A Study on Biocompatibility of Three Endodontic Sealers: Intensity and Duration of Tissue Irritation

Introduction: Several studies have evaluated the inflammatory reaction triggered by Epiphany (EPH), a contemporary endodontic sealer. However, they used conventional parameters, which need additional analysis to better understand the reactions induced by this sealer compared to other traditional sealers. Methods and Materials: The intensity and time span of tissue irritations for three endodontic sealers were assessed by inflammatory reactions, fibrous capsule measurement and mast cell counts. Tubes containing freshly mixed EPH, AH plus (AHP) and Endofill (ENF) were subcutaneously implanted into the backs of 28 Wistar rats. The side wall of the tube was used as the control. At 14, 21, 42 and 60 days, the connective tissue surrounding the implants (n=7) was stainedfor histopathological analysis. The Friedman test was applied to compare the results. The level of significance was set at 0.05. Results: At days 14 and 21, a significant difference among the groups was observed, with the ENF showing the worst tissue response (P<0.001). ENF remained the most aggressive sealer at 42 and 60 days, compared with EPH (P<0.05). No differences were found for the fibrous capsule thicknesses among the groups in each period. The number of mast cells per field did not show difference among the sealers at 21 and 60 days. Conclusions: EPH and AHP elicited similar patterns of irritation, as demonstrated by the inflammatory scores and fibrous capsule thicknesses. ENF caused the highest degree of tissue damage. The increase in mast cell counts observed during the early and late periods shows the possibility of late hypersensitivity to the test materials

Effects of bleaching agents and adhesive systems in dental pulp: a literature review

The dental pulp may be exposed to several irritants that are potentially noxious to the health and functions of this tissue. Each type of irritant or injury has different effects on the pulp, which are generally characterized by acute inflammation, chronic inflammation or necrosis. Common examples of irritants are dental caries, cavity preparation procedures, traumatic injuries, and chemical substances like bleaching agents and adhesive systems. The present study aimed to review the current knowledge about the effect of bleaching agents and adhesive systems in the human dental pulp. The review covered literature from 2004 to 2009, and only relevant manuscripts were included. Hand search of the references completed the review. Based on literature review, it may be concluded that all dental procedures associated with bleaching agents or adhesive systems involve risks to cause pulp damage. However, these risks can be minimized if the causal factors were known and avoided

Effects of bleaching agents and adhesive systems in dental pulp: a literature review

tal pulp may be exposed to several irritants that are potentially noxious to the health and functions of this tissue. Each type of irritant or injury has different effects on the pulp, which are generally characterized by acute inflammation, chronic inflammation or necrosis. Common examples of irritants are dental caries, cavity preparation procedures, traumatic injuries, and chemical substances like bleaching agents and adhesive systems. The present study aimed to review the current knowledge about the effect of bleaching agents and adhesive systems in the human dental pulp. The review covered literature from 2004 to 2009, and only relevant manuscripts were included. Hand search of the references completed the review. Based on literature review, it may be concluded that all dental procedures associated with bleaching agents or adhesive systems involve risks to cause pulp damage. However, these risks can be minimized if the causal factors were known and avoided

Influence of calcium hydroxide on marginal leakage of endodontically treated teeth

Aim: To evaluate the influence of residual calcium hydroxide (CH) intracanal medication considering two dye leakage locations (apical foramen and middle root canal third) by quantifying the diffusion of India ink in length and depth. Methods: After biomechanical preparation, 72 single-rooted bovine teeth were divided into two groups in which half was filled with a CH and saline paste. After 7 days, the medication was removed and the canals in both groups were filled. Half of the samples had the apical third and part of middle third removed for infiltration of India ink at the middle third (MTI), while the rest were infiltrated at the apical foramen (AI). The following experimental groups were formed (n = 18 each): A1 - CH-medicated + AI, A2 - CH-medicated + MTI, B1 - non-medicated + AI, B2 - non-medicated + MTI. For evaluation of dye leakage, the experimental specimens were cross-sectioned, photographed and had the infiltration perimeter measured using the Image Tool 3.00 software. The Mann-Whitney U-test was used for statistical analysis (p <0.05). Results: The lowest values of dye penetration in length and depth were found in the groups receiving intracanal medication (A1 and A2). Conclusions: Lower dye penetration in length and depth at the two different locations was observed in the canals with residual CH intracanal medication

Influence of calcium hydroxide on marginal leakage of endodontically treated teeth

evaluate the influence of residual calcium hydroxide (CH) intracanal medication considering two dye leakage locations (apical foramen and middle root canal third) by quantifying the diffusion of India ink in length and depth. Methods: After biomechanical preparation, 72 single-rooted bovine teeth were divided into two groups in which half was filled with a CH and saline paste. After 7 days, the medication was removed and the canals in both groups were filled. Half of the samples had the apical third and part of middle third removed for infiltration of India ink at the middle third (MTI), while the rest were infiltrated at the apical foramen (AI). The following experimental groups were formed (n = 18 each): A1 CH-medicated + AI, A2 CH-medicated + MTI, B1 non-medicated + AI, B2 non-medicated + MTI. For evaluation of dye leakage, the experimental specimens were cross-sectioned, photographed and had the infiltration perimeter measured using the Image Tool 3.00 software. The Mann-Whitney U-test was used for statistical analysis (p<0.05). Results: The lowest values of dye penetration in length and depth were found in the groups receiving intracanal medication (A1 and A2). Conclusions: Lower dye penetration in length and depth at the two different locations was observed in the canals with residual CH intracanal medication

Qualitative Analysis after Instrumentation Using Manual Stainless Steel and Rotary Nickel Titanium Instruments

Objective: To compare qualitatively the instrumentation (areastouched by the endodontic instruments) with manual stainless steeland rotary nickel titanium files.Method: 32 mesiobuccal roots of maxillary molars with a singlecanal and a single apical foramen were examined in vitro. Thecanals were instrumented by the crown-down technique using Ktypefiles and taper .04 Profile files, obtaining a surgical diametercorresponding to a #30 instrument. Next, impression material wasinjected into the root canals. After material setting, the teeth weredecalcified to obtain canal impression. To evaluate the quality ofroot canal instrumentation, the images of the impressions weretransmitted to a 29-inch tv using a video camera coupled to anoperative microscope at ×20 magnification and moderate lightintensity. The examined surfaces were classified as EXCELLENT(smooth surfaces indicating that the walls were touched by theinstrument), GOOD (surfaces with irregularities) and REGULAR(surfaces with irregularities, presence of anatomic complexities,like isthmuses, accessory canals, delta, etc).Results: The analysis of the root thirds and surfaces showed apredominance of the REGULAR classification of instrumentationfor both types of instruments. The worst results were found on thepalatal surface and apical third.Conclusion: There was no statistically significant difference(p>0.05) between the manual stainless steel and rotary nickeltitanium instrumentation techniques when the impressions of theroot thirds and surfaces were analyzed qualitatively

Evaluation of Intracanal Post Removal Using Ultrasound

The aim of this study was to determine the effect of ultrasonic vibration on the force necessary to remove pre-fabricated and anatomic and cast posts. Two hundred and forty teeth were divided into two groups. In group I, a 0.8-mm metallic pre-fabricated post, UnimetricMaillefer, was utilized; in group II, cast copper-aluminum alloy posts measuring 0.8, 1.0 and 1.2 mm in diameter were used. The root canals were prepared in three different diameters: 0.8, 1.0 and 1.2 mm, with a length of 10 mm. The posts were cemented with glass monomer cement resulting in 20 specimens for each subgroup. Half of the sample was submitted to ultrasonic vibration for 3 min, while the other half did not receive any vibration. The specimens were submitted to traction in a universal testing machine. The results were analyzed by non-parametric Mann-Whitney U, Wilcoxon and Kruskal-Wallis tests. The application of ultrasonic vibration significantly reduced the retention provided by the glass ionomer cement in the fixation of intracanal posts. The ultrasonic action was effective in both pre-fabricated and anatomic and cast posts. The effectiveness of the ultrasonic vibration was not related to the cementation line or the diameter of the post

Morphometric evaluation and planning of anticurvature filing in roots of maxillary and mandibular molars

This study aimed to guide the planning of anticurvature filing using pre-determined anatomical points on teeth to establish directions for proper implementation of the technique. Two hundred digital periapical radiographs of human molar teeth were selected and divided into two groups (n = 100): MX (maxillary) and MD (mandibular) molars. Mesiobuccal roots were considered for the MX group and mesial roots for the MD group. Pre-determined anatomical points required for planning the anticurvature filing on the root canal path were located, and the distances between these points obtained. The anticurvature filing was simulated in two different protocols for each group, and the region of dentin removal and the remaining dentin thickness were measured in the safety and danger zones of the root canals. Statistical analysis was carried out at a significance level of 5%. The distances between the anatomical points and the thickness of remaining dentin showed significant differences when the two groups were compared (p < 0.001). No significant differences were found between the two experimental groups regarding the area of dentin removal at the root region, but differences were detected in comparison with dentin removal at the crown (p < 0.001). In terms of wear produced after simulation of both anticurvature filing protocols, significant differences were verified for all regions, except for the dentin remaining at the danger zone. The radiographic location of anatomical points allows for planning and implementation of controlled and efficient anticurvature filing and can be performed in the same manner for maxillary and mandibular molars

Evaluation of intracanal post removal using ultrasound

The aim of this study was to determine the effect of ultrasonic vibration on the force necessary to remove pre-fabricated and anatomic and cast posts. Two hundred and forty teeth were divided into two groups. In group I, a 0.8-mm metallic pre-fabricated post, Unimetric-Maillefer, was utilized; in group II, cast copper-aluminum alloy posts measuring 0.8, 1.0 and 1.2 mm in diameter were used. The root canals were prepared in three different diameters: 0.8, 1.0 and 1.2 mm, with a length of 10 mm. The posts were cemented with glass monomer cement resulting in 20 specimens for each subgroup. Half of the sample was submitted to ultrasonic vibration for 3 min, while the other half did not receive any vibration. The specimens were submitted to traction in a universal testing machine. The results were analyzed by non-parametric Mann-Whitney U, Wilcoxon and Kruskal-Wallis tests. The application of ultrasonic vibration significantly reduced the retention provided by the glass ionomer cement in the fixation of intracanal posts. The ultrasonic action was effective in both pre-fabricated and anatomic and cast posts. The effectiveness of the ultrasonic vibration was not related to the cementation line or the diameter of the post