Tricalcium silicate cement sealers: Do the potential benefits of bioactivity justify the drawbacks?

BACKGROUND: Grossman described the ideal properties of root canal sealers. The International Organization for Standardization and American National Standards Institute and American Dental Association have codified some of his requirements in ISO 6876 and ANSI/ADA 57, respectively. In this narrative review, the authors combined the ideal Grossman properties and requirements of these standards, emphasizing the newer tricalcium silicate cement sealers. This chemical matrix for such sealers was developed on the basis of the success of bioactive mineral trioxide aggregate-type (tricalcium silicate cement) materials for enhanced sealing and bioactivity. METHODS: The authors searched the internet and databases using Medical Subject Heading terms and then conducted a narrative review of those articles involving the tricalcium silicate cement endodontic sealers. RESULTS: Ninety-four articles were identified that discussed tricalcium silicate cement sealers. Tricalcium silicate cement sealers are partially antimicrobial and have bioactivity, which may presage improved biological sealing of the root canal system. Most other properties of tricalcium silicate cement sealers are comparable with traditional root canal sealers. CONCLUSIONS: Within the limitations of this review, tricalcium silicate cement endodontic sealers met many of the criteria for ideal properties, such as placement, antimicrobial properties, and bioactivity, but limitations were noted in solubility, dimensional stability (shrinkage and expansion), and retrievability. PRACTICAL IMPLICATIONS: Tricalcium silicate-based cements have been commercialized as bioactive, bioceramic endodontic sealers. Warm, cold, and single-cone obturation techniques are usable, depending on the commercial product. Some sealers can cause discoloration and are not easily retrievable, particularly when used to completely obturate a canal.

Emerging antiresorptive medications and their potential implications for dental surgeries.

BACKGROUND: The aim of this review was to discuss the current and newly emerging antiresorptive medications and their potential implications for dental surgeries. TYPES OF STUDIES REVIEWED: The authors searched PubMed (MEDLINE), Cochrane, Embase, and other electronic databases for articles related to osteonecrosis of the jaw and medication-related osteonecrosis of the jaw (MRONJ). In addition, the authors hand searched the bibliographies of all relevant articles, the gray literature, textbooks, and guidelines in association position statements. RESULTS: The following information for MRONJ risk should be evaluated before any invasive dental procedure: metastatic carcinoma has a higher risk than osteoporosis; parenterally administered bisphosphonates and denosumab have a higher risk than orally administered bisphosphonates or antiangiogenic agents; dose and duration of medication received; adjunctive medications or combination of antiresorptive agents also may increase the risk of MRONJ; additive factors and comorbidities such as diabetes, autoimmune disease, immunosuppression, or any condition that might affect healing negatively would result in potentially higher risk of developing MRONJ; angiogenic inhibitors as part of a cancer treatment regimen, with or without antiresorptive medication, are considered high risk. PRACTICAL IMPLICATIONS: Patients who received antiresorptive therapy for malignancy were at higher risk of developing MRONJ than those who received the therapy for osteoporosis, regardless of the route of administration and type of drug. Antiangiogenic agents, bevacizumab, aflibercept, and tyrosine kinase inhibitors such as sunitinib were implicated most commonly in the development of MRONJ. Patients who are taking multiple doses of angiogenic inhibitors should be monitored closely for early diagnosis of possible MRONJ.

Current Concepts of Dentinal Hypersensitivity.

INTRODUCTION: Although many clinical studies have reported on the prevalence of dental pain, far fewer studies have focused on the mechanisms of dental pain. This is an important gap because increased understanding of dental pain mechanisms may lead to improved diagnostic tests or therapeutic interventions. The aim of this study was to comprehensively review the literature on the mechanisms of dentinal sensitivity. METHODS: PubMed and Ovid were searched for articles that addressed dentinal pain and or pulpal sensitivity. Because of the breadth of research ranging from cellular/molecular studies to clinical trials, a narrative review on the mechanisms of dentinal sensitivity was constructed based on the literature. RESULTS: Five various mechanisms for dentinal sensitivity have been proposed: (1) the classic hydrodynamic theory, (2) direct innervation of dentinal tubules, (3) neuroplasticity and sensitization of nociceptors, (4) odontoblasts serving as sensory receptors, and (5) algoneurons. CONCLUSIONS: These theories are not mutually exclusive, and it is possible that several of them contribute to dentinal sensitivity. Moreover, pulpal responses to tissue injury may alter the relative contribution of these mechanisms. For example, pulpal inflammation may lead to neuronal sprouting and peripheral sensitization. Knowledge of these mechanisms may prompt the development of therapeutic drugs that aim to disrupt these mechanisms, leading to more effective treatments for pulpal pain.

Perioperative Antiplatelet and Anticoagulant Management with Endodontic Microsurgical Techniques.

INTRODUCTION: The purpose of this study was to review evidence-based recommendations for the safe perioperative management of patients undergoing endodontic microsurgery who are currently taking antiplatelet or anticoagulant medications. Using the PICO (Population, Intervention, Comparison, Outcome) format, the following scientific question was asked: In patients taking anticoagulant or antiplatelet agents, what is the available evidence in the management of endodontic microsurgery? METHODS: MEDLINE, Scopus, Cochrane Library, and ClinicalTrials.gov databases were searched to identify current recommendations regarding the management of antiplatelet and anticoagulant medications in the context of outpatient dental surgical procedures. Additionally, the authors hand searched the bibliographies of all relevant articles, the gray literature, and textbooks. Because of the lack of clinical studies and evidence on this subject, articles and guidelines from other organizations and association position statements were included. RESULTS: Because any minor surgery can become a major surgery, the treating doctor needs to best assess the risk of bleeding, especially if the surgery is anticipated to take longer than 45 minutes. Every patient should be stratified on a case-by-case basis. Consultation with the patient's physician is highly recommended. CONCLUSIONS: In order to maximize the effects of these medications (to prevent thrombosis) while minimizing the potential risks (procedural hemorrhage), clinicians should be aware of the best available evidence when considering continuation or discontinuation of antiplatelet and anticoagulant agents perioperatively for endodontic microsurgery. Ideally, a joint effort from an expert panel for microsurgery would be warranted.

The impact of sealer extrusion on endodontic outcome: A systematic review with meta-analysis.

The purpose of this systematic review was to qualify and quantify the evidence regarding the effect of extruded sealers on endodontic treatment outcomes. Two reviewers independently conducted a comprehensive literature search. The EMBASE, MEDLINE, Cochrane, PubMed databases, bibliographies, grey literature of all relevant articles and textbooks were searched. Six articles met the inclusion criteria with a moderate risk of bias and were analysed for qualitative and quantitative synthesis. There was moderate-certainty evidence that sealer extrusion can contribute to non-healing outcomes, 95% confidence interval, risk ratio 1.32 (1.12-1.54) and P < 0.05. This indicates that the current authors are somewhat confident the true effect is likely to be close to the estimate of the effect. Sealer extrusion had a 32% higher risk of contributing to a non-healing outcome than no extrusion. However, well-conducted research would need to be conducted to confirm this causality claim.

Declassifying Mobility Classification.

INTRODUCTION: Tooth mobility is often discussed among dental health care providers according to a numerical scale (ie, 1, 2, or 3) without a clear understanding of the definition of each category. Thus, a comprehensive review to examine and discuss the various classifications is needed. The aim of this comprehensive review was to discuss the main clinical classifications of tooth mobility. METHODS: The authors conducted electronic searches in MEDLINE, Scopus, and PubMed. Additionally, the authors manually searched the textbooks, gray literature, and bibliographies of all relevant articles. RESULTS: The most commonly referenced clinical index for mobility was the Miller index; yet, many other mobility classifications exist as well as modifications of those indexes. The literature has been very inconsistent and at times inaccurate when classifying mobility; using various stages of mobility using grades, classes, and scores interchangeably and not defining the meaning of the actual numerical scores/terminologies are common problems. CONCLUSIONS: In order to avoid ambiguity and provide clarity regarding the impact of degrees of mobility when used clinically, this review comprehensively discusses different classifications and definitions of tooth mobility with attention to the importance of using them consistently and accurately. There is a need to standardize 1 classification for mobility.

Assessment of the accuracy of two gutta-percha gauges used to alter gutta-percha tip diameter.

This study sought to compare the accuracy of two gauges used to alter gutta-percha (GP) cone tips. Randomly selected size 20 cones (with tapers of 0.02, 0.06, 0.10, or 0.12) were trimmed to size 50 (N= 10/taper/gauge) for an overall sample of 80 cones. Accuracy of the altered cone tips was determined by calculating the difference (in %) between the altered tip diameter and the expected tip diameter (0.50 mm). A two-factor ANOVA revealed significant differences (p < or = 0.05) in altered tip accuracy as a result of GP gauge and cone taper. The results suggest that the SybronEndo gauge performs accurately regardless of the cone taper, while the Maillefer gauge was accurate only when used to alter cones with a 0.02 taper.

Use of cone-beam computed tomography to identify root canal systems in vitro.

This study investigated the use of cone-beam computed tomography (CBCT) as a diagnostic tool for identifying root canal systems (RCSs) when compared with images obtained by using charged coupled device (CCD) and photostimulable phosphor plate (PSP) digital radiography in vitro. Seventy-two extracted teeth were exposed with CCD, PSP, and CBCT radiography. Specimens included 24 maxillary molars, mandibular premolars, and mandibular incisors each. Tooth-type selections were based on the greater possibility of multiple RCSs. Three board-certified endodontists evaluated CCD and PSP images to determine the number of RCSs. CBCT images were used to establish "ground truth" for the comparisons and were evaluated by a board-certified oral and maxillofacial radiologist who determined the number of RCSs. Descriptive statistical analysis revealed that the endodontists consistently agreed among themselves. When compared with CBCT evaluation, the endodontists, on average, failed to identify 1 or more RCSs in 41% of the teeth with CCD and 40% of the time with PSP. CBCT evaluations identified an average of 3.58 RCSs per maxillary molar, 1.21 per mandibular premolar, and 1.5 per mandibular incisor. Evaluation of CCD images demonstrated an average number of 1.0 RCSs per mandibular incisor, 1.0 per mandibular first premolar, and 3.1 per maxillary molar. Evaluation of PSP images demonstrated an average number of 1.3 RCSs per mandibular incisor, 1.1 per mandibular first premolar, and 3.0 per maxillary molar. In summary, endodontist evaluators with either CCD or PSP methods failed to identify at least 1 RCS in approximately 4 of 10 teeth, which can result in a less optimal healing outcome if a missed RCS is left uninstrumented and unobturated.

Size of Master Apical File and Optimal Irrigation of the Apical Zone: A Systematic Review.

Introduction: To determine what would be the minimal apical diameter for optimal chemomechanical preparation in the root canal system in terms of debridement and/or irrigation delivery, in patients undergoing nonsurgical root canal treatment. Methods and Materials: Randomized controlled clinical trials, cohorts, cross-over studies from peer-reviewed journals published in English from January 1950 to June 2018 which reported outcome in terms of healing, microbial reduction and/or effectiveness of irrigation delivery to the apical third of the root canal system. Two reviewers conducted a comprehensive literature search. There were no disagreements between the two reviewers. The articles that met the inclusion criteria went through a predefined review process. Results: Due to the variety of methodologies and different techniques used to measure outcome for master apical file enlargement, it was not possible to standardize the research data and to perform meta-analysis. Twelve clinical articles were identified that met the inclusion criteria. Conclusions: The overall level of evidence on this topic was moderate (fair). From this systematic review, the majority of the studies collected and referred to recommend sizes higher than #30 as the minimal size in order to adequately prepare the apical region of the root canals. Only 2 out of 12 studies suggested the size #25 as acceptable. From this systematic review it may be concluded that a larger MAF preparation above size 30 aids chemomechanical action.

Cone-beam Computed Tomography Compared with Intraoral Radiographic Lesions in Endodontic Outcome Studies: A Systematic Review.

INTRODUCTION: The purpose of this systematic review was to compare and quantify endodontic outcome using cone-beam computed tomographic (CBCT) imaging with intraoral periapical radiography. METHODS: Two reviewers independently conducted a comprehensive literature search. The MEDLINE, Embase, Cochrane, and PubMed databases were searched. Additionally, bibliographies, gray literature of all relevant articles, and textbooks were manually searched. There was no disagreement between the 2 reviewers. RESULTS: Six articles met the inclusion criteria with low to moderate risk of bias (good/fair quality). The certainty of evidence was moderate, indicating that the authors are moderately confident that the true effect lies close to that of the estimate of the effect as determined by Grading of Recommendations Assessment Development and Evaluation criteria. The odds ratio of CBCT imaging versus traditional imaging to detect a periapical lesion was 2.04 (95% confidence interval, 1.52-2.73). CONCLUSIONS: Although intraoral radiographs are the imaging modality of choice, when 2-dimensional intraoral radiography is inconclusive, CBCT imaging was reported in this investigation to have twice the odds of detecting a periapical lesion than traditional periapical radiography in endodontic outcome studies.

The Impact of Endodontic Infections on the Pathogenesis of Cardiovascular Disease(s): A Systematic Review with Meta-analysis Using GRADE.

INTRODUCTION: The purpose of this systematic review was to determine whether endodontic infections had an impact on the pathogenesis of systemic disease. METHODS: Two reviewers independently conducted a comprehensive literature search. The MEDLINE, Embase, Cochrane, and PubMed databases were searched. In addition, the bibliographies, gray literature of all relevant articles, and textbooks were manually searched. There was no disagreement between the 2 reviewers. RESULTS: Four articles met the inclusion criteria with a high risk of bias. Three articles were analyzed for quantitative synthesis. All these articles were regarding cardiovascular disease (CVD). There was low-certainty evidence that a lesion of endodontic origin can contribute to systemic disease, 95% confidence interval, risk ratio 1.2 (0.79-1.83). Owing to high heterogeneity among the studies, sub-group analysis was undertaken. The results reported more consistent outcome with risk ratio 0.95 (0.75-1.21) and low certainty. Therefore, the authors have limited confidence in the effect estimate, which indicates that the true effect may be substantially different from the estimate of the effect. CONCLUSIONS: Whether the presence of a lesion of endodontic origin may or may not have some impact on cardiovascular disease, the level of evidence is low, and our confidence in the assessment is low. This systematic review raised questions in the designs and analysis of the data, and further well-conducted longitudinal research would be required to make this causality claim.

Assessment of a thermoplasticized gutta-percha delivery system to effectively obturate canals with varying preparation dimensions.

The purpose of this study was to measure the ability of a thermoplasticized-injectable (TPI) gutta-percha (GP) delivery system to fill a prepared root canal to working length and replicate intracanal defects (coronal, middle, apical) as a function of root canal preparations with varying lateral dimensions. Three split-tooth models with 0.06 taper and different apical gauge preparations, 0.30 mm (group A), 0.40 mm (group B), and 0.50 mm (group C), were used. Obturations were evaluated using an ordinal scale (0-4) based on how much each intracanal defect was replicated. Coronal and middle defects were completely replicated 100% of the time, regardless of the preparation. However, there was a significant difference (p

Apical Periodontitis, a Predictor Variable for Preeclampsia: A Case-control Study.

INTRODUCTION: Preeclampsia (PE) is characterized by hypertension and proteinuria after the 20th week of gestation. There is an association between systemic inflammation and adverse pregnancy outcomes such as PE. Therefore, for the first time, the present study aimed to investigate the possible association between maternal apical periodontitis (AP) and PE. METHODS: In this case-control study, 50 mothers who were diagnosed with PE during pregnancy were included in the experimental group. The control group consisted of 50 matched mothers with a normal course of pregnancy. The endodontic and periodontal status of all participants was reviewed using the digital panoramic radiographs that were available before pregnancy. The number of remaining teeth and the presence of AP in all teeth and endodontically treated teeth were recorded using the periapical index. Binary logistic regression was used to determine the possible association between AP and PE (α = 0.05). RESULTS: AP in at least 1 tooth was found in 27 of the mothers who developed PE (54%) and in 16 of the control patients (32%) (odds ratio [OR] = 2.4, P < .05). Adjusted for the maternal periodontitis, number of teeth, and endodontic treatment, maternal AP was significantly associated with the occurrence of PE (P < .05; OR = 2.23; 95% confidence interval, 95% = 1.92-6.88). CONCLUSIONS: AP was significantly more prevalent in the experimental group. For the first time, this study has provided evidence that maternal AP may be a strong independent predictor of PE. Considering the high occurrence of PE, particularly in developing countries, it could be suggested that the risk of PE may be reduced through comprehensive dental examinations for detecting and treating any source of inflammation, including AP, before pregnancy.

Association between Systemic Diseases and Endodontic Outcome: A Systematic Review.

INTRODUCTION: To date, the relationships between systemic diseases and endodontic treatment outcomes remain poorly studied. Thus, the purpose of this systematic review was to evaluate the relationship between host-modifying factors and their association with endodontic outcomes. METHODS: Two reviewers independently conducted a comprehensive literature search. The MEDLINE, Embase, Cochrane, and PubMed databases were searched. In addition, the bibliographies and gray literature of all relevant articles and textbooks were manually searched. There was no disagreement between the 2 reviewers. RESULTS: Sixteen articles met the inclusion criteria with moderate to high risk of bias. There was no article with low risk of bias. Available scientific evidence remains inconclusive as to whether diabetes and/or cardiovascular disease(s) may be associated with endodontic outcomes. Human immunodeficiency virus and oral bisphosphonate did not appear to be associated with endodontic outcomes. CONCLUSIONS: Although additional well-designed longitudinal clinical studies are needed, the results of this systematic review suggest that some systemic diseases may be correlated with endodontic outcomes.

The Influence of Periodontal Status on Endodontically Treated Teeth: 9-year Survival Analysis.

INTRODUCTION: The aim of this study was to investigate the effect of periodontal status at the time of nonsurgical root canal treatment (NSRCT) on the survival rate of endodontically treated teeth (ETT). METHODS: In this retrospective investigation, molars that received NSRCT in an advanced specialty education program in endodontics from 2009 through 2017 were initially recruited. After the application of inclusion and exclusion criteria, 315 teeth were included in the study. Inclusion criteria were ETT with an acceptable quality of NSRCT; ETT that received an adequate crown within 3 months after NSRCT; and ETT with complete periodontal charting before NSRCT including pocket depths, clinical attachment loss, and bone loss. The periodontal status of all included teeth was assessed based on American Academy of Periodontology guidelines. All included ETT were divided into 3 groups as follows: healthy group, mild periodontitis, and moderate periodontitis. The survival rate of ETT was analyzed using univariate Kaplan-Meier and log-rank tests for differences between groups (P < .05). A Cox regression model was used to assess the effect of independent variables on the survival rate. RESULTS: Teeth that were diagnosed with mild periodontitis were almost 2 times more likely to be extracted compared with ETT diagnosed with normal periodontium at the time of NSRCT (odds ratio [OR] = 1.9, P < .05). This increased risk of tooth loss was 3.1 (OR = 3.1, P < .05) for ETT diagnosed with moderate periodontitis. Smokers were twice as likely to have tooth loss compared with nonsmokers (OR = 2.2, P < .05). CONCLUSIONS: Patients' periodontal health, being 1 of the prognostic determinants of the outcome of NSRCT, requires attention before and subsequent to NSRCT. This may improve the survival of ETT and help patients maintain their natural dentition.

Association of End-stage Renal Disease with Radiographically and Clinically Diagnosed Apical Periodontitis: A Hospital-based Study.

INTRODUCTION: The present study aimed to evaluate the prevalence of apical periodontitis (AP) and endodontic treatment in patients with end-stage renal disease (ESRD) as compared with patients with no history of ESRD. METHODS: In this cross-sectional study, 40 patients diagnosed with nondiabetic ESRD were included. The control group consisted of 40 age-matched and sex-matched healthy individuals. Digital panoramic radiographs were exposed on patients in both the experimental and control groups. The number of remaining teeth and the prevalence of nonsurgical and/or surgical root canal treatment were evaluated. Also, the presence of AP in all teeth and endodontically treated teeth (ETT) was recorded using the periapical index. Logistic regression was used to determine the possible association between ESRD and AP. RESULTS: AP in at least 1 tooth was found in 29 of the patients with ESRD (73%) and in 16 of the control patients (40%) (odds ratio [OR] = 3.9, P < .05). In 21 (52%) patients with ESRD in the experimental group, at least 1 ETT was diagnosed with AP. In the control group, 11 (28%) individuals had AP affecting at least 1 of the ETT (OR = 2.9, P < .05). Adjusted for the number of teeth and endodontic treatment, ESRD was significantly associated with the presence of AP (P < .05; OR = 2.6; 95% confidence interval, 1.43-4.8). Also, the number of teeth with AP was significantly associated with the urea serum level in the experimental group (P < .05, ß coefficient = 4.35). CONCLUSION: AP was significantly more prevalent in the experimental group. This may suggest that ESRD could possibly alter the pathogenesis of AP. However, these findings do not confirm the presence of any cause-and-effect relationship between these conditions. Also, considering the modifying effect of AP on urea serum level, the treatment of AP could be incorporated in the treatment planning of patients with ESRD.

The Association between the Anatomic Landmarks of the Pulp Chamber Floor and the Prevalence of Middle Mesial Canals in Mandibular First Molars: An In Vivo Analysis.

INTRODUCTION: The present study aimed to determine the incidence and anatomic variation of the middle mesial (MM) canal in mandibular permanent first molars using cone-beam computed tomographic imaging and to evaluate the association between the presence of MM canals and anatomic landmarks of the pulp chamber floor in the mesial root. METHODS: In this in vivo cross-sectional study, 210 CBCT scans of mandibular fist molars from 210 patients were included. CBCT scans were evaluated in 3 sections, and the following data were collected for further analysis: identification of the MM canal, the distance between the mesiobuccal (MB) and mesiolingual (ML) orifices, the presence of any isthmus between the MB and ML orifices, and the MB and ML root canal system (RCS) configurations. Binary logistic regression was performed to assess the effect of pulp floor anatomic characteristics as an independent variable on the outcome variable (the presence of an MM canal). RESULTS: The overall prevalence of the identification of an MM canal regardless of age was 14.7%. Mandibular first molars with an isthmus between the MB and ML RCS configurations were almost 5 times more likely to show an MM canal (P < .05, odds ratio [OR] = 4.9). The MB-ML intraorifice distance was inversely associated with the presence of an MM canal (P < .05, OR = 0.73). Patients less than 42 years old were 4 times more likely to have an MM canal in their CBCT scans compared with patients older than 42 years old (P < .05, OR = 3.9). CONCLUSIONS: The suggested anatomic landmarks of the pulp chamber floor could act as a reliable predictive factor for the presence of an MM canal. This knowledge of anatomic clues may serve to better direct endodontists in locating an MM canal, which could prevent excessive removal of tooth structures.

The Effect of the Dental Operating Microscope on the Outcome of Nonsurgical Root Canal Treatment: A Retrospective Case-control Study.

INTRODUCTION: The aim of the current investigation was to assess the effect of the use of a dental operating microscope on the outcome of nonsurgical root canal treatment (NS RCT) while treating the mesiobuccal (MB) root of the maxillary first molar. METHODS: This retrospective investigation included endodontically treated maxillary first molars (ETMs) with apparent adequate previous NS RCT and restorations referred for endodontic retreatment at the endodontic graduate clinic. Inclusion criteria were ETMs that were diagnosed with irreversible pulpitis and normal periapical tissues before the initial NS RCT and ETMs that presented with a minimum of 1 identifiable periapical lesion (PAR) at 1 of the roots at the time of retreatment. One hundred ninety-five ETMs were included and divided into 2 groups: (1) the initial NS RCT had been performed using a microscope (n = 83) and (2) NS RCT had been performed without the use of a microscope (n = 112). Data extracted were whether the second MB (MB2) canal was located initially and the presence of an MB PAR at the time of retreatment. Data were statistically analyzed using binary logistic regression (α = 0.05). RESULTS: The MB root was 3 times more likely to present with a PAR at the time of retreatment if the initial NS RCT was performed without the use of a microscope (P < .05, odds ratio = 3.1). There was a significant association between a missed MB2 canal and an MB PAR in the group in which the initial NS RCT was performed without the use of a microscope (P < .05, odds ratio = 5.1). However, in cases in which the initial NS RCT was performed using a microscope, a missed MB2 canal was not associated with the presence of an MB PAR. CONCLUSIONS: With proper education, dentists can gain further insight into recognizing limitations in treating cases that require advanced training and advanced optics such as a microscope. Based on this strategy, it would appear that the outcome of NS RCT can be improved.

Variability of the diameter and taper of size #30, 0.04 gutta-percha cones.

The purpose of this investigation was to examine variability of gutta-percha (GP) cone tip diameter (D(0)) and taper among five different brands of #30, 0.04 GP cones (n = 15/brand). Mean percent D(0) difference from the manufacturer's reported (nominal) diameter of Maillefer (-15.42 +/- 7.16%) and Lexicon (-12.76 +/- 4.98%) were significantly different (p < or = 0.05) from Maxima (3.18 +/- 7.06%), Diadent (3.62 +/- 11.37%), and K(3) (7.27 +/- 7.84%), which were not significantly different from each other but exhibited diameters larger than the nominal diameter as indicated by positive values. Mean taper percent difference of Maxima (-3.00 +/- 3.80%) was significantly different (p < or = 0.05) from Lexicon (3.67 +/- 3.64%) and Maillefer (6.67 +/- 3.49%), with comparisons to Diadent (-0.17 +/- 6.37%) and K(3) (1.50 +/- 6.93%) not significantly different (p > 0.05) from each other or any other brand. Based on the evidence, there is significant variability between GP cone brands for both diameter and taper, with Maxima and Diadent, respectively, exhibiting the smallest mean difference from manufacturer's nominal tip diameter and taper. However, the high standard deviation values associated with most of the diameter and taper differences from nominal values also suggest high variability within individual brands.

Variability of the diameter and taper of size #30, 0.04 nickel-titanium rotary files.

This investigation examined the variability of tip diameter (D0) and taper measurements among four different brands of #30, 0.04 nickel-titanium (NiTi) rotary files (n=15/brand). With all brands, the mean percent D0 difference from the manufacturer's reported (nominal) diameter (Profile GT, 1.73+/-2.03%; Endo Sequence, 3.38+/-3.91%; K3, 4.56+/-2.36%; Profile, 6.13+/-4.07%) indicated that files tended to be larger than the nominal diameter. A 1-factor ANOVA and Tukey's post hoc test revealed a statistically significant difference (p0.05) of brand on the mean percent difference of the measured taper compared to the nominal taper with the majority of measurements at either 0.039 or 0.040 taper.