Evaluation of changes in root canal length and accuracy of the electronic apex locator during different stages of endodontic treatment and retreatment.

This study evaluated changes in the root canal length (RCL) and the accuracy of the electronic apex locator (EAL) during the different stages of endodontic treatment and retreatment. Fifty-six mesial root canals of mandibular molars were selected. The actual root canal length (AL) of the canals was obtained by inserting a size 15 hand file up to the apical foramen, under magnification. The electronic lengths were obtained at the "APEX" mark of Root ZX II, using an alginate model. Both measurements were performed at three different stages of the initial root canal treatment-unflared, flared, and concluded-and at two stages of retreatment, after achieving patency and repreparation. Data were statistically analyzed and the significance level established was 5%. All stages produced a significant reduction in the AL (p < 0.05). The greatest variation was observed between the unflared-flared stages (0.2 mm) and between concluded-patency stages (0.09 mm), with no difference between them (p > 0.05). The accuracy of Root ZX II was negatively affected after achieving patency, presenting statistically significant difference compared to the other stages (p < 0.05). A significant reduction in the RCL was observed along the different stages of endodontic treatment and retreatment. The EAL was accurate to measure the root canals in most stages, except after achieving patency for endodontic retreatment. Determining and monitoring the RCL is an essential step towards a favorable prognosis, since it reduced along the different stages evaluated. Root ZX II was not accurate for endodontic retreatment.

Prevalence of postoperative pain after endodontic treatment using low and high concentrations of sodium hypochlorite: a systematic review and meta-analysis.

OBJECTIVES: To determine the prevalence of postoperative pain after endodontic treatment using low (LC) and high (HC) concentrations of sodium hypochlorite (NaOCl). MATERIALS AND METHODS: Six databases and the grey literature were searched to identify randomized clinical trials that evaluated postoperative pain after endodontic treatment using NaOCl. NaOCl concentrations were dichotomized into 'LC' (0.5% to 3%) and 'HC' (≥ 5%) and a proportion meta-analysis was applied to determine the postoperative pain prevalence: overall and according to pain intensity and postoperative time. The prevalence of patients using pain control medication was also determined. A significance level of 5% and a random effect model were applied for data analysis. Between-study heterogeneity was assessed by I2 index. Risk of bias (RoB) was assessed using the Cochrane Risk-of-Bias 2.0 tool. The certainty of evidence was assessed using the GRADE approach. RESULTS: Ten studies were included in the review and eight in the meta-analysis. The overall prevalence of postoperative pain was 45% in LC and 39% in HC. The prevalence of pain in LC and HC after 24 h was 25% and 40%, respectively. After 48 h, the prevalence decreased to 10% in LC and 25% in HC. 'Absent pain' was the most prevalent score. The prevalence of patients who used medication was 9% in LC and 15% in HC. Three studies were classified as 'high RoB', five as 'low RoB', and two as 'some concerns'. The certainty of evidence was very low. CONCLUSIONS: The overall prevalence of postoperative pain after endodontic treatment using LC and HC of NaOCl was 45% and 39%, respectively. CLINICAL RELEVANCE: Postoperative pain is common after endodontic treatment using NaOCl, but tends to decrease over time.

Association between sella turcica bridging and impacted maxillary canines.

Changes in sella turcica (ST) development may be associated with impaction of the permanent canine teeth. Calcification of the interclinoid ligament, which forms a bridge between the anterior and posterior clinoid processes of the sphenoid bone, has been termed ST bridging. The aim of this study was to evaluate whether an association exists between ST bridging and the presence of impacted maxillary canines (IMCs) in a Brazilian population. In this case-control study, 2 blinded and calibrated examiners measured the length (interclinoidal distance), depth, and diameter of the ST on cephalometric radiographs of 64 adults divided into a case group with IMCs (n = 32) and a control group without IMCs (n = 32). The degree of calcification was established as no (class I), partial (class II), or complete (class III) calcification. A t test was used to compare ST dimensions between the groups, and a chi-square test was used to analyze the association between the degree of calcification and the groups. The association between ST bridging and IMC was estimated by means of logistic regression analysis (α = 0.05). The study findings showed that ST length in the case group was shorter than that in the control group (P = 0.042; t test), and the length was shorter in men than in women (P = 0.038; t test). The ST bridging frequency was higher in the case group (P = 0.03; chi-square test), and there was no difference between men and women. The presence of ST bridging might be associated with increased odds of IMCs (P < 0.01; adjusted odds ratio = 5.92). In this patient sample, the occurrence of IMCs was positively associated with the presence and severity of ST bridging.

Endodontic therapy in primary teeth: a bibliometric analysis of the 100 most-cited papers.

The purpose of this review was to identify and analyze the main characteristics of the 100 most-cited papers in the field of endodontic therapy in primary teeth. A search for the most-cited articles was conducted in the Clarivate Analytics Web of Science 'Core-Collection' (WoS-CC) database up to December 2020. Papers were ranked in descending order, by number of citations, and each paper was matched with the citation count on Scopus and Google Scholar. Two independent reviewers selected the most-cited papers and analyzed it according to the number and density of citations, year and journal of publication, authors, countries and contributing institutions, study design, topic of the paper, and keywords. Spearman's correlation and Poisson regression were used to determine associations between the number of citations and study characteristics. The citation count varied from 15 to 135 (WoS-CC), 8 to 141 (Scopus), and 14 to 317 (Google Scholar). Of the 306 contributing authors, most paper contributions were from Sakai VT, Oliveira TM, and Machado MAAM (5 each). Most of the papers originated from the USA (n=21) and Brazil (n=18). Randomized trials were the most common study design (n=32), and "pulpotomy" was the most frequently used keyword (n=35). Poisson regression showed that the number of citations decreased by 1.5% each year, and increased by 9.7% for each unit of impact factor. This bibliometric analysis highlighted papers, authors, and institutions that have contributed to endodontic therapy in primary teeth. Common terms of interest in this research area was also identified, representing the first bibliometric analysis on this subject.

Association between Orthodontic Force and Dental Pulp Changes: A Systematic Review of Clinical and Radiographic Outcomes.

INTRODUCTION: Orthodontic force triggers a sequence of biological responses that can affect dental pulp. The aim of this study was to systematically evaluate the clinical and radiographic findings of orthodontic force application on dental pulp. METHODS: Two reviewers comprehensively and systematically searched 6 electronic databases (Latin American and Caribbean Health Sciences [LILACS], Embase, Cochrane Library, MEDLINE/PubMed, Scopus, and Web of Science) and the gray literature (Google Scholar, OpenGrey, and ProQuest) until April 2021. According to the PICOS criteria, randomized clinical trials and observational studies that evaluated clinical or radiographic findings compatible with dental pulp changes due to orthodontic force were included. Studies in open apex or traumatized teeth, case series or reports, and laboratory-based or animal studies were excluded. The Newcastle-Ottawa Scale and Cochrane Risk of Bias 2.0 tool were used to determine the risk of bias assessment. The overall certainty level was evaluated with the Grading of Recommendations, Assessment, Development and Evaluations tool. RESULTS: Twenty-six studies were included. Among the clinical findings, orthodontic force promoted an increased pulp sensibility response and decreased pulp blood flow. Changes in pulp cavity volume and increased incidence of pulp stones were the radiographic findings observed. The studies presented a moderate risk of bias for most of the domains. The certainty of the evidence was considered very low. CONCLUSIONS: Orthodontic force promoted changes in the dental pulp, generating clinical and radiographic findings. It is crucial to know these changes so that orthodontic mechanics can be safely performed. The clinician has effective noninvasive methods to assess the health and possible pulp changes during orthodontic treatment.

Endodontic therapy in primary teeth: a bibliometric analysis of the 100 most-cited papers

Abstract: The purpose of this review was to identify and analyze the main characteristics of the 100 most-cited papers in the field of endodontic therapy in primary teeth. A search for the most-cited articles was conducted in the Clarivate Analytics Web of Science 'Core-Collection' (WoS-CC) database up to December 2020. Papers were ranked in descending order, by number of citations, and each paper was matched with the citation count on Scopus and Google Scholar. Two independent reviewers selected the most-cited papers and analyzed it according to the number and density of citations, year and journal of publication, authors, countries and contributing institutions, study design, topic of the paper, and keywords. Spearman's correlation and Poisson regression were used to determine associations between the number of citations and study characteristics. The citation count varied from 15 to 135 (WoS-CC), 8 to 141 (Scopus), and 14 to 317 (Google Scholar). Of the 306 contributing authors, most paper contributions were from Sakai VT, Oliveira TM, and Machado MAAM (5 each). Most of the papers originated from the USA (n=21) and Brazil (n=18). Randomized trials were the most common study design (n=32), and "pulpotomy" was the most frequently used keyword (n=35). Poisson regression showed that the number of citations decreased by 1.5% each year, and increased by 9.7% for each unit of impact factor. This bibliometric analysis highlighted papers, authors, and institutions that have contributed to endodontic therapy in primary teeth. Common terms of interest in this research area was also identified, representing the first bibliometric analysis on this subject.

Effect of orthodontic force on dental pulp histomorphology and tissue factor expression.

OBJECTIVES: To evaluate the effects of orthodontic force on histomorphology and tissue factor expression in the dental pulp. MATERIALS AND METHODS: Two reviewers comprehensively and systematically searched the literature in the following databases: Latin American and Caribbean Health Sciences, Embase, Cochrane, PubMed, Scopus, Web of Science, and Grey literature (Google Scholar, OpenGrey, and ProQuest) up to September 2020. According to the Population, Intervention, Comparison, Outcomes, Studies criteria, randomized clinical trials (RCTs) and observational studies that evaluated the effects of orthodontic force on dental pulp were included. Case series/reports, laboratory-based or animal studies, reviews, and studies that did not investigate the association between orthodontic force and pulpal changes were excluded. Newcastle-Ottawa Scale and Cochrane risk-of-bias tool were used to assess the risk of bias. The overall certainty level was evaluated with the Grading of Recommendations Assessment, Development and Evaluation tool. RESULTS: 26 observational studies and five RCTs were included. A detailed qualitative analysis of articles showed a wide range of samples and applied methodologies concerning impact of orthodontic force on the dental pulp. The application of orthodontic force seems to promote several pulpal histomorphological changes, including tissue architecture, cell pattern, angiogenesis, hard tissue deposition, inflammation, and alteration of the expression levels of 14 tissue factors. CONCLUSIONS: Although the included articles suggest that orthodontic forces may promote histomorphological changes in the dental pulp, due to the very low-level of evidence obtained, there could be no well-supported conclusion that these effects are actually due to orthodontic movement. Further studies with larger samples and improved methods are needed to support more robust conclusions.

Influence of different endodontic sealers on bond strength of fiber posts to weakened roots after resin restoration.

OBJECTIVES: To assess the influence of different sealers used in root canal filling, in terms of bond strength (BS) to dentin, after restoration of weakened roots using resin composite (RC) and fiber posts. MATERIAL AND METHODS: Roots of 39 maxillary incisors were used. After root canal preparation, root dentin was flared to produce a space between fiber post and root canal walls. The root canals were randomly distributed into three groups (n = 13), according to the sealer used: Endofill, AH Plus, and Acroseal. After removing the filling material to a depth of 12 mm, the flared roots were adhesively restored using RC. Posts were cemented and, after 24 h, roots were sectioned transversely producing 1-mm-thick slices. The slices from 30 roots were used for push-out test, and failure modes were noted. The remaining slices were analyzed by scanning electron microscopy (SEM). RESULTS: Statistical analysis by 2-way ANOVA showed a significant difference among sealers (p = 0.001) and among root regions (p < 0.001). The BS mean of Endofill was lower and significantly different from the others. Overall, the coronal region presented higher BS mean values, followed by the middle and apical regions of the reinforced roots. The most frequent failure type was the adhesive failure between RC and dentin. SEM analysis showed the formation of a hybrid layer and many tags in the coronal and middle regions, while the apical region exhibited remnants of the endodontic sealers in all groups. CONCLUSIONS: AH Plus and Acroseal sealer groups presented similar results, and the Endofill sealer negatively affected the BS of fiber post to restored root dentin. CLINICAL RELEVANCE: Weakened dentin walls are often found in teeth undergoing endodontic treatment, so the sealer used must allow or at least not interfere the bonding between restorative materials and root dentin.

A second attempt at pulp revascularisation on an immature traumatised anterior tooth: a case report with two-year follow-up.

This report describes the second attempt at pulp revascularisation, using an association between 2% chlorhexidine (CHX) and calcium hydroxide (CH) as intracanal dressing, in an immature traumatised anterior tooth with pulp necrosis. A 21-year-old woman complained of pain and dental crown darkening of a permanent maxillary right central incisor. Her medical records presented a history of dental trauma, and at age 15, the first attempt at revascularisation was performed, using triple antibiotic paste (TAP) as the intracanal dressing. Recent radiographs then showed a periapical lesion associated with an immature root, which demonstrated the failure of the first attempt. The second pulp revascularisation was performed, using an association between CHX and CH as intracanal medication. The case was followed up for 24 months. Observations showed evidence of root development, dentinal wall thickening and periapical healing. In this case, the association between CHX and CH showed favourable results as an intracanal medication.