The solubility, pH value, chemical structure, radiopacity, and cytotoxicity of four different root canal sealers: an in vitro study.

OBJECTIVE: The aim of this study was to investigate solubility, pH value, chemical structure, radiopacity, and cytotoxicity of AH Plus BC, TotalFill BC, AH Plus, and AH Plus Jet sealers. MATERIALS AND METHODS: Cytotoxicity analysis with direct and extraction tests at 3 different concentrations (1:1, 1:2, 1:4 v/v%) and time (24 h, 48 h, and 72 h) on Saos-2, PdLF, and THP-1 cell lines, chemical structure with scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX) analysis, solubility, pH, and radiopacity values of AH Plus BC, TotalFill BC, AH Plus, and AH Plus Jet were evaluated. For statistical analyses of the groups, repeated measures, factorial, and one-way ANOVA tests were used. The statistical significance level was set at p < .05. RESULTS: Resin-based sealers showed higher cytotoxicity values than the bioceramic-based sealers (p < 0.05). Time and concentrations were effective on the cell viabilities for cell lines. Higher peaks of calcium were detected bioceramic-based sealers and higher amount of zirconium was detected in AH Plus BC (p < 0.05). AH Plus BC showed similar radiopacity value with AH Plus, AH Plus Jet, whereas TotalFill BC showed the lowest radiopacity (p < 0.05). Bioceramic-based sealers had higher pH values in all experiment periods, and the difference between resin- and bioceramic-based sealer groups was significant (p < 0.05). However, the solubility values of the tested root canal sealers revealed no differences (p > 0.05). CONCLUSIONS: The newly produced AH Plus BC Sealer showed similar properties with TotalFill BC, and their biological properties were better than AH Plus and AH Plus Jet. CLINICAL RELEVANCE: AH Plus BC could be a possible alternative to other bioceramic- or resin-based sealers.

The effect of two different root canal sealers on treatment outcome and post-obturation pain in single-visit root canal treatment: A prospective randomized clinical trial.

AIM: This randomized clinical trial aimed to evaluate and compare the effect of mineral trioxide aggregate (MTA)-based bioceramic- and resin-based sealers on the incidence and intensity of post-obturation pain and treatment outcome in asymptomatic vital molar teeth in single-visit root canal treatment. METHODOLOGY: One hundred asymptomatic mandibular molar teeth with vital pulp were randomly assigned into two groups according to the sealer used: MTA Fillapex or AH Plus sealer. WaveOne Gold instruments were used for root canal preparations. Root canals were obturated with WaveOne Gold gutta-percha cones corresponding in size and taper to the last instrument used. MTA Fillapex was used in the first group and AH Plus was used in the second group as the root canal sealer. The effects of age, gender, tooth types and the level of root canal filling on the treatment outcome were evaluated after 1 and 2 years. Postoperative pain at 6, 12, 24, 48, 72 h, 4, 5, 6, 7 and 30 days after root canal treatment was measured with the Numerical Rating Scale. Chi-square test was used for the treatment outcome and Mann-Whitney U, chi-Square and Spearman correlation analyses were used for postoperative pain. α = .05 was the level of significance. RESULTS: Twelve patients did not complete the 2-year follow-up and the study finished with 88 patients. In the MTA Fillapex group 41 correct, one short, two extruded, and in the AH Plus group 40 correct, one short and three extruded root canal fillings were detected. No significant differences were observed between the first- and second-year treatment outcomes between the groups (p > .05).There was no association between age, gender, tooth number, root canal filling length and the treatment success in all evaluated teeth (p > .05). The differences between the groups in terms of postoperative pain incidence and intensity at all time-points were not significant (p > .05). There was no correlation between the age and postoperative pain (p > .05), but pain was statistically higher in women (p < .05). CONCLUSIONS: Mineral trioxide aggregate Fillapex showed similar success rate and post-obturation pain incidence and intensity as AH Plus sealer and can be used as a root canal sealer in asymptomatic mandibular molars with irreversible pulpitis.

Quality of root canal treatment performed by undergraduate students using nickel-titanium reciprocating versus hand instruments.

PURPOSE: To compare the technical quality of root canal treatment (RCT) depending on the incidence of procedural errors performed by undergraduate students using nickel-titanium reciprocating and conventional hand instrumentation techniques, and to assess the impact of case difficulty and localization of the teeth (maxillary or mandibular molars). METHODS: Dental records and periapical radiographs of molars that were treated with either hand or reciprocating WaveOne (WO) instruments were evaluated retrospectively. The technical quality of RCTs, the incidence of ledge formation, perforation, instrument fracture, overinstrumentation, underfilling, overfilling, inadequate root canal filling, and the effects of case difficulty and tooth localization were compared using the chi-square test with a significance of 5% (α = 0.05). RESULTS: While overinstrumentation was more frequent in the WO group (247 teeth), the incidence of inadequate root canal fillings was higher in the hand instrumentation group (245 teeth) (p < 0.01). No significant difference was observed in the incidence of other procedural errors (p > 0.05). The number of teeth with acceptable technical quality in preparation and obturation was 172 (69.6%) in the WO group, whereas it was 142 (58%) in the hand instrumentation group, presenting a significant difference between the instrumentation techniques (p < 0.01). Higher technical quality rates were observed with WO instrumentation in the high difficulty category and in maxillary teeth (p < 0.01). CONCLUSION: Higher technical quality in preparation and obturation can be achieved with WO reciprocating instruments and file-matched greater tapered gutta-percha cones. No significant difference was observed between the groups in the incidence of procedural errors except for overinstrumentation and insufficient root canal filling. WO instrumentation and obturation with file-matched greater tapered gutta-percha cones provided better technical quality in the high difficulty category and in maxillary teeth.

YouTube™ as an information source for regenerative endodontic treatment procedures: Quality and content analysis.

BACKGROUND: Regenerative endodontic procedures (REPs) are one of the most important developments in dental practice, and in the era of Covid 19 pandemic, audio-visual contents of YouTube™ could be an information source for dental students, practitioners and patients. The aim of this study was to evaluate the quality, content and the demographics of YouTube™ videos about REPs. METHODS: A search on YouTube™ was performed for REPs using "endodontic regeneration", "pulp regeneration", "regenerative endodontics", "regenerative endodontic procedures", "revascularization" and "revitalization" keywords. Totally 531 videos were found and 60 videos met the inclusion criteria. Following the assessment of the demographic features of the videos and the viewing rate of the videos were calculated. The content of the videos was evaluated based on the selected headings. The quality of the videos was assessed using the video information, quality index (VIQI), Global Quality Score (GQS) and DISCERN. The statistical analysis was performed using Spearman Correlation and linear regression analysis. RESULTS: Majority of the videos about REPs were created by dental professionals (91.7%). The most commonly covered topic was "clinical application" (76.7%). Total content score showed a positive correlation with total VIQI (r = 0.795; p < 0.001) and GQS (r = 0.952; p < 0.001). There were significant relationships between total content score, duration, GQS, total VIQI score and DISCERN. CONCLUSION: The findings revealed that YouTube™ videos about REPs provide predominantly clinical information about patient chairside practice of REPs and they could be considered as a supplementary information source for dental students and practitioners.

A prospective cohort study evaluating the outcome of root canal retreatment in symptomatic mandibular first molars with periapical lesions.

AIM: To evaluate the impact of various predictors on the outcome of root canal retreatment in symptomatic mandibular first molars with periapical lesions after a minimum of 2 years. METHODOLOGY: One hundred and twenty previously root canal treated symptomatic mandibular first molars with periapical lesions which were diagnosed as symptomatic apical periodontitis or acute apical abscess with localized intraoral swelling were included. Root canal retreatment was performed by an experienced endodontist using a standardized treatment protocol. The teeth were followed up clinically and radiographically and the radiographic outcome was assessed using a modified periapical index scale (PAI). The cumulative success proportion and the influence of predictors on the outcome of the root canal retreatment were analysed using Kaplan-Meier analyses and log-rank tests, and the hazard ratios for the predictors were also investigated using Univariate Cox Proportional Hazard regression analysis at a significance level of 5%. RESULTS: Of the 120 teeth, 103 teeth were re-examined with an 85% recall rate. The cumulative success rate was 88% in which 64% were healed and 24% were healing, and failure rate was recorded as 12%. None of the preoperative predictors, including age, gender, soft tissue tenderness, intraoral swelling, size of the lesion, PAI score, apical level and density of root canal filling before root canal retreatment, nor intraoperative predictors, such as active exudate drainage, density of root canal filling after root canal retreatment and restoration type had an influence on the outcome of root canal retreatment (p > .05). The only factor that significantly reduced the success rate of root canal retreatment was the apical level of the root canal filling; when it was more than 2 mm short of the radiographic apex in teeth where apical patency was not established, the success was significantly lower (p = .023). CONCLUSIONS: Root canal retreatment in symptomatic mandibular first molars with periapical lesions resulted in a success rate of 88%. None of the predictors had a significant influence on the outcome, except for the apical level of the root canal filling after root canal retreatment with short root fillings being associated with significantly more post-treatment endodontic disease.

The influence of different NiTi instrumentation techniques on postoperative pain after single-visit root canal treatment.

This study aimed to evaluate the effect of multi-file rotary (Protaper Universal) and reciprocating single-file (Reciproc Blue) root canal preparation techniques on the occurrence of postoperative pain in asymptomatic mandibular molar teeth with large periapical lesions in single-visit root canal treatment (RCT). A hundred and twenty teeth were randomly assigned to two groups: Protaper Universal (PTU) or Reciproc Blue (RB) instruments. Postoperative pain at 6, 12, 24, 48, 72 h and 7 days after obturation was measured. Mann-Whitney U-test was performed to compare the pain scores between the groups and to assess the relation of pain with patients' age and gender. Spearman's rank correlation was utilized to correlate the pain intensity and analgesic intake at different time points. There was no significant difference between the instrumentation techniques regarding postoperative pain at any time points evaluated (P > 0.05). There was a correlation between analgesic intake and intensity of pain (P < 0.05). No statistically significant difference was found among the groups assessed in the study in terms of analgesic intake (P > 0.05).

Impact of root canal curvature and instrument type on the amount of extruded debris during retreatment.

OBJECTIVES: The aim of the current study was to assess whether the amount of extruded debris differs for straight and severely curved root canals during retreatment using H-files, R-Endo, Reciproc and ProTaper Universal Retreatment (PTU-R) files. Additionally, the area of residual filling material was evaluated. MATERIALS AND METHODS: Severely curved (n = 104) and straight (n = 104) root canals of maxillary molar teeth were prepared with WaveOne Primary file and obturated with gutta-percha and AH Plus sealer. Root canal filling materials were removed with one of the preparation techniques: group 1: H-file; group 2: R-Endo; group 3: Reciproc; group 4: PTU-R (n = 26). The amount of extruded material and the area of the residual filling material was measured. The data were analyzed with 2-way analysis of variance (ANOVA) and 1-way ANOVA at the 0.05 significance level. RESULTS: Except for Reciproc group (p > 0.05), PTU-R, R-Endo, and H-file systems extruded significantly more debris in severely curved canals (p < 0.05). Each file system caused more residual filling material in severely curved canals than in straight ones (p < 0.05). CONCLUSIONS: All instruments used in this study caused apical debris extrusion. Root canal curvature had an effect on extruded debris, except for Reciproc system. Clinicians should be aware that the difficult morphology of the severely curved root canals is a factor increasing the amount of extruded debris during the retreatment procedure.

Cyclic fatigue resistance and energy dispersive X-ray spectroscopy analysis of novel heat-treated nickel-titanium instruments at body temperature.

The aim of this study was to evaluate the cyclic fatigue resistance of Dia-X, WaveOne Gold and One Curve files in a water bath at intracanal temperature (35°C). Thirty-nine instruments Dia-X, WaveOne Gold, and One Curve systems (n = 13) were tested in an artificial canal with a curvature angle of 60° and a radius of 3 mm. A water bath setup at a temperature of 35°C was used to simulate the intracanal temperature and time to fracture (TTF) as seconds was recorded. The mean data were analyzed statistically using one-way ANOVA, and post hoc Tukey test (p = .05). The fractured surface of the instruments was examined with scanning electron microscopy (SEM) and chemical composition of the instruments were investigated with energy dispersive X-ray spectroscopy (EDS). Statistically significant differences were detected in TTF values of all the systems as follows: One Curve > WaveOne Gold > Dia-X (p < .05). One Curve instruments demonstrated the highest TTF values in all the tested instruments. The EDS microanalysis revealed similar NiTi composition of on the surface of One Curve, WaveOne Gold, and Dia-X instruments. The novel manufacturing process, including C-wire heat treatment and the variable cross-section of the One Curve files, could be the main factors affecting the fatigue life of the instruments.

Cyclic Fatigue Resistance of Multiused Reciproc Blue Instruments during Retreatment Procedure.

INTRODUCTION: Root canal retreatment procedure may reduce the mechanical resistance of nickel-titanium instruments and increase the frequency of instrument fracture. The aim of the present study was to evaluate the effect of multiuse of Reciproc Blue R25 instruments on cyclic fatigue resistance during retreatment procedure in mandibular molar teeth. METHODS: Forty-eight Reciproc Blue R25 files were included in the study. In control group, 12 new Reciproc Blue R25 instruments were subjected to cyclic fatigue test by using a stainless steel artificial canal with a 90° angle and 3-mm radius of curvatures. In experimental groups, Reciproc Blue R25 files (n = 12) were used to remove the root canal filling (RCF) material of 1, 2, and 3 molar teeth, respectively. Then cyclic fatigue tests of these 36 instruments were performed. The number of cycles to fracture (NCF) and the length of the fractured fragment were calculated for each instrument. Working time for retreatment procedures was determined in seconds with a digital chronometer. The data were analyzed by using one-way analysis of variance followed by post hoc Tukey test and mixed-effect analysis (P = .05). RESULTS: No significant difference was found between NCF values of new and first time used files (P > .05), but NCF values of new and first time used files were significantly higher than those of second and third time used files (P < .05). The second and third time used files revealed no difference (P > .05). As the number of uses increased, the average time for retreatment procedure statistically extended (P < .05). CONCLUSIONS: Reciproc Blue R25 instrument can be used to remove RCF material of 2 molar teeth. However, because of its decreased NCF values, multiple use over 2 molars may not be suggested.

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.