarding the irrigants application time or total volume. The existing literature lacks high-quality studies. The level of evidence is moderate.

Conclusions

The available data is too heterogeneous to compare and identify the superiority of specific valuable irrigation protocols in each clinical context. Application time, volume, and activation methods should be standardized to determine the optimal irrigating procedures to reduce the bacterial load and ensure higher predictability of the endodontic treatment.

Systematic Review Registration

(https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=218555), PROSPERO registration: CRD42020218555.

Vertical root fractures: A time-dependent clinical condition. A case-control study in two colombian populations

Background

This nested case-control study can be viewed as an efficient way to sample subjects from a large cohort study case-control study aimed to analyze the effect of different clinical factors on the appearance of vertical root fractures in endodontically-treated teeth (ETT) over time.

Material and Methods

By matching 90 cases and 270 controls nested in a cohort of 450 patients. Incident “cases” included those ETT in which a confirmed VRF. The “controls” were ETT with clinical and radiographic evidence of normality. When an “incident case” was detected, three random “controls” according to the evaluation time registered in years were selected. Time interval corresponded to the exposure time from the end of the endodontic treatment until the tooth was included in the study. Demographic and clinical parameters included: age, gender, type, and location of the tooth, type of endodontic treatment, number of appointments necessary to complete the endodontic treatment, use of intra-canal medication, the apical extension of the filling, type of coronal restoration, the role of the tooth in the rehabilitation treatment, presence of intra-radicular posts, and presence of an adjacent implant, were analyzed over time. Statistical analysis: univariate descriptive analysis, Pearson’s χ2 test, and a logistic regression model adjusted for the most significant variables with a 95% confidence interval.

Results

The prevalence of vertical root fractures was 16.42%. The multivariate analysis confirmed that re-treatment (OR:12.19; OR:4.28;P<0.05) lasting five to ten years and intra-canal medication (OR:6.16;P=0.004) for more than eleven years significantly more associated with the risk of vertical root fracture. For teeth with intra-canal post or direct coronal restorations, the risk of vertical root fracture was three times lower.

Conclusions

Endodontic re-treatment and the use of intracanal medication such as calcium hydroxide should be considered primary and secondary risk factors, respectively, according to the appearance of VRF over time.

Key words:Apical surgery, endodontic re-treatment, endodontically-treated teeth, risk factors, vertical root fracture.

Radiographic periapical healing associated with root-treated teeth accessed through existing crowns: a historical controlled cohort study

OBJECTIVES

The aim of this study was to determine the periapical healing rate and complications arising from non-surgical root canal treatment (NSRCT) conducted through the existing and retained restoration, compared to that conducted after removal of restoration (direct or indirect) with subsequent placement of a new crown.

MATERIALS AND METHODS

Two-hundred-and-forty-five teeth met the inclusion criteria and were followed up for 2 years. One-hundred-and-six teeth had NSRCT completed through existing cast restorations, and 57 and 82 had the existing crowns and direct restorations removed (respectively) and received a new crown after NSRCT. Periapical healing was assessed radiographically using strict (complete healing) and loose (complete and incomplete healing) criteria. Multivariable logistic regression models were used to investigate the effect of prior restoration removal on periapical healing following NSRCT, adjusting for potential confounding (p < 0.05).

RESULTS

There was no significant (p > 0.05) difference in the periapical healing rates amongst teeth accessed through existing crowns (72%, 90%) versus those where crowns (79%, 93%) or direct restorations (77%, 90%) were removed for NSRCT. The findings were adjusted for the significant influencing factor: size of pre-operative radiolucency (p < 0.05). Of the 109 teeth that were initially accessed through existing crowns, 9 (8%) displayed porcelain fracture or crown de-cementation.

CONCLUSION

Performing root canal treatment through an existing full coverage restoration did not compromise periapical healing and was associated with a low incidence of associated complications.

CLINICAL RELEVANCE

Crown removal before NSRCT is not mandatory for periapical healing but requires a judicious pre-assessment of current and future marginal and restorative integrity.

In Vitro Comparative Evaluation of Effectiveness of Sodium Hypochlorite with Conventional Irrigation Method versus EndoVac and Ultrasonic Irrigation in the Elimination of Enterococcus faecalis from Root Canals

AIM

The aim of this study was to compare the decrease in bacterial population in the root canals with 2.5% sodium hypochlorite (NaOCl) and three irrigation systems: Conventional Needle Irrigation, Passive Ultrasonic Irrigation, and EndoVac Apical Negative Pressure Irrigation system.

MATERIALS AND METHODS

Access open was carried out in 48 extracted single-rooted maxillary and mandibular human premolar teeth. The canals were instrumented 1 mm short of apical foramen up to No. 50 size file; irrigated and apical foramen was sealed with cyanoacrylate. The teeth were mounted in plaster and autoclaved for 20 min at 121°C. The plaster blocks containing the teeth were inoculated with Enterococcus faecalis and incubated at 37°C for 24 h. The specimens divided randomly into four groups (n = 12) depending on the type of irrigation system used: Group 1: Conventional Irrigation Needle, Group 2: Ultrasonic system, Group 3: EndoVac Negative Pressure Irrigation system used with 2.5% NaOCl, and Group 4: Control group, normal saline irrigation. The normal saline is used as control. The samples were collected using 45 size sterile paper points and quantitative bacterial assessment was carried out by seeding each dilution on plates containing brain heart infusion broth. Then, incubated at 37°C for 7 days and colony-forming units were counted. Data obtained were statistically analyzed.

RESULTS

Statistically, EndoVac irrigation systems were more effective in reducing the number of bacteria than the other irrigation systems.

CONCLUSION

EndoVac irrigation system was more effective in reducing bacterial numbers in infected root canals than the other two irrigation systems.

Analysis of the smear layer generated by different activation systems: an in vitro study

OBJECTIVES

To evaluate via scanning electron microscopy the amount of smear layer generated during the use of sonic and ultrasonic activation systems with standardized short-term intentional contacts with the canal walls.

METHODOLOGY

Seventy single-root human teeth were randomly assigned to 2 control (n = 5 each): NC (negative control), PC (positive control) and four experimental groups (n = 15 each): NC (negative control), PC (positive control), G1 (passive ultrasonic irrigation with Irrisafe), G2 (ultrasonic irrigation with EndoUltra), G3 (sonic irrigation with Endoactivator), G4 (sonic irrigation with Eddy). Samples were instrumented with ProTaper Next®. An irrigation protocol with sodium hypochlorite (NaOCl) and ethylenediaminetetraacetic acid (EDTA) was followed for both PC and the experimental groups. Standardized intentional contacts were made in the mesial walls during 5 s at WL - 2 mm in all experimental groups. Two calibrated evaluators scored the smear layer generated with an ordinal scale by scanning electron microscopy. The weighted kappa coefficient (K_w) was calculated to determine the inter-observer agreement. Post-consensus ordinal data were analyzed using the ordinal (linear) chi-square test.

RESULTS

When the agitation file is in contact with dentine walls, Irrisafe® significantly generated the least amount of smear layer in the coronal third (p < 0.05). Both in the middle and apical third, activation with Irrisafe® also showed statistically significant better results than Eddy™ and EndoUltra®. Endoactivator® showed significant better results than EndoUltra® and Eddy™ in the apical third (p < 0.05).

CONCLUSIONS

Irrisafe generated the least amount of smear layer in the entire canal and similar to Endoactivator in the apical third when the agitation file is in contact with dentine walls.

CLINICAL RELEVANCE

The smear layer is generated during activation. It is common to apply irrigation protocols where after the removal of the smear layer using chelants, a final rinse and activation is carried out but there are no previous studies analyzing the possible creation of a new smear layer with this final activation.

Fracture necrosis: A risk indicator for tooth loss

BACKGROUND AND OVERVIEW

The term "fracture necrosis" has been used to describe the condition found in a minimally restored tooth without a history of trauma when the suspected etiology for the loss of pulpal vitality is a crown-originating fracture. Teeth with fracture necrosis have a poor prognosis, and, when accompanied by characteristic radiographic findings, extraction may be considered the primary treatment option.

CASE DESCRIPTIONS

Two adult men with crown-originating fractures and suspected fracture necrosis had localized periodontal bone and attachment loss associated with severe pain on mastication from mandibular second molars. In case 1, the patient desired to retain the tooth despite an unfavorable prognosis. Nonsurgical root canal therapy and a crown prolonged tooth survival for only 30 months. The patient in case 2 requested extraction after a thorough review of his dental condition and tooth prognosis.

CONCLUSIONS

A tooth with fracture necrosis may continue to harbor virulent microorganisms after root canal therapy. When these microorganisms have access to the periodontal attachment, progressive loss of supporting tissues can be expected.

PRACTICAL IMPLICATIONS

When weighing treatment options for teeth with fracture necrosis associated with characteristic radiographic findings, preference toward extraction and tooth replacement, rather than treatment aimed at tooth retention, may represent a sound clinical approach.

Influence of the coronal restoration on the outcome of endodontically treated teeth

Objective: The tooth weakens due to removal of hard tissue during an endodontic procedure. Many dentists find it difficult to choose between different coronal restorations after root canal treatment (RCT). Studies show that the coronal restoration may affect the endodontic prognosis. This student-based study had three aims. (1) Examine the choice of coronal restoration of endodontically treated teeth at a Scandinavian dental school, (2) examine the survival of these restorations and (3) evaluate the influence of the coronal restoration on the outcome of the RCT. Material and methods: Radiographic and clinical examination was performed on 127 posterior teeth. The quality of the root canal treatment and the periapical status (PAI-index) were evaluated. Results: 43.8% of the teeth were restored with an indirect coronal restoration and 47.2% with a direct coronal restoration. The period from finished root canal treatment until placement of a permanent coronal restoration was significantly longer for an indirect restoration than a direct restoration. The teeth treated with a PAI score of 1 and 2 following pulpectomy, necrotic pulp treatment and endodontic retreatment was 93.8%, 82.6% and 69.4%, respectively.Conclusion: There was no significant association between choice of coronal restoration and PAI-score.

Survival Rates of Teeth with Primary Endodontic Treatment after Core/Post and Crown Placement

INTRODUCTION

The objective of this study was to determine the effect of delayed placement of the core/post and crown on the outcomes of nonsurgical root canal therapy (NSRCT).

METHODS

According to the Delta Dental of Wisconsin claims database, 160,040 NSRCTs were completed with a core/post and a crown placed before the end of the continuous coverage period or occurrence of an untoward event. Untoward events were defined as a retreatment, apicoectomy, or extraction as defined by the Code on Dental Procedures and Nomenclature. Statistical analysis was performed by using a multivariable Cox proportional hazards model.

RESULTS

The survival rate from the time of crown placement to an untoward event was 99.1% at 1 year, 96.0% at 3 years, 92.3% at 5 years, and 83.8% at 10 years. Failure rates were greater when a core/post was placed more than 60 days after the NSRCT (adjusted hazard ratio, 1.08) and when the crown was placed more than 60 days after the core/post placement (adjusted hazard ratio, 1.14). Overall, the survival rates of NSRCT were greater when performed by an endodontist versus other providers.

CONCLUSIONS

On the basis of the information available from insurance claims data, this study shows that the long-term survival rates of initial endodontic therapy are adversely affected by the delayed placement of the final restoration and full coverage crown.

Influence of the internal anatomy on the leakage of root canals filled with thermoplastic technique

OBJECTIVES

The aim of this paper is to evaluate the influence of the internal anatomy on the leakage of root canals filled with the thermoplastic technique.

MATERIALS AND METHODS

The upper central incisors (UCI) and mesial roots of the lower molars (MRLM) (n = 12 each) were tested regarding leakage using the gas-enhanced permeation test (GEPT) after root filling. The quality of the root fillings was assessed using micro-computed tomography (μCT) by superimposing scans before and after treatment to calculate unfilled volume. The calculated void volume was compared between the groups and correlated to the measured leakage values. Data were analyzed using t test and Pearson's correlation tests (p < 0.05).

RESULTS

The mean void volume did not differ between UCI and MRLM (13.7 ± 6.2% vs. 14.2 ± 6.8%, respectively). However, significantly more leakage was evident in the MRLM (p < 0.001). While the leakage correlated highly to the void volume in the MRLM group (R ² = 0.981, p < 0.001), no correlation was found in UCI (R ² = 0.467, p = 0.126).

CONCLUSION

MRLM showed higher leakage values, which correlated to the void volume in the root canal fillings.

CLINICAL RELEVANCE

Care should always be taken while doing root canal treatments, but attention to teeth with known/expected complex root canal anatomy should be considered.

Efficacy of passive ultrasonic irrigation in removing root filling material during endodontic retreatment

Abstract Introduction The aim of endodontic retreatment is to remove the previous root filling materials completely to allow for the subsequent steps of cleaning, canal shaping and filling replacement. Objective To evaluate the efficacy of passive ultrasonic irrigation (PUI) in the removal of residual root filling material after removing the bulk of the root filling with nickel-titanium rotary instruments. Material and method Eighteen mesial isthmus-containing roots of human mandibular molars were prepared and filled. The root canal filling was removed with the ProTaper Retreatment system and K-files. The specimens were randomized into 2 groups (n = 9), both irrigated with 2.5% NaOCl and 17% EDTA. In the conventional group, an irrigation syringe was used. In the PUI group, the PUI technique was used. The roots were sectioned longitudinally and evaluated under stereomicroscopy. Student’s t test was used to compare groups and the general linear model was used to compare the apical, cervical, and middle root thirds within each group, in regard to the percentages of remaining residual filling material. Result There was no statistically significant intergroup difference, irrespective of which root third was evaluated (P > 0.05). In the PUI group, the apical third showed a significantly higher percentage of residual filling material, in comparison with the cervical (P = 0.038) and middle (P = 0.029) thirds. Conclusion The PUI technique was not more effective than the conventional irrigation technique in removing residual root filling material during endodontic retreatment in root canals with a complex anatomy.

Complex Apical Intraradicular Infection and Extraradicular Mineralized Biofilms as the Cause of Wet Canals and Treatment Failure: Report of 2 Cases

This article describes 2 cases that showed persistent intracanal exudation (wet canal) even after several visits of antimicrobial endodontic treatment. Histologic and histobacteriologic investigation was conducted for determination of the cause. The 2 cases involved teeth with apical periodontitis lesions, which presented persistent exudation refractory to treatment after several visits. In case 1, it was not possible to achieve a dry canal, and surgery had to be performed. In case 2, attempts to dry the canal succeeded and the canal was filled, but follow-up examination showed an enlarged apical periodontitis lesion and extraction was performed. Biopsy specimens consisting of the root apex and apical periodontitis lesion for case 1 and the whole root for case 2 were subjected to histologic and histobacteriologic analyses. Both cases showed complex bacterial infection in the apical root, affecting both the intraradicular space and the outer root surface. Case 1 showed bacterial biofilms in ramifications, on untouched walls, and extending to the external root surface to form a thick and partially mineralized structure with high bacterial density. Different bacterial morphotypes were evidenced. Case 2 had a ledge on the apical canal wall created during instrumentation, which was filled with necrotic debris, filling material, and bacteria. The walls of the apical portion of the canal were covered by a bacterial biofilm, which was continuous with a thick extraradicular biofilm covering the cementum and dentin in resorptive defects. The extraradicular biofilm showed areas of mineralization and was dominated by filamentous bacteria. The 2 cases with wet canals and treatment failure were associated with complex persistent infection in the apical part of the root canal system extending to form thick and partially mineralized biofilm structures (calculus) on the outer apical root surface.

Dentin tubule invasion by Enterococcus faecalis under stress conditions ex vivo

Enterococcus faecalis is the species most frequently isolated from failed endodontic treatments because it can survive under stress conditions imposed by root canal treatment. The objective of this study was to determine the ability of E. faecalis to invade dentine tubules under alkaline and energy-starvation stress and to explore the potential mechanisms. Roots from single-rooted human teeth were infected with E. faecalis under alkaline and energy-starvation stress conditions. After 4 wk of culture, samples were processed to establish the tubule-penetration distance. In addition, the hydrophobicity of E. faecalis cells under these conditions was analysed and the expression of genes involved in adhesion was quantified by real-time quantitative PCR. Culture of E. faecalis under alkaline and energy-starvation stress conditions resulted in a marked reduction of tubule-penetration distance, a significant increase in hydrophobicity of the bacterial surface, and marked down-regulation of most adhesin genes compared with E. faecalis cultured in tryptic soy broth. The results indicate that the dentine tubule invasion ability of E. faecalis was markedly decreased under alkaline and glucose-starvation stress conditions, possibly because of the increase of hydrophobicity and down-regulation of some adhesion genes.

Sealing ability of root-end filling materials

BACKGROUND

The aim of this research was to compare the apical sealing ability of different root-end filling materials (SuperEBA(®), ProRoot MTA(®), thermoplasticized gutta-percha + AH-Plus(®), thermoplasticized RealSeal(®)), by means of microbial indicators.

MATERIALS AND METHODS

Thus, 50 human single-rooted teeth were employed, which were shaped until size 5 0, retro - prepared with ultrasonic tips and assigned to 4 groups, retro-filled with each material or controls. A platform was employed, which was split in two halves: upper chamber-where the microbial suspension containing the biological indicators was introduced (E. faecalis + S. aureus + P. aeruginosa + B. subtilis + C. albicans); and a lower chamber containing the culture medium brain, heart influsion, where 3 mm of the apical region of teeth were kept immersed. Lectures were made daily for 60 days, using the turbidity of the culture medium as indicative of microbial contamination. Statistical analyses were carried out at 5% level of significance.

RESULTS

The results showed microbial leakage at least in some specimens in all of the groups. RealSeal(®) has more microbial leakage, statistically significant, compared to ProRoot(®) MTA and SuperEBA(®). No significant differences were observed when compared ProRoot(®) MTA and SuperEBA(®). The gutta-percha + AH Plus results showed no statistically significant differences when compared with the other groups.

CONCLUSIONS

All the tested materials showed microbial leakage. Root-end fillings with Super-EBA or MTA had the lowest bacterial filtration and RealSeal shows highest bacterial filtration.

Impact of the quality of coronal restoration and root canal filling on the periapical health in adult syrian subpopulation

Background:

The purpose of this study was to determine the status of periapical tissues of endodontically treated teeth according to coronal restorations and root canal fillings separately and in concomitant in adult Syrian subpopulation.

Methods:

784 endodontically treated teeth from two hundred randomly selected Syrian adult patients were radiographically evaluated. According to predetermined criteria, the quality of coronal restorations and root canal filling of each tooth was scored as adequate or inadequate. The status of periapical tissues was also classified as healthy or diseased. Results were analyzed using Chi-squared test.

Results:

Adequate coronal restorations were determined in 58.54% of cases which was accompanied with less periapical pathosis than that in teeth with inadequate restorations (P < 0.01). 14% of teeth were restored by posts which showed no significant impact on the periapical tissues health. 18.5% of endodontic treatments were evaluated as adequate with less number of periapical radiolucencies than that of inadequate root canal fillings (P < 0.01). Absence of periapical pathosis was 96.6% in cases with both adequate coronal restorations and root canals fillings. The rate was 88.5% in cases with only adequate root canals fillings, and about 70% in cases with only adequate coronal restorations. When the treatment was inadequate in both coronal and root canals fillings, success rate was only observed in 48.8%.

Conclusion:

The most important factor with regard to the periradicular tissue health is the quality of root canal filling without neglecting the influence of coronal restoration (regardless of its type). There is a high prevalence rate of periapical pathosis in Syrian subpopulation due to poor dental practice.

Infiltração marginal microbiana em selamento coronário duplo

Introdução: O selamento coronário deve ser eficiente em impedir a penetração de saliva e seus contaminantes para o interior do sistema de canais radiculares. Objetivo: Avaliar o grau de infiltração microbiana em selamento duplo coronário utilizando Coltosol® associado ao MaxxionR® e ao Bioplic®. Material e método: Foram utilizados dentes pré-molares humanos extraídos, nos quais foram realizadas aberturas coronárias padronizadas com seis milímetros de profundidade. Os grupos foram divididos de acordo com os cimentos restauradores provisórios: Grupo I – Bioplic®; Grupo II: Bioplic® + Coltosol®; Grupo III: Maxxion R®; Grupo IV: Maxxion R® + Coltosol®; Grupo V - Coltosol®; Grupo controle. Foi confeccionado um dispositivo adaptando-se os dentes na porção inferior de tubos Eppendorf®, de modo que dois terços se projetem para fora do tubo plástico. O dispositivo foi fixado em frasco de vidro, contendo 7 mL de caldo estéril "Brain Heart Infusion". Na porção superior do tubo Eppendorf, foi realizada a inoculação de Enterococcus faecalis. A leitura foi realizada a cada 24h, durante 30 dias, avaliando-se a turvação no meio de cultura em contato com o ápice dentário. Os resultados foram submetidos ao teste estatístico Kruskal-Wallis (p<0,05). Resultado: Houve infiltração em todos os grupos ao final dos 30 dias e os grupos I e IV apresentaram 50% de infiltração. Os grupos IV e V apresentaram infiltração em cinco dias e o grupo III, em 26 dias. Conclusão: A associação entre os cimentos restauradores provisórios não impediu nem diminuiu a infiltração marginal de Enterococcus faecalis.

Bacterial leakage in root canals filled with AH Plus and dentine bonding agents

OBJECTIVE

The aim of this study was to compare the efficacy of different dentine adhesives in delaying the coronal bacterial leakage of Enterococcus faecalis in filled root canals. Materials and methods. Ninety-five lower incisors of patients >65 years of age were instrumented using the ProTaper system and were irrigated with 1 mL of 2.5% sodium hypochlorite (NaOCl) alternated with 1 mL 17% EDTA between each file change. Final irrigation was performed with 5 mL of 17% EDTA and then flushed with 5 mL of distilled water. The teeth were randomly divided into five experimental groups (n = 15/group) and one of the following dentine adhesives was applied: (1) AdheSE; (2) Excite DSC; (3) Clearfil Protect Bond; (4) One Coat 7.0; or (5) Control group without adhesive. After filling the root canals, the samples were mounted on a double chamber device to evaluate the bacterial filtration of E. faecalis during a period of 240 days. The results underwent non-parametric Kaplan-Meier survival analysis and comparisons among groups were done using the Log-Rank test.

RESULTS

At 240 days, E. faecalis was detected in samples of all groups in the lower chamber. The highest survival value was obtained by One Coat 7.0, giving statistically significant differences from the other groups, whereas Clearfil Protect Bond, AdheSE and Excite DSC showed similar behaviours, likewise similar to the Control group.

CONCLUSIONS

One Coat 7.0 adhesive system provides the longest survival value to delay E. faecalis coronal leakage in filled root canals.

Correlation between clinical and histologic pulp diagnoses

INTRODUCTION

Clinicians routinely face conditions in which they have to decide whether the dental pulp can be saved or not. This study evaluated how reliable the clinical diagnosis of normal pulp/reversible pulpitis (savable pulp) or irreversible pulpitis (nonsavable pulp) is when compared with the histologic diagnosis.

METHODS

The study material consisted of 95 teeth collected consecutively in a general practice over a 5-year period and extracted for reasons not related to this study. Based on clinical criteria, teeth were categorized as having normal pulps, reversible pulpitis, or irreversible pulpitis. The former 2 were grouped together because they represent similar conditions in terms of prognosis. Teeth were processed for histologic and histobacteriologic analyses, and pulps were categorized as healthy, reversibly inflamed, or irreversibly inflamed according to defined criteria. The number of matching clinical/histologic diagnosis was recorded.

RESULTS

The clinical diagnosis of normal pulp/reversible pulpitis matched the histologic diagnosis in 57 of 59 (96.6%) teeth. Correspondence of the clinical and histologic diagnosis of irreversible pulpitis occurred in 27 of 32 (84.4%) cases. Infection advancing to the pulp tissue was a common finding in teeth with irreversible pulpitis but was never observed in normal/reversibly inflamed pulps.

CONCLUSIONS

Findings using defined criteria for clinical and histologic classification of pulp conditions revealed a good agreement, especially for cases with no disease or reversible disease. This means that the classification of pulp conditions as normal pulps, reversible pulpitis, and irreversible pulpitis has high chances of guiding the correct therapy in the large majority of cases. However, there is still a need for refined and improved means for reliable pulp diagnosis.

Extraradicular infection as the cause of persistent symptoms: a case series

INTRODUCTION

This article describes 3 cases that presented persistent symptoms after appropriate endodontic treatment. Histopathologic and histobacteriologic investigation were conducted for determination of the cause.

METHODS

Three cases are reported that presented with persistent symptoms after endodontic retreatment (cases 1 and 2) or treatment (case 3). Periapical surgery was indicated and performed in these cases. The biopsy specimens, consisting of root apices and the apical periodontitis lesions, were subjected to histopathologic and histobacteriologic analyses.

RESULTS

Case 1 was an apical cyst with necrotic debris, heavily colonized by ramifying bacteria, in the lumen. No bacteria were found in the apical root canal system. Case 2 was a granuloma displaying numerous bacterial aggregations through the inflammatory tissue. Infection was also present in the dentinal tubules at the apical root canal. Case 3 was a cyst with bacterial colonies floating in its lumen; bacterial biofilms were also seen on the external apical root surface, filling a large lateral canal and other apical ramifications, and between layers of cementum detached from the root surface. No bacteria were detected in the main root canal.

CONCLUSIONS

Different forms of extraradicular infection were associated with symptoms in these cases, leading to short-term endodontic failure only solved by periapical surgery.

Microbial invasion of dentinal tubules: a literature review and a new perspective

Various features of endodontic microbiology have been investigated using various methods. The aim of the present study was to review the existing literature on endodontic microbiology in dentinal tubules, and to present the features of two cases with endodontic pathology. An electronic search was performed with a search string created ad hoc. Ex vivo and in vitro studies were included, recording the method of detection and characteristics of analyzed teeth. Twenty studies fulfilled the inclusion criteria. Seven of them were in vitro laboratory studies on teeth inoculated after extraction, while 13 were ex vivo studies on extracted, infected teeth. Endodontic bacteria were detected in dentinal tubules, both as single units and as biofilm aggregates. Two similar in vitro cases presented here corroborate the latter findings. A number of techniques have been utilized to observe bacteria in the dentinal tubule ecosystem. Dentinal tubules are favorable niches for microbial survival, either in the form of monomicrobial or polymicrobial communities.

Assessment of the sealing abilities of several root canal sealers and filling methods

OBJECTIVE

To evaluate the sealing abilities of two root canal sealers (epoxy resin-based AH Plus(®) and polydimethylsiloxane-based GuttaFlow(®)) and of five root filling techniques (lateral condensation, matched taper single gutta-percha point, laterally condensed-matched taper gutta-percha point, Thermafil(®) and continuous wave of condensation), using a bacterial leakage model.

MATERIALS AND METHODS

One hundred and seventy-four single-rooted human teeth were randomly divided into 10 test groups (n = 15) and two control groups (n = 12). The roots that were filled with the test material, using the different root filling techniques, were mounted in a two-chamber bacterial leakage model and Enterococcus faecalis was added to the upper chambers. The lower chambers of all of the specimens were checked every day during the test period (100 days). The day of turbidity was recorded for each sample. Statistical analysis was performed using the Kaplan-Meier and log-rank tests.

RESULTS

There was no significant difference between the epoxy resin-based and the polydimethylsiloxane-based sealers, irrespective of the filling techniques used (p > 0.05). The continuous wave of condensation technique was found to be superior to the other techniques (p < 0.05). The difference between the other groups was insignificant (p > 0.05).

CONCLUSIONS

AH Plus and GuttaFlow sealers showed similar levels of sealing ability. The continuous wave of condensation technique had the best sealing capability when compared to the other techniques.

The presence and distribution of bacteria in dentinal tubules of root filled teeth

AIM

To investigate the distribution of bacteria within the dentine tubular network in a two-chamber model in order to determine a possible route of penetration.

METHODOLOGY

Root canals of teeth in the experimental group (n = 16) were instrumented and root filled using AH26 and gutta-percha. Canals in the teeth serving as positive (n = 1) and negative (n = 1) controls were instrumented, but not root filled. A two-chamber model was fabricated for each root - upper chambers were inoculated weekly with Streptococcus gordonii in brain-heart infusion broth over 90 days. Turbidity of the lower chamber was checked daily. Samples that showed turbidity during the experimental period and samples that showed no signs of turbidity at 90 days were fractured and prepared for SEM examination. SEM examination for the presence of bacteria within the dentinal tubules was performed in the cervical, middle and apical root thirds. In each root third, the depth of bacterial penetration was recorded as inner, middle or outer dentine.

RESULTS

Bacteria were most commonly detected in the cervical third (14 of 30 areas). Irrespective of the root third examined, bacteria were most commonly detected in the inner dentine (i.e. adjacent to the root canal). Only two samples demonstrated bacterial penetration in the outer dentine.

CONCLUSION

The dentine tubular network provides a potential pathway for bacteria to penetrate tooth roots in a two-chamber model.

Radiographic assessment of the technical quality and periapical health of root-filled teeth performed by general practitioners in a Turkish subpopulation

Aim. The aim of this study was to evaluate by means of radiographs the technical quality of root fillings performed by dental practitioners. Methods and Material. Standardized periapical radiographs were made on 484 patients who received endodontic treatment in private practice. A total of 831 endodontically treated teeth with 1448 roots were evaluated for technical quality of the root canal filling and the periapical status of the teeth. Also, the apical status of each root-filled tooth was assessed according to the length, density, and taper of root fillings, and the presence of apical transportation, broken root instruments, and overfilled sealer or gutta-percha material was recorded for each root canal. Results. Of the endodontically treated teeth 26.6% had healthy periapical tissues, while technically good endodontic treatment constituted 12.8%. Based on the treatment success, there was no significant difference between the tooth groups. Statistical analysis of the data did not demonstrate statistically significant differences between the various parameters that were evaluated (P < 0.05). Conclusions. Technical quality of root fillings in a population who received treatment in private practice was poor and was consistent with a low prevalence of apical health. The probable reasons for this failure are multifactorial and may be improved if the operators improve their skills with continuing postgraduate education programs.

Exuberant Biofilm infection in a lateral canal as the cause of short-term endodontic treatment failure: report of a case

INTRODUCTION

This article describes a case in which signs and symptoms persisted in spite of the endodontic treatment following high standards to characterize a short-term failure.

METHODS

After several appointments of root canal treatment in an attempt to resolve persistent symptoms, including 106 days of calcium hydroxide intracanal medication, periradicular surgery was performed, and the root apex and the lesion were subjected to histologic and histobacteriologic analyses.

RESULTS

The lesion was diagnosed as a cyst, and the main root canal was free of bacteria and debris.

CONCLUSIONS

The cause of the short-term failure was an exuberant bacterial biofilm colonizing a lateral canal in the apical root segment. This case report highlights one of the major problems of modern endodontic therapy; bacteria located in areas distant from the main root canal can remain unaffected by treatment procedures and maintain disease. The challenge for researchers and clinicians that arises from this problem is to develop strategies, instruments, or substances that can reach those areas and achieve sufficient reduction in the infectious bioburden to permit predictable periradicular healing.

Influence of the quality of endodontic treatment and coronal restorations on the prevalence of apical periodontitis in a Turkish Cypriot population

OBJECTIVES

The aim of this study was to assess the prevalence of periapical lesions in root canal-treated teeth in a Turkish Cypriote population and to investigate the influence of the quality of root canal fillings and coronal restorations on the prevalence of periapical lesions.

SUBJECTS AND METHODS

The sample for this cross-sectional study consisted of 1,006 adult patients seeking routine dental care. Patients who had received dental care in the last 2 years were excluded. Radiographs of 2,200 root canal-treated teeth were evaluated. The teeth were grouped according to the radiographic quality of the root canal filling and the coronal restoration. Periapical status was assessed using periapical index (PAI) scores.

RESULTS

Of the 2,200 root canal-treated teeth, 1,364 (62%) had apical periodontitis as compared with 1,364 (5.5%) of the total sample. Root-filled teeth classified as adequately treated had apical periodontitis in 223 (26.6%) cases compared with 1,192 (87.7%) in teeth classified as inadequately root filled. PAI 1 scores of adequate root canal treatment were significantly higher than in inadequate root canal treatment, regardless of the quality or presence of coronal restorations (p < 0.01).

CONCLUSION

Our findings showed a high prevalence of periapical pathology with or without endodontic treatment and poor technical standard of both root fillings and coronal restorations of root-treated teeth. Hence, we suggest the need for better education for dental health providers so that they can perform better root canal treatments and coronal restorations.

Comparative evaluation of sealing properties of different obturation systems placed over apically fractured rotary NiTi files

Aim:

To evaluate sealing properties of different obturation systems placed over apically fractured rotary NiTi files.

Materials and Methods:

Forty freshly extracted human mandibular premolars were prepared by using Protaper (Dentsply-Maillefer, Ballaigues, Switzerland) or the RaCe (FKG Dentaire, La Chaux-de-Fonds, Switzerland) systems (n=20 for each), after which half of the specimens were subjected to instrument separation at the apical level. Roots with and without apically separated instruments (n=5) were filled with the two obturation systems i.e. Thermafil and lateral compaction technique. The modified glucose penetration setup was used to assess the microleakage. The leakage data was statistically analyzed.

Results:

The amount of leakage was significantly lower in specimens containing fractured instruments, regardless of the obturation method used. Roots obturated with Thermafil displayed significantly less leakage than cold lateral compaction technique, both, in the presence and absence of separated instruments. There was no significant difference among specimens prepared with ProTaper and RaCe when Thermafil obturation was done. But with cold lateral compaction technique, RaCe system showed less leakage as compared to ProTaper system.

Conclusion:

The type of obturation may play more important role than the type of instrument or retained/non-retained instrument factor.