Outcome of Endodontic Treatment: The Most Cited Publications.

INTRODUCTION: Bibliographic analysis using quantitative measurements such as citation number and citation density is a common method used to evaluate the impact of previously published studies on current research. Several bibliographic endodontic studies ranking publications based on their number of citations have been published. However, to date, a focus on the most cited articles related to the outcome of endodontic treatment is lacking. The purpose of this study was to identify the most cited publications and their citation density as related to the outcome of nonsurgical root canal treatment (NSRCT), nonsurgical root canal retreatment (NSRCR), and root canal surgery (RCS). METHODS: A search of all citations regarding the outcome of NSRCT, NSRCR, and RCS was performed using the Web of Science platform. The search included key words covering all relevant categories. Only publications in the English language published between May 1960 and July 2021 were included. The publications were divided into the following groups: NSRCT, NSRCR, and RCS. Each group was further subdivided into experimentation studies and review studies. The publications were analyzed and sorted in descending order according to the number of citations that each publication has received. Only publications with 100 citations or more were included. Citation density was also assessed. RESULTS: The total number of NSRCT citations found was 257; 221 (86%) were experimentation studies, and 36 (14%) were review studies. Of the 221 NSRCT experimentation studies, 41 (18.55%) had 100 citations or more. Of the 36 NSRCT review studies, 9 (25%) had 100 citations or more. The total number of NSRCR citations found was 61; 51 (83.6%) were experimentation studies, and 10 (16.4%) were review studies. Of the 51 NSRCR experimentation studies, 5 (9.8%) had 100 citations or more. Of the 10 NSRCR review studies, 2 (20%) had 100 citations or more. The total number of RCS citations found was 119; 90 (75.6%) were experimentation studies, and 29 (24.4%) were review studies. Of the 90 RCS experimentation studies, 11 (12.2%) had 100 citations or more. Of the 29 RCS review studies, 2 (6.9%) had 100 citations or more. In total, 70 publications on the outcome of endodontic treatment had 100 or more citations. Fifty publications (71.4%) pertained to the NSRCT groups, 7 publications (10%) to the NSRCR groups, and 13 publications (18.6%) to the RCS groups. CONCLUSIONS: Bibliographic analysis is a beneficial aid for assessing the impact of publications studying the outcome of endodontic treatment on the field of endodontics.

Effect of master apical file size and taper on irrigation and cleaning of the apical third of curved canals.

OBJECTIVE: Canal preparation generates a substantial amount of debris and smear layer (SL). The size and taper of the Master Apical File (MAF) affects on penetration of irrigants and subsequently canal cleaning efficacy. The aim of this study was to evaluate the effect of MAF size and taper on penetration of irrigants to the apical third of curved mesiobuccal (MB) canals of mandibular first molars. MATERIALS AND METHODS: Eighty-nine human mandibular first molars were divided into one control group (n=5) without rotary instrumentation and 6 experimental groups (n=14 each) that were prepared with the following RaCe rotary files as MAF: 25.04 (group1), 25.06 (group 2), 30.04 (group 3), 30.06 (group 4), 35.04 (group 5) and 35.06 (group 6). All the experimental groups were rinsed with 2 ml of 17 % EDTA followed by 2 ml of 5.25% NaOCl. Debridement of the MB canals was evaluated using scanning electron microscope (SEM). The data were statistically analyzed using Kruskal-Wallis and Mann-Whitney U tests (P<0.05). RESULTS: Group 6 (MAF=35.06) showed 100% acceptable debridement. This rate was 92.9% for MAF=35.04. In group 4 (MAF=30.06) smear layer (SL) was removed in the three-forth of the samples and debris was removed in 92.9% of them. Acceptable debridement was not achieved in most samples of groups 1 and 2 (25.04 and 25.06, respectively) and the mentioned two groups had statistically significant difference in this respect with the other groups (P<0.05). CONCLUSION: Based on this study, 30.06 may be considered as the minimum MAF size for acceptable debridement.

In Vitro Comparison of Gutta-Percha Removal with H-File and ProTaper with or without Chloroform.

INTRODUCTION: Removal of root filling materials is one of the key steps in success of root canal retreatment. The purpose of this study was to evaluate the efficacy of H-File and ProTaper with or without chloroform in the removal of gutta-percha during retreatment of mandibular premolars. MATERIALS AND METHODS: Sixty mandibular premolars with one canal, and curvatures less than 30 degrees were used in this experimental study. They were instrumented with K-files and laterally obturated with condensed gutta-percha using AH26 as the sealer and were stored in 100% humidity at 37°C for 2 weeks. The teeth were randomly divided into four groups of 15 teeth each. Removal of gutta-percha was performed with H-File and ProTaper. All techniques were used with or without chloroform. The teeth were split longitudinally and the area of remaining gutta-percha/sealer on the root canal wall was explored under stereomicroscope. Retreatment time duration was also recorded for each sample. Data were analyzed statistically by Two-way ANOVA, t-test and Tukey's. RESULTS: In all groups, no significant difference was found in remaining gutta-percha and sealer with or without using chloroform, but chloroform shortened the time of retreatment. ProTaper left significantly less remaining filling materials than H-File (P<0.05). Retreatment time was significantly different between the studied groups (P<0.001). CONCLUSION: ProTaper Ni-Ti instruments proved to be more efficient and time-saving devices for removal of gutta-percha compared to H-File in canals with no or slight curvature.

Efficacy of Two Rotary NiTi Instruments in Removal of Resilon/Epiphany Obturants.

INTRODUCTION: The success of endodontic retreatment is related to the complete removal of the obturation material from the root canal system. The aim of this study was to evaluate the efficacy of Mtwo R and ProTaper retreatment files in removing the Resilon/Epiphany system with or without chloroform during retreatment. MATERIALS AND METHODS: Sixty distal roots of first mandibular molars were prepared and laterally condensed with Resilon/Epiphany, then divided into four groups (15 each for retreatment): 1) Mtwo R/solvent; 2) Mtwo R; 3) ProTaper D/solvent; and 4) ProTaper D. The cleanliness of the canal walls was evaluated using radiography; a stereomicroscope and SEM. Data were subjected to ANOVA and Student's t-test. RESULTS: Neither rotary system performed better than the other when considering the whole root canal, with or without solvent. In the apical portion, ProTaper/solvent showed the best result (P<0.05). CONCLUSION: In Resilon/Epiphany retreatment cases, ProTaper/solvent was better in the apical portion; however when considering the whole canal, Mtwo R and the ProTaper D series had the same performance.

An in vitro study of mesiobuccal root thickness of maxillary first molars.

INTRODUCTION: Understanding the internal anatomy of root canal system can significantly influence outcomes of root canal treatment. The aim of this in vitro study was to measure the thickness of mesiobuccal root at different levels in maxillary first molars. MATERIALS AND METHODS: In this cross-sectional study, forty extracted human maxillary first molars were radiographed; accordingly, the mesial and distal root thicknesses of mesiobuccal (MB) roots were measured at four parallel horizontal levels. The samples were sectioned at the measured levels and then sections were scanned and saved in the computer. Buccal (B), Palatal (P), Mesial (M) and Distal (D) aspects of root thicknesses in single-canalled roots were measured. In two-canalled mesiobuccal roots, Distobuccal (DB) and Distopalatal (DP) aspects were evaluated alongside other measurements. Average radicular thickness in each aspect and each level was compared using ANOVA and t-test. RESULTS: A total of 25 had two canals and 15 had one canal in MB root. In single-canalled roots M and D aspects were the thinnest whereas in two-canalled samples, the thicknesses of DP and DB aspects were significantly less than others (P<0.001). The B and P had the greatest thicknesses in all the samples. CONCLUSION: The results showed that special attention should be paid to "danger zone" areas of mesiobuccal maxillary first molar roots in order to avoid technical mishaps.

Remoção de pasta de hidróxido de cálcio intracanal com dois sistemas rotativos: RaCe e Mtwo

Introdução: o objetivo desse estudo foi comparar a eficácia de dois sistemas rotativos na remoção de hidróxido de cálcio das paredes do canal radicular. Métodos: um total de 44 canais radiculares distovestibulares de molares maxilares humanos com curvaturas entre 15 e 25° foi dividido aleatoriamente em dois grupos de 20 canais cada e dois grupos controle. Os corpos de provado Grupo A foram instrumentados com sistema rotativo RaCe e os do Grupo B com sistema rotativo Mtwo até#35 (4%). Os canais foram lavados com 5ml de NaOCla 2,5% entre cada instrumento e uma lima K #10 foi utilizada na desobstrução (patência) durante a limagem. A pasta de hidróxido de cálcio foi aplicada nos canais e,após a incubação, foi removida dos canais com o Master Apical Rotary (MAR) e NaOCl em todos os grupos.As raízes foram divididas longitudinalmente e os remanescentes foram avaliados em estereomicroscópio em três níveis distintos, usando um sistema de pontuação.Os dados foram analisados estatisticamente com o teste ANOVA. Resultados: não foi encontrada diferença significativa em nenhum dos grupos com nenhum dos dois sistemas — RaCe e Mtwo (p>0,05). A soma dos escores aceitáveis foi de 53,6% para o RaCe e 51,3% para o Mtwo. Conclusão: todos os canais apresentaram remanescentes de hidróxido de cálcio. Embora não tenha havido nenhuma diferença significativa entre os grupos,o sistema Mtwo deixou uma impressão clínica de limpeza ligeiramente melhor em termos de remoção do hidróxido de cálcio.

Additive effect of a diode laser on the antibacterial activity of 2.5% NaOCl, 2% CHX and MTAD against Enterococcus faecalis contaminating root canals: an in vitro study.

This in vitro study was performed to evaluate the effect of a diode laser and common disinfectants used in combination on mono-infected dental canals. One hundred and six single-rooted human premolars were prepared and contaminated with Enterococcus faecalis. After two weeks of incubation, samples were divided into two experimental groups (n = 48) and two control groups (n = 5). In the first group, the teeth were rinsed for 5 min with either sterile saline, 2.5% NaOCl, or MTAD, or for 1 min with 2% chlorhexidine gluconate (CHX). In the other group, samples were additionally irradiated with a 810-nm diode laser at 2 W output for 5 × 5 s. Intracanal bacterial sampling was done, and the samples were plated to determine the CFU count. In the first group, 2.5% NaOCl was as effective as 2% CHX and significantly more effective than MTAD (P < 0.008). In the second group, either MTAD, 2% CHX or 2.5% NaOCl in combination with laser treatment had a similar effect. Absence of growth was seen only for MTAD plus laser treatment. Complete elimination of E. faecalis was seen only for the combination of MTAD with diode laser irradiation. Combination therapy with MTAD irrigation and diode laser irradiation, within the parameters used in this study, can be recommended as an effective treatment option for complete elimination of E. faecalis from the root canal system.

Effect of ultrasonication with EDTA or MTAD on smear layer, debris and erosion scores.

The purpose of this study was to compare the effects of ultrasonication with ethylenediaminetetraacetic acid (EDTA) and a mixture of tetracycline isomer, an acid, and a detergent (MTAD) as final canal irrigants on the smear layer, debris and erosion scores. Fifty-eight extracted single-rooted human teeth were instrumented with ProTaper rotary files up to size F3. According to the final irrigation regimen, the samples were distributed into the following groups: EDTA, MTAD, EDTA ultrasonicated for 1 min, and MTAD ultrasonicated for 1 min. The smear layer, debris and erosion scores were recorded at the apical, middle, and coronal third of each canal using a scanning electron microscope. Data were subjected to statistical evaluation using the Kruskal-Wallis and Mann-Whitney tests (P < 0.05). There were no significant differences in smear layer or debris removal between the experimental groups. EDTA caused significantly more erosion at the middle level than MTAD. Also EDTA resulted in more erosion at the coronal level than MTAD when subjected to ultrasonication. Ultrasonic activation of EDTA significantly increased its erosive effects at the middle and coronal levels. Based on the present findings, MTAD appears to cause less dentinal erosion while allowing proper removal of the smear layer and debris.

Efficacy of two rotary systems in removing gutta-percha and sealer from the root canal walls.

INTRODUCTION: The aim of this in vitro study was to compare the efficacy of two retreatment rotary systems in removal of gutta-percha (GP) and sealer from the root canal walls with and without use of solvent. MATERIALS AND METHODS: Sixty single-canalled distal roots of mandibular molars were prepared and root filled with gutta-percha and AH26. Each canal was randomly allocated to receive one of the retreatment techniques, Mtwo R or ProTaper. The groups were further divided into two subgroups: with or without the use of solvent. The cleanliness of canal walls was determined by stereomicroscope and scanning electron microscopy. RESULTS: The results showed that Mtwo R without the use of solvent was more efficient in material removal compared to ProTaper D (P<0.05). Most remnants were found in the apical third of the canals (P<0.05). CONCLUSION: Mtwo R seems to be an efficient rotary system for endodontic retreatment of root canal with GP.

Comparative study of the sealing ability of the lateral condensation technique and the BeeFill system after canal preparation by the Mtwo NiTi rotary system.

The purpose of this in vitro study was to compare the sealing ability of the lateral condensation technique and the BeeFill system after canal preparation by the Mtwo rotary system. Forty extracted single-rooted teeth were prepared by using the Mtwo rotary system. The teeth were then divided into 2 experimental groups (n = 15 each) and 2 control groups (n = 5 each). The specimens in groups 1 and 2 were obturated using the lateral condensation technique and the BeeFill system, respectively. The teeth in the negative control group were also obturated with the lateral condensation technique, and the specimens in the positive control group were not root-filled. The specimens were then immersed in an aqueous solution of 2% China ink for 1 week, after which the roots were cleared and the linear extent of dye penetration was measured with a stereomicroscope by 2 endodontists. The data collected were then analyzed by using the 1-sample Kolmogorov-Smirnov test and independent t test, with a significance level of P < or = 0.05. Although the mean (+/- standard deviation) dye leakage in the BeeFill thermoplasticized injection group was less than that in the lateral condensation group (1.497 +/- 0.7 vs. 2.521 +/- 1.733), there was no significant difference between the experimental groups on the parametric independent t-test (P = 0.209).

A study of the relation between erosion and microhardness of root canal dentin.

OBJECTIVE: The aim of this study was to find a relation between erosion and microhardness of root canal dentin after irrigation with different canal irrigants. STUDY DESIGN: Seventy-two single-canal human premolar teeth were selected and enlarged by rotary Protaper files. The middle part of each root was transversely sectioned to a 4-mm slice. The initial microhardness values of intact specimens were measured at depths of 100 microm and 500 microm from the pulp-dentin interface using a Vickers microhardness tester. the specimens were divided into 6 groups of 12 specimens and were treated as follows: 1: 2.6% NaOCl, 2: 17% EDTA (5 minutes) then 2.6% NaOCl (5 minutes), 3: 17% EDTA (1 minute) then 2.6% NaOCl (1 minute), 4: MTAD (5 minutes), 5: 2% Chlorhexidine (5 minutes), and 6: saline (control), respectively. Posttreatment microhardness values were obtained in the same manner as the initial ones. Afterwards, the specimens were prepared for scanning electron microscopy analysis. The amount of dentin erosion was examined. RESULTS: Group 2 showed the most erosive effect on dentin (P < .0001) along with the least decrease of dentin microhardness at depth of 100 microm, whereas MTAD showed the most reduction of dentin microhardness and less erosive effect on dentin. CONCLUSION: It can be concluded that erosion is not the main factor in decreasing the dentin microhardness, whereas the amount of irrigant penetration might be the main cause.

Canal-centring ability of three rotary file systems in simulated curved canals: a comparative study.

OBJECTIVE: To compare the canal-centring ability of M two , ProFile and RaCe rotary files, in simulated curved canals. MATERIALS AND METHODS: About 30 simulated canals were prepared by M two , ProFile and RaCe rotary files. Pre and post-operative pictures were super-imposed and transportations recorded. Measurements were carried out at five different points: Canal orifice (O); half-way to the orifice in the straight section (HO); the beginning of the curve (BC); the apex of the curve (AC); the end point (EP). Intra- and inter-group comparisons were carried out by Wilcoxon;s signed ranks test and Kruskal-Wallis test respectively, using SPSS 14.0 software. RESULTS: ProFile did not change canal centricity in any point. RaCe kept centricity at HO, BC, AC and EP. M two changed canal centricity in points BC, AC and EP. M two group kept the centricity significantly less than the other two groups at BC (P = 0.004), AC (P = 0.015) and EP (P = 0.01). There was no significant difference between these three rotary files at HO. However, the difference between RaCe, M two and ProFile was significant at O (P = 0.015). CONCLUSION: ProFile and RaCe rotary files remained better centred than M two rotary files.

Endodontic Treatment of a Maxillary First Premolar with Type IV Buccal Root Canal: A Case Report.

The maxillary first premolar may present large number of anatomic variations. The clinician should be aware of the configuration of the pulp system. Maxillary first premolars usually have two canals. The incidence of three canals in these teeth is quite rare. This case report presents the diagnosis and clinical management of a maxillary first premolar with two distinct canals in the apical third of buccal root (type IV), drawing particular attention to tactile examination of all the canal walls.

Comparison of extracted teeth and simulated resin blocks on apical canal transportation.

INTRODUCTION: We aimed to compare apical canal transportation of extracted teeth and two types of simulated resin blocks. MATERIALS AND METHODS: Mesiobuccal root of extracted maxillary molars, high hardness simulated resin blocks (Knoop hardness=40) and low hardness simulated resin blocks (Knoop hardness=22) were prepared with K-files using step-back technique (n=15 canals in each group). Double exposure radiographic technique was used for extracted teeth. Simulated resin blocks were stabilized and scanned before and after preparation. Pre and post-preparation pictures were superimposed and apical transportation was measured. The data were analyzed statistically using ANOVA and Tukey HSD tests. RESULTS: There was no significant difference in apical canal transportation between extracted teeth and high hardness resin blocks (P>0.05). Low hardness resin blocks showed more apical transportation than the other groups (P<0.05). CONCLUSION: Under the conditions of this study, apical canal transportation for extracted teeth and high hardness simulated resin blocks were similar.

Technical quality of root canal treatment performed by undergraduate dental students.

INTRODUCTION: This study was carried out to evaluate the technical quality of root canal treatment (RCT) performed by undergraduate dental students at the Islamic Azad University in Tehran, Iran. MATERIALS AND METHODS: Four-hundred records of patients who had received RCT at faculty of dentistry, between the years 2004-2006 were evaluated. For each treated tooth at least three periapical x-rays were assessed: preoperative, working length measurement, and postoperative. Evaluation of root canal filling was based on two variables: length and density. The filling length was recorded as adequate, under- or overfilled. Density of filling was recorded as poor or adequate. Fillings with adequate length and density were recorded as acceptable. Detected iatrogenic errors were: ledge formations, root perforations, furcation perforations, strip perforations and presence of fractured instruments. Results were evaluated statistically using one-way ANOVA and Chi-square analysis. RESULTS: Out of the 400 teeth, 50.5% had at least one of the mentioned errors. Acceptable filling was observed in 32.5% of all studied teeth. Ledge was found in 17.5% of the teeth. Canal curvature was the most important factor associated with ledge formation (P<0.05). CONCLUSION: The technical quality of RCT performed by undergraduate dental students using step-back preparation and cold lateral condensation was classified as acceptable in 32.5% of the cases.