Outcome of root canal treatment using Thermafil and cold lateral condensation filling techniques

The efficacy of premixed bioceramic sealers versus standard sealers on root canal treatment outcome, extrusion rate and post-obturation pain: A systematic review and meta-analysis

BACKGROUND

Limited evidence is available regarding the superior clinical properties of bioceramic sealers comparted with traditional standard sealers.

OBJECTIVES

This review aimed to answer the following research questions: 'In healthy patients requiring a root canal treatment (P), what is the efficacy of premixed bioceramic sealers (I) compared with traditional root canal epoxy resin-based sealers (C) in terms of survival, success rates (PICO1) sealer extrusion and resorption (PICO2) post-obturation pain (PICO3) (O)?'

METHODS

Authors independently searched three electronic databases: PubMed (including MEDLINE), Web of Science, Embase and Scopus up to 31 October 2023. This was accompanied by both grey literature and manual search. Detailed selection criteria were applied, namely mature permanent teeth requiring root canal treatment, premixed bioceramic sealer with gutta-percha as an intervention group, a standard filling technique as control group and full-text available in English. A random-effect meta-analysis was used to synthesize the body of evidence regarding the use of bioceramic sealers in root canal treatment and their impact on post-obturation pain. Effect sizes were represented as relative risks on a logarithmic scale for binary outcomes and as mean differences for continuous outcomes.

RESULTS

A total of 941 articles were identified. Fifteen Comparative clinical studies were finally included. Eleven were randomized clinical trials, and four were prospective clinical trials with control group. The follow-up of these studies was not greater than 2 years. No publication bias was observed in any study. No significant differences were observed between the two groups in terms of survival and success rates. A small non-significant lower risk of extrusion was observed for bioceramics. A small, non-significantly lower post-operative-pain within 24-h was observed when bioceramics were used.

DISCUSSION

The majority of current evidence shows inconsistencies in reporting and is of short-term duration. Robust prospective long-term trials are needed in this area to better support future recommendations.

CONCLUSION

This systematic review is the first to analyse several clinical outcomes using premixed sealers. Included studies differed in terms of clinical protocol and operator expertise, but reported a similar outcome when comparing bioceramic versus standard sealers. Tooth survival, treatment outcome, post-operative pain and periapical extrusion were similar and presented no significant differences between the two sealer types.

REGISTRATION

PROSPERO database (CRD42023449151).

Effectiveness of root canal filling materials and techniques for treatment of apical periodontitis: A systematic review

BACKGROUND

Apical periodontitis (AP) is an inflammatory disease of the apical periodontium as sequelae of pulp death. It is managed by disinfection and filling of the root canal space.

OBJECTIVES

The aim of this systematic review was to investigate whether obturation techniques and materials used for root canal filling led to the management of AP.

METHODS

A systematic review protocol was written following the preferred reporting items for systematic reviews and meta-analyses (PRISMA) checklist and registered on the international prospective register of systematic reviews (PROSPERO; CRD42021260275) including two populations, interventions, comparisons, outcomes and time (PICOT) for the research questions querying the effectiveness of obturation techniques (PICOT 1) and materials (PICOT 2) for the management of AP. Electronic searches were conducted on PubMed, ScienceDirect, Scopus and Embase search engines. Searches on International Endodontic Journal, Journal of Endodontics, Clinical Oral Investigations, Journal of Dental Research and Journal of Dentistry websites were also conducted, until May 2021. Both primary (tooth survival) and secondary outcomes were evaluated. The risk of bias was assessed by Cochrane RoB2 for the randomized and ROBINS-I for the nonrandomized trials.

RESULTS

The search strategy identified 1652 studies, with 1600 excluded on the title and abstract screening, leaving 52 studies for full-text screening. In total, 10 studies met the inclusion criteria. The obturation technique and materials used did not affect the outcome of AP. Vertical compaction resulted in faster resolution of periapical lesions. The oral health-related quality of life of patients treated with lateral condensation exhibited poorer outcomes compared with single matched cone after 6 months of recall.

DISCUSSION

The inclusion and exclusion criteria used for this systematic review enabled the capture of all the literature available on the effect of obturation techniques and materials on the outcome of AP. The data were heterogenous, and a number of articles investigating obturation techniques had no information on the materials and techniques used as they looked at the quality of fill.

CONCLUSIONS

Included studies did not find any difference between different procedures (PICOT 1) and materials (PICOT 2). The risk of bias was high, thus the findings should be interpreted with caution.

REGISTRATION

PROSPERO registration number: CRD42021260275.

Treatment of pulpal and apical disease: The European Society of Endodontology (ESE) S3-level clinical practice guideline

BACKGROUND

The ESE previously published quality guidelines for endodontic treatment in 2006; however, there have been significant changes since not only in clinical endodontics but also in consensus and guideline development processes. In the development of the inaugural S3-level clinical practice guidelines (CPG), a comprehensive systematic and methodologically robust guideline consultation process was followed in order to produce evidence-based recommendations for the management of patients presenting with pulpal and apical disease.

AIM

To develop an S3-level CPG for the treatment of pulpal and apical disease, focusing on diagnosis and the implementation of the treatment approaches required to manage patients presenting with pulpitis and apical periodontitis (AP) with the ultimate goal of preventing tooth loss.

METHODS

This S3-level CPG was developed by the ESE, with the assistance of independent methodological guidance provided by the Association of Scientific Medical Societies in Germany and utilizing the GRADE process. A robust, rigorous and transparent process included the analysis of relevant comparative research in 14 specifically commissioned systematic reviews, prior to evaluation of the quality and strength of evidence, the formulation of specific evidence and expert-based recommendations in a structured consensus process with leading endodontic experts and a broad base of external stakeholders.

RESULTS

The S3-level CPG for the treatment of pulpal and apical disease describes in a series of clinical recommendations the effectiveness of diagnosing pulpitis and AP, prior to investigating the effectiveness of endodontic treatments in managing those diseases. Therapeutic strategies include the effectiveness of deep caries management in cases with, and without, spontaneous pain and pulp exposure, vital versus nonvital teeth, the effectiveness of root canal instrumentation, irrigation, dressing, root canal filling materials and adjunct intracanal procedures in the management of AP. Prior to treatment planning, the critical importance of history and case evaluation, aseptic techniques, appropriate training and re-evaluations during and after treatment is stressed.

CONCLUSION

The first S3-level CPG in endodontics informs clinical practice, health systems, policymakers, other stakeholders and patients on the available and most effective treatments to manage patients with pulpitis and AP in order to preserve teeth over a patient's lifetime, according to the best comparative evidence currently available.

Removal of Thermafil obturators using two different techniques: A comparative Ex Vivo study

INTRODUCTION

The aim of this ex vivo study was to compare two techniques for removal of Thermafil obturators from curved root canals in mandibular molars.

METHODS

Sixty mesial root canals in extracted mandibular molars were distributed into matched pairs according to degree and radius of curvature and were prepared to size 35/.04 and obturated with Thermafil obturators size 35. Each tooth was embedded in resin, mounted in a mannequin head and isolated with rubber dam to simulate clinical conditions. Removal of obturators was undertaken under a dental operating microscope by an experienced endodontist using either the FragRemover loop device, or reciprocating NiTi instruments. Pre- and postoperative micro-CT scans were taken to compare the amount of remaining filling material and of removed dentin. Eventual problems during removal attempts were recorded.

RESULTS

Using Reciproc 24 carriers (80%) were removed, 16 in one piece, 8 in small pieces, in 6 cases removal failed. The FragRemover removed 12 carriers (40%), all of these completely, but in 18 cases removal failed (P < 0.05). Reciproc left less remaining filling material than the FragRemover (P < 0.05) but removed significantly more dentin in the apical part of the root canal (P < 0.01). There was no significant difference concerning the total amount of removed dentin (P > 0.05) between both groups. Seven complications occurred in the Reciproc group. In five teeth working length could not be reached, in two teeth a Reciproc file R25 fractured. With the FragRemover 64 complications occurred, in 36 cases, including second removal attempts, the loop slipped over the carrier, in 24 cases the top of the carrier was sheared off. In nine cases separation of the core occurred too far apically, not allowing further use of the FragRemover. In four cases the wire loop tore.

CONCLUSIONS

Reciproc was more effective in removal of Thermafil carriers, whereas using the FragRemover less dentin was removed in the apical part of the root canal and more obturation material was left.

The Use of Premixed Calcium Silicate Bioceramic Sealer with Warm Carrier-Based Technique: A 2-Year Study for Patients Treated in a Master Program

Background: Recently several calcium silicate flowable sealers have been introduced as endodontic materials for the root canal. This clinical study tested the use of a new premixed calcium silicate bioceramic sealer in association with the Thermafil warm carrier-based technique (TF). Epoxy-resin-based sealer with the warm carrier-based technique was the control group. Methodology: Healthy consecutive patients (n = 85) requiring 94 root canal treatments were enrolled in this study and assigned to one filling group (Ceraseal-TF n = 47, AH Plus-TF n = 47) in accordance with operator training and best clinical practice. Periapical X-rays were taken preoperatively, after root canal filling and after 6, 12 and 24 months. Two evaluators blindly assessed the periapical index (PAI) and sealer extrusion in the groups (k = 0.90). Healing rate and survival rate were also evaluated. Chi-square tests was used to analyze significant differences between the groups. Multilevel analysis was performed to evaluate the factors associated with healing status. Results: A total of 89 root canal treatments in 82 patients were analyzed at the end-line (24 months). The total drop-out was 3.6% (3 patients; 5 teeth). A total of 91.1% of healed teeth (PAI 1-2) was observed in Ceraseal-TF, with 88.6% in AH Plus-TF. No significant difference was observed on healing outcome and survival among the two filling groups (p > 0.05). Apical extrusion of the sealers occurred in 17 cases (19.0%). Of these, 6 occurred in Ceraseal-TF (13.3%) and 11 in AH Plus-TF (25.0%). Three Ceraseal extrusions were radiographically undetectable after 24 months. All the AH Plus extrusions did not change during the evaluation time. Conclusions: The combined use of the carrier-based technique and premixed CaSi-based bioceramic sealer showed clinical results comparable with carrier-based technique and epoxy-resin-based sealer. The radiographical disappearance of apically extruded Ceraseal is a possible event in the first 24 months.

Single versus multiple visits for endodontic treatment of permanent teeth

BACKGROUND

Root canal treatment (RoCT), or endodontic treatment, is a common procedure in dentistry. The main indications for RoCT are irreversible pulpitis and necrosis of the dental pulp caused by carious processes, coronal crack or fracture, or dental trauma. Successful RoCT is characterised by an absence of symptoms (i.e. pain) and clinical signs (i.e. swelling and sinus tract) in teeth without radiographic evidence of periodontal involvement (i.e. normal periodontal ligament). The success of RoCT depends on a number of variables related to the preoperative condition of the tooth, as well as the endodontic procedures. RoCT can be carried out with a single-visit approach, which involves root canal system obturation (filling and sealing) directly after instrumentation and irrigation, or with a multiple-visits approach, in which the treatment is completed in two or more sessions and obturation is performed in the last session. This review updates the previous versions published in 2007 and 2016.

OBJECTIVES

To evaluate the benefits and harms of completion of root canal treatment (RoCT) in a single visit compared to RoCT over two or more visits, with or without medication, in people aged over 10 years.

SEARCH METHODS

We used standard, extensive Cochrane search methods. The latest search date was 25 April 2022.

SELECTION CRITERIA

We included randomised controlled trials and quasi-randomised controlled trials in people needing RoCT comparing completion of RoCT in a single visit compared to RoCT over two or more visits.  DATA COLLECTION AND ANALYSIS: We used standard Cochrane methods. Our primary outcomes were 1. tooth extraction and 2. radiological failure after at least one year (i.e. periapical radiolucency). Our secondary outcomes were 3. postoperative and postobturation pain; 4. swelling or flare-up; 5. analgesic use and 6. presence of sinus track or fistula after at least one month. We used GRADE to assess certainty of evidence for each outcome. We excluded five studies that were included in the previous version of the review because they did not meet the current standard of care (i.e. rubber dam isolation and irrigation with sodium hypochlorite).

MAIN RESULTS

We included 47 studies with 5805 participants and 5693 teeth analysed. We judged 10 studies at low risk of bias, 17 at high risk of bias and 20 at unclear risk of bias. Only two studies reported data on tooth extraction. We found no evidence of a difference between treatment in one visit or treatment over multiple visits, but we had very low certainty about the findings (risk ratio (RR) 0.46, 95% confidence interval (CI) 0.09 to 2.50; I2 = 0%; 2 studies, 402 teeth). We found no evidence of a difference between single-visit and multiple-visit treatment in terms of radiological failure (RR 0.93, 95% CI 0.81 to 1.07; I2 = 0%; 13 studies, 1505 teeth; moderate-certainty evidence). We found evidence of a higher proportion of participants reporting pain within one week in single-visit groups compared to multiple visit groups (RR 1.55, 95% CI 1.14 to 2.09; I2 = 18%; 5 studies, 638 teeth; moderate-certainty evidence).  We found no evidence of a difference in the proportion of participants reporting pain until 72 hours postobturation (RR 0.97, 95% CI 0.81 to 1.16; I2 = 70%; 12 studies, 1329 teeth; low-certainty evidence), pain intensity until 72 hours postobturation (mean difference (MD) 0.26, 95% CI -4.76 to 5.29; I2 = 98%; 12 studies, 1258 teeth; low-certainty evidence) or pain at one week postobturation (RR 1.05, 95% CI 0.67 to 1.67; I2 = 61%; 9 studies, 1139 teeth; very low-certainty evidence). We found no evidence of a difference in swelling or flare-up incidence (RR 0.56 95% CI 0.16 to 1.92; I2 = 0%; 6 studies; 605 teeth; very low-certainty evidence), analgesic use (RR 1.25 95% CI 0.75 to 2.09; I2 = 36%; 6 studies, 540 teeth; very low-certainty evidence) or sinus tract or fistula presence (RR 1.00, 95% CI 0.24 to 4.28; I2 = 0%; 5 studies, 650 teeth; very low-certainty evidence). Subgroup analysis found no differences between single-visit and multiple-visit RoCT for considered outcomes other than proportion of participants reporting post-treatment pain within one week, which was higher in the single-visit groups for vital teeth (RR 2.16, 95% CI 1.39 to 3.36; I2 = 0%; 2 studies, 316 teeth), and when instrumentation was mechanical (RR 1.80, 95% CI 1.10 to 2.92; I2 = 56%; 2 studies, 278 teeth).

AUTHORS' CONCLUSIONS

As in the previous two versions of the review, there is currently no evidence to suggest that one treatment regimen (single-visit or multiple-visit RoCT) is more effective than the other. Neither regimen can prevent pain and other complications in the 12-month postoperative period. There was moderate-certainty evidence of higher proportion of participants reporting pain within one week in single-visit groups compared to multiple-visit groups. In contrast to the results of the last version of the review, there was no difference in analgesic use.

Evaluation of the root filling quality with experimental carrier-based obturators: a CLSM and FEG-SEM analysis

This study evaluated tubule penetration of GuttaFlow Bioseal with cold single cone or carrier-based technique, under confocal laser scanning microscopy (CLSM). Twenty straight single-rooted teeth were instrumented with Hyflex CM and divided in two groups (n = 10) according to the obturation method: single cold gutta-percha cones; experimental carrier-based obturators. GuttaFlow Bioseal, labelled with Rhodamine B dye, was used as sealer in both groups. Teeth transversally sectioned were observed under CLSM. Percentage of sealer penetration and integrity of sealer layer perimeter were measured. Surface and microstructural characteristics of obturators and gutta-percha cones were compared by FEG-SEM and EDX analysis. No significant differences were found between groups for each examined parameter. Significant differences (P < 0.05) were reported mainly within groups. Integrity was similar among and within groups. FEG-SEM/EDX analysis of obturators revealed the presence of Ba and Zn. Carrier-based obturation technique associated with GuttaFlow Bioseal does not seem to affect sealer penetration into dentinal tubules.

Outcomes of Primary Root Canal Therapy: An updated Systematic Review of Longitudinal Clinical Studies Published between 2003 and 2020

Background

A comprehensive effort to evaluate outcomes of primary root canal therapy (RCT) between 1966 and 2002 was published by Ng et al. (2007, International Endodontic Journal, 40, 921; 2008, International Endodontic Journal, 41, 6). Changes in endodontic materials and treatment methods warrant an updated analysis of outcomes.

Objectives

This study aimed to (1) quantify the success rates of primary RCT published between 2003 and 2020; and (2) investigate the influence of some characteristics known/suspected to be associated with treatment outcomes.

Methods

An electronic search was performed in the following databases (01‐01‐2003 to 12‐31‐2020): Pubmed, Embase, CINHAL, Cochrane and Web of Science. Included study designs were longitudinal clinical studies (randomized control trials, cohort studies, retrospective observational studies). Studies with at least twelve‐months of post‐operative review and success rates based on clinical and radiographic criteria were analysed. The terms ‘strict’ (complete resolution of periapical lesion) or ‘loose’ (reduction in size of existing periapical lesion) were used to describe the outcome criteria. Weighted, pooled success rates were calculated. Random effects meta‐regression models were used to investigate potential sources of statistical heterogeneity. The Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach was used to evaluate for quality assessment of the included studies.

Results

Forty‐two studies were included in the review. Meta‐analyses showed that the weighted pooled success rates were estimated to be 92.6% (95% CI: 90.5%–94.8%) under ‘loose criteria’ and 82.0% (95% CI: 79.3%–84.8%) under ‘strict’ criteria. The most significant areas of study heterogeneity were year of publication and qualification of operator. The majority (64.29%) of studies were considered to be of low quality of evidence.

Discussion

Biological factors continue to have the most significant impact on RCT outcomes. The technological method of instrumentation had no significant effect. The quality of evidence was based primarily on study design and only randomized control trials were considered to be ‘high’ quality of evidence.

Conclusions

The reported success rates show improvement over time. Weighted success rates for studies with a minimum of four‐years follow‐up had better outcomes, compared to those with less than four years, when ‘strict criteria’ were used.

Registration

PROSPERO database (CRD42021226311).

A critical analysis of research methods and experimental models to study root canal fillings

Canal filling materials and techniques have been one of the most studied topics in Endodontics. A simple search using the mesh term "root canal filling" in PubMed revealed more than 11,000 articles, an impressive number that is much higher than "root canal disinfection" (5,544 articles) or even the popular "root canal preparation" (8,527 articles). The overriding importance attributed to root filling procedures is not merely intuitive. It derived from the appealing relevance given by the appearance of the white lines in common radiographs grounded on retrospective clinical data that had identified the quality of a root filling as one of the major causes of treatment failure (lack of healing). Since the publication of the Washington study, impressive efforts have been made for the release of new materials and techniques, as well as, for the development of a plethora of laboratory methods to assess the quality of root filling procedures. This narrative review aims to address and discuss the most relevant laboratory methods to assess the root canal filling. Since filling quality improvements have not translated into higher success rates, as reported in longitudinal clinical studies, more than to deliver a simple methodology-based review, this paper aims to present an in-depth critical view on the assessment of laboratory methods used to study the filling materials and techniques. Recent data indicate that the long-term dimensional stability/degradation over time of endodontic sealers plays a central role in the treatment outcome. In this context, laboratory methods should be developed focusing on predicting, at least to some degree, the long-term clinical behaviour of root canal fillings, rather than simply ranking different materials or techniques.

Effect of Different Treatment Regimen and Types of Endodontic Sealers on Pain and Periapical Radiographic Changes

INTRODUCTION: The study aims as a pilot study to evaluate the effect of different treatment regimen and different types of endodontic sealers on pain and periapical radiographic changes was studied. MATERIALS AND METHODS: Forty patients in need of an endodontic root canal treatment on anterior teeth were selected and divided into two groups (20 patients each), according to the endodontic treatment protocol (single or multiple visits). Then, each group was subdivided into two subgroups according to sealer used 10 each (AH Plus Jet resin sealer, Total Fill Bioceramic Sealer). To record pain intensity of the patients at different intervals: 1, 2, 3, 7 days, a visual analog scale was used. Furthermore, patients were recalled after 1, 3, 6, 9 months to evaluate periapical radiographic changes. RESULTS: Showed that as regard pain assessment both tested endodontic sealers, as well as single or multiple visits have no statistically significant difference between pain values of patients during all the observation period from immediately post-operative, after 4, 12, 24, 48, 72 h as well as after 7 days (p > 0.05). As regard lamina dura thickness, results showed that with both tested endodontic sealers as well as single or multiple visits, there was no statistically significant difference between lamina dura thickness of patients after 1 month, 3, 6 as well as after 9 months. CONCLUSIONS: Neither number of visits of endodontic treatment nor type of sealer used for obturation affects post-operative pain and thickness of lamina dura.

Evaluation of the sealer/gutta-percha ratio on sets of root section surfaces of some extracted teeth sealed using the cold lateral condensation technique

Canal filling must be well adapted to the walls of the root canal to prevent bacterial infiltration. Endodontic seals play an essential role in ensuring tightness, without which the canal filling would suffer infiltrations. This study aimed to evaluate the areas occupied by the two components of the canal filling, as well as the sealer/gutta-percha ratio in the root canals of the maxillary central incisors after their filling using the cold lateral condensation technique with gutta-percha. Thirty extracted upper central incisors were rotatably prepared with ProTaper Universal up to F3 and sealed using the cold lateral condensation technique with gutta-percha. After setting the sealer, the roots of the teeth were sectioned perpendicularly to 1 (L1), 3 (L3), 6 (L6), and 8 (L8) mm from the apex. The surface of the sections was analyzed with a Leica EZ4D stereomicroscope and photographed at two magnification orders: 10x and 25x. The areas corresponding to the gutta-percha, sealer, gaps, and root canal were expressed in pixels using the ImageJ software, version 1.50i. The difference in the representation of sealer areas, gutta-percha and voids was statistically significantly different for all four sections analyzed. The best adaptation of the canal obturation was observed in L1 and L3. The gutta-percha area was statistically significantly higher than that of the sealer for the L1, L3, and L6 levels, while the sealer/gutta-percha ratio recorded the lowest value at the L3 level (0, 30) and the highest at its L8 (0.70) level, without registering statistically significant differences regarding the area at the four analyzed levels. The voids were mostly absent or recorded a minimal percentage area (<1%). Cold lateral condensation of gutta-percha has led to a good adaptation of gutta-percha to the root canal wall, with a small amount of sealer, especially to the sections made at 3 mm from the apex. Given the limitations of this study, we noted that the voids were few – observed in the 6 and 8 mm sections – and were negligible in many cases.

Comparative evaluation of push-out bond strength of gutta-percha using different sealers with lateral condensation and thermoplasticized obturation technique: An in vitro study

Aim:

The study aimed to evaluate and compare the push-out bond strength of gutta-percha using AH plus, Endosequence BC, and Roeko seal sealer with lateral condensation and thermoplasticized obturation technique.

Materials and Methods:

Sixty single-rooted premolars were instrumented and samples were randomly assigned into three groups based on the sealer used (Group A-AH Plus, Group B-Endosequence BC, Group C-Roeko Seal) which were further divided into two subgroups-A1, B1, and C1 were obturated by the lateral condensation technique and A2, B2, and C2 using the thermoplasticized technique. Each sample was sectioned horizontally using a diamond disc, representing apical, middle, and coronal thirds, respectively. Root segments were then mounted on an acrylic block, and push-out bond strength of each sample was tested using the universal testing machine.

Statistical Analysis:

One-way ANOVA, Tukey's test, and unpaired t-test.

Results:

For mandibular premolar teeth with a single canal using lateral condensation technique, the highest push-out bond strength was found in the A1 group (7.30 ± 0.61 MPa) at the apical level. While using the thermoplasticized technique, the highest push-out bond strength was found in the B2 group (3.71 ± 0.81 MPa) at the apical level. Overall results showed that the lateral condensation technique showed significantly higher push-out bond strength than thermoplasticized technique (P < 0.028).

Conclusions:

The push-out bond strength of AH Plus sealer was higher than the Endosequence BC sealer and Roeko seal sealer. Lateral condensation technique has shown higher push-out bond strength than the thermoplasticized technique.

The fate of root canals obturated with Thermafil: 10-year data for patients treated in a master's program

OBJECTIVES

Retrospective description of the 10-year success rate of endodontic treatments with Thermafil (TF).

MATERIALS AND METHODS

Patients treated by postgraduate students in an Endodontics Master's Program (2006-2008) were enrolled. All treated root canals were filled with TF and AH Plus. Teeth satisfying the inclusion criteria (206 teeth in 89 patients) were reexamined clinically and radiographically to estimate a 10-year survival and periapical health. Demographic and medical data were registered; collected information included pre-, intra-, and postoperative variables. Teeth were classified as "healthy" (PAI ≤ 2 in absence of signs/symptoms), "endodontically diseased" (presenting at least one of the following: PAI ≥ 3, signs/symptoms, retreated in the course of the follow-up, or extracted for endodontic reasons), or "non-endodontically diseased" (extracted for non-restorable fractures or periodontal disease). For teeth lost during the 10-year follow-up, details and reason of extraction were analyzed. Two PAI-calibrated examiners assessed outcomes blinded to preoperative status. Bivariate and multilevel analyses were performed (α level set at 0.05).

RESULTS

At 10 years, 179 (87%) teeth survived and 27 were extracted: 20 for non-endodontic reasons (excluded from success analysis) and 7 for endodontic reasons (considered "endodontically diseased"). Multilevel analysis revealed that the probability of extraction was increased by the presence of preoperative pain (odds ratio = 6.720; 95% confidence interval, 1.483-30.448) and by maxillary location (odds ratio = 2.950; 95% confidence interval, 1.043-8.347). Concerning periapical status, 159/186 teeth (85%) were assessed as "healthy." Multilevel analysis confirmed that maxillary location (odds ratio = 3.908; 95% confidence interval, 1.370-11.146), presence of flare up (odds ratio = 9.914; 95% confidence interval, 2.388-41.163), and fracture occurrence (odds ratio = 35.412; 95% confidence interval, 3.366-372.555) decreased the odds of healing, respectively.

CONCLUSIONS

After 10 years, teeth filled with Thermafil in a specialist master's program presented a survival and a periapical health comparable to cohorts where root canals were filled with other obturation techniques.

CLINICAL RELEVANCE

Carrier-based techniques provide time savings for clinicians while satisfying clinical quality criteria for the root filling and consequently the clinical outcome.

Clinical studies on core-carrier obturation: a systematic review and meta-analysis

BACKGROUND

This systematic review aimed to evaluate the clinical performance of core-carrier obturation in endodontic treatment.

METHODS

Keywords of "(core carrier OR Thermafil) OR (cold lateral condensation OR lateral condensation) OR (warm vertical condensation OR vertical condensation) AND (obturation OR root canal filling) AND clinical study" were searched for all obtainable publications up to year 2017 in the databases of PubMed, ScienceDirect, EMBASE, Scopus and Web of Science. The success rate, short-term postoperative pain, overfilling and adaptation of core-carrier obturation from clinical studies were selected. Reviews, laboratory studies, animal studies and irrelevant reports were excluded.

RESULTS

1349 relevant articles were identified with 149 duplicated articles removed and 1173 irrelevant articles were excluded after screening. The titles and abstracts of the 19 identified articles were screened in the systematic review. The full texts of remaining articles were retrieved with data extracted for meta-analysis on the success rate, postoperative pain, overfilling and adaptation of obturation. The pooled success rate of core-carrier obturation was 83% (95% CI: 69%-91%). The pooled incidence of 1-day and 7-day short-term postoperative pain were 35% (95% CI: 15%-62%) and 6% (95% CI: 1-35%). The pooled proportion of teeth with overfilling and adequate adaptation of the obturation material were 31% (95% CI: 18%-50%) and 85% (95% CI: 75%-91%), respectively.

CONCLUSIONS

The success rate of endodontic treatment using core-carrier obturation was 83%. Short-term postoperative pain was not uncommon (24%). Most teeth (85%) had adequate adaptation using core-carrier obturation material, but a considerable amount of teeth (31%) had overfilling.

Outcome of secondary root canal treatment filled with Thermafil: a 5-year follow-up of retrospective cohort study

OBJECTIVES

The aim of the present retrospective cohort study was to assess the 5-year outcome and survival of secondary root canal treatments (2°RCT), exploring the influence of pre-, intra-, and post-operative variables.

MATERIALS AND METHODS

One hundred thirty-two endodontically retreated teeth were radiographically and clinically re-examined after 5 years. 2°RCT had been performed during a Masters program following standardized protocols and filled with AH Plus/Thermafil (TF). Pre-, intra-, and post-operative data were collected. The 5-year outcome was blindly evaluated and categorized as healed/diseased on the basis of the periapical index. Bivariate analysis and chi-square test evaluated the association between outcome and 31 demographic/clinical parameters. Multilevel analysis was performed at both patient and tooth level. Statistical significance was calculated at 5% level.

RESULTS

At 5-year evaluation, survival rate was 80% with 7.5% lost for endodontic reasons. Eighty-three percent of the teeth were classified as healed. Multilevel analysis identified significant predictors of increased survival: female gender (p = 0.012), absence of a pre-operative metal post (p = 0.017), conservative apical preparation (diameter size < #35) (p = 0.039), teeth restored with a crown (p = 0.009), and final PAI (after 5 years) ≤ 2 (p = 0.001). Multilevel analysis identified as predictor healing: not being a smoker (p = 0.048) and conservative apical preparation < size #35 (p = 0.037).

CONCLUSIONS

Outcome of 2°RCT filled with Thermafil was successful at 5 years, showing a high rate of survived and healed teeth comparable to that reported previously for other obturation techniques.

CLINICAL RELEVANCE

Present findings confirm 2°RCT as a valid therapeutic option to retain natural teeth.

2016 ASE undergraduate essay competition candidate information

The aim of this review is to discuss the role of medicaments and materials used in teeth undergoing root canal treatment and how they affect the overall prognosis of root canal treated teeth. Irrigants, medicaments and materials play a vital role in RCT. They reduce the overall microbial load within the root canal system, help reduce inter-appointment pain, and induce apexification during RCT of permanent teeth with immature apices. In addition, they also help create a hermetic coronal and periradicular seal to entomb any residual microorganisms within the canals and prevent future ingress of contaminants into the root canal system and subsequent reinfection. Whilst the role of various materials in RCT has been thoroughly investigated, the available literature and longitudinal clinical studies evaluating the affect of such materials on the prognosis of RCT is scarce, and requires further investigation.

Single versus multiple visits for endodontic treatment of permanent teeth

BACKGROUND

Root canal treatment (RoCT), or endodontic treatment, is a common procedure in dentistry. The main indications for RoCT are irreversible pulpitis and necrosis of the dental pulp caused by carious processes, tooth cracks or chips, or dental trauma. Successful RoCT is characterised by an absence of symptoms (i.e. pain) and clinical signs (i.e. swelling and sinus tract) in teeth without radiographic evidence of periodontal involvement (i.e. normal periodontal ligament). The success of RoCT depends on a number of variables related to the preoperative condition of the tooth, as well as the endodontic procedures. This review updates the previous version published in 2007.

OBJECTIVES

To determine whether completion of root canal treatment (RoCT) in a single visit or over two or more visits, with or without medication, makes any difference in term of effectiveness or complications.

SEARCH METHODS

We searched the following electronic databases: Cochrane Oral Health's Trials Register (to 14 June 2016), Cochrane Central Register of Controlled Trials (CENTRAL) (the Cochrane Library, 2016, Issue 5), MEDLINE Ovid (1946 to 14 June 2016), and Embase Ovid (1980 to 14 June 2016). We searched ClinicalTrials.gov and the World Health Organization International Clinical Trials Registry Platform for ongoing trials to 14 June 2016. We did not place any restrictions on the language or date of publication when searching the electronic databases.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and quasi-RCTs of people needing RoCT. We excluded surgical endodontic treatment. The outcomes of interest were tooth extraction for endodontic problems; radiological failure after at least one year, i.e. periapical radiolucency; postoperative pain; swelling or flare-up; painkiller use; sinus track or fistula formation; and complications (composite outcome including any adverse event).

DATA COLLECTION AND ANALYSIS

We collected data using a specially designed extraction form. We contacted trial authors for further details where these were unclear. We assessed the risk of bias in the studies using the Cochrane tool and we assessed the quality of the body of evidence using GRADE criteria. When valid and relevant data were collected, we undertook a meta-analysis of the data using the random-effects model. For dichotomous outcomes, we calculated risk ratios (RRs) and 95% confidence intervals (CIs). For continuous data, we calculated mean differences (MDs) and 95% CIs. We examined potential sources of heterogeneity. We conducted subgroup analyses for necrotic and vital teeth.

MAIN RESULTS

We included 25 RCTs in the review, with a total of 3780 participants, of whom we analysed 3751. We judged three studies to be at low risk of bias, 14 at high risk, and eight as unclear.Only one study reported data on tooth extraction due to endodontic problems. This study found no difference between treatment in one visit or treatment over multiple visits (1/117 single-visit participants lost a tooth versus 2/103 multiple-visit participants; odds ratio (OR) 0.44, 95% confidence interval (CI) 0.04 to 4.78; very low-quality evidence).We found no evidence of a difference between single-visit and multiple-visit treatment in terms of radiological failure (risk ratio (RR) 0.91, 95% CI 0.68 to 1.21; 1493 participants, 11 studies, I² = 18%; low-quality evidence); immediate postoperative pain (dichotomous outcome) (RR 0.99, 95% CI 0.84 to 1.17; 1560 participants, 9 studies, I² = 33%; moderate-quality evidence); swelling or flare-up incidence (RR 1.36, 95% CI 0.66 to 2.81; 281 participants, 4 studies, I² = 0%; low-quality evidence); sinus tract or fistula formation (RR 0.98, 95% CI 0.15 to 6.48; 345 participants, 2 studies, I² = 0%; low-quality evidence); or complications (RR 0.92, 95% CI 0.77 to 1.11; 1686 participants, 10 studies, I² = 18%; moderate-quality evidence).The studies suggested people undergoing RoCT in a single visit may be more likely to experience pain in the first week than those whose RoCT was over multiple visits (RR 1.50, 95% CI 0.99 to 2.28; 1383 participants, 8 studies, I² = 54%), though the quality of the evidence for this finding is low.Moderate-quality evidence showed people undergoing RoCT in a single visit were more likely to use painkillers than those receiving treatment over multiple visits (RR 2.35, 95% CI 1.60 to 3.45; 648 participants, 4 studies, I² = 0%).

AUTHORS' CONCLUSIONS

There is no evidence to suggest that one treatment regimen (single-visit or multiple-visit root canal treatment) is better than the other. Neither can prevent all short- and long-term complications. On the basis of the available evidence, it seems likely that the benefit of a single-visit treatment, in terms of time and convenience, for both patient and dentist, has the cost of a higher frequency of late postoperative pain (and as a consequence, painkiller use).

Theoretical distribution of gutta-percha within root canals filled using cold lateral compaction based on numeric calculus

This study aimed to present a new method based on numeric calculus to provide data on the theoretical volume ratio of voids when using the cold lateral compaction technique in canals with various diameters and tapers. Twenty-one simulated mathematical root canal models were created with different tapers and sizes of apical diameter, and were filled with defined sizes of standardized accessory gutta-percha cones. The areas of each master and accessory gutta-percha cone as well as the depth of their insertion into the canals were determined mathematically in Microsoft Excel. When the first accessory gutta-percha cone had been positioned, the residual area of void was measured. The areas of the residual voids were then measured repeatedly upon insertion of additional accessary cones until no more could be inserted in the canal. The volume ratio of voids was calculated through measurement of the volume of the root canal and mass of gutta-percha cones. The theoretical volume ratio of voids was influenced by the taper of canal, the size of apical preparation and the size of accessory gutta-percha cones. Greater apical preparation size and larger taper together with the use of smaller accessory cones reduced the volume ratio of voids in the apical third. The mathematical model provided a precise method to determine the theoretical volume ratio of voids in root-filled canals when using cold lateral compaction.

Evaluation of Coronal Leakage Following Different Obturation Techniques and in-vitro Evalution Using Methylene Blue Dye Preparation

INTRODUCTION

Coronal and apical leakage still remains one of the most important cause for endodontic failure in spite of the presence of advanced endodontic materials. The cause may attribute to different filling techniques, physical and chemical properties of sealers and presence or absence of smear layer assessment of coronal or apical leakage is used as a research method to compare the sealing ability of different techniques and endodontic materials.

AIM

To compare the coronal bacterial leakage using methylene blue in four different obturation techniques after protaper hand instrumentation.

MATERIALS AND METHODS

Ninety extracted single-rooted teeth were instrumented to an apical preparation size F3 Protaper hand files. Twenty teeth were randomly obturated with lateral compaction, 20 with vertical compaction, 20 with combination of vertical and lateral compaction and 20 with Thermafil. Ten teeth were used for positive and negative controls (five teeth in each group). Teeth were kept in 100% humidity for 90 days, and then subjected coronally to Proteus vulgaris for 21 days to assess bacterial leakage. After bacterial challenge, methylene blue was placed coronally for another 21 days, and then scoring was done according to depth of dye leakage. Chi-square test was done for statistical analysis.

RESULTS

Leakage as observed with combination of vertical and lateral compaction was significantly less than vertical compaction, lateral compaction and thermafil carriers during bacterial challenge. However, when dye was used it also showed statistically significant results with thermafil carriers showing the least leakage in comparison to vertical condensation, lateral condensation and combined groups.

CONCLUSION

The study concludes that two different methods i.e. bacterial and dye leakage revealed considerable variation on the same substrate Thus, due to the presence of variability among the results obtained by two different analytical methods used in the present study, the study emphasizes the need for standardization of methods as the lack of standardization hinders the comparison of different endodontic filling techniques.

In vitro evaluation of carrier based obturation technique: a CBCT study

AIM

The goal of the study was to compare the ability of two different carrier based obturation (CBO) techniques to reach working length and fill in three-dimensions root canal systems, by using CBCT.

MATERIALS AND METHODS

Twenty-six extracted molars were scanned with CBCT and 40 curved canals were selected (between 30° and 90°) and divided in two similar groups (n=20). All canals were prepared up to size 25 taper .06 using nickel-titanium instrumentation. The canals in the Group SC were obturated using Soft-Core obturators (Kerr, Romulus, Mi, USA), while Group TH canals (n= 20) were obturated using Thermafil Endodontic Obturators (Tulsa Dental Products, Tulsa, OK, USA), strictly following manufacturers' instructions for use. The obturations were analyzed by means of CBCT to measure the distance from the apical limit of obturation to the apical foramen and the presence of voids inside root canals.

RESULTS

There was no significant difference between the two groups in the mean distance of the apical extent of the obturation (t test, p>0.05). Overfilling occurred in only 3 cases (2 in Group TH and 1 in Group SC). The percentages of voids in both groups were very low with no significant difference (Z test, p>0.05).

CONCLUSIONS

The two tested CBO techniques showed similar positive results in terms of performance, even if, after checking with verifiers, in most cases the size of the selected Soft-Core obturator was one size smaller than Thermafil.

Treatment outcomes of single-visit versus multiple-visit non-surgical endodontic therapy: a randomised clinical trial

BACKGROUND

Clincians have been providing single-visit and multiple-visit endodontic treatments for their patients. This study aims to compare the success rate, prevalence of postoperative pain and chairside time of single-visit and multiple-visit endodontic treatments.

METHOD

Patients who required primary endodontic treatment in a university dental clinic were randomly allocated to two general dentists for single-visit or multiple-visit treatments using the same materials and procedures. Ni-Ti rotary files were used to prepare the root canals, which were subsequently obturated with a core-carrier technique. The chairside time was recorded. The treated teeth were followed up every 6 months on clinically signs and symptoms including pain, tenderness to percussion, sinus tract, mobility and abscess. Periapical radiographs were taken to assess periapical pathology. Successful treatments were neither clinical signs/symptoms noted nor radiographic periapical pathology found postoperatively.

RESULTS

A total of 220 teeth from patients aged 46.4 ± 14.1 were followed up for at least 18 months. The mean (±SD) follow-up period was 29.4 ± 9.3 months. The success rates of single-visit and multiple-visit treatments were 88.9 and 87.4 %, respectively (p = 0.729, effect size odds ratio = 1.156). Maxillary teeth had odds ratios of 3.16 (95 % CI: 1.33 to 7.46; p = 0.009) and absence of preoperative apical periodontitis had odds ratios of 4.35 (95 % CI: 1.43 to 13.24; p = 0.010) were identified from logistic regression as having a higher success rate. The average chairside times of single-visit and multiple-visit treatments were 62.0 and 92.9 min, respectively (mean difference = -30.9, 95 % CI: -39.4 to -22.4, p < 0.001, effect size odds ratio = -0.996). Single-visit and multiple-visit treatment had no significant difference in the prevalence of postoperative pain within 7 days (21 and 12 %, p = 0.055, effect size odds ratio = 2.061) and after at least 18 months (0.9 and 1.0 %, p > 0.999, effect size odds ratio = 0.879).

CONCLUSIONS

The success rate and prevalence of postoperative pain of single-visit or multiple-visit treatment had no significant difference. The chairside time for single-visit treatment was shorter than multiple-visit treatment.

TRIAL REGISTRATION

Clinical Trials (WHO) ChiCTR-IOR-15006117 registered on 20 March 2015.

A Prospective Randomized Comparative Study of Cold Lateral Condensation Versus Core/Gutta-percha in Teeth with Periapical Lesions

INTRODUCTION

The aim of this study was to compare the outcome of root canal treatment using either Thermafil (TF; Dentsply Maillefer, Ballaigues, Switzerland) or the cold lateral condensation (CLC) obturation technique in teeth with periapical lesions and to investigate the influence on postoperative pain and treatment outcomes.

METHODS

After standardized root canal preparation technique, 112 teeth were obturated with either the TF or the CLC technique during 2 sessions by single operator. Postoperative pain, obturation length, and treatment outcomes were recorded. The teeth were reviewed clinically and radiographically for 2 years.

RESULTS

Although there were no significant differences between the techniques in the incidence of postoperative pain at 24 hours (P > .05), the incidence of pain was significantly higher in the TF group than in the CLC group at 48 hours (P < .05). During the 2-year follow-up period, there was no statistically significant difference in the success rate of the teeth treated with TF (96.4%) in comparison with those treated with CLC (98.2%) (P > .05).

CONCLUSIONS

In this study, the outcome of the root canal treatment of teeth using the TF and CLC techniques revealed that these techniques are useful for root canal obturation.

Incidence of post-obturation pain after single-visit versus multiple-visit non-surgical endodontic treatments

BACKGROUND

Post-obturation pain is frustrating to both patients and dentists. Its incidence may change with the use of contemporary endodontic techniques. This randomised clinical trial aims to compare the incidence of post-obturation pain at one and seven days after single-visit and multiple-visit non-surgical endodontic treatments.

METHODS

Patients who required primary endodontic treatment in the two clinical trial centres in Hong Kong (HK) and in Beijing (PK) were recruited. Three HK dentists and three PK dentists performed endodontic treatments on 567 teeth using the same procedures and materials, either in a single visit or over multiple visits, using either core carrier or cold lateral condensation for obturation.

RESULTS

The attrition rate was 5.1%, and a total of 538 teeth were evaluated. Among these teeth, 232 (43%) were operated in HK, 275 (51%) were treated in a single visit, and 234 (43%) were treated using core carrier obturation. Logistic regression analysis showed that teeth with apical periodontitis (OR = 0.35, 95% CI = 0.21-0.57, p < 0.01) and less pre-operative pain (OR = 1.10, 95% CI = 1.03-1.18, p < 0.01) had lower incidences of post-obturation pain after one day. The incidences of post-obturation pain after one day for single-visit and multiple-visit treatments were 24.7% (68 of 275) and 33.5% (88 of 263), respectively (p = 0.50). The incidences of post-obturation pain after seven days for single-visit and multiple-visit treatments were 4.0% (11 of 275) and 5.3% (14 of 263), respectively (p = 0.47).

CONCLUSIONS

There was no significant difference in the incidences of post-obturation pain after one day and seven days with single-visit or multiple-visit endodontic treatments.

TRIAL REGISTRATION

ChiCTR-IOR-15005989.

Thermocompaction decreases long-term push-out bond strength of methacrylate-based sealers

PURPOSE

The purpose of this study was to evaluate the immediate and long-term bond strengths to root dentin of Epiphany/Resilon and AH Plus/gutta-percha fillings, after using either lateral condensation or Tagger's hybrid thermomechanical compaction techniques.

MATERIALS AND METHODS

Eighty human single-rooted teeth were used. The root canals were prepared by means of hand crown-down technique up to a #45 K-file and irrigation with 1% sodium hypochlorite was performed. Samples were randomly divided into eight (n=10) experimental groups divided according to filling material (gutta-percha/AH Plus and Resilon/Epiphany), obturation technique (Lateral compaction and Tagger's hybrid thermomechanical compaction) and storage time (24 h and 6 months). During storage, the samples were kept at 37°C and 100% humidity. After the two experimental periods, each root was sectioned perpendicular to its long axis into three serial slices and push-out tests were carried out using a universal testing machine. Statistical significant differences were set by ANOVA and Tuckey post-hoc (p<0.05).

RESULTS

Using thermocompaction technique, the samples filled with Epiphany/Resilon decreased significantly the bond strength after a 6 months storage-period (p<0.05) and the ones filled with AH Plus/gutta-percha presented a tendency to lower values of the push-out test, although not statistically significant. For both materials, dentin bond strength of the specimens filled by means of lateral condensation remained stable throughout the experimental periods.

CONCLUSION

Under the limitations of the current study, it can be concluded that the thermocompaction technique and the storage time can influence push-out bond strength when used with methacrylate-based sealers.

Quality of obturation achieved by an endodontic core-carrier system with crosslinked gutta-percha carrier in single-rooted canals

OBJECTIVES

The present study examined the quality of obturation in root canals obturated by GuttaCore, a gutta-percha-based core-carrier system with a cross-linked thermoset gutta-percha carrier, by comparing the incidence of gaps and voids identified from similar canals obturated by cold lateral compaction or warm vertical compaction.

METHODS

Thirty single-rooted premolars with oval-shaped canals were shaped and cleaned, and obturated with one of the three obturation techniques (N=10): GuttaCore, warm vertical compaction or cold lateral compaction. Filled canals were scanned with micro-computed tomography (micro-CT); reconstructed images were analysed for the volumetric percentage of gaps and voids at three canal levels (0-4mm, 4-8mm and 8-12mm from working length). The roots were subsequently sectioned at the 4-mm, 8-mm and 12-mm levels for analyses of the percentage of interfacial gaps, and area percentage of interfacial and intracanal voids, using scanning electron microscopy (SEM) to examine negative replicas of root sections. Data were analysed with parametric or non-parametric statistical methods at α=0.05.

RESULTS

Both micro-CT and SEM data indicated that canals obturated with GuttaCore core-carriers had the lowest incidence of interfacial gaps and voids, although the results were not significantly different from canals obturated by warm vertical compaction. Both the GuttaCore and the warm vertical compaction groups, in turn, had significantly lower incidences of gaps and voids than the cold lateral compaction group.

CONCLUSIONS

Because of the similarity in obturation quality between GuttaCore and warm vertical compaction, practitioners may find the GuttaCore core-carrier technique a valuable alternative for obturation of oval-shaped canals.

CLINICAL SIGNIFICANCE

The quality of obturation achieved by GuttaCore in single-rooted canals is not significantly different from that achieved by warm vertical compaction.

Ability of new obturation materials to improve the seal of the root canal system: a review

New obturation biomaterials have been introduced over the past decade to improve the seal of the root canal system. However, it is not clear whether they have really produced a three-dimensional impervious seal that is important for reducing diseases associated with root canal treatment. A review of the literature was performed to identify models that have been employed for evaluating the seal of the root canal system. In vitro and in vivo models are not totally adept at quantifying the seal of root canals obturated with classic materials. Thus, one has to resort to clinical outcomes to examine whether there are real benefits associated with the use of recently introduced materials for obturating root canals. However, there is no simple answer because endodontic treatment outcomes are influenced by a host of other predictors that are more likely to take precedence over the influence of obturation materials. From the perspective of clinical performance, classic root filling materials have stood the test of time. Because many of the recently introduced materials are so new, there is not enough evidence yet to support their ability to improve clinical performance. This emphasizes the need to translate anecdotal information into clinically relevant research data on new biomaterials.

Influence of the Method in Root Canal Filling Using Active Lateral Compaction Techniques

The aim of this study was to evaluate, by stereomicroscopy and confocal laser microscopy, the influence of different lateral compaction methods for the obturation quality, as well as the time spent for the procedure. Thirty root canals of freshly extracted single-rooted human teeth were prepared with the ProTaper system up to F5 instrument and filled with gutta-percha and AH Plus sealer by the lateral compaction technique. The teeth were divided into 3 groups (n=10) in accordance with the method used for the lateral compaction, as follows: Manual, Mechanical and Ultrasonic. The sealers were stained with rhodamine B dye in a proportion of 0.1% per gram in weight to allow for the analysis under a confocal microscope. During the root filling procedure, the time spent was recorded with a stopwatch. The specimens were stored at 37 °C for 48 h, and then sectioned at 2, 4 and 6 mm from the apex. The percentage of gutta-percha, sealer and void areas were evaluated using a stereomicroscope and sealer penetration perimeter by confocal laser microscope. Statistical analyses were performed using the Kruskall-Wallis and Dunn tests (p<0.05). The mechanical method required a shorter time for the lateral compaction than the manual method (p<0.05). There were no significant differences (p>0.05) for the perimeter of the dentin with sealer penetration among all groups. The mechanical method showed a higher (p<0.05) percentage of gutta-percha and less sealer at the 4 mm section in comparison with the manual method. The ultrasonic group showed intermediate values. The void areas found in the root filling were similar (p>0.05) between the three methods. In conclusion, the fastest lateral compaction was achieved with the mechanical method, and all the methods showed void areas in the root filling.

A clinical trial of cold lateral compaction with Obtura II technique in root canal obturation

INTRODUCTION

The purpose of obturation of the prepared root canal space is to prevent coronal leakage and bacterial contamination and to seal the apex from the periapical tissue fluids. Cold lateral technique has been considered to be a gold standard, however considering its limitations various thermoplasticized gutta-percha techniques have been recommended. This study compares radiographic quality of obturation in molar teeth, obturated with cold lateral condensation and thermoplasticized injectable gutta-percha technique (Obtura II system).

MATERIALS AND METHODS

Sixty patients were equally divided into two groups, Group A obturated with Cold lateral condensation technique and group B with Obtura II. Periapical radiographs were obtained immediately after the obturation using paralleling device method. The radiographs were examined by an observer, who was blinded to the group allocation. Data was compared using χ(2) (Chi square) test and Independent sample t test was used to compare the mean ages.

RESULTS

Both groups were comparable in all respects such as tooth type, preoperative diagnosis and preoperative pain (P>0.05); however, more pre-operative radiolucency cases were allocated to Obtura II (P<0.05). There was no difference between the two groups, both in terms of postoperative voids as well as apical termination of the obturation (P>0.05).

CONCLUSION

Within the limitations of the study, it was found that statistically there was no significant difference between cold lateral and obtura II technique, in terms of post obturation voids and apical termination, as observed in radiographs.

Comparative analysis of carrier-based obturation and lateral compaction: a retrospective clinical outcomes study

The purpose of this retrospective study was to compare the outcome of primary endodontic treatment using a standardized cleaning and shaping technique and obturation with either lateral compaction or carrier-based obturation. Patients received primary endodontic treatment in the predoctoral dental clinic using a standardized cleaning and shaping protocol. All root canals were obturated using AH Plus^TM sealer with lateral compaction of gutta-percha (LC) or carrier-based obturation (CBO). A total of 205 cases met the inclusion criteria. 71 teeth in 60 patients were recalled after 2 years and evaluated both clinically and radiographically by two independent examiners. Success was defined as a lack of clinical symptoms and a normal periodontal ligament space or reduction in size of a previously existing periapical radiolucency. Chi-square and logistic regression were used for statistical analysis with a significance level of P < 0.05. There was no difference in success rates between cases obturated with LC or CBO (P = 0.802); overall success rate was 83%. Molars had a significantly lower success rate (53%) than premolar and anterior teeth (89%) (P = 0.005), irrespective of the obturation technique used. When a standardized cleaning and shaping protocol was used by predoctoral dental students in a controlled university setting, there was no difference in success rates between cases obturated with LC or CBO.

Prevalence of Enterococcus faecalis in saliva and filled root canals of teeth associated with apical periodontitis

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.

Fracture resistance of root filled premolar teeth restored with direct composite resin with or without cusp coverage

AIM

To evaluate the fracture resistance and fracture patterns of root filled maxillary first premolar teeth (with mesio-occlusal cavity preparation) restored with several composite restoration designs.

METHODOLOGY

One hundred extracted sound human maxillary first premolars were randomly divided into five groups. Group 1 remained untreated (negative control). Conventional root canal treatment with additional mesial-occlusal cavity preparation was carried out on teeth in groups 2-5. In group 2, the teeth were restored intra-coronally with direct composite resin (positive control). In group 3, the palatal cusps of the teeth were reduced, and the cavities were restored with composite resin covering the palatal cusp (partial coverage). In group 4, the buccal and palatal cusps along with the distal marginal ridges were reduced; the cavities and cusps were restored with composite resin (conventional full coverage). In group 5, the buccal and palatal cusps were reduced but the distal marginal ridges were conserved. The cavities and the cusps were restored with composite resin (modified full coverage). All teeth were subjected to a progressive compressive loading parallel to their longitudinal axis until fracture. Fracture resistance was analysed using the one-way ANOVA and Fisher's LSD test. Fracture patterns were analyzed with chi-square test. The significance level was set at 0.05.

RESULTS

The fracture resistance (mean ± SD) of groups 1-5 was 1131 ± 207N, 904 ± 184N, 927 ± 224N, 1095 ± 289N and 1085 ± 243N, respectively (groups 1, 4, 5 > groups 2, 3; P = 0.004). Cusp fractures were recorded as the fracture pattern in 20 (100%), 19 (95%), 16 (80%), 8 (40%) and 12 (60%) premolars in groups 1-5, respectively (groups 1, 2 > groups 4, 5; group 3 > group 4; P < 0.001).

CONCLUSIONS

When direct composite resin was used to restore root filled maxillary first premolar teeth involving a proximal surface, those restored with full-coverage designs had greater fracture resistance.

Incidence of dentinal defects after root canal filling procedures

AIM

To compare the incidence of dentinal defects (cracks and craze lines) after root canal preparation, lateral compaction and continuous wave compaction of gutta-percha and AH26 sealer.

METHODOLOGY

Two hundred mandibular premolar teeth were divided into four groups with similar average canal diameters (n=50). One group was left untreated and served as the control. The other three groups were prepared with ProTaper rotary instruments up to size F4. After preparation, one group was left unfilled while two groups were filled with gutta-percha and AH26 using either lateral compaction or the continuous wave technique. Roots were then sectioned at 3, 6 and 9 mm from the apex and inspected under a microscope. The appearance of dentinal defects was noted as well as the minimum and mean remaining dentine thickness. Chi-square tests were performed to compare the incidence of dentinal defects between the groups (α=0.05), and Pearson correlation test was performed to check the correlation between defects and root level or remaining dentine thickness.

RESULTS

The unprepared control group had no dentinal defects. The other groups exhibited significantly more defects than the unprepared group (P<0.05). There was no difference in the incidence of defects between the two filling techniques. There was no correlation between the appearance of defects and level of the root or remaining dentine thickness.

CONCLUSIONS

In extracted teeth, dentinal defects were observed in roots filled with gutta-percha and AH26 using the lateral compaction and continuous wave techniques.

Fluid-transport evaluation of lateral condensation, ProTaper gutta-percha and warm vertical condensation obturation techniques

The purpose of this study was to compare the microleakage of four obturation techniques (lateral condensation, lateral condensation of ProTaper Gutta-percha, single ProTaper Gutta-percha and warm vertical condensation) over a 3-month period. A fluid-transport model was used to measure microleakage. Sixty human-extracted teeth, divided into four groups, were prepared with ProTaper rotary instruments before the root canals were filled by one of the four examined techniques. All groups were obturated using Sultan as a root canal sealer. Microleakage was measured 7 days, 1 month and 3 months after the procedures. There were no statistically significant differences between the four groups at any of examination points (P > 0.05). The leakage was increased in all obturation techniques over the 3-month period.

Root Canal Treatment Using Thermoplasticized Carrier Condensation Technique

BACKGROUND

The management of pulpally and apically infected teeth has evolved into a modality of conservation with predictable degree of success. Root canal treatment often requires protracted chairside time. A new technique involving placement of thermoplasticized core carrier obturators was compared with conventional lateral condensation technique.

METHODS

A prospective, comparative, in-vivo cohort study was carried out on randomly selected 100 patients visiting a tertiary care centre from July 2005 to July 2007, for primary, non-surgical conservative management of teeth requiring root canal treatment. Two groups of fifty cases each were managed with lateral condensation and thermoplasticized core carrier obturation techniques. Outcome variables were rate of obturation and failure rates as assessed by clinical and radiological evaluation.

RESULT

The time taken in case of lateral condensation of maxillary central incisor was 17.30 ± 3.373 minutes and 28.07 ± 2.586 minutes in case of mandibular molar. In the thermoplasticized carrier condensation technique, for the central incisors it took 13.00 ± 1.376 minutes and 21.07 ± 2.463 minutes for mandibular molars. The mean rank value for time taken for obturation as per Mann Whitney U test (p < 0.01) were 27.88 for maxillary incisor and 44.73 for mandibular molar in the lateral condensation technique and 13.13 and 16.27 respectively for thermoplasticized gutta percha carrier condensation. The values were statistically significant. With 16% and 14% cases having unsatisfactory filling as evaluated by post filling radiograph, Chi square test two tailed p value was 0.6836 and there was no statistically significant difference between the two groups. An absolute failure rate of 10% was seen in lateral condensation group and 6% in thermo-plasticized carrier condensation group. Fisher exact 2-tailed p value was 0.71 and the difference in failure rate was not statistically significant.

CONCLUSION

Root canal obturation by thermoplasticized core carrier condensation technique is an effective alternative to conventional lateral condensation technique in terms of quick and successful outcome.

Parallel post-space preparation in different tooth types ex vivo: deviation from the canal centre and remaining dentine thickness

AIM

To determine the deviation of parallel-sided twist-drills during post-channel preparation and relate this to tooth type and position.

METHODOLOGY

Human teeth with single root canals were selected: maxillary second premolars (group i); maxillary lateral incisors (group ii); mandibular canines (group iii); mandibular first premolars (group iv; all groups n = 16). The teeth were reduced to 17 mm length by sectioning the crown, and the root canals prepared and filled. Microradiographs were made in two directions. The teeth were individually embedded in a gypsum jaw and placed in a phantom head. Two operators performed parallel post-space preparation (12 mm length, 1.25 mm diameter) to the following protocol: gutta-percha removal with Gates Glidden drills numbers 2 and 3 and post-space enlargement with parallel drills numbers 3, 4 and 5, consecutively. Subsequently, microradiographs were re-exposed. The original and post-operative microradiographs were digitized and superimposed, and deviation of the post-space from the filled canal and remaining dentine thickness measured.

RESULTS

Overall, the mean deviation was 0.07 mm to the mesial (95% CI: 0.01-0.12), and 0.27 mm to the buccal (95% CI: 0.18-0.35). Group ii had significantly more buccal deviation than other groups (P = 0.004-0.008). A remaining dentine thickness of <0.5 mm occurred 16 times in 14 teeth, and of <1 mm occurred 97 times in 52 teeth.

CONCLUSIONS

Deviation during parallel post-preparation was common, predominantly in mesial and buccal directions, especially in maxillary incisors. This deviation increased the risk of perforation considerably.

A quantitative evaluation of sealing ability of 4 obturation techniques by using a glucose leakage test

OBJECTIVE

The aim of this study was to evaluate the sealing ability of 4 different obturation techniques by using a glucose leakage test.

STUDY DESIGN

Eighty extracted single-rooted maxillary incisors were selected for the study. The teeth were decoronated and the root canals prepared using ProFile rotary instruments to an apical dimension of size 40 (0.06 taper). The specimens were then randomly divided into 4 experimental groups (n = 15) and filled with gutta-percha and sealer by using either cold lateral compaction, warm vertical compaction, Thermafil, or the E & Q Plus system. Another 10 teeth each served as the positive and negative controls. A glucose leakage model was used for quantitative evaluation of the coronal-to-apical microleakage at 24 hours, 1, 2, 3, 5, 8, and 12 weeks.

RESULTS

No significant difference in the cumulative amount of leakage was found among the 4 groups at 24 hours and 1 week (Kruskal-Wallis test, P > .05). Lateral compaction showed significantly more leakage than the other 3 techniques at longer intervals (Mann-Whitney U test, P < .008). No significant difference was found between vertical compaction, Thermafil, and E & Q Plus at all observation times.

CONCLUSIONS

Warm vertical compaction, Thermafil, and the E & Q Plus system showed a better sealing result than cold lateral compaction of gutta-percha at extended observation periods. The glucose leakage method used in this study was able to provide a nondestructive, quantitative, and long-term evaluation of the sealing ability of root canal fillings.

The influence of smear layer in lateral channels filling

This in vitro study evaluated the ability of a warm gutta-percha obturation system Thermafil to fill lateral channels in presence/absence of smear layer. Forty single-rooted extracted human teeth were randomly divided into two groups for which different irrigation regimens were used: group A, 5 ml of 5% NaOCl + 2.5 ml of 3.6% H(2)O(2); group B, 5 ml of 5% NaOCl 5% + 2.5 ml of 17% ethylenediamine tetraacetic acid. A conventional crown-down preparation technique was employed. Obturation was performed using epoxy resin-based cement (AH Plus) and a warm gutta-percha plastic carrier system (Thermafil). Specimens were cleared in methyl salicylate and analyzed under a stereomicroscope to evaluate the number, length, and diameter of lateral channels. Lateral channels were identified in both groups at medium and apical thirds. Additional samples were prepared for scanning electron microscopy inspection to confirm the presence of smear layer in group A, and the absence of smear layer in group B. All lateral channels resulted filled in both groups. No statistically significant differences regarding number, length, and diameter were observed between the two groups. Smear layer did not prevent the sealing of lateral channels.

Leakage along apical root fillings with and without smear layer using two different leakage models: a two-month longitudinal ex vivo study

AIM

To compare two different experimental models when measuring leakage along root fillings with or without smear layer.

METHODOLOGY

One hundred and twenty single-rooted teeth were prepared to size 50 and allocated to two groups: fluid transport model (n = 60) and glucose penetration model (n = 60). The roots in each group were divided into three subgroups of 20 teeth each. Smear layer was left in place in group 1 but removed in groups 2 and 3. In groups 1 and 2 canals were filled with laterally compacted gutta-percha cones and AH 26. Group 3 was laterally compacted with Resilon cones and Epiphany sealer. The coronal portion of the filling was removed to assure only 4 mm of filling remained in the canal. Leakage of glucose was evaluated by measuring its concentration once a week for a total period of 56 days using a glucose penetration model. Fluid transport was evaluated by measuring the movement of an air-bubble using a fluid transport model, 1 and 8 weeks after canal filling. Differences between the groups in glucose concentrations and fluid transport were statistically analysed with the Kruskal-Wallis and the Mann-Whitney tests. The level of significance was set at alpha = 0.05.

RESULTS

Glucose penetration was significantly different between the three groups after the first 8 days (P < 0.05). Resilon leaked the most throughout the experiment period. No significant difference (P > 0.05) existed between the two gutta-percha groups at all time intervals (Mann-Whitney test). In the fluid transportation model, no statistically significant differences were observed between all three experimental groups (P > 0.05) at either 1 or 8 weeks after filling (Kruskal-Wallis test).

CONCLUSIONS

Under the conditions of this study, the glucose penetration model was more sensitive in detecting leakage along root fillings. Removing the smear layer before filling did not improve the sealing of the apical 4 mm of filling. Resilon allowed more glucose penetration but the same amount of fluid transport as the gutta-percha root fillings.

Sealer area associated with cold lateral condensation of gutta-percha and warm coated carrier filling systems in canals prepared with various rotary NiTi systems

AIM

To compare the area of sealer surrounding root fillings completed by two coated carrier systems (Thermafil Obturator and System GT Obturator) and the cold lateral compaction technique, following root canal preparation with two different NiTi rotary systems (Profile ISO and System GT).

METHODOLOGY

Sixty extracted human mandibular premolars were instrumented with ProFile ISO 0.06 taper and System GT instruments (n = 30 each). The teeth were divided into four subgroups (n = 15) for filling as following: group 1: ProFile + Thermafil Obturator, group 2: ProFile + Cold Lateral Compaction, group 3: System GT + GT Obturator, and group 4: System GT + Cold Lateral Compaction. In all groups the canals were prepared to a final size of 40, 0.06 taper in accordance with the manufacturer's instructions and Topseal was used as a sealer. Horizontal sections were obtained every 1 mm up to 12 mm from the apical foramen. Sections were digitally photographed under a stereomicroscope and the images were transferred to an IBM-compatible PC for image analysis. The cross-sectional area of the root canal and the area filled by sealer were calculated for each section and compared statistically both at all levels and by grouping the data as apical, middle and coronal segments; using the Kruskal-Wallis test with Bonferroni correction and chi-square tests (P = 0.05).

RESULTS

In the apical third (1-4 mm), the GT Obturator (group 3) had significantly less area of sealer (P < 0.05), while the difference between groups 1 and 2 was not significant (P > 0.05). For the middle and coronal thirds, both coated-carrier systems had significantly less area of sealer compared with their laterally compacted counterparts (P < 0.05).

CONCLUSIONS

With the combined use of ProFile + Thermafil Obturator and System GT + GT Obturator, significantly less area of sealer occurred than that achieved with both NiTi preparation systems followed by cold lateral compaction.