Comparing the effect of a desensitizing material and a self-etch adhesive on dentin sensitivity after periodontal surgery: a randomized clinical trial

OBJECTIVES: This double-blind randomized placebo-controlled clinical trial evaluated the ability of a desensitizing agent and a self-etch adhesive on cervical dentin sensitivity (CDS) after periodontal surgery. MATERIALS AND METHODS: Ninety hypersensitive teeth of 13 subjects were included in the study. After periodontal surgery, the teeth of each posterior sextant treated with one of the following materials: G1: Clearfil S³ Bond (Kuraray Dental), G2: Gluma Desensitizer (Heraeus Kulzer), and G3: placebo (water). The sensitivity was assessed using evaporative stimuli before treatment (baseline, T0), 1 day after treatment (T1), after 1 week (T2), and after 1 month (T3) according to visual analog scale (VAS). RESULTS: Following the treatment, all the 3 groups showed significant reduction of CDS in T1 compared to T0. Reduction of CDS between T1 and T2 was observed only in G1 but there was no significant difference between T2 and T3 in this group. Although we observed a significant difference in T3 compared to T1 and T2 in G2 and G3, comparison of treatment groups in each assessment time showed a significant difference only in T3. According to paired comparison, this was due to the difference between G2 and G3. CONCLUSIONS: Dentin sensitivity following periodontal surgery will decrease spontaneously over time, but treating the sensitive teeth with Gluma Desensitizer and Clearfil S³ Bond can have some benefits.

[Effect of thermo-mechanical load cycling on the fracture strength of upper central incisor restored with three different types of glass-fiber posts]

The aim of this study was to evaluate the fracture strength of restored teeth with three different types of E glass-fiber posts after thermo-mechanical loading. Sixty extracted upper central incisor human teeth, with similar size, were selected and divided into three groups [n=20]. Endodontic treatment was done in all groups and crowns were sectioned from 2 mm above CEJ. Then one type of posts in each group [Anthogyr, Svensk, Hetco] cemented using Panavia cement and the crowns were restored with a composite. The specimens in each group were thermocycled for 6000 cycles [5-55°C] and subjected to 1200000 cycles of mechanical loadiong in an artificial mouth machine. Then the fracture strength was measured and data were analyzed using ANOVA and T-student test [alpha=0.05]. The mean fracture strengths in Hetco group before and after thermomechnical loading were 581.098 +/- 192.742 N and 564.74 +/- 213.59 N, in Anthogyr group were 664.358 +/- 135.878 N and 629.12 +/- 390.3 N and, in Svensk group were 780.258 +/- 379.133 N and 779.84 +/- 282.59 N, respectively. There was no significant difference between groups and also there was no significant difference in each group before and after thermo-mechanical loading [P>0.05]. Restored teeth with Hetco fiber glass post were similar in terms of the fracture strength with that of two other posts after thermo-mechnical loading