Effects of traditional and novel proteolytic agents on tissue dissolution and dentine microhardness.

The study aimed to evaluate the tissue-dissolving ability of papain and bromelain with respect to that of sodium hypochlorite (NaOCl) at the temperatures of 25°C and 60°C. The study also assessed the effects of these proteolytic agents on radicular dentine microhardness. Warming NaOCl, papain and bromelain solutions resulted in significant tissue dissolution at all time intervals (p < 0.001). At 60°C, bromelain showed significantly higher tissue weight loss at every time interval when compared to NaOCl (p < 0.001). All of the three organic tissue dissolvents reduced the microhardness at 1 hr when compared to their respective baseline values. The reduction in microhardness from the baseline reading was statistically significant only in the papain group at 30 min (p = 0.018) and at 60 min (p = 0.03) when compared to the control group. Hence it was concluded that bromelain exerted superior tissue dissolution action, especially when warmed, with minimal effect on dentine microhardness.

Effectiveness of laser fluorescence-based device in detecting the extent of re-mineralisation in primary teeth compared to the conventional method: An In vitro study.

Background: Laser fluorescence (LF)-based clinical device DIAGNOdent™ is at present being used to detect caries. Can the same be used to detect therapeutic remineralisation of early white spot lesions? Aims: To explore the feasibility of using LF-based device in monitoring the changes following remineralisation of demineralised primary teeth. Materials and Method: The sample number for the present experimental in vitro study was 10. The LF based device readings were correlated with surface microhardness (SMH) test values to evaluate its efficiency. SMH analysis was performed using a microhardness tester (Tescol-HT1000AD). All the samples were demineralised, followed by remineralisation using fluoride varnish and pH cycling. The data was analysed using the Statistical Package for the Social Sciences (SPSS) version 17.0 (IBM SPSS®) software. Paired t-test was performed to compare laser fluorescence readings and SMH test result values at baseline, after demineralisation, and after remineralisation. Pearson's correlation was used to compare the relation between the laser fluorescence and SMH test. Results: A good negative correlation was seen between the two methods at the baseline readings even though it was not statistically significant (P = 0.069). A positive correlation between the methods existed following demineralisation which was not significant (P = 0.074). The correlation between the parameters following remineralisation showed a moderate negative correlation but was not significant (P = 0.55). Conclusion: DIAGNOdent™ values at baseline, after demineralisation, and after remineralisation was consistent with SMH values. Thus, DIAGNOdent™ can be explored to provide chairside assistance in identifying remineralisation of white spot lesions.

Radiation mitigating activities of Psidium guajava L. against whole-body X-ray-induced damages in albino Wistar rat model.

In the present study, we investigated radiation mitigating activities of Psidium guajava L. (P. guajava) against whole-body X- ray induced damages in albino Wistar rat model. The animals were orally administered with 200 mg/kg bodyweight of hydroalcoholic leaf extract of P. guajava for five consecutive days and on the fifth day, after the last dose of extract administration, animals were exposed to 4 Gy of X-rays. Rats were sacrificed 24 h post X-ray irradiation. The radiomitigating activity of the herb extract was assessed by micronucleus assay, histopathology of the small intestine and hematological parameters. Hepatic cyclooxygenase-2 (COX-2), interleukin-6 (IL-6) and interleukin -10 (IL-10) levels were assayed to validate the anti-inflammatory property. Biochemical estimations were also performed in RBC lysates to corroborate antioxidant properties in the leaf extract. HPLC analysis of crude extract confirmed the presence of standard flavonoid quercetin. Our results indicated that radiation elevated COX-2, IL-6 and decreased IL-10 levels and also induced micronucleus formation in polychromatic erythrocytes, simultaneously impairing hematological parameters along with erythrocyte antioxidants. The animals pre-treated with P. guajava exhibited a significant decrease in the COX-2 (P ≤ 0.01), IL-6 levels (P ≤ 0.05) and also displayed significant increase in the hepatic IL-10 levels (P ≤ 0.01). Pre-treatment with plant extract improved antioxidant enzyme activities, hematological parameters and reduced the intestinal damage by recovering the architecture of the small intestine. Moreover, extract also rendered protection against radiation induced DNA damage, as evidenced by the significant (P ≤ 0.01) decrease in the percentage of radiation-induced micronucleus in polychromatic erythrocytes. Furthermore, the herb extract treatment increased radiation LD50/30 from 6.6 Gy to 9.0 Gy, offering a dose reduction factor (DRF) of 1.36. Our findings for the first time propose the beneficial use of P. guajava as a radioprotector against X-ray induced damage.