Comparative assessment of nanosized intracanal medicaments on penetration and fracture resistance of root dentin - An in vitro study

Context

The antimicrobial potential of conventional medicaments is reduced due to their limited permeability. The use of calcium hydroxide (CH) is known to reduce the root strength. Nano intracanal medicaments have the following advantages over conventional such as higher surface area and chemical reactivity, and due to its nanosize, have better penetrability, supporting its possible use as an intracanal medicament. Nano versions of CH, chitosan (CS), CS + CH, curcumin (T), and its conventional forms are used in our study.

Aim

The aim of this study was to evaluate and compare the depth of penetration of nanosized intracanal medicaments and their effect on fracture resistance of root dentin.

Materials and Methods

Eighty extracted single-rooted teeth were used after decoronation. Canals were enlarged up to size 30 (0.04° taper) using Neoendo instruments (Orikam, India). Teeth were randomly assigned to two broad groups based on the type of intracanal medicament used; Group A: control (conventional) (n = 40) and Group B: nanosized intracanal medicaments (n = 40). Each group was subdivided into four experimental groups (n = 10), Group A1: CH, Group A2: CS, Group A3: curcumin (T), Group A4: CS + CH, Group B1: nano calcium hydroxide (NCH), Group B2: nano CS (NCS), Group B3: nano curcumin (NT), and Group B4: NCS + nano calcium hydroxide (NCS + NCH). All the specimens were stored in a humidor at 37°C for 4 weeks. Out of 10 specimens from each group, five specimens were used for evaluating the depth of penetration using a confocal laser scanning electron microscope, and the remaining five specimens were used for evaluating fracture resistance in a universal testing machine at the end of 4 weeks. Data were analyzed using one-way ANOVA and intergroup comparison using Tukey's post hoc multiple comparison test.

Results

The highest fracture resistance was seen with NCS and the maximum depth of penetration with nano calcium hydroxide (NCH).

Conclusion

The fracture resistance and depth of penetration at a 4-week interval were higher in nano forms compared to their micro-sized counterparts with all groups. The coronal section presented the highest depth of penetration of intracanal medicaments followed by the middle and least in the apical section of root dentin with all groups.

Effect of silver diamine fluoride, potassium iodide, and glutathione on micro-shear bond strength of glass ionomer cement to caries affected dentine

BACKGROUND

Silver diamine fluoride (SDF, 38%) is an efficient topical fluoride used to arrest dental caries though it causes black staining of both teeth and restoration. The application of potassium iodide (KI) after SDF reduces the stain, but the color change is only temporary. An alternative method suggested is by mixing glutathione (GSH) with SDF, which preserves the silver ions of SDF within the solution. Hence, the purpose of this in vitro study was to evaluate the microshear bond strength (μSBS) of glass ionomer cement (GIC) to caries affected dentin (CAD) pretreated with SDF/KI/GSH.

MATERIALS AND METHODS

Thirty dentine slices of 2 mm thickness from human permanent upper premolars were demineralized using pH cycling method to mimic CAD. They were allocated to three groups of 10 each and treated with SDF, SDF-KI (SDF followed by KI), SDF + GSH (SDF mixed with GSH), respectively. Specimens were bonded with GICs. The μSBS was assessed using a universal testing machine and the data obtained were analyzed using one-way ANOVA and Tukey's post hoc test.

RESULTS

The μSBS (mean ± standard deviation) values for groups SDF, SDF-KI, and SDF + GSH were 4.81 ± 2.026, 5.78 ± 1.809, 8.18 ± 2.828 megapascal respectively. Group 3 showed significantly better bond strength compared to groups 1 and 2. In group 2, the addition of KI showed better bond strength when compared to group 1, but the difference was not statistically significant.

CONCLUSION

Pretreatment of teeth with GSH along with SDF application showed significantly better bond strength of GIC to CAD compared to SDF and SDF-KI.

The effect of bulk-fill composites: Activa and Smart Dentin Replacement on cuspal deflection in endodontically treated teeth with different access cavity designs

Aim:

The aim was to evaluate the effect of bulk-fill composites – Activa and Smart Dentin Replacement (SDR) on cuspal deflection in endodontically treated teeth with different access cavity designs.

Materials and Methods:

Forty-two maxillary first premolar teeth were randomly divided into three experimental groups based on different access designs as Group I – conservative endodontic cavities (CECs), Group II – traditional endodontic cavities, and Group III – CECs with diverging walls and two subgroups, based on the different access cavity restorations subgroup A-Activa and subgroup B-SDR with n = 7 per group. Root canal treatment was completed under the dental operating microscope. Cuspal deflection was assessed by measuring the distance between the glass beads using an optical microscope and micrometer immediately after a Root canal treatment and final measurements after access restorations. Data were statistically analyzed and tabulated.

Results:

Results showed that the access cavity restored with Activa showed the highest cuspal deflection than SDR in all the groups (P < 0.05). Conservative access designs showed the least cuspal deflection among other groups.

Conclusion:

CEC designs showed lesser cuspal deflection than traditional endodontic cavity designs. SDR can be considered as a choice of material for access restorations.

Evaluation of Free Available Chlorine of Sodium Hypochlorite When Admixed with 0.2% Chitosan: A Preliminary Study

AIM AND OBJECTIVE

The aim of the study was to evaluate the changes in free available chlorine (FAC) when 6% sodium hypochlorite (NaOCl) is admixed with irrigants 17% ethylenediaminetetraacetic acid (EDTA), 2% chlorhexidine (CHX), and 0.2% chitosan in varying proportions of 90:10, 80:20, and 50:50.

MATERIALS AND METHODS

The 25 mL aliquots of 6% NaOCl were admixed in varying proportions of 90:10, 80:20, and 50:50 with secondary irrigation solutions: (a) 17% EDTA, (b) 2% CHX, (c) 0.2% chitosan. Iodometric titration was done to evaluate the change in FAC.

STATISTICAL ANALYSIS USED

Kruskal-Wallis and Mann-Whitney tests.

RESULTS

On titration, the mean FAC value of NaOCl at baseline was 1.99 g%. On mixing NaOCl with EDTA, the FAC decreased in all the three proportions and the values were 0.17 g%, 0.17 g%, and 0.06 g% at 90:10, 80:20, and 50:50 ratios, respectively. pH obtained was 9.55 at 50:50 ratio. On mixing NaOCl with CHX, FAC reduced and the values were 1.84 g%, 1.72 g%, and 0.27 g% at 90:10, 80:20, and 50:50 ratios, respectively. pH obtained was 10.87 at 50:50 ratio. On mixing NaOCl and chitosan, the FAC remained unaltered in all the three proportions and the values were 1.64 g%, 1.51 g%, and 1.63 g% at 90:10, 80:20, and 50:50 ratios, respectively. pH obtained was 11 at 50:50 ratio.

CONCLUSION

Combination of NaOCl and chitosan did not lead to a reduction in FAC and the pH of the solution remained unaltered, suggesting that tissue-dissolving property of NaOCl might be preserved.

CLINICAL SIGNIFICANCE

The combination of chitosan with NaOCl is advantageous in two ways. Firstly, FAC remained unaltered and the pH of the solution was also maintained at 11.05 indicating that the tissue-dissolving property of NaOCl prevailed. Secondly, chitosan is known for its chelating property and is effective in smear layer removal. With further in vivo and in vitro studies, a combination of chitosan and NaOCl can be proposed as a novel irrigant.

Is odontogenic keratocyst an endodontic enigma? A rare case report of management of odontogenic keratocyst in anterior mandible

Odontogenic keratocyst (OKC), a rare, locally aggressive developmental cyst, is found incidentally on dental radiographs, most commonly in the posterior mandible. When it occurs in the periapical region in association with nonresponding teeth to pulp sensibility tests, it is often misdiagnosed as other endodontic lesions such as radicular cyst, lateral periodontal cyst and dentigerous cyst. This case report describes the rare occurrence of OKC in the anterior mandibular region managed successfully with endodontic treatment and re-interventional surgery in a conservative approach. This case report also emphasizes on the importance of histopathological examination of the surgically excised tissue specimens as the clinical, radiographic and histopathological correlations are essential for successful treatment.

Comparative evaluation of fracture toughness and marginal adaptation of two restorative materials in nonendodontically and endodontically treated teeth: An in vitro study

Objective

To evaluate and compare the fracture resistance and marginal adaptation of Zirconomer and bulk fill posterior restorative material (Surefil SDR) in nonendodontically and endodontically treated teeth.

Materials and Methods

The sample consisted of 52 caries-free extracted human premolars which were individually mounted in polyvinyl chloride (PVC) ring filled with acrylic resin up to 1.0 mm below the cementoenamel junction. The teeth were then divided into four groups according to the restorative material used as group I: Zirconomer + Operative only, Group II: Zirconomer + Endodontic treatment, Group III: SDR + Operative, and Group IV: SDR + Endodontic treatment. Fracture strength was tested using a universal testing machine and was expressed in Newtons. The marginal gap was measured at its maximum using a scanning electron microscope and expressed in micrometers. One-way analysis of variance followed by Tukey's post hoc test was used to compare the mean fracture resistance (N) and marginal adaptation (μm) between the four groups. Statistical significance was determined at α = 0.05.

Results

Group 3 exhibited significantly highest mean fracture resistance than Group 1 (P < 0.001), Group 2 (P < 0.001), and Group 4 (P < 0.001). Group 4 had significantly higher mean fracture resistance than Group 1 (P = 0.008) and Group 2 (P < 0.001). Group 1 exhibited significantly highest mean marginal gap than Group 3 (P < 0.001) and Group 4 (P < 0.001). Group 2 had a significantly higher mean marginal gap than Group 3 (P < 0.001) and Group 4 (P < 0.001).

Conclusion

The fracture resistance and marginal adaptation of Zirconomer are significantly lower than Surefil SDR in both nonendodontically and endodontically treated teeth.

An analysis of cyclic fatigue resistance of reciprocating instruments in different canal curvatures after immersion in sodium hypochlorite and autoclaving: An in vitro study

Aim

The aim of this study is to assess the effect of sodium hypochlorite and sterilization on the cyclic fatigue resistance of two reciprocating nickel-titanium files using a rotary and a reciprocating motor.

Materials and Methods

Totally, 160 Reciproc and Wave One files were tested. The eighty files of the same brand were assigned into four groups (n = 20). These four groups were further divided into two subgroups, 1a and 1b, 2a and 2b, 3a and 3b, 4a and 4b consisting of ten files in each group. 2.5% NaOCl for 5 min, 2.5% NaOCl for 5 min + 1 cycle of autoclave sterilization, 2.5% NaOCl for 5 min + 5 cycles of autoclave sterilization, no sterilization (control). Groups 1a, 2a, 3a, and 4a were subjected to 30° and Groups 1b, 2b, 3b, and 4b were subjected to 60° canal curvature.

Results

Intergroup comparison reveals that there is an increase in cyclic fatigue resistance from the first cycle to the fifth cycle of autoclave which is statistically significant.

Conclusion

Reciproc and Wave One showed reduced cyclic fatigue resistance on immersion in NaOCl for 5 min. Multiple autoclaving cycles significantly increased the cyclic fatigue resistance of Reciproc file system in both the curvatures. There was a decrease in cyclic fatigue resistance for Wave One after multiple autoclaving at 60° curvature which was statistically significant.

Effect of dentin on the antimicrobial efficacy of 3% sodium hypochlorite, 2% chlorhexidine, 17% ethylenediaminetetraacetic acid, and 18% etidronic acid on Candida albicans: An in vitro study

AIM

The aim of this study was to evaluate the effect of dentin on the antimicrobial efficacy of 3% sodium hypochlorite, 2% chlorhexidine, 17% EDTA and 18% etidronic acid against C. albicans.

METHODOLOGY

Dentin powder was prepared from mandibular first premolar using electrical grinder and sterilized. 3% NaOCl, 2%CHX, 17% EDTA and 18% etidronic acid were tested against C. albicans in the presence and absence of dentin, in eppendorf tubes. Group 1 (presence of dentin):- 100ul dentin powder + 100ul C. albicans suspension + 100ul irrigating solution. Group 2 (absence of dentin):- 100ul C. albicans suspension+ 100ul irrigating solution.

CONTROL GROUP

- 100ul C. albicans suspension.+ 100ul sterile saline Suspension was thoroughly mixed, submitted for serial dilution upto10-5 after 1 min and colony forming units were counted.

RESULTS

In group 2 (without dentin powder), 3% NaOCl and 2% CHX showed the lowest bacterial count compared to group 1 (with dentin powder). Dentin had a significant inhibitory effect on 3% NaOCl (P < 0.001) and 2% CHX (P<0.001). 17% EDTA showed lowest bacterial count in group 1 (with dentin powder) compared to group 2 (without dentin powder). 18% Etidronic acid showed similar bacterial counts in the both the groups. No reduction was observed in the control group.

CONCLUSION

NaOCl & EDTA showed measurable antimicrobial effect even in the presence of dentin which can be promising in the reduction of C. albicans in root canal therapy.

Study of the anesthetic efficacy of inferior alveolar nerve block using articaine in irreversible pulpitis

AIM

The purpose of this study was to determine the anesthetic efficacy of inferior alveolar nerve block (IANB) using 4% articaine and 2% lidocaine supplemented with buccal infiltration.

MATERIALS AND METHODS

Forty five patients, diagnosed with irreversible pulpitis of a mandibular posterior tooth were included in the study. The first group of 15 patients received 2% lidocaine with 1:200000 epinephrine, the second group 2% lidocaine with 1: 80,000 epinephrine and the third group of 15 subjects received 4% articaine with 1:100000 epinephrine. During the access cavity preparation those patients who complained of pain received an additional buccal infiltration. The percentage of subjects who got profound anesthesia and failure to achieve anesthesia were calculated and tabulated using a visual analog scale.

RESULTS

The results revealed that 87% of subjects who received 4% Articaine with 1:100,000 epinephrine got satisfactory anesthesia with inferior alveolar nerve block alone. Only 2 (13%) subjects received an additional buccal infiltration and none of the patients failed to obtain complete anesthesia with articaine. In comparison only 40% of subjects got complete anesthesia with 2% lidocaine with 1:200000 and 60% with 2% lidocaine with 1:80,000.

CONCLUSION

It can be concluded that 4% articaine can be used effectively for obtaining profound anesthesia for endodontic procedures in patients with irreversible pulpitis.

The prevalence of bilateral three-rooted mandibular first molar in Indian population

INTRODUCTION

The purpose of the present study was to evaluate the prevalence of bilateral three-rooted mandibular first and second molars in Indian population.

MATERIALS AND METHODS

A total of 215 patients were screened bilaterally for mandibular first and second molar and 430 samples of periapical radiographs were obtained. The gender, symmetry, and prevalence of three-rooted mandibular first and second molars were recorded. The correlation between left and right side occurrences and distribution were recorded and analysed using Z-test.

RESULTS

The results showed that 33 teeth had three-rooted mandibular first molars, 16 male and 17 female (P=0.442). Overall, 21 teeth of right jaw and 12 teeth of left jaw (P=0.103) showed presence of an extra-root. The prevalence of three-rooted mandibular first molars was 7.67% and second molar was 0.23%. The bilateral frequency distribution was 3.72% for the first molar. There was no statistically significant difference between right side and left side mandibular molars. Also, gender did not show a significant relationship with this variant.

CONCLUSION

The endodontic treatments of first mandibular molars require a careful clinical approach in Indian population as a high racial prevalence of 7.67% three-rooted molars was found. However, in the same population, 0.23% mandibular second molars had three roots.

The reinforcement effect of polyethylene fibre and composite impregnated glass fibre on fracture resistance of endodontically treated teeth: An in vitro study

Aim:

The aim of this study was to evaluate the fracture resistance of endodontically treated maxillary premolars with wide mesio-occluso-distal (MOD) cavities restored with either composite resin, or composite resin reinforced with different types of fibres.

Materials and Methods:

Fifty human maxillary premolars were selected. Five intact teeth served as positive controls. Endodontic therapy was carried out in the remaining forty-five teeth. Standardized MOD cavities were prepared in all the teeth. The teeth were restored with a nanocomposite using an incremental technique. These forty five teeth were randomly divided into three experimental groups (Group A, B and C) (n = 15). The teeth in Group A did not undergo any further procedures. The teeth in Group B and C were reinforced with composite impregnated glass fibre and polyethylene fibre, respectively. Fracture resistance was measured in Newtons (N).

Results:

The positive controls showed the highest mean fracture resistance (811.90 N), followed by Group B (600.49N), Group A (516.96N) and Group C (514.64N), respectively. One Way analysis of variance (ANOVA) test revealed a statistically significant difference between all the groups (P = 0.001). Post-hoc Tukey test revealed a moderately significant difference (P = 0.034) between Control and Group B, and a strongly significant difference between Control and Group A (P = 0.002), and Control and Group C (P = 0.001).

Conclusions:

Endodontic therapy and MOD cavity preparation significantly reduced the fracture resistance of endodontically treated maxillary premolars (P = 0.001). No statistically significant difference was found between the experimental groups (Group A, B and C) (P > 0.1). However, the fracture resistance of the composite impregnated glass fibre reinforced group was much higher than the others.

An evaluation of antibacterial efficacy of 3% sodium hypochlorite, high-frequency alternating current and 2% chlorhexidine on Enterococcus faecalis: An in vitro study

AIM

The purpose of this study was to evaluate the antibacterial efficacy of 3% sodium hypochlorite (NaOCl), high-frequency alternating current (HFAC) (Endox Endodontic System), 2% chlorhexidine (CHX) in elimination of Enterococcus faecalis from experimentally infected root canals, in vitro.

MATERIALS AND METHODS

Eighty extracted, single rooted permanent upper anterior teeth were instrumented up to size 50, teeth were sterilized and inoculated with E. faecalis, subcultured in BHI broth which had its optical density adjusted to approximately 1.5Χ10(8) colony forming units (CFUs) ml(-1) by comparing its turbidity to a McFarland 0.5 BaSO(4) standard solution. After incubation for 24 h, the contaminated root canals were divided into four groups and subjected to action of NaOCl 3%, CHX 2%, and HFAC with physiological saline as a positive control. Sterile paper points were selected to take the sample of the bacteria and transferred to tubes containing 5ml of BHI broth and then incubated for 24 and 48 h, followed by agar plating of the resultant broth turbidity on Enterococcus confirmatory agar.

RESULTS

Data obtained were analyzed statistically for differences using chi-squared test, comparing different groups, with a significance level established at P<0.05 and 3% NaOCl showed no growth postoperatively, CHX and HFAC showed reduction of postoperative growth compared to physiological saline and, were statistically significant (P<0.05).

CONCLUSION

In the present study, sodium hypochlorite, CHX, HFAC all were significantly effective in eliminating E. faecalis and sodium hypochlorite showed the maximum anti-bacterial activity against E. faecalis.