Calcium phosphate cement as an alternative for formocresol in primary teeth pulpotomies.

Background: Formocresol remains to be the preferred medicament in pulpotomy, despite the concerns regarding tissue devitalization and systemic toxicity. Several materials were used as alternatives, but none proved significantly advantageous. Of recent, calcium phosphate cement (CPC) has been projected as an ideal pulpotomy material considering its tissue compatibility and dentinogenic properties. This study explores the suitability of a CPC formulation for pulpotomy, in comparison with formocresol. Materials and Methods: This comparative case study included 10 children (8-12 age group) having a pair of non-carious primary canines (both maxillary and mandibular) posted for extraction. Pulpotomy was performed with CPC in the right canines and formocresol in the left and sealed with IRM® (Dentsply). The teeth were extracted at 70 ± 5 days and sectioned and stained for the histopathological evaluation. Parameters such as pulpal inflammation, tissue reaction to material, dentine bridge formation, location of dentine bridge, quality of dentine formation in bridge, and connective tissue in bridge etc. were evaluated. Results: The histological assessment after 70 days showed no statistically significant difference between the two groups in any of the parameters. However, CPC gave more favorable results in pulpal inflammation, with a lower score of 1.6 against 2.6 for formocresol. CPC samples showed better formation of dentine bridge in quantity and quality. The mean scores for CPC for the extent of dentine bridge formation, quality of dentine bridge and connective tissue in the bridge, were 2.0, 1.4, and 1.2 respectively, whereas the corresponding values for formocresol were 0.8, 0.2, and 1.0. Conclusion: CPC is more compatible to pulp tissues than formocresol and it shows good healing potential. CPC is capable of inducing dentine formation without an area of necrosis.

Preclinical and early clinical experience with a biodegradable polymer-based, rapamycin-eluting, Indian drug-eluting coronary stent: the BIO-RAPID study.

OBJECTIVE: To evaluate the performance of a biodegradable polymer based rapamycin-eluting coronary stent in a porcine model and demonstrate its safety and efficacy in the treatment of patients with de novo coronary stenosis. BACKGROUND: The indefinite presence of the polymer after the implantation of drug-eluting stents may initiate and sustain inflammation and contribute to the occurrence of late complications. METHODS: Seven study stents and 5 polymer-coated (control) stents were implanted in porcine carotid arteries. Histomorphometric analysis was performed 8 weeks after stent implantation. After establishing the safety of the stent in the animal model, a single-center, non-randomized study in patients with de novo coronary artery lesions was performed. Forty-nine stents were implanted in 43 patients. The 6-month clinical follow-up was 91% (39/43) and angiographic follow-up was 67% (29/43). The primary safety endpoint was the occurrence of 30-day major adverse cardiovascular events (MACE) and the principal efficacy endpoint was the 6-month angiographic late loss and binary restenosis rate. RESULTS: In the porcine model, the study stent showed acceptably low injury, inflammation and fibrin scores. There was a quantitative reduction in neointimal hyperplasia which was not statistically different from the control stent. However, in the first-in-man evaluation, there was significant suppression of intimal growth as evidenced by an angiographic late loss of 0.28 +/- 0.45 mm at 6 months. The restenosis rate was 10.3% (3/297). There was no death, stent thrombosis or myocardial infarction at 30 days or at 6 months. The 6-month target lesion revascularization rate was 3.47 percent; (1/29). CONCLUSION: This preclinical and early clinical experience demonstrates the safety and efficacy of a novel biodegradable polymer-based rapamycin-eluting coronary stent.

Characterisation and quantification of mucosal vasculature in oral submucous fibrosis.

AIM: Quantitative assessment of the mucosal vascularity in oral sub mucous fibrosis (OSF) by image analysis using OPTIMAS ver 6.0 software. The vascularity was assessed by estimating (a) the mean vascular density, (b) the mean vascular area percentage, and (c) the mean vascular luminal diameter. SUBJECT AND METHODS: Twenty (20) OSF and ten (10) age and sex matched healthy volunteers comprised the study group. The 5 microm thick H and E stained mucosal sections were examined and quantified in an image analyzer for number, size, density of vessels, and percentage of vascular area using an area morphometry tool. ANOVA is used to test equality of several means without affecting Type 1 error. RESULT: The mean vascular density is found to be more or less same in the test and control samples (F = 0.82, P>0.05). The mean vascular percentage area shows an increasing trend as the disease progresses (F = 8.63, p<0.01). The mean vascular luminal diameter also shows an increasing trend as the disease progresses (F = 34.1, p<0.001). CONCLUSION: The usual tissue reaction resultant to ischaemia / hypoxia does not seem to operate in this disease, which is preconditioned by significant stromal changes as part of the disease process. The mean vascular dilatation noted is assumed to be an adaptive response to compensate tissue ischaemia/hypoxia.

In vivo biocompatibility of aliphatic segmented polyurethane in rabbit.

An aliphatic segmented polyurethane with soft to hard segment ratio 3 was synthesised using hexamethylene diisocyanate, polypropylene glycol 400 and 1,4-butane diol.A stainless steel cage implant system has been used to study the in vivo biocompatibility of this polyurethane. United States Pharmacopoeia negative control polyethylene was used for the comparison. Three cages, one with polyurethane another with United States Pharmacopoeia polyethylene and the third control empty cage were implanted subcutaneously in the dorsal aspect of rabbits. The inflammatory exudate surrounding the material was aspirated from the cages on 4, 7, 14 and 21 days after implantation. The total protein content in the exudate aspirated from all the 3 cages was significantly higher at 7 days than in the reported normal rabbit serum of New Zealand white rabbit but equal to that of our rabbit colony. The albumin concentration was lower in the initial period but increased at 21 days post implantation period in all the cages. Concentration of α1, α2 and γ-globulin also decreased in all cages at 21 days. Neutrophils were predominant in all the exudates aspirated from polyurethane, polyethylene and empty control cages during whole implantation period. This is attributed to the profound effect of the cages on the surrounding vasculature. Macrophage was found to be seen during acute phase of inflammation due to the migration of macrophage along with neutrophil towards the inflammatory lesion. The percentage of neutrophils showed a faster decline in the cage containing polyethylene at 21 days. The extra cellular alkaline phosphatase activity, though higher in exudate from cages containing polyurethane at 14 days post implantation, was same in all 3 cages at 21 days. Leucine amino peptidase activity was found to be decreased at 21 days of post implantation time though the empty control cage exhibited an increase at 14 days post implantation. The inflammatory response at 21 days was similar in polyurethane and the control polyethylene.