IG-File: un nuovo strumento per l’ottimizzazione della detersione canalare e per la misurazione del diametro apicale

Biocompatibility of three different root canal sealers, experimental study

OBJECTIVES

This study was assessed the biocompatibility of three different root canal sealers (Well-Root St, GuttaFlow Bioseal, and AH-Plus) following implantation in rat subcutaneous tissues, using histopathological immunohistochemical analysis.

METHODS

Four groups of eighty-four male rats each underwent subcutaneous dorsal implantation of a polyethylene tube, either empty or filled. Tissues were collected, fixed, and processed for histological analysis after 7, 15, and 30 d. Slides were photographed and digitally processed to identify lymphocytes and macrophages using Cluster of differentiation 3 (CD3) and cluster of differentiation 68 (CD68) markers, respectively. P was set at 0.05, when lymphocyte and macrophage infiltration was compared between groups and observation times using one-way analysis of variance (ANOVA).

RESULTS

Histopathological analysis of all groups revealed an inflammatory reaction followed by the emergence of a fibrous capsule after 7 days. After 30 days, the thickness of the fibrous capsule and the inflammatory response subsided. CD3 staining for immunohistochemical analysis revealed that the AH-Plus group had the highest mean percentage of lymphocyte infiltration at 7 and 15 days, followed by the Well-Root St, GuttaFlow Bioseal, and Control groups. After 30 days, no discernible difference was observed between the groups in terms of the mean percentage of lymphocyte infiltration. After 7, 15, and 30 days, there was a significant difference in the mean percentage of macrophage infiltration across the groups, as demonstrated by CD68 staining. After 7, 15, and 30 days, the AH-Plus group had the highest mean percentage of macrophage infiltration, followed by the Well-Root St. and GuttaFlow Bioseal groups, while the control group had the lowest mean percentage.

CONCLUSION

All observational periods showed minimal inflammatory reactions to GuttaFlow Bioseal. After subcutaneous tissue implantation in a rat model, the initial inflammatory reactions to Well-Root St and AH-Plus had abated by day 30, and all tested sealers had outstanding biocompatibility.

Post-Operative Endodontic Pain Management: An Overview of Systematic Reviews on Post-Operatively Administered Oral Medications and Integrated Evidence-Based Clinical Recommendations

Endodontic treatment comprises the overall management of pre-, intra- and post-operative symptoms, including post-operative endodontic pain, considered as a complication susceptible of chronicization. Post-operative pain is very common and highly unpreventable and has a multi-factorial etiology and a potential pathogenic link to the acute inflammation of the periapical area, secondary to localized chemical, mechanical, host and/or microbial damage occurring during endodontic treatment. Considering the multitude of heterogeneous technical and pharmacological approaches proposed to control post-operative endodontic pain, the present study primarily comprised an overview of systematic reviews of systematic reviews of randomized clinical trials, summarizing findings on post-operatively administered oral medications for post-operative endodontic pain control, in order to note the most effective type and dosage of such drugs. Secondarily, a narrative review of the current evidence on technical solutions to be observed during endodontic treatment procedures, to control post-operative pain, was conducted to provide integrated evidence-based clinical recommendations for optimal post-operative endodontic pain management.

Development and Analysis of a Hydroxyapatite Supplemented Calcium Silicate Cement for Endodontic Treatment

Aim: To develop an endodontic cement using bovine bone-derived hydroxyapatite (BHA), Portland cement (PC), and a radiopacifier. Methods: BHA was manufactured from waste bovine bone and milled to form a powder. The cements were developed by the addition of BHA (10%/20%/30%/40% wt), 35% wt, zirconium oxide (radiopacifier) to Portland cement (PC). A 10% nanohydroxyapatite (NHA) cement containing PC and a radiopacifier, and a cement containing PC (PC65) and a radiopacifier were also manufactured as controls. The cements were characterised to evaluate their compressive strength, setting time, radiopacity, solubility, and pH. The biocompatibility was assessed using Saos-2 cells where ProRoot MTA acted as the control. Compressive strength, solubility and pH were evaluated over a 4-week curing period. Results: The compressive strength (CS) of all cements increased with the extended curing times, with a significant CS increase in all groups from day 1 to day 28. The BHA 10% exhibited significantly higher CS compared with the other cements at all time points investigated. The BHA 10% and 20% groups exhibited significantly longer setting times than BHA 30%, 40% and PC65. The addition of ZrO₂ in concentrations above 20% wt and Ta₂O₅ at 30% wt resulted in a radiopacity equal to, or exceeding that of, ProRoot MTA. The experimental cements exhibited relatively low cytotoxicity, solubility and an alkaline pH. Conclusions: The addition of 10% and 20% BHA to an experimental PC-based cement containing 35% ZrO₂ improved the material’s mechanical strength while enabling similar radiopacity and biocompatibility to ProRoot MTA. Although BHA is a cost-effective, biomimetic additive that can improve the properties of calcium silicate endodontic cements, further studies are now warranted to determine its clinical potential.

Root Canal Cleaning after Different Irrigation Techniques: An Ex Vivo Analysis

Background and Objectives: The endodontic space is a complex area on both micro and macro levels; therefore, traditional irrigation techniques may not guarantee a complete cleaning of such a complicated tridimensional system. The presented ex vivo study aimed to evaluate root canal cleanliness, obtained through an equal volume of traditionally applied sodium hypochlorite (NaOCl), compared to ultrasonically activated NaOCl and ultrasonically activated NaOCl that had undergone intracanal heating NaOCl. Materials and Methods: A total of 60 freshly extracted human mandibular premolars underwent root sample length standardization (18 mm), root canal preparation and, based on the irrigation method employed, were randomly and equally assigned to three study groups, composed of root samples treated with ultrasonically activated NaOCl, ultrasonically activated NaOCl that had undergone intracanal heating and traditionally applied NaOCl. The root specimens were subsequently fixated with 4% buffered formalin solution and decalcified in Morse liquid. A total often 6-micron-thick serial cross-sections were obtained, dyed using hematoxylin and eosin and examined through an optical microscope at 40×, 100×, and 200×. Results: Ultrasonically activated NaOCl that had undergone intracanal heating showed a significantly smaller amount of debris compared to ultrasonically activated and traditionally applied NaOCl groups (p value < 0.05). Conclusions: Root canal cleanliness saw significant enhancements by ultrasonically activated NaOCl that had undergone intracanal heating.

Effect of herbal and chemical solution in tissue dissolution by using conventional irrigation and sonic irrigation system

Introduction:

An essential part of root canal cleaning is irrigating the system to remove any remaining debris and tissue remains. The purpose of root canal therapy is to shape and clean the endodontic space, reduce the bacterial burden, and remove the pulp tissue. In this research, several irrigation solutions with and without sonic irrigation were evaluated to see how quickly tissue dissolves.

Method:

A tissue sample was taken from a cow (68 ± 3 mg) with no statistically significant difference between groups. All five test tubes in each group were immersed in irrigant, and each group contained one subgroup with five test tubes. Separate weights were recorded for every irrigant that had been passed through the filter paper. Thus, the quantity of pulp dissolved by different irrigating solutions was quantified using a filtering technique.

Results:

It was revealed that there was a substantial difference between the groups. Sonic and non-sonic irrigation of sodium hypochlorite resulted in a substantial difference in tissue disintegration.

Conclusion:

This research found that sodium hypochlorite was more effective than EDTA and saline in dissolving pulp. Despite several studies claiming that neem has potent antibacterial activities, tissue dissolution has not been shown in experiments using this herb.

An innovative technique to safely perform active cleaning in teeth with open apices: CAB technique

The current study aims to evaluate in vitro the extrusion of NaOCl, using an artificial root canal with an open apex, using different canal irrigation protocols. For this study, a transparent artificial root canal was used. The apex was shaped to be oversized and irregular in form. After root canal mechanical shaping, the artificial cylindrical chamber, which was made below the large apical foramen, was filled with fuchsine-stained bovine pulp tissue. Afterward, irrigation protocols were carried out and compared regarding their safety with regards to irrigant extrusion. Subsequently, the examiner created two groups, Group A: internal heating associated with ultrasonic activation and Group B: internal heating associated with ultrasonic activation, using the CAB technique. In both the groups, 5.25% sodium hypochlorite solution was used as the irrigant. Regarding assessing the presence or absence of the extrusion, photographs at ×20 were taken and analyzed. For the statistical analysis, a t-test for paired samples was used. Extrusion of irrigant beyond the apex was present only in Group A. The main objective of endodontic treatment is the removal of damaged tissues and bacteria. For this reason, active cleaning is crucial in all endodontic treatment cases. Internal heating followed with ultrasonic activation while using the CAB technique was an effective and safe technique to ensure no irrigant extrusion beyond the open apex.

A novel modified obturation technique using biosealers: An ex vivo study

Background:

The root canal anatomy is a complex space, and using a single-cone obturation technique does not guarantee a complete filling.

Aim:

This research aimed to evaluate the actual temperature of the biosealer during the obturation phase inside the root canal using a new hot technique. In addition, this study evaluated the penetration depth of the biosealer inside dentinal tubules.

Setting and Design:

The current study was concluded on two ex vivo experiments; the former tested the temperature evaluation. The latter examined the penetration depth of the biosealer.

Materials and Methods:

In this study, 42 sec mandibular premolars were used, and two experiments were carried out. In the first experiment, two premolars were utilized, and two thermocouples of K-type for each tooth were used. During the second experiment, the penetration depth of the biosealer was examined, 40 teeth were selected. Root canals were prepared then divided into two obturation groups: A, gutta-percha, and biosealer with single-cone technique and B, gutta-percha, and biosealer with a newly proposed obturation method. Confocal laser scanning was used to assess the penetration of the sealer.

Statistical Analysis Used:

In the first experiment, the Bonferroni method was performed to compare the temperature data. The tests used in the second experiment were Shapiro–Wilk's test, Kruskal–Wallis, and Mann–Whitney tests.

Results:

The first experiment results showed that the heat does not reach the apical third using the new obturation method. In the second experiment, the results showed in Group B significantly higher biosealer penetration into the dentinal tubules as compared to Group A (P < 0.05).

Conclusions:

The highest level of penetration of the biosealer in the dentinal tubules was observed in the group of the new obturation method, and the last apical 3 mm remained at 37° using this novel hot modified technique providing no risk of chemical alteration of the biosealer.

Management of Severe Curvatures in Root Canal Treatment with the New Generation of Rotating Files Using a Safe and Predictable Protocol

Objective:

The aim of this work was to show the management of severe curvatures done with the new generation of rotating files through a safe and predictable protocol.

Methods:

Three clinical cases were described. A safe protocol was explained using the latest generation of rotating files for the shaping of the anatomy of complex root canals. All the cases presented 90°, 45° curvatures and/or double curvatures.

Results:

The instrumentation of canals increased their surface area and volume. All the cases with 90° and 45° curvatures were optimally shaped.

Conclusion:

With the help of rotating files in the martensitic alloy, it is possible to work safely, while avoiding the risk of file separation, even in root canals with severe curvatures, thus achieving success even in complex clinical cases.

The IG- file use to Gauge the Apical Diameter in Endodontics: An In Vitro Study

Aim:

The aim of this study was to evaluate the efficacy of the IG-file, a new instrument designed for apical diameter gauging.

Materials and Methods:

After shaping with F1 Universal Protaper, 60 roots were randomly divided into two groups and assigned to two operators, One Expert in Endodontics (EO) and One Unexpert (UO).

In each sample, after canal curvatures have been detected, the apical diameters were measured with the IG-file and the K-NiTi. The results were compared with the reference value obtained by retrograde apical gauging. The data were statistically analyzed.

Results:

Among 60 samples, 10% of errors were recorded when the IG-files were used; in the K-NiTi group the incorrect measurements were 70%.

In both groups (expert and unexpert) the IG-file measurements were more accurate than the K-NiTi (90 vs 33 and 90 vs 26,7). The differences were statistically significant.

In curved canals, the difference between measurement rates performed with both instruments was statistically significant (85,7% IG-file vs 28,6% K-NiTi) as well as for the samples without curvatures (92,3% IG file vs 30,8% NiTi file).

In root canals without curvatures overestimation errors in K-NiTi file group are more frequent than underestimation errors. This difference was statistically significant.

Conclusion:

A proper gauging of the apical diameter has a key role in endodontic therapy; an incorrect measurement can lead to clinical failures. This “in vitro” study highlights that IG-file improves measurement accuracy independently from clinician experience. Furthermore, in curved canals, the IG-file is more accurate than K-NiTi.

The Effect of Different Cleaning Protocols on Post Space: A SEM Study

Aim. Purpose of the present paper is to analyze the efficiency of different post-space irrigation protocols. Methods. 28 single rooted teeth were endodontically treated. After post-space preparation every sample was assigned to one of three experimental groups and to one control group. In each group different irrigation protocols were performed as follows: EDTA (Group A), 37% orthophosphoric acid (Group B), and EDTA + 37% orthophosphoric acid with ultrasounds activation (Group C). In the control group (Group D) the irrigate association was not activated by ultrasounds. Three zones (coronal, middle, and apical) of each sample were analyzed by using Scan Electron Microscopy (SEM) without any metallization procedures. The presence of smear layer on the canal surface was qualitatively evaluated by applying Serafino's score with values included between 0 and 2. Results. The results of the research showed how Group C recorded the better results (0.81 ± 0.72). Group A and Group B showed lower mean scores (1.06 ± 0.69 and 1.08 ± 0.77); Group D showed the lowest mean score of 1.30 ± 0.69. The SEM observation analysis demonstrated how the smear layer presence decreased in the crown-apical direction. Conclusions. The different post-space treatments statistically determine significant differences on the dentinal surfaces cleansing. The absence of ultrasonic activation lowers the cleansing efficacy of endocanalar irrigants, showing sensible differences among each post-space zone.

Temperature Profiles Along the Root with Gutta-percha Warmed through Different Heat Sources

OBJECTIVES

To evaluate temperature profiles developing in the root during warm compaction of gutta-percha with the heat sources System B and System MB Obtura (Analityc Technology, Redmond, WA, USA). Thirty extracted human incisor teeth were used. Root canals were cleaned and shaped by means of Protaper rotary files (Dentsply-Maillefer, Belgium), and imaging was performed by micro-CT (Skyscan 1072, Aartselaar, Belgium).

METHODS

Teeth were instrumented with K-type thermocouples, and the roots were filled with thermoplastic gutta-percha. Vertical compaction was achieved through the heat sources System B and System MB, and temperature profiles were detect-ed by means of NI Dac Interface controlled by the LabView System. With both heat sources, higher temperature levels were recorded in the region of the root far from the apex. When the warm plugger tip was positioned at a distance of 3 mm from the root apex, temperature levels of about 180°C were used to soften gutta-percha, and no statistically significant differences were observed between peak temperatures developed by the two heating sources at the root apex. However, a temperature level higher than 40°C was maintained for a longer time with System MB.

RESULTS

Statistically significant differences were observed in peak temperature levels recorded far from the root apex. Thus, with a temperature of about 180°C and the warm plugger positioned at 3 mm from the root apex, both heating sources led to a temperature slightly higher than 40°C at the apex of the root, suggesting that the gutta-percha was properly softened.

SIGNIFICANCE

A temperature level higher than 40°C was maintained for a longer time with System MB, thus providing an ad-equate time for warm compaction of the gutta-percha.