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.

Effect of four different intracanal medicaments on the apical seal of the root canal system: a dye extraction study.

AIM: The aim was to determine the effect of four different intracanal medicaments on the apical seal of the root canal system in vitro. METHODOLOGY: Fifty freshly extracted intact human permanent maxillary central incisors were collected, stored and disinfected. The root canals were prepared to a master apical size of number 50 using step back technique. Depending upon the intracanal medicament used, the teeth were divided randomly into five groups of 10 teeth each including one control group and four experimental groups. Group A: No intracanal medicament. Group B: Calcium hydroxide powder mixed with distilled water. Group C: Calcium hydroxide gutta percha points (calcium hydroxide points). Group D: 1% chlorhexidine gel (hexigel). Group E: Chlorhexidine gutta percha points (Roeko Activ Points). The medication was left in canals for 14 days. Following removal of the intracanal medicament, all the groups were obturated with lateral compaction technique. The apical leakage was then evaluated using dye extraction method with the help of a spectrophotometer. RESULTS: RESULTS were statistically analyzed using Kruskal-Wallis and Mann-Whitney U-test, which showed statistically significant difference among the five groups tested. CONCLUSION: It can be concluded from this study that the control group showed least amount of leakage, whereas the 1% chlorhexidine gel group showed maximum amount of leakage. Apical leakage was observed with all the experimental groups with little variations in between them. Under the parameters of this study, it can be concluded that use of intracanal medicaments during endodontic treatment has a definite impact on the apical seal of the root canal system.

Morphological evaluation of new total etching and self etching adhesive system interfaces with dentin.

AIM: The purpose of this study is to evaluate the resin-dentin interface, quality of the hybrid layer of total-etching and self-etching adhesive systems under scanning electron microscopy (SEM). MATERIALS AND METHODS: Class V cavities were prepared in 40 extracted human molars. In Group I XP bond (Dentsply), in Group II Adper Single Bond II (3M ESPE), in Group III Adper Easy One (3M ESPE), and in Group IV Xeno V (Dentsply) were applied. Teeth were restored with resin composite, subjected to thermocycling, and sectioned in Buccolingual plane. The samples were demineralized using 6N HCl, for 30 sec, and deproteinized with 2.5% NaOCl for 10 min, gold sputtered, and viewed using a scanning electron microscope. RESULTS: Among the total-etch systems used, the XP Bond showed a clear, thick hybrid layer, with long resin tags and few voids. Among the self-etch adhesive systems, the Xeno V did not show a clearly recognizable hybrid layer, but there were no voids and continuous adaptation was seen with the dentin. CONCLUSION: The adaptation of self-etch adhesives to the resin-dentin interface was good without voids or separation of phases; showing a thin, continuous hybrid layer.

Assessment of antibacterial properties of newer dentin bonding agents: An in vitro study.

AIM: To evaluate and compare the antibacterial activity of newer dentin bonding agents on Streptococcus mutans using the direct contact test. MATERIALS AND METHODS: Streptococcus mutans was used as test organism and a direct contact test was performed. The dentin bonding agents to be tested were grouped as Group I, Clearfil Protect Bond, Group II, Adper Easy One, and Group III, Prime and Bond NT. For the direct contact test, three microtiter plates consisting of 96 wells each were taken (288 wells). These wells were divided into three groups of 96 wells; 16 wells of a microtiter plate were utilized, of which four were designated as 'A' wells (with the dentin bonding agent and bacterial suspension), another four as 'B' wells (without the dentin bonding agent, but with the bacterial suspension), another four as the 'C' wells (with the tested material, but without bacteria, which served as the negative control), and the remaining four as the 'D' wells (without the dentin bonding agent, which served as the positive control). Each group was treated with their respective bonding agents as per the manufactures instructions. Broth of 15 µL was then transferred from the A wells into an adjacent set of B wells containing fresh medium (215 µL). This resulted in two sets of four wells for each tested material containing an equal volume of liquid medium, so that bacterial growth was monitored both in the presence and in the absence of the tested material. The plate was placed for incubation at 37°C in the microplate reader and the optical density in each well was measured at 600 nm. The readings were taken at regular intervals. (Every 30 minutes for 16 hours). RESULTS: The Dentin bonding agents evaluated in this study showed different inhibitory effects. Clearfil Protect Bond and Prime and Bond NT were most effective, and Adper Easy One was least effective against Streptococcus mutans. INTERPRETATION AND CONCLUSION: The Dentin bonding agents evaluated in this study showed different inhibitory effects. Clearfil Protect Bond and Prime and Bond NT were most effective, and Adper Easy One was the least effective against Streptococcus mutans. Hence, the incorporation of antibacterial agents into the dentin bonding agents may become an essential factor in inhibiting residual bacteria in the cavity and secondary caries.

An evalution of compressive strength of newer nanocomposite: An in vitro study.

AIM: The purpose of the study is to assess and compare compressive strength of newer nanocomposites (FiltekZ350, Ceram X Mono, Ceram X Duo) with microhybrid (Tetric Ceram) and to compare difference in compressive strength of newer nanocomposites. MATERIALS AND METHODS: Forty eight specimens of composite were fabricated using customized biparpite brass mold measuring 5mm x 5mm and were grouped with twelve specimens in each Group I : Tetric Ceram, Group II: Filtek Z 350, Group III : Ceram X Mono, Group IV : Ceram X Duo. Composite resins are placed in cylindrical recesses and covered with mylar strip and are cured using QHL light curing unit. Compressive strength is evaluated using Instron machine. Results are statistically analyzed using One way Anova and Student t test. Analysis demonstrated that nanocomposites have better compressive strength than micro hybrid (P<0.001). RESULTS: Within the limitations of the study, it can be concluded that nanocomposites have better compressive strength than microhybrid composite and nanocomposite showed optimal compressive strength of 312 - 417 Mpa.

Assessment of antibacterial activity of self-etching dental adhesive systems: An in vitro study.

AIM: To evaluate and compare the antibacterial activity of polymerized, two-step, self-etching and one-step, self-etching adhesive systems by using the direct contact test after one, seven, and fourteen days. MATERIALS AND METHODS: The direct contact test was used to evaluate the antibacterial activity of Clearfil Protect Bond, Adper SE Plus, Clearfil SE Bond, and Adper Easy One on Streptococcus mutans after aging the samples in phosphate-buffered saline for one, seven, and fourteen days. Statistical analysis included the one-way Anova and Tukey's multiple comparison tests. RESULTS: Among the tested materials, Clearfil Protect Bond exhibited an antibacterial effect for seven days when in contact with S. mutans. None of the adhesive systems exhibited any antibacterial effect after 14 days. CONCLUSION: The incorporation of antibacterial agents into dentine-bonding agents may become an essential factor in inhibiting residual bacteria in the cavity following a cavity disinfection procedure, and it could be recommended in situations where total disinfection of cavity is not accomplished due to lack of accessibility.

Evaluation of depth of cure and knoop hardness in a dental composite, photo-activated using different methods.

The study aimed at evaluating the depth of cure and knoop hardness of a microfine-hybrid composite resin that was photo-activated using different methods. A bipartite brass mold was filled with composite resin and photo-activation was performed using four methods: (1) Intermittent method using quartz tungsten halogen (QTH) light curing unit (LCU) (2) Continuous method (QTH) (3) Exponential method (QTH) (4) Continuous method using light-emitting diode (LED). Depth of cure was measured at the unexposed bottom surface of the specimen using microtester as a penetrometer. The surfaces exposed to light were subjected to knoop hardness testing, using a digital microhardness tester. Knoop hardness measurements were obtained at the top surface and at depths of 1, 2, 3, 4 and 5 mm. The data was analyzed using anova and Tukey's test (5%). Results showed that the depth of cure was higher with the intermittent method (QTH), followed by the continuous method (QTH), the exponential method and the continuous method (LED). At the top surface and up to 1 mm, continuous method (LED) demonstrated the highest knoop hardness number (KHN). At 2 mm and up to 5 mm, intermittent method (QTH) presented the highest KHN and continuous method (LED) showed the lowest KHN. At all depths, continuous method (QTH) showed higher KHN, as compared to the exponential method (QTH), except at 2 mm where both showed no significant difference.

The influence of salivary contamination on the shear bond strength of two newer generation dentin bonding agents - An in vitro study.

BACKGROUND AND OBJECTIVES: To investigate whether salivary contamination during various stages of the bonding procedures of Xeno III and Clearfil SE Bond influences shear bond strength. MATERIALS AND METHODS: THE OCCLUSAL SURFACES OF THIRTY SIX MAXILLARY PREMOLAR TEETH WERE GROUND AND DIVIDED INTO TWO GROUPS CONTAINING EIGHTEEN SPECIMENS EACH, WHICH WAS SUBDIVIDED INTO THREE SUB GROUPS: Group I - Xeno III, Group II - Clearfil SE Bond, Subgroup A - Uncontaminated (control), Subgroup B - Contaminated with saliva before application and light curing, Subgroup C - Contaminated with saliva after light curing. Composite resin Filtek Z350 was packed using Teflon mold cured and subjected to shear bond strength analysis using universal Instron machine. RESULTS: Statistical analysis was made using One-way ANOVA and Tukeys HSD test. Clearfil SE Bond showed very high statistically significant reduction in the bond strength, when salivary contamination took place after light curing; whereas, Xeno III showed very high statistically significant reduction when salivary contamination took place before application and light curing. CONCLUSION: Clearfil SE Bond showed more tolerance to salivary contamination of dentin and higher shear bond strength value, when compared to Xeno III.