Tensile Strength of Novel Experimental Hydrophilic Vinyl Polysiloxane Impression Materials Compared to Control and Commercial VPS Impression Materials

Objective: To measure the tensile strength of novel experimental hydrophilic (medium bodied) vinyl polysiloxane impression materials developed from ab initio in comparison to control and commercial vinyl polysiloxane impression materials. Materials and Methods: This experimental study was conducted at the Department of Oral Growth and Development, Bart’s and The London School of Medicine and Dentistry, Queen Mary, University of London, UK from 1st Oct 2010 to 28th February 2014. Five novel experimental (medium bodied) VPS impression materials (Exp-I, II, III, IV and V) were developed and evaluated for their effect as crosslinking agent and surfactant on the tensile strength and percent elongation-at-break in comparison to control and three commonly used commercial (medium bodied) VPS impression materials (Aquasil Ultra Monophase, Elite HD Monophase, Extrude. These properties were evaluated using Tenius Olsen (mechanical testing machine). Results: Aquasil Ultra Monophase (Aq M) had a significantly higher Ultimate Tensile Strength (UTS) compared to all commercial and Experimental VPS. Although Exp-III showed the lowest UTS among all the materials but this was only significant for Aq M. On comparing Exp-I (control) with Exp-II, after adding TFDMSOS into Exp-II there was a slight, but not significant, increase in UTS. After adding the surfactant to hydrophilic Exp-III, IV and V, the UTS decreased slightly, but not significantly, compared to Exp-II. After addition of cross-linking agent (TFDMSOS) there was a significant increase in elongation-at-break of Exp-II compared to the control (Exp-I), which was further significantly increased after incorporating the surfactant (Rhodasurf CET-2) in the Exp hydrophilic VPS formulations (Exp-III, IV and V). Elongationat-break was significantly increased after incorporating the surfactant (Rhodasurf CET-2) in the Exp hydrophilic VPS formulations (Exp-III, IV and V) compared to Exp-II. Conclusion: All Exp VPS had significantly higher % elongation-at-break (more than double) than commercial VPS. Percentage elongation-at-break further increased significantly after adding Rhodasurf CET-2 (Surfactant).&nbsp

Comparison of Endodontic Pain observed with Sodium Hypochloride, Hydrogen peroxide and Norman Saline based Root canal irrigants

Objective: To compare frequency and intensity of endodontic pain with sodium hypochlorite, hydrogen peroxide and normal saline groups. Method:105 subjects were randomly allocated to 3 study arms. Group A (Sodium Hypochlorite), Group B (Hydrogen Peroxide) & Group C (Normal saline).Data regarding endodontic pain was recorded by asking the patient to mark on the Visual Analogue Scale (VAS) according to the severity of pain on the proforma provided. Results:The minimum Intensity of pain was 0 and maximum was 10 with mean and standard deviation were 3.43  3.576 VAS. Endodontic pain was present in 12/35 (34.3%), 24/35 (68.6%), 30/35 (85%) patients of Group’s A, B, C respectively. Significant difference between groups with respect to Intensity of pain (VAS) was shown by one-way ANOVA. For Group A the Intensity of pain (VAS) was 82.38  4.34 and for Group B, C the Intensity of pain (VAS) were 4.37  3.456 and 6.11  3.197 respectively. Conclusions:Sodium Hypochlorite was much better than Hydrogen peroxide and normal saline in the management of endodontic pain in terms of incidence and intensity

Single Versus Multiple Sittings Endodontic Treatment Using Rotary Nickle Titanium Instruments

Objective: To access if there is considerable difference in an incidence & severity of the post obturation pain afterwards the single and multiple-visit RCT. Methodology: Study was directed at operative dentistry department, Rawal dental hospital, Islamabad. Sample size was calculated using WHO calculator. 156 patients were randomly allocated into 2 groups, 78 each. Before treatment all partakers were said to put mark on a horizontal scale to indicate pain intensity. After treatment participants are inquired about pain after twenty-four hours of treatment via graded using Visual-analogue scale. Results: Males were 93 (59.6%) while females were 63 (40%). Anterior teeth were 80 (51%) while posterior teeth were 76 (48 %). Mean VAS & S.D of Group 1 was 9.12 & 1.98, while for Group 2 was 8.76 & 1.03 pre-operatively. When talking about 24 hours post-operatively, Mean VAS & S.D of Group 1 was 5.58 & 1.92, while for Group 2 was 4.86 & 1.18 respectively. Independent sample t-test exposed statistically in-significant variation in a pre and post-operative pain levels in both groups Conclusion: Pain incidence was less in multi-visit group than a single-visit, which was not significant statistically. Keywords: Endodontic treatment, RCT, Single visit, Visual-analogue scale.&nbsp