The Comparative Evaluation of the Post-Antimicrobial Effect of MTAD ® and 2% Chlorhexidine against Enterococcus faecalis of Permanent Teeth with Necrotic Pulp.

AIM: Enterococcus faecalis is one of the most resistant bacteria in necrotic teeth. That's why the goal of this study was to determine the post-antibiotic effect of MTAD®& 2% Chlorhexidine® as root canal irrigating solution on clinical isolates of E. faecalis from infected root canals of permanent teeth, using the spectrophotometric technique. MATERIAL AND METHODS: The antibacterial efficacy of Chloramphenicol 30 mcg, Nitrofurantoin 300 mcg, Vancomycin 5 mcg, Amoxicillin/clavulanic acid 30 mcg and Ofloxacin 5 mcg against E. faecalis was compared using the Disc diffusion method. Patients were selected for this study with permanent necrotic teeth. The sterile paper point was inserted inside the infected root canal and left for 60 seconds; to obtain the microbiological sample. Postantibiotic effect of MTAD® and 2% Chlorohexidine® on E. faecalis was compared. The absorbance of bacterial growth was examined for both irrigating solutions during the first 10 hours with an hour interval, and then tested at 48, 72, 96 up to 240 hours. RESULTS: The results showed that during the first 10 hours, MTAD® showed immediate antibacterial effect and maintained its higher antibacterial activity than 2% chlorohexidine®. After 48, 72, 96 and 240 hours, both MTAD® and 2% chlorohexidine® showed the same prolonged action of post-antibiotic effect against E. faecalis with a non-significant difference. According to Antibiotic sensitivity, the results revealed MTAD® is the most effective antimicrobial drug, showing the highest zone of inhibition, followed by 2% Chlorhexidine and Nitrofurantoin 300 mcg which showed the same inhibitory activity. CONCLUSION: From the current study, it can be concluded that MTAD® has a strong bactericidal effect against E. faecalis and showed the highest zone of inhibition.

In-vitro and in-vivo, cytotoxicity evaluation of cast functionally graded biomaterials for dental implantology.

An innovative technique of casting the titanium implant alloys and its calcium phosphate coating using centrifugal casting method was proposed in the current study. This one-step, self-coating technique results in formation of functionally graded biomaterials (FGBMs) of calcium phosphate/Titanium alloys. Two groups of samples (Group 1 and Group 2) were prepared utilizing self-coated titanium­niobium (Ti-6Al-7Nb) and titanium- vanadium (Ti-6Al-4V) alloys respectively. The cast samples were then prepared for in-vitro cytocompatibility evaluation, in-vivo systemic toxicity and osseointegration evaluation. Cytocompatibility was examined in-vitro on human bone osteosarcoma cells (Saos-2). In-vivo surgical implantation of the samples in the mandible of the experimental dogs was correspondingly implemented. Tests for systemic toxicity, X-ray images, Dual Energy X-ray Absorptiometry (DEXA) and histopathological analysis were obtained for each dog's mandible sample. In-vitro cytocompatibility studies revealed high cytocompatibility of Group 2 in comparison to Group 1. In-vivo results proved safety of Group 2 as regards to systemic toxicity. On the other hand, results of the X-ray images, DEXA and histopathological analysis revealed comparable osseointegration potential of both groups. These results suggest the use of Group2-FGBMs in dental implant manufacturing and prove that FGBMs prepared by centrifugal casting as self-coated implants have good biocompatibility and osseointegration capability.

Injectable nanoamorphous calcium phosphate based in situ gel systems for the treatment of periapical lesions.

Nonsurgical local treatment of a periapical lesion arising from trauma or bacterial infection is a promising innovative approach. The present study investigated the feasibility of developing injectable amorphous calcium phosphate nanoparticles (ACP NPs) and ACP NPs loaded with an anti-inflammatory drug; ibuprofen (IBU-ACP NPs) in the form of thermoreversible in situ gels to treat periapical lesions with the stimulation of bone formation. NPs were produced by a spray-drying technique. Different formulations of Poloxamer 407 were incorporated with/without the produced NPs to form injectable gels. A drug release study was carried out. A 3 month in vivo test on a dog model also was assessed. Results showed successful incorporation of the drug into the NPs of CP during spray drying. The particles had mean diameters varying from 100 to 200 nm with a narrow distribution. A drug release study demonstrated controlled IBU release from IBU-ACP NPs at a pH of 7.4 over 24 h. The gelation temperature of the injectable in situ gels based on Poloxamer 407 was measured to be 30 °C. After 3 months of implantation in dogs, the results clearly demonstrated that the inclusion of ACP NPs loaded with IBU showed high degrees of periapical bone healing and cementum layer deposition around the apical root tip.