Evaluation of marginal sealing ability of self-adhesive flowable composite resin in Class II composite restoration: An in vitro study

Aim:

The aim of this study is to evaluate the marginal sealing ability of self-adhesive flowable composite resin when used as a liner in Class II composite restoration with and without aging.

Materials and Methods:

A total of 120 standardized Class II tooth preparations with gingival margins 1 mm coronal and apical to cementenamel junction (CEJ) were prepared on 60 extracted permanent mandibular molars and were randomly divided into eight equal Groups: Group 1: cavities coronal to CEJ and restored with Dyad flow liner + Herculite ultra, Group 2: same as Group 1 but cavities margins apical to CEJ, Group 5: cavities coronal to CEJ and restored with only Herculite ultra, and Group 6: same as Group 5 but cavities apical to CEJ. Groups 3,4,7,8 were similar to Groups 1,2,5,6, respectively, but were aged for 6 months. After thermocycling, microleakage testing was done using 0.5% basic fuchsin dye.

Result:

At cervical level, Group 5 exhibited statistically lower (P = 0.006) microleakage than Group 6, and Group 1 showed lesser microleakage than Group 5 (P = 0.162). Group 2 exhibited significantly less microleakage than Group 6 (P = 0.002). Increased microleakage was observed in aging Groups; however, the difference with nonaging Groups was not statistically significant (P > 0.005).

Conclusion:

Margins of the cavity in cementum can be better sealed by placing self-adhesive liner and is not affected by aging.

Four cuspal maxillary second premolar with single root and three root canals: Case report

Traditional configuration of maxillary second premolars has been described to have two cusps, one root and one or two root canals. The endodontic literature reports considerable anatomic aberrations in the root canal morphology of maxillary second premolar but the literature available on the variation in cuspal anatomy and its relationship to the root canal anatomy is sparse. The purpose of this clinical report was to describe the root and root canal configuration of a maxillary second premolar with four cusps.

Effect of methods of evaluation on sealing ability of mineral trioxide aggregate apical plug

Aim:

The purpose of the study was to evaluate and compare the sealing ability of mineral trioxide aggregate (MTA) with three different methods.

Materials and Methods:

Forty single canal teeth were decoronated, and root canals were enlarged to simulate immature apex. The samples were randomly divided into Group M_D = MTA-angelus mixed with distilled water and Group M_C = MTA-angelus mixed with 2% chlorhexidine, and apical seal was recorded with glucose penetration method, fluid filtration method, and dye penetration methods and compared.

Results:

The three methods of evaluation resulted differently. The glucose penetration method showed that M_D sealed better than M_C, but difference was statistically insignificant (P > 0.05). The fluid filtration method resulted that Group M_C was statistically insignificant superior to Group M_D (P > 0.05). The dye penetration method showed that Group M_C sealed statistically better than Group M_D.

Conclusion:

No correlation was found among the results obtained with the three methods of evaluation. Addition of chlorhexidine enhanced the sealing ability of MTA according to the fluid filtration test and dye leakage while according to the glucose penetration test, chlorhexidine did not enhance the sealing ability of MTA. This study showed that relying on the results of apical sealing by only method can be misleading.

Effect of phytic acid, ethylenediaminetetraacetic acid, and chitosan solutions on microhardness of the human radicular dentin

AIM

The purpose of this study was to evaluate the effect of phytic acid, ethylenediaminetetraacetic acid (EDTA), and chitosan solutions on the microhardness of human radicular dentin.

MATERIALS AND METHODS

Thirty dentin specimens were randomly divided into three groups of 10 specimens each according to the irrigant used: G1 - 1% phytic acid, G2 - 17% EDTA, and G3 - 0.2% chitosan. A standardized volume of each chelating solution was used for 3 min. Dentin microhardness was measured before and after application at the cervical, middle, and apical levels with a Vickers indenter under a 200-g load and a 10-s dwell time. The results were analyzed using one-way analysis of variance (ANOVA) and Student's t test.

RESULTS

Microhardness of the radicular dentin varied at the cervical, middle, and apical levels. EDTA had the greatest overall effect, causing a sharp percentage reduction in dentin microhardness with a significant difference from phytic acid and chitosan (P = 0.002). However, phytic acid and chitosan differed insignificantly from each other (P = 0.887).

CONCLUSION

All tested chelating solutions reduced microhardness of the radicular dentin layer at all the levels. However, reduction was least at the apical level. EDTA caused more reduction in dentin microhardness than chitosan while phytic acid reduced the least.

An in vitro comparative evaluation of different intraorifice barriers on the fracture resistance of endodontically treated roots obturated with gutta-percha

AIM

To compare and evaluate the root reinforcement potential of four different intraorifice barriers: Mineral trioxide aggregate (MTA), resin-modified glass ionomer cement (RMGIC), fiber-reinforced composite (FRC), and nanohybrid composite (NC).

MATERIALS AND METHODS

Seventy-five mandibular premolars were decoronated to a standardized length, and prepared and obturated with gutta-percha and AH Plus sealer. Except for control specimens, the coronal 3-mm gutta-percha was removed and filled with different materials. The specimens (75) were divided into five groups (n = 15) on the basis of the intraorifice barrier material used. Group 1: MTA, Group 2: RMGIC, Group 3: FRC, Group 4: NC, Group 5: no barrier (control). Fracture resistance of the specimens was tested.

RESULTS

Fracture resistance of roots was significantly affected by the type of intraorifice barrier used and the following pattern was observed: RMGIC > FRC > NC > MTA.

CONCLUSION

Intraorifice barriers can be regarded as a viable choice to reduce the occurrence of postendodontic root fractures. Among the four tested materials, RMGIC showed the maximum reinforcement.

Evaluation of effect of addition of 2% chlorhexidine on the sealing ability of Biodentine: An in vitro study

Aim:

To evaluate the effect of the addition of 2% chlorhexidine on the sealing ability of Biodentine.

Materials and Methods:

Forty-six extracted human premolar teeth with single canal and apical foramen were selected, cleaned, and decoronated to standardize the length of 17 mm. Canals were prepared using ProTaper rotary files till size F4. The samples were divided into 2 experimental groups of 20 samples each on the basis of absence/presence of 2% chlorhexidine in liquid: Group B_M = Biodentine mixed with the provided liquid, Group B_C = Biodentine mixed with 2% chlorhexidine in provided liquid. Three samples, each were assigned to control groups: Group B_P (positive control) = No root end filling was placed, Group B_N (negative control) = Root ends were filled as in Group B_M, and entire external surface was coated with sticky wax. The samples were then evaluated for the apical sealing using fluid filtration method.

Results:

Results were analyzed using Student's t-test (P ≤ 0.05). Group B_C showed the better sealing ability (3.06) as compared to Group B_M (3.85). However, the difference was statistically insignificant (P > 0.05).

Conclusion:

Addition of 2% chlorhexidine to the liquid enhanced the sealing ability of Biodentine.

Effect of technique of sealer agitation on percentage and depth of MTA Fillapex sealer penetration: A comparative in-vitro study

Aim:

To compare the effect of three root canal sealer activation techniques on percentage and depth of sealer penetration of MTA Fillapex and AH Plus sealers.

Materials and Methods:

Sixty teeth prepared till F5 ProTaper size were divided into three equal groups on the basis of sealer activation technique (G1: Ultrasonics, G2: Lentulo spiral, and G3: Counter-clockwise rotary motion). Each group was further divided into two equal subgroups on the basis of type of sealer used: AH Plus (Denstply, Konstanz, Germany) or MTA Fillapex (Angelus, Londrina, PR, Brazil) and obturated with gutta-percha. Horizontal sections at 3 and 6 mm from the apex were obtained and the percentage and depth of penetration of sealers into dentinal tubules were measured using confocal laser scanning microscopy (CLSM). Statistical analysis was performed utilizing Kruskal-Wallis and Mann-Whitney U tests with a significance level of 5%.

Results:

G1 showed significantly (P < 0.001) high percentage and depth of sealer penetration than G2 and G3 while the difference was insignificant (P > 0.05) between G2 and G3.

Conclusion:

Percentage and depth of sealer penetration are influenced by the type of sealer used sealer activation technique and by the root canal level. Ultrasonic method of sealer activation and MTA Fillapex showed the best results.

Multiple idiopathic external apical root resorption: A rare case report

Multiple idiopathic external apical root resorption (MIEARR) is a relatively rare condition affecting multiple teeth in a dentition. As the condition is nonsymptomatic, a case is usually detected as an incidental radiographic finding. However, it may cause pain and mobility in severe cases. It is sometimes self-limiting or sometimes may progress to tooth loss. This paper presents a case of external apical root resorption involving multiple teeth in which etiology was not identified, so idiopathic root resorption was considered as a diagnosis of exclusion.

Comparative evaluation of microleakage in Class II restorations using open vs. closed centripetal build-up techniques with different lining materials

Background:

Evaluation of microleakage is important for assessing the success of new restorative materials and methods.

Aim and Objectives:

Comparative evaluation of microleakage in Class II restorations using open vs. closed centripetal build-up techniques with different lining materials.

Materials and Methods:

Standardized mesi-occlusal (MO) and distoocclusal (DO) Class II tooth preparations were preparedon 53 molars and samples were randomly divided into six experimental groups and one control group for restorations. Group 1: Open-Sandwich technique (OST) with flowable composite at the gingival seat. Group 2: OST with resin-modified glass ionomer cement (RMGIC) at the gingival seat. Group 3: Closed-Sandwich technique (CST) with flowable composite at the pulpal floor and axial wall. Group 4: CST with RMGIC at the pulpal floor and axial wall. Group 5: OST with flowable composite at the pulpal floor, axial wall, and gingival seat. Group 6: OST with RMGIC at the pulpal floor, axial wall, and gingival seat. Group 7: Control — no lining material, centripetal technique only. After restorations and thermocycling, apices were sealed and samples were immersed in 0.5% basic fuchsin dye. Sectioning was followed by stereomicroscopic evaluation.

Results:

Results were analyzed using Post Hoc Bonferroni test (statistics is not a form of tabulation). Cervical scores of control were more than the exprimental groups (P < 0.05). Less microleakage was observed in CST than OST in all experimental groups (P < 0.05). However, insignificant differences were observed among occlusal scores of different groups (P > 0.05).

Conclusion:

Class II composite restorations with centripetal build-up alone or when placed with CST reduces the cervical microleakage when compared to OST.

Effect of addition of 2% chlorhexidine or 10% doxycycline on antimicrobial activity of biodentine

Aim:

The purpose of this in vitro study was to determine whether the addition of 2% chlorhexidine gluconate or 10% doxycycline would enhance the antimicrobial activity of Biodentine against Staphylococcus aureus (ATCC-25923), Enterococcus faecalis (ATCC-29212), Candida albicans (ATCC-90028), and Streptococcus mutans (MTCC-497).

Materials and Methods:

Three wells of 4 mm diameter and 4 mm depth on each plate were prepared on the agar medium with standardized suspensions of each microorganism. Biodentine powder mixed with 2% chlorhexidine (0.06 g) or 10% doxycycline (0.30 g) in its liquid or liquid alone was placed to fill each well. Plates were incubated at 37°C as required for microbial growth. A blinded, independent observer measured zones of inhibition. The data were analyzed using independent “t” test to compare the differences among the three cement preparations for different micro-organisms.

Results:

All Biodentine samples inhibited microbial growth. The highest mean diameters of zone of inhibition for all the micro-organisms were found around Biodentine/chlorhexidine (13.417) followed by Biodentine alone (12.236) and Biodentine/doxycycline (11.25).

Conclusion:

In conclusion, adding 2% chlorhexidine gluconate in liquid of Biodentine enhanced the antimicrobial activity of Biodentine against all the tested micro-organisms except Candida albicans, while addition of 10% doxycycline decreased the antimicrobial activity of Biodentine. The differences were significant statistically (P < 0.05).

Confocal laser scanning microscopic investigation of ultrasonic, sonic, and rotary sealer placement techniques

Background:

Sealers are used to attain an impervious seal between the core material and root canal walls.

Aim:

To compare the depth and percentage of sealer penetration with three different placement techniques using confocal laser scanning microscopy as the evaluative tool.

Materials and Methods:

Root canals of 30 single-rooted teeth were prepared to a size of F3 and AH plus sealer with Rhodamine B was applied with Ultlrasonic file (Gr-1), lentulospiral (Gr-2), and Endoactivator (Gr-3). Canals were obturated with gutta-percha. The roots were sectioned at the 3 and 6-mm levels from the apical foramen and were examined on a confocal microscope.

Results:

A statistical significant differences among Gr-1, Gr-2, and Gr-3 were found at the 3 and 6-mm level (P < 0.05; ANOVA-Tukey tests) for the depth and percentage of sealer penetration except for Gr-1 and Gr-2 at 3-mm level. Gr-1 showed maximum mean depth of penetration (810 μm) and maximum mean percentage of sealer penetration (64.5) while Gr-3 showed minimum mean depth of penetration (112.7 μm) and minimum mean percentage of sealer penetration (26.7).

Conclusion:

Depth and percentage of penetration of sealer is influenced by the type of placement technique and by the root canal level with penetration decreasing apically.

An in vivo comparative evaluation to determine the accuracy of working length between radiographic and electronic apex locators

BACKGROUND

An in vivo comparative evaluation to determine the accuracy of working length between radiographic and electronic apex locators.

AIM

The study was aimed at evaluating the accuracy of electronic apex locator, to determine the working length of root canal, and to compare it with the radiographic method of working length determination.

MATERIALS AND METHODS

A total of 20 teeth selected for the study had to go for extraction because of periodontal or orthodontic reasons. Access cavity was prepared and the clinical estimated working length (CEWL) was determined with 10-25 no. K-file. A radiograph was then taken for determining the radiographic estimated working length (REWL). For electronic measurement of root canal, a 10 no. K-file was advanced toward the apex until it reached a 0.5 mm short of apex as shown by the apex locator. After fixing the file with a light cured composite, the tooth was extracted, the tooth surface was then longitudinally grounded using straight fissure diamond bur until the root canal and the tip of the file were visible. The distance of file from the minor constriction was measured with help of stereomicroscope.

STATISTICAL ANALYSIS

The chi-square test was used for statistical analysis for this study.

RESULTS

The chi-square test where χ² = 21.034 with P = 0.000 indicated that a significant difference exists among the groups. The electronic method showed highest number of cases with the working length at the minor constrictor.

CONCLUSION

The electronic method for determining the working length of root canal was found to be more accurate than the radiographic method.

Relationship between sealing ability of Activ GP and Gutta Flow and methods of calcium hydroxide removal

Aim:

To evaluate the effect of method of calcium hydroxide intracanal dressing removal, on sealing ability of Gutta Flow and Activ GP.

Materials and Methods:

Seventy extracted mandibular premolars were sectioned at CEJ and canals were prepared with profile 4% rotary file till #40. Canals were filled with calcium hydroxide, coronally sealed with Cavit G and stored at 37°C. After 7 days, samples were divided on the basis of calcium hydroxide removal method (Master apical file, Navi Tip FX, and F File) and obturating material (Activ GP and Gutta Flow). Three coats of nail polish were applied except 2 mm around apical foramen and samples were immersed in India ink dye, sectioned, and observed under stereomicroscope for microleakage.

Results:

The results were statistically analyzed with one way ANOVA-F with Tukey HSD test with the null hypothesis set as 5%.

Conclusions:

The seal of the canal system was adversely impacted by residual calcium hydroxide when Activ GP and Gutta Flow were used as obturating material and the sealing ability of Activ GP and Gutta Flow was better when MAF was used for removal of calcium hydroxide than F file or Navi tip FX.

Effect of occlusal restoration on stresses around class V restoration interface: a finite-element study

BACKGROUND

Causes of failures in class V restorations have always been controversial until now, since the biomechanical aspects of these restorations have been understood.

AIMS AND OBJECTIVE

This study was aimed to verify the hypothesis that eccentric forces are the cause of cuspal flexure, which lead to excessive stresses at the periphery of a class V restoration, further it identifies the amount of the stress and the flexure increase in the presence of an occlusal restoration using different restorative materials to restore (both cervical and occlusal) along with their comparison with respect to amount of stresses around the cervical restorations.

MATERIALS AND METHODS

The study was done by modeling a mandibular first premolar which was sectioned bucco-lingually, in the NISA, EMRC II finite element software. A 100N eccentric load was applied on the tooth structure and stresses were observed at the peripheries of the class V restoration when it was restored with composite and with glass ionomer cement. The stresses were further analyzed in the presence of occlusal restorations with different materials and configurations.

RESULTS

It was seen that the stresses at the gingival wall interface in case of class V glass ionomer cement was more than that for composite. In the presence of an occlusal amalgam restoration, the cuspal flexure was more than that of occlusal composite and the stresses at the class V peripheries were also statistically significant.

CONCLUSION

It was suggested that lower modulus composites can flex with the tooth structure decreasing the bond failure and that the stresses are much lesser when there is absence of an occlusal restoration. Occlusal composite restorations reinforce the tooth structure and reduce the cuspal flexure as compared to silver amalgam.

Effect of cavity varnish and intermediate restorative material on coronal microleakage in endodontically treated tooth

AIM

Evaluation of microleakage in endodontically treated teeth that have been coronally sealed with eugenol and noneugenol containing zinc oxide cement, with and without the use of cavity varnish.

MATERIALS AND METHODS

The crowns of single rooted teeth were removed at the cementoenamel junction (CEJ) and the root canals were prepared and obturated with gutta-percha points and zinc oxide eugenol (ZOE) sealer using lateral condensation technique. The samples were randomly divided into four groups-group 1, coronal seal was obtained with ZOE cement; in group 2, three coats of cavity varnish followed with coronal seal of ZOE cement; in group 3, Litark a (noneugenol cement) was placed in the prepared cavity as in group 1; and in group 4, cavity varnish and Litark were placed instead of ZOE as in group 2. The specimens were immersed in 2% methylene blue dye and examined under traveling microscope for evidence of dye penetration of the material.

STATISTICAL ANALYSIS

In this study, Kruskal-Wallis test, Mann-Whitney U, and Wilcoxon W tests were used.

RESULTS

Kruskal-Wallis test with P=0.000 indicated that a significant difference exists between the four groups. Mann-Whitney U test and Wilcoxon W test showed a significant difference at 0.05 levels as follows: group 1 with group 3 and 4, group 2 with group 3 and 4, and group 3 with group 4. There was no significant difference at 0.05 levels between group 1 and group 2.

CONCLUSION

Group 4 showed significant less amount of dye penetration as compared with other groups.

Effect of sealers on fracture resistance of endodontically treated teeth with and without smear layer removal: An in vitro study

Aim:

The present study involved the in vitro comparison of root reinforcing abilities of two sealers, i.e., Ketac-Endo and Acroseal, in endodontically treated teeth in the presence and absence of smear layer.

Materials and Methods:

Fifty teeth were taken and sectioned at the cementoenamel junction. The teeth with faults were discarded and a total of 36 teeth were used for study. The samples were biomechanically prepared using step-back technique. In 10 teeth, the smear layer was preserved using sodium hypochlorite. Smear layers were removed from 10 teeth using 17% EDTA, and in another 10 samples, the smear layers were eliminated using 17% EGTA. The remaining samples served as controls. Samples were obturated with sealers using the lateral condensation technique. Ketac-Endo (3M) is a glass ionomer based root canal sealer, and Acroseal (Septodont) sealers were used. The teeth were then tested by using an Instron testing machine.

Results:

Ketac-Endo shows higher fracture resistance values in comparison to Acroseal. Other factors as the amount of tooth structure remaining, the agents used for the removal of smear layer and instrumentation techniques may alter the tooth resistance to fracture.

Conclusion:

Ketac-Endo shows higher fracture resistance values in comparison to Acroseal.