Standard Access Cavities Research Articles

Fracture resistance of postendodontic restoration using self-adhesive bioactive resin and a bulk-fill composite with or without resin-impregnated glass fibers: An in vitro study.

Due to advancements in adhesive technology and the introduction of fiber reinforcement, there has been a paradigm shift towards a more minimally invasive approach in coronal restoration of endodontically treated teeth. This research aimed to evaluate and compare fracture resistance of postendodontic restoration using a self-adhesive bioactive resin and a bulk-fill composite with or without resin-impregnated glass fibers. Mesio-occlusal-distal cavities were prepared on 80 extracted human maxillary premolars. Root canal treatment was completed following standard access cavity preparation. Then, the teeth were divided into two groups based on the composite used for postendodontic restoration. Group I: Bulk-fill composite (Tetric N-Ceram). Group II: Activa BioActive. Group I and Group II were then divided into two subgroups depending on fiber incorporation (n = 20). Subgroup IA: Bulk-fill composite. Subgroup IB: Bulk-fill composite with fiber incorporation. Subgroup IIA: Activa BioActive. Subgroup IIB: Activa BioActive with fiber incorporation. The force required to fracture the teeth was recorded using the universal testing machine. Two-way ANOVA and Tukey's multiple post hoc test. Activa BioActive with fiber incorporation showed the highest mean fracture resistance (988.52N). Bulk-fill composite without fiber incorporation had the least mean fracture resistance (669.87N). Activa BioActive bulk-fill restorative material when used with the incorporation of resin-impregnated glass fibers can be a preferred material of choice for restoring endodontically treated teeth.

Optimizing Root Canal Therapy: An In Vitro Comparative Study of Innovative File Systems on Mandibular Premolar Fracture Resistance.

Root canal therapy is a vital procedure for saving teeth by removing infection and cleaning the complex root canal system. However, a delicate balance exists between thorough cleaning and preserving tooth strength. The study aims to evaluate theinstrumentation effect of three innovative file systems, XP-endo® shaper, Reciproc®, and Self-adjusting file (SAF) on fracture resistance of mandibular premolars. Thirty single-rooted mandibular premolars were collected; a standard access cavity was preparedand the working length was established 1 mm short of the apex.The teeth were randomly divided into three groups(n=10). In Group 1,the shaping of the specimens was achieved using XP-endo® shaper; in Group 2, it was instrumented using Reciproc® file; and in Group3, it was instrumented using SAF. All samples were decoronatedandthe roots were mounted vertically inacrylic resin and subjected to fracture resistance under a universal testing machine. Intergroup analysiswas doneby one-way ANOVAfollowed by Bonferroni posthoc test,which did not report astatistically significant difference (p>0.05). All three testedfile systems were similar in fracture resistance. XP-endo® shaper exhibited better fracture resistance on root canal instrumentation when compared to Reciproc® and SAF although they are not statistically significant.

The Effect of Different Image Processing Techniques on the Measurement Accuracy of Endodontics File Length.

Different software capabilities have been used in digital systems to increase the diagnostic quality of radiographic projections. Considering the availability of different enhancement techniques, it is necessary to determine the suitability of each technique for various diagnostic cases. There is controversy between studies over the effect of different digital enhancement techniques on the accuracy of file length measurements in endodontics. The present in vitro study aimed to determine the effect of the software capabilities on the diagnostic accuracy to determine endodontic file lengths in photostimulable phosphor (PSP) radiographs. In the present in vitro study, standard access cavities were prepared in 44 extracted human single-rooted permanent teeth. An endodontic file was placed in each root canal. PSP sensors were used for digital imaging using the parallel technique. All the images were reviewed on a same monitor; once normally with no software enhancement and once using software manipulations including pseudo-color, sharpness, emboss, and edge enhancement. The distance from the file tip to the rubber stop was measured on the images by an electronic ruler. Significantly, all of the image enhancement techniques presented shorter measurements comparing to the actual length. The results revealed the significant accuracy of the measured error in the pseudo-color enhancement technique compared to other techniques. The results revealed significant differences between the initial measurements (the gold standard) and those made on the manipulated radiographs. In all cases, the measurements were significantly lower than the real values. Therefore, none of these digital enhancement techniques can increase the accuracy of file length measurements significantly. However, manipulation with the pseudo-color option resulted in fewer errors compared to other options and the normal images. Hence, for precise measurements of the endodontic file lengths, pseudo-color processing algorithm can be suggested when using PSP sensors.

A scanning electron microscopic study evaluating the sealing ability of MTA, BiodentineTM, and new light-cure MTA used for furcal perforation repair.

To evaluate and compare the sealing ability of Mineral trioxide aggregate (MTA), BiodentineTM and light cure MTA used for the repair of furcal perforations using scanning electron microscope (SEM). The study sample comprised 45 extracted mandibular molars. The teeth were embedded in modeling wax. Standard access cavities were prepared in each tooth using a round bur and non-end cutting bur with a high-speed handpiece with water spray. Furcal perforations were made on the centre of the pulpal floor of each tooth using a 0.5mm round bur. The teeth were then randomly divided into 3 experimental groups of 15 specimens each based on the materials used to seal the perforation; Group A: MTA; Group B: BiodentineTM; Group C: Light cure MTA. All the sealed perforations were compacted with a moist cotton pellet, and the samples were stored in a closed container for 24 hours to allow the repair materials to set completely. After 24 hours the samples were sectioned longitudinally and the extent of marginal adaptation was measured using scanning electron microscopy. The sealing ability was evaluated by measuring the gap (in microns) between the pulpal floor and the material used for the furcal repair. The overall results showed that the marginal adaptation of light-cure MTA was better than both MTA as well as Biodentine. The mean space between the pulpal floor and the repair material was least for group C (2.29). Tuckey's post hoc test showed that a significant difference (p<0.05) existed between group C and group A & B. Light-cure MTA exbibits good sealing ability to dentin when compared to conventionally used Biodentine and Mineral Trioxide Aggregate. Key words:Calcium silicates, MTA, Biodentinte, New light-cure MTA, Perforation repair.

Evaluation of effect of core build-up materials on fracture resistance of endodontically treated teeth

Background: Restoration of teeth after endodontic treatment is becoming an integral part of reconstructive dentistry. Aim: The aim of this study was to evaluate the effect of different core build-up materials on fracture resistance of endodontic ally treated teeth. Materials and methods:Freshly extracted forty permanent mandibular first molars were selected. Standardized access cavities were prepared, following which mesial canals were prepared up to F2 (8%25) and distal canals up to F3 (9%30)and obturated. The coronal portion of the specimen was altered by removing the mesial wall and retaining buccal, lingual and mesial walls of 2mm and distal 5mm girth.Ten specimens each were rehabilitated with high copper amalgam, type IX GIC, posterior composite and Alkasite as core build-ups. All the specimens were finally rehabilitated with a metal crown. The specimens were tested for fracture resistance using a universal testing machine under oblique (135oto the long axis of teeth) cyclic loading. The number of cycles taken to fracture,and the fracture site was recorded.The results of mechanical cyclic loading to evaluate fracture resistance showed that compositecore endured the maximum number of cycles to fracture followed by amalgam, Alkasite and type IX GIC.To test the statistical significance inthe difference of mean value KICamong four groups, Kruskal-Wallis one-way analysis of variance was applied. Bonferroni’s multiple comparison test was performed to determine which group significantly differed from the others. Results:From the results of this study, the composite was considered to be the best core build-up material. The newer material, Alkasite can bear stress almost to that of amalgam restoration. Conclusion:This studysuggeststhat Alkasite could be used as a core material for restoring the endodontically treated teeth.

Centering Ability of Three Different Reciprocating Rotary Files Using Cone Beam Computed Tomography – In-vitro Study

Background: Centering ability of root canal files is considered to be an imperative factor during root canal instrumentation. Hence it is decided to evaluate and compare the centering ability of Reciprocating rotary files in teeth by means of cone beam computed tomography in vitro condition.&#x0D; Objectives:&#x0D; &#x0D; To evaluate the centering ability of the Reciproc file system in extracted mandibular molar.&#x0D; To evaluate the centering ability of the Reciproc Blue file system in extracted mandibular molar.&#x0D; To evaluate the centering ability of the WaveOne file system in extracted mandibular molar.&#x0D; To compare the above file systems with each other.&#x0D; &#x0D; Methodology: 30 Newly extracted mandibular molars will be considered in the study. Before access opening teeth will be exposed for a pre-instrumentation CBCT scan. After this scanning standard access cavity preparation will be done followed by checking canal patency using 10#K-file. Then teeth will be divided into three groups for root canal instrumentation. Group 1: Instrumentation by using Reciproc file, Group 2: Instrumentation by using Reciproc Blue file, Group 3: Instrumentation by using WaveOne file. For evaluation of centering ability, the equation introduced by Gambill (1996) i.e., (m1 – m2) ÷ (d1 – d2) or (d1 – d2) ÷ (m1 – m2) and (b1-b2) ÷ (l1-l2) or (l1-l2) ÷ (b1-b2) will be used after post instrumentation CBCT scanning. &#x0D; Expected Results: The Reciproc Blue file system is expected to give better results in canal centering ability.&#x0D; Conclusion: Centering ability is considered to be important factor in biomechanical preparation, as it can retain the instruments in centre which is crucial to offer a precise extension, without weakening of the root structure. Different files are used to evaluate and compare the centering ability of instrument by CBCT.

Comparative assessment of apically extruded debris using Protaper Next, Hyflex CM and EdgeFile X7 nickel titanium instruments (An in vitro Study)

Aim: To compare the amount of extruded debris with three endodontic NiTi engine driven systems, Protaper Next, Hyflex CM and EdgeFile X7. Material and Methods: A total number of 42 freshly extracted human premolars were selected. Teeth were divided randomly into three equal groups (14 teeth each group) according to type of Ni-Ti rotary file system; (A) Protaper Next, (B) Hyflex CM and (C) EdgeFile X7. Standard Access cavity prepared and checked for patency using K file #10 and #15. Root canal instrumentation on the single canal lower premolars was done. Debris was collected after root canal instrumentation in pre-weighed Eppendorf tubes. The Eppendorf tubes were weighed 2 times on the analytical balance. First weight: Before instrumentation. Second weight: After evaporation of moisture and irrigant and incubation. Welch test was used for comparison between the three groups. Results: There was no statistically significant difference between the amounts of debris extrusion of the three groups Conclusion: All endodontic rotary instruments tested produced apical extrusion of debris.

Comparative analysis of working length determination using Radiovisiography, Electronic apex locator &amp; Graduated root canal length indicating cone – An in vivo study

Purpose:The present study evaluated accuracy of radiovisiography (RVG), electronic apex locator (EAL)andgraduated root canal length indicating cone (GRCLIC) when used for working length determination. Materials and Methods:Total of 11 patients with 30 maxillary anterior teeth in the age group of 30-60 years scheduled for extraction for periodontal reasons were selected. Standard access cavities were preparedand selected teeth were then subjected to working length determination using three methods and compared with actual canal length determined after extraction. The study groups were as follows: Group 1: Working length determination using RVG Group 2: Working length determination with EAL Propex-II, Dentsply Group 3: Working length determination using GRCLIC Group 4: Actual canal length determined after extraction and 1mm subtracted from it The data was analyzed statistically by ANOVA test to compare the four groups and by unpaired t-test and scheffe’s multiple comparison test group wise. Results:There was no significance difference (p &gt; 0.05) observed between Group 1 (RVG), Group 2 (EAL) and Group 3 (GRCLIC) with Group 4 (AL).Percentage accuracy analysis indicated that GRCLIC method showed maximum accuracy i.e. 96.43% followed by RVG with 96.12% accuracy and EAL with a value of 95.81%. Conclusion: GRCLIC used for calibration of working length produced comparable results with the actual length, thus suggesting that it may be used for root length determination in clinical practice instead of conventional files with less accuracy. Key Words:Electronic Apex Locator, Graduated Root Canal Length Indicating Cone, Radiovisiography, Working length determination

Effectiveness of the static-guided endodontic technique for accessing the root canal through MTA and its effect on fracture strength.

(1) To evaluate the effectiveness of the static-guided (SG) endodontics technique for accessing the root canal through the mineral trioxide aggregate (MTA) and (2) to evaluate the effect of this technique on the fracture strength of teeth. Thirty mandibular premolars were used in the present study. After standard coronal access cavity preparation, root canals were prepared up to size #80 to simulate an immature root apex. White MTA was placed approximately 3 mm below the cementoenamel junction (CEJ), as placed in regenerative endodontic procedures. After the MTA had set, the cavity was restored with a resin composite material. The teeth were randomly divided into two groups (n = 15). In the control group, the composite resin and MTA were removed without any guide. In the SG-access group, a cone beam computed tomography (CBCT) scan was performed, 3D-printed guides were designed and fabricated, and then the composite resin and MTA were removed with a guide. One inexperienced operator performed the removal of the composite resin and MTA in all groups. Pre- and post-operative periapical radiographs were taken. The mishaps and time to penetration to root canal were recorded. After that, the root canals were filled, and the access cavities were restored. The samples were subjected to a fracture strength test. Data were analyzed using Mann-Whitney U, independent samples of T test, and chi-square tests at 95% confidence level (P = 0.05). There were significant differences between the control and SG-access groups in terms of mishaps and time to penetration to the root canal through the MTA barrier (P < 0.05). The SG-access group required the shorter time as compared with the control group. Mishaps did not occur in the SG-access group. The SG-access group exhibited the significantly preserved fracture resistance of the teeth as compared with the control group (P < 0.05). Non-restorable failure occurred more frequently in the control group than in the SG-access group. Within the limitations of the present study, the SG endodontic technique yielded favorable results with respect to time, mishaps, and fracture strength. The static-guided endodontics technique may provide advantages to the clinician for MTA removal.

A Comparative Evaluation of Effects of Conventional and Herbal Irrigants on Working Length Determination by Third Generation Apex Locator–An In Vitro Study

Abstract Introduction The establishment of accurate working length is one of the most critical steps in endodontic therapy from the biomechanical and obturation points of view. Traditionally, the use of radiography and tactile sense methods were used for working length estimation, but recently, the use of electronic apex locator (EAL) has come into existence. The aim was to evaluate the effect of conventional and herbal irrigants on working length determination by Root ZX. Materials and Methods A total of 110 extracted single rooted teeth were taken. Standard access cavities were prepared and samples were randomly divided into 11 groups (n = 10) according to the type of irrigating solutions used. The actual root canal length was measured, and the readings in dry conditions and wet conditions were recorded. The point where Root ZX showed beep was recorded and difference was recorded as well. The recorded data was calculated and statistically analyzed using unpaired t-test. Result In dry conditions, only saline, H2O2, Aloe vera, and green tea gave exact working length using apex locator values. Whereas in wet conditions, only Aloe vera and green tea gave exact working length. Conclusion Although the irrigants and dry conditions influenced the results, Root ZX can be considered to be accurate, and the difference was within the clinically acceptable range and not statistically significant.

Influence of working length determined by three different apex locators on the apical extrusion of debris following the instrumentation with rotary Ni–Ti instrumentation system

Aim: This study aimed to comparatively evaluate the influence of working length (WL) determined by three different electronic apex locators (EALs) on the apical extrusion of debris following the instrumentation with a rotary NiTi instrumentation system. Methodology: Forty extracted human maxillary or mandibular premolar teeth with single root and canal were selected. Standardized access cavities were prepared, and the samples were divided into four groups according to the method used to determine the WL: Group I (n = 10) – actual working length (AL), Group II (n = 10) – Root ZX mini, Group III (n = 10) – CanalPro™, and Group IV (n = 10) – Propex Pixi™. Each specimen was held in a test apparatus to evaluate the apical extrusion of debris during instrumentation. Instrumentation of all the specimens was done using ProTaper Next till the size X3. The apically extruded debris was collected and calculated by subtracting the initial weight of the tube from the weight of the tube containing dried debris. The apically extruded debris weight score was calculated and tabulated and was subjected to statistical analysis using one-way ANOVA and post hoc Tukey test. Results: Group II and Group III exhibited similar results and exhibited significantly less apical extrusion of debris compared to Groups I and IV. Conclusion: WL determined by EAL (Root ZX mini and CanalPro) showed lesser apical extrusion of debris than AL determination.

A comparative evaluation of sealing ability of three perforation repair materials using a field emission gun-scanning electron microscope

Introduction: The study aimed to assess the sealing ability of Biodentine™, ProRoot mineral trioxide aggregate (MTA), and Super-EBA as furcation perforation repair materials using field emission gun-scanning electron microscope (FEG-SEM). Materials and Methods: Thirty-six extracted human permanent mandibular molar teeth were collected and cleaned. Standard access cavity preparation was made, and intentional perforation was created in each of the access cavity-prepared teeth using #12 round bur. The teeth were randomly divided into three groups each containing 12 teeth. The perforations were sealed as follows: Group A with Biodentine™, Group B with ProRoot MTA, and Group C with Super-EBA. The repair materials for all the three groups were evaluated for marginal adaptation using FEG-SEM. Data were statistically analyzed using one-way ANOVA and Tukey's honest significance test. Results: Quantitative FEG-SEM observations illustrated that the mean gap at the dentin–furcation repair material interface was as follows: Biodentine (3.01 ± 0.37 μm), ProRoot MTA (4.98 ± 0.68 μm), and Super-EBA (8.03 ± 0.68 μm). The difference between Biodentine™ and ProRoot MTA was not statistically significant (P > 0.05). Individually, Biodentine and ProRoot MTA showed statistically significant differences when compared to Super-EBA (P Conclusion: The sealing ability of ProRoot MTA and Biodentine™ as a repair material of furcation perforation was better than Super-EBA.

Comparative analysis of microleakage of temporary filling materials used for multivisit endodontic treatment sessions in primary teeth: an in vitro study.

Coronal leakage is an important factor contributing to the failure of endodontic treatment. The use of an efficient temporary restoration between sessions of multiple-visit pulpectomies is irrefutable. Two cements have long been used in endodontics-IRM, which is a reinforced zinc oxide cement and Cavit G, a calcium sulphate based cement. The aim of this study was to compare the microleakage of nano silver containing UDMA-based cements with routinely used zinc oxide and calcium sulphate-based temporary cements in primary teeth. Standardized access cavities of 3 × 3mm were prepared in the sixty caries-free primary molars. The teeth were divided randomly into four groups of 14 teeth each-Group I: IRM, Group II: Cavit G, Group III: Orafil-G and Group IV: Dia-Temp. Temporary restorative materials were applied according to the manufacturer's instructions. The teeth were subjected to thermocycling and then immersed in 0.5% basic fuchsin for 24h. The specimens were sectioned and evaluated under a digital microscope at 20× magnification and were scored for microleakage. The collected data were tabulated and subjected to statistical analysis. Dia-Temp presented the least microleakage values. The highest score for microleakage was shown by IRM followed by Orafil-G and Cavit-G. There was a significant difference between IRM and Diatemp groups (p value = 0.009), and among Orafil G and Diatemp groups (p value = 0.025). Among the four materials tested, Dia-Temp exhibited the best sealing ability and its use is recommended in between sessions of endodontic treatment in primary teeth.

Radiographic evaluation of root canal curvature in mesiobuccal canals of mandibular molars by different methods and its correlation with canal access angle in curved canals: An in vitro study

Aims:The aim of this study is to compare three different methods of measuring root canal curvature and its correlation with canal access angle (CAA) in curved mesiobuccal canals of permanent mandibular first molars.Materials and Methods:Sixty human mandibular first molars were used in this study. Standardized access cavities were prepared. After endodontic access, a size 10 K-file was placed in the mesiobuccal canal extending to the apical foramen, and radiographs were taken. Radiographs of each root canal were taken in buccolingual direction with the long axis of the root perpendicular to the central X-ray beam. After that, the radiographs were scanned with a computer Scanner. The angles were measured using the Schneider method, Weine's method, Lutein's method, and correlated with the CAA method. The angular and linear values used in this study were plotted, and the pertinent measurements were made using the program AutoCAD R12.Statistical Analysis:The resultant values were evaluated statistically using ANOVA test and Pearson correlation and multiple regression analyses (P = 0.001).Results:Lutein's method is as effective as the Schneider's method, Wein's method and CAA. method in evaluating root canal curvature.Conclusions:Scheider/Wein/Luiten method, together with CAA method, may be considered as a reliable guideline for preoperative assessment of canal curvature.

Presentation of gaps around endodontic access cavity restoration by phase contrast-enhanced micro-CT.

To evaluate the feasibility of synchrotron-based phase-contrast (PC) μCT for visualization of the gaps and differentiation between the gaps, restorative, and endodontic materials at the tooth-restoration interface. Standardized access cavities were prepared in human maxillary molars and subjected to materials, simulating endodontic treatment: (1) saline irrigation; (2) NaOCl and 17% EDTA irrigation; (3) same as group 2, followed by application of Ca(OH)2; and (4) same as group 2, followed by application of root canal sealer. The access cavities were cleaned and restored using an etch-and-rinse adhesive and a composite material in multilayering technique. The samples were thermocycled (1000cycles, 5-55°C). Synchrotron-based μCT imaging was performed obtaining absorption and PC μCT images before and after the immersion of the samples into 50% AgNO3. PC μCT images were compared to absorption μCT and conventional optical microscopy images. PC μCT of unstained samples enabled the best visualization of gaps and differentiation of restorative and endodontic materials, contaminating the cavity surface. PC μCT revealed that AgNO3 staining leads to an overestimation of gap size due to anterograde and retrograde AgNO3 infiltration into dentinal tubules and underestimation of large gaps due to lack of AgNO3 penetration. Synchrotron PC μCT imaging enables better visualization of gap and differentiation of materials at the tooth-restoration interface. μCT imaging with AgNO3 staining has shown certain over- and underestimations. Future research should be aimed at incorporating PC μCT imaging of unstained samples for the validation of results obtained with other methods. Contamination of cavity walls with an endodontic sealer or Ca(OH)2 leads to increased gap formation at the tooth-restoration interface.

Effect of several laser systems on removal of smear layer with a variety of irrigation solutions.

To evaluate which laser system is more effective on smear layer removal when distilled water or combination of sodium hypochlorite (NaOCl) and ethylenediaminetetraacetic acid (EDTA) are used as irrigants. Ninety-six human mandibular premolar teeth were used. Standard access cavities were prepared and the root canals were enlarged using ProTaper system to size F4 and divided into two equal groups according to final irrigation solution. In Group 1, distilled water was used, whilst 2.5% NaOCI and 17% EDTA solutions were used in Group 2. Each group was divided into four equal subgroups according to the activation procedure. In Subgroups 1A (Control) and 2A, no activation protocol was applied. In other subgroups, Er:YAG laser using photon-induced photoacoustic streaming (PIPS; 1B and 2B), Nd:YAG laser (1C and 2C) and Er,Cr:YSGG laser (1D and 2D) were applied for the activation. Teeth were split longitudinally and subjected to scanning electron microscopy evaluation. Smear layer was scored at 1000× magnification in all thirds. The data were analysed statistically using Kruskal-Wallis and Mann-Whitney U test post hoc comparisons. The samples irrigated with distilled water had greater smear layer scores when compared with the combination of NaOCl and EDTA (p < .05). The efficacy of smear layer removal increased when using laser systems (p < .05). Smear layer was removed more effectively in the coronal and middle levels compared to the apical level (p < .05). The sequential use of NaOCl and EDTA is significantly more effective than distilled water in smear layer removal. Regardless of the type of irrigant, laser activated irrigation enhances smear layer removal. RESEARCH HIGHLIGHTS: The use of laser systems for activation of NaOCl and EDTA is the most effective method in terms of smear layer removal. Photon-induced photoacoustic streaming technique with Er:YAG laser was the most efficient smear layer removal method regardless of the solution used.

Comparison of root canal length measurement methods in primary teeth

Objectives: The purpose of this study was to evaluate the accuracy of conventional radiography, intraoral digital radiovisiography and electronic apex locator in determining the working length of root canals in primary teeth (in-vivo) and to compare the results with scanning electron microscopy measurements (ex-vivo). Materials and Methods: This study was conducted on 50 primary molar teeth. Standard endodontic access cavity preparations were prepared and the actual length was calculated by calibrated investigators. Working lengths were determined by using conventional radiography, RVG and apex locator in a total of 116 root canals. After the extraction of the teeth, each canal length was determined by using SEM. Data were analysed statistically by using Oneway Anova, Tukey HDS, Student t test and Bonferroni tests. Results: The mean root length measurements with conventional radiography were significantly higher than apex locator, RVG and SEM. The accuracy of apex locator and RVG were higher than conventional radiography in determining the working length in primary teeth. Conclusions: The electronic apex locators provide an acceptable level of accuracy in determining root canal length in primary teeth. Clinical Relevance: The purpose of this study was to evaluate the accuracy of conventional radiography, intraoral digital radiovisiography and electronic apex locator in determining the working length of root canals in primary teeth and,to compare the results with scanning electron microscopy measurements.

Effects of intracanal medicaments and the remaining cavity wall on fracture strength of endodontically treated molars

Objective: The aim of this study was to investigate the effects of the short-term intracanal application of two medicaments on the fracture strength of root-filled molar teeth with different levels of tooth structure loss. Material and Methods: Standard access cavities of totally 84 intact maxillary molar teeth were prepared in 72 teeth and were divided into 3 main groups. Standard access cavities were kept in the first group, while mesio-occlusal-distal cavities (MOD) were prepared in the second and third groups. One-half of the palatinal walls were removed in the third group. Twelve sound teeth were used in the fourth group as control. Each group was then assigned into two subgroups according to the medicament used (n=12): 2% chlorhexidine gel and calcium hydroxide. Samples were stored at 37°C and 100% humidity for 1 week. Then the teeth were inserted into a universal testing machine and vertically loaded (5 mm/min) from the occlusal surface. The data was recorded in Newtons and statistically evaluated using a Univariate ANOVA and a Tukey as post hoc test. Results: A significant difference was found among the test groups (p&lt;0.01). No significant difference was found according to the medicament used (p&gt;0.05), however the number of remaining walls significantly affected the fracture strength (p&lt;0.01). The first group with access cavity showed mostly repairable fractures (60%–80%) whereas the others showed mostly non-repairable fracture patterns (60%–90%). Conclusion: In conclusion, the fracture strength of endodontically treated teeth is related to the structure loss rather than the intracanal medicament used. KeywordsEndodontically treated teeth; Fracture strength; Intracanal medicament; Remaining cavity wall; Root facture.

Evaluation of bioceramics and zirconia-reinforced glass ionomer cement in repair of furcation perforations: An in vitro study.

Aim:The aim and objective of this study was to evaluate and compare the sealing ability of EndoSequence BC RRM-fast set putty, Proroot mineral trioxide aggregate (MTA), and Zirconomer in the repair of furcal perforation by measuring dye leakage under stereomicroscope.Methodology:A standard access cavity was made on forty-eight extracted mandibular and maxillary first molars followed by creating a furcal perforation in the center of the pulp chamber by using No. 4 round bur (creating a perforation of 2 mm diameter). Teeth were categorized into 4 groups containing 12 samples in each group based on material used for furcation repair. Group 1 – Endosequence BC RRM-fast set putty; Group 2 – Zirconomer; Group 3-MTA (positive control); Group 4 – negative control. All groups were covered with two layers of clear varnish except for 2 mm around the perforation region. All the teeth were immersed in 2% methylene blue dye for 48 h for dye penetration. Teeth were sectioned buccolingually using a diamond disk. The sectioned teeth were examined under stereomicroscope with ×10 magnification for dye penetration.Results:Endosequence showed less microleakage than MTA but not statistically significant. Zirconomer showed statistically significant higher microleakage.Conclusion:Endosequence and MTA showed less microleakage hence can be used as furcation repair materials. Due to higher microleakage, Zirconomer should be avoided as furcation repair material. Due to its favorable cost, ready availability, and almost similar outcome as bioceramics, MTA is considered as an alternative to Endosequence and is the gold standard in furcation repair.

Prevention of coronal discoloration induced by root canal sealer remnants using Dentin Bonding agent: An in vitro study.

Introduction:Among the various causes of tooth discoloration after root canal treatment, percolation of sealer remnants into the dentinal tubules of the pulp chamber is the most common cause.Objectives:The aim of this study is to evaluate the efficacy of dentin bonding agent (DBA) in preventing coronal discoloration caused by four different root canal sealers- MTA Fillapex, Sealapex, Zical and Z. O. B seal at different time intervals by measuring chromatic alterations using digital images analysis method.Methodology:Ninety mandibular premolars were collected and sectioned at 1 mm below the cementoenamel junction. Standard access cavity preparations of dimensions (depth-3 mm, width-0.8 mm, and length-3 mm) were prepared with a No. 245 bur through the cervical access. Following the standard irrigation protocol, specimens were then randomly divided into nine groups (four groups without DBA [1–4] +4 groups with DBA [5–8] +1 negative control [9]). In Groups 1–4, four different root canal sealers (MTA Fillapex, Sealapex, Zical, and Z.O.B seal) were applied to the walls of the pulp chamber. For Groups 5–8, the samples were etched with 37% phosphoric acid and DBA application was done before the respective root canal sealer application. The cervical access in all specimens was sealed using glass ionomer cement. Digital photographs were taken under standard lighting and environmental conditions at different time intervals: preprocedural, postprocedural, and after 1, 2, 3, and 4 months. These images were analyzed using Adobe Photoshop CS6 from which laboratory values and subsequently Delta E values were obtained.Results:Statistical analysis performed using repeated measures ANOVA and post hoc Tukey's tests show that the groups with DBA application had significantly lower mean Delta E values (P < 0.05) compared to the groups without DBA application.Conclusion:DBAs applied to the dentinal walls of the pulp chamber before obturation can effectively reduce the sealer-induced coronal discoloration.