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AIM: The aim of this study was to evaluate the number of intracanal bacteria extruded apically after instrumentation with three different nickel-titanium rotary instruments. MATERIALS AND METHODOLOGY: Forty freshly extracted mandibular premolars were selected, access cavities were prepared, and the teeth were mounted in the bacterial collection apparatus. Root canals were contaminated with a suspension of Enterococcus faecalis and incubated for 24 h at 37°C. The contaminated teeth were divided into four groups of 10 teeth each according to the rotary system used for instrumentation: Group 1: ProTaper universal files, Group 2: MTwo files, Group 3: ProTaper Next files, and Group 4: Control group (no instrumentation). Bacteria extruded after preparations were collected into vials. The number of colony-forming units (CFUs) was determined for each sample. STATISTICAL ANALYSIS: The data obtained were analyzed using the one-way analysis of variance followed by post hoc Tukey's test with a P = 0.05 as the level for statistical significance. RESULTS: The results suggested a statistically significant difference in the number of CFUs between four experimental groups (P < 0.001). CONCLUSION: Least amount of bacterial extrusion was seen in ProTaper Next Group while more bacterial extrusion was seen in MTwo Group.
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AIM: The purpose of this study was to evaluate the effectiveness of three desensitizing agents on dentinal tubule obliteration and their durability in use on the dentinal tubules. MATERIALS AND METHODS: Sixty specimens were obtained from 30 extracted sound human maxillary first premolars. Each tooth was mesiodistally sectioned to obtain 30 buccal and 30 lingual surfaces, and enamel was removed in order to simulate hypersensitive dentin. Specimens were divided into four groups with 15 specimens each. Group 1 samples were immersed in artificial saliva, Group 2 samples were coated with Vivasens, Group 3 samples were coated with VOCO Admira Protect, and Group 4 samples were coated with Neo Active Apatite suspension. These specimens were examined under scanning electron microscope (SEM) to find out the occluding ability of the respective products. The specimens were brushed to find out their durability for 1 week and 1 month and were examined under SEM. STATISTICAL ANALYSIS: The results were statistically analyzed by analysis of variance (ANOVA) and Tukey's test. RESULTS: Group 1 differed significantly from the Vivasens, Admira, and Neo Active Apatite groups at 5% level of significance (P < 0.05). The Vivasens group differed significantly from the Admira and Neo Active Apatite groups at 5% level of significance (P < 0.05). CONCLUSION: The Ormocer-based Admira Protect showed the best results.
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BACKGROUND: Lack of seal and adhesion between the final restoration and tooth structure adversely affects the results of root canal treatment. Lots of adhesive bonding agents are marketed to overcome this deficiency and achieve successful restoration. So the study compares and evaluates the micro shear bond strength of coronal dentin and pulp chamber dentin using three different generation dentin bonding systems and to know clinical efficiency for clinical use. MATERIALS AND METHODS: DIFFERENT GENERATION DENTIN BONDING SYSTEMS USED WERE: (1) One bottle total etch system (XP Bond-5(th) generation), (2) Two-step self-etch system (Clearfil SE Bond-6(th) generation) and (3) All-in-one system (G Bond-7(th) generation). Thirty human mandibular molars were collected out of which sixty samples were prepared by sectioning each tooth into coronal dentin and pulpal floor dentin. They were divided into two major groups. Group I: 30 Coronal dentin samples. Group II:30 Pulpal floor dentin samples. Both the groups were further subdivided depending on the bonding agent used. Subgroup Ia:XP Bond, Subgroup Ib:Clearfil SE Bond, Subgroup Ic:G Bond, Subgroup IIa:XP Bond, Subgroup IIb:Clearfil SE Bond, Subgroup IIc:G Bond. Resin composite was bonded to these samples and tested for micro-shear bond strength. The mean bond strengths and standard deviations were calculated and analyzed using one-way ANOVA test and Student's t-test (unpaired) and honestly significant difference post-hoc tests. RESULTS: Coronal dentin showed higher values of micro shear bond strength than the pulpal floor dentin. All-in-one system (G Bond) showed least bond strength values to both the regions coronal dentin and pulpal floor dentin. CONCLUSION: Factors affecting the shear bond strength are dependent on material (adhesive system), substrate depth and adhesive/depth interaction. Hence composition and substrate treatment should be considered for good adhesive. Chemical composition of adhesive system determines clinical successes.
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INTRODUCTION: Candida albicans is the most commonly isolated fungi from the oral cavity. It is the most infective to various intracanal medicaments and is considered as invasive yeast. Sodium dichloroisocyanurate (NaDCC) which is used as a disinfectant and as a biocide in treating potable water has similar action to that of sodium hypochlorite against microbes. The aim of the present study is to compare the effectiveness of calcium hydroxide and NaDCC against Candida albicans. MATERIALS AND METHODS: After obtaining the stock cultures of Candida, the isolates were divided into six groups which were exposed to different concentrations of NaDCC and calcium hydroxide Ca(OH)2. Group 1 consisted of the isolates which were subdivided into three groups, subjected to three different concentrations of NaDCC. Group 2 also consisted of three subgroups exposed to three different concentrations of Ca(OH)2. Group three consisted of three subgroups which were exposed to three different concentrations of combinations of both NaDCC and Ca(OH)2. RESULTS: The results of the present study show that calcium hydroxide was totally ineffective at all concentrations and NaDCC was effective and also the combination of both was shown to be effective. CONCLUSION: NaDCC alone was effective at all concentrations and the combination with Ca(OH)2 was found to be less effective. Ca(OH)2 was totally ineffective.