Effect of Chitosan Irrigant and Lubricating Gel on Bond Strength of Resin Sealer to Radicular Dentin: An In Vitro Study.

BACKGROUND: The adhesive strength of sealers to dentin is influenced by various factors, and the presence of a smear layer is among the critical variables. Chitosan, known for its dentin compatibility, has previously demonstrated a reduction in dentin change and resin sealer bond strength comparable to ethylenediaminetetraacetic acid (EDTA) when used as an irrigant and final rinse. The study investigates the impact of chitosan, used as both a lubricating gel and final rinse, on the push-out bond strength of resin sealer. MATERIALS AND METHOD: Forty single-rooted premolar teeth, each with a fully formed root and a single root canal, were collected post-extraction. During canal preparation, 1 ml sodium hypochlorite (3%) was used for irrigation at every change of instrument, followed by applying specific chelating gel and final rinse for each experimental group. The groups included: Group 1 (17% EDTA chelating gel, final rinse with saline), Group 2 (17% EDTA chelating gel, final rinse with 17% EDTA solution), Group 3 (chitosan chelating gel, final rinse with saline solution), and Group 4 (chitosan chelating gel, final rinse with 0.2% chitosan solution), 10 specimens in each group. After obturation, specimens were sealed and incubated for a week at 37°C with 100% humidity. The universal testing machine was used for push-out tests, and specimens were examined using a scanning electron microscope (SEM) to identify various types of bond failure. RESULTS: Among the four groups, Group 2 exhibited the highest mean push-out bond strength (7.33 ± 0.26 MPa), followed by Group 4 (5.33 ± 0.25 MPa), Group 1 (4.61 ± 0.30 MPa), and Group 3 (2.94 ± 0.32 MPa). The variations in bond strength suggest a notable impact of the chelating agents and final rinse solutions on the resin sealer's interaction with dentin. CONCLUSION: The study concludes that the use of EDTA as both a lubricating gel and a final rinse significantly enhances push-out bond strength, outperforming chitosan in this study. Groups with saline as the final rinse (Group 1 and Group 3) exhibited the least bond strength, highlighting the importance of the final rinse in root canal therapy.

Evaluation of Immediate and Delayed Microleakage of Class V Cavities Restored with Chitosan-incorporated Composite Resins: An In Vitro Study.

AIM AND OBJECTIVE: To evaluate and compare the microleakage of unmodified microhybrid composite and 0.2% chitosan-incorporated composite in class V cavities restored immediately and after 3 months of storage in artificial saliva. MATERIALS AND METHODS: Sixty human permanent maxillary premolars were collected and standardized class V cavity prepared on the buccal surface of each tooth with dimensions: mesiodistally 3 mm, occluso cervically 2 mm, and depth of 1.5 mm and restored with microhybrid composite and chitosan-incorporated composite resins respectively and randomly divided: Group I: control-microhybrid composite (n = 30): (a) 15 teeth tested immediately (b) 15 teeth tested after 3 months. Group II-restored with chitosan + composite (n = 30): (a) 15 teeth tested immediately (b) 15 teeth tested after 3 months. Specimens were stored in artificial saliva following which a dye extraction test was carried out using a spectrophotometer. RESULTS: There was no statistically significant difference in microleakage score between the chitosan-composite group and unmodified composite group when evaluated immediately after placing the restoration. Microleakage values of the unmodified composite group increased significantly after 3 months of storage in artificial saliva and values of the chitosan-composite group did not differ significantly even after 3 months of storage. Microleakage was seen significantly less in the chitosan-composite group compared to the unmodified composite group after 3 months of storage in artificial saliva. CONCLUSION: It can be concluded that chitosan-incorporated composite seems to have improved mechanical properties and forms a more stable bond when compared with unmodified microhybrid composite in addition to being antibacterial. CLINICAL SIGNIFICANCE: Considering the advantageous properties of this material, it may be clinically useful in restoring class V cavities in patients with high caries risk. However, further in vitro and in vivo studies need to be carried out. HOW TO CITE THIS ARTICLE: Deb A, Pai V, Nadig RR. Evaluation of Immediate and Delayed Microleakage of Class V Cavities Restored with Chitosan-incorporated Composite Resins: An In Vitro Study. Int J Clin Pediatr Dent 2021;14(5):621-627.

Evaluation of Microleakage of Micro Hybrid Composite Resins versus Chitosan-Incorporated Composite Resins When Restored in Class V Cavities Using Total Etch and Self-Etch Adhesives: An In vitro Study.

AIM: To evaluate the in-vitro microleakage of traditional micro hybrid composite resin and 0.2% chitosan-incorporated composite resin when restored in Class V cavities using total etch versus self-etch adhesives after storing in artificial saliva for 24 h. MATERIALS AND METHODOLOGY: Sixty permanent maxillary premolars collected and Class V cavities were prepared on buccal surface of each tooth (dimensions: mesio-distally 3 mm, occluso cervically 2 mm, and depth of 1.5 mm) and restored with Group 1: micro hybrid (30 teeth) and Group 2: chitosan-incorporated composite (30 teeth), which was further subdivided into: (a) 15 teeth using total-etch adhesives. (b) 15 teeth using self-etch adhesives. Next dye extraction test was carried out using spectrophotometer. RESULTS: Comparison within groups: In Group 1: Self-etch demonstrated less microleakage (0.0129) compared with total etch (0.0183). The difference was statistically significant, and in Group 2: No statistically significant difference was found in mean microleakage scores after using either self-etch (0.0118) or total etch adhesives (0.0120). CONCLUSION: It can be concluded that chitosan-incorporated composite seems to have improved mechanical properties with a stable bond when used with either self-etch or total etch adhesives in addition to being antibacterial. It may be clinically useful in restoring Class V cavities in patients with high caries risk. However, further in vitro and in-vivo studies need to be carried out.

Effect of a Papain-based Chemomechanical Agent on Structure of Dentin and Bond Strength: An in vitro Study.

AIM: To evaluate the microtensile bond strength of teeth restored with packable composite after removing caries with three chemomechanical caries removal agents (Carisolv, Papacarie and Carie-care) and also to analyze its effect on chemical composition of dentin using energy-dispersive X-ray (EDX) analysis. DESIGN: A total of 40 carious molars with 1 to 1.5 mm of remaining dentin were selected and divided into four groups of 20 each. Group I (control)-bur, group II-Carisolv, group III-Papacarie, group IV-Carie-care. A total of 15 samples from each group were restored with composite; 1 mm thick sections were made and were debonded under tensile load. Remaining five samples from each group were subjected to EDX for elemental analysis of dentin surface. RESULTS: No statistically significant difference in the bond strength values and Ca/P ratio was observed between control group and three chemomechanical agents tested in the study. CONCLUSION: None of the chemomechanical agents tested in the study adversely affected the bond strength of composite resin to caries-affected dentin. Therefore, newer papain-based chemomechanical agent Carie-care can be considered as an equally effective economical alternative to commonly used agents Carisolv and Papacarie.How to cite this article: Nair S, Nadig RR, Pai VS, Gowda Y. Effect of a Papain-based Chemomechanical Agent on Structure of Dentin and Bond Strength: An in vitro Study. Int J Clin Pediatr Dent 2018;11(3):161-166.

Comparative evaluation of smear layer removal by chitosan and ethylenediaminetetraacetic acid when used as irrigant and its effect on root dentine: An in vitro atomic force microscopic and energy-dispersive X-ray analysis.

AIM: This study was undertaken to evaluate the efficacy of smear layer removal and nanostructural and chemical changes caused by chitosan and ethylenediaminetetraacetic acid (EDTA) on tooth surface using atomic force microscopic analysis and energy-dispersive X-ray (EDX) analysis. METHODOLOGY: Forty single-rooted premolars were decoronated to a standard length of 15 mm and enlarged to Protaper F3 with irrigation of 1 mL 1% NaOCl and deionized water. Specimens were then divided into 4 groups with 10 samples each and subjected to final rinse with 17% EDTA solution, 0.2% and 0.5% chitosan solution for 1 min. Samples were sectioned into 2 halves. One half of sample from each group were subjected to EDX analysis to check the calcium/phosphate (Ca/P) ratio. The second half of sample from each group subjected to atomic force microscopy (AFM) analysis to study the smear layer removal and nanostructural changes. Statistical analysis was done using ANOVA and Chi-square test. RESULTS: The AFM images showed no difference in the elimination of smear layer. The quantitative analysis using AFM showed EDTA group had significantly higher surface alteration than chitosan. EDX analysis showed that the Ca/P ratio of root dentine in EDTA group is significantly lower than chitosan group. CONCLUSION: Chitosan is an effective chelating agent with less alteration in radicular dentine.

Reinforcing Effects of Calcium Silicate-based Cement and Dual Cure Composite Resin in Simulated Immature Teeth with an Open Apex: An in vitro Study.

AIM: To evaluate the fracture resistance of simulated immature teeth with an apical plug of biodentine followed by composite resin vs total obturation with biodentine tested immediately and after 3 months of aging and also to find out the chemical composition of dentin in contact with these materials. MATERIALS AND METHODS: Extracted human maxillary central incisors with simulated immature apex with radicular dentin thickness (RDT) of 1 to 1.5 mm selected and divided into three groups of 20 each. Group I (control)-4 mm biodentine apically and thermoplasticized gutta-percha. Group II-4 mm biodentine apically and composite resin. Group III-complete obturation with biodentine. About 10 samples from each group were tested immediately and remaining 10 stored in phosphate buffered solution (PBS) and tested after 3 months for fracture resistance and chemical analysis of dentin. RESULTS: No significant difference in fracture resistance between the groups was observed when tested immediately. After 3 months of aging, only biodentine group showed a significant reduction in fracture resistance with increased Ca/P ratio of root dentine. CONCLUSION: Biodentine group has shown drastic reduction in fracture resistance after 3 months of aging, and hence, cannot be recommended as a reinforcement material in immature teeth with thin dentin walls.How to cite this article: Zhabuawala MS, Nadig RR, Pai VS, Gowda Y, Aswathanarayana RM. Reinforcing Effects of Calcium Silicate-based Cement and Dual Cure Composite Resin in Simulated Immature Teeth with an Open Apex: An in vitro Study. Int J Clin Pediatr Dent 2017;10(4):351-357.

Comparison of fracture resistance of simulated immature teeth with an open apex using Biodentine and composite resin: An in vitro study.

AIM: To evaluate the fracture resistance in simulated immature teeth that had been backfilled using composite resin and Biodentine after using Biodentine as an apical plug material immediately and after 3 months of aging. MATERIALS AND METHODS: Sixty extracted human maxillary central incisors were simulated in an immature open apex. The roots of all the specimens were then standardized to a length of 10 mm and canals were instrumented to obtain the radicular dentin thickness around 1.5 mm. All the specimens were then randomly divided into three groups of twenty teeth each. Group I (control) - 4 mm apical plug of Biodentine backfilled with thermoplasticized gutta-percha. Group II - 4 mm apical plug of Biodentine and then backfilled with ParaCore. Group III - completely filled with Biodentine. Ten samples from each group were randomly divided into two subgroups. In subgroup A: Specimens were stored for 1 week. In subgroup B: Specimens were stored in phosphate-buffered saline solution for 3 months and were subjected to universal testing machine. Statistical analysis was done using one-way analysis. RESULTS: No significant difference in fracture resistance between the groups was observed when tested immediately. After 3 months of aging, only Biodentine group showed a significant reduction in fracture resistance without significant reduction with other two groups. CONCLUSION: Biodentine group has shown a drastic reduction in fracture resistance after 3 months of aging, and hence cannot be recommended as a reinforcement material in immature teeth with thin dentin walls.

Comparison of third generation versus fourth generation electronic apex locators in detecting apical constriction: An in vivo study.

AIM: The aim of this in vivo study was to compare the accuracy of Root ZX and Raypex 5 in detecting minor diameter in human permanent single-rooted teeth. MATERIALS AND METHODS: Thirty-one patients with completely formed single-rooted permanent teeth indicated for extraction were selected for the study. Crown was flattened for stable reference point and access cavity prepared. Working length was determined with both apex locators. A 15 K file adjusted to that reading was placed in the root canal and stabilized with cement. The tooth was then extracted atraumatically. Following extraction apical 4 mm of root was shaved. The position of the minor diameter in relation to the anatomic apex was recorded for each tooth under stereomicroscope at ×10. The efficiency of two electronic apex locators to determine the minor diameter was statistically analyzed using paired sample t-test. RESULTS: The minor diameter was located within the limits of ±0.5 mm in 96.6% of the samples with the Root ZX and 93.2% of the samples with Raypex 5. The paired sample t-test showed no significant difference. CONCLUSION: On analyzing the results of our study it can be concluded that Raypex 5 was as effective as Root ZX in determining the minor diameter.

Evaluation of Gingival Microleakage in Class II Composite Restorations with Different Lining Techniques: An In Vitro Study.

Aim. To compare the microleakage in class II composite restorations without a liner/with resin modified glass ionomer and flowable composite liner. Method. Forty standardized MO cavities were prepared on human permanent mandibular molars extracted for periodontal reasons and then divided into 4 groups of ten specimens. The cavity preparations were etched, rinsed, blot dried, and light cured and Adper Single Bond 2 is applied. Group 1 is restored with Filtek P60 packable composite in 2 mm oblique increments. Group 2 is precure group where 1 mm Filtek Z350 flowable liner is applied and light cured for 20 sec. Group 3 is the same as Group 2, but the liner was cocured with packable composite. In Group 4, 1 mm RMGIC, Fuji Lining LC is applied and cured for 20 sec. All the teeth were restored as in Group 1. The specimens were coated with nail varnish leaving 1 mm around the restoration, subjected to thermocycling, basic fuchsin dye penetration, sectioned mesiodistally, and observed under a stereomicroscope. Results. The mean leakage scores of the individual study groups were Group 1 (33.40), Group 2 (7.85), Group 3 (16.40), and Group 4 (24.35). Group 1 without a liner showed maximum leakage. Flowable composite liner precured was the best.

Sub-hepatic caecum.

Malrotation of gut is an intestinal gestational disorder which not only affects the positioning of the midgut, but also its vascular supply. It usually presents with the syndrome of bouts of colic and vomiting with little distention of abdomen and diarrhea. Though midgut malrotation is a common cause of intestinal obstruction in newborn, scant attention is given to this developmental anomaly as a cause of symptoms in adults. The development of midgut portion of alimentary canal suffers a large variety of variations. The surgical importance of abdominal situation of the portions of intestine derived from the midgut loop requires little attention. Sub-hepatic anatomical location of the appendix makes it more difficult to diagnose acute appendicitis at any age, including in older adults. Failure to recognize the nature and characteristic features of these misplacements may lead to grave errors in procedure, or to injurious prolongation of the operation. Here in we found a rare abnormality of caecum, which was present in the sub hepatic region with the absence of ascending colon during routine dissection classes for undergraduate students.

Differentiation of isolated and characterized human dental pulp stem cells and stem cells from human exfoliated deciduous teeth: An in vitro study.

AIMS AND OBJECTIVES: Isolation, characterization and differentiation of dental pulp stem cells (DPSCs) and stem cells from exfoliated human deciduous teeth (SHED). METHODS: The pulp tissue was digested in collagenase and cultured in DMEM Dulbecco's Modified Eagle's Media). The stem cells were identified and isolated. Surface characterization of cells was done with flow cytometer using surface markers. An immuno cytochemistry analysis was done. Differentiation potential was analyzed using various differentiation markers. RESULTS: Flow cytometry analyses for various CD markers showed similar results for both DPSCs and SHED. The cells showed positive expression for pluripotent, ectodermal and mesodermal markers. Cells differentiated into osteoblasts and adipocytes. CONCLUSION: The study demonstrated that stem cells existed in deciduous and permanent pulp tissue. The stem cells present in pulp tissue can be isolated, cultivated and expanded in vitro. Both DPSCs and SHED show almost a similar expression pattern profile for variety of antigens tested.

Chemical analysis of dentin surfaces after Carisolv treatment.

AIMS AND OBJECTIVES: This study was done to characterize the surface chemistry after caries excavation with burs and Carisolv 2, by analyzing the relative amounts of organic and inorganic content, and also to analyze the penetration of the adhesive after etching and bonding using Micro Raman spectroscopy. MATERIALS AND METHODS: Twenty extracted molars with caries were distributed into the following groups and treated accordingly. Group 1-excavation with bur (10 teeth), and Group 2-excavation using Carisolv 2 (10 teeth). RESULTS AND CONCLUSION: Spectroscopic analysis showed that there was no significant difference in the chemical composition of the tooth between the groups after excavation (P > 0.05) either with bur or with Carisolv. The penetration of the dentin bonding resin in all samples of the Carisolv group was up to 15mum, whereas, in the bur group it was upto 10mum in few samples. Scanning Electron Microscopic analysis showed the surfaces of the Carisolv-treated dentin to be free of the smear layer, with open tubules, whereas, the dentin surfaces of the bur group showed surfaces covered with a smear layer. In the Carislov group the resin tags were found comparatively deeper than in the bur excavation group. In both the groups the integrity of the remaining dentin surfaces were maintained chemically and morphologically.