Influence of Demographic Factors on the Prevalence of a Second Root Canal in Mandibular Anterior Teeth - A Systematic Review and Meta-Analysis of Cross-Sectional Studies Using Cone Beam Computed Tomography.

OBJECTIVE: The purpose of this systematic review was to assess the influence of population demographic characteristics on the prevalence of a second canal in mandibular anterior teeth. DESIGN: Four electronic databases and five peer-reviewed journals were searched from May 2018 to September 2019 for prevalence studies using cone-beam computed tomographic imaging on second canal morphology in mandibular anterior teeth. The identified studies were subjected to a hand search of bibliographic references followed by contact with the authors. Full text analysis and critical appraisal (JBI) was undertaken on 40 papers by 2 evaluators. Sixteen studies were included into a meta-analysis. Forest plots with proportion and odds ratios with a 95% confidence interval were calculated. Meta-regression was performed in order to identify possible sources of heterogeneity. RESULTS: The 16 selected studies presented an average JBI score of 77.7% and revealed data from 40,784 mandibular anterior teeth (14,278 central incisors, 14,433 lateral incisors, and 12,073 canines). The overall prevalence of a second canal for central incisors, lateral incisors and canines was 20.4% (15.0%-25.7% CI 95%), 25.3% (20.0%-30.7% CI 95%) and 5.9% (4.1%-7.7% CI 95%), respectively. Males showed significantly higher odds of having a second canal for both incisors (p < 0.05). East Asia studies presented lower proportions of a second canal in mandibular anterior teeth (p < 0.05). CONCLUSIONS: The overall prevalence of a second canal in the mandibular central and lateral incisors and canines was 20.4%, 25.3% and 5.9%, respectively. Meta-analysis calculation revealed gender and patient geographic origin as possible confounding factors of the proportion outcomes.

Management of progressive apical root resorption 13 years after dental trauma and primary endodontic treatment.

Many studies have focused on the search for a restorative material with good sealing properties and biocompatibility for treatment of teeth with open apices and necrotic pulps, which can result from periradicular disease and root resorption. Mineral trioxide aggregate (MTA) has exhibited promising clinical results in retrograde fillings and pulpotomies as well as for treatment of root perforations, root resorptions, incomplete root formations, and pulpal necrosis. This case report describes the management of a progressive apical root resorption in a previously traumatized tooth that had been endodontically treated. Five years of clinical and radiographic follow-up demonstrated the clinical efficacy of MTA in limiting the inflammatory resorptive process and promoting apexification and regeneration of periradicular tissue.

Effectiveness of different formulations of Endo-PTC to promote root canal cleaning.

CONTEXT: Endo-PTC are used during endodontic treatment; however, until now no study evaluated the cleaning of dentin walls after use of different Endo-PTC formulations. AIMS: The aim of this study was to assess qualitatively, by means of scanning electron microscopy (SEM) images, the cleaning of dentin walls of root canals after chemomechanical preparation (CMP) using Endo-PTC cream and Endo-PTC light associated to 2.5% sodium hypochlorite and 17% ethylenediamine tetraacetate (EDTA). MATERIALS AND METHODS: Forty single-rooted human maxillary central incisors with straight canals and fully formed apex were selected. The specimens were randomly divided into four groups depending on the type of Endo-PTC and the final rinse with 17% EDTA. After CMP, all specimens were sectioned and processed for observation of the apical thirds by using SEM. Three calibrated evaluators attributed scores to each specimen. STATISTICAL ANALYSIS USED: The differences between irrigation protocols were analyzed with Kruskal-Wallis test followed by Bonferroni adjustment for multiple comparisons. The significance level was set at α = 0.05. RESULTS: The use of Endo-PTC cream or Endo-PTC light did not influence the smear-layer (SL) removal (P > 0.05). When EDTA were used, it was obtained the best cleaning results with no significant difference between the substances (P < 0.05). CONCLUSIONS: It can be concluded that EDTA is essential to promote SL removal which was not affected by the type of Endo-PTC formulation.

Assessment of coronal leakage of a new temporary light-curing filling material in endodontically treated teeth.

INTRODUCTION: The aim of this study was to evaluate the sealing ability of a new temporary filling material X-Temp LC (DFL, São Paulo, SP, Brazil) compared with that obtained for Coltosol (Vigodent, Rio de Janeiro, RJ, Brazil) and Vitro Fill (DFL, Rio de Janeiro, RJ, Brazil), using a dye penetration test. METHODS: Standard endodontic access cavities were prepared in 75 human premolars. The teeth were divided into five groups (n = 15 for each group), including a positive (no sealing of access cavity) and a negative control (Filtek Z350 XT, 3M, São Paulo, SP, Brazil). In the experimental groups, the access cavities were sealed with one of the three tested materials. After that, the teeth were immersed in 10% Indian ink for 14 days. The teeth were then rinsed, dried, sectioned in bucco-lingual direction and evaluated under a stereomicroscope using scores for dye penetration. Data were analyzed using Kruskall-Wallis and Student-Newman-Keuls tests (α =0.05). RESULTS: Positive control sections exhibited complete dye penetration and negative control had no specimen showing marginal leakage. X-Temp LC and Coltosol showed similar results, with no statistical difference between them. Vitro Fill exhibited the highest dye penetration among the experimental groups. CONCLUSION: The results of this in vitro study suggest that all temporary restorative materials exhibit some degree of marginal leakage. X-Temp LC and Coltosol, however seal better than Vitro Fill glass ionomer cement.

Micro-computed tomography and bond strength analysis of different root canal filling techniques.

INTRODUCTION: The aim of this study was to evaluate the quality and bond strength of three root filling techniques (lateral compaction, continuous wave of condensation and Tagger's Hybrid technique [THT]) using micro-computed tomography (CT) images and push-out tests, respectively. MATERIALS AND METHODS: Thirty mandibular incisors were prepared using the same protocol and randomly divided into three groups (n=10): Lateral condensation technique (LCT), continuous wave of condensation technique (CWCT), and THT. All specimens were filled with Gutta-percha (GP) cones and AH Plus sealer. Five specimens of each group were randomly chosen for micro-CT analysis and all of them were sectioned into 1 mm slices and subjected to push-out tests. RESULTS: Micro-CT analysis revealed less empty spaces when GP was heated within the root canals in CWCT and THT when compared to LCT. Push-out tests showed that LCT and THT had a significantly higher displacement resistance (P<0.05) when compared to the CWCT. Bond strength was lower in apical and middle thirds than in the coronal thirds. CONCLUSIONS: It can be concluded that LCT and THT were associated with higher bond strengths to intraradicular dentine than CWCT. However, LCT was associated with more empty voids than the other techniques.

Lateral radiographic technique: an alternative approach for anterior teeth.

AIM: To describe the lateral radiographic technique, its use and indication. BACKGROUND: The clinician's difficulty in performing the correct diagnosis for some endodontic situations sometimes leads to a compromised treatment of some teeth. Considering this, an alternative radiographic technique for anterior teeth (lateral radiographic technique - LRT) may be used to help endodontic diagnosis. TECHNIQUE: This technique use a periapical radiographic film or sensor that is placed vertically in the anterior portion of maxilla or mandible and with the beam passing perpendicular to the radiographic film its possible to evaluate the possibility of a fenestration on the buccal cortical bone plate; differentiate overextension and overfilling; indentify root fractures; confirm the presence and location of an instrument in the root canal system; and assess the treatment of root perforations. CONCLUSION: LRT is an easy and cheap technique that can be used to help in anterior teeth diagnosis. CLINICAL SIGNIFICANCE: Considering that LRT is easy to perform and available at low cost, it could be utilized more by clinicians in the dental office in order to quickly assist in diagnosis. As a complimentary radiographic examination for anterior teeth, it could become a useful supplement to aid the clinical practice.